Sample records for orbit modification system

  1. Discovery Orbiter Major Modifications

    NASA Image and Video Library

    2003-08-27

    During power-up of the orbiter Discovery in the Orbiter Processing Facility, a technician moves a circuit reset on the cockpit console. Discovery has been undergoing Orbiter Major Modifications in the past year, ranging from wiring, control panels and black boxes to gaseous and fluid systems tubing and components. These systems were deserviced, disassembled, inspected, modified, reassembled, checked out and reserviced, as were most other systems onboard. The work includes the installation of the Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.”

  2. Act-and-wait time-delayed feedback control of autonomous systems

    NASA Astrophysics Data System (ADS)

    Pyragas, Viktoras; Pyragas, Kestutis

    2018-02-01

    Recently an act-and-wait modification of time-delayed feedback control has been proposed for the stabilization of unstable periodic orbits in nonautonomous dynamical systems (Pyragas and Pyragas, 2016 [30]). The modification implies a periodic switching of the feedback gain and makes the closed-loop system finite-dimensional. Here we extend this modification to autonomous systems. In order to keep constant the phase difference between the controlled orbit and the act-and-wait switching function an additional small-amplitude periodic perturbation is introduced. The algorithm can stabilize periodic orbits with an odd number of real unstable Floquet exponents using a simple single-input single-output constraint control.

  3. KSC-05pd2530

    NASA Image and Video Library

    2005-11-30

    KENNEDY SPACE CENTER, FLA. - In Orbiter Processing Facility Bay 2, the nose cap of space shuttle Endeavour is prepared for installation of thermal protection system blankets. Endeavour recently came out of a nearly two-year Orbiter Major Modification period which began in December 2003. Engineers and technicians spent 900,000 hours performing 124 modifications to the vehicle. These included all recommended return-to-flight safety modifications, bonding more than 1,000 thermal protection system tiles and inspecting more than 150 miles of wiring throughout the orbiter. Shuttle major modification periods are scheduled at regular intervals to enhance safety and performance, infuse new technology, and allow for thorough inspections of the airframe and wiring of the vehicles. This was the second of these modification periods performed entirely at Kennedy Space Center. Endeavour's previous modification was completed in March 1997.

  4. KENNEDY SPACE CENTER, FLA. - Stephanie Stilson, NASA vehicle manager for Discovery, is being filmed for a special feature on the KSC Web about the recent Orbiter Major Modification period, which included inspection, modifications and reservicing of most systems onboard Discovery, plus installation of a Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.” The orbiter is now being prepared for eventual launch on a future mission.

    NASA Image and Video Library

    2004-01-22

    KENNEDY SPACE CENTER, FLA. - Stephanie Stilson, NASA vehicle manager for Discovery, is being filmed for a special feature on the KSC Web about the recent Orbiter Major Modification period, which included inspection, modifications and reservicing of most systems onboard Discovery, plus installation of a Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.” The orbiter is now being prepared for eventual launch on a future mission.

  5. KENNEDY SPACE CENTER, FLA. - Standing on a workstand (at left) in the Orbiter Processing Facility is Stephanie Stilson, NASA vehicle manager for Discovery. She is being filmed for a special feature on the KSC Web about the recent Orbiter Major Modification period on Discovery, which included inspection, modifications and reservicing of most systems onboard, plus installation of a Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.” The orbiter is now being prepared for eventual launch on a future mission.

    NASA Image and Video Library

    2004-01-22

    KENNEDY SPACE CENTER, FLA. - Standing on a workstand (at left) in the Orbiter Processing Facility is Stephanie Stilson, NASA vehicle manager for Discovery. She is being filmed for a special feature on the KSC Web about the recent Orbiter Major Modification period on Discovery, which included inspection, modifications and reservicing of most systems onboard, plus installation of a Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.” The orbiter is now being prepared for eventual launch on a future mission.

  6. KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Stephanie Stilson, NASA vehicle manager for Discovery, stands in front of a leading edge on the wing of Discovery. She is being filmed for a special feature on the KSC Web about the recent Orbiter Major Modification period on Discovery, which included inspection, modifications and reservicing of most systems onboard, plus installation of a Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.” The orbiter is now being prepared for eventual launch on a future mission.

    NASA Image and Video Library

    2004-01-22

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Stephanie Stilson, NASA vehicle manager for Discovery, stands in front of a leading edge on the wing of Discovery. She is being filmed for a special feature on the KSC Web about the recent Orbiter Major Modification period on Discovery, which included inspection, modifications and reservicing of most systems onboard, plus installation of a Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.” The orbiter is now being prepared for eventual launch on a future mission.

  7. KSC-05pd2533

    NASA Image and Video Library

    2005-11-30

    KENNEDY SPACE CENTER, FLA. - In Orbiter Processing Facility Bay 2, United Space Alliance technician Michael Vanwart installs thermal protection system blankets in the nose cap of space shuttle Endeavour. Endeavour recently came out of a nearly two-year Orbiter Major Modification period which began in December 2003. Engineers and technicians spent 900,000 hours performing 124 modifications to the vehicle. These included all recommended return-to-flight safety modifications, bonding more than 1,000 thermal protection system tiles and inspecting more than 150 miles of wiring throughout the orbiter. Shuttle major modification periods are scheduled at regular intervals to enhance safety and performance, infuse new technology, and allow for thorough inspections of the airframe and wiring of the vehicles. This was the second of these modification periods performed entirely at Kennedy Space Center. Endeavour's previous modification was completed in March 1997.

  8. KSC-05pd2531

    NASA Image and Video Library

    2005-11-30

    KENNEDY SPACE CENTER, FLA. - In Orbiter Processing Facility bay 2, United Space Alliance technician Michael Vanwart prepares to install thermal protection system blankets in the nose cap of space shuttle Endeavour. Endeavour recently came out of a nearly two-year Orbiter Major Modification period which began in December 2003. Engineers and technicians spent 900,000 hours performing 124 modifications to the vehicle. These included all recommended return-to-flight safety modifications, bonding more than 1,000 thermal protection system tiles and inspecting more than 150 miles of wiring throughout the orbiter. Shuttle major modification periods are scheduled at regular intervals to enhance safety and performance, infuse new technology, and allow for thorough inspections of the airframe and wiring of the vehicles. This was the second of these modification periods performed entirely at Kennedy Space Center. Endeavour's previous modification was completed in March 1997.

  9. KSC-05pd2532

    NASA Image and Video Library

    2005-11-30

    KENNEDY SPACE CENTER, FLA. - In Orbiter Processing Facility Bay 2, United Space Alliance technician Michael Vanwart installs thermal protection system blankets in the nose cap of space shuttle Endeavour. Endeavour recently came out of a nearly two-year Orbiter Major Modification period which began in December 2003. Engineers and technicians spent 900,000 hours performing 124 modifications to the vehicle. These included all recommended return-to-flight safety modifications, bonding more than 1,000 thermal protection system tiles and inspecting more than 150 miles of wiring throughout the orbiter. Shuttle major modification periods are scheduled at regular intervals to enhance safety and performance, infuse new technology, and allow for thorough inspections of the airframe and wiring of the vehicles. This was the second of these modification periods performed entirely at Kennedy Space Center. Endeavour's previous modification was completed in March 1997.

  10. Space transportation system options for extended duration and power

    NASA Technical Reports Server (NTRS)

    Loftus, J. P., Jr.

    1979-01-01

    A modification kit for the Space Transportation System (STS) Orbiter is proposed to provide more power and mission duration for payloads. The power extension package (PEP) - a flexible-substrate solar array deployed on the Space Shuttle Orbiter remote manipulator system - can provide as much as 29 kW total power for durations of 10 to 48 days. The kit is installed only for those flights which require enhanced power or duration. Modifications to the Orbiter thermal control and life support systems to improve heat balance and to reduce consumables are proposed. The changes consist of repositioning the Orbiter forward radiators and replacing the lithium hydroxide scrubber with a regenerable solid amine.

  11. KENNEDY SPACE CENTER, FLA. - During power-up of the orbiter Discovery in the Orbiter Processing Facility, a technician moves a switch. Discovery has been undergoing Orbiter Major Modifications in the past year, ranging from wiring, control panels and black boxes to gaseous and fluid systems tubing and components. These systems were deserviced, disassembled, inspected, modified, reassembled, checked out and reserviced, as were most other systems onboard. The work includes the installation of the Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.”

    NASA Image and Video Library

    2003-08-27

    KENNEDY SPACE CENTER, FLA. - During power-up of the orbiter Discovery in the Orbiter Processing Facility, a technician moves a switch. Discovery has been undergoing Orbiter Major Modifications in the past year, ranging from wiring, control panels and black boxes to gaseous and fluid systems tubing and components. These systems were deserviced, disassembled, inspected, modified, reassembled, checked out and reserviced, as were most other systems onboard. The work includes the installation of the Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.”

  12. KENNEDY SPACE CENTER, FLA. - During power-up of the orbiter Discovery in the Orbiter Processing Facility, a technician turns on a switch. Discovery has been undergoing Orbiter Major Modifications in the past year, ranging from wiring, control panels and black boxes to gaseous and fluid systems tubing and components. These systems were deserviced, disassembled, inspected, modified, reassembled, checked out and reserviced, as were most other systems onboard. The work includes the installation of the Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.”

    NASA Image and Video Library

    2003-08-27

    KENNEDY SPACE CENTER, FLA. - During power-up of the orbiter Discovery in the Orbiter Processing Facility, a technician turns on a switch. Discovery has been undergoing Orbiter Major Modifications in the past year, ranging from wiring, control panels and black boxes to gaseous and fluid systems tubing and components. These systems were deserviced, disassembled, inspected, modified, reassembled, checked out and reserviced, as were most other systems onboard. The work includes the installation of the Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.”

  13. Endeavour lands atop 747 after downtime at Palmdale, CA

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The Space Shuttle Orbiter Endeavour arrives at KSCs Shuttle Landing Facility atop NASAs Boeing 747 Shuttle Carrier Aircraft (SCA) as it returns March 27, 1997 from Palmdale, Calif., after an eight-month Orbiter Maintenance Down Period (OMDP). Nearly 100 modifications were made to Endeavour during that time period, including some that were directly associated with work required to support International Space Station Operations. The most extensive of those was the installation of an external airlock to allow the orbiter to dock with the Station. Other modifications included upgrades to Endeavours power supply system, general purpose computers and thermal protection system, along with the installation of new light-weight commander and pilot seats and other weight-saving modifications.

  14. KENNEDY SPACE CENTER, FLA. - NASA Vehicle Manager for Discovery, Stephanie Stilson poses for a photo after working with a KSC Web team who were filming a special feature for the KSC Web. Stilson explained her role in the recent Orbiter Major Modification period, which included inspection, modifications and reservicing of most systems onboard. The work on Discovery also included the installation of a Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.” The orbiter is now being prepared for eventual launch on a future mission.

    NASA Image and Video Library

    2004-01-22

    KENNEDY SPACE CENTER, FLA. - NASA Vehicle Manager for Discovery, Stephanie Stilson poses for a photo after working with a KSC Web team who were filming a special feature for the KSC Web. Stilson explained her role in the recent Orbiter Major Modification period, which included inspection, modifications and reservicing of most systems onboard. The work on Discovery also included the installation of a Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.” The orbiter is now being prepared for eventual launch on a future mission.

  15. KENNEDY SPACE CENTER, FLA. - On a tour of the Orbiter Processing Facility, Center Director Jim Kennedy (left) listens to Kathy Laufenberg, Orbiter Airframe Engineering ground area manager, with United Space Alliance, about corrosion work being done on the external tank door of orbiter Endeavour. On either side of Laufenberg are Tom Roberts, Airframe Engineering System specialist, also with USA, and Joy Huff, with KSC Space Shuttle Processing. Endeavour is in its Orbiter Major Modification period, which began in December 2003.

    NASA Image and Video Library

    2004-02-25

    KENNEDY SPACE CENTER, FLA. - On a tour of the Orbiter Processing Facility, Center Director Jim Kennedy (left) listens to Kathy Laufenberg, Orbiter Airframe Engineering ground area manager, with United Space Alliance, about corrosion work being done on the external tank door of orbiter Endeavour. On either side of Laufenberg are Tom Roberts, Airframe Engineering System specialist, also with USA, and Joy Huff, with KSC Space Shuttle Processing. Endeavour is in its Orbiter Major Modification period, which began in December 2003.

  16. KENNEDY SPACE CENTER, FLA. - During power-up of the orbiter Discovery in the Orbiter Processing Facility, a technician (left) looks at the circuit breaker lights in the cabin. Discovery has been undergoing Orbiter Major Modifications in the past year, ranging from wiring, control panels and black boxes to gaseous and fluid systems tubing and components. These systems were deserviced, disassembled, inspected, modified, reassembled, checked out and reserviced, as were most other systems onboard. The work includes the installation of the Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.”

    NASA Image and Video Library

    2003-08-27

    KENNEDY SPACE CENTER, FLA. - During power-up of the orbiter Discovery in the Orbiter Processing Facility, a technician (left) looks at the circuit breaker lights in the cabin. Discovery has been undergoing Orbiter Major Modifications in the past year, ranging from wiring, control panels and black boxes to gaseous and fluid systems tubing and components. These systems were deserviced, disassembled, inspected, modified, reassembled, checked out and reserviced, as were most other systems onboard. The work includes the installation of the Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.”

  17. KENNEDY SPACE CENTER, FLA. - On a tour of the Orbiter Processing Facility, Center Director Jim Kennedy (left) looks at an external tank door corrosion work being done on Endeavour. At right, Tom Roberts, Airframe Engineering System specialist with United Space Alliance, is describing the work. At right is Kathy Laufenberg, Orbiter Airframe Engineering ground area manager,also with USA. Endeavour is in its Orbiter Major Modification period, which began in December 2003.

    NASA Image and Video Library

    2004-02-25

    KENNEDY SPACE CENTER, FLA. - On a tour of the Orbiter Processing Facility, Center Director Jim Kennedy (left) looks at an external tank door corrosion work being done on Endeavour. At right, Tom Roberts, Airframe Engineering System specialist with United Space Alliance, is describing the work. At right is Kathy Laufenberg, Orbiter Airframe Engineering ground area manager,also with USA. Endeavour is in its Orbiter Major Modification period, which began in December 2003.

  18. KSC-99padig006

    NASA Image and Video Library

    1999-09-24

    KENNEDY SPACE CENTER, FLA. -- From the Shuttle Landing Facility, the orbiter Columbia leaves Kennedy Space Center on the back of a Boeing 747 Shuttle Carrier Aircraft on a ferry flight to Palmdale, Calif. Columbia, the oldest of four orbiters in NASA's fleet, will undergo extensive inspections and modifications in Boeing's Orbiter Assembly Facility during a nine-month orbiter maintenance down period (OMDP), the second in its history. Orbiters are periodically removed from flight operations for an OMDP. Columbia's first was in 1994. Along with more than 100 modifications on the vehicle, Columbia will be the second orbiter to be outfitted with the multifunctional electronic display system, or "glass cockpit." Columbia is expected to return to KSC in July 2000

  19. KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, KSC employee Chris Moore repairs tile on the forward area of the orbiter Discovery. The vehicle has undergone Orbiter Major Modifications in the past year, which includes tile check and repair. The tiles are part of the Orbiter Thermal Protection System, thermal shields to protect against temperatures as high as 3,000° Fahrenheit, which are produced during descent for landing. Discovery is scheduled to fly on mission STS-121 to the International Space Station.

    NASA Image and Video Library

    2003-12-09

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, KSC employee Chris Moore repairs tile on the forward area of the orbiter Discovery. The vehicle has undergone Orbiter Major Modifications in the past year, which includes tile check and repair. The tiles are part of the Orbiter Thermal Protection System, thermal shields to protect against temperatures as high as 3,000° Fahrenheit, which are produced during descent for landing. Discovery is scheduled to fly on mission STS-121 to the International Space Station.

  20. KENNEDY SPACE CENTER, FLA. - On a tour of the Orbiter Processing Facility, Center Director Jim Kennedy and Deputy Director Woodrow Whitlow Jr. (center, left and right) talk with Kathy Laufenberg, Orbiter Airframe Engineering ground rea manager, and Tom Roberts, Airframe Engineering System specialist, both with United Space Alliance. At far right is Bruce Buckingham, assistant to Dr. Whitlow. They are standing in front of the aft base heatshield of Endeavour, which is in its Orbiter Major Modification period that began in December 2003.

    NASA Image and Video Library

    2004-02-25

    KENNEDY SPACE CENTER, FLA. - On a tour of the Orbiter Processing Facility, Center Director Jim Kennedy and Deputy Director Woodrow Whitlow Jr. (center, left and right) talk with Kathy Laufenberg, Orbiter Airframe Engineering ground rea manager, and Tom Roberts, Airframe Engineering System specialist, both with United Space Alliance. At far right is Bruce Buckingham, assistant to Dr. Whitlow. They are standing in front of the aft base heatshield of Endeavour, which is in its Orbiter Major Modification period that began in December 2003.

  1. KENNEDY SPACE CENTER, FLA. - On a tour of the Orbiter Processing Facility, Center Director Jim Kennedy and Deputy Director Woodrow Whitlow Jr. (center, left and right) talk with Kathy Laufenberg, Orbiter Airframe Engineering ground area manager, and Tom Roberts, Airframe Enginering System specialist, both with United Space Alliance. At far right is Bruce Buckingham, assistant to Dr. Whitlow. They are standing in front of the aft base heatshield of Endeavour, which is in its Orbiter Major Modification period that began in December 2003.

    NASA Image and Video Library

    2004-02-25

    KENNEDY SPACE CENTER, FLA. - On a tour of the Orbiter Processing Facility, Center Director Jim Kennedy and Deputy Director Woodrow Whitlow Jr. (center, left and right) talk with Kathy Laufenberg, Orbiter Airframe Engineering ground area manager, and Tom Roberts, Airframe Enginering System specialist, both with United Space Alliance. At far right is Bruce Buckingham, assistant to Dr. Whitlow. They are standing in front of the aft base heatshield of Endeavour, which is in its Orbiter Major Modification period that began in December 2003.

  2. Space Shuttle power extension package

    NASA Technical Reports Server (NTRS)

    Loftus, J. P., Jr.; Craig, J. W.

    1980-01-01

    A modification kit for the Space Transportation System (STS) Orbiter is proposed to provide more power and mission duration for payloads. The power extension package (PEP), a flexible-substrate solar array deployed on the Space Shuttle Orbiter remote manipulator system, can provide as much as 29 kW total power for durations of 10 to 48 days. The kit is installed only for those flights which require enhanced power or duration. The PEP is made possible by development of the flexible-substrate array technology and, in itself, contributes to the technology base for the use of large area solar cells. Modifications to the Orbiter thermal control and life support systems to improve heat balance and to reduce consumables are proposed. The changes consist of repositioning the Orbiter forward radiators and replacing the lithium hydroxide scrubber with a regenerable solid amine.

  3. KSC-99padig007

    NASA Image and Video Library

    1999-09-24

    KENNEDY SPACE CENTER, FLA. -- At the Shuttle Landing Facility, egrets along the runway take flight as the orbiter Columbia leaves Kennedy Space Center on the back of a Boeing 747 Shuttle Carrier Aircraft on a ferry flight to Palmdale, Calif. Columbia, the oldest of four orbiters in NASA's fleet, will undergo extensive inspections and modifications in Boeing's Orbiter Assembly Facility during a nine-month orbiter maintenance down period (OMDP), the second in its history. Orbiters are periodically removed from flight operations for an OMDP. Columbia's first was in 1994. Along with more than 100 modifications on the vehicle, Columbia will be the second orbiter to be outfitted with the multifunctional electronic display system, or "glass cockpit." Columbia is expected to return to KSC in July 2000

  4. KSC-99pp1142

    NASA Image and Video Library

    1999-09-24

    KENNEDY SPACE CENTER, FLA. -- The Boeing 747 Shuttle Carrier Aircraft, with the orbiter Columbia strapped to its back, waits at the Shuttle Landing Facility for clear weather to take off for its final destination, Palmdale, Calif. The oldest of four orbiters in NASA's fleet, Columbia is being ferried to Palmdale to undergo extensive inspections and modifications in Boeing's Orbiter Assembly Facility. The nine-month orbiter maintenance down period (OMDP) is the second in Columbia's history. Orbiters are periodically removed from flight operations for an OMDP. Columbia's first was in 1994. Along with more than 100 modifications on the vehicle, Columbia will be the second orbiter to be outfitted with the multifunctional electronic display system, or "glass cockpit." Columbia is expected to return to KSC in July 2000

  5. KSC-99pp1141

    NASA Image and Video Library

    1999-09-24

    KENNEDY SPACE CENTER, FLA. -- The Boeing 747 Shuttle Carrier Aircraft is cast in morning shadows as it backs away from the Mate/Demate Device with the orbiter Columbia strapped to its back. The oldest of four orbiters in NASA's fleet, Columbia is being ferried to Palmdale, Calif., where it will undergo extensive inspections and modifications in Boeing's Orbiter Assembly Facility. The nine-month orbiter maintenance down period (OMDP) is the second in Columbia's history. Orbiters are periodically removed from flight operations for an OMDP. Columbia's first was in 1994. Along with more than 100 modifications on the vehicle, Columbia will be the second orbiter to be outfitted with the multifunctional electronic display system, or "glass cockpit." Columbia is expected to return to KSC in July 2000

  6. KENNEDY SPACE CENTER, FLA. - This bird's-eye view of a high bay in the Orbiter Processing Facility (OPF) shows the open payload bay of Space Shuttle Discovery surrounded by the standard platforms and equipment required to process a Space Shuttle orbiter. The high bay is 197 feet (60 meters) long, 150 feet (46 meters) wide, 95 feet (29 meters) high, and encompasses a 29,000-square-foot (2,694-meter) area. The 30-ton (27-metric-ton) bridge crane (yellow device, right) has a hook height of approximately 66 feet (20 meters). Platforms, a main access bridge, and two rolling bridges with trucks provide access to various parts of the orbiter. In addition to routine servicing and checkout, the inspections and modifications made to enhance Discovery's performance and upgrade its systems were performed in the OPF during its recently completed Orbiter Major Modification (OMM) period.

    NASA Image and Video Library

    2003-09-02

    KENNEDY SPACE CENTER, FLA. - This bird's-eye view of a high bay in the Orbiter Processing Facility (OPF) shows the open payload bay of Space Shuttle Discovery surrounded by the standard platforms and equipment required to process a Space Shuttle orbiter. The high bay is 197 feet (60 meters) long, 150 feet (46 meters) wide, 95 feet (29 meters) high, and encompasses a 29,000-square-foot (2,694-meter) area. The 30-ton (27-metric-ton) bridge crane (yellow device, right) has a hook height of approximately 66 feet (20 meters). Platforms, a main access bridge, and two rolling bridges with trucks provide access to various parts of the orbiter. In addition to routine servicing and checkout, the inspections and modifications made to enhance Discovery's performance and upgrade its systems were performed in the OPF during its recently completed Orbiter Major Modification (OMM) period.

  7. The Lunar Orbital Prospector

    NASA Technical Reports Server (NTRS)

    Redd, Frank J.; Cantrell, James N.; Mccurdy, Greg

    1992-01-01

    The establishment of lunar bases will not end the need for remote sensing of the lunar surface by orbiting platforms. Human and robotic surface exploration will necessarily be limited to some proximate distance from the support base. Near real-time, high-resolution, global characterization of the lunar surface by orbiting sensing systems will continue to be essential to the understanding of the Moon's geophysical structure and the location of exploitable minerals and deposits of raw materials. The Lunar Orbital Prospector (LOP) is an orbiting sensing platform capable of supporting a variety of modular sensing packages. Serviced by a lunar-based shuttle, the LOP will permit the exchange of instrument packages to meet evolving mission needs. The ability to recover, modify, and rotate sensing packages allows their reuse in varying combinations. Combining this flexibility with robust orbit modification capabilities and near real-time telemetry links provides considerable system responsiveness. Maintenance and modification of the LOP orbit are accomplished through use of an onboard propulsion system that burns lunar-supplied oxygen and aluminum. The relatively low performance of such a system is more than compensated for by the elimination of the need for Earth-supplied propellants. The LOP concept envisions a continuous expansion of capability through the incorporation of new instrument technologies and the addition of platforms.

  8. KSC-03pd0262

    NASA Image and Video Library

    2003-02-04

    KENNEDY SPACE CENTER, FLA. -- United Space Alliance (USA) technicians install thermal protection system tiles on Space Shuttle Discovery. Discovery is undergoing its Orbiter Major Modification Period, a regularly scheduled structural inspection and modification downtime, which began in September 2002. .

  9. Separated Fringe Packet Observations with the CHARA Array. I. Methods and New Orbits for χ Draconis, HD 184467, and HD 198084

    NASA Astrophysics Data System (ADS)

    Farrington, C. D.; ten Brummelaar, T. A.; Mason, B. D.; Hartkopf, W. I.; McAlister, H. A.; Raghavan, D.; Turner, N. H.; Sturmann, L.; Sturmann, J.; Ridgway, S. T.

    2010-06-01

    We present the modification of the orbits of χ Draconis and HD 184467, and a completely new orbit for HD 198084, including data taken at the Center for High Angular Resolution Astronomy (CHARA) Array. These data were obtained using a modification of the technique of separated fringe packets (SFPs). The accuracy of the SFP data surpasses that of data taken by speckle, but the technique is much more time and labor intensive. Additionally, using SFPs with the CHARA Array, it is possible to obtain separations below the detection range of speckle interferometry (>=30 mas) above the range in "classic" long-baseline interferometry where fringes from a binary overlap are no longer separated (<=10 mas). Using spectroscopic binary systems with published speckle orbits, we are able to test our new measurements against their ephemerides to calibrate the method as well as produce entirely new orbits for systems with no current astrometric observations.

  10. Flight Experiment Demonstration System (FEDS): Mathematical specification

    NASA Technical Reports Server (NTRS)

    Shank, D. E.

    1984-01-01

    Computational models for the flight experiment demonstration system (FEDS) code 580 were developed. The FEDS is a modification of the automated orbit determination system which was developed during 1981 and 1982. The purpose of FEDS is to demonstrate, in a simulated spacecraft environment, the feasibility of using microprocessors to perform onboard orbit determination with limited ground support.

  11. KENNEDY SPACE CENTER, FLA. - On a tour of the Orbiter Processing Facility, Center Director Jim Kennedy (center) and Deputy Director Woodrow Whitlow Jr. (far left) look at the external tank door corrosion work being done on Endeavour. Next to Whitlow is Bruce Buckingham, assistant to the deputy director. Providing information, at right, are Orbiter Airframe Engineering ground area manager, and Tom Roberts, Airframe Engineering System specialist, both with United Space Alliance; and Joy Huff, with KSC Space Shuttle Processing. Endeavour is in its Orbiter Major Modification period, which began in December 2003.

    NASA Image and Video Library

    2004-02-25

    KENNEDY SPACE CENTER, FLA. - On a tour of the Orbiter Processing Facility, Center Director Jim Kennedy (center) and Deputy Director Woodrow Whitlow Jr. (far left) look at the external tank door corrosion work being done on Endeavour. Next to Whitlow is Bruce Buckingham, assistant to the deputy director. Providing information, at right, are Orbiter Airframe Engineering ground area manager, and Tom Roberts, Airframe Engineering System specialist, both with United Space Alliance; and Joy Huff, with KSC Space Shuttle Processing. Endeavour is in its Orbiter Major Modification period, which began in December 2003.

  12. KENNEDY SPACE CENTER, FLA. - On a tour of the Orbiter Processing Facility, Center Director Jim Kennedy (center) and Deputy Director Woodrow Whitlow Jr. (far left) look at the external tank door corrosion work being done on Endeavour. Next to Whitlow is Bruce Buckingham, assistant to the deputy director. Providing information, at right, are Kathy Laufenberg, Orbiter Airframe Engineering ground area manager, and Tom Roberts, Airframe Engineering System specialist, both with United Space Alliance; and Joy Huff, with Space Shuttle Processing. Endeavour is in its Orbiter Major Modification period, which began in December 2003.

    NASA Image and Video Library

    2004-02-25

    KENNEDY SPACE CENTER, FLA. - On a tour of the Orbiter Processing Facility, Center Director Jim Kennedy (center) and Deputy Director Woodrow Whitlow Jr. (far left) look at the external tank door corrosion work being done on Endeavour. Next to Whitlow is Bruce Buckingham, assistant to the deputy director. Providing information, at right, are Kathy Laufenberg, Orbiter Airframe Engineering ground area manager, and Tom Roberts, Airframe Engineering System specialist, both with United Space Alliance; and Joy Huff, with Space Shuttle Processing. Endeavour is in its Orbiter Major Modification period, which began in December 2003.

  13. Entry dynamics of space shuttle orbiter with lateral-directional stability and control uncertainties at supersonic and hypersonic speeds

    NASA Technical Reports Server (NTRS)

    Stone, H. W.; Powell, R. W.

    1977-01-01

    A six-degree-of-freedom simulation analysis was conducted to examine the effects of the lateral-directional static aerodynamic stability and control uncertainties on the performance of the automatic (no manual inputs) entry-guidance and control systems of the space shuttle orbiter. To establish the acceptable boundaries of the uncertainties, the static aerodynamic characteristics were varied either by applying a multiplier to the aerodynamic parameter or by adding an increment. Control-system modifications were identified that decrease the sensitivity to off-nominal aerodynamics. With these modifications, the acceptable aerodynamic boundaries were determined.

  14. Systematic Propulsion Optimization Tools (SPOT)

    NASA Technical Reports Server (NTRS)

    Bower, Mark; Celestian, John

    1992-01-01

    This paper describes a computer program written by senior-level Mechanical Engineering students at the University of Alabama in Huntsville which is capable of optimizing user-defined delivery systems for carrying payloads into orbit. The custom propulsion system is designed by the user through the input of configuration, payload, and orbital parameters. The primary advantages of the software, called Systematic Propulsion Optimization Tools (SPOT), are a user-friendly interface and a modular FORTRAN 77 code designed for ease of modification. The optimization of variables in an orbital delivery system is of critical concern in the propulsion environment. The mass of the overall system must be minimized within the maximum stress, force, and pressure constraints. SPOT utilizes the Design Optimization Tools (DOT) program for the optimization techniques. The SPOT program is divided into a main program and five modules: aerodynamic losses, orbital parameters, liquid engines, solid engines, and nozzles. The program is designed to be upgraded easily and expanded to meet specific user needs. A user's manual and a programmer's manual are currently being developed to facilitate implementation and modification.

  15. MSFC Skylab electrical power systems mission evaluation

    NASA Technical Reports Server (NTRS)

    Woosley, A. P.

    1974-01-01

    The design, development, and operation of the Skylab electrical power system are discussed. The electrical systems for the airlock module of the orbital workshop and the Apollo telescope mount are described. Skylab is considered an integral laboratory, however, both cluster and module hardware distinct sections are included. Significant concept and requirement evolution, testing, and modifications resulting from tests are briefly summarized to aid in understanding the launch configuration description and the procedures and performance discussed for in-orbit operation. Specific problems encountered during Skylab orbital missions are analyzed.

  16. KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, one of two orbital maneuvering system (OMS) pods removed from Endeavour is lowered toward a transporter. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

    NASA Image and Video Library

    2003-09-05

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, one of two orbital maneuvering system (OMS) pods removed from Endeavour is lowered toward a transporter. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

  17. KENNEDY SPACE CENTER, FLA. - Technicians in the Orbiter Processing Facility oversee removal of one of two orbital maneuvering system (OMS) pods from Endeavour. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

    NASA Image and Video Library

    2003-09-05

    KENNEDY SPACE CENTER, FLA. - Technicians in the Orbiter Processing Facility oversee removal of one of two orbital maneuvering system (OMS) pods from Endeavour. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

  18. KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility prepare to remove one of two orbital maneuvering system (OMS) pods from Endeavour. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

    NASA Image and Video Library

    2003-09-05

    KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility prepare to remove one of two orbital maneuvering system (OMS) pods from Endeavour. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

  19. KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, one of two orbital maneuvering system (OMS) pods removed from Endeavour is suspended overhead. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

    NASA Image and Video Library

    2003-09-05

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, one of two orbital maneuvering system (OMS) pods removed from Endeavour is suspended overhead. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

  20. KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, one of two orbital maneuvering system (OMS) pods removed from Endeavour is lowered onto a transporter. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

    NASA Image and Video Library

    2003-09-05

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, one of two orbital maneuvering system (OMS) pods removed from Endeavour is lowered onto a transporter. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

  1. Tests and comparisons of gravity models.

    NASA Technical Reports Server (NTRS)

    Marsh, J. G.; Douglas, B. C.

    1971-01-01

    Optical observations of the GEOS satellites were used to obtain orbital solutions with different sets of geopotential coefficients. The solutions were compared before and after modification to high order terms (necessary because of resonance) and were then analyzed by comparing subsequent observations with predicted trajectories. The most important source of error in orbit determination and prediction for the GEOS satellites is the effect of resonance found in most published sets of geopotential coefficients. Modifications to the sets yield greatly improved orbits in most cases. The results of these comparisons suggest that with the best optical tracking systems and gravity models, satellite position error due to gravity model uncertainty can reach 50-100 m during a heavily observed 5-6 day orbital arc. If resonant coefficients are estimated, the uncertainty is reduced considerably.

  2. IGOS improvements for Seasat

    NASA Technical Reports Server (NTRS)

    Warmke, J. M.

    1979-01-01

    Modifications to Battelle's Interactive Graphics Orbit Selection (IGOS) computer program to assist in the planning and evaluation of the Seasat-A Scatterometer System (SASS) flight program were studied. To meet the planning needs of the LaRC Seasat-A Scatterometer team, the following features/modifications were implemented in IGOS: (1) display and specification of time increments in orbital passes represented by the cross-hatching of ground swaths; (2) addition of pass number annotations on the horizontal axis of the STPLNG and STPTOD plots; (3) modification of the sensor model to include more than two swaths associated with a single sensor to approximate the SASS cell pattern; (4) inclusion of down range and cross-track swath geometry to display the characteristic skewed SASS pattern; (5) addition of a swath schedule to allow the display of the SASS mode changes and to calibrate gaps; and (6) development of a set of commands to generate the detailed swath data from sensor characteristics and orbit/earth motion.

  3. Space Shuttle orbiter modifications to support Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Segert, Randall; Lichtenfels, Allyson

    1992-01-01

    The Space Shuttle will be the primary vehicle to support the launch, assembly, and maintenance of the Space Station Freedom (SSF). In order to accommodate this function, the Space Shuttle orbiter will require significant modifications. These modifications are currently in development in the Space Shuttle Program. The requirements for the planned modifications to the Space Shuttle orbiter are dependent on the design of the SSF. Therefore, extensive coordination is required with the Space Station Freedom Program (SSFP) in order to identify requirements and resolve integration issues. This paper describes the modifications to the Space Shuttle orbiter required to support SSF assembly and operations.

  4. Sun Series program for the REEDA System. [predicting orbital lifetime using sunspot values

    NASA Technical Reports Server (NTRS)

    Shankle, R. W.

    1980-01-01

    Modifications made to data bases and to four programs in a series of computer programs (Sun Series) which run on the REEDA HP minicomputer system to aid NASA's solar activity predictions used in orbital life time predictions are described. These programs utilize various mathematical smoothing technique and perform statistical and graphical analysis of various solar activity data bases residing on the REEDA System.

  5. Detail view of the lower portion of the vertical stabilizer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail view of the lower portion of the vertical stabilizer of the Orbiter Discovery. The section below the rudder, often referred to as the "stinger", is used to house the orbiter drag chute assembly. The system consisted of a mortar deployed pilot chute, the main drag chute, a controller assembly and an attach/jettison mechanism. This system was a modification to the original design of the Orbiter Discovery to safely reduce the roll to stop distance without adversely affecting the vehicle handling qualities. This view was taken from a service platform in the Orbiter Processing Facility at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  6. Symmetric and asymmetric exchange stiffnesses of transition-metal thin film interfaces in external electric field

    NASA Astrophysics Data System (ADS)

    Nakamura, K.; Pradipto, A.-M.; Akiyama, T.; Ito, T.; Oguchi, T.; Weinert, M.

    2018-07-01

    The electric-field induced modifications of the symmetric and asymmetric exchange stiffness constants for the prototypical transition-metal system of a Co monolayer on Pt(111) are determined from first-principles calculated total energy differences of spin-spiral states with oppositely rotating magnetizations in the presence of both the external field and spin-orbit coupling. The trend underlying the modifications is shown to be linked to orbital magnetism. The results demonstrate that an electric field may be a promising approach to manipulate macroscopically magnetic textures.

  7. Orbiter Auxiliary Power Unit Flight Support Plan

    NASA Technical Reports Server (NTRS)

    Guirl, Robert; Munroe, James; Scott, Walter

    1990-01-01

    This paper discussed the development of an integrated Orbiter Auxiliary Power Unit (APU) and Improved APU (IAPU) Flight Suuport Plan. The plan identifies hardware requirements for continued support of flight activities for the Space Shuttle Orbiter fleet. Each Orbiter vehicle has three APUs that provide power to the hydraulic system for flight control surface actuation, engine gimbaling, landing gear deployment, braking, and steering. The APUs contain hardware that has been found over the course of development and flight history to have operating time and on-vehicle exposure time limits. These APUs will be replaced by IAPUs with enhanced operating lives on a vehicle-by-vehicle basis during scheduled Orbiter modification periods. This Flight Support Plan is used by program management, engineering, logistics, contracts, and procurement groups to establish optimum use of available hardware and replacement quantities and delivery requirements for APUs until vehicle modifications and incorporation of IAPUs. Changes to the flight manifest and program delays are evaluated relative to their impact on hardware availability.

  8. New osculating orbits for 110 comets and analysis of original orbits for 200 comets

    NASA Technical Reports Server (NTRS)

    Marsden, B. G.; Sekanina, Z.; Everhart, E.

    1978-01-01

    Osculating orbits are presented for 110 nearly parabolic comets. Combining these with selected orbit determinations from other sources, a total of 200 orbits are considered where the available observations yield a result of very good (first-class) or good (second-class) quality. For each of these, the original and future orbits (referred to the barycenter of the solar system) are calculated. The Oort effect (a tendency for original reciprocal semimajor axis values to range from zero to +100 millionths per AU) is clearly seen among the first-class orbits but not among the second-class orbits. Modifications in original reciprocal semimajor axis values due to the effects of nongravitational forces are considered.

  9. The PROPEL Electrodynamic Tether Demonstration Mission

    NASA Technical Reports Server (NTRS)

    Bilen, Sven G.; Johnson, C. Les; Wiegmann, Bruce M.; Alexander, Leslie; Gilchrist, Brian E.; Hoyt, Robert P.; Elder, Craig H.; Fuhrhop, Keith P.; Scadera, Michael

    2012-01-01

    The PROPEL ("Propulsion using Electrodynamics") mission will demonstrate the operation of an electrodynamic tether propulsion system in low Earth orbit and advance its technology readiness level for multiple applications. The PROPEL mission has two primary objectives: first, to demonstrate the capability of electrodynamic tether technology to provide robust and safe, near-propellantless propulsion for orbit-raising, de-orbit, plane change, and station keeping, as well as to perform orbital power harvesting and formation flight; and, second, to fully characterize and validate the performance of an integrated electrodynamic tether propulsion system, qualifying it for infusion into future multiple satellite platforms and missions with minimal modification. This paper provides an overview of the PROPEL system and design reference missions; mission goals and required measurements; and ongoing PROPEL mission design efforts.

  10. Replacement of Atlantis', OV-104's, right orbital maneuvering system pod

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Atlantis', Orbiter Vehicle (OV) 104's, right orbital maneuvering system (OMS) pod (RP01) is placed in a checkout cell at Kennedy Space Center's (KSC's) Hypergolic Maintenance Facility (HMF). Technicians steady OMS mounted on ground handling cart as third technician, standing on ladder, secures support frame. At the HMF, a group of specially-equipped buildings in the KSC Industrial Area, the OMS pods are undergoing extensive processing, including removal of certain components that will undergo modification at vendor facilities prior to the Shuttle's return to flight. The OMS pods are bolted to the aft fuselage of the orbiter and contain the engines and thrusters used to maneuver the spaceship in orbit. View provided by KSC with alternate number KSC-87PC-93.

  11. Topex Microwave Radiometer thermal control - Post-system-test modifications and on-orbit performance

    NASA Technical Reports Server (NTRS)

    Lin, Edward I.

    1993-01-01

    The Topex Microwave Radiometer has had an excellent thermal performance since launch. The instrument, however, went through a hardware modification right before launch to correct for a thermal design inadequacy that was uncovered during the spacecraft thermal vacuum test. This paper reports on how the initially obscure problem was tracked down, and how the thermal models were revised, validated, and utilized to investigate the solution options and guide the hardware modification decisions. Details related to test data interpretation, analytical uncertainties, and model-prediction vs. test-data correlation, are documented. Instrument/spacecraft interface issues, where the problem originated and where in general pitfalls abound, are dealt with specifically. Finally, on-orbit thermal performance data are presented, which exhibit good agreement with flight predictions, and lessons learned are discussed.

  12. KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, KSC employee Gene Peavler works in the wheel area on the orbiter Discovery. The vehicle has undergone Orbiter Major Modifications in the past year. Discovery is scheduled to fly on mission STS-121 to the International Space Station.

    NASA Image and Video Library

    2003-12-09

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, KSC employee Gene Peavler works in the wheel area on the orbiter Discovery. The vehicle has undergone Orbiter Major Modifications in the past year. Discovery is scheduled to fly on mission STS-121 to the International Space Station.

  13. KSC-07pd0158

    NASA Image and Video Library

    2007-01-23

    KENNEDY SPACE CENTER, FLA. -- The right-hand orbital maneuvering system pod is being delivered to Orbiter Processing Facility bay 2 for installation on the orbiter Endeavour. The orbital maneuvering system/reaction control system left- and right-hand pods are attached to the upper aft fuselage left and right sides. Each pod is fabricated primarily of graphite epoxy composite and aluminum. Each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. The orbiter is being prepared for its first launch in just over four years. The vehicle has undergone an extensive modification period, including the addition of all of the return-to-flight safety upgrades added to both Discovery and Atlantis. Endeavour is targeted for launch of mission STS-118 on June 28. Photo credit: NASA/Kim Shiflett

  14. KSC-07pd0159

    NASA Image and Video Library

    2007-01-23

    KENNEDY SPACE CENTER, FLA. -- The right-hand orbital maneuvering system pod is driven past the Vehicle Assembly Building on its way to Orbiter Processing Facility bay 2 for installation on the orbiter Endeavour. The orbital maneuvering system/reaction control system left- and right-hand pods are attached to the upper aft fuselage left and right sides. Each pod is fabricated primarily of graphite epoxy composite and aluminum. Each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. The orbiter is being prepared for its first launch in just over four years. The vehicle has undergone an extensive modification period, including the addition of all of the return-to-flight safety upgrades added to both Discovery and Atlantis. Endeavour is targeted for launch of mission STS-118 on June 28. Photo credit: NASA/Kim Shiflett

  15. Comet/Asteroid Protection System (CAPS): A Space-Based System Concept for Revolutionizing Earth Protection and Utilization of Near-Earth Objects

    NASA Technical Reports Server (NTRS)

    Mazanek, Daniel D.; Roithmayr, Carlos M.; Antol, Jeffrey; Kay-Bunnell, Linda; Werner, Martin R.; Park, Sang-Young; Kumar, Renjith R.

    2002-01-01

    There exists an infrequent, but significant hazard to life and property due to impacting asteroids and comets. There is currently no specific search for long-period comets, smaller near-Earth asteroids, or smaller short-period comets. These objects represent a threat with potentially little or no warning time using conventional ground-based telescopes. These planetary bodies also represent a significant resource for commercial exploitation, long-term sustained space exploration, and scientific research. The Comet/Asteroid Protection System (CAPS) would expand the current detection effort to include long-period comets, as well as small asteroids and short-period comets capable of regional destruction. A space-based detection system, despite being more costly and complex than Earth-based initiatives, is the most promising way of expanding the range of detectable objects, and surveying the entire celestial sky on a regular basis. CAPS is a future spacebased system concept that provides permanent, continuous asteroid and comet monitoring, and rapid, controlled modification of the orbital trajectories of selected bodies. CAPS would provide an orbit modification system capable of diverting kilometer class objects, and modifying the orbits of smaller asteroids for impact defense and resource utilization. This paper provides a summary of CAPS and discusses several key areas and technologies that are being investigated.

  16. Bill Parsons with Discovery Processing Team

    NASA Image and Video Library

    2003-08-29

    Mark McGee (right) shows the bead blasting completed on the rudder speed brake on orbiter Discovery to Shuttle Program Manager Bill Parsons (center). McGee is manager, Orbiter Processing Facility, with United Space Alliance. At left is Mark Nappi, deputy associate program manager, ground operations, USA. The work was part of Orbiter Major Modifications (OMM) that were recently completed on Discovery. The OMM work ranged from wiring, control panels and black boxes to gaseous and fluid systems tubing and components. These systems were deserviced, disassembled, inspected, modified, reassembled, checked out and reserviced, as were most other systems onboard. The work included the installation of the Multifunction Electronic Display Subsystem (MEDS) - a state-of-the-art “glass cockpit.”

  17. Analysis of space shuttle orbiter entry dynamics from Mach 10 to Mach 2.5 with the November 1976 flight control system

    NASA Technical Reports Server (NTRS)

    Powell, R. W.; Stone, H. W.

    1980-01-01

    A six-degree-of-freedom simulation analysis was performed for the space shuttle orbiter entry from Mach 10 to Mach 2.5 with realistic off-nominal conditions using the flight control system referred to as the November 1976 Integrated Digital Autopilot. The off-nominal conditions included: (1) aerodynamic uncertainties in extrapolating from wind tunnel of flight characteristics, (2) error in deriving angle of attack from onboard instrumentation, (3) failure of two of the four reaction control-system thrusters on each side (design specification), and (4) lateral center-of-gravity offset. Many combinations of these off-nominal conditions resulted in a loss of the orbiter. Control-system modifications were identified to prevent this possibility.

  18. Applying the OTV to lunar logistics

    NASA Technical Reports Server (NTRS)

    Willcockson, W. H.

    1988-01-01

    The Orbit Transfer Vehicle (OTV), representing the next generation of upper stages, has recently been studied in a Phase A concept definition study managed by NASA's Marshall Space Flight Center. The vehicle has been previously defined as strictly an orbit-to-orbit type transfer device. Recently its application to the task of lunar surface logistics was investigated. Transfer options to the surface were considered which included direct transfer, and transfer via lunar orbit as well as the L1 libration point. The subsystem modifications required to enable lunar landings were established for the following elements: aerobrake, main propulsion system, landing legs, primary structure, and avionics. It is concluded that the majority of the basic systems required for efficient transfer to the lunar surface are already contained in the OTV.

  19. NDE of the space shuttle orbiter thermal protection system: Phase 2 final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tow, D.M.; Barna, B.A.; Rodriguez, J.G.

    1989-03-01

    Research continued on the development of a nondestructive evaluation technique for inspecting bonds on the space shuttle orbiter thermal protection system tiles. The approach taken uses a noncontacting laser sensor to measure the vibrational response of bonded tiles to acoustical excitation. Laboratory work concentrated on investigating the dynamic response of ''acreage'' tiles, i.e., tiles covering the underside of the orbiter, all approximately square. A number of promising unbond signatures have been identified in the time and frequency domain response. Field tests were conducted to study environmental effects on the techniques being developed. The ambient motion of the orbiter was foundmore » to be larger than expected, necessitating modifications to current techniques. 2 refs., 21 figs., 1 tab.« less

  20. Space Operations Center system analysis study extension. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The analysis fo Space Operations Center (SOC) systems is summarized. Design considerations, configurations of the manned orbital space station, planned operational and research missions, and subsystem tradeoffs are considered. Integration into the space transportation system is discussed. A modular design concept permitting growth of the SOC as its functions are expanded is described. Additional considerations are special requirements for habitat modules, design modifications needed to operate in geosynchronous orbits, and use of the external tank for cryogenic propellant storage or as a pressurized hangar. A cost summary is presented.

  1. Shuttle orbiter Ku-band radar/communications system design evaluation

    NASA Technical Reports Server (NTRS)

    Dodds, J.; Holmes, J.; Huth, G. K.; Iwasaki, R.; Maronde, R.; Polydoros, A.; Weber, C.; Broad, P.

    1980-01-01

    Tasks performed in an examination and critique of a Ku-band radar communications system for the shuttle orbiter are reported. Topics cover: (1) Ku-band high gain antenna/widebeam horn design evaluation; (2) evaluation of the Ku-band SPA and EA-1 LRU software; (3) system test evaluation; (4) critical design review and development test evaluation; (5) Ku-band bent pipe channel performance evaluation; (6) Ku-band LRU interchangeability analysis; and (7) deliverable test equipment evaluation. Where discrepancies were found, modifications and improvements to the Ku-band system and the associated test procedures are suggested.

  2. Comet/Asteroid Protection System (CAPS): Preliminary Space-Based Concept and Study Results

    NASA Technical Reports Server (NTRS)

    Mazanek, Daniel D.; Roithmayr, Carlos M.; Antol, Jeffrey; Park, Sang-Young; Koons, Robert H.; Bremer, James C.; Murphy, Douglas G.; Hoffman, James A.; Kumar, Renjith R.; Seywald, Hans

    2005-01-01

    There exists an infrequent, but significant hazard to life and property due to impacting asteroids and comets. There is currently no specific search for long-period comets, smaller near-Earth asteroids, or smaller short-period comets. These objects represent a threat with potentially little or no warning time using conventional ground-based telescopes. These planetary bodies also represent a significant resource for commercial exploitation, long-term sustained space exploration, and scientific research. The Comet/Asteroid Protection System (CAPS) is a future space-based system concept that provides permanent, continuous asteroid and comet monitoring, and rapid, controlled modification of the orbital trajectories of selected bodies. CAPS would expand the current detection effort to include long-period comets, as well as small asteroids and short-period comets capable of regional destruction. A space-based detection system, despite being more costly and complex than Earth-based initiatives, is the most promising way of expanding the range of detectable objects, and surveying the entire celestial sky on a regular basis. CAPS would provide an orbit modification system capable of diverting kilometer class objects, and modifying the orbits of smaller asteroids for impact defense and resource utilization. This Technical Memorandum provides a compilation of key related topics and analyses performed during the CAPS study, which was performed under the Revolutionary Aerospace Systems Concepts (RASC) program, and discusses technologies that could enable the implementation of this future system.

  3. International Space Station (ISS) Carbon Dioxide Removal Assembly (CDRA) Desiccant/Adsorbent Bed (DAB) Orbital Replacement Unit (ORU) Redesign

    NASA Technical Reports Server (NTRS)

    Reysa, Richard P.; Lumpkin, John P.; Sherif, Dian El; Kay, Robert; Williams, David E.

    2007-01-01

    The Carbon Dioxide Removal Assembly (CDRA) is a part of the International Space Station (ISS) Environmental Control and Life Support (ECLS) system. The CDRA provides carbon dioxide (CO2) removal from the ISS on-orbit modules. Currently, the CDRA is the secondary removal system on the ISS, with the primary system being the Russian Vozdukh. Within the CDRA are two desiccant/adsorbent beds (DAB), which perform the carbon dioxide removal function. The DAB adsorbent containment approach required improvements with respect to adsorbent containment. These improvements were implemented through a redesign program and have been implemented on units returning from orbit. This paper presents a DAB design modification implementation description, a hardware performance comparison between the unmodified and modified DAB configurations, and a description of the modified DAB hardware implementation into the on-orbit CDRA.

  4. ESTL tracking and data relay satellite /TDRSS/ simulation system

    NASA Technical Reports Server (NTRS)

    Kapell, M. H.

    1980-01-01

    The Tracking Data Relay Satellite System (TDRSS) provides single access forward and return communication links with the Shuttle/Orbiter via S-band and Ku-band frequency bands. The ESTL (Electronic Systems Test Laboratory) at Lyndon B. Johnson Space Center (JSC) utilizes a TDRS satellite simulator and critical TDRS ground hardware for test operations. To accomplish Orbiter/TDRSS relay communications performance testing in the ESTL, a satellite simulator was developed which met the specification requirements of the TDRSS channels utilized by the Orbiter. Actual TDRSS ground hardware unique to the Orbiter communication interfaces was procured from individual vendors, integrated in the ESTL, and interfaced via a data bus for control and status monitoring. This paper discusses the satellite simulation hardware in terms of early development and subsequent modifications. The TDRS ground hardware configuration and the complex computer interface requirements are reviewed. Also, special test hardware such as a radio frequency interference test generator is discussed.

  5. Extrasolar planets.

    PubMed

    Lissauer, J J; Marcy, G W; Ida, S

    2000-11-07

    The first known extrasolar planet in orbit around a Sun-like star was discovered in 1995. This object, as well as over two dozen subsequently detected extrasolar planets, were all identified by observing periodic variations of the Doppler shift of light emitted by the stars to which they are bound. All of these extrasolar planets are more massive than Saturn is, and most are more massive than Jupiter. All orbit closer to their stars than do the giant planets in our Solar System, and most of those that do not orbit closer to their star than Mercury is to the Sun travel on highly elliptical paths. Prevailing theories of star and planet formation, which are based on observations of the Solar System and of young stars and their environments, predict that planets should form in orbit about most single stars. However, these models require some modifications to explain the properties of the observed extrasolar planetary systems.

  6. Extrasolar planets

    PubMed Central

    Lissauer, Jack J.; Marcy, Geoffrey W.; Ida, Shigeru

    2000-01-01

    The first known extrasolar planet in orbit around a Sun-like star was discovered in 1995. This object, as well as over two dozen subsequently detected extrasolar planets, were all identified by observing periodic variations of the Doppler shift of light emitted by the stars to which they are bound. All of these extrasolar planets are more massive than Saturn is, and most are more massive than Jupiter. All orbit closer to their stars than do the giant planets in our Solar System, and most of those that do not orbit closer to their star than Mercury is to the Sun travel on highly elliptical paths. Prevailing theories of star and planet formation, which are based on observations of the Solar System and of young stars and their environments, predict that planets should form in orbit about most single stars. However, these models require some modifications to explain the properties of the observed extrasolar planetary systems. PMID:11035782

  7. Space shuttle phase B extension, volume 1

    NASA Technical Reports Server (NTRS)

    1971-01-01

    In order to define a system which would significantly reduce payload delivery costs, activities were extended to modifications of the reusable space shuttle design concept. Considered were systems using orbiters with external propellant tanks and an interim expendable booster which allowed phased development of the usable orbiter and booster. Analyzed were: Merits of internal and external propellant tanks and the impact of external LH2 compared to L02 and LH2; impact of cargo bay size; impact abort; merit of expendable booster options; and merit of a phased development program. Studies showed that external L02/LH2 and the continued use of the J-2S engine on the orbiter reduced program cost and risk.

  8. British government, industry agree to fund Hotel launcher studies

    NASA Astrophysics Data System (ADS)

    Brown, D. A.

    1986-02-01

    A program status assessment is presented for the horizontal takeoff and landing 'Hotol' single-stage-to-orbit space launcher, for which parallel, two-year airframe and propulsion system proof-of-concept studies have been approved. A two-year initial development program for the airframe would be followed by a four-year development and manufacturing phase that would begin upon the propulsion system concept's successful demonstration. Flight trials could begin in 1996. A number of significant modifications have already been made to the initial design concept, such as to the foreplanes, afterbody, engine intake, and orbital control system.

  9. Entry dynamics of space shuttle orbiter with longitudinal stability and control uncertainties at supersonic and hypersonic speeds

    NASA Technical Reports Server (NTRS)

    Stone, H. W.; Powell, R. W.

    1977-01-01

    A six-degree-of-freedom simulation analysis was conducted to examine the effects of longitudinal static aerodynamic stability and control uncertainties on the performance of the space shuttle orbiter automatic (no manual inputs) entry guidance and control systems. To establish the acceptable boundaries, the static aerodynamic characteristics were varied either by applying a multiplier to the aerodynamic parameter or by adding an increment. With either of two previously identified control system modifications included, the acceptable longitudinal aerodynamic boundaries were determined.

  10. Flight Experiment Demonstration System (FEDS) functional description and interface document

    NASA Technical Reports Server (NTRS)

    Belcher, R. C.; Shank, D. E.

    1984-01-01

    This document presents a functional description of the Flight Experiment Demonstration System (FEDS) and of interfaces between FEDS and external hardware and software. FEDS is a modification of the Automated Orbit Determination System (AODS). FEDS has been developed to support a ground demonstration of microprocessor-based onboard orbit determination. This document provides an overview of the structure and logic of FEDS and details the various operational procedures to build and execute FEDS. It also documents a microprocessor interface between FEDS and a TDRSS user transponder and describes a software simulator of the interface used in the development and system testing of FEDS.

  11. Searching for some natural orbits to observe the double asteroid 2002CE26

    NASA Astrophysics Data System (ADS)

    Mescolotti, Bruna Yukiko Pinheiro Masago; Prado, Antonio Fernando Bertachini de Almeida; Chiaradia, Ana Paula Marins; Gomes, Vivian Martins

    2017-07-01

    Knowledge of the Solar System is increasing with data coming from space missions to small bodies. A mission to those bodies offers some problems, because they have several characteristics that are not well known, like their shapes, sizes and masses. The present research has the goal of searching for trajectories around the double asteroid 2002CE26, a system of Near-Earth Asteroids (NEAs) of the Apollo type. For every trajectory of the spacecraft, the evolution of the distances between the spacecraft and the two bodies that compose the system is crucial, due to its impact in the quality of the observations made from the spacecraft. Furthermore, this study has a first objective of searching for trajectories that make the spacecraft remain as long as possible near the two bodies that compose the asteroid system, without the use of orbital maneuvers. The model used here assumes elliptical orbits for the asteroids. The effect of the solar radiation pressure is also included, since it is a major perturbing force acting in spacecrafts traveling around small bodies. The natural orbits found here are useful for the mission. They can be used individually or combined in several pieces by orbital maneuvers. Another point considered here is the importance of the errors in the estimation of the physical parameters of the bodies. This task is very important, because there are great uncertainties in these values because the measurements are based on observations made from the Earth. It is shown that a variation of those parameters can make very large modifications in the times that the spacecraft remains close to the bodies of the system (called here "observational times"). Those modifications are large enough to make the best trajectories obtained under nominal conditions to be useless under some errors in the physical parameters. So, a search is made to find trajectories that have reasonable observation times for all the assumed error scenarios for the two bodies, because those orbits can be used as initial parking orbits for the spacecraft. We called these orbits "quasi-stable orbits", in the sense that they do not collide with any of the primaries nor travel to large distances from them. From these orbits, it is possible to make better observations of the bodies in any scenario, and a more accurate estimation of their sizes and masses is performed, so giving information to allow for other choices for the orbit of the spacecraft.

  12. KSC-99pp0807

    NASA Image and Video Library

    1999-07-08

    KENNEDY SPACE CENTER, FLA. -- In the cockpit of the orbiter Atlantis, which is in the Orbiter Processing Facility, U.S. Rep. Dave Weldon (right) looks at the newly installed Multifunction Electronic Display Subsystem (MEDS), known as the "glass cockpit." At left is Laural Patrick, a systems engineer with MEDS. Weldon is on the House Science Committee and vice chairman of the Space and Aeronautics Subcommittee. He was in Palmdale, Calif., when Atlantis underwent the modification and he wanted to see the final product. The full-color, flat-panel MEDS upgrade improves crew/orbiter interaction with easy-to-read, graphic portrayals of key flight indicators like attitude display and mach speed. The installation makes Atlantis the most modern orbiter in the fleet and equals the systems on current commercial jet airliners and military aircraft. Atlantis is scheduled to fly on mission STS-101 in early December

  13. Effects on optical systems from interactions with oxygen atoms in low earth orbits

    NASA Technical Reports Server (NTRS)

    Peters, P. N.; Swann, J. T.; Gregory, J. C.

    1986-01-01

    Modifications of material surface properties due to interactions with ambient atomic oxygen have been observed on surfaces facing the orbital direction in low earth orbits. Some effects are very damaging to surface optical properties while some are more subtle and even beneficial. Most combustible materials are heavily etched, and some coatings, such as silver and osmium, are seriously degraded or removed as volatile oxides. The growth of oxide films on metals and semiconductors considered stable in dry air was measured. Material removal, surface roughness, reflectance, and optical densities are reported. Effects of temperature, contamination, and overcoatings are noted.

  14. Effects on optical systems from interactions with oxygen atoms in low earth orbits

    NASA Astrophysics Data System (ADS)

    Peters, P. N.; Swann, J. T.; Gregory, J. C.

    1986-04-01

    Modifications of material surface properties due to interactions with ambient atomic oxygen have been observed on surfaces facing the orbital direction in low earth orbits. Some effects are very damaging to surface optical properties while some are more subtle and even beneficial. Most combustible materials are heavily etched, and some coatings, such as silver and osmium, are seriously degraded or removed as volatile oxides. The growth of oxide films on metals and semiconductors considered stable in dry air was measured. Material removal, surface roughness, reflectance, and optical densities are reported. Effects of temperature, contamination, and overcoatings are noted.

  15. KSC-98pc1164

    NASA Image and Video Library

    1998-09-28

    The orbiter Atlantis is towed away from the Shuttle Landing Facility after returning home from California atop its Shuttle Carrier Aircraft. The orbiter spent 10 months in Palmdale undergoing extensive inspections and modifications in the orbiter processing facility there. The modifications included several upgrades enabling it to support International Space Station missions, such as adding an external airlock for ISS docking missions and installing thinner, lighter thermal protection blankets for weight reduction which will allow it to haul heavier cargo. Atlantis will undergo preparations in the Orbiter Processing Facility at KSC for its planned flight in June 1999

  16. Exoplanet detection. A terrestrial planet in a ~1-AU orbit around one member of a ~15-AU binary.

    PubMed

    Gould, A; Udalski, A; Shin, I-G; Porritt, I; Skowron, J; Han, C; Yee, J C; Kozłowski, S; Choi, J-Y; Poleski, R; Wyrzykowski, Ł; Ulaczyk, K; Pietrukowicz, P; Mróz, P; Szymański, M K; Kubiak, M; Soszyński, I; Pietrzyński, G; Gaudi, B S; Christie, G W; Drummond, J; McCormick, J; Natusch, T; Ngan, H; Tan, T-G; Albrow, M; DePoy, D L; Hwang, K-H; Jung, Y K; Lee, C-U; Park, H; Pogge, R W; Abe, F; Bennett, D P; Bond, I A; Botzler, C S; Freeman, M; Fukui, A; Fukunaga, D; Itow, Y; Koshimoto, N; Larsen, P; Ling, C H; Masuda, K; Matsubara, Y; Muraki, Y; Namba, S; Ohnishi, K; Philpott, L; Rattenbury, N J; Saito, To; Sullivan, D J; Sumi, T; Suzuki, D; Tristram, P J; Tsurumi, N; Wada, K; Yamai, N; Yock, P C M; Yonehara, A; Shvartzvald, Y; Maoz, D; Kaspi, S; Friedmann, M

    2014-07-04

    Using gravitational microlensing, we detected a cold terrestrial planet orbiting one member of a binary star system. The planet has low mass (twice Earth's) and lies projected at ~0.8 astronomical units (AU) from its host star, about the distance between Earth and the Sun. However, the planet's temperature is much lower, <60 Kelvin, because the host star is only 0.10 to 0.15 solar masses and therefore more than 400 times less luminous than the Sun. The host itself orbits a slightly more massive companion with projected separation of 10 to 15 AU. This detection is consistent with such systems being very common. Straightforward modification of current microlensing search strategies could increase sensitivity to planets in binary systems. With more detections, such binary-star planetary systems could constrain models of planet formation and evolution. Copyright © 2014, American Association for the Advancement of Science.

  17. U.S. Rep. Dave Weldon looks at the U.S. Lab Destiny in the SSPF.

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In the cockpit of the orbiter Atlantis, which is in the Orbiter Processing Facility, Laural Patrick (left), a systems engineer with MEDS, points out a feature of the newly installed Multifunction Electronic Display Subsystem (MEDS), known as the 'glass cockpit,' to U.S. Rep. Dave Weldon. The congressman is on the House Science Committee and vice chairman of the Space and Aeronautics Subcommittee. He was in Palmdale, Calif., when Atlantis underwent the modification and he wanted to see the final product. The full-color, flat-panel MEDS upgrade improves crew/orbiter interaction with easy-to-read, graphic portrayals of key flight indicators like attitude display and mach speed. The installation makes Atlantis the most modern orbiter in the fleet and equals the systems on current commercial jet airliners and military aircraft. Atlantis is scheduled to fly on mission STS- 101 in early December.

  18. KSC-98pc1165

    NASA Image and Video Library

    1998-09-28

    The orbiter Atlantis, being towed from the Shuttle Landing Facility, is reflected in waters from the Banana Creek next to the towway. The orbiter spent 10 months in Palmdale, CA, undergoing extensive inspections and modifications in the orbiter processing facility there. The modifications included several upgrades enabling it to support International Space Station missions, such as adding an external airlock for ISS docking missions and installing thinner, lighter thermal protection blankets for weight reduction which will allow it to haul heavier cargo. Atlantis will undergo preparations in the Orbiter Processing Facility at KSC for its planned flight in June 1999

  19. Lunar Cube Transfer Trajectory Options

    NASA Technical Reports Server (NTRS)

    Folta, David; Dichmann, Donald James; Clark, Pamela E.; Haapala, Amanda; Howell, Kathleen

    2015-01-01

    Numerous Earth-Moon trajectory and lunar orbit options are available for Cubesat missions. Given the limited Cubesat injection infrastructure, transfer trajectories are contingent upon the modification of an initial condition of the injected or deployed orbit. Additionally, these transfers can be restricted by the selection or designs of Cubesat subsystems such as propulsion or communication. Nonetheless, many trajectory options can b e considered which have a wide range of transfer duration, fuel requirements, and final destinations. Our investigation of potential trajectories highlights several options including deployment from low Earth orbit (LEO) geostationary transfer orbits (GTO) and higher energy direct lunar transfer and the use of longer duration Earth-Moon dynamical systems. For missions with an intended lunar orbit, much of the design process is spent optimizing a ballistic capture while other science locations such as Sun-Earth libration or heliocentric orbits may simply require a reduced Delta-V imparted at a convenient location along the trajectory.

  20. Lunar Cube Transfer Trajectory Options

    NASA Technical Reports Server (NTRS)

    Folta, David; Dichmann, Donald J.; Clark, Pamela; Haapala, Amanda; Howell, Kathleen

    2015-01-01

    Numerous Earth-Moon trajectory and lunar orbit options are available for Cubesat missions. Given the limited Cubesat injection infrastructure, transfer trajectories are contingent upon the modification of an initial condition of the injected or deployed orbit. Additionally, these transfers can be restricted by the selection or designs of Cubesat subsystems such as propulsion or communication. Nonetheless, many trajectory options can be considered which have a wide range of transfer durations, fuel requirements, and final destinations. Our investigation of potential trajectories highlights several options including deployment from low Earth orbit (LEO), geostationary transfer orbits (GTO), and higher energy direct lunar transfers and the use of longer duration Earth-Moon dynamical systems. For missions with an intended lunar orbit, much of the design process is spent optimizing a ballistic capture while other science locations such as Sun-Earth libration or heliocentric orbits may simply require a reduced Delta-V imparted at a convenient location along the trajectory.

  1. Space Shuttle Orbiter trimmed center-of-gravity extension study. Volume 4: Effects of configuration modifications on the aerodynamic characteristics of the 139B orbiter at Mach 20.3

    NASA Technical Reports Server (NTRS)

    Scallion, W. I.; Stone, D. R.

    1978-01-01

    Force tests were conducted at Mach 20.3 to determine the effect of several forebody, wing-fillet, and canard modifications on the hypersonic trim capability of a 139B Space Shuttle Orbiter model. Force and moment data were obtained at angles of attack of 10 deg to 54 deg at zero sideslip angle and at a Reynolds number of 1,900,000 based on body length. The results indicated that wing-fillet and canard modifications would increase the allowable forward trimmed center-of-gravity capability by as much as 3.0 percent of the body length.

  2. Orbital spacecraft consumables resupply

    NASA Technical Reports Server (NTRS)

    Dominick, Sam M.; Eberhardt, Ralph N.; Tracey, Thomas R.

    1988-01-01

    The capability to replenish spacecraft, satellites, and laboratories on-orbit with consumable fluids provides significant increases in their cost and operational effectiveness. Tanker systems to perform on-orbit fluid resupply must be flexible enough to operate from the Space Transportation System (STS), Space Station, or the Orbital Maneuvering Vehicle (OMV), and to accommodate launch from both the Shuttle and Expendable Launch Vehicles (ELV's). Resupply systems for storable monopropellant hydrazine and bipropellants, and water have been developed. These studies have concluded that designing tankers capable of launch on both the Shuttle and ELV's was feasible and desirable. Design modifications and interfaces for an ELV launch of the tanker systems were identified. Additionally, it was determined that modularization of the tanker subsystems was necessary to provide the most versatile tanker and most efficient approach for use at the Space Station. The need to develop an automatic umbilical mating mechanism, capable of performing both docking and coupler mating functions was identified. Preliminary requirements for such a mechanism were defined. The study resulted in a modular tanker capable of resupplying monopropellants, bipropellants, and water with a single design.

  3. Numerical computation of complex multi-body Navier-Stokes flows with applications for the integrated Space Shuttle launch vehicle

    NASA Technical Reports Server (NTRS)

    Chan, William M.

    1993-01-01

    An enhanced grid system for the Space Shuttle Orbiter was built by integrating CAD definitions from several sources and then generating the surface and volume grids. The new grid system contains geometric components not modeled previously plus significant enhancements on geometry that has been modeled in the old grid system. The new orbiter grids were then integrated with new grids for the rest of the launch vehicle. Enhancements were made to the hyperbolic grid generator HYPGEN and new tools for grid projection, manipulation, and modification, Cartesian box grid and far field grid generation and post-processing of flow solver data were developed.

  4. International Space Station United States Orbital Segment Oxygen Generation System On-Orbit Operational Experience

    NASA Technical Reports Server (NTRS)

    Erickson, Robert J.; Howe, John, Jr.; Kulp, Galen W.; VanKeuren, Steven P.

    2008-01-01

    The International Space Station (ISS) United States Orbital Segment (USOS) Oxygen Generation System (OGS) was originally intended to be installed in ISS Node 3. The OGS rack delivery was accelerated, and it was launched to ISS in July of 2006 and installed in the US Laboratory Module. Various modification kits were installed to provide its interfaces, and the OGS was first activated in July of 2007 for 15 hours, In October of 2007 it was again activated for 76 hours with varied production rates and day/night cycling. Operational time in each instance was limited by the quantity of feedwater in a Payload Water Reservoir (PWR) bag. Feedwater will be provided by PWR bag until the USOS Water Recovery System (WRS) is delivered to SS in fall of 2008. This paper will discuss operating experience and characteristics of the OGS, as well as operational issues and their resolution.

  5. The control of satellites with microgravity constraints: The COMET Control System

    NASA Astrophysics Data System (ADS)

    Grossman, Walter; Freesland, Douglas

    1994-05-01

    The COMET attitude determination and control system, using inverse dynamics and a novel torque distribution/momentum management technique, has shown great flexibility, performance, and robustness. Three-axis control with two wheels is an inherent consequence of inverse dynamics control which allows for reduction in spacecraft weight and cost, or alternatively, provides a simple means of failure-redundancy for three-wheel spacecraft. The control system, without modification, has continued to perform well in spite of large changes in spacecraft mass properties and mission orbit altitude that have occurred during development. This flexibility has obviated imposition of early stringent ADACS design constraints and has greatly reduced commonly incurred ADACS modification costs and delay associated with program maturation.

  6. The control of satellites with microgravity constraints: The COMET Control System

    NASA Technical Reports Server (NTRS)

    Grossman, Walter; Freesland, Douglas

    1994-01-01

    The COMET attitude determination and control system, using inverse dynamics and a novel torque distribution/momentum management technique, has shown great flexibility, performance, and robustness. Three-axis control with two wheels is an inherent consequence of inverse dynamics control which allows for reduction in spacecraft weight and cost, or alternatively, provides a simple means of failure-redundancy for three-wheel spacecraft. The control system, without modification, has continued to perform well in spite of large changes in spacecraft mass properties and mission orbit altitude that have occurred during development. This flexibility has obviated imposition of early stringent ADACS design constraints and has greatly reduced commonly incurred ADACS modification costs and delay associated with program maturation.

  7. Survey of Enabling Technologies for CAPS

    NASA Technical Reports Server (NTRS)

    Antol, Jeffrey; Mazanek, Daniel D.; Koons, Robert H.

    2005-01-01

    The enabling technologies required for the development of a viable Comet/Asteroid Protection System (CAPS) can be divided into two principal areas: detection and deflection/orbit modification. With the proper funding levels, many of the technologies needed to support a CAPS architecture could be achievable within the next 15 to 20 years. In fact, many advanced detection technologies are currently in development for future in-space telescope systems such as the James Webb Space Telescope (JWST), formerly known as the Next Generation Space Telescope. It is anticipated that many of the JWST technologies would be available for application for CAPS detection concepts. Deflection/orbit modification technologies are also currently being studied as part of advanced power and propulsion research. However, many of these technologies, such as extremely high-output power systems, advanced propulsion, heat rejection, and directed energy systems, would likely be farther term in availability than many of the detection technologies. Discussed subsequently is a preliminary examination of the main technologies that have been identified as being essential to providing the element functionality defined during the CAPS conceptual study. The detailed requirements for many of the technology areas are still unknown, and many additional technologies will be identified as future in-depth studies are conducted in this area.

  8. KSC-98pc1166

    NASA Image and Video Library

    1998-09-28

    The orbiter Atlantis, being towed from the Shuttle Landing Facility toward the Vehicle Assembly Building (VAB) , intersects the morning sun's rays. In the background, to the right of the VAB, are the Orbiter Processing Facility 1 and 2. Atlantis spent 10 months in Palmdale, CA, undergoing extensive inspections and modifications in the orbiter processing facility there. The modifications included several upgrades enabling it to support International Space Station missions, such as adding an external airlock for ISS docking missions and installing thinner, lighter thermal protection blankets for weight reduction which will allow it to haul heavier cargo. Atlantis will undergo preparations at KSC in Orbiter Processing Facility 2 for its planned flight in June 1999

  9. Pioneer spacecraft operation at low and high spin rates

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The feasibility of executing major changes upward or downward from the nominal spin rate for which the Pioneer F&G spacecraft was designed was investigated along with the extent of system and subsystem modifications required to implement these mode changes in future spacecraft evolving from the baseline Pioneer F and G. Results of a previous study are re-examined and updated for an extended range of spin rate variations for missions that include outer planet orbiters, outer planet flyby and outer planet probe delivery. However, in the interest of design simplicity and cost economy, major modifications of the baseline Pioneer system and subsystem concept were avoided.

  10. KSC-99pp0808

    NASA Image and Video Library

    1999-07-08

    KENNEDY SPACE CENTER, FLA. -- In the cockpit of the orbiter Atlantis, which is in the Orbiter Processing Facility, U.S. Rep. Dave Weldon looks at the newly installed Multifunction Electronic Display Subsystem (MEDS), known as the "glass cockpit." Weldon is on the House Science Committee and vice chairman of the Space and Aeronautics Subcommittee. He was in Palmdale, Calif., when Atlantis underwent the modification and he wanted to see the final product. The full-color, flat-panel MEDS upgrade improves crew/orbiter interaction with easy-to-read, graphic portrayals of key flight indicators like attitude display and mach speed. The installation makes Atlantis the most modern orbiter in the fleet and equals the systems on current commercial jet airliners and military aircraft. Atlantis is scheduled to fly on mission STS-101 in early December

  11. Mars Sample Return Using Solar Sail Propulsion

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Macdonald, Malcolm; Mcinnes, Colin; Percy, Tom

    2012-01-01

    Many Mars Sample Return (MSR) architecture studies have been conducted over the years. A key element of them is the Earth Return Stage (ERS) whose objective is to obtain the sample from the Mars Ascent Vehicle (MAV) and return it safely to the surface of the Earth. ERS designs predominantly use chemical propulsion [1], incurring a significant launch mass penalty due to the low specific impulse of such systems coupled with the launch mass sensitivity to returned mass. It is proposed to use solar sail propulsion for the ERS, providing a high (effective) specific impulse propulsion system in the final stage of the multi-stage system. By doing so to the launch mass of the orbiter mission can be significantly reduced and hence potentially decreasing mission cost. Further, solar sailing offers a unique set of non-Keplerian low thrust trajectories that may enable modifications to the current approach to designing the Earth Entry Vehicle by potentially reducing the Earth arrival velocity. This modification will further decrease the mass of the orbiter system. Solar sail propulsion uses sunlight to propel vehicles through space by reflecting solar photons from a large, mirror-like surface made of a lightweight, reflective material. The continuous photonic pressure provides propellantless thrust to conduct orbital maneuvering and plane changes more efficiently than conventional chemical propulsion. Because the Sun supplies the necessary propulsive energy, solar sails require no onboard propellant, thus reducing system mass. This technology is currently at TRL 7/8 as demonstrated by the 2010 flight of the Japanese Aerospace Exploration Agency, JAXA, IKAROS mission. [2

  12. Shuttle/GPSPAC experimentation study

    NASA Technical Reports Server (NTRS)

    Moses, J.; Flack, J. F.

    1977-01-01

    The utilization is discussed of the GPSPAC, which is presently being developed to be used on the low altitude host vehicle (LAHV), for possible use in the shuttle avionics system to evaluate shuttle/GPS navigation performance. Analysis and tradeoffs of the shuttle/GPS link, shuttle signal interface requirements, oscillator tradeoffs and GPSPAC mechanical modifications for shuttle are included. Only the on-orbit utilization of GPSPAC for the shuttle is discussed. Other phases are briefly touched upon. Recommendations are provided for using the present GPSPAC and the changes required to perform shuttle on-orbit navigation.

  13. Beam orbit simulation in the central region of the RIKEN AVF cyclotron

    NASA Astrophysics Data System (ADS)

    Toprek, Dragan; Goto, Akira; Yano, Yasushige

    1999-04-01

    This paper describes the modification design of the central region for h=2 mode of acceleration in the RIKEN AVF cyclotron. we made a small modification to the electrode shape in the central region for optimization of the beam transmission. The central region is equipped with an axial injection system. The spiral type inflector is used for axial injection. The electric field distribution in the inflector and in four acceleration gaps has been numerically calculated from an electric potential map produced by the program RELAX3D. The magnetic field is measured. The geometry of the central region has been tested with the computations of orbits carried out by means of the computer code CYCLONE. The optical properties of the spiral inflector and the central region are studied by using the program CASINO and CYCLONE, respectively. We have also made an effort to minimize the inflector fringe field effects using the RELAX3D program.

  14. Evaluation of electrostatic charge effects on the data processing system and the orbiter communication and tracking receivers

    NASA Technical Reports Server (NTRS)

    Lawton, R. M.

    1975-01-01

    An analysis of radiated interference test results obtained from frictionally charged Orbiter TPS tile was presented. The tests included the measurement of noise pick-up by Orbiter S-band, L-band, C-band, and Ku-band antennas located beneath the tiles in a manner simulating their installation on Orbiter. In addition, the radiated field characteristics resulting from the static discharge was determined. The results are analyzed as to their effect on data bus equipment and on Orbiter Communications and Tracking (C&T) receivers. It was concluded that the radiated interference should have no effect on MDM's. However the CPU, IOP and PMU enclosures require some minor modification to assure immunity from P-static interference. Orbiter antenna tests indicate that the S-band receiver should not be affected by P-static noise. The TACAN and Radar Altimeter performance appears to be adequate but with a small margin. MSBLS performance is uncertain because laboratory instrumentation cannot approach the MSBLS sensitivity.

  15. RS-34 Phoenix In-Space Propulsion System Applied to Active Debris Removal Mission

    NASA Technical Reports Server (NTRS)

    Esther, Elizabeth A.; Burnside, Christopher G.

    2014-01-01

    In-space propulsion is a high percentage of the cost when considering Active Debris Removal mission. For this reason it is desired to research if existing designs with slight modification would meet mission requirements to aid in reducing cost of the overall mission. Such a system capable of rendezvous, close proximity operations, and de-orbit of Envisat class resident space objects has been identified in the existing RS-34 Phoenix. RS-34 propulsion system is a remaining asset from the de-commissioned United States Air Force Peacekeeper program; specifically the pressure-fed storable bi-propellant Stage IV Post Boost Propulsion System. The National Aeronautics and Space Administration (NASA) Marshall Space Flight Center (MSFC) gained experience with the RS-34 propulsion system on the successful Ares I-X flight test program flown in the Ares I-X Roll control system (RoCS). The heritage hardware proved extremely robust and reliable and sparked interest for further utilization on other potential in-space applications. Subsequently, MSFC has obtained permission from the USAF to obtain all the remaining RS-34 stages for re-use opportunities. The MSFC Advanced Concepts Office (ACO) was commissioned to lead a study for evaluation of the Rocketdyne produced RS-34 propulsion system as it applies to an active debris removal design reference mission for resident space object targets including Envisat. Originally designed, the RS-34 Phoenix provided in-space six-degrees-of freedom operational maneuvering to deploy payloads at multiple orbital locations. The RS-34 Concept Study lead by sought to further understand application for a similar orbital debris design reference mission to provide propulsive capability for rendezvous, close proximity operations to support the capture phase of the mission, and deorbit of single or multiple large class resident space objects. Multiple configurations varying the degree of modification were identified to trade for dry mass optimization and propellant load. The results of the RS-34 Phoenix Concept Study show that the system is technically sufficient to successfully support all of the missions to rendezvous, capture, and de-orbit targets including Envisat and Hubble Space Telescope. The results and benefits of the RS-34 Orbital Debris Application Concept Study are presented in this paper.

  16. Assessment of SEPS solar array technology for orbital service module application

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Work performed in the following assessment areas on the SEPS solar array is reported: (1) requirements definition, (2) electrical design evaluation, (3) mechanical design evaluation, and (4) design modification analysis. General overall assessment conclusions are summarized. There are no known serious design limitations involved in the implementation of the recommended design modifications. A section of orbiter and array engineering drawings is included.

  17. Node 3 Relocation Environmental Control and Life Support System Modification Kit Verification and Updated Status

    NASA Technical Reports Server (NTRS)

    Williams, David E.; Spector, Lawrence N.

    2009-01-01

    Node 1 (Unity) flew to International Space Station (ISS) on Flight 2A. Node 1 was the first module of the United States On-Orbit Segment (USOS) launched to ISS. The Node 1 ISS Environmental Control and Life Support (ECLS) design featured limited ECLS capability. The main purpose of Node 1 was to provide internal storage by providing four stowage rack locations within the module and to allow docking of multiple modules and a truss segment to it. The ECLS subsystems inside Node 1 were routed through the element prior to launch to allow for easy integration of the attached future elements, particularly the Habitation Module which was planned to be located at the nadir docking port of Node 1. After Node 1 was on-orbit, the Program decided not to launch the Habitation Module and instead, to replace it with Node 3 (Tranquility). In 2007, the Program became concerned with a potential Russian docking port approach issue for the Russian FGB nadir docking port after Node 3 is attached to Node 1. To solve this concern the Program decided to relocate Node 3 from Node 1 nadir to Node 1 port. To support the movement of Node 3 the Program decided to build a modification kit for Node 1, an on-orbit feedthrough leak test device, and new vestibule jumpers to support the ECLS part of the relocation. This paper provides a design overview of the modification kit, a summary of the Node 1 ECLS re-verification to support the Node 3 relocation from Node 1 nadir to Node 1 port, and a status of the ECLS modification kit installation into Node 1.

  18. Node 3 Relocation Environmental Control and Life Support System Modification Kit Verification and Updated Status

    NASA Technical Reports Server (NTRS)

    Williams, David E.; Spector Lawrence N.

    2010-01-01

    Node 1 (Unity) flew to International Space Station (ISS) on Flight 2A. Node 1 was the first module of the United States On-Orbit Segment (USOS) launched to ISS. The Node 1 ISS Environmental Control and Life Support (ECLS) design featured limited ECLS capability. The main purpose of Node 1 was to provide internal storage by providing four stowage rack locations within the module and to allow docking of multiple modules and a truss segment to it. The ECLS subsystems inside Node 1 were routed through the element prior to launch to allow for easy integration of the attached future elements, particularly the Habitation Module which was planned to be located at the nadir docking port of Node 1. After Node I was on-orbit, the Program decided not to launch the Habitation Module and instead, to replace it with Node 3 (Tranquility). In 2007, the Program became concerned with a potential Russian docking port approach issue for the Russian FGB nadir docking port after Node 3 is attached to Node 1. To solve this concern the Program decided to relocate Node 3 from Node I nadir to Node 1 port. To support the movement of Node 3 the Program decided to build a modification kit for Node 1, an on-orbit feedthrough leak test device, and new vestibule jumpers to support the ECLS part of the relocation. This paper provides a design overview of the modification kit for Node 1, a summary of the Node 1 ECLS re-verification to support the Node 3 relocation from Node 1 nadir to Node 1 port, and a status of the ECLS modification kit installation into Node 1.

  19. Attractive manifold-based adaptive solar attitude control of satellites in elliptic orbits

    NASA Astrophysics Data System (ADS)

    Lee, Keum W.; Singh, Sahjendra N.

    2011-01-01

    The paper presents a novel noncertainty-equivalent adaptive (NCEA) control system for the pitch attitude control of satellites in elliptic orbits using solar radiation pressure (SRP). The satellite is equipped with two identical solar flaps to produce control moments. The adaptive law is based on the attractive manifold design using filtered signals for synthesis, which is a modification of the immersion and invariance (I&I) method. The control system has a modular controller-estimator structure and has separate tunable gains. A special feature of this NCEA law is that the trajectories of the satellite converge to a manifold in an extended state space, and the adaptive law recovers the performance of a deterministic controller. This recovery of performance cannot be obtained with certainty-equivalent adaptive (CEA) laws. Simulation results are presented which show that the NCEA law accomplishes precise attitude control of the satellite in an elliptic orbit, despite large parameter uncertainties.

  20. Single launch lunar habitat derived from an NSTS external tank

    NASA Technical Reports Server (NTRS)

    King, Charles B.; Butterfield, Ansel J.; Hypes, Warren D.; Nealy, John E.; Simonsen, Lisa C.

    1990-01-01

    A concept for using the spent external tank from a National Space Transportation System (NSTS) to derive a lunar habitat is described. The external tank is carried into low Earth orbit where the oxygen tank-intertank subassembly is separated from the hydrogen tank, berthed to Space Station Freedom and the subassembly outfitted as a 12-person lunar habitat using extravehicular activity (EVA) and intravehicular activity (IVA). A single launch of the NSTS orbiter can place the external tank in LEO, provide orbiter astronauts for disassembly of the external tank, and transport the required subsystem hardware for outfitting the lunar habitat. An estimate of the astronauts' EVA and IVA is provided. The liquid oxygen intertank modifications utilize existing structures and openings for man access without compromising the structural integrity of the tank. The modifications include installation of living quarters, instrumentation, and an airlock. Feasibility studies of the following additional systems include micrometeoroid and radiation protection, thermal control, environmental control and life support, and propulsion. The converted lunar habitat is designed for unmanned transport and autonomous soft landing on the lunar surface without need for site preparation. Lunar regolith is used to fill the micrometeoroid shield volume for radiation protection using a conveyer. The lunar habitat concept is considered to be feasible by the year 2000 with the concurrent development of a space transfer vehicle and a lunar lander for crew changeover and resupply.

  1. Decentralized Formation Flying Control in a Multiple-Team Hierarchy

    NASA Technical Reports Server (NTRS)

    Mueller, Joseph .; Thomas, Stephanie J.

    2005-01-01

    This paper presents the prototype of a system that addresses these objectives-a decentralized guidance and control system that is distributed across spacecraft using a multiple-team framework. The objective is to divide large clusters into teams of manageable size, so that the communication and computational demands driven by N decentralized units are related to the number of satellites in a team rather than the entire cluster. The system is designed to provide a high-level of autonomy, to support clusters with large numbers of satellites, to enable the number of spacecraft in the cluster to change post-launch, and to provide for on-orbit software modification. The distributed guidance and control system will be implemented in an object-oriented style using MANTA (Messaging Architecture for Networking and Threaded Applications). In this architecture, tasks may be remotely added, removed or replaced post-launch to increase mission flexibility and robustness. This built-in adaptability will allow software modifications to be made on-orbit in a robust manner. The prototype system, which is implemented in MATLAB, emulates the object-oriented and message-passing features of the MANTA software. In this paper, the multiple-team organization of the cluster is described, and the modular software architecture is presented. The relative dynamics in eccentric reference orbits is reviewed, and families of periodic, relative trajectories are identified, expressed as sets of static geometric parameters. The guidance law design is presented, and an example reconfiguration scenario is used to illustrate the distributed process of assigning geometric goals to the cluster. Next, a decentralized maneuver planning approach is presented that utilizes linear-programming methods to enact reconfiguration and coarse formation keeping maneuvers. Finally, a method for performing online collision avoidance is discussed, and an example is provided to gauge its performance.

  2. On the false lock behavior of polarity-type Costas loops with Manchester coded input. [for Space Shuttle Orbiter communication

    NASA Technical Reports Server (NTRS)

    Simon, M. K.

    1977-01-01

    A modification of a Costas loop is described, and the false lock behavior of this system is studied. The modified Costas loop hard limits the output of the in-phase channel, replaces the analog multiplier with a chopper-type device, and is equipped with single-pole arm filters in the loop. The false lock behavior associated with the use of Manchester coded data is investigated; the results can be applied to the assessment of the false lock margin on the Ku-band uplink to the Space Shuttle Orbiter through the TURSS.

  3. Three-Dimensional Eyeball and Orbit Volume Modification After LeFort III Midface Distraction.

    PubMed

    Smektala, Tomasz; Nysjö, Johan; Thor, Andreas; Homik, Aleksandra; Sporniak-Tutak, Katarzyna; Safranow, Krzysztof; Dowgierd, Krzysztof; Olszewski, Raphael

    2015-07-01

    The aim of our study was to evaluate orbital volume modification with LeFort III midface distraction in patients with craniosynostosis and its influence on eyeball volume and axial diameter modification. Orbital volume was assessed by the semiautomatic segmentation method based on deformable surface models and on 3-dimensional (3D) interaction with haptics. The eyeball volumes and diameters were automatically calculated after manual segmentation of computed tomographic scans with 3D slicer software. The mean, minimal, and maximal differences as well as the standard deviation and intraclass correlation coefficient (ICC) for intraobserver and interobserver measurements reliability were calculated. The Wilcoxon signed rank test was used to compare measured values before and after surgery. P < 0.05 was considered statistically significant. Intraobserver and interobserver ICC for haptic-aided semiautomatic orbital volume measurements were 0.98 and 0.99, respectively. The intraobserver and interobserver ICC values for manual segmentation of the eyeball volume were 0.87 and 0.86, respectively. The orbital volume increased significantly after surgery: 30.32% (mean, 5.96  mL) for the left orbit and 31.04% (mean, 6.31  mL) for the right orbit. The mean increase in eyeball volume was 12.3%. The mean increases in the eyeball axial dimensions were 7.3%, 9.3%, and 4.4% for the X-, Y-, and Z-axes, respectively. The Wilcoxon signed rank test showed that preoperative and postoperative eyeball volumes, as well as the diameters along the X- and Y-axes, were statistically significant. Midface distraction in patients with syndromic craniostenosis results in a significant increase (P < 0.05) in the orbit and eyeball volumes. The 2 methods (haptic-aided semiautomatic segmentation and manual 3D slicer segmentation) are reproducible techniques for orbit and eyeball volume measurements.

  4. Texture Modification of the Shuttle Landing Facility Runway at Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Daugherty, Robert H.; Yager, Thomas J.

    1997-01-01

    This paper describes the test procedures and the criteria used in selecting an effective runway-surface-texture modification at the Kennedy Space Center (KSC) Shuttle Landing Facility (SLF) to reduce Orbiter tire wear. The new runway surface may ultimately result in an increase of allowable crosswinds for launch and landing operations. The modification allows launch and landing operations in 20-knot crosswinds, if desired. This 5-knot increase over the previous 15-knot limit drastically increases landing safety and the ability to make on-time launches to support missions in which Space Station rendezvous are planned. The paper presents the results of an initial (1988) texture modification to reduce tire spin-up wear and then describes a series of tests that use an instrumented ground-test vehicle to compare tire friction and wear characteristics, at small scale, of proposed texture modifications placed into the SLF runway surface itself. Based on these tests, three candidate surfaces were chosen to be tested at full-scale by using a highly modified and instrumented transport aircraft capable of duplicating full Orbiter landing profiles. The full-scale Orbiter tire testing revealed that tire wear could be reduced approximately by half with either of two candidates. The texture-modification technique using a Humble Equipment Company Skidabrader(trademark) shotpeening machine proved to be highly effective, and the entire SLF runway surface was modified in September 1994. The extensive testing and evaluation effort that preceded the selection of this particular surface-texture-modification technique is described herein.

  5. Orbital Atherectomy in the Renal Artery: A New Frontier for an Emerging Technology?

    PubMed

    Valle, Javier A; Armstrong, Ehrin J; Waldo, Stephen W

    2017-01-01

    Orbital atherectomy has been developed as a method to modify calcified plaque in the peripheral vasculature, with extensive experience and data supporting its use in infrainguinal peripheral arterial disease. However, calcific atherosclerotic disease occurs in other vascular beds and may benefit from the application of this technology. In this case report, we describe the first reported use of orbital atherectomy in a renal artery. A 55-year-old male with severe drug-refractory hypertension was found to have renal artery stenosis, with severe calcification of the right renal artery. Orbital atherectomy was utilized for initial plaque modification, and he underwent stenting of the renal artery lesion with an excellent angiographic and clinical result at follow-up. In conclusion, orbital atherectomy is a safe and effective means of plaque modification for severely calcified lesions. The safe and effective use of orbital atherectomy in the renal vasculature suggests an opportunity for ongoing evaluation into expanded roles for this technology beyond the coronary and lower-extremity arterial beds.

  6. Mars Geoscience Orbiter and Lunar Geoscience Orbiter

    NASA Technical Reports Server (NTRS)

    Fuldner, W. V.; Kaskiewicz, P. F.

    1983-01-01

    The feasibility of using the AE/DE Earth orbiting spacecraft design for the LGO and/or MGO missions was determined. Configurations were developed and subsystems analysis was carried out to optimize the suitability of the spacecraft to the missions. The primary conclusion is that the basic AE/DE spacecraft can readily be applied to the LGO mission with relatively minor, low risk modifications. The MGO mission poses a somewhat more complex problem, primarily due to the overall maneuvering hydrazine budget and power requirements of the sensors and their desired duty cycle. These considerations dictate a modification (scaling up) of the structure to support mission requirements.

  7. Identification and status of design improvements to the NASA Shuttle EMU for International Space Station application.

    PubMed

    Wilde, R C; McBarron, J W; Faszcza, J J

    1997-06-01

    To meet the significant increase in EVA demand to support assembly and operations of the International Space Station (ISS), NASA and industry have improved the current Shuttle Extravehicular Mobility Unit (EMU), or "space suit", configuration to meet the unique and specific requirements of an orbital-based system. The current Shuttle EMU was designed to be maintained and serviced on the ground between frequent Shuttle flights. ISS will require the EMUs to meet increased EVAs out of the Shuttle Orbiter and to remain on orbit for up to 180 days without need for regular return to Earth for scheduled maintenance or refurbishment. Ongoing Shuttle EMU improvements have increased reliability, operational life and performance while minimizing ground and on-orbit maintenance cost and expendable inventory. Modifications to both the anthropomorphic mobility elements of the Space Suit Assembly (SSA) as well as to the Primary Life Support System (PLSS) are identified and discussed. This paper also addresses the status of on-going Shuttle EMU improvements and summarizes the approach for increasing interoperability of the U.S. and Russian space suits to be utilized aboard the ISS.

  8. NASA's Evolution to Ka-Band Space Communications for Near-Earth Spacecraft

    NASA Technical Reports Server (NTRS)

    McCarthy, Kevin; Stocklin, Frank; Geldzahler, Barry; Friedman, Daniel; Celeste, Peter

    2010-01-01

    This slide presentation reviews the exploration of NASA using a Ka-band system for spacecraft communications in Near-Earth orbits. The reasons for changing to Ka-band are the higher data rates, and the current (X-band spectrum) is becoming crowded. This will require some modification to the current ground station antennas systems. The results of a Request for Information (RFI) are discussed, and the recommended solution is reviewed.

  9. Analysis of the Yukawa gravitational potential in f (R ) gravity. II. Relativistic periastron advance

    NASA Astrophysics Data System (ADS)

    De Laurentis, Mariafelicia; De Martino, Ivan; Lazkoz, Ruth

    2018-05-01

    Alternative theories of gravity may serve to overcome several shortcomings of the standard cosmological model but, in their weak field limit, general relativity must be recovered so as to match the tight constraints at the Solar System scale. Therefore, testing such alternative models at scales of stellar systems could give a unique opportunity to confirm or rule them out. One of the most straightforward modifications is represented by analytical f (R )-gravity models that introduce a Yukawa-like modification to the Newtonian potential thus modifying the dynamics of particles. Using the geodesics equations, we have illustrated the amplitude of these modifications. First, we have integrated numerically the equations of motion showing the orbital precession of a particle around a massive object. Second, we have computed an analytic expression for the periastron advance of systems having their semimajor axis much shorter than the Yukawa-scale length. Finally, we have extended our results to the case of a binary system composed of two massive objects. Our analysis provides a powerful tool to obtain constraints on the underlying theory of gravity using current and forthcoming data sets.

  10. The Capture of Interstellar Dust: The Pure Poynting-Robertson Case

    NASA Technical Reports Server (NTRS)

    Jackson, A. A.

    2001-01-01

    Ulysses and Galileo spacecraft have discovered interstellar dust particles entering the solar system. In general, particles trajectories not altered by Lorentz forces or radiation pressure should encounter the sun on open orbits. Under Newtonian forces alone these particles return to the interstellar medium. Dissipative forces, such as Poynting Robertson (PR) and corpuscular drag and non-dissipative Lorentz forces can modify open orbits to become closed. In particular, it is possible for the orbits of particles that pass close to the Sun to become closed due to PR drag. Further, solar irradiation will cause modification of the size of the dust particle by evaporation. The combination of these processes gives rise a class of capture orbits and bound orbits with evaporation. Considering only the case of pure PR drag a minimum impact parameter is derived for initial capture by Poynting-Robertson drag. Orbits in the solar radiation field are computed numerically accounting for evaporation with optical and material properties for ideal interstellar particles modeled. The properties of this kind of particle capture are discussed for the Sun but is applicable to other stars.

  11. Shuttle Ku-band and S-band communications implementation study

    NASA Technical Reports Server (NTRS)

    Dodds, J. G.; Huth, G. K.; Nilsen, P. W.; Polydoros, A.; Simon, M. K.; Weber, C. L.

    1980-01-01

    Various aspects of the shuttle orbiter S-band network communication system, the S-band payload communication system, and the Ku-band communication system are considered. A method is proposed for obtaining more accurate S-band antenna patterns of the actual shuttle orbiter vehicle during flight because the preliminary antenna patterns using mock-ups are not realistic that they do not include the effects of additional appendages such as wings and tail structures. The Ku-band communication system is discussed especially the TDRS antenna pointing accuracy with respect to the orbiter and the modifications required and resulting performance characteristics of the convolutionally encoded high data rate return link to maintain bit synchronizer lock on the ground. The TDRS user constraints on data bit clock jitter and data asymmetry on unbalanced QPSK with noisy phase references are included. The S-band payload communication system study is outlined including the advantages and experimental results of a peak regulator design built and evaluated by Axiomatrix for the bent-pipe link versus the existing RMS-type regulator. The nominal sweep rate for the deep-space transponder of 250 Hz/s, and effects of phase noise on the performance of a communication system are analyzed.

  12. Nominal Profile Refinements Report: Target in 120 Nautical Mile Circular Orbit

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The compability of the nominal rendezvous sequence with low target orbits is addressed. It was found that for targets in low earth orbits certain modifications of the nominal sequence are required to achieve a feasible anytime liftoff capability, notably the use of elliptical phasing orbits and the allowance of up to two days for rendezvous under certain phasing conditions.

  13. RS-34 (Peacekeeper Post Boost Propulsion System) Orbital Debris Application Concept Study

    NASA Technical Reports Server (NTRS)

    Esther, Elizabeth A.; Burnside, Christopher G.

    2013-01-01

    The Advanced Concepts Office (ACO) at the NASA Marshall Space Flight Center (MSFC) lead a study to evaluate the Rocketdyne produced RS-34 propulsion system as it applies to an orbital debris removal design reference mission. The existing RS-34 propulsion system is a remaining asset from the de-commissioned United States Air Force Peacekeeper ICBM program; specifically the pressure-fed storable bi-propellant Stage IV Post Boost Propulsion System. MSFC gained experience with the RS-34 propulsion system on the successful Ares I-X flight test program flown in the Ares I-X Roll control system (RoCS). The heritage hardware proved extremely robust and reliable and sparked interest for further utilization on other potential in-space applications. Subsequently, MSFC is working closely with the USAF to obtain all the remaining RS-34 stages for re-use opportunities. Prior to pursuit of securing the hardware, MSFC commissioned the Advanced Concepts Office to understand the capability and potential applications for the RS-34 Phoenix stage as it benefits NASA, DoD, and commercial industry. Originally designed, the RS-34 Phoenix provided in-space six-degrees-of freedom operational maneuvering to deploy multiple payloads at various orbital locations. The RS-34 Concept Study, preceded by a utilization study to understand how the unique capabilities of the RS-34 Phoenix and its application to six candidate missions, sought to further understand application for an orbital debris design reference mission as the orbital debris removal mission was found to closely mimic the heritage RS-34 mission. The RS-34 Orbital Debris Application Concept Study sought to identify multiple configurations varying the degree of modification to trade for dry mass optimization and propellant load for overall capability and evaluation of several candidate missions. The results of the RS-34 Phoenix Utilization Study show that the system is technically sufficient to successfully support all of the missions analyzed. The results and benefits of the RS-34 Orbital Debris Application Concept Study are presented in this paper.

  14. Measurements of the ionospheric reaction to exhaust from dedicated burns of the space shuttle’s orbital maneuvering system engines over Kwajalein

    NASA Astrophysics Data System (ADS)

    Caton, R. G.; Groves, K. M.; Pedersen, T. R.; Hysell, D. L.; Carrano, C. S.; Bernhardt, P. A.; Tsunoda, R. T.; Coster, A. J.

    2009-12-01

    In a continuation of the Shuttle Ionospheric Modification with Pulsed Localized Exhaust (SIMPLEX) experiment, a series of Orbiting Maneuver Subsystem (OMS) engine burns from the space shuttle have been carried out over Kwajalein Atoll in the Republic of the Marshall Islands. Exhaust from the shuttle’s two OMS engines consists of CO, CO2, H2, H20, and N2, each of which interact with the background ionosphere (predominately O+) through charge exchange resulting in electron “holes.” Such interactions have been detected from the ground with radars, optical imagers, and GPS TEC measurements and from space with satellites such as the Communication/Navigation Outage Forecasting System (C/NOFS) in the Shuttle Exhaust Ion Turbulence Experiment (SEITE). In this talk, we present signatures of ionospheric modification resulting from OMS burns during recent shuttle missions observed in incoherent scatter returns on the ARPA Long-range Tracking And Instrumentation Radar (ALTAIR) and in optical data from an All-Sky Imager. GPS TEC measurements are investigated for evidence of depletions resulting from post-burn molecular recombination. Space Shuttle OMS Engine Burn

  15. A single launch lunar habitat derived from an NSTS external tank

    NASA Technical Reports Server (NTRS)

    King, Charles B.; Butterfield, Ansel J.; Hypes, Warren D.; Nealy, John E.; Simonsen, Lisa C.

    1990-01-01

    A concept for using a spent External Tank from the National Space Transportation System (Shuttle) to derive a Lunar habitat is described. The concept is that the External Tank is carried into Low-Earth Orbit (LEO) where the oxygen tank-intertank subassembly is separated from the hydrogen tank, berthed to Space Station Freedom and the subassembly outfitted as a 12-person Lunar habitat using extravehicular activity (EVA) and intravehicular activity (IVA). A single launch of the NSTS Orbiter can place the External Tank in LEO, provide orbiter astronauts for disassembly of the External Tank, and transport the required subsystem hardware for outfitting the Lunar habitat. An estimate of the astronauts' EVA and IVA is provided. The liquid oxygen tank-intertank modifications utilize existing structures and openings for human access without compromising the structural integrity of the tank. The modification includes installation of living quarters, instrumentation, and an air lock. Feasibility studies of the following additional systems include micrometeoroid and radiation protection, thermal-control, environmental-control and life-support, and propulsion. The converted Lunar habitat is designed for unmanned transport and autonomous soft landing on the Lunar surface without need for site preparation. Lunar regolith is used to fill the micrometeoroid shield volume for radiation protection using a conveyor. The Lunar habitat concept is considered to be feasible by the year 2000 with the concurrent development of a space transfer vehicle and a Lunar lander for crew changeover and resupply.

  16. An Advanced Orbiting Systems Approach to Quality of Service in Space-Based Intelligent Communication Networks

    NASA Technical Reports Server (NTRS)

    Riha, Andrew P.

    2005-01-01

    As humans and robotic technologies are deployed in future constellation systems, differing traffic services will arise, e.g., realtime and non-realtime. In order to provide a quality of service framework that would allow humans and robotic technologies to interoperate over a wide and dynamic range of interactions, a method of classifying data as realtime or non-realtime is needed. In our paper, we present an approach that leverages the Consultative Committee for Space Data Systems (CCSDS) Advanced Orbiting Systems (AOS) data link protocol. Specifically, we redefine the AOS Transfer Frame Replay Flag in order to provide an automated store-and-forward approach on a per-service basis for use in the next-generation Interplanetary Network. In addition to addressing the problem of intermittent connectivity and associated services, we propose a follow-on methodology for prioritizing data through further modification of the AOS Transfer Frame.

  17. Comet/Asteroid Protection System: Concept Study Executive Summary

    NASA Technical Reports Server (NTRS)

    Mazanek, Daniel D.

    2005-01-01

    Many of the major issues have been identified for a futuristic capability to protect against impacting comets and asteroids, and a preliminary space-based concept has been envisioned. Some of the basic concept elements, approaches, methodologies, and features have been identified. When contemplating the ability to monitor comets and asteroids continuously, there are many trade-offs between orbiting observatories and detection systems on planetary bodies without an atmosphere. Future orbit modification techniques have the potential for rapid and controlled alteration of NEO orbits, provided that high-power, compatible thermal management systems are developed. Much additional work and analysis are required to identify a final system concept, and many trade studies need to be performed to select the best mix of system capability, reliability, maintainability, and cost. Finally, it is fully appreciated that at the present time space systems are much more costly than terrestrial-based systems. Hopefully, this will change in the future. Regardless, understanding what it would take to defend against a much wider range of the impact threat will foster ideas, innovations, and technologies that could one day enable the development of such a system. This understanding is vital to provide ways of reducing the costs and quantifying the benefits that are achievable with a system like CAPS.

  18. KSC-98pc1167

    NASA Image and Video Library

    1998-09-28

    Seen from behind, the orbiter Atlantis approaches the entrance of Orbiter Processing Facility 2 (OPF-2) where it will undergo preparations for its planned flight in June 1999. Atlantis spent 10 months in Palmdale, CA, undergoing extensive inspections and modifications in the orbiter processing facility there. The modifications included several upgrades enabling it to support International Space Station missions, such as adding an external airlock for ISS docking missions and installing thinner, lighter thermal protection blankets for weight reduction which will allow it to haul heavier cargo. OPF-2 consists of a 2,700-square-meter (29,000 square ft.) high bay. The building measures 29 meters (95 ft). high, 121 meters (397 ft.) long and 71 meters (233 ft.) wide

  19. KSC-98pc1168

    NASA Image and Video Library

    1998-09-28

    Seen from behind, the orbiter Atlantis moves into the Orbiter Processing Facility 2 (OPF-2) where it will undergo preparations for its planned flight in June 1999. Atlantis spent 10 months in Palmdale, CA, undergoing extensive inspections and modifications in the orbiter processing facility there. The modifications included several upgrades enabling it to support International Space Station missions, such as adding an external airlock for ISS docking missions and installing thinner, lighter thermal protection blankets for weight reduction which will allow it to haul heavier cargo. OPF-2 consists of two 2,700-square-meter (29,000 square feet) high bays. It measures 29 meters (95 ft). high, 121 meters (397 ft) long and 71 meters (233 ft) wide

  20. Construction bidding cost of KSC's space shuttle facilities

    NASA Technical Reports Server (NTRS)

    Brown, Joseph Andrew

    1977-01-01

    The bidding cost of the major Space Transportation System facilities constructed under the responsibility of the John F. Kennedy Space Center (KSC) is described and listed. These facilities and Ground Support Equipment (GSE) are necessary for the receiving, assembly, testing, and checkout of the Space Shuttle for launch and landing missions at KSC. The Shuttle launch configuration consists of the Orbiter, the External Tank, and the Solid Rocket Boosters (SRB). The reusable Orbiter and SRB's is the major factor in the program that will result in lowering space travel costs. The new facilities are the Landing Facility; Orbiter Processing Facility; Orbiter Approach and Landing Test Facility (Dryden Test Center, California); Orbiter Mating Devices; Sound Suppression Water System; and Emergency Power System for LC-39. Also, a major factor was to use as much Apollo facilities and hardware as possible to reduce the facilities cost. The alterations to existing Apollo facilities are the VAB modifications; Mobile Launcher Platforms; Launch Complex 39 Pads A and B (which includes a new concept - the Rotary Service Structure), which was featured in ENR, 3 Feb. 1977, 'Hinged Space Truss will Support Shuttle Cargo Room'; Launch Control Center mods; External Tank and SRB Processing and Storage; Fluid Test Complex mods; O&C Spacelab mods; Shuttle mods for Parachute Facility; SRB Recovery and Disassembly Facility at Hangar 'AF'; and an interesting GSE item - the SRB Dewatering Nozzle Plug Sets (Remote Controlled Submarine System) used to inspect and acquire for reuse of SRB's.

  1. AJ26 rocket engine testing news briefing

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Operators at NASA's John C. Stennis Space Center are completing modifications to the E-1 Test Stand to begin testing Aerojet AJ26 rocket engines in early summer of 2010. Modifications include construction of a 27-foot-deep flame deflector trench. The AJ26 rocket engines will be used to power Orbital Sciences Corp.'s Taurus II space vehicles to provide commercial cargo transportation missions to the International Space Station for NASA. Stennis has partnered with Orbital to test all engines for the transport missions.

  2. KSC-95pc586

    NASA Image and Video Library

    1995-04-17

    KENNEDY SPACE CENTER, FLA. - Space Shuttle Main Engine (SSME) No. 2036, the first of the new Block 1 engines to fly, awaits installation into position one of the orbiter Discovery in Orbiter Processing Facility 2 during preparation of the spaceplane for the STS-70 mission. The advanced powerplant features a new high-pressure liquid oxygen turbopump, a two-duct powerhead, a baffleless main injector, a single-coil heat exchanger and start sequence modifications. These modifications are designed to improve both engine performance and safety.

  3. Creating the Deep Space Environment for Testing the James Webb Space Telescope (JWST) at NASA Johnson Space Center's Chamber A

    NASA Technical Reports Server (NTRS)

    Homan, Jonathan L.; Cerimele, Mary P.; Montz, Michael E.; Bachtel, Russell; Speed, John; O'Rear, Patrick

    2013-01-01

    Chamber A is the largest thermal vacuum chamber at the Johnson Space Center and is one of the largest space environment chambers in the world. The chamber is 19.8 m (65 ft) in diameter and 36.6 m (120 ft) tall and is equipped with cryogenic liquid nitrogen panels (shrouds) and gaseous helium shrouds to create a simulated space environment. It was originally designed and built in the mid 1960 s to test the Apollo Command and Service Module and several manned tests were conducted on that spacecraft, contributing to the success of the program. The chamber has been used since that time to test spacecraft active thermal control systems, Shuttle DTO, DOD, and ESA hardware in simulated Low Earth Orbit (LEO) conditions. NASA is now moving from LEO towards exploration of locations with environments approaching those of deep space. Therefore, Chamber A has undergone major modifications to enable it to simulate these deeper space environments. Environmental requirements were driven, and modifications were funded by the James Webb Space Telescope program, and this telescope which will orbit Solar/Earth L2, will be the first test article to benefit from the chamber s new capabilities. To accommodate JWST, the Chamber A high vacuum system has been modernized, additional LN2 shrouds have been installed, the liquid nitrogen system has been modified to remove dependency on electrical power and increase its reliability, a new helium shroud/refrigeration system has been installed to create a colder more stable and uniform heat sink, and the controls have been updated to increase the level of automation and improve operator interfaces. Testing of these major modifications was conducted in August of 2012 and this initial test was very successful, with all major systems exceeding their performance requirements. This paper will outline the changes in overall environmental requirements, discuss the technical design data that was used in the decisions leading to the extensive modifications, and describe the new capabilities of the chamber.

  4. Creating the Deep Space Environment for Testing the James Webb Space Telescope at NASA Johnson Space Center's Chamber A

    NASA Technical Reports Server (NTRS)

    Homan, Jonathan L.; Cerimele, Mary P.; Montz, Michael E.; Bachtel, Russell; Speed, John; O'Rear, Patrick

    2013-01-01

    Chamber A is the largest thermal vacuum chamber at the Johnson Space Center and is one of the largest space environment chambers in the world. The chamber is 19.8 m (65 ft.) in diameter and 36.6 m (120 ft.) tall and is equipped with cryogenic liquid nitrogen panels (shrouds) and gaseous helium shrouds to create a simulated space environment. It was originally designed and built in the mid 1960 s to test the Apollo Command and Service Module and several manned tests were conducted on that spacecraft, contributing to the success of the program. The chamber has been used since that time to test spacecraft active thermal control systems, Shuttle DTO, DOD, and ESA hardware in simulated Low Earth Orbit (LEO) conditions. NASA is now moving from LEO towards exploration of locations with environments approaching those of deep space. Therefore, Chamber A has undergone major modifications to enable it to simulate these deeper space environments. Environmental requirements were driven, and modifications were funded by the James Webb Space Telescope program, and this telescope, which will orbit Solar/Earth L2, will be the first test article to benefit from the chamber s new capabilities. To accommodate JWST, the Chamber A high vacuum system has been modernized, additional LN2 shrouds have been installed, the liquid nitrogen system has been modified to minimize dependency on electrical power and increase its reliability, a new helium shroud/refrigeration system has been installed to create a colder more stable and uniform heat sink, and the controls have been updated to increase the level of automation and improve operator interfaces. Testing of these major modifications was conducted in August of 2012 and this initial test was very successful, with all major systems exceeding their performance requirements. This paper will outline the changes in overall environmental requirements, discuss the technical design data that was used in the decisions leading to the extensive modifications, and describe the new capabilities of the chamber.

  5. Creating the Deep Space Environment for Testing the James Webb Space Telescope at the Johnson Space Center's Chamber A

    NASA Technical Reports Server (NTRS)

    Homan, Jonathan L.; Cerimele, Mary P.; Montz, Michael E.

    2012-01-01

    Chamber A is the largest thermal vacuum chamber at the Johnson Space Center and is one of the largest space environment chambers in the world. The chamber is 19.8 m (65 ft) in diameter and 36.6 m (120 ft) tall and is equipped with cryogenic liquid nitrogen panels (shrouds) and gaseous helium shrouds to create a simulated space environment. It was originally designed and built in the mid 1960's to test the Apollo Command and Service Module and several manned tests were conducted on that spacecraft, contributing to the success of the program. The chamber has been used since that time to test spacecraft active thermal control systems, Shuttle DTO, DOD, and ESA hardware in simulated Low Earth Orbit (LEO) conditions. NASA is now moving from LEO towards exploration of locations with environments approaching those of deep space. Therefore, Chamber A has undergone major modifications to enable it to simulate these deeper space environments. Environmental requirements were driven, and the modifications were funded, by the James Webb Space Telescope program, and this telescope which will orbit Solar/Earth L2, will be the first test article to benefit from the chamber s new capabilities. To accommodate JWST, the Chamber A high vacuum system has been modernized, additional LN2 shrouds have been installed, the liquid nitrogen system has been modified to remove dependency on electrical power and increase its reliability, a new helium shroud/refrigeration system has been installed to create a colder more stable and uniform heat sink and, the controls have been updated to increase the level of automation and improve operator interfaces. Testing of these major modifications was conducted in August 2012 and this initial test was very successful, with all major systems exceeding their performance requirements. This paper will outline the changes in the overall environmental requirements, discuss the technical design data that was used in the decisions leading to the extensive modifications, and describe the new capabilities of the chamber.

  6. Implementation and Test of the Automatic Flight Dynamics Operations for Geostationary Satellite Mission

    NASA Astrophysics Data System (ADS)

    Park, Sangwook; Lee, Young-Ran; Hwang, Yoola; Javier Santiago Noguero Galilea

    2009-12-01

    This paper describes the Flight Dynamics Automation (FDA) system for COMS Flight Dynamics System (FDS) and its test result in terms of the performance of the automation jobs. FDA controls the flight dynamics functions such as orbit determination, orbit prediction, event prediction, and fuel accounting. The designed FDA is independent from the specific characteristics which are defined by spacecraft manufacturer or specific satellite missions. Therefore, FDA could easily links its autonomous job control functions to any satellite mission control system with some interface modification. By adding autonomous system along with flight dynamics system, it decreases the operator’s tedious and repeated jobs but increase the usability and reliability of the system. Therefore, FDA is used to improve the completeness of whole mission control system’s quality. The FDA is applied to the real flight dynamics system of a geostationary satellite, COMS and the experimental test is performed. The experimental result shows the stability and reliability of the mission control operations through the automatic job control.

  7. SD-4060OCPLT4 program, user's guide

    NASA Technical Reports Server (NTRS)

    Glazer, J.

    1973-01-01

    A brief description of the Orbit Comparison Plot (OCPLT4) program is presented, along with user information and a source program listing. In addition to correcting several errors that existed in the original program, this program incorporates the following new features: (1) For any satellite whose observations are processed by the Definitive Orbit Determination System (DODS), the orbital uncertainty estimates (OUE) can be obtained via appropriate card input with no major modification to the program. (2) All satellite-related information (e.g., plotter scales, cutoff limits, plotting frequencies) is user controlled via card input. (3) Not all components of OUE must be obtained. The user has the option of obtaining only the radial component if there is no need for the other two components. (4) The altitude and time graph formats are controlled by the user and are not stored for specific satellites.

  8. Space shuttle orbiter trimmed center-of-gravity extension study. Volume 5: Effects of configuration modifications on the aerodynamic characteristics of the 140A/B orbiter at Mach numbers of 2.5, 3.95 and 4.6

    NASA Technical Reports Server (NTRS)

    Phillips, W. P.; Fournier, R. H.

    1979-01-01

    Supersonic aerodynamic characteristics are presented for the 140A/B space shuttle orbiter configuration (0.010 scale) and for the configuration modified to incorporate geometry changes in the wing planform fillet region. The modifications designed to extend the orbiter's longitudinal trim capability to more forward center-of-gravity locations, included reshaping of the baseline wing planform fillet and adding canards. The investigation was made in the high Mach number test section of the Langley Unitary Plan Wind Tunnel at a Reynolds number of approximately 2.2 million based on fuselage reference length. The angle-of-attack range for the investigation extended from -1 deg to 31 deg. Data were obtained with the elevators and body flap deflected at appropriate negative and positive conditions to assess the trim limits.

  9. New approaches for tracking earth orbiters using modified GPS ground receivers

    NASA Technical Reports Server (NTRS)

    Lichten, S. M.; Young, L. E.; Nandi, S.; Haines, B. J.; Dunn, C. E.; Edwards, C. D.

    1993-01-01

    A Global Positioning System (GPS) flight receiver provides a means to precisely determine orbits for satellites in low to moderate altitude orbits. Above a 5000-km altitude, however, relatively few GPS satellites are visible. New approaches to orbit determination for satellites at higher altitudes could reduce DSN antenna time needed to provide navigation and orbit determination support to future missions. Modification of GPS ground receivers enables a beacon from the orbiter to be tracked simultaneously with GPS data. The orbit accuracy expected from this GPS-like tracking (GLT) technique is expected to be in the range of a few meters or better for altitudes up to 100,000 km with a global ground network. For geosynchronous satellites, however, there are unique challenges due to geometrical limitations and to the lack of strong dynamical signature in tracking data. We examine two approaches for tracking the Tracking and Data Relay Satellite System (TDRSS) geostationary orbiters. One uses GLT with a global network; the other relies on a small 'connected element' ground network with a distributed clock for short-baseline differential carrier phase (SB Delta Phi). We describe an experiment planned for late 1993, which will combine aspects of both GLT and SB Delta Phi, to demonstrate a new approach for tracking the Tracking and Data Relay Satellites (TDRSs) that offers a number of operationally convenient and attractive features. The TDRS demonstration will be in effect a proof-of-concept experiment for a new approach to tracking spacecraft which could be applied more generally to deep-space as well as near-Earth regimes.

  10. MSFC Skylab structures and mechanical systems mission evaluation

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A performance analysis for structural and mechanical major hardware systems and components is presented. Development background testing, modifications, and requirement adjustments are included. Functional narratives are provided for comparison purposes as are predicted design performance criterion. Each item is evaluated on an individual basis: that is, (1) history (requirements, design, manufacture, and test); (2) in-orbit performance (description and analysis); and (3) conclusions and recommendations regarding future space hardware application. Overall, the structural and mechanical performance of the Skylab hardware was outstanding.

  11. Crew Transportation System Design Reference Missions

    NASA Technical Reports Server (NTRS)

    Mango, Edward J.

    2015-01-01

    Contains summaries of potential design reference mission goals for systems to transport humans to andfrom low Earth orbit (LEO) for the Commercial Crew Program. The purpose of this document is to describe Design Reference Missions (DRMs) representative of the end-to-end Crew Transportation System (CTS) framework envisioned to successfully execute commercial crew transportation to orbital destinations. The initial CTS architecture will likely be optimized to support NASA crew and NASA-sponsored crew rotation missions to the ISS, but consideration may be given in this design phase to allow for modifications in order to accomplish other commercial missions in the future. With the exception of NASA’s mission to the ISS, the remaining commercial DRMs are notional. Any decision to design or scar the CTS for these additional non-NASA missions is completely up to the Commercial Provider. As NASA’s mission needs evolve over time, this document will be periodically updated to reflect those needs.

  12. Design of multi-mission chemical propulsion modules for planetary orbiters. Volume 1: Summary report

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Results are presented of a conceptual design and feasibility study of chemical propulsion stages that can serve as modular propulsion units, with little or no modification, on a variety of planetary orbit missions, including orbiters of Mercury, Saturn, and Uranus. Planetary spacecraft of existing design or currently under development, viz., spacecraft of the Pioneer and Mariner families, are assumed as payload vehicles. Thus, operating requirements of spin-stabilized and 3-axis stabilized spacecraft have to be met by the respective propulsion module designs. As launch vehicle for these missions the Shuttle orbiter and interplanetary injection stage, or Tug, plus solid-propellant kick motor was assumed. Accommodation constraints and interfaces involving the payloads and the launch vehicle are considered in the propulsion module design. The applicability and performance advantages were evaluated of the space-storable high-energy bipropellants. The incentive for using this advanced propulsion technology on planetary missions is the much greater performance potential when orbit insertion velocities in excess of 4 km/sec are required, as in the Mercury orbiter. Design analyses and performance tradeoffs regarding earth-storable versus space-storable propulsion systems are included. Cost and development schedules of multi-mission versus custom-designed propulsion modules are examined.

  13. CAPS Simulation Environment Development

    NASA Technical Reports Server (NTRS)

    Murphy, Douglas G.; Hoffman, James A.

    2005-01-01

    The final design for an effective Comet/Asteroid Protection System (CAPS) will likely come after a number of competing designs have been simulated and evaluated. Because of the large number of design parameters involved in a system capable of detecting an object, accurately determining its orbit, and diverting the impact threat, a comprehensive simulation environment will be an extremely valuable tool for the CAPS designers. A successful simulation/design tool will aid the user in identifying the critical parameters in the system and eventually allow for automatic optimization of the design once the relationships of the key parameters are understood. A CAPS configuration will consist of space-based detectors whose purpose is to scan the celestial sphere in search of objects likely to make a close approach to Earth and to determine with the greatest possible accuracy the orbits of those objects. Other components of a CAPS configuration may include systems for modifying the orbits of approaching objects, either for the purpose of preventing a collision or for positioning the object into an orbit where it can be studied or used as a mineral resource. The Synergistic Engineering Environment (SEE) is a space-systems design, evaluation, and visualization software tool being leveraged to simulate these aspects of the CAPS study. The long-term goal of the SEE is to provide capabilities to allow the user to build and compare various CAPS designs by running end-to-end simulations that encompass the scanning phase, the orbit determination phase, and the orbit modification phase of a given scenario. Herein, a brief description of the expected simulation phases is provided, the current status and available features of the SEE software system is reported, and examples are shown of how the system is used to build and evaluate a CAPS detection design. Conclusions and the roadmap for future development of the SEE are also presented.

  14. Infrared Imagery of Shuttle (IRIS). Task 1

    NASA Technical Reports Server (NTRS)

    Chocol, C. J.

    1977-01-01

    Assessment of available IR sensor technology showed that the four aerothermodynamic conditions of interest during the entry trajectory of space shuttle can be accommodated by an aircraft flying parallel to the orbiter reentry ground track. Thermal information from the sides of the vehicle can be obtained with degraded performance (temperatures below 800 K) by flying the C-141 aircraft on the opposite side of the shuttle ground track and in the direction opposite that which is optimum for lower surface viewing. An acquisition system using a 6.25-cm aperture telescope and a single indium antimonide detector were designed to meet the acquisition requirements and interface with the 91.5-cm telescope with minimum modification. An image plane system using 600 indium antimonide detectors in two arrays which requires no modification to the existing telescope was also designed. Currently available components were used in a data handling system with interfaces with the experimentors station and the HP2100 computer.

  15. UNISAT-3 Power System

    NASA Astrophysics Data System (ADS)

    Santoni, Fabio; Piergentili, Fabrizio; Bulgarelli, Fabio; Graziani, Filippo

    2005-05-01

    An overview of the UNISAT-3 microsatellite power subsystem is given. This is an educational, low weight and low cost microsatellite designed, built, launched and operated in space by students and professors of Scuola di Ingegneria Aerospaziale, at University of Rome "La Sapienza". The satellite power system is based on terrestrial technology solar arrays and NiCd batteries. The microsatellite hosts other solar arrays, including multi-junction solar cells and mono- crystalline silicon high efficiency solar cells, in order to compare their behaviour in orbit. Moreover a MPPT (Maximum Power Point Tracking ) system has been designed and tested, and it is a technological payload of UNISAT-3. The MPPT design follows the studies performed in the field of solar powered racing cars, with modifications to make the system suitable for use in space. The system design, numerical simulation and hardware ground testing are described in the paper. The experiment and the performance evaluation criterion are described, together with the preliminary results of the first eight months of operation in orbit.

  16. ATTDES: An Expert System for Satellite Attitude Determination and Control. 2

    NASA Technical Reports Server (NTRS)

    Mackison, Donald L.; Gifford, Kevin

    1996-01-01

    The design, analysis, and flight operations of satellite attitude determintion and attitude control systems require extensive mathematical formulations, optimization studies, and computer simulation. This is best done by an analyst with extensive education and experience. The development of programs such as ATTDES permit the use of advanced techniques by those with less experience. Typical tasks include the mission analysis to select stabilization and damping schemes, attitude determination sensors and algorithms, and control system designs to meet program requirements. ATTDES is a system that includes all of these activities, including high fidelity orbit environment models that can be used for preliminary analysis, parameter selection, stabilization schemes, the development of estimators covariance analyses, and optimization, and can support ongoing orbit activities. The modification of existing simulations to model new configurations for these purposes can be an expensive, time consuming activity that becomes a pacing item in the development and operation of such new systems. The use of an integrated tool such as ATTDES significantly reduces the effort and time required for these tasks.

  17. Approximation method for a spherical bound system in the quantum plasma

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mehramiz, A.; Sobhanian, S.; Mahmoodi, J.

    2010-08-15

    A system of quantum hydrodynamic equations has been used for investigating the dielectric tensor and dispersion equation of a semiconductor as a quantum magnetized plasma. Dispersion relations and their modifications due to quantum effects are derived for both longitudinal and transverse waves. The number of states and energy levels are analytically estimated for a spherical bound system embedded in a semiconductor quantum plasma. The results show that longitudinal waves decay rapidly and do not interact with the spherical bound system. The energy shifts caused by the spin-orbit interaction and the Zeeman effect are calculated.

  18. KSC-04pd0545

    NASA Image and Video Library

    2004-03-17

    KENNEDY SPACE CENTER, FLA. - In the middeck of Endeavour, in the Orbiter Processing Facility, Center Director Jim Kennedy (far left) watches as a technician gets ready to lower himself through the LiOH door into the Environmental Control and Life Support System (ECLSS) bay. LiOH refers to lithium hydroxide, canisters of which are stored in the ECLSS bay under the middeck floor. During flight, cabin air from the cabin fan is ducted to two LiOH canisters, where carbon dioxide is removed and activated charcoal removes odors and trace contaminants. Kennedy is taking an opportunity to learn first-hand what workers are doing to enable Return to Flight. Endeavour is in an Orbiter Major Modification period.

  19. Orbit Transfer Vehicle Engine Study. Phase A, extension 1: Alternate low-thrust capability task report

    NASA Technical Reports Server (NTRS)

    Mellish, J. A.

    1980-01-01

    The feasibility and design impact of a requirement for the advanced expander cycle engine to be adaptable to extended low thrust operation of approximately 1K to 2K lb is assessed. It is determined that the orbit transfer vehicle point design engine can be reduced in thrust with minor injector modifications from 15K to 1K without significantly affecting combustion performance efficiency or injector face/chamber wall thermal compatibility. Likewise, high frequency transverse mode combustion instability is not expected to be detrimentally affected. Primarily, the operational limitations consist of feed system chugging instabilities and potential coupling of the injector response with the chamber longitudinal mode resonances under certain operating conditions. The recommended injector modification for low thrust operation is a change in the oxidizer injector element orifice size. Analyses also indicate that chamber coolant flow stability may be a concern below 2K 1bF operation and oxidizer pump stability could be a problem below a 2K thrust level although a recirculation flow could alleviate the problem.

  20. GSOSTATS Database: USAF Synchronous Satellite Catalog Data Conversion Software. User's Guide and Software Maintenance Manual, Version 2.1

    NASA Technical Reports Server (NTRS)

    Mallasch, Paul G.; Babic, Slavoljub

    1994-01-01

    The United States Air Force (USAF) provides NASA Lewis Research Center with monthly reports containing the Synchronous Satellite Catalog and the associated Two Line Mean Element Sets. The USAF Synchronous Satellite Catalog supplies satellite orbital parameters collected by an automated monitoring system and provided to Lewis Research Center as text files on magnetic tape. Software was developed to facilitate automated formatting, data normalization, cross-referencing, and error correction of Synchronous Satellite Catalog files before loading into the NASA Geosynchronous Satellite Orbital Statistics Database System (GSOSTATS). This document contains the User's Guide and Software Maintenance Manual with information necessary for installation, initialization, start-up, operation, error recovery, and termination of the software application. It also contains implementation details, modification aids, and software source code adaptations for use in future revisions.

  1. Crystal Growth Furnace System Configuration and Planned Experiments on the Second United States Microgravity Laboratory Mission

    NASA Technical Reports Server (NTRS)

    Srinivas, R.; Hambright, G.; Ainsworth, M.; Fiske, M.; Schaefer, D.

    1995-01-01

    The Crystal Growth Furnace (CGF) is currently undergoing modifications and refurbishment and is currently undergoing modifications and refurbishment and is manifested to refly on the Second United States Microgravity Laboratory (USML-2) mission scheduled for launch in September 1995. The CGF was developed for the National Aeronautics and Space Administration (NASA) under the Microgravity Science and Applications Division (MSAD) programs at NASA Headquarters. The refurbishment and reflight program is being managed by the Marshall Space Flight Center (MSFC) in Huntsville, Alabama. Funding and program support for the CGF project is provided to MSFC by the office of Life and Microgravity Sciences and Applications at NASA Headquarters. This paper presents an overview of the CGF system configuration for the USML-2 mission, and provides a brief description of the planned on-orbit experiment operation.

  2. Charged particle modification of ices in the Saturnian and Jovian systems

    NASA Technical Reports Server (NTRS)

    Johnson, R. E.; Barton, L. A.; Boring, J. W.; Jesser, W. A.; Brown, W. L.

    1985-01-01

    The modification by ion bombardment of the surfaces of icy objects in the Saturnian and Jovian systems is discussed. Chemical changes in ices are induced by breaking of bonds and by implantation of incident ions. Long-term irradiation by fast ions produces physical changes such as increasing the surface reflectivity and ability to scatter light. On large satellites, molecules which are ejected by ion bombardment are redistributed across the surfaces of large satellites. For small satellites and ring particles bombarded by ions, such as those of Saturn, most or all of the sputtered material is lost to space, forming a neutral torus in the locale of the satellite orbits and rings and supplying ions to the magnetosphere. Noting the existence of such a torus, the sputter erosion and possible stabilization of the E-ring of Saturn is discussed.

  3. An adaptable product for material processing and life science missions

    NASA Technical Reports Server (NTRS)

    Wassick, Gregory; Dobbs, Michael

    1995-01-01

    The Experiment Control System II (ECS-II) is designed to make available to the microgravity research community the same tools and mode of automated experimentation that their ground-based counterparts have enjoyed for the last two decades. The design goal was accomplished by combining commercial automation tools familiar to the experimenter community with system control components that interface with the on-orbit platform in a distributed architecture. The architecture insulates the tools necessary for managing a payload. By using commercial software and hardware components whenever possible, development costs were greatly reduced when compared to traditional space development projects. Using commercial-off-the-shelf (COTS) components also improved the usability documentation, and reducing the need for training of the system by providing familiar user interfaces, providing a wealth of readily available documentation, and reducing the need for training on system-specific details. The modularity of the distributed architecture makes it very amenable for modification to different on-orbit experiments requiring robotics-based automation.

  4. Aerodynamics of Reentry Vehicle Clipper at Descent Phase

    NASA Astrophysics Data System (ADS)

    Semenov, Yu. P.; Reshetin, A. G.; Dyadkin, A. A.; Petrov, N. K.; Simakova, T. V.; Tokarev, V. A.

    2005-02-01

    From Gagarin spacecraft to reusable orbiter Buran, RSC Energia has traveled a long way in the search for the most optimal and, which is no less important, the most reliable spacecraft for manned space flight. During the forty years of space exploration, in cooperation with a broad base of subcontractors, a number of problems have been solved which assure a safe long stay in space. Vostok and Voskhod spacecraft were replaced with Soyuz supporting a crew of three. During missions to a space station, it provides crew rescue capability in case of a space station emergency at all times (the spacecraft life is 200 days).The latest modification of Soyuz spacecraft -Soyuz TMA -in contrast to its predecessors, allows to become a space flight participant to a person of virtually any anthropometric parameters with a mass of 50 to 95 kg capable of withstanding up to 6 g load during descent. At present, Soyuz TMA spacecraft are the state-of-the-art, reliable and only means of the ISS crew delivery, in-flight support and return. Introduced on the basis of many years of experience in operation of manned spacecraft were not only the principles of deep redundancy of on-board systems and equipment, but, to assure the main task of the spacecraft -the crew return to Earth -the principles of functional redundancy. That is, vital operations can be performed by different systems based on different physical principles. The emergency escape system that was developed is the only one in the world that provides crew rescue in case of LV failure at any phase in its flight. Several generations of space stations that have been developed have broadened, virtually beyond all limits, capabilities of man in space. The docking system developed at RSC Energia allowed not only to dock spacecraft in space, but also to construct in orbit various complex space systems. These include large space stations, and may include in the future the in-orbit construction of systems for the exploration of the Moon and Mars.. Logistics spacecraft Progress have been flying regularly since 1978. The tasks of these unmanned spacecraft include supplying the space station with all the necessities for long-duration missions, such as propellant for the space station propulsion system, crew life support consumables, scientific equipment for conducting experiments. Various modifications of the spacecraft have expanded the space station capabilities. 1988 saw the first, and, much to our regret, the last flight of the reusable orbiter Buran.. Buran could deliver to orbit up to 30 tons of cargo, return 20 tons to Earth and have a crew of up to 10. However, due to our country's economic situation the project was suspended.

  5. Space Shuttle Orbiter trimmed center-of-gravity extension study. Volume 7: Effects of configuration modifications on the subsonic aerodynamic characteristics of the 1140 A/B orbbiter at high Reynolds numbers. [Langley low turbulence pressure tunnel

    NASA Technical Reports Server (NTRS)

    Phillips, W. P.

    1981-01-01

    Subsonic longitudinal andd laternal directional characteristics were obtained for several modified configurations of the 140 A/B orbiter (0.010 scale). These modifications, designed to extend longitudinal trim capability forward of the 65 percent fuselage length station, consisted of modified wing planform fillet and a canard. Tests were performed in the Langley Low Turbulence Pressure Tunnel at Reynolds numbers from about 4.2 million to 14.3 million based on the fuselage reference length.

  6. Study of application of adaptive systems to the exploration of the solar system. Volume 3: Mars landed systems

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The results of a more detailed study of three missions to the surface of Mars: (1) an advanced lander, (2) a lander with a small tethered rover, and (3) a lander with a medium sized rover that operates independently of the lander for most of its functions but communicates with Earth through the lander are presented. For all three missions it was assumed that the Viking orbiter and lander would be used with modifications as required to improve the science package, to accommodate the rovers, and to handle the increased payloads.

  7. The formation of giant planets in wide orbits by photoevaporation-synchronized migration

    NASA Astrophysics Data System (ADS)

    Guilera, O. M.; Miller Bertolami, M. M.; Ronco, M. P.

    2017-10-01

    The discovery of giant planets in wide orbits represents a major challenge for planet formation theory. In the standard core accretion paradigm, planets are expected to form at radial distances ≲20 au in order to form massive cores (with masses ≳10 M⊕) able to trigger the gaseous runaway growth before the dissipation of the disc. This has encouraged authors to find modifications of the standard scenario as well as alternative theories like the formation of planets by gravitational instabilities in the disc to explain the existence of giant planets in wide orbits. However, there is not yet consensus on how these systems are formed. In this Letter, we present a new natural mechanism for the formation of giant planets in wide orbits within the core accretion paradigm. If photoevaporation is considered, after a few Myr of viscous evolution a gap in the gaseous disc is opened. We found that, under particular circumstances planet migration becomes synchronized with the evolution of the gap, which results in an efficient outward planet migration. This mechanism is found to allow the formation of giant planets with masses Mp ≲ 1MJup in wide stable orbits as large as ∼130 au from the central star.

  8. Infrared On-Orbit RCC Inspection With the EVA IR Camera: Development of Flight Hardware From a COTS System

    NASA Technical Reports Server (NTRS)

    Gazanik, Michael; Johnson, Dave; Kist, Ed; Novak, Frank; Antill, Charles; Haakenson, David; Howell, Patricia; Jenkins, Rusty; Yates, Rusty; Stephan, Ryan; hide

    2005-01-01

    In November 2004, NASA's Space Shuttle Program approved the development of the Extravehicular (EVA) Infrared (IR) Camera to test the application of infrared thermography to on-orbit reinforced carbon-carbon (RCC) damage detection. A multi-center team composed of members from NASA's Johnson Space Center (JSC), Langley Research Center (LaRC), and Goddard Space Flight Center (GSFC) was formed to develop the camera system and plan a flight test. The initial development schedule called for the delivery of the system in time to support STS-115 in late 2005. At the request of Shuttle Program managers and the flight crews, the team accelerated its schedule and delivered a certified EVA IR Camera system in time to support STS-114 in July 2005 as a contingency. The development of the camera system, led by LaRC, was based on the Commercial-Off-the-Shelf (COTS) FLIR S65 handheld infrared camera. An assessment of the S65 system in regards to space-flight operation was critical to the project. This paper discusses the space-flight assessment and describes the significant modifications required for EVA use by the astronaut crew. The on-orbit inspection technique will be demonstrated during the third EVA of STS-121 in September 2005 by imaging damaged RCC samples mounted in a box in the Shuttle's cargo bay.

  9. Transport through graphenelike flakes with intrinsic spin-orbit interactions

    NASA Astrophysics Data System (ADS)

    Weymann, I.; Barnaś, J.; Krompiewski, S.

    2015-07-01

    It was shown recently [J. L. Lado and J. Fernández-Rossier, Phys. Rev. Lett. 113, 027203 (2014), 10.1103/PhysRevLett.113.027203] that edge magnetic moments in graphene-like nanoribbons are strongly influenced by the intrinsic spin-orbit interaction. Due to this interaction an anisotropy comes about which makes the in-plane arrangement of magnetic moments energetically more favorable than that corresponding to the out-of-plane configuration. In this paper we raise both the edge magnetism problem and the differential conductance and shot noise Fano factor issues, in the context of finite-size flakes within the Coulomb blockade (CB) transport regime. Our findings elucidate the following problems: (i) modification of CB diamonds by the appearance of in-plane magnetic moments and (ii) modification of CB diamonds by the intrinsic spin-orbit interaction.

  10. KSC-07pd1774

    NASA Image and Video Library

    2007-07-03

    KENNEDY SPACE CENTER, FLA. -- The main engines on the orbiter Endeavour (upper right) are seen as Endeavour is lowered into high bay 1 of the Vehicle Assembly Building for stacking with the external tank (seen at left) and solid rocket boosters on the mobile launcher platform. Endeavour will be launched on mission STS-118, its first flight in more than four years. The shuttle has undergone extensive modifications, including the addition of safety upgrades already added to shuttles Discovery and Atlantis. Endeavour also features new hardware, such as the Station-to-Shuttle Power Transfer System that will allow the docked shuttle to draw electrical power from the station and extend its visits to the orbiting lab. Endeavour is targeted for launch on Aug. 7. Photo credit: NASA/Troy Cryder

  11. Orbiter/payload proximity operations SES Postsim report. Lateral approach and other techniques

    NASA Technical Reports Server (NTRS)

    Olszewski, O.

    1978-01-01

    Various approach and stationkeeping simulations (proximity operations) were conducted in the Shuttle engineering simulator (SES). This simulator is the first to dynamically include the Orbiter reaction control system (RCS) plume effects on a payload being recovered after rendezvous operations. A procedure for braking, using the simultaneous firing of both jets, was evaluated and found very useful for proximity operations. However this procedure is very inefficient in the RCS usage and requires modifications to the digital autopilot (DAP) software. A new final approach, the lateral approach technique (LAT), or the momentum vector proximity approach, was also evaluated in the simulations. The LAT, which included a tailfirst approach for braking, was evaluated successfully with both inertial and gravity stabilized payloads.

  12. A rapid method of estimating the collision frequencies between the earth and the earth-crossing bodies

    NASA Technical Reports Server (NTRS)

    Su, Shin-Yi; Kessler, Donald J.

    1991-01-01

    The present study examines a very fast method of calculating the collision frequency between two low-eccentricity orbiting bodies for evaluating the evolution of earth-orbiting objects such as space debris. The results are very accurate and the required computer time is negligible. The method is now applied without modification to calculate the collision frequencies for moderately and highly eccentric orbits.

  13. External electric field driven modification of the anomalous and spin Hall conductivities in Fe thin films on MgO(001)

    NASA Astrophysics Data System (ADS)

    Pradipto, Abdul-Muizz; Akiyama, Toru; Ito, Tomonori; Nakamura, Kohji

    2018-01-01

    The effects of applying external electric fields to the anomalous and spin Hall conductivities in Fe thin-film models with different layer thicknesses on MgO(001) are investigated by using first-principles calculations. We observe that, for the considered systems, the application of positive electric field associated with the accumulation of negative charges on the Fe side generally decreases (increases) the anomalous (spin) Hall conductivities. The mapping of the Hall conductivities within the two-dimensional Brillouin zone shows that the electric-field-induced modifications are related to the modification of the band structures of the atoms at the interface with the MgO substrate. In particular, the external electric field affects the Hall conductivities via the modifications of the dx z,dy z orbitals, in which the application of positive electric field pushes the minority-spin states of the dx z,dy z bands closer to the Fermi level. Better agreement with the anomalous Hall conductivity for bulk Fe and a more realistic scenario for the electric field modification of Hall conductivities are obtained by using the thicker layers of Fe on MgO (Fe3/MgO and Fe5/MgO).

  14. KSC-04PD-0554

    NASA Technical Reports Server (NTRS)

    2004-01-01

    KENNEDY SPACE CENTER, FLA. Under a workers watchful eyes in the Orbiter Processing Facility, Center Director Jim Kennedy (right) takes a turn on a screw on Endeavour. Kennedy is taking an opportunity to learn first-hand what workers are doing to enable Return to Flight. Endeavour is in an Orbiter Major Modification period.

  15. KSC-04PD-0551

    NASA Technical Reports Server (NTRS)

    2004-01-01

    KENNEDY SPACE CENTER, FLA. Under a workers watchful eyes in the Orbiter Processing Facility, Center Director Jim Kennedy (right) takes a turn on a screw on Endeavour. Kennedy is taking an opportunity to learn first-hand what workers are doing to enable Return to Flight. Endeavour is in an Orbiter Major Modification period.

  16. Hypervelocity Impact Test Fragment Modeling: Modifications to the Fragment Rotation Analysis and Lightcurve Code

    NASA Technical Reports Server (NTRS)

    Gouge, Michael F.

    2011-01-01

    Hypervelocity impact tests on test satellites are performed by members of the orbital debris scientific community in order to understand and typify the on-orbit collision breakup process. By analysis of these test satellite fragments, the fragment size and mass distributions are derived and incorporated into various orbital debris models. These same fragments are currently being put to new use using emerging technologies. Digital models of these fragments are created using a laser scanner. A group of computer programs referred to as the Fragment Rotation Analysis and Lightcurve code uses these digital representations in a multitude of ways that describe, measure, and model on-orbit fragments and fragment behavior. The Dynamic Rotation subroutine generates all of the possible reflected intensities from a scanned fragment as if it were observed to rotate dynamically while in orbit about the Earth. This calls an additional subroutine that graphically displays the intensities and the resulting frequency of those intensities as a range of solar phase angles in a Probability Density Function plot. This document reports the additions and modifications to the subset of the Fragment Rotation Analysis and Lightcurve concerned with the Dynamic Rotation and Probability Density Function plotting subroutines.

  17. Rendezvous and Proximity Operations of the Space Shuttle

    NASA Technical Reports Server (NTRS)

    Goodman, John L.

    2005-01-01

    Space Shuttle rendezvous missions present unique challenges that were not fully recognized when the Shuttle was designed. Rendezvous targets could be passive (i.e., no lights or transponders), and not designed to facilitate Shuttle rendezvous, proximity operations, and retrieval. Shuttle reaction control system jet plume impingement on target spacecraft presented induced dynamics, structural loading, and contamination concerns. These issues, along with limited reaction control system propellant in the Shuttle nose, drove a change from the legacy Gemini/Apollo coelliptic profile to a stable orbit profile, and the development of new proximity operations techniques. Multiple scientific and on-orbit servicing missions, and crew exchange, assembly and replenishment flights to Mir and to the International Space Station drove further profile and piloting technique changes. These changes included new proximity operations, relative navigation sensors, and new computer generated piloting cues. However, the Shuttle's baseline rendezvous navigation system has not required modification to place the Shuttle at the proximity operations initiation point for all rendezvous missions flown.

  18. Space-Based Solar Power Conversion and Delivery Systems Study. Volume 3: Microwave Power Transmission Studies

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The Microwave Fower Beam Ionosphere effects and critical interfaces between th Microwave Power Transmission System (MPTS) and the Satellite were studied as part of the NASA/MSFC continuing research on the feasibility of power transmission from geosynchronous orbit. Theoretical predications of ionospheric modifications produced by the direct interaction of the MPTS on the earth's upper atmosphere are used to determine their impact on the performance of the Microwave Power Beam and Pilot Beam System as well as on other RF systems effected by the ionosphere. A technology program to quantitatively define these interactions is developed. Critical interface areas between the MPTS and the satellite which could have a major impact on cost and performance of the power system are idenfified and analyzed. The areas selected include: use of either a 20 kV versus 40 kV Amplitron, thermal blockage effects of Amplitron heat radiation by the satellite structure, effect of dielectric carry-through structure on power beam, and effect of material sublimation on performance of the Amplitron in Geosynchronous Orbit.

  19. Cabana Multi-User Spaceport Tour of KSC

    NASA Image and Video Library

    2017-02-17

    Kennedy Space Center Director Bob Cabana speaks to members of the news media on the balcony of Operations Support Building II describing the site's transition from a primarily government-only facility to a premier, multi-user spaceport. In the background is the Vehicle Assembly Building (VAB). Modifications were recently completed in the VAB where new work platforms were installed to support processing of NASA's Space Launch System rocket designed to send the Orion spacecraft on missions beyond low-Earth orbit.

  20. Transonic stability and control characteristics of a 0.015 scale model 69-0 of the space shuttle orbiter with forebody RSI modification in the NASA/LaRC 8 foot TPT (LA72)

    NASA Technical Reports Server (NTRS)

    Ball, J. W.; Edwards, C. R.

    1976-01-01

    Tests were conducted in the NASA/LaRC 8 foot transonic wind tunnel from March 26 through 31, 1976. The model was a 0.015 scale SSV Orbiter with forebody modifications to simulate slight reductions in the reusable surface insulation (RSI) thickness. Six component aerodynamic force and moment data were obtained at Mach numbers from 0.35 to 1.20 over an angle of attack range from -2 deg to 20 deg at sideslip angles of 0 deg and 5 deg.

  1. Implementation of Altimetry Data in the GIPSY POD Software Package

    NASA Technical Reports Server (NTRS)

    Stauch, Jason R.; Gold, Kenn; Born, George H.

    2001-01-01

    Altimetry data has been used extensively to acquire data about characteristics of the Earth, the Moon, and Mars. More recently, the idea of using altimetry for orbit determination has also been explored. This report discusses modifications to JPL's GIPSY/OASIS II software to include altimetry data as an observation type for precise orbit determination. The mathematical foundation of using altimetry for the purpose of orbit determination is presented, along with results.

  2. Gas release and conductivity modification studies

    NASA Technical Reports Server (NTRS)

    Linson, L. M.; Baxter, D. C.

    1979-01-01

    The behavior of gas clouds produced by releases from orbital velocity in either a point release or venting mode is described by the modification of snowplow equations valid in an intermediate altitude regime. Quantitative estimates are produced for the time dependence of the radius of the cloud, the average internal energy, the translational velocity, and the distance traveled. The dependence of these quantities on the assumed density profile, the internal energy of the gas, and the ratio of specific heats is examined. The new feature is the inclusion of the effect of the large orbital velocity. The resulting gas cloud models are used to calculate the characteristics of the field line integrated Pedersen conductivity enhancements that would be produced by the release of barium thermite at orbital velocity in either the point release or venting modes as a function of release altitude and chemical payload weight.

  3. Rocket nozzle expansion ratio analysis for dual-fuel earth-to-orbit vehicles

    NASA Technical Reports Server (NTRS)

    Martin, James A.

    1989-01-01

    Results are reported from a recent study of the effects of Space Shuttle Main Engine expansion ratio modifications, in the cases of both single-stage and two-stage systems. Two-position nozzles were employed; after varying the lower expansion ratio while the higher was held constant at 120, the lower expansion ratio was held constant at 40 or 60 while the higher expansion ratio was varied. The expansion ratios for minimum vehicle dry mass are different for single-stage and two-stage systems. For two-stage systems, a single expansion ratio of 77.5 provides a lower dry mass than any two-position nozzle.

  4. COOP 3D ARPA Experiment 109 National Center for Atmospheric Research

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Coupled atmospheric and hydrodynamic forecast models were executed on the supercomputing resources of the National Center for Atmospheric Research (NCAR) in Boulder, Colorado and the Ohio Supercomputing Center (OSC)in Columbus, Ohio. respectively. The interoperation of the forecast models on these geographically diverse, high performance Cray platforms required the transfer of large three dimensional data sets at very high information rates. High capacity, terrestrial fiber optic transmission system technologies were integrated with those of an experimental high speed communications satellite in Geosynchronous Earth Orbit (GEO) to test the integration of the two systems. Operation over a spacecraft in GEO orbit required modification of the standard configuration of legacy data communications protocols to facilitate their ability to perform efficiently in the changing environment characteristic of a hybrid network. The success of this performance tuning enabled the use of such an architecture to facilitate high data rate, fiber optic quality data communications between high performance systems not accessible to standard terrestrial fiber transmission systems. Thus obviating the performance degradation often found in contemporary earth/satellite hybrids.

  5. Infrared Imagery of Shuttle (IRIS). Task 1, summary report

    NASA Technical Reports Server (NTRS)

    Chocol, C. J.

    1977-01-01

    The feasibility of remote, high-resolution infrared imagery of the Shuttle Orbiter lower surface during entry to obtain accurate measurements of aerodynamic heat transfer was demonstrated. Using available technology, such images can be taken from an existing aircraft/telescope system (the C141 AIRO) with minimum modification or addition of systems. Images with a spatial resolution of 1 m or better and a temperature resolution of 2.5% between temperatures of 800 and 1900 K can be obtained. Data reconstruction techniques can provide a geometrically and radiometrically corrected array on addressable magnetic tape ready for display by NASA.

  6. On space-based SETI

    NASA Technical Reports Server (NTRS)

    Stuiver, Willem

    1990-01-01

    Space-based antenna systems for the search of signals from extra-terrestrial intelligence are discussed. Independent studies of the ecliptic solar-sailing transfer problem from the geosynchronous departure orbit to Sun-Earth collinear transterrestrial liberation point were conducted. They were based on a relatively simple mathematical model describing attitude-controlled spacecraft motion in the ecliptic plane as governed by solar and terrestrial gravitational attraction together with the solar radiation pressure. The resulting equations of motion were integrated numerically for a relevant range of values of spacecraft area-to-mass ratio and for an appropriate spacecraft attitude-control law known to lead to Earth escape. Experimentation with varying initial conditions in the departure orbit, and with attitude-control law modification after having achieved Earth escape, established the feasibility of component deployment by means of solar sailing. Details are presented.

  7. Propulsion and fluid management - Station keeping will eat energy on a new scale

    NASA Technical Reports Server (NTRS)

    Petrash, D. A.

    1983-01-01

    An attempt is made to identify technologies that could be brought to a state of minimal development risk in the near term, yet offer the potential for evolutionary growth consistent with future space station propulsion requirements. Prospective auxiliary propulsion propellants will be usable by other systems, thereby offering resupply benefits and a benign rather than corrosive or toxic handling environment. NASA programs are currently underway to develop the storage and supply methods for cryogenic liquids in orbit. The recovery of unused propellants from the Space Shuttle Orbiter and External Tank are being evaluated in order to define Shuttle modifications and performance penalties. Fluid management subsystem requirements and characteristics cannot, however, be fully defined until a firm mission scenario has been established and other space station subsystems are more clearly defined.

  8. Powered Explicit Guidance Modifications and Enhancements for Space Launch System Block-1 and Block-1B Vehicles

    NASA Technical Reports Server (NTRS)

    Von der Porten, Paul; Ahmad, Naeem; Hawkins, Matt; Fill, Thomas

    2018-01-01

    NASA is currently building the Space Launch System (SLS) Block-1 launch vehicle for the Exploration Mission 1 (EM-1) test flight. NASA is also currently designing the next evolution of SLS, the Block-1B. The Block-1 and Block-1B vehicles will use the Powered Explicit Guidance (PEG) algorithm (of Space Shuttle heritage) for closed loop guidance. To accommodate vehicle capabilities and design for future evolutions of SLS, modifications were made to PEG for Block-1 to handle multi-phase burns, provide PEG updated propulsion information, and react to a core stage engine out. In addition, due to the relatively low thrust-to-weight ratio of the Exploration Upper Stage (EUS) and EUS carrying out Lunar Vicinity and Earth Escape missions, certain enhancements to the Block-1 PEG algorithm are needed to perform Block-1B missions to account for long burn arcs and target translunar and hyperbolic orbits. This paper describes the design and implementation of modifications to the Block-1 PEG algorithm as compared to Space Shuttle. Furthermore, this paper illustrates challenges posed by the Block-1B vehicle and the required PEG enhancements. These improvements make PEG capable for use on the SLS Block-1B vehicle as part of the Guidance, Navigation, and Control (GN&C) System.

  9. Selection process for trade study: Reusable Hydrogen Composite Tank System (RHCTS)

    NASA Astrophysics Data System (ADS)

    Greenberg, H. S.

    1994-09-01

    This document describes the selection process that will be used to identify the most suitable structural configuration option for an SSTO winged vehicle capable of delivering 25,000 lbs to a 220 nm circular orbit at 51.6 degree inclination. The most suitable RHCTS is within this configuration and will be the prototype design for subsequent design and analysis and the basis for the design and fabrication of a scale test article to be subjected to life cycle testing. The selection process for this TA 1 trade study is the same as that for the TA 2 trade study. As the trade study progresses additional insight may result in modifications to the selection criteria within in this process. Such modifications will result in an update of this document as appropriate.

  10. Comparative evaluation of existing expendable upper stages for space shuttle

    NASA Technical Reports Server (NTRS)

    Weyers, V. J.; Sagerman, G. D.; Borsody, J.; Lubick, R. J.

    1974-01-01

    The use of existing expendable upper stages in the space shuttle during its early years of operation is evaluated. The Burner 2, Scout, Delta, Agena, Transtage, and Centaur were each studied under contract by their respective manufacturers to determine the extent and cost of the minimum modifications necessary to integrate the stage with the shuttle orbiter. A comparative economic analysis of thirty-five different families of these stages is discussed. Results show that the overall transportation system cost differences between many of the families are quite small. However, by considering several factors in addition to cost, it is possible to select one family as being representative of the capability of the minimum modification existing stage approach. The selected family meets all of the specified mission requirements during the early years of shuttle operation.

  11. Cabana Multi-User Spaceport Tour of KSC

    NASA Image and Video Library

    2017-02-17

    Nancy Bray, director of Spaceport Integration and Services at NASA's Kennedy Space Center, speaks to members of the news media on the balcony of Operations Support Building II describing the site's transition from a primarily government-only facility to a premier, multi-user spaceport. In the background is the Vehicle Assembly Building (VAB). Modifications were recently completed in the VAB where new work platforms were installed to support processing of NASA's Space Launch System rocket designed to send the Orion spacecraft on missions beyond low-Earth orbit.

  12. Cabana Multi-User Spaceport Tour of KSC

    NASA Image and Video Library

    2017-02-17

    Tom Engler, director of Center Planning and Development at NASA's Kennedy Space Center, speaks to members of the news media on the balcony of Operations Support Building II describing the site's transition from a primarily government-only facility to a premier, multi-user spaceport. In the background is the Vehicle Assembly Building (VAB). Modifications were recently completed in the VAB where new work platforms were installed to support processing of NASA's Space Launch System rocket designed to send the Orion spacecraft on missions beyond low-Earth orbit.

  13. Decentralized formation flying control in a multiple-team hierarchy.

    PubMed

    Mueller, Joseph B; Thomas, Stephanie J

    2005-12-01

    In recent years, formation flying has been recognized as an enabling technology for a variety of mission concepts in both the scientific and defense arenas. Examples of developing missions at NASA include magnetospheric multiscale (MMS), solar imaging radio array (SIRA), and terrestrial planet finder (TPF). For each of these missions, a multiple satellite approach is required in order to accomplish the large-scale geometries imposed by the science objectives. In addition, the paradigm shift of using a multiple satellite cluster rather than a large, monolithic spacecraft has also been motivated by the expected benefits of increased robustness, greater flexibility, and reduced cost. However, the operational costs of monitoring and commanding a fleet of close-orbiting satellites is likely to be unreasonable unless the onboard software is sufficiently autonomous, robust, and scalable to large clusters. This paper presents the prototype of a system that addresses these objectives-a decentralized guidance and control system that is distributed across spacecraft using a multiple team framework. The objective is to divide large clusters into teams of "manageable" size, so that the communication and computation demands driven by N decentralized units are related to the number of satellites in a team rather than the entire cluster. The system is designed to provide a high level of autonomy, to support clusters with large numbers of satellites, to enable the number of spacecraft in the cluster to change post-launch, and to provide for on-orbit software modification. The distributed guidance and control system will be implemented in an object-oriented style using a messaging architecture for networking and threaded applications (MANTA). In this architecture, tasks may be remotely added, removed, or replaced post launch to increase mission flexibility and robustness. This built-in adaptability will allow software modifications to be made on-orbit in a robust manner. The prototype system, which is implemented in Matlab, emulates the object-oriented and message-passing features of the MANTA software. In this paper, the multiple team organization of the cluster is described, and the modular software architecture is presented. The relative dynamics in eccentric reference orbits is reviewed, and families of periodic, relative trajectories are identified, expressed as sets of static geometric parameters. The guidance law design is presented, and an example reconfiguration scenario is used to illustrate the distributed process of assigning geometric goals to the cluster. Next, a decentralized maneuver planning approach is presented that utilizes linear-programming methods to enact reconfiguration and coarse formation keeping maneuvers. Finally, a method for performing online collision avoidance is discussed, and an example is provided to gauge its performance.

  14. Houston Operations Predictor/Estimator (HOPE) programming manual, volume 1. [Apollo orbit determination

    NASA Technical Reports Server (NTRS)

    Daly, J. K.

    1974-01-01

    The programming techniques used to implement the equations and mathematical techniques of the Houston Operations Predictor/Estimator (HOPE) orbit determination program on the UNIVAC 1108 computer are described. Detailed descriptions are given of the program structure, the internal program structure, the internal program tables and program COMMON, modification and maintainence techniques, and individual subroutine documentation.

  15. KSC01padig095

    NASA Image and Video Library

    2001-02-24

    [Photo courtesy of Boeing photographer Bob Williams.] The orbiter Columbia, atop a modified Boeing 747, rolls under protective cover at Palmdale, Calif. Columbia has been undergoing modifications and upgrades at Boeing’s Orbiter Assembly Facility in Palmdale and is ready to return to Kennedy Space Center. Ferry preparations and the flight plan are contingent upon weather conditions in California and enroute to Florida.

  16. RS-34 Phoenix (Peacekeeper Post Boost Propulsion System) Utilization Study

    NASA Technical Reports Server (NTRS)

    Esther, Elizabeth A.; Kos, Larry; Bruno, Cy

    2012-01-01

    The Advanced Concepts Office (ACO) at the NASA Marshall Space Flight Center (MSFC) in conjunction with Pratt & Whitney Rocketdyne conducted a study to evaluate potential in-space applications for the Rocketdyne produced RS-34 propulsion system. The existing RS-34 propulsion system is a remaining asset from the decommissioned United States Air Force Peacekeeper ICBM program; specifically the pressure-fed storable bipropellant Stage IV Post Boost Propulsion System, renamed Phoenix. MSFC gained experience with the RS-34 propulsion system on the successful Ares I-X flight test program flown in October 2009. RS-34 propulsion system components were harvested from stages supplied by the USAF and used on the Ares I-X Roll control system (RoCS). The heritage hardware proved extremely robust and reliable and sparked interest for further utilization on other potential in-space applications. Subsequently, MSFC is working closely with the USAF to obtain all the remaining RS-34 stages for re-use opportunities. Prior to pursuit of securing the hardware, MSFC commissioned the Advanced Concepts Office to understand the capability and potential applications for the RS-34 Phoenix stage as it benefits NASA, DoD, and commercial industry. Originally designed, the RS-34 Phoenix provided in-space six-degrees-of freedom operational maneuvering to deploy multiple payloads at various orbital locations. The RS-34 Phoenix Utilization Study sought to understand how the unique capabilities of the RS-34 Phoenix and its application to six candidate missions: 1) small satellite delivery (SSD), 2) orbital debris removal (ODR), 3) ISS re-supply, 4) SLS kick stage, 5) manned GEO servicing precursor mission, and an Earth-Moon L-2 Waypoint mission. The small satellite delivery and orbital debris removal missions were found to closely mimic the heritage RS-34 mission. It is believed that this technology will enable a small, low-cost multiple satellite delivery to multiple orbital locations with a single boost. For both the small satellite delivery and the orbital debris mission candidates, the RS-34 Phoenix requires the least amount of modification to the existing hardware. The results of the RS-34 Phoenix Utilization Study show that the system is technically sufficient to successfully support all of the missions analyzed

  17. RS-34 Phoenix (Peacekeeper Post Boost Propulsion System) Utilization Study

    NASA Technical Reports Server (NTRS)

    Esther, Elizabeth A.; Kos, Larry; Burnside, Christopher G.; Bruno, Cy

    2013-01-01

    The Advanced Concepts Office (ACO) at the NASA Marshall Space Flight Center (MSFC) in conjunction with Pratt & Whitney Rocketdyne conducted a study to evaluate potential in-space applications for the Rocketdyne produced RS-34 propulsion system. The existing RS-34 propulsion system is a remaining asset from the de-commissioned United States Air Force Peacekeeper ICBM program, specifically the pressure-fed storable bipropellant Stage IV Post Boost Propulsion System, renamed Phoenix. MSFC gained experience with the RS-34 propulsion system on the successful Ares I-X flight test program flown in October 2009. RS-34 propulsion system components were harvested from stages supplied by the USAF and used on the Ares I-X Roll control system (RoCS). The heritage hardware proved extremely robust and reliable and sparked interest for further utilization on other potential in-space applications. MSFC is working closely with the USAF to obtain RS-34 stages for re-use opportunities. Prior to pursuit of securing the hardware, MSFC commissioned the Advanced Concepts Office to understand the capability and potential applications for the RS-34 Phoenix stage as it benefits NASA, DoD, and commercial industry. As originally designed, the RS-34 Phoenix provided in-space six-degrees-of freedom operational maneuvering to deploy multiple payloads at various orbital locations. The RS-34 Phoenix Utilization Study sought to understand how the unique capabilities of the RS-34 Phoenix and its application to six candidate missions: 1) small satellite delivery (SSD), 2) orbital debris removal (ODR), 3) ISS re-supply, 4) SLS kick stage, 5) manned GEO servicing precursor mission, and an Earth-Moon L-2 Waypoint mission. The small satellite delivery and orbital debris removal missions were found to closely mimic the heritage RS-34 mission. It is believed that this technology will enable a small, low-cost multiple satellite delivery to multiple orbital locations with a single boost. For both the small satellite delivery and the orbital debris mission candidates, the RS-34 Phoenix requires the least amount of modification to the existing hardware. The results of the RS-34 Phoenix Utilization Study show that the system is technically sufficient to successfully support all of the missions analyzed.

  18. Selection of Thermal Worst-Case Orbits via Modified Efficient Global Optimization

    NASA Technical Reports Server (NTRS)

    Moeller, Timothy M.; Wilhite, Alan W.; Liles, Kaitlin A.

    2014-01-01

    Efficient Global Optimization (EGO) was used to select orbits with worst-case hot and cold thermal environments for the Stratospheric Aerosol and Gas Experiment (SAGE) III. The SAGE III system thermal model changed substantially since the previous selection of worst-case orbits (which did not use the EGO method), so the selections were revised to ensure the worst cases are being captured. The EGO method consists of first conducting an initial set of parametric runs, generated with a space-filling Design of Experiments (DoE) method, then fitting a surrogate model to the data and searching for points of maximum Expected Improvement (EI) to conduct additional runs. The general EGO method was modified by using a multi-start optimizer to identify multiple new test points at each iteration. This modification facilitates parallel computing and decreases the burden of user interaction when the optimizer code is not integrated with the model. Thermal worst-case orbits for SAGE III were successfully identified and shown by direct comparison to be more severe than those identified in the previous selection. The EGO method is a useful tool for this application and can result in computational savings if the initial Design of Experiments (DoE) is selected appropriately.

  19. Vulnerability of manned spacecraft to crew loss from orbital debris penetration

    NASA Technical Reports Server (NTRS)

    Williamsen, J. E.

    1994-01-01

    Orbital debris growth threatens the survival of spacecraft systems from impact-induced failures. Whereas the probability of debris impact and spacecraft penetration may currently be calculated, another parameter of great interest to safety engineers is the probability that debris penetration will cause actual spacecraft or crew loss. Quantifying the likelihood of crew loss following a penetration allows spacecraft designers to identify those design features and crew operational protocols that offer the highest improvement in crew safety for available resources. Within this study, a manned spacecraft crew survivability (MSCSurv) computer model is developed that quantifies the conditional probability of losing one or more crew members, P(sub loss/pen), following the remote likelihood of an orbital debris penetration into an eight module space station. Contributions to P(sub loss/pen) are quantified from three significant penetration-induced hazards: pressure wall rupture (explosive decompression), fragment-induced injury, and 'slow' depressurization. Sensitivity analyses are performed using alternate assumptions for hazard-generating functions, crew vulnerability thresholds, and selected spacecraft design and crew operations parameters. These results are then used to recommend modifications to the spacecraft design and expected crew operations that quantitatively increase crew safety from orbital debris impacts.

  20. Modification of an impulse-factoring orbital transfer technique to account for orbit determination and maneuver execution errors

    NASA Technical Reports Server (NTRS)

    Kibler, J. F.; Green, R. N.; Young, G. R.; Kelly, M. G.

    1974-01-01

    A method has previously been developed to satisfy terminal rendezvous and intermediate timing constraints for planetary missions involving orbital operations. The method uses impulse factoring in which a two-impulse transfer is divided into three or four impulses which add one or two intermediate orbits. The periods of the intermediate orbits and the number of revolutions in each orbit are varied to satisfy timing constraints. Techniques are developed to retarget the orbital transfer in the presence of orbit-determination and maneuver-execution errors. Sample results indicate that the nominal transfer can be retargeted with little change in either the magnitude (Delta V) or location of the individual impulses. Additonally, the total Delta V required for the retargeted transfer is little different from that required for the nominal transfer. A digital computer program developed to implement the techniques is described.

  1. Radioisotope Electric Propulsion Missions Utilizing a Common Spacecraft Design

    NASA Technical Reports Server (NTRS)

    Fiehler, Douglas; Oleson, Steven

    2004-01-01

    A study was conducted that shows how a single Radioisotope Electric Propulsion (REP) spacecraft design could be used for various missions throughout the solar system. This spacecraft design is based on a REP feasibility design from a study performed by NASA Glenn Research Center and the Johns Hopkins University Applied Physics Laboratory. The study also identifies technologies that need development to enable these missions. The mission baseline for the REP feasibility design study is a Trojan asteroid orbiter. This mission sends an REP spacecraft to Jupiter s leading Lagrange point where it would orbit and examine several Trojan asteroids. The spacecraft design from the REP feasibility study would also be applicable to missions to the Centaurs, and through some change of payload configuration, could accommodate a comet sample-return mission. Missions to small bodies throughout the outer solar system are also within reach of this spacecraft design. This set of missions, utilizing the common REP spacecraft design, is examined and required design modifications for specific missions are outlined.

  2. Autonomous medical care for exploration class space missions.

    PubMed

    Hamilton, Douglas; Smart, Kieran; Melton, Shannon; Polk, James D; Johnson-Throop, Kathy

    2008-04-01

    The US-based health care system of the International Space Station contains several subsystems, the Health Maintenance System, Environmental Health System and the Countermeasure System. These systems are designed to provide primary, secondary and tertiary medical prevention strategies. The medical system deployed in low Earth orbit for the International Space Station is designed to support a "stabilize and transport" concept of operations. In this paradigm, an ill or injured crewmember would be rapidly evacuated to a definitive medical care facility (DMCF) on Earth, rather than being treated for a protracted period on orbit. The medical requirements of the short (7 day) and long duration (up to 6 months) exploration class missions to the moon are similar to low Earth orbit class missions but also include an additional 4 to 5 days needed to transport an ill or injured crewmember to a DMCF on Earth. Mars exploration class missions are quite different in that they will significantly delay or prevent the return of an ill or injured crewmember to a DMCF. In addition the limited mass, power and volume afforded to medical care will prevent the mission designers from manifesting the entire capability of terrestrial care. National Aeronautics and Space Administration has identified five levels of care as part of its approach to medical support of future missions including the Constellation program. To implement an effective medical risk mitigation strategy for exploration class missions, modifications to the current suite of space medical systems may be needed, including new crew medical officer training methods, treatment guidelines, diagnostic and therapeutic resources, and improved medical informatics.

  3. Data Concentrator

    NASA Technical Reports Server (NTRS)

    Willett, Mike

    2015-01-01

    Orbital Research, Inc., developed, built, and tested three high-temperature components for use in the design of a data concentrator module in distributed turbine engine control. The concentrator receives analog and digital signals related to turbine engine control and communicates with a full authority digital engine control (FADEC) or high-level command processor. This data concentrator follows the Distributed Engine Controls Working Group (DECWG) roadmap for turbine engine distributed controls communication development that operates at temperatures at least up to 225 C. In Phase I, Orbital Research developed detailed specifications for each component needed for the system and defined the total system specifications. This entailed a combination of system design, compiling existing component specifications, laboratory testing, and simulation. The results showed the feasibility of the data concentrator. Phase II of this project focused on three key objectives. The first objective was to update the data concentrator design modifications from DECWG and prime contractors. Secondly, the project defined requirements for the three new high-temperature, application-specific integrated circuits (ASICs): one-time programmable (OTP), transient voltage suppression (TVS), and 3.3V. Finally, the project validated each design by testing over temperature and under load.

  4. Cryogenic On-Orbit Liquid Depot-Storage, Acquisition and Transfer (COLD-SAT) Experiment Conceptual Design and Feasibility Study

    NASA Technical Reports Server (NTRS)

    Kramer, Edward (Editor)

    1998-01-01

    The cryogenic fluid management technologies required for the exploration of the solar system can only be fully developed via space-based experiments. A dedicated spacecraft is the most efficient way to perform these experiments. This report documents the extended conceptual design of the COLD-SAT spacecraft, capable of meeting these experimental requirements. All elements, including the spacecraft, ground segment, launch site modifications and launch vehicle operations, and flight operations are included. Greatly expanded coverage is provided for those areas unique to this cryogenic spacecraft, such as the experiment system, attitude control system, and spacecraft operations. Supporting analyses are included as are testing requirements, facilities surveys, and proposed project timelines.

  5. Acousto-optic signature analysis for inspection of the orbiter thermal protection tile bonds

    NASA Technical Reports Server (NTRS)

    Rodriguez, Julio G.; Tow, D. M.; Barna, B. A.

    1990-01-01

    The goal of this research is to develop a viable NDE technique for the inspection of orbiter thermal protection system (TPS) tile bonds. Phase 2, discussed here, concentrated on developing an empirical understanding of the bonded and unbonded vibration signatures of acreage tiles. Controlled experiments in the laboratory have provided useful information on the dynamic response of TPS tiles. It has been shown that several signatures are common to all the pedigree tiles. This degree of consistency in the tile-SIP (strain isolation pad) dynamic response proves that an unbond can be detected for a known tile and establish the basis for extending the analysis capability to arbitrary tiles for which there are no historical data. The field tests of the noncontacting laser acoustic sensor system, conducted at the Kennedy Space Center (KSC), investigated the vibrational environment of the Orbiter Processing Facility (OPF) and its effect on the measurement and analysis techniques being developed. The data collected showed that for orbiter locations, such as the body flap and elevon, the data analysis scheme, and/or the sensor, will require modification to accommodate the ambient motion. Several methods were identified for accomplishing this, and a solution is seen as readily achievable. It was established that the tile response was similar to that observed in the laboratory. Of most importance, however, is that the field environment will not affect the physics of the dynamic response that is related to bond condition. All of this information is fundamental to any future design and development of a prototype system.

  6. OASIS - ORBIT ANALYSIS AND SIMULATION SOFTWARE

    NASA Technical Reports Server (NTRS)

    Wu, S. C.

    1994-01-01

    The Orbit Analysis and Simulation Software, OASIS, is a software system developed for covariance and simulation analyses of problems involving earth satellites, especially the Global Positioning System (GPS). It provides a flexible, versatile and efficient accuracy analysis tool for earth satellite navigation and GPS-based geodetic studies. To make future modifications and enhancements easy, the system is modular, with five major modules: PATH/VARY, REGRES, PMOD, FILTER/SMOOTHER, and OUTPUT PROCESSOR. PATH/VARY generates satellite trajectories. Among the factors taken into consideration are: 1) the gravitational effects of the planets, moon and sun; 2) space vehicle orientation and shapes; 3) solar pressure; 4) solar radiation reflected from the surface of the earth; 5) atmospheric drag; and 6) space vehicle gas leaks. The REGRES module reads the user's input, then determines if a measurement should be made based on geometry and time. PMOD modifies a previously generated REGRES file to facilitate various analysis needs. FILTER/SMOOTHER is especially suited to a multi-satellite precise orbit determination and geodetic-type problems. It can be used for any situation where parameters are simultaneously estimated from measurements and a priori information. Examples of nonspacecraft areas of potential application might be Very Long Baseline Interferometry (VLBI) geodesy and radio source catalogue studies. OUTPUT PROCESSOR translates covariance analysis results generated by FILTER/SMOOTHER into user-desired easy-to-read quantities, performs mapping of orbit covariances and simulated solutions, transforms results into different coordinate systems, and computes post-fit residuals. The OASIS program was developed in 1986. It is designed to be implemented on a DEC VAX 11/780 computer using VAX VMS 3.7 or higher. It can also be implemented on a Micro VAX II provided sufficient disk space is available.

  7. Design and Implementation of the Boundary Layer Transition Flight Experiment on Space Shuttle Discovery

    NASA Technical Reports Server (NTRS)

    Spanos, Theodoros A.; Micklos, Ann

    2010-01-01

    In an effort to better the understanding of high speed aerodynamics, a series of flight experiments were installed on Space Shuttle Discovery during the STS-119 and STS-128 missions. This experiment, known as the Boundary Layer Transition Flight Experiment (BLTFE), provided the technical community with actual entry flight data from a known height protuberance at Mach numbers at and above Mach 15. Any such data above Mach 15 is irreproducible in a laboratory setting. Years of effort have been invested in obtaining this valuable data, and many obstacles had to be overcome in order to ensure the success of implementing an Orbiter modification. Many Space Shuttle systems were involved in the installation of appropriate components that revealed 'concurrent engineering' was a key integration tool. This allowed the coordination of all various parts and pieces which had to be sequenced appropriately and installed at the right time. Several issues encountered include Orbiter configuration and access, design requirements versus current layout, implementing the modification versus typical processing timelines, and optimizing the engineering design cycles and changes. Open lines of communication within the entire modification team were essential to project success as the team was spread out across the United States, from NASA Kennedy Space Center in Florida, to NASA Johnson Space Center in Texas, to Boeing Huntington Beach, California among others. The forum permits the discussion of processing concerns from the design phase to the implementation phase, which eventually saw the successful flights and data acquisition on STS-119 in March 2009 and on STS-128 in September 2009.

  8. The effect of runway surface and braking on Shuttle Orbiter main gear tire wear

    NASA Technical Reports Server (NTRS)

    Daugherty, Robert H.; Stubbs, Sandy M.

    1992-01-01

    In 1988, a 1067 m long touchdown zone on each end of the Kennedy Space Center (KSC) Shuttle Landing Facility (SLF) was modified from its original heavy-broom finish with transverse grooves configuration to a longitudinal corduroy surface texture with no transverse grooves. The intent of this modification was to reduce the spin-up wear on the Orbiter main gear tires and provide for somewhat higher crosswind capabilities at that site. The modification worked well, so it was proposed that the remainder of the runway be modified as well to permit even higher crosswind landing capability. Tests were conducted at the NASA Langley Aircraft Landing Dynamics Facility (ALDF) to evaluate the merit of such a modification. This paper discusses the results of these tests, and explains why the proposed modification did not provide the expected improvement and thus was not implemented. Also, in an ongoing program to evaluate the origin of various tire wear phenomenon, a series of tests was conducted to evaluate the effect of braking on tire wear. Finally, a modified tire is discussed in terms of its wear performance under rollout and braking operations.

  9. Numerical orbit generators of artificial earth satellites

    NASA Astrophysics Data System (ADS)

    Kugar, H. K.; Dasilva, W. C. C.

    1984-04-01

    A numerical orbit integrator containing updatings and improvements relative to the previous ones that are being utilized by the Departmento de Mecanica Espacial e Controle (DMC), of INPE, besides incorporating newer modellings resulting from the skill acquired along the time is presented. Flexibility and modularity were taken into account in order to allow future extensions and modifications. Characteristics of numerical accuracy, processing quickness, memory saving as well as utilization aspects were also considered. User's handbook, whole program listing and qualitative analysis of accuracy, processing time and orbit perturbation effects were included as well.

  10. Evaluation of semiempirical atmospheric density models for orbit determination applications

    NASA Technical Reports Server (NTRS)

    Cox, C. M.; Feiertag, R. J.; Oza, D. H.; Doll, C. E.

    1994-01-01

    This paper presents the results of an investigation of the orbit determination performance of the Jacchia-Roberts (JR), mass spectrometer incoherent scatter 1986 (MSIS-86), and drag temperature model (DTM) atmospheric density models. Evaluation of the models was performed to assess the modeling of the total atmospheric density. This study was made generic by using six spacecraft and selecting time periods of study representative of all portions of the 11-year cycle. Performance of the models was measured for multiple spacecraft, representing a selection of orbit geometries from near-equatorial to polar inclinations and altitudes from 400 kilometers to 900 kilometers. The orbit geometries represent typical low earth-orbiting spacecraft supported by the Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD). The best available modeling and orbit determination techniques using the Goddard Trajectory Determination System (GTDS) were employed to minimize the effects of modeling errors. The latest geopotential model available during the analysis, the Goddard earth model-T3 (GEM-T3), was employed to minimize geopotential model error effects on the drag estimation. Improved-accuracy techniques identified for TOPEX/Poseidon orbit determination analysis were used to improve the Tracking and Data Relay Satellite System (TDRSS)-based orbit determination used for most of the spacecraft chosen for this analysis. This paper shows that during periods of relatively quiet solar flux and geomagnetic activity near the solar minimum, the choice of atmospheric density model used for orbit determination is relatively inconsequential. During typical solar flux conditions near the solar maximum, the differences between the JR, DTM, and MSIS-86 models begin to become apparent. Time periods of extreme solar activity, those in which the daily and 81-day mean solar flux are high and change rapidly, result in significant differences between the models. During periods of high geomagnetic activity, the standard JR model was outperformed by DTM. Modification of the JR model to use a geomagnetic heating delay of 3 hours, as used in DTM, instead of the 6.7-hour delay produced results comparable to or better than the DTM performance, reducing definitive orbit solution ephermeris overlap differences by 30 to 50 percent. The reduction in the overlap differences would be useful for mitigating the impact of geomagnetic storms on orbit prediction.

  11. Universal relations for spin-orbit-coupled Fermi gas near an s -wave resonance

    NASA Astrophysics Data System (ADS)

    Zhang, Pengfei; Sun, Ning

    2018-04-01

    Synthetic spin-orbit-coupled quantum gases have been widely studied both experimentally and theoretically in the past decade. As shown in previous studies, this modification of single-body dispersion will in general couple different partial waves of the two-body scattering and thus distort the wave function of few-body bound states which determines the short-distance behavior of many-body wave function. In this work, we focus on the two-component Fermi gas with one-dimensional or three-dimensional spin-orbit coupling (SOC) near an s -wave resonance. Using the method of effective field theory and the operator product expansion, we derive universal relations for both systems, including the adiabatic theorem, viral theorem, and pressure relation, and obtain the momentum distribution matrix 〈ψa†(q ) ψb(q ) 〉 at large q (a ,b are spin indices). The momentum distribution matrix shows both spin-dependent and spatial anisotropic features. And the large momentum tail is modified at the subleading order thanks to the SOC. We also discuss the experimental implication of these results depending on the realization of the SOC.

  12. Three Orbital Burns to Molniya Orbit Via Shuttle_Centaur G Upper Stage

    NASA Technical Reports Server (NTRS)

    Williams, Craig H.

    2015-01-01

    An unclassified analytical trajectory design, performance, and mission study was done for the 1982 to 1986 joint National Aeronautics and Space Administration (NASA)-United States Air Force (USAF) Shuttle/Centaur G upper stage development program to send performance-demanding payloads to high orbits such as Molniya using an unconventional orbit transfer. This optimized three orbital burn transfer to Molniya orbit was compared to the then-baselined two burn transfer. The results of the three dimensional trajectory optimization performed include powered phase steering data and coast phase orbital element data. Time derivatives of the orbital elements as functions of thrust components were evaluated and used to explain the optimization's solution. Vehicle performance as a function of parking orbit inclination was given. Performance and orbital element data was provided for launch windows as functions of launch time. Ground track data was given for all burns and coasts including variation within the launch window. It was found that a Centaur with fully loaded propellant tanks could be flown from a 37 deg inclination low Earth parking orbit and achieve Molniya orbit with comparable performance to the baselined transfer which started from a 57 deg inclined orbit: 9,545 versus 9,552 lb of separated spacecraft weight, respectively. There was a significant reduction in the need for propellant launch time reserve for a 1 hr window: only 78 lb for the three burn transfer versus 320 lb for the two burn transfer. Conversely, this also meant that longer launch windows over more orbital revolutions could be done for the same amount of propellant reserve. There was no practical difference in ground tracking station or airborne assets needed to secure telemetric data, even though the geometric locations of the burns varied considerably. There was a significant adverse increase in total mission elapsed time for the three versus two burn transfer (12 vs. 1-1/4 hr), but could be accommodated by modest modifications to Centaur systems. Future applications were discussed. The three burn transfer was found to be a viable, arguably preferable, alternative to the two burn transfer.

  13. Three Orbital Burns to Molniya Orbit via Shuttle Centaur G Upper Stage

    NASA Technical Reports Server (NTRS)

    Williams, Craig H.

    2014-01-01

    An unclassified analytical trajectory design, performance, and mission study was done for the 1982-86 joint NASA-USAF Shuttle/Centaur G upper stage development program to send performance-demanding payloads to high orbits such as Molniya using an unconventional orbit transfer. This optimized three orbital burn transfer to Molniya orbit was compared to the then-baselined two burn transfer. The results of the three dimensional trajectory optimization performed include powered phase steering data and coast phase orbital element data. Time derivatives of the orbital elements as functions of thrust components were evaluated and used to explain the optimization's solution. Vehicle performance as a function of parking orbit inclination was given. Performance and orbital element data was provided for launch windows as functions of launch time. Ground track data was given for all burns and coasts including variation within the launch window. It was found that a Centaur with fully loaded propellant tanks could be flown from a 37deg inclination low Earth parking orbit and achieve Molniya orbit with comparable performance to the baselined transfer which started from a 57deg inclined orbit: 9,545 lb vs. 9,552 lb of separated spacecraft weight respectively. There was a significant reduction in the need for propellant launch time reserve for a one hour window: only 78 lb for the three burn transfer vs. 320 lb for the two burn transfer. Conversely, this also meant that longer launch windows over more orbital revolutions could be done for the same amount of propellant reserve. There was no practical difference in ground tracking station or airborne assets needed to secure telemetric data, even though the geometric locations of the burns varied considerably. There was a significant adverse increase in total mission elapsed time for the three vs. two burn transfer (12 vs. 11/4 hrs), but could be accommodated by modest modifications to Centaur systems. Future applications were discussed. The three burn transfer was found to be a viable, arguably preferable, alternative to the two burn transfer.

  14. Gender-Based Differences in Outcomes After Orbital Atherectomy for the Treatment of De Novo Severely Calcified Coronary Lesions.

    PubMed

    Lee, Michael S; Shlofmitz, Evan; Mansourian, Pejman; Sethi, Sanjum; Shlofmitz, Richard A

    2016-11-01

    We evaluated the relationship between gender and angiographic and clinical outcomes in patients with severely calcified lesions who underwent orbital atherectomy. Female gender is associated with increased risk of adverse clinical events after percutaneous coronary intervention (PCI). Severe coronary artery calcification increases the complexity of PCI and increases the risk of adverse cardiac events. Orbital atherectomy is effective in plaque modification, which facilitates stent delivery and expansion. Whether gender differences exist after orbital atherectomy is unclear. Our analysis retrospectively analyzed 458 consecutive real-world patients (314 males and 144 females) from three centers who underwent orbital atherectomy. The primary endpoint was the major adverse cardiac and cerebrovascular event (MACCE) rate, defined as the composite of death, myocardial infarction (MI), target-vessel revascularization (TVR), and stroke, at 30 days. The primary endpoint of MACCE was low and similar in females and males (0.7% vs 2.9%; P=.14). The individual endpoints of death (0.7% vs 1.6%; P=.43), MI (0.7% vs 1.3%; P=.58), TVR (0% vs 0%; P>.99), and stroke (0% vs 0.3%; P=.50) were low in both groups and did not differ. Angiographic complications were low: perforation (0.8% vs 0.7%; P>.90), dissection (0.8% vs 1.1%; P=.80), and no-reflow (0.8% vs 0.7%; P>.90). Plaque modification with orbital atherectomy was safe and provided similar angiographic and clinical outcomes between females and males. Randomized trials with longer-term follow-up are needed to support our results.

  15. Tethered Satellite System (TSS-1R)-Post Flight (STS-75) Engineering Performance Report

    NASA Technical Reports Server (NTRS)

    Lavoie, Anthony R.

    1996-01-01

    The first mission of the Tethered Satellite deployer was flown onboard Atlantis in 1992 during the Space Transportation System (STS) flight STS-46. Due to a mechanical interference with the level wind mechanism the satellite was only Deployed to 256 m rather than the planned 20,000 m. Other problems were also experienced during the STS-46 flight and several modifications were made to the Deployer and Satellite. STS-75 was a reflight of the Tethered Satellite System 1 (TSS-1) designated as Tethered Satellite System 1 Reflight (TSS-1 R) onboard Columbia. As on STS-46, the TSS payload consisted of the Deployer, the Satellite, 3 cargo bay mounted experiments: Shuttle Electrodynamic Tether System (SETS), Shuttle Potential and Return Electron Experiment (SPREE), Deployer Core Equipment (DCORE) 4 Satellite mounted experiments: Research on Electrodynamics Tether Effects (RETE), Research on Orbital Plasma Electrodynamics (ROPE), Satellite Core Instruments (SCORE), Tether Magnetic Field Experiment (TEMAG) and an aft flight deck camera: Tether Optical Phenomena Experiment (TOP). Following successful pre-launch, launch and pre-deployment orbital operations, the Deployer deployed the Tethered Satellite to 19,695 m at which point the tether broke within the Satellite Deployment Boom (SDB). The planned length for On-Station I (OST1) was 20,700 m The Satellite flew away from the Orbiter with the tether attached. The satellite was "safed" and placed in a limited power mode via the RF link. The Satellite was contacted periodically during overflights of ground stations. Cargo bay science activities continued for the period of time allocated to TSS-1 R operations.

  16. Payload/orbiter contamination control requirement study: Spacelab configuration contamination study

    NASA Technical Reports Server (NTRS)

    Bareiss, L. E.; Hetrick, M. A.; Ress, E. B.; Strange, D. A.

    1976-01-01

    The assessment of the Spacelab carrier induced contaminant environment was continued, and the ability of Spacelab to meet established contamination control criteria for the space transportation system program was determined. The primary areas considered included: (1) updating, refining, and improving the Spacelab contamination computer model and contamination analysis methodology, (2) establishing the resulting adjusted induced environment predictions for comparison with the applicable criteria, (3) determining the Spacelab design and operational requirements necessary to meet the criteria, (4) conducting mission feasibility analyses of the combined Spacelab/Orbiter contaminant environment for specific proposed mission and payload mixes, and (5) establishing a preliminary Spacelab mission support plan as well as model interface requirements; A summary of those activities conducted to date with respect to the modelling, analysis, and predictions of the induced environment, including any modifications in approach or methodology utilized in the contamination assessment of the Spacelab carrier, was presented.

  17. Space shuttle: Aerodynamic stability and control characteristics of the NASA/MSC .006 scale 040-A delta wing orbiter

    NASA Technical Reports Server (NTRS)

    Click, P. L.; Michana, D. J.; Sarver, D. A.

    1971-01-01

    Experimental aerodynamic investigations were made on a .006 scale model 040-A delta wing space shuttle orbiter configuration. These tests were conducted to determine six-degree-of-freedom force and moment data for preliminary stability and control analysis. Data were obtained over a Mach number range from 0.6 to 4.96 at angles of attack from -10 deg to 50 deg at zero degrees sideslip and at angles of sideslip from -10 deg to 10 deg at constants angles of attack of 0 deg, 15 deg, 30 deg, and 45 deg. Various aileron, elevator, (elevon) rudder and rudder flare deflection angles were tested to establish the control effectiveness and vehicle stability. Model component buildup data were also obtained to provide a data base for future configuration modifications. Plotted data results are presented in both the body and stability axis system.

  18. The dynamics and control of large flexible space structures, 6

    NASA Technical Reports Server (NTRS)

    Bainum, P. M.

    1983-01-01

    The controls analysis based on a truncated finite element model of the 122m. Hoop/Column Antenna System focuses on an analysis of the controllability as well as the synthesis of control laws. Graph theoretic techniques are employed to consider controllability for different combinations of number and locations of actuators. Control law synthesis is based on an application of the linear regulator theory as well as pole placement techniques. Placement of an actuator on the hoop can result in a noticeable improvement in the transient characteristics. The problem of orientation and shape control of an orbiting flexible beam, previously examined, is now extended to include the influence of solar radiation environmental forces. For extremely flexible thin structures modification of control laws may be required and techniques for accomplishing this are explained. Effects of environmental torques are also included in previously developed models of orbiting flexible thin platforms.

  19. Space shuttle with common fuel tank for liquid rocket booster and main engines (supertanker space shuttle)

    NASA Technical Reports Server (NTRS)

    Thorpe, Douglas G.

    1991-01-01

    An operation and schedule enhancement is shown that replaces the four-body cluster (Space Shuttle Orbiter (SSO), external tank, and two solid rocket boosters) with a simpler two-body cluster (SSO and liquid rocket booster/external tank). At staging velocity, the booster unit (liquid-fueled booster engines and vehicle support structure) is jettisoned while the remaining SSO and supertank continues on to orbit. The simpler two-bodied cluster reduces the processing and stack time until SSO mate from 57 days (for the solid rocket booster) to 20 days (for the liquid rocket booster). The areas in which liquid booster systems are superior to solid rocket boosters are discussed. Alternative and future generation vehicles are reviewed to reveal greater performance and operations enhancements with more modifications to the current methods of propulsion design philosophy, e.g., combined cycle engines, and concentric propellant tanks.

  20. STS-92 - Shuttle Carrier Aircraft (SCA)

    NASA Image and Video Library

    2000-10-29

    One of NASA’s two modified Boeing 747 Shuttle Carrier Aircraft is bathed in the morning Sun at NASA’s Dryden Flight Research Center at Edwards, California. The modified jumbo jetliners are used to ferry the Space Shuttle orbiters between Dryden and the Kennedy Space Center in Florida and Boeing’s Reusable Space Systems modification facility at Palmdale, California. Features which distinguish the two SCAs from standard 747 jetliners are three struts, with associated interior structural strengthening, which protrude from the top of the fuselage (two aft, one forward) on which the orbiter is attached, and two additional vertical stabilizers, one on each end of the standard horizontal stabilizer, to enhance directional stability. All interior furnishings and equipment aft of the forward No. 1 doors have also been removed to reduce weight. The two SCAs are under the operational control of NASA's Johnson Space Center, Houston, Texas.

  1. Conceptual Design, Feasibility and Payoff Analysis of a Third Stage for EELV

    DTIC Science & Technology

    2014-06-01

    the overall vehicle architecture, identifying locations for modification or stage shape. Trade studies of various propellant types (LOX/ LH2 , LOX/RP...or stage shape. Trade studies of various propellant types (LOX/ LH2 , LOX/RP, LOX/methane, hydrazine monopropellant) were included in the analysis...Geostationary transfer orbit Isp = Specific impulse LEO = Low Earth Orbit LOX = Liquid oxygen LH2 = Liquid hydrogen POST = Program to

  2. Orbital transfer vehicle engine technology: Baffled injector design, fabrication, and verification

    NASA Technical Reports Server (NTRS)

    Schneider, J. A.

    1991-01-01

    New technologies for space-based, reusable, throttleable, cryogenic orbit transfer propulsion are being evaluated. Supporting tasks for the design of a dual expander cycle engine thrust chamber design are documented. The purpose of the studies was to research the materials used in the thrust chamber design, the supporting fabrication methods necessary to complete the design, and the modification of the injector element for optimum injector/chamber compatibility.

  3. Comparison of simulated heat transport in NSTX via high frequency Alfvén eigenmode-induced electron orbit modification with TRANSP power balance modeling

    NASA Astrophysics Data System (ADS)

    Crocker, N. A.; Tritz, K.; White, R. B.; Fredrickson, E. D.; Gorelenkov, N. N.; NSTX-U Team

    2016-10-01

    Compressional (CAE) and global (GAE) AEs have been hypothesized to cause an anomalously high electron thermal diffusivity (χe) routinely inferred via TRANSP power balance modeling in the core (r / a < 0.3) of NSTX beam heated plasmas. New simulations with the guiding-center code ORBIT test a leading proposed transport mechanism: electron orbit stochastization by multiple modes. Simulations with a set of modes identified as GAEs in a high performance, beam heated plasma-using experimentally determined amplitudes, frequencies and wave numbers-yield a χe insufficient to match TRANSP. To produce a comparable χe, the amplitudes must be increased by a factor of 10, which is outside the bounds of measurement uncertainty. Many observed modes, identified as CAEs, could not be included without modifications to ORBIT. These are in progress. However, given the uncertainties in identification, it is informative to calculate χe assuming all the observed modes are GAEs. This leads to substantially higher χe, although an amplitude increase by a factor > 3 is still necessary to match TRANSP. Supported by US DOE Contracts DE-SC0011810, DE-FG02-99ER54527 and DE-AC02-09CH11466.

  4. Results of an aerodynamic investigation of a space shuttle orbiter/747 carrier vehicle configuration to establish a free-stream data base for ALT separation investigations, utilizing a 0.0125-scale model (48-0/AX1318I-1) in the ARC 14-foot wind tunnel (CA23A)

    NASA Technical Reports Server (NTRS)

    Gillins, R. L.

    1975-01-01

    Force and moment data are presented which were obtained for each vehicle separately at a Mach number of 0.6, and for the mated orbiter/747 configuration at Mach numbers of 0.3, 0.5, 0.6, and 0.7. Orbiter angles of attack from 0 degrees to +12 degrees and 747/Carrier angles of attack from -3 degrees to +7 degrees were investigated at angles of sideslip of 0 degrees and -5 degrees. Model variables include orbiter elevon and rudder deflections, orbiter tail cone-on and off, various orbiter/747 attach structure configurations, 747 stabilizer and rudder deflections, and 747 CAM modification components-on and off. Photographs of test configurations are included.

  5. Orbit Determination and Navigation of the Solar Terrestrial Relations Observatory (STEREO)

    NASA Technical Reports Server (NTRS)

    Mesarch, Michael A.; Robertson, Mika; Ottenstein, Neil; Nicholson, Ann; Nicholson, Mark; Ward, Douglas T.; Cosgrove, Jennifer; German, Darla; Hendry, Stephen; Shaw, James

    2007-01-01

    This paper provides an overview of the required upgrades necessary for navigation of NASA's twin heliocentric science missions, Solar TErestrial RElations Observatory (STEREO) Ahead and Behind. The orbit determination of the STEREO spacecraft was provided by the NASA Goddard Space Flight Center's (GSFC) Flight Dynamics Facility (FDF) in support of the mission operations activities performed by the Johns Hopkins University Applied Physics Laboratory (APL). The changes to FDF's orbit determination software included modeling upgrades as well as modifications required to process the Deep Space Network X-band tracking data used for STEREO. Orbit results as well as comparisons to independently computed solutions are also included. The successful orbit determination support aided in maneuvering the STEREO spacecraft, launched on October 26, 2006 (00:52 Z), to target the lunar gravity assists required to place the spacecraft into their final heliocentric drift-away orbits where they are providing stereo imaging of the Sun.

  6. Orbit Determination and Navigation of the Solar Terrestrial Relations Observatory (STEREO)

    NASA Technical Reports Server (NTRS)

    Mesarch, Michael; Robertson, Mika; Ottenstein, Neil; Nicholson, Ann; Nicholson, Mark; Ward, Douglas T.; Cosgrove, Jennifer; German, Darla; Hendry, Stephen; Shaw, James

    2007-01-01

    This paper provides an overview of the required upgrades necessary for navigation of NASA's twin heliocentric science missions, Solar TErestrial RElations Observatory (STEREO) Ahead and Behind. The orbit determination of the STEREO spacecraft was provided by the NASA Goddard Space Flight Center's (GSFC) Flight Dynamics Facility (FDF) in support of the mission operations activities performed by the Johns Hopkins University Applied Physics Laboratory (APL). The changes to FDF s orbit determination software included modeling upgrades as well as modifications required to process the Deep Space Network X-band tracking data used for STEREO. Orbit results as well as comparisons to independently computed solutions are also included. The successful orbit determination support aided in maneuvering the STEREO spacecraft, launched on October 26, 2006 (00:52 Z), to target the lunar gravity assists required to place the spacecraft into their final heliocentric drift-away orbits where they are providing stereo imaging of the Sun.

  7. Navigation strategy and filter design for solar electric missions

    NASA Technical Reports Server (NTRS)

    Tapley, B. D.; Hagar, H., Jr.

    1972-01-01

    Methods which have been proposed to improve the navigation accuracy for the low-thrust space vehicle include modifications to the standard Sequential- and Batch-type orbit determination procedures and the use of inertial measuring units (IMU) which measures directly the acceleration applied to the vehicle. The navigation accuracy obtained using one of the more promising modifications to the orbit determination procedures is compared with a combined IMU-Standard. The unknown accelerations are approximated as both first-order and second-order Gauss-Markov processes. The comparison is based on numerical results obtained in a study of the navigation requirements of a numerically simulated 152-day low-thrust mission to the asteroid Eros. The results obtained in the simulation indicate that the DMC algorithm will yield a significant improvement over the navigation accuracies achieved with previous estimation algorithms. In addition, the DMC algorithms will yield better navigation accuracies than the IMU-Standard Orbit Determination algorithm, except for extremely precise IMU measurements, i.e., gyroplatform alignment .01 deg and accelerometer signal-to-noise ratio .07. Unless these accuracies are achieved, the IMU navigation accuracies are generally unacceptable.

  8. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, Jingcheng; Wang, Yu; Li, Bin, E-mail: libin@mail.ustc.edu.cn, E-mail: bwang@ustc.edu.cn

    We investigate the modification of electronic properties of single cobalt phthalocyanine (CoPc) molecule by an extra Co atom co-adsorbed on Au (111) surface using scanning tunneling microscopy (STM), joint with density functional theory (DFT) calculations. By manipulating CoPc molecules using the STM tip to contact individually adsorbed Co atom, two types of relatively stable complexes can be formed, denoted as CoPc-Co(I) and CoPc-Co(II). In CoPc-Co(I), the Co atom is at an intramolecular site close to aza-N atom of CoPc, which induces significant modifications of the electronic states of CoPc, such as energy shifts and splitting of nonlocal molecular orbitals. However,more » in CoPc-Co(II) where the Co atom is underneath a benzene lobe of CoPc, it only slightly modifies the electronic states of CoPc, and mainly local characteristics of specific molecular orbitals are affected, even though CoPc-Co(II) is more stable than CoPc-Co(I). Our DFT calculations give consistent results with the experiments, and related analyses based on the molecular orbital theory reveal mechanism behind the experimental observations.« less

  9. Space Shuttle Orbiter windshield bird impact analysis

    NASA Technical Reports Server (NTRS)

    Edelstein, Karen S.; Mccarty, Robert E.

    1988-01-01

    The NASA Space Shuttle Orbiter's windshield employs three glass panes separated by air gaps. The brittleness of the glass offers much less birdstrike energy-absorption capability than the laminated polycarbonate windshields of more conventional aircraft; attention must accordingly be given to the risk of catastrophic bird impact, and to methods of strike prevention that address bird populations around landing sites rather than the modification of the window's design. Bird populations' direct reduction, as well as careful scheduling of Orbiter landing times, are suggested as viable alternatives. The question of birdstrike-resistant glass windshield design for hypersonic aerospacecraft is discussed.

  10. Proposed Facility Modifications to Support Propulsion Systems Testing Under Simulated Space Conditions at Plum Brook Station's Spacecraft Propulsion Research Facility (B-2)

    NASA Technical Reports Server (NTRS)

    Edwards, Daryl A.

    2008-01-01

    Preparing NASA's Plum Brook Station's Spacecraft Propulsion Research Facility (B-2) to support NASA's new generation of launch vehicles has raised many challenges for B-2's support staff. The facility provides a unique capability to test chemical propulsion systems/vehicles while simulating space thermal and vacuum environments. Designed and constructed in the early 1960s to support upper stage cryogenic engine/vehicle system development, the Plum Brook Station B-2 facility will require modifications to support the larger, more powerful, and more advanced engine systems for the next generation of vehicles leaving earth's orbit. Engine design improvements over the years have included large area expansion ratio nozzles, greater combustion chamber pressures, and advanced materials. Consequently, it has become necessary to determine what facility changes are required and how the facility can be adapted to support varying customers and their specific test needs. Exhaust system performance, including understanding the present facility capabilities, is the primary focus of this work. A variety of approaches and analytical tools are being employed to gain this understanding. This presentation discusses some of the challenges in applying these tools to this project and expected facility configuration to support the varying customer needs.

  11. Texture Modification of the Shuttle Landing Facility Runway at the NASA Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Daugherty, Robert H.; Yager, Thomas J.

    1996-01-01

    This paper describes the test procedures and the selection criteria used in selecting the best runway surface texture modification at the Kennedy Space Center (KSC) Shuttle Landing Facility (SLF) to reduce Orbiter tire wear. The new runway surface may ultimately result in an increase of allowable crosswinds for launch and landing operations. The modification allows launch and landing operations in 20-kt crosswinds if desired. This 5-kt increase over the previous 15-kt limit drastically increases landing safety and the ability to make on-time launches to support missions where space station rendezvous is planned.

  12. Can the second order multireference perturbation theory be considered a reliable tool to study mixed-valence compounds?

    PubMed

    Pastore, Mariachiara; Helal, Wissam; Evangelisti, Stefano; Leininger, Thierry; Malrieu, Jean-Paul; Maynau, Daniel; Angeli, Celestino; Cimiraglia, Renzo

    2008-05-07

    In this paper, the problem of the calculation of the electronic structure of mixed-valence compounds is addressed in the frame of multireference perturbation theory (MRPT). Using a simple mixed-valence compound (the 5,5(') (4H,4H('))-spirobi[ciclopenta[c]pyrrole] 2,2('),6,6(') tetrahydro cation), and the n-electron valence state perturbation theory (NEVPT2) and CASPT2 approaches, it is shown that the ground state (GS) energy curve presents an unphysical "well" for nuclear coordinates close to the symmetric case, where a maximum is expected. For NEVPT, the correct shape of the energy curve is retrieved by applying the MPRT at the (computationally expensive) third order. This behavior is rationalized using a simple model (the ionized GS of two weakly interacting identical systems, each neutral system being described by two electrons in two orbitals), showing that the unphysical well is due to the canonical orbital energies which at the symmetric (delocalized) conformation lead to a sudden modification of the denominators in the perturbation expansion. In this model, the bias introduced in the second order correction to the energy is almost entirely removed going to the third order. With the results of the model in mind, one can predict that all MRPT methods in which the zero order Hamiltonian is based on canonical orbital energies are prone to present unreasonable energy profiles close to the symmetric situation. However, the model allows a strategy to be devised which can give a correct behavior even at the second order, by simply averaging the orbital energies of the two charge-localized electronic states. Such a strategy is adopted in a NEVPT2 scheme obtaining a good agreement with the third order results based on the canonical orbital energies. The answer to the question reported in the title (is this theoretical approach a reliable tool for a correct description of these systems?) is therefore positive, but care must be exercised, either in defining the orbital energies or by resorting to the third order using for them the standard definition.

  13. Discovery Orbiter Major Modifications

    NASA Image and Video Library

    2003-08-27

    In the Vehicle Assembly Building, Jim Landy, NDE specialist, sets up a flight crew lockers for flash thermography. He is screening the lockers for hidden damage underneath dings and dents that might occur during handling.

  14. Dynamic Characterization of an Inflatable Concentrator for Solar Thermal Propulsion

    NASA Technical Reports Server (NTRS)

    Leigh, Larry; Hamidzadeh, Hamid; Tinker, Michael L.; Rodriguez, Pedro I. (Technical Monitor)

    2001-01-01

    An inflatable structural system that is a technology demonstrator for solar thermal propulsion and other applications is characterized for structural dynamic behavior both experimentally and computationally. The inflatable structure is a pressurized assembly developed for use in orbit to support a Fresnel lens or inflatable lenticular element for focusing sunlight into a solar thermal rocket engine. When the engine temperature reaches a pre-set level, the propellant is injected into the engine, absorbs heat from an exchanger, and is expanded through the nozzle to produce thrust. The inflatable structure is a passively adaptive system in that a regulator and relief valve are utilized to maintain pressure within design limits during the full range of orbital conditions. Modeling and test activities are complicated by the fact that the polyimide film material used for construction of the inflatable is nonlinear, with modulus varying as a function of frequency, temperature, and level of excitation. Modal vibration testing and finite element modeling are described in detail in this paper. The test database is used for validation and modification of the model. This work is highly significant because of the current interest in inflatable structures for space application, and because of the difficulty in accurately modeling such systems.

  15. Orbital Atherectomy Plaque Modification Assessment of the Femoropopliteal Artery Via Intravascular Ultrasound (TRUTH Study)

    PubMed Central

    Zavlunova, Susanna; Attubato, Michael J.; Martinsen, Brad J.; Mintz, Gary S.; Maehara, Akiko

    2015-01-01

    Objective: The Tissue Removal Assessment with Ultrasound of the SFA and Popliteal (TRUTH) study assessed the performance of the orbital atherectomy system (OAS) to treat femoropopliteal arteries, including determining its effect on plaque removal. Methods: Patients with symptomatic femoropopliteal peripheral arterial disease were treated with the OAS followed by adjunctive balloon angioplasty (BA). Intravascular ultrasound (IVUS) images were collected pre- and post-OAS and post-OAS BA. Patients were followed through 12 months post-procedure. Results: Twenty-nine lesions were treated with OAS-BA in 25 patients. The mean maximum balloon inflation pressure was 5.2 ± 1.2 atm. Virtual histology IVUS (VH-IVUS) analysis revealed at the maximum calcium ablation site that calcium reduction was responsible for 86% of the lumen area increase. The minimum lumen area increased from 4.0 mm2 to 9.1 mm2 (<.0001), and the percentage of area stenosis decreased from 76.9% to 43.0% (<.0001) after OAS-BA. At 12 months, the target lesion revascularization rate was 8.2%, and ankle–brachial index and Rutherford classification improved significantly from baseline through follow-up. Conclusion: The VH-IVUS analysis reveals that OAS modifies the calcified component of the plaque burden. It is hypothesized that calcium modification by OAS changes the lesion compliance, allowing for low pressure adjunctive BA. The clinical outcomes were favorable through 12-month follow-up. PMID:26490645

  16. Orbital Atherectomy Plaque Modification Assessment of the Femoropopliteal Artery Via Intravascular Ultrasound (TRUTH Study).

    PubMed

    Babaev, Anvar; Zavlunova, Susanna; Attubato, Michael J; Martinsen, Brad J; Mintz, Gary S; Maehara, Akiko

    2015-10-01

    The Tissue Removal Assessment with Ultrasound of the SFA and Popliteal (TRUTH) study assessed the performance of the orbital atherectomy system (OAS) to treat femoropopliteal arteries, including determining its effect on plaque removal. Patients with symptomatic femoropopliteal peripheral arterial disease were treated with the OAS followed by adjunctive balloon angioplasty (BA). Intravascular ultrasound (IVUS) images were collected pre- and post-OAS and post-OAS BA. Patients were followed through 12 months post-procedure. Twenty-nine lesions were treated with OAS-BA in 25 patients. The mean maximum balloon inflation pressure was 5.2 ± 1.2 atm. Virtual histology IVUS (VH-IVUS) analysis revealed at the maximum calcium ablation site that calcium reduction was responsible for 86% of the lumen area increase. The minimum lumen area increased from 4.0 mm(2) to 9.1 mm(2) (<.0001), and the percentage of area stenosis decreased from 76.9% to 43.0% (<.0001) after OAS-BA. At 12 months, the target lesion revascularization rate was 8.2%, and ankle-brachial index and Rutherford classification improved significantly from baseline through follow-up. The VH-IVUS analysis reveals that OAS modifies the calcified component of the plaque burden. It is hypothesized that calcium modification by OAS changes the lesion compliance, allowing for low pressure adjunctive BA. The clinical outcomes were favorable through 12-month follow-up. © The Author(s) 2015.

  17. Effect of aerodynamic and angle-of-attack uncertainties on the blended entry flight control system of the Space Shuttle from Mach 10 to 2.5

    NASA Technical Reports Server (NTRS)

    Stone, H. W.; Powell, R. W.

    1984-01-01

    A six-degree-of-freedom simulation analysis has been performed for the Space Shuttle Orbiter during entry from Mach 10 to 2.5 with realistic off-nominal conditions using the entry flight control system specified in May 1978. The off-nominal conditions included the following: (1) aerodynamic uncertainties, (2) an error in deriving the angle of attack from onboard instrumentation, (3) the failure of two of the four reaction control-system thrusters on each side, and (4) a lateral center-of-gravity offset. With combinations of the above off-nominal conditions, the control system performed satisfactorily with a few exceptions. The cases that did not exhibit satisfactory performance displayed the following main weaknesses. Marginal performance was exhibited at hypersonic speeds with a sensed angle-of-attack error of 4 deg. At supersonic speeds the system tended to be oscillatory, and the system diverged for several cases because of the inability to hold lateral trim. Several system modifications were suggested to help solve these problems and to maximize safety on the first flight: alter the elevon-trim and speed-brake schedules, delay switching to rudder trim until the rudder effectiveness is adequate, and reduce the overall rudder loop gain. These and other modifications were incorporated in a flight-control-system redesign in May 1979.

  18. Orbit Stability of OSIRIS-REx in the Vicinity of Bennu Using a High-Fidelity Solar Radiation Model

    NASA Technical Reports Server (NTRS)

    Williams, Trevor W.; Hughes, Kyle M.; Mashiku, Alinda K.; Longuski, James M.

    2015-01-01

    Solar radiation pressure is one of the largest perturbing forces on the OSIRISRex trajectory as it orbits the asteroid Bennu. In this work, we investigate how forces due to solar radiation perturb the OSIRIS-REx trajectory in a high-fidelity model. The model accounts for Bennu's non-spherical gravity field, third-body gravity forces from the Sun and Jupiter, as well as solar radiation forces acting on a simplified spacecraft model. Such high-fidelity simulations indicate significant solar radiation pressure perturbations from the nominal orbit. Modifications to the initial design of the nominal orbit are found using a variation of parameters approach that reduce the perturbation in eccentricity by a factor of one-half.

  19. Subanalysis of the CONFIRM Registries: Acute Procedural Outcomes in Claudicant and Critical Limb Ischemia Patients With Varying Levels of Calcification Treated for Peripheral Arterial Disease With Orbital Atherectomy.

    PubMed

    Adams, George L; Das, Tony; Lee, Michael S; Beasley, Robert; Mustapha, Jihad

    2015-11-01

    Patients with peripheral arterial disease (PAD) can be classified into groups based upon the severity of the disease using the Rutherford classification system. This analysis compares the procedural outcomes of PAD patients treated with orbital atherectomy stratified by Rutherford class (1-3 = intermittent claudication; 4-6 = critical limb ischemia [CLI]), and acute angiographic outcomes of these patients stratified by degree of lesion calcification. The CONFIRM registry series was analyzed and included 1697 patients with intermittent claudication (Rutherford class 1-3) and 1320 patients with CLI (Rutherford class 4-6) treated with orbital atherectomy. The composite rate of dissection, perforation, slow-flow, vessel closure, spasm, embolism, and thrombus formation was compared between claudicants and CLI patients with varying degrees of lesion calcification. Patients with CLI were older and had a higher prevalence of diabetes, coronary artery disease, and renal disease (P<.001). Claudicants with moderately/severely calcified lesions had a lower rate of dissection (both non-flow limiting and flow-limiting) than claudicants with mildly/minimally calcified lesions. CLI patients with mildly/minimally calcified lesions had higher rates of embolism and thrombus than CLI patients with moderately/severely calcified lesions. Plaque modification with orbital atherectomy resulted in similar low procedural complication rates in the CLI group compared with the claudicant group. These results suggest that orbital atherectomy is safe and effective for treating calcified lesions in high-risk patients with varying severity of PAD symptoms.

  20. Fundamental parameters of massive stars in multiple systems: The cases of HD 17505A and HD 206267A

    NASA Astrophysics Data System (ADS)

    Raucq, F.; Rauw, G.; Mahy, L.; Simón-Díaz, S.

    2018-06-01

    Context. Many massive stars are part of binary or higher multiplicity systems. The present work focusses on two higher multiplicity systems: HD 17505A and HD 206267A. Aims: Determining the fundamental parameters of the components of the inner binary of these systems is mandatory to quantify the impact of binary or triple interactions on their evolution. Methods: We analysed high-resolution optical spectra to determine new orbital solutions of the inner binary systems. After subtracting the spectrum of the tertiary component, a spectral disentangling code was applied to reconstruct the individual spectra of the primary and secondary. We then analysed these spectra with the non-LTE model atmosphere code CMFGEN to establish the stellar parameters and the CNO abundances of these stars. Results: The inner binaries of these systems have eccentric orbits with e 0.13 despite their relatively short orbital periods of 8.6 and 3.7 days for HD 17505Aa and HD 206267Aa, respectively. Slight modifications of the CNO abundances are found in both components of each system. The components of HD 17505Aa are both well inside their Roche lobe, whilst the primary of HD 206267Aa nearly fills its Roche lobe around periastron passage. Whilst the rotation of the primary of HD 206267Aa is in pseudo-synchronization with the orbital motion, the secondary displays a rotation rate that is higher. Conclusions: The CNO abundances and properties of HD 17505Aa can be explained by single star evolutionary models accounting for the effects of rotation, suggesting that this system has not yet experienced binary interaction. The properties of HD 206267Aa suggest that some intermittent binary interaction might have taken place during periastron passages, but is apparently not operating anymore. Based on observations collected with the TIGRE telescope (La Luz, Mexico), the 1.93 m telescope at Observatoire de Haute Provence (France), the Nordic Optical Telescope at the Observatorio del Roque de los Muchachos (La Palma, Spain), and the Canada-France-Hawaii telescope (Mauna Kea, Hawaii).

  1. Modifications to give HOPE/MDC 2.0 the capability to solve for or consider vent forces: Mission planning, mission analysis, and software formulation

    NASA Technical Reports Server (NTRS)

    Zyla, L. V.

    1979-01-01

    The modifications are described as necessary to give the Houston Operations Predictor/Estimator (HOPE) program the capability to solve for or consider vent forces for orbit determination. The model implemented in solving for vent forces is described along with the integrator problems encountered. A summary derivation of the mathematical principles applicable to solve/consider methodology is provided.

  2. General Model for Multicomponent Ablation Thermochemistry

    NASA Technical Reports Server (NTRS)

    Milos, Frank S.; Marschall, Jochen; Rasky, Daniel J. (Technical Monitor)

    1994-01-01

    A previous paper (AIAA 94-2042) presented equations and numerical procedures for modeling the thermochemical ablation and pyrolysis of thermal protection materials which contain multiple surface species. This work describes modifications and enhancements to the Multicomponent Ablation Thermochemistry (MAT) theory and code for application to the general case which includes surface area constraints, rate limited surface reactions, and non-thermochemical mass loss (failure). Detailed results and comparisons with data are presented for the Shuttle Orbiter reinforced carbon-carbon oxidation protection system which contains a mixture of sodium silicate (Na2SiO3), silica (SiO2), silicon carbide (SiC), and carbon (C).

  3. Theory of Enceladus and Dione. [on Saturn satellites orbital motion

    NASA Technical Reports Server (NTRS)

    Jefferys, W. H.; Ries, L. M.

    1975-01-01

    A new theory of the motion of Enceladus and Dione is under development. The theory is in literal form, with all constants and parameters appearing explicitly, and is being computed with the aid of the algebraic manipulation system TRIGMAN. The development of the disturbing function; the elimination of the short-period terms; and the resonant Hamiltonian and the constants of integration are discussed. An important feature is that the programs have been written in such a manner that, with only minor modification, they should be able to develop the theories of Mimas-Tethys and Titan-Hyperion as well.

  4. Space Shuttle Orbiter Approach and Landing Test: Final Evaluation Report

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The Approach and Landing Test Program consisted of a series of steps leading to the demonstration of the capability of the Space Shuttle orbiter to safely approach and land under conditions similar to those planned for the final phases of an orbital flight. The tests were conducted with the orbiter mounted on top of a specially modified carrier aircraft. The first step provided airworthiness and performance verification of the carrier aircraft after modification. The second step consisted of three taxi tests and five flight tests with an inert unmanned orbiter. The third step consisted of three mated tests with an active manned orbiter. The fourth step consisted of five flights in which the orbiter was separated from the carrier aircraft. For the final two flights, the orbiter tail cone was replaced by dummy engines to simulate the actual orbital configuration. Landing gear braking and steering tests were accomplished during rollouts following the free flight landings. Ferry testing was integrated into the Approach and Landing Test Program to the extent possible. In addition, four ferry test flights were conducted with the orbiter mated to the carrier aircraft in the ferry configuration after the free-flight tests were completed.

  5. Effects of solar radiation on the orbits of small particles

    NASA Technical Reports Server (NTRS)

    Lyttleton, R. A.

    1976-01-01

    A modification of the Robertson (1937) equations of particle motion in the presence of solar radiation is developed which allows for partial reflection of sunlight as a result of rapid and varying particle rotations caused by interaction with the solar wind. The coefficients and forces in earlier forms of the equations are compared with those in the present equations, and secular rates of change of particle orbital elements are determined. Orbital dimensions are calculated in terms of time, probable sizes and densities of meteoric and cometary particles are estimated, and times of infall to the sun are computed for a particle moving in an almost circular orbit and a particle moving in an elliptical orbit of high eccentricity. Changes in orbital elements are also determined for particles from a long-period sun-grazing comet. The results show that the time of infall to the sun from a highly eccentric orbit is substantially shorter than from a circular orbit with a radius equal to the mean distance in the eccentric orbit. The possibility is considered that the free orbital kinetic energy of particles drawn into the sun may be the energy source for the solar corona.

  6. Exact density functional and wave function embedding schemes based on orbital localization

    NASA Astrophysics Data System (ADS)

    Hégely, Bence; Nagy, Péter R.; Ferenczy, György G.; Kállay, Mihály

    2016-08-01

    Exact schemes for the embedding of density functional theory (DFT) and wave function theory (WFT) methods into lower-level DFT or WFT approaches are introduced utilizing orbital localization. First, a simple modification of the projector-based embedding scheme of Manby and co-workers [J. Chem. Phys. 140, 18A507 (2014)] is proposed. We also use localized orbitals to partition the system, but instead of augmenting the Fock operator with a somewhat arbitrary level-shift projector we solve the Huzinaga-equation, which strictly enforces the Pauli exclusion principle. Second, the embedding of WFT methods in local correlation approaches is studied. Since the latter methods split up the system into local domains, very simple embedding theories can be defined if the domains of the active subsystem and the environment are treated at a different level. The considered embedding schemes are benchmarked for reaction energies and compared to quantum mechanics (QM)/molecular mechanics (MM) and vacuum embedding. We conclude that for DFT-in-DFT embedding, the Huzinaga-equation-based scheme is more efficient than the other approaches, but QM/MM or even simple vacuum embedding is still competitive in particular cases. Concerning the embedding of wave function methods, the clear winner is the embedding of WFT into low-level local correlation approaches, and WFT-in-DFT embedding can only be more advantageous if a non-hybrid density functional is employed.

  7. Space Shuttle Exhaust Modifications of the Mid-Latitude Ionospheric Plasma As Diagnosed By Ground Based Radar

    NASA Astrophysics Data System (ADS)

    Lind, F. D.; Erickson, P. J.; Bhatt, A.; Bernhardt, P. A.

    2009-12-01

    The Space Shuttle's Orbital Maneuvering System (OMS) engines have been used since the early days of the STS program for active ionospheric modification experiments designed to be viewed by ground based ionospheric radar systems. In 1995, the Naval Research Laboratory initiated the Shuttle Ionospheric Modification with Pulsed Localized Exhaust (SIMPLEX) Program using dedicated Space Shuttle OMS burns scheduled through the US Department of Defense's Space Test Program. SIMPLEX objectives include generation of localized ion-acoustic turbulence and the formation of ionospheric density irregularities for injections perpendicular to the local magnetic field, creating structures which can scatter incident UHF radar signals. We discuss radar observations made during several recent SIMPLEX mid-latitude experiments conducted over the Millstone Hill incoherent scatter radar system in Westford, Massachusetts. OMS engine firings release 10 kg/s of CO2, H2, H2O, and N2 molecules which charge exchange with ambient O+ ions in the F region, producing molecular ions and long lived electron density depletions as recombination occurs with ambient electrons. Depending on the magnetic field angle, the high velocity of the injected reactive exhaust molecules relative to the background ionosphere can create longitudinal propagating ion acoustic waves with amplitudes well above normal thermal levels and stimulate a wide variety of plasma instability processes. These effects produce high radar cross section targets readily visible to the Millstone Hill system, a high power large aperture radar designed to measure very weak scatter from the quiescent background ionosphere. We will survey the plasma instability parameter space explored to date and discuss plans for future SIMPLEX observations.

  8. DET/MPS - THE GSFC ENERGY BALANCE PROGRAM, DIRECT ENERGY TRANSFER/MULTIMISSION SPACECRAFT MODULAR POWER SYSTEM (DEC VAX VMS VERSION)

    NASA Technical Reports Server (NTRS)

    Jagielski, J. M.

    1994-01-01

    The DET/MPS programs model and simulate the Direct Energy Transfer and Multimission Spacecraft Modular Power System in order to aid both in design and in analysis of orbital energy balance. Typically, the DET power system has the solar array directly to the spacecraft bus, and the central building block of MPS is the Standard Power Regulator Unit. DET/MPS allows a minute-by-minute simulation of the power system's performance as it responds to various orbital parameters, focusing its output on solar array output and battery characteristics. While this package is limited in terms of orbital mechanics, it is sufficient to calculate eclipse and solar array data for circular or non-circular orbits. DET/MPS can be adjusted to run one or sequential orbits up to about one week, simulated time. These programs have been used on a variety of Goddard Space Flight Center spacecraft projects. DET/MPS is written in FORTRAN 77 with some VAX-type extensions. Any FORTRAN 77 compiler that includes VAX extensions should be able to compile and run the program with little or no modifications. The compiler must at least support free-form (or tab-delineated) source format and 'do do-while end-do' control structures. DET/MPS is available for three platforms: GSC-13374, for DEC VAX series computers running VMS, is available in DEC VAX Backup format on a 9-track 1600 BPI tape (standard distribution) or TK50 tape cartridge; GSC-13443, for UNIX-based computers, is available on a .25 inch streaming magnetic tape cartridge in UNIX tar format; and GSC-13444, for Macintosh computers running AU/X with either the NKR FORTRAN or AbSoft MacFORTRAN II compilers, is available on a 3.5 inch 800K Macintosh format diskette. Source code and test data are supplied. The UNIX version of DET requires 90K of main memory for execution. DET/MPS was developed in 1990. A/UX and Macintosh are registered trademarks of Apple Computer, Inc. VMS, DEC VAX and TK50 are trademarks of Digital Equipment Corporation. UNIX is a registered trademark of AT&T Bell Laboratories.

  9. DET/MPS - THE GSFC ENERGY BALANCE PROGRAM, DIRECT ENERGY TRANSFER/MULTIMISSION SPACECRAFT MODULAR POWER SYSTEM (UNIX VERSION)

    NASA Technical Reports Server (NTRS)

    Jagielski, J. M.

    1994-01-01

    The DET/MPS programs model and simulate the Direct Energy Transfer and Multimission Spacecraft Modular Power System in order to aid both in design and in analysis of orbital energy balance. Typically, the DET power system has the solar array directly to the spacecraft bus, and the central building block of MPS is the Standard Power Regulator Unit. DET/MPS allows a minute-by-minute simulation of the power system's performance as it responds to various orbital parameters, focusing its output on solar array output and battery characteristics. While this package is limited in terms of orbital mechanics, it is sufficient to calculate eclipse and solar array data for circular or non-circular orbits. DET/MPS can be adjusted to run one or sequential orbits up to about one week, simulated time. These programs have been used on a variety of Goddard Space Flight Center spacecraft projects. DET/MPS is written in FORTRAN 77 with some VAX-type extensions. Any FORTRAN 77 compiler that includes VAX extensions should be able to compile and run the program with little or no modifications. The compiler must at least support free-form (or tab-delineated) source format and 'do do-while end-do' control structures. DET/MPS is available for three platforms: GSC-13374, for DEC VAX series computers running VMS, is available in DEC VAX Backup format on a 9-track 1600 BPI tape (standard distribution) or TK50 tape cartridge; GSC-13443, for UNIX-based computers, is available on a .25 inch streaming magnetic tape cartridge in UNIX tar format; and GSC-13444, for Macintosh computers running AU/X with either the NKR FORTRAN or AbSoft MacFORTRAN II compilers, is available on a 3.5 inch 800K Macintosh format diskette. Source code and test data are supplied. The UNIX version of DET requires 90K of main memory for execution. DET/MPS was developed in 1990. A/UX and Macintosh are registered trademarks of Apple Computer, Inc. VMS, DEC VAX and TK50 are trademarks of Digital Equipment Corporation. UNIX is a registered trademark of AT&T Bell Laboratories.

  10. DET/MPS - THE GSFC ENERGY BALANCE PROGRAM, DIRECT ENERGY TRANSFER/MULTIMISSION SPACECRAFT MODULAR POWER SYSTEM (MACINTOSH A/UX VERSION)

    NASA Technical Reports Server (NTRS)

    Jagielski, J. M.

    1994-01-01

    The DET/MPS programs model and simulate the Direct Energy Transfer and Multimission Spacecraft Modular Power System in order to aid both in design and in analysis of orbital energy balance. Typically, the DET power system has the solar array directly to the spacecraft bus, and the central building block of MPS is the Standard Power Regulator Unit. DET/MPS allows a minute-by-minute simulation of the power system's performance as it responds to various orbital parameters, focusing its output on solar array output and battery characteristics. While this package is limited in terms of orbital mechanics, it is sufficient to calculate eclipse and solar array data for circular or non-circular orbits. DET/MPS can be adjusted to run one or sequential orbits up to about one week, simulated time. These programs have been used on a variety of Goddard Space Flight Center spacecraft projects. DET/MPS is written in FORTRAN 77 with some VAX-type extensions. Any FORTRAN 77 compiler that includes VAX extensions should be able to compile and run the program with little or no modifications. The compiler must at least support free-form (or tab-delineated) source format and 'do do-while end-do' control structures. DET/MPS is available for three platforms: GSC-13374, for DEC VAX series computers running VMS, is available in DEC VAX Backup format on a 9-track 1600 BPI tape (standard distribution) or TK50 tape cartridge; GSC-13443, for UNIX-based computers, is available on a .25 inch streaming magnetic tape cartridge in UNIX tar format; and GSC-13444, for Macintosh computers running AU/X with either the NKR FORTRAN or AbSoft MacFORTRAN II compilers, is available on a 3.5 inch 800K Macintosh format diskette. Source code and test data are supplied. The UNIX version of DET requires 90K of main memory for execution. DET/MPS was developed in 1990. A/UX and Macintosh are registered trademarks of Apple Computer, Inc. VMS, DEC VAX and TK50 are trademarks of Digital Equipment Corporation. UNIX is a registered trademark of AT&T Bell Laboratories.

  11. The Complex History of Trojan Asteroids

    NASA Astrophysics Data System (ADS)

    Emery, J. P.; Marzari, F.; Morbidelli, A.; French, L. M.; Grav, T.

    The Trojan asteroids, orbiting the Sun in Jupiter's stable Lagrange points, provide a unique perspective on the history of our solar system. As a large population of small bodies, they record important gravitational interactions in the dynamical evolution of the solar system. As primitive bodies, their compositions and physical properties provide windows into the conditions in the solar nebula in the region in which they formed. In the past decade, significant advances have been made in understanding their physical properties, and there has been a revolution in thinking about the origin of Trojans. The ice and organics generally presumed to be a significant part of Trojan composition have yet to be detected directly, although the low density of the binary system Patroclus (and possibly low density of the binary/moonlet system Hektor) is consistent with an interior ice component. By contrast, fine-grained silicates that appear to be similar to cometary silicates in composition have been detected, and a color bimodality may indicate distinct compositional groups among the Trojans. Whereas Trojans had traditionally been thought to have formed near 5 AU, a new paradigm has developed in which the Trojans formed in the proto-Kuiper belt, and were scattered inward and captured in the Trojan swarms as a result of resonant interactions of the giant planets. Whereas the orbital and population distributions of current Trojans are consistent with this origin scenario, there are significant differences between current physical properties of Trojans and those of Kuiper belt objects. These differences may be indicative of surface modification due to the inward migration of objects that became the Trojans, but understanding of appropriate modification mechanisms is poor and would benefit from additional laboratory studies. Many open questions about this intriguing population remain, and the future promises significant strides in our understanding of Trojans. The time is ripe for a spacecraft mission to the Trojans, to transform these objects into geologic worlds that can be studied in detail to unravel their complex history.

  12. ESA and NASA agree new mission scenario for Cassini-Huygens

    NASA Astrophysics Data System (ADS)

    2001-07-01

    After six months of investigations and analysis by a joint ESA/NASA Huygens Recovery Task Force (HRTF), senior management from the two space agencies and members of the Cassini-Huygens scientific community have endorsed several modifications to the mission. These will ensure a return close to 100% of the Huygens science data, with no impact on the nominal prime Cassini tour after the third Titan encounter. The modifications have been introduced because of a design flaw in the Huygens communication system. This problem meant that the Huygens receiver was unable to compensate for the frequency shift between the signal emitted by the Probe and the one received by the Orbiter, due to the Doppler shift (**). This would have resulted in the loss of most of the unique data returned from the Probe during its descent through Titan’s dense atmosphere. To ensure that as much data as possible is returned from the pioneering Probe, the HRTF proposed a new schedule for Cassini’s first orbits around Saturn. The agreed scenario involves shortening Cassini’s first two orbits around the ringed planet and adding a third which provides the required new geometry for the Huygens mission to Titan. In the new scenario, the arrival at Saturn on 1 July 2004 remains unchanged. However, Cassini’s first flyby of Titan will now occur on 26 October, followed by another on 13 December. The Huygens Probe will be released towards Titan on 25 December, for an entry into the moon’s atmosphere 22 days later, on 14 January 2005, seven weeks later than originally planned. To reduce the Doppler shift in the signal from Huygens, the Cassini Orbiter will fly over Titan’s cloud tops at a much higher altitude than originally planned - 65,000 km instead of 1,200 km. This higher orbit has the added advantage that Cassini will be able to preserve the four-year baseline tour through the Saturn system, by resuming its original orbital plan in mid-February 2005. “In any complex space mission problems may arise,” said John Credland, Head of ESA’s Space Science Projects Department. “The measure of an organisation is the manner in which it recovers.” The new mission scenario will have some impact on Cassini’s propellant supply, consuming about a quarter of the Orbiter’s reserve fuel by the end of the four-year mission. It also involves several modifications to ensure maximum efficiency of the Huygens communications system. These include pre-heating the Probe to improve tuning of the transmitted signal, continuous commanding by the Orbiter to force the receiver into non-Doppler mode, and changes in the Probe’s on-board software. "I am very happy that we have found a good engineering solution,” said Kai Clausen, ESA’s Integral Project Manager and co-chairman of the HRTF. “But a lot more work still needs to be done. Now we need to complete the detailed design, implementation, validation and testing over the next few years." “There are still some uncertainties, for example the exact definition of the landing site, but these are minor problems,” said Jean-Pierre Lebreton, ESA’s Huygens Project Scientist. “What is important is that we have found the solution. It is now time for fine tuning.” The ESA Director of Science, David Southwood, and the NASA Associate Director for Space Science, Edward Weiler, have jointly agreed to the new mission approach and have asked the HRTF to hand over to the project teams in July for implementation of the joint recommendations. (**) The Doppler shift is a measure of the difference in tone between an emitted and a received wave (e.g. radio) when the transmitting source and the receiver move one with respect to the other. Note to editors Cassini-Huygens is a joint NASA/ESA mission with the participation of the Italian Space Agency (ASI) launched by a Titan IVB/Centaur launch vehicle on 15 October 1997, that will reach Saturn in 2004. It consists of NASA's orbiter Cassini and ESA's probe Huygens. While Cassini continues to explore Saturn and its rings, the Huygens probe will be released to parachute through the atmosphere of Titan. Shrouded in an orange haze that hides its surface, Titan is one of the most mysterious objects in our Solar System. It is the second largest moon (only Jupiter’s Ganymede is bigger), and the only one with a thick atmosphere. It is this atmosphere that excites scientific interest, since it is thought to resemble that of a very young Earth.

  13. Lunar Cube Transfer Trajectory Options

    NASA Technical Reports Server (NTRS)

    Folta, David C.; Dichman, Don; Clark, Pamela; Haapala, Amanda; Howell, Kathleen

    2014-01-01

    Contingent upon the modification of an initial condition of the injected or deployed orbit. Additionally, these designs can be restricted by the selection of the Cubesat subsystem design such as propulsion or communication. Nonetheless, many trajectory options can be designed with have a wide range of transfer durations, fuel requirements, and final destinations. Our investigation of potential trajectories highlights several design options including deployment into low Earth orbit (LEO), geostationary transfer orbits (GTO), and higher energy direct lunar transfer orbits. In addition to direct transfer options from these initial orbits, we also investigate the use of longer duration Earth-Moon dynamical systems. For missions with an intended lunar orbit, much of the design process is spent optimizing a ballistic capture while other science locations such as Sun-Earth libration or heliocentric orbits may simply require a reduced Delta-V imparted at a convenient location along the trajectory. In this article we examine several design options that meet the above limited deployment and subsystem drivers. We study ways that both impulsive and low-thrust Solar Electric Propulsion (SEP) engines can be used to place the Cubesat first into a highly eccentric Earth orbit, enter the Moon's Sphere of Influence, and finally achieve a highly eccentric lunar orbit. We show that such low-thrust transfers are feasible with a realistic micro-thruster model, assuming that the Cubesat can generate sufficient power for the SEP. Two examples are shown here: (1) A Cubestat injected by Exploration Mission 1 (EM-1) then employing low thrust; and (2) a CubSat deployed in a GTO, then employing impulsive maneuvers. For the EM-1 injected initial design, we increase the EM-1 targeted lunar flyby distance to reduce the energy of the lunar flyby to match that of a typical lMoon system heteroclinic manifold. Figure 1 presents an option that encompasses the similar dynamics as that of the ARTEMIS mission design. Low-thrust maneuvers are used along the manifold trajectory to raise perigee to that of a lunar orbit, adjust the timing with respect to the Moon, rotate the line of apsides, and target a ballistic lunar encounter. In this design a second flyby decreases the orbital energy with respect to the Moon, so that C3 -0.1 km2s2. Another design, shown in Figure 2 emanates from a GTO then uses impulsive maneuvers to phase onto a local Earth-Moon manifold, which then transfers the CubeSat to a lunar encounter.

  14. Transfer and capture into distant retrograde orbits

    NASA Astrophysics Data System (ADS)

    Scott, Christopher J.

    This dissertation utilizes theory and techniques derived from the fields of dynamical systems theory, astrodyanamics, celestial mechanics, and fluid mechanics to analyze the phenomenon of satellite capture and interrelated spacecraft transfers in restricted three-body systems. The results extend current knowledge and understanding of capture dynamics in the context of astrodynamics and celestial mechanics. Manifold theory, fast Lyapunov indicator maps, and the classification of space structure facilitate an analysis of the transport of objects from the chaotic reaches of the solar system to the distant retrograde region in the sun-Jupiter system. Apart from past studies this dissertation considers the role of the complex lobe structure encompassing stable regions in the circular restricted three-body problem. These structures are shown to be responsible for the phenomenon of sticky orbits and the transport of objects among stable regions. Since permanent capture can only be achieved through a change in energy, fast Lyapunov indicator maps and other methods which reveal the structure of the conservative system are used to discern capture regions and identify the underpinnings of the dynamics. Fast Lyapunov indicator maps provide an accurate classification of orbits of permanent capture and escape, yet monopolize computational resources. In anticipation of a fully three-dimensional analysis in the dissipative system a new mapping parameter is introduced based on energy degradation and averaged velocity. Although the study specifically addresses the sun-Jupiter system, the qualitative results and devised techniques can be applied throughout the solar system and to capture about extrasolar planets. Extending the analysis beyond the exterior of the stable distant retrograde region fosters the construction of transfer orbits from low-Earth orbit to a stable periodic orbit at the center of the stable distant retrograde region. Key to this analysis is the predictability of collision orbits within the highly chaotic region commonly recognized as a saddle point on the energy manifold. The pragmatic techniques derived from this analysis solve a number of complications apparent in the literature. Notably a reliable methodology for the construction of an arbitrary number of transfer orbits circumvents the requirement of computing specialized periodic orbits or extensive numerical sampling of the phase space. The procedure provides a complete description of the design space accessing a wide range of distant retrograde orbits sizes, insertion points, and parking orbit altitudes in an automated manner. The transfers are studied in a similar fashion to periodic orbits unveiling the intimate relationship among design parameters and phase space structure. An arbitrary number of Earth return periodic orbits can be generated as a by-product. These orbits may be useful for spacecraft that must make a number of passes near the second primary without a reduction in energy. Further analysis of the lobe dynamics and a modification of the transfers to the center of the stable region yields sets of single impulse transfers to sticky distant retrograde orbits. It is shown that the evolution of the phase space structures with energy corresponds to the variation of capture time and target size. Capture phenomenon is related to the stability characteristics of the unstable periodic orbit and the geometry of the corresponding homoclinic tangle at various energies. Future spacecraft with little or no propulsive means may take advantage of these natural trajectories for operations in the region. Temporary capture along a sticky orbit may come before incremental stabilization of the spacecraft by way of a series of small impulsive or a low continuous thrust maneuvers. The requirements of small stabilization maneuver are calculated and compared to a direct transfer to the center of stable region. This mission design may be desirable as any failure in the classic set of maneuvers to the center of the stable region could result in the loss of the spacecraft. A simple low-thrust stabilization method is analyzed in a similar manner to nebular drag. It is shown that stabilization maneuvers initiated within the sticky region can be achieved via a simple control law. Moreover, the sticky region can be used as a staging point for both spiral-in and spiral-out maneuvers. For the spiral in maneuver this negates a large, initial maneuver required to reach the center of the stable region. It is shown that large lengths of orbits exist within the sticky regions which reliably lead to permanent capture. In the case of spiral-out the spacecraft is transported to a highly energetic yet stable orbit about the second primary. From here a small maneuver could allow the spacecraft to access other regions of the solar system.

  15. Investigation for improving Global Positioning System (GPS) orbits using a discrete sequential estimator and stochastic models of selected physical processes

    NASA Technical Reports Server (NTRS)

    Goad, Clyde C.; Chadwell, C. David

    1993-01-01

    GEODYNII is a conventional batch least-squares differential corrector computer program with deterministic models of the physical environment. Conventional algorithms were used to process differenced phase and pseudorange data to determine eight-day Global Positioning system (GPS) orbits with several meter accuracy. However, random physical processes drive the errors whose magnitudes prevent improving the GPS orbit accuracy. To improve the orbit accuracy, these random processes should be modeled stochastically. The conventional batch least-squares algorithm cannot accommodate stochastic models, only a stochastic estimation algorithm is suitable, such as a sequential filter/smoother. Also, GEODYNII cannot currently model the correlation among data values. Differenced pseudorange, and especially differenced phase, are precise data types that can be used to improve the GPS orbit precision. To overcome these limitations and improve the accuracy of GPS orbits computed using GEODYNII, we proposed to develop a sequential stochastic filter/smoother processor by using GEODYNII as a type of trajectory preprocessor. Our proposed processor is now completed. It contains a correlated double difference range processing capability, first order Gauss Markov models for the solar radiation pressure scale coefficient and y-bias acceleration, and a random walk model for the tropospheric refraction correction. The development approach was to interface the standard GEODYNII output files (measurement partials and variationals) with software modules containing the stochastic estimator, the stochastic models, and a double differenced phase range processing routine. Thus, no modifications to the original GEODYNII software were required. A schematic of the development is shown. The observational data are edited in the preprocessor and the data are passed to GEODYNII as one of its standard data types. A reference orbit is determined using GEODYNII as a batch least-squares processor and the GEODYNII measurement partial (FTN90) and variational (FTN80, V-matrix) files are generated. These two files along with a control statement file and a satellite identification and mass file are passed to the filter/smoother to estimate time-varying parameter states at each epoch, improved satellite initial elements, and improved estimates of constant parameters.

  16. RHIC BPM SYSTEM MODIFICATIONS AND PERFORMANCE.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    SATOGATA, T.; CALAGA, R.; CAMERON, P.

    2005-05-16

    The RHIC beam position monitor (BPM) system provides independent average orbit and turn-by-turn (TBT) position measurements. In each ring, there are 162 measurement locations per plane (horizontal and vertical) for a total of 648 BPM planes in the RHIC machine. During 2003 and 2004 shutdowns, BPM processing electronics were moved from the RHIC tunnel to controls alcoves to reduce radiation impact, and the analog signal paths of several dozen modules were modified to eliminate gain-switching relays and improve signal stability. This paper presents results of improved system performance, including stability for interaction region beam-based alignment efforts. We also summarize performancemore » of recently-added DSP profile scan capability, and improved million-turn TBT acquisition channels for 10 Hz triplet vibration, nonlinear dynamics, and echo studies.« less

  17. Mitigating Climate Change with Earth Orbital Sunshades

    NASA Technical Reports Server (NTRS)

    Coverstone, Victoria; Johnson, Les

    2015-01-01

    An array of rotating sunshades based on emerging solar sail technology will be deployed in a novel Earth orbit to provide near-continuous partial shading of the Earth, reducing the heat input to the atmosphere by blocking a small percentage of the incoming sunlight, and mitigating local weather effects of anticipated climate change over the next century. The technology will provide local cooling relief during extreme heat events (and heating relief during extreme cold events) thereby saving human lives, agriculture, livestock, water and energy needs. A synthesis of the solar sail design, the sails' operational modes, and the selected orbit combine to provide local weather modification.

  18. KSC-97PC1667

    NASA Image and Video Library

    1997-11-11

    KENNEDY SPACE CENTER, FLA. -- The orbiter Atlantis, riding atop the modified Boeing 747 Shuttle Carrier Aircraft, departed Kennedy Space Center (KSC) at 1:53 p.m. on Nov. 11 en route to Palmdale, Calif., for the planned Orbiter Maintenance Down Period. Atlantis departed from KSC’s Shuttle Landing Facility Runway 33 for Palmdale’s Orbiter Assembly Facility, where it will remain until August 1998. At Palmdale, modifications and structural inspections will be conducted in preparation for Atlantis’ future missions to support International Space Station assembly activities. Atlantis’ next flight into space is scheduled to be Space Shuttle mission STS-92, targeted for launch from KSC in January 1999

  19. Proposed Facility Modifications to Support Propulsion Systems Testing Under Simulated Space Conditions at Plum Brook Station's Spacecraft Propulsion Research Facility (B-2)

    NASA Technical Reports Server (NTRS)

    Edwards, Daryl A.

    2007-01-01

    Preparing NASA's Plum Brook Station's Spacecraft Propulsion Research Facility (B-2) to support NASA's new generation of launch vehicles has raised many challenges for B-2 s support staff. The facility provides a unique capability to test chemical propulsion systems/vehicles while simulating space thermal and vacuum environments. Designed and constructed 4 decades ago to support upper stage cryogenic engine/vehicle system development, the Plum Brook Station B-2 facility will require modifications to support the larger, more powerful, and more advanced engine systems for the next generation of vehicles leaving earth's orbit. Engine design improvements over the years have included large area expansion ratio nozzles, greater combustion chamber pressures, and advanced materials. Consequently, it has become necessary to determine what facility changes are required and how the facility can be adapted to support varying customers and their specific test needs. Instrumental in this task is understanding the present facility capabilities and identifying what reasonable changes can be implemented. A variety of approaches and analytical tools are being employed to gain this understanding. This paper discusses some of the challenges in applying these tools to this project and expected facility configuration to support the varying customer needs.

  20. Skylab

    NASA Image and Video Library

    1967-09-01

    This September 1967 photograph shows workmen removing a mockup of the Saturn V S-IVB stage that housed the Skylab Orbital Workshop (OWS) from the Marshall Space Flight Center (MSFC), building 4755. The mockup was shipped to McDornell Douglas in Huntington, California for design modifications. NASA used the mockup as an engineering design tool to plan structures, equipment, and experiments for Skylab, an orbiting space laboratory. The MSFC had program management responsibility for the development of Skylab hardware and experiments, including the OWS.

  1. Gemini Program Mission Report for Gemini-Titan 1 (GT-1)

    NASA Technical Reports Server (NTRS)

    1964-01-01

    The Gemini-Titan 1 (GT-1) space vehicle was comprised of the Gemini spacecraft and the Gemini launch vehicle. The Gemini launch vehicle is a two-stage modified Titan II ICBM. The major modifications are the addition of a malfunction detection system and a secondary flight controls system. The Gemini spacecraft, designed to carry a crew of two men on earth orbital and rendezvous missions, was unmanned for the flight reported herein (GT-1). There were no complete Gemini flight systems on board; however, the C-band transponder and telemetry transmitters were Gemini flight subsystems. Dummy equipment, having a mass and moment of inertia equal to flight system equipment, was installed in the spacecraft. The Spacecraft was instrumented to obtain data on spacecraft heating, structural loading, vibration, sound pressure levels, and temperature and pressure during the launch phase.

  2. STS mission duration enhancement study: (orbiter habitability)

    NASA Technical Reports Server (NTRS)

    Carlson, A. D.

    1979-01-01

    Habitability improvements for early flights that could be implemented with minimum impact were investigated. These included: (1) launching the water dispenser in the on-orbit position instead of in a locker; (2) the sleep pallet concept; and (3) suction cup foot restraints. Past studies that used volumetric terms and requirements for crew size versus mission duration were reviewed and common definitions of key habitability terms were established. An accurately dimensioned drawing of the orbiter mid-deck, locating all of the known major elements was developed. Finally, it was established that orbiter duration and crew size can be increased with minimum modification and impact to the crew module. Preliminary concepts of the aft med-deck, external versions of expanded tunnel adapters (ETA), and interior concepts of ETA-3 were developed and comparison charts showing the various factors of volume, weight, duration, size, impact to orbiter, and number of sleep stations were generated.

  3. STS-26: The return to flight

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The major activities leading up to the return to flight of the Space Shuttles are summarized. Major orbiter modifications and solid rocket motor redesign are described. Shuttle payloads are discussed briefly. Also provided are the biographies of the crew.

  4. ISTP SBIR phase 1 Full-Sky Scanner: A feasibility study

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The objective was to develop a Full-Sky Sensor (FSS) to detect the Earth, Sun and Moon from a spinning spacecraft. The concept adopted has infinitely variable resolution. A high-speed search mode is implemented on the spacecraft. The advantages are: (1) a single sensor determines attitude parameters from Earth, Sun and Moon, thus eliminating instrument mounting errors; (2) the bias between the actual spacecraft spin axis and the intended spin axis can be determined; (3) cost is minimized; and (4) ground processing is straightforward. The FSS is a modification of an existing flight-proven sensor. Modifications to the electronics are necessary to accommodate the amplitude range and signal width range of the celestial bodies to be detected. Potential applications include ISTP missions, Multi-Spacecraft Satellite Program (MSSP), dual-spin spacecraft at any altitude, spinning spacecraft at any altitude, and orbit parameter determination for low-Earth orbits.

  5. ISTP SBIR phase 1 Full-Sky Scanner: A feasibility study

    NASA Astrophysics Data System (ADS)

    1986-08-01

    The objective was to develop a Full-Sky Sensor (FSS) to detect the Earth, Sun and Moon from a spinning spacecraft. The concept adopted has infinitely variable resolution. A high-speed search mode is implemented on the spacecraft. The advantages are: (1) a single sensor determines attitude parameters from Earth, Sun and Moon, thus eliminating instrument mounting errors; (2) the bias between the actual spacecraft spin axis and the intended spin axis can be determined; (3) cost is minimized; and (4) ground processing is straightforward. The FSS is a modification of an existing flight-proven sensor. Modifications to the electronics are necessary to accommodate the amplitude range and signal width range of the celestial bodies to be detected. Potential applications include ISTP missions, Multi-Spacecraft Satellite Program (MSSP), dual-spin spacecraft at any altitude, spinning spacecraft at any altitude, and orbit parameter determination for low-Earth orbits.

  6. Aeroassisted manned transfer vehicle (TAXI) for advanced Mars Transportation: NASA/USRA 1987 Senior Design Project

    NASA Technical Reports Server (NTRS)

    1987-01-01

    A conceptual design study of an aeroassisted orbital transfer vehicle is discussed. Nicknamed TAXI, it will ferry personnel and cargo: (1) between low Earth orbit and a spacecraft circling around the Sun in permanent orbit intersecting gravitational fields of Earth and Mars, and (2) between the cycling spacecraft and a Mars orbiting station, co-orbiting with Phobos. Crew safety and mission flexibility (in terms of ability to provide a wide range of delta-V) were given high priority. Three versions were considered, using the same overall configuration based on a low L/D aerobrake with the geometry of a raked off elliptical cone with ellipsoidal nose and a toroidal skirt. The propulsion system consists of three gimballed LOX/LH2 engines firing away from the aerobrake. The versions differ mainly in the size of the aeroshields and propellant tanks. TAXI A version resulted from an initial effort to design a single transfer vehicle able to meet all delta-V requirements during the 15-year period (2025 to 2040) of Mars mission operations. TAXI B is designed to function with the cycling spacecraft moving in a simplified, nominal trajectory. On Mars missions, TAXI B would be able to meet the requirements of all the missions with a relative approach velocity near Mars of less than 9.3 km/sec. Finally, TAXI C is a revision of TAXI A, a transfer vehicle designed for missions with a relative velocity near Mars larger than 9.3 km/sec. All versions carry a crew of 9 (11 with modifications) and a cargo of 10000 lbm. Trip duration varies from 1 day for transfer from LEO to the cycling ship to nearly 5 days for transfer from the ship to the Phobos orbit.

  7. Protoflight photovoltaic power module system-level tests in the space power facility

    NASA Technical Reports Server (NTRS)

    Rivera, Juan C.; Kirch, Luke A.

    1989-01-01

    Work Package Four, which includes the NASA-Lewis and Rocketdyne, has selected an approach for the Space Station Freedom Photovoltaic (PV) Power Module flight certification that combines system level qualification and acceptance testing in the thermal vacuum environment: The protoflight vehicle approach. This approach maximizes ground test verification to assure system level performance and to minimize risk of on-orbit failures. The preliminary plans for system level thermal vacuum environmental testing of the protoflight PV Power Module in the NASA-Lewis Space Power Facility (SPF), are addressed. Details of the facility modifications to refurbish SPF, after 13 years of downtime, are briefly discussed. The results of an evaluation of the effectiveness of system level environmental testing in screening out incipient part and workmanship defects and unique failure modes are discussed. Preliminary test objectives, test hardware configurations, test support equipment, and operations are presented.

  8. A fully-neoclassical finite-orbit-width version of the CQL3D Fokker–Planck code

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Petrov, Yu V.; Harvey, R. W.

    The time-dependent bounce-averaged CQL3D flux-conservative finite-difference Fokker–Planck equation (FPE) solver has been upgraded to include finite-orbit-width (FOW) capabilities which are necessary for an accurate description of neoclassical transport, losses to the walls, and transfer of particles, momentum, and heat to the scrape-off layer. The FOW modifications are implemented in the formulation of the neutral beam source, collision operator, RF quasilinear diffusion operator, and in synthetic particle diagnostics. The collisional neoclassical radial transport appears naturally in the FOW version due to the orbit-averaging of local collision coefficients coupled with transformation coefficients from local (R, Z) coordinates along each guiding-center orbit tomore » the corresponding midplane computational coordinates, where the FPE is solved. In a similar way, the local quasilinear RF diffusion terms give rise to additional radial transport of orbits. We note that the neoclassical results are obtained for ‘full’ orbits, not dependent on a common small orbit-width approximation. Results of validation tests for the FOW version are also presented.« less

  9. A fully-neoclassical finite-orbit-width version of the CQL3D Fokker–Planck code

    DOE PAGES

    Petrov, Yu V.; Harvey, R. W.

    2016-09-08

    The time-dependent bounce-averaged CQL3D flux-conservative finite-difference Fokker–Planck equation (FPE) solver has been upgraded to include finite-orbit-width (FOW) capabilities which are necessary for an accurate description of neoclassical transport, losses to the walls, and transfer of particles, momentum, and heat to the scrape-off layer. The FOW modifications are implemented in the formulation of the neutral beam source, collision operator, RF quasilinear diffusion operator, and in synthetic particle diagnostics. The collisional neoclassical radial transport appears naturally in the FOW version due to the orbit-averaging of local collision coefficients coupled with transformation coefficients from local (R, Z) coordinates along each guiding-center orbit tomore » the corresponding midplane computational coordinates, where the FPE is solved. In a similar way, the local quasilinear RF diffusion terms give rise to additional radial transport of orbits. We note that the neoclassical results are obtained for ‘full’ orbits, not dependent on a common small orbit-width approximation. Results of validation tests for the FOW version are also presented.« less

  10. Ground controlled robotic assembly operations for Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Parrish, Joseph C.

    1991-01-01

    A number of dextrous robotic systems and associated positioning and transportation devices are available on Space Station Freedom (SSF) to perform assembly tasks that would otherwise need to be performed by extravehicular activity (EVA) crewmembers. The currently planned operating mode for these robotic systems during the assembly phase is teleoperation by intravehicular activity (IVA) crewmembers. While this operating mode is less hazardous and expensive than manned EVA operations, and has insignificant control loop time delays, the amount of IVA time available to support telerobotic operations is much less than the anticipated requirements. Some alternative is needed to allow the robotic systems to perform useful tasks without exhausting the available IVA resources; ground control is one such alternative. The issues associated with ground control of SSF robotic systems to alleviate onboard crew time availability constraints are investigated. Key technical issues include the effect of communication time delays, the need for safe, reliable execution of remote operations, and required modifications to the SSF ground and flight system architecture. Time delay compensation techniques such as predictive displays and world model-based force reflection are addressed and collision detection and avoidance strategies to ensure the safety of the on-orbit crew, Orbiter, and SSF are described. Although more time consuming and difficult than IVA controlled teleoperations or manned EVA, ground controlled telerobotic operations offer significant benefits during the SSF assembly phase, and should be considered in assembly planning activities.

  11. Space shuttle orbiter leading-edge flight performance compared to design goals

    NASA Technical Reports Server (NTRS)

    Curry, D. M.; Johnson, D. W.; Kelly, R. E.

    1983-01-01

    Thermo-structural performance of the Space Shuttle orbiter Columbia's leading-edge structural subsystem for the first five (5) flights is compared with the design goals. Lessons learned from thse initial flights of the first reusable manned spacecraft are discussed in order to assess design maturity, deficiencies, and modifications required to rectify the design deficiencies. Flight data and post-flight inspections support the conclusion that the leading-edge structural subsystem hardware performance was outstanding for the initial five (5) flights.

  12. The investigation of man-made modifications of the ionosphere. [effects of detonations and rocket exhaust

    NASA Technical Reports Server (NTRS)

    Bernhardt, P. A.; Darosa, A. V.; Price, K. M.

    1980-01-01

    Topics covered include: (1) the application of ionosphere modifications models to the simulation of results obtained when rocket-borne explosives were detonated in the ionosphere; (2) the problem of hypersonic vapor releases from orbiting vehicles; (3) measuring the electron content reduction resulting from the firing of a Centaur rocket in the ionosphere; and (4) the preliminary design of the critical frequency tracker which displays the value of electron concentration at the peak of the F 2 region, in real time.

  13. ASPOD modifications of 1993-1994

    NASA Technical Reports Server (NTRS)

    Jackson, Jennifer J. (Editor); Fogarty, Paul W.; Muller, Matthew; Martucci, Thomas A., III; Williams, Daniel; Rowney, David A.

    1994-01-01

    ASPOD, Autonomous Space Processors for Orbital Debris, provides a unique way of collecting the space debris that has built up over the past 37 years. For the past several years, ASPOD has gone through several different modifications. This year's concentrations were on the solar cutting array, the solar tracker, the earth based main frame/tilt table, the controls for the two robotic arms, and accurate autocad drawings of ASPOD. This final report contains the reports written by the students who worked on the ASPOD project this year.

  14. Direct characterization of photoinduced lattice dynamics in BaFe 2As 2

    DOE PAGES

    Gerber, S.; Kim, K. W.; Zhang, Y.; ...

    2015-06-08

    Ultrafast light pulses can modify electronic properties of quantum materials by perturbing the underlying, intertwined degrees of freedom. In particular, iron-based superconductors exhibit a strong coupling among electronic nematic fluctuations, spins and the lattice, serving as a playground for ultrafast manipulation. Here we use time-resolved X-ray scattering to measure the lattice dynamics of photoexcited BaFe 2As 2. On optical excitation, no signature of an ultrafast change of the crystal symmetry is observed, but the lattice oscillates rapidly in time due to the coherent excitation of an A1g mode that modulates the Fe–As–Fe bond angle. We directly quantify the coherent latticemore » dynamics and show that even a small photoinduced lattice distortion can induce notable changes in the electronic and magnetic properties. Our analysis implies that transient structural modification can be an effective tool for manipulating the electronic properties of multi-orbital systems, where electronic instabilities are sensitive to the orbital character of bands.« less

  15. Direct characterization of photoinduced lattice dynamics in BaFe2As2

    PubMed Central

    Gerber, S.; Kim, K. W.; Zhang, Y.; Zhu, D.; Plonka, N.; Yi, M.; Dakovski, G. L.; Leuenberger, D.; Kirchmann, P.S.; Moore, R. G.; Chollet, M.; Glownia, J. M.; Feng, Y.; Lee, J.-S.; Mehta, A.; Kemper, A. F.; Wolf, T.; Chuang, Y.-D.; Hussain, Z.; Kao, C.-C.; Moritz, B.; Shen, Z.-X.; Devereaux, T. P.; Lee, W.-S.

    2015-01-01

    Ultrafast light pulses can modify electronic properties of quantum materials by perturbing the underlying, intertwined degrees of freedom. In particular, iron-based superconductors exhibit a strong coupling among electronic nematic fluctuations, spins and the lattice, serving as a playground for ultrafast manipulation. Here we use time-resolved X-ray scattering to measure the lattice dynamics of photoexcited BaFe2As2. On optical excitation, no signature of an ultrafast change of the crystal symmetry is observed, but the lattice oscillates rapidly in time due to the coherent excitation of an A1g mode that modulates the Fe–As–Fe bond angle. We directly quantify the coherent lattice dynamics and show that even a small photoinduced lattice distortion can induce notable changes in the electronic and magnetic properties. Our analysis implies that transient structural modification can be an effective tool for manipulating the electronic properties of multi-orbital systems, where electronic instabilities are sensitive to the orbital character of bands. PMID:26051704

  16. Space environment effects on polymers in low earth orbit

    NASA Astrophysics Data System (ADS)

    Grossman, E.; Gouzman, I.

    2003-08-01

    Polymers are widely used in space vehicles and systems as structural materials, thermal blankets, thermal control coatings, conformal coatings, adhesives, lubricants, etc. The low earth orbit (LEO) space environment includes hazards such as atomic oxygen, UV radiation, ionizing radiation (electrons, protons), high vacuum, plasma, micrometeoroids and debris, as well as severe temperature cycles. Exposure of polymers and composites to the space environment may result in different detrimental effects via modification of their chemical, electrical, thermal, optical and mechanical properties as well as surface erosion. The high vacuum induces material outgassing (e.g. low-molecular weight residues, plasticizers and additives) and consequent contamination of nearby surfaces. The present work reviews the LEO space environment constituents and their interactions with polymers. Examples of degradation of materials exposed in ground simulation facilities are presented. The issues discussed include the erosion mechanisms of polymers, formation of contaminants and their interaction with the space environment, and protection of materials from the harsh space environment.

  17. The magnetospheric lobe at geosynchronous orbit

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Thomsen, M.F.; Bame, S.J.; McComas, D.J.

    1994-09-01

    On rare occasions, satellites at geosynchronous altitude enter the magnetospheric lobe, characterized by extremely low ion fluxes between 1 eV and 40 keV and electron fluxes above a few hundred eV. One year of plasma observations from two simultaneously operating spacecraft at synchronous orbit is surveyed for lobe encounters. A total of 34 full encounters and 56 apparent near encounters are identified, corresponding to {approximately}0.06% of the total observation time. Unlike energetic particle (E>40 keV) dropouts studied earlier, there is a strong tendency for the lobe encounters to occur postmidnight, as late as 07 local time. The two spacecraft encountermore » the lobe with different rates and in different seasons. These occurrence properties are not simply explicable in terms of the orbital geometry in either the solar magnetic or the geocentric solar magnetospheric coordinate system. A composite coordinate system which previously organized more energetic particle dropouts is somewhat more successful in organizing the lobe encounters, suggesting that solar wind distortion of the magnetic equatorial plane away from the dipole location and toward the antisolar direction may be largely responsible for these dropouts. The authors results further suggest that this distortion persists even sunward of the dawn-dusk terminator. However, a simple dawn-dusk symmetric distortion does not fully account for all the seasonal and local time asymmetries in the occurrence of the lobe encounters; thus there is probably an additional dawn-dusk asymmetry in the distorted field. The lobe encounters are strongly associated with magnetospheric activity and tend to occur in association with rare magnetosheath encounters at synchronous orbit. It thus appears that the presence of the lobe at geosynchronous orbit is the result of major, probably asymmetric modifications of the magnetospheric field geometry in times of strong disturbance. 19 refs., 7 figs., 1 tab.« less

  18. Asymmetric molecular-orbital tomography by manipulating electron trajectories

    NASA Astrophysics Data System (ADS)

    Wang, Bincheng; Zhang, Qingbin; Zhu, Xiaosong; Lan, Pengfei; Rezvani, Seyed Ali; Lu, Peixiang

    2017-11-01

    We present a scheme for tomographic imaging of asymmetric molecular orbital based on high-order harmonic generation with a two-color orthogonally polarized multicycle laser field. With the two-dimensional manipulation of the electron trajectories, the electrons can recollide with the target molecule from two noncollinear directions, and then the dipole moment generated from the single direction can be obtained to reconstructed the asymmetric molecular orbital. The recollision is independent from the molecular structure and the angular dependence of the ionization rate in the external field. For this reason, this scheme can avoid the negative effects arising from the modification of the angle-dependent ionization rate induced by Stark shift and be applied to various molecules.

  19. KSC-98pc1160

    NASA Image and Video Library

    1998-09-27

    KENNEDY SPACE CENTER, FLA. -- The Shuttle Carrier Aircraft with orbiter Atlantis on top touches down at the Shuttle Landing Facility. Atlantis returns home after a 10-month stay in the Palmdale, CA, orbiter processing facility undergoing extensive inspections and modifications. They included several upgrades enabling it to support International Space Station missions, such as adding an external airlock for ISS docking missions and installing thinner, lighter thermal protection blankets for weight reduction which will allow it to haul heavier cargo. The flight from Palmdale included a fueling stop in Ft. Hood, TX, and overnight stay at Ft. Campbell, KY. Atlantis will undergo preparations in the Orbiter Processing Facility at KSC for its planned flight in June 1999

  20. KSC-98pc1161

    NASA Image and Video Library

    1998-09-27

    KENNEDY SPACE CENTER, FLA. -- The Shuttle Carrier Aircraft gently lands its piggyback cargo orbiter Atlantis at the Shuttle Landing Facility. Atlantis returns home after a 10-month stay in the Palmdale, CA, orbiter processing facility undergoing extensive inspections and modifications. They included several upgrades enabling it to support International Space Station missions, such as adding an external airlock for ISS docking missions and installing thinner, lighter thermal protection blankets for weight reduction which will allow it to haul heavier cargo. The flight from Palmdale included a fueling stop in Ft. Hood, TX, and overnight stay at Ft. Campbell, KY. Atlantis will undergo preparations in the Orbiter Processing Facility at KSC for its planned flight in June 1999

  1. KSC-98pc1159

    NASA Image and Video Library

    1998-09-27

    KENNEDY SPACE CENTER, FLA. -- The Shuttle Carrier Aircraft with orbiter Atlantis on top arrives at the Shuttle Landing Facility. Atlantis returns home after a 10-month stay in the Palmdale, CA, orbiter processing facility undergoing extensive inspections and modifications. They included several upgrades enabling it to support International Space Station missions, such as adding an external airlock for ISS docking missions and installing thinner, lighter thermal protection blankets for weight reduction which will allow it to haul heavier cargo. The flight from Palmdale included a fueling stop in Ft. Hood, TX, and overnight stay at Ft. Campbell, KY. Atlantis will undergo preparations in the Orbiter Processing Facility at KSC for its planned flight in June 1999

  2. Impact of Swarm GPS receiver updates on POD performance

    NASA Astrophysics Data System (ADS)

    van den IJssel, Jose; Forte, Biagio; Montenbruck, Oliver

    2016-05-01

    The Swarm satellites are equipped with state-of-the-art Global Positioning System (GPS) receivers, which are used for the precise geolocation of the magnetic and electric field instruments, as well as for the determination of the Earth's gravity field, the total electron content and low-frequency thermospheric neutral densities. The onboard GPS receivers deliver high-quality data with an almost continuous data rate. However, the receivers show a slightly degraded performance when flying over the geomagnetic poles and the geomagnetic equator, due to ionospheric scintillation. Furthermore, with only eight channels available for dual-frequency tracking, the amount of collected GPS tracking data is relatively low compared with various other missions. Therefore, several modifications have been implemented to the Swarm GPS receivers. To optimise the amount of collected GPS data, the GPS antenna elevation mask has slowly been reduced from 10° to 2°. To improve the robustness against ionospheric scintillation, the bandwidths of the GPS receiver tracking loops have been widened. Because these modifications were first implemented on Swarm-C, their impact can be assessed by a comparison with the close flying Swarm-A satellite. This shows that both modifications have a positive impact on the GPS receiver performance. The reduced elevation mask increases the amount of GPS tracking data by more than 3 %, while the updated tracking loops lead to around 1.3 % more observations and a significant reduction in tracking losses due to severe equatorial scintillation. The additional observations at low elevation angles increase the average noise of the carrier phase observations, but nonetheless slightly improve the resulting reduced-dynamic and kinematic orbit accuracy as shown by independent satellite laser ranging (SLR) validation. The more robust tracking loops significantly reduce the large carrier phase observation errors at the geomagnetic poles and along the geomagnetic equator and do not degrade the observations at midlatitudes. SLR validation indicates that the updated tracking loops also improve the reduced-dynamic and kinematic orbit accuracy. It is expected that the Swarm gravity field recovery will benefit from the improved kinematic orbit quality and potentially also from the expected improvement of the kinematic baseline determination and the anticipated reduction in the systematic gravity field errors along the geomagnetic equator. Finally, other satellites that carry GPS receivers that encounter similar disturbances might also benefit from this analysis.

  3. STS-68 on Runway with 747 SCA/Columbia Ferry Flyby

    NASA Image and Video Library

    1994-10-11

    The space shuttle Endeavour receives a high-flying salute from its sister shuttle, Columbia, atop NASA's Shuttle Carrier Aircraft, shortly after Endeavor’s landing 11 October 1994, at Edwards, California, to complete mission STS-68. Columbia was being ferried from the Kennedy Space Center, Florida, to Air Force Plant 42, Palmdale, California, where it will undergo six months of inspections, modifications, and systems upgrades. The STS-68 11-day mission was devoted to radar imaging of Earth's geological features with the Space Radar Laboratory. The orbiter is surrounded by equipment and personnel that make up the ground support convoy that services the space vehicles as soon as they land.

  4. STS-68 on Runway with 747 SCA - Columbia Ferry Flyby

    NASA Image and Video Library

    1994-10-11

    The space shuttle Endeavour receives a high-flying salute from its sister shuttle, Columbia, atop NASA's Shuttle Carrier Aircraft, shortly after Endeavor’s landing 11 October 1994, at Edwards, California, to complete mission STS-68. Columbia was being ferried from the Kennedy Space Center, Florida, to Air Force Plant 42, Palmdale, California, where it will undergo six months of inspections, modifications, and systems upgrades. The STS-68 11-day mission was devoted to radar imaging of Earth's geological features with the Space Radar Laboratory. The orbiter is surrounded by equipment and personnel that make up the ground support convoy that services the space vehicles as soon as they land.

  5. Communications systems checkout study

    NASA Technical Reports Server (NTRS)

    Ginter, W. G.

    1972-01-01

    The results and conclusions of an engineering study of Space Station communications subsystem checkout are reported. The primary purpose of the study is to recommend specific guidelines and constraints for the design and utilization of the communications subsystem leading to a practical and effective means of onboard checkout implementation. Major study objectives are as follows: (1) identify candidate communications subsystem checkout concepts, (2) determine implementation impacts of feasible concepts, (3) evaluate practicality and effectiveness of alternative concepts, (4) propose baseline modifications to accommodate preferred concepts, and (5) recommend areas for additional investigation. In addition, study results are interpreted, where appropriate, in terms of their applicability to checkout of Shuttle-Orbiter communications subsystem.

  6. The theory of Enceladus and Dione - An application of computerized algebra in dynamical astronomy

    NASA Technical Reports Server (NTRS)

    Jefferys, W. H.; Ries, L. M.

    1975-01-01

    The orbits of the satellites of the outer planets are poorly known, due to lack of attention over the past half century. We have been developing a new theory of Saturn's satellites Enceladus and Dione which is literal (all constants of integration appear explicitly), canonically invariant (the Hori-Lie method is used), and which correctly handles the eccentricity-type resonance between the two satellites. The algebraic manipulations are being performed using the TRIGMAN formula manipulation language, and the programs have been developed so that with minor modifications they can be used on the Mimas-Tethys and Titan-Hyperion systems.

  7. Systems design study of the Pioneer Venus spacecraft. Appendices to volume 1, sections 8-11 (part 3 of 3). [power subsystem/cost tradeoffs for Venus probe

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Power subsystem cost/weight tradeoffs are discussed for the Venus probe spacecraft. The cost estimations of power subsystem units were based upon DSCS-2, DSP, and Pioneer 10 and 11 hardware design and development and manufacturing experience. Parts count and degree of modification of existing hardware were factored into the estimate of manufacturing and design and development costs. Cost data includes sufficient quantities of units to equip probe bus and orbiter versions. It was based on the orbiter complement of equipment, but the savings in fewer slices for the probe bus balance the cost of the different probe bus battery. The preferred systems for the Thor/Delta and for the Atlas/Centaur are discussed. The weights of the candidate designs were based upon slice or tray weights for functionally equivalent circuitry measured on existing hardware such as Pioneers 10 and 11, Intelsat 3, DSCS-2, or DSP programs. Battery weights were based on measured cell weight data adjusted for case weight or off-the-shelf battery weights. The solar array weight estimate was based upon recent hardware experience on DSCS-2 and DSP arrays.

  8. Using Mars Orbiter Laser Altimeter (MOLA) Data to Assess Impact Crater Modification in the Arrhenius Region of Mars

    NASA Technical Reports Server (NTRS)

    Garvin, J. B.; Grosfils, E. B.; Sakimoto, S. E. H.

    2000-01-01

    This study combines MOLA altimetry with photographic imagery to begin assessing the extent to which sedimentary and volcanic processes have affected impact crater morphology in the Arrhenius region of Mars.

  9. A Scheme for the Evaluation of Electron Delocalization and Conjugation Efficiency in Linearly π-Conjugated Systems.

    PubMed

    Bruschi, Maurizio; Limacher, Peter A; Hutter, Jürg; Lüthi, Hans Peter

    2009-03-10

    In this study, we present a scheme for the evaluation of electron delocalization and conjugation efficiency in lineraly π-conjugated systems. The scheme, based on the natural bond orbital theory, allows monitoring the evolution of electron delocalization along an extended conjugation path as well as its response to chemical modification. The scheme presented is evaluated and illustrated by means of a computational investigation of π-conjugation in all-trans polyacetylene [PA; H(-CH═CH)n-H], polydiacetylene [PDA, H(-C≡C-CH═CH)n-H], and polytriacetylene [PTA, H(-C≡C-CH═CH-C≡C)n-H] with up to 180 carbon atoms, all related by the number of ethynyl units incorporated in the chain. We are able to show that for short oligomers the incorporation of ethynyl spacers into the PA chain increases the π-delocalization energy, but, on the other hand, reduces the efficiency with which π-electron delocalization is promoted along the backbone. This explains the generally shorter effective conjugation lengths observed for the properties of the polyeneynes (PDA and PTA) relative to the polyenes (PA). It will also be shown that the reduced conjugation efficiency, within the NBO-based model presented in this work, can be related to the orbital interaction pattern along the π-conjugated chain. We will show that the orbital interaction energy pattern is characteristic for the type and the length of the backbone and may therefore serve as a descriptor for linearly π-conjugated chains.

  10. Design for effective development and prototyping of the HL-20

    NASA Astrophysics Data System (ADS)

    Urie, David M.; Floreck, Paul A.; McMorris, John A.; Elvin, John D.

    1993-10-01

    A feasibility study of the HL-20 personnel launch system (PLS) concept was conducted by a team which focused on creating a PLS design approach and an accelerated development plan consistent with the historical 'Skunk Works' approach to rapid prototyping. Technical design, manufacturing, system testing, and operations and support elements of the predefined baseline concept were evaluated. An initial phase program, featuring a concurrent system test during design and development, leading to the orbital flight of an unmanned HL-20 prototype on a Titan III launch system, was prescribed. A second-phase development and manufacturing plan leading to system operational status was also formulated. Baseline design feature modifications were made when necessary, without compromise to performance, to satisfy the prototype development plan. Technical design details and off-the-shelf hardware candidates were also identified for several subsystems, including the launch-system interface adapter/emergency escape system. The technical feasibility of the system and applicability of the Skunk Works approach to development of the HL-20/PLS were verified.

  11. Advanced Communications Technology Satellite (ACTS) Used for Inclined Orbit Operations

    NASA Technical Reports Server (NTRS)

    Bauer, Robert A.

    2000-01-01

    The Advanced Communications Technology Satellite (ACTS) is operated by the NASA Glenn Research Center at Lewis Field 24 hours a day, 7 days a week. ACTS, which was launched in September 1993, is in its 7th year of operations, far exceeding the system s planned 2 years of operations and 4 years of designed mission life. After 5 successful years of operating as a geostationary satellite, the spacecraft s North-South stationkeeping was discontinued in August 1998. The system is now operating in an inclined orbit that increases at a rate of 0.8 /yr. With only scarce fuel remaining, operating in this mode extends the usage of the still totally functional payload. Although tracking systems are now needed on the experimenter Earth stations, experiment operations have continued with very little disruption. This is the only known geosynchronous Ka-band (30/20 GHz) spot-beam satellite operating in an inclined orbit. The project began its transition from geostationary operations to inclined operations in August 1998. This did not interrupt operations and was transparent to the experimenters on the system. For the space segment, new daily procedures were implemented to maintain the pointing of the system s narrow 0.3 spot beams while the spacecraft drifts in the North-South direction. For the ground segment, modifications were designed, developed, and fielded for the three classes of experimenter Earth stations. With the next generation of commercial satellite systems still being developed, ACTS remains the only operational testbed for Ka-band geosynchronous satellite communications over the Western hemisphere. Since inclined orbit operations began, the ACTS experiments program has supported 43 investigations by industry, Government, and academic organizations, as well as four demonstrations. The project s goals for inclined-orbit operations now reflect a narrower focus in the types of experiments that will be done. In these days of "faster, better, cheaper," NASA is seeking to gain greater relevance to the agency s mission from these experiments. One area that is of much interest both to NASA and the commercial world is the investigation of protocol issues related to the interoperability of satellites with terrestrial networks, such as Transmission Control Protocol/Internet Protocol (TCP/IP) and Asynchronous Transfer Mode (ATM) over wideband satellites. Other experiment areas of interest are supporting the U.S. Government and NASA as they begin using commercial space assets to meet their communications needs, evaluating issues related to operating a spot-beam satellite in inclined orbit, and evaluating new Ka-band hardware that requires a satellite link. ACTS is now in its last year of operations. Operations are planned through June 2000, when after 81 months of operations, this very successful spacecraft will be superorbited and made inert.

  12. Reverse Kinematic Analysis and Uncertainty Analysis of the Space Shuttle AFT Propulsion System (APS) POD Lifting Fixture

    NASA Technical Reports Server (NTRS)

    Brink, Jeffrey S.

    2005-01-01

    The space shuttle Aft Propulsion System (APS) pod requires precision alignment to be installed onto the orbiter deck. The Ground Support Equipment (GSE) used to perform this task cannot be manipulated along a single Cartesian axis without causing motion along the other Cartesian axes. As a result, manipulations required to achieve a desired motion are not intuitive. My study calculated the joint angles required to align the APS pod, using reverse kinematic analysis techniques. Knowledge of these joint angles will allow the ground support team to align the APS pod more safely and efficiently. An uncertainty analysis was also performed to estimate the accuracy associated with this approach and to determine whether any inexpensive modifications can be made to further improve accuracy.

  13. Project EGRESS: Earthbound Guaranteed Reentry from Space Station. the Design of an Assured Crew Recovery Vehicle for the Space Station

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Unlike previously designed space-based working environments, the shuttle orbiter servicing the space station will not remain docked the entire time the station is occupied. While an Apollo capsule was permanently available on Skylab, plans for Space Station Freedom call for a shuttle orbiter to be docked at the space station for no more than two weeks four times each year. Consideration of crew safety inspired the design of an Assured Crew Recovery Vehicle (ACRV). A conceptual design of an ACRV was developed. The system allows the escape of one or more crew members from Space Station Freedom in case of emergency. The design of the vehicle addresses propulsion, orbital operations, reentry, landing and recovery, power and communication, and life support. In light of recent modifications in space station design, Project EGRESS (Earthbound Guaranteed ReEntry from Space Station) pays particular attention to its impact on space station operations, interfaces and docking facilities, and maintenance needs. A water-landing medium-lift vehicle was found to best satisfy project goals of simplicity and cost efficiency without sacrificing safety and reliability requirements. One or more seriously injured crew members could be returned to an earth-based health facility with minimal pilot involvement. Since the craft is capable of returning up to five crew members, two such permanently docked vehicles would allow a full evacuation of the space station. The craft could be constructed entirely with available 1990 technology, and launched aboard a shuttle orbiter.

  14. WHITE-LIGHT FLARES ON CLOSE BINARIES OBSERVED WITH KEPLER

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gao, Qing; Xin, Yu; Liu, Ji-Feng

    2016-06-01

    Based on Kepler data, we present the results of a search for white light flares on 1049 close binaries. We identify 234 flare binaries, of which 6818 flares are detected. We compare the flare-binary fraction in different binary morphologies (“detachedness”). The result shows that the fractions in over-contact and ellipsoidal binaries are approximately 10%–20% lower than those in detached and semi-detached systems. We calculate the binary flare activity level (AL) of all the flare binaries, and discuss its variations along the orbital period ( P {sub orb}) and rotation period ( P {sub rot}, calculated for only detached binaries). Wemore » find that the AL increases with decreasing P {sub orb} or P {sub rot}, up to the critical values at P {sub orb} ∼ 3 days or P {sub rot} ∼ 1.5 days, and thereafter the AL starts decreasing no matter how fast the stars rotate. We examine the flaring rate as a function of orbital phase in two eclipsing binaries on which a large number of flares are detected. It appears that there is no correlation between flaring rate and orbital phase in these two binaries. In contrast, when we examine the function with 203 flares on 20 non-eclipse ellipsoidal binaries, bimodal distribution of amplitude-weighted flare numbers shows up at orbital phases 0.25 and 0.75. Such variation could be larger than what is expected from the cross section modification.« less

  15. Magnetic tweezers for the measurement of twist and torque.

    PubMed

    Lipfert, Jan; Lee, Mina; Ordu, Orkide; Kerssemakers, Jacob W J; Dekker, Nynke H

    2014-05-19

    Single-molecule techniques make it possible to investigate the behavior of individual biological molecules in solution in real time. These techniques include so-called force spectroscopy approaches such as atomic force microscopy, optical tweezers, flow stretching, and magnetic tweezers. Amongst these approaches, magnetic tweezers have distinguished themselves by their ability to apply torque while maintaining a constant stretching force. Here, it is illustrated how such a "conventional" magnetic tweezers experimental configuration can, through a straightforward modification of its field configuration to minimize the magnitude of the transverse field, be adapted to measure the degree of twist in a biological molecule. The resulting configuration is termed the freely-orbiting magnetic tweezers. Additionally, it is shown how further modification of the field configuration can yield a transverse field with a magnitude intermediate between that of the "conventional" magnetic tweezers and the freely-orbiting magnetic tweezers, which makes it possible to directly measure the torque stored in a biological molecule. This configuration is termed the magnetic torque tweezers. The accompanying video explains in detail how the conversion of conventional magnetic tweezers into freely-orbiting magnetic tweezers and magnetic torque tweezers can be accomplished, and demonstrates the use of these techniques. These adaptations maintain all the strengths of conventional magnetic tweezers while greatly expanding the versatility of this powerful instrument.

  16. Fast Low-Current Spin-Orbit-Torque Switching of Magnetic Tunnel Junctions through Atomic Modifications of the Free-Layer Interfaces

    NASA Astrophysics Data System (ADS)

    Shi, Shengjie; Ou, Yongxi; Aradhya, S. V.; Ralph, D. C.; Buhrman, R. A.

    2018-01-01

    Future applications of spin-orbit torque will require new mechanisms to improve the efficiency of switching nanoscale magnetic tunnel junctions (MTJs), while also controlling the magnetic dynamics to achieve fast nanosecond-scale performance with low-write-error rates. Here, we demonstrate a strategy to simultaneously enhance the interfacial magnetic anisotropy energy and suppress interfacial spin-memory loss by introducing subatomic and monatomic layers of Hf at the top and bottom interfaces of the ferromagnetic free layer of an in-plane magnetized three-terminal MTJ device. When combined with a β -W spin Hall channel that generates spin-orbit torque, the cumulative effect is a switching current density of 5.4 ×106 A /cm2 .

  17. Properties of Augmented Kohn-Sham Potential for Energy as Simple Sum of Orbital Energies.

    PubMed

    Zahariev, Federico; Levy, Mel

    2017-01-12

    A recent modification to the traditional Kohn-Sham method ( Levy , M. ; Zahariev , F. Phys. Rev. Lett. 2014 , 113 , 113002 ; Levy , M. ; Zahariev , F. Mol. Phys. 2016 , 114 , 1162 - 1164 ), which gives the ground-state energy as a direct sum of the occupied orbital energies, is discussed and its properties are numerically illustrated on representative atoms and ions. It is observed that current approximate density functionals tend to give surprisingly small errors for the highest occupied orbital energies that are obtained with the augmented potential. The appropriately shifted Kohn-Sham potential is the basic object within this direct-energy Kohn-Sham method and needs to be approximated. To facilitate approximations, several constraints to the augmented Kohn-Sham potential are presented.

  18. KSC-98pc1162

    NASA Image and Video Library

    1998-09-27

    KENNEDY SPACE CENTER, FLA. -- The Shuttle Carrier Aircraft rolls to a stop with its piggyback cargo orbiter Atlantis at the Shuttle Landing Facility. In the background is the Vehicle Assembly Building. Atlantis returns home after a 10-month stay in the Palmdale, CA, orbiter processing facility undergoing extensive inspections and modifications. They included several upgrades enabling it to support International Space Station missions, such as adding an external airlock for ISS docking missions and installing thinner, lighter thermal protection blankets for weight reduction which will allow it to haul heavier cargo. The flight from Palmdale included a fueling stop in Ft. Hood, TX, and overnight stay at Ft. Campbell, KY. Atlantis will undergo preparations in the Orbiter Processing Facility at KSC for its planned flight in June 1999

  19. KSC-98pc1163

    NASA Image and Video Library

    1998-09-27

    KENNEDY SPACE CENTER, FLA. -- Stairs are rolled to the forward opening of the Shuttle Carrier Aircraft with its piggyback cargo, the orbiter Atlantis after it rolls to a stop at the Shuttle Landing Facility. Atlantis returns home after a 10-month stay in the Palmdale, CA, orbiter processing facility undergoing extensive inspections and modifications. They included several upgrades enabling it to support International Space Station missions, such as adding an external airlock for ISS docking missions and installing thinner, lighter thermal protection blankets for weight reduction which will allow it to haul heavier cargo. The flight from Palmdale included a fueling stop in Ft. Hood, TX, and overnight stay at Ft. Campbell, KY. Atlantis will undergo preparations in the Orbiter Processing Facility at KSC for its planned flight in June 1999

  20. Planning satellite communication services and spectrum-orbit utilization

    NASA Technical Reports Server (NTRS)

    Sawitz, P. H.

    1982-01-01

    The relationship between approaches to planning satellite communication services and spectrum-orbit utilization is considered, with emphasis on the fixed-satellite and the broadcasting-satellite services. It is noted that there are several possible approaches to planning space services, differing principally in the rigidity with which technical parameters are prescribed, in the time for which a plan remains in force, and in the procedures adopted for implementation and modifications. With some planning approaches, spectrum-orbit utilization is fixed at the time the plan is made. Others provide for greater flexibility by making it possible to postpone some decisions on technical parameters. In addition, the two political questions of what is equitable access and how it can be guaranteed in practice play an important role.

  1. Modified lateral orbital wall decompression in Graves' orbitopathy using computer-assisted planning.

    PubMed

    Spalthoff, S; Jehn, P; Zimmerer, R; Rana, M; Gellrich, N-C; Dittmann, J

    2018-02-01

    Graves' orbitopathy, a condition seen in the autoimmune syndrome Graves' disease, affects the fatty tissue and muscles inside the orbit. Graves' orbitopathy is associated with increasing exophthalmos and sometimes leads to compressive dysthyroid optic neuropathy, resulting in progressive vision loss. Dysthyroid compressive optic neuropathy, functional problems, and cosmetic problems are the main indications for surgical decompression of the orbit, especially if conservative treatment has not led to a reduction in symptoms. Many surgical techniques are described in the literature. This article presents a modification of the lateral orbital wall osteotomy, involving the rotation and reduction of the osteotomized bone segment using preoperative planning, intraoperative computed navigation, and piezoelectric surgery. This new method combines the advantages of different techniques and appears to be a valid approach to the treatment of severe cases of Graves' orbitopathy. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  2. Lunar lander stage requirements based on the Civil Needs Data Base

    NASA Technical Reports Server (NTRS)

    Mulqueen, John A.

    1992-01-01

    This paper examines the lunar lander stages that will be necessary for the future exploration and development of the Moon. Lunar lander stage sizing is discussed based on the projected lunar payloads listed in the Civil Needs Data Base. Factors that will influence the lander stage design are identified and discussed. Some of these factors are (1) lunar orbiting and lunar surface lander bases; (2) implications of direct landing trajectories and landing from a parking orbit; (3) implications of landing site and parking orbit; (4) implications of landing site and parking orbit selection; (5) the use of expendable and reusable lander stages; and (6) the descent/ascent trajectories. Data relating the lunar lander stage design requirements to each of the above factors and others are presented in parametric form. These data will provide useful design data that will be applicable to future mission model modifications and design studies.

  3. Environmental monitoring of the orbiter payload bay and Orbiter Processing Facilities

    NASA Technical Reports Server (NTRS)

    Bartelson, D. W.; Johnson, A. M.

    1985-01-01

    Contamination control in the Orbiter Processing Facility (OPF) is studied. The clean level required in the OPF is generally clean, which means no residue, dirt, debris, or other extraneous contamination; various methods of maintaining this level of cleanliness are described. The monitoring and controlling of the temperature, relative humidity, and air quality in the OPF are examined. Additional modifications to the OPF to improve contamination control are discussed. The methods used to maintain the payload changeout room at a level of visually clean, no particulates are to be detected by the unaided eye, are described. The payload bay (PLB) must sustain the cleanliness level required for the specific Orbiter's mission; the three levels of clean are defined as: (1) standard, (2) sensitive, and (3) high sensitive. The cleaning and inspection verification required to achieve the desired cleanliness level on a variety of PLB surface types are examined.

  4. KSC-08pd1859

    NASA Image and Video Library

    2008-07-01

    CAPE CANAVERAL, Fla. – In the Assembly and Refurbishment Facility at NASA's Kennedy Space Center, a crane is lowered over the aft skirt for the Ares 1-X rocket. The segment is being lifted into a machine shop work stand for drilling modifications. The modifications will prepare it for the installation of the auxiliary power unit controller, the reduced-rate gyro unit, the booster decelerator motors and the booster tumble motors. Ares I is an in-line, two-stage rocket that will transport the Orion crew exploration vehicle to low-Earth orbit. Ares I-X is a test rocket. The Ares I first stage will be a five-segment solid rocket booster based on the four-segment design used for the shuttle. Ares I’s fifth booster segment allows the launch vehicle to lift more weight and reach a higher altitude before the first stage separates from the upper stage, which ignites in midflight to propel the Orion spacecraft to Earth orbit. Photo credit: NASA/Jim Grossmann

  5. An analysis of the low-earth-orbit communications environment

    NASA Astrophysics Data System (ADS)

    Diersing, Robert Joseph

    Advances in microprocessor technology and availability of launch opportunities have caused interest in low-earth-orbit satellite based communications systems to increase dramatically during the past several years. In this research the capabilities of two low-cost, store-and-forward LEO communications satellites operating in the public domain are examined--PACSAT-1 (operated by the Radio Amateur Satellite Corporation) and UoSAT-3 (operated by the University of Surrey, England, Electrical Engineering Department). The file broadcasting and file transfer facilities are examined in detail and a simulation model of the downlink traffic pattern is developed. The simulator will aid the assessment of changes in design and implementation for other systems. The development of the downlink traffic simulator is based on three major parts. First, is a characterization of the low-earth-orbit operating environment along with preliminary measurements of the PACSAT-1 and UoSAT-3 systems including: satellite visibility constraints on communications, monitoring equipment configuration, link margin computations, determination of block and bit error rates, and establishing typical data capture rates for ground stations using computer-pointed directional antennas and fixed omni-directional antennas. Second, arrival rates for successful and unsuccessful file server connections are established along with transaction service times. Downlink traffic has been further characterized by measuring: frame and byte counts for all data-link layer traffic; 30-second interval average response time for all traffic and for file server traffic only; file server response time on a per-connection basis; and retry rates for information and supervisory frames. Finally, the model is verified by comparison with measurements of actual traffic not previously used in the model building process. The simulator is then used to predict operation of the PACSAT-1 satellite with modifications to the original design.

  6. Preliminary analysis of remote infrared imagery of shuttle during entry: An aerothermodynamic flight experiment

    NASA Technical Reports Server (NTRS)

    Swenson, B. L.; Edsinger, L. E.

    1977-01-01

    The preliminary feasibility of remote high-resolution infrared imagery of the space shuttle orbiter lower surface during entry to obtain accurate measurements of aerodynamic heat transfer to that vehicle was examined. In general, it was determined that such such images can be taken from an existing aircraft/telescope system (the C-141 AIRO) with a minimum modification or addition of systems using available technology. These images will have a spatial resolution of about 0.3 m and a temperature resolution much better than 2.5 percent. The data from these images will be at conditions and at a scale not reproducible in ground based facilities and should aid in the reduction of the prudent factors of safety required to account for phenomenological uncertainties on the thermal protection system design. Principal phenomena to be observed include laminar heating, boundary-layer transition, turbulent heating, surface catalysis, and flow separation and reattachment.

  7. Near Earth Asteroids- Prospection, Orbit Modification and Mining

    NASA Astrophysics Data System (ADS)

    Grandl, W.; Bazso, A.

    2014-04-01

    The number of known Near Earth Asteroids (NEAs) has increased continuously during the last decades. Now we understand the role of asteroid impacts for the evolution of life on Earth. To ensure that mankind will survive in the long run, we have to face the "asteroid threat" seriously. On one hand we will have to develop methods of detection and deflection for Hazardous Asteroids, on the other hand we can use these methods to modify their orbits and exploit their resources. Rare-earth elements, rare metals like platinum group elements, etc. may be extracted more easily from NEAs than from terrestrial soil, without environmental pollution or political and social problems. In a first step NEAs, which are expected to contain resources like nickel-iron, platinum group metals or rare-earth elements, will be prospected by robotic probes. Then a number of asteroids with a minimum bulk density of 2 g/cm^3 and a diameter of 150 to 500 m will be selected for mining. Given the long duration of an individual mission time of 10-20 years, the authors propose a "pipeline" concept. While the observation of NEAs can be done in parallel, the precursor missions of the the next phase can be launched in short intervals, giving time for technical corrections and upgrades. In this way a continuous data flow is established and there are no idle times. For our purpose Potentially Hazardous Asteroids (PHAs) seem to be a favorable choice for the following reasons: They have frequent closeencounters to Earth, their minimum orbit intersection distance is less than 0.05 AU (Astronomic Units) and they have diameters exceeding 150 meters. The necessary velocity change (delta V) for a spaceship is below 12 km/s to reach the PHA. The authors propose to modify the orbits of the chosen PHAs by orbital maneuvers from solar orbits to stable Earth orbits beyond the Moon. To change the orbits of these celestial bodies it is necessary to develop advanced propulsion systems. They must be able to deliver high thrust and specific impulse to move the huge masses of the asteroids. Such a propulsion system could be the Bussard Fusion System, also known as the quiet-electricdischarge (QED) engine. It uses electrostatic fusion devices to generate electrical power. The fuel consists of Deuterium and Helium3 that are fusing to Helium4 plus protons releasing 18.3 MeV of energy per reaction. The charged protons escape from the confinement; their kinetic energy can be converted to electricity or be used directly as a plasma beam for generating thrust. For the reaction a specific energy of 3.5x1014 Joule/kg can be computed, i.e. orders-ofmagnitude higher than for any existing propulsion system. As an example we take the Asteroid with the designation 2008 EV5. It is classified as an Aten group asteroid with a mean diameter of 450 meters and belongs to spectral type S (stony asteroids). Our mass estimate (using a bulk density of 3 g/cm^3) is 1.4x1011 kg. To transfer 2008 EV5 to an Earth-like orbit the energy required is estimated to be in the order of 2.8x1018 Joule. This is the difference in Kepler energy between the NEA's current orbit and the Earth's orbit around the sun. Using the Bussard Fusion System the amount of fuel would be approx. 8000 kg of Helium3. To move an asteroid by remote control the authors propose to design unmanned space tugs which are propelled by Bussard Fusion Engines. A pair of space tugs is docked to each asteroid using drilling anchors. The fusion engines of the tugs then apply the thrust forces for the maneuvers. The first tug, which carries the main fuel quantity, applies the primary force for the orbital maneuvers. The second one adjust the flight track by short engine thrusts.

  8. Autonomous Medical Care for Exploration Class Space Missions

    NASA Technical Reports Server (NTRS)

    Hamilton, Douglas; Smart, Kieran; Melton, Shannon; Polk, James D.; Johnson-Throop, Kathy

    2007-01-01

    The US-based health care system of the International Space Station (ISS) contains several subsystems, the Health Maintenance System, Environmental Health System and the Countermeasure System. These systems are designed to provide primary, secondary and tertiary medical prevention strategies. The medical system deployed in Low Earth Orbit (LEO) for the ISS is designed to enable a "stabilize and transport" concept of operations. In this paradigm, an ill or injured crewmember would be rapidly evacuated to a definitive medical care facility (DMCF) on Earth, rather than being treated for a protracted period on orbit. The medical requirements of the short (7 day) and long duration (up to 6 months) exploration class missions to the Moon are similar to LEO class missions with the additional 4 to 5 days needed to transport an ill or injured crewmember to a DCMF on Earth. Mars exploration class missions are quite different in that they will significantly delay or prevent the return of an ill or injured crewmember to a DMCF. In addition the limited mass, power and volume afforded to medical care will prevent the mission designers from manifesting the entire capability of terrestrial care. NASA has identified five Levels of Care as part of its approach to medical support of future missions including the Constellation program. In order to implement an effective medical risk mitigation strategy for exploration class missions, modifications to the current suite of space medical systems may be needed, including new Crew Medical Officer training methods, treatment guidelines, diagnostic and therapeutic resources, and improved medical informatics.

  9. GEOS axial booms

    NASA Technical Reports Server (NTRS)

    Schmidt, G. K.

    1979-01-01

    A booms and mechanisms subsystem was designed, developed, and qualified for the geostationary scientific satellite GEOS. Part of this subsystem consist of four axial booms consisting of one pair of 1 m booms and one pair of 2.5 m booms. Each of these booms is carrying one bird cage electric field sensor. Alignment accuracy requirements led to a telescopic type solution. Deployment is performed by pressurized nitrogen. At deployment in orbit two of these booms showed some anomalies and one of these two deployed only about 80%. Following this malfunction a detailed failure investigation was performed resulting in a design modification of some critical components as release mechanism, guide sleeves of the telescopic elements, and pressure system.

  10. IMPACT fragmentation model developments

    NASA Astrophysics Data System (ADS)

    Sorge, Marlon E.; Mains, Deanna L.

    2016-09-01

    The IMPACT fragmentation model has been used by The Aerospace Corporation for more than 25 years to analyze orbital altitude explosions and hypervelocity collisions. The model is semi-empirical, combining mass, energy and momentum conservation laws with empirically derived relationships for fragment characteristics such as number, mass, area-to-mass ratio, and spreading velocity as well as event energy distribution. Model results are used for several types of analysis including assessment of short-term risks to satellites from orbital altitude fragmentations, prediction of the long-term evolution of the orbital debris environment and forensic assessments of breakup events. A new version of IMPACT, version 6, has been completed and incorporates a number of advancements enabled by a multi-year long effort to characterize more than 11,000 debris fragments from more than three dozen historical on-orbit breakup events. These events involved a wide range of causes, energies, and fragmenting objects. Special focus was placed on the explosion model, as the majority of events examined were explosions. Revisions were made to the mass distribution used for explosion events, increasing the number of smaller fragments generated. The algorithm for modeling upper stage large fragment generation was updated. A momentum conserving asymmetric spreading velocity distribution algorithm was implemented to better represent sub-catastrophic events. An approach was developed for modeling sub-catastrophic explosions, those where the majority of the parent object remains intact, based on estimated event energy. Finally, significant modifications were made to the area-to-mass ratio distribution to incorporate the tendencies of different materials to fragment into different shapes. This ability enabled better matches between the observed area-to-mass ratios and those generated by the model. It also opened up additional possibilities for post-event analysis of breakups. The paper will discuss a number of the modifications that have been made to improve IMPACT and why these modifications were made. Comparisons between observational data and the IMPACT predictions will be discussed in the context of these model revisions and the overall behavior of model results. A number of future areas of investigation that were uncovered in the process of the analysis efforts will also be reviewed.

  11. Autonomous Formation Flying from the Ground to Flight

    NASA Technical Reports Server (NTRS)

    Chapman, Keith B.; Dell, Gregory T.; Rosenberg, Duane L.; Bristow, John

    1999-01-01

    The cost of on-orbit operations remains a significant and increasingly visible concern in the support of satellite missions. Headway has been made in automating some ground operations; however, increased mission complexity and more precise orbital constraints have compelled continuing human involvement in mission design and maneuver planning operations. AI Solutions, Inc. in cooperation with the National Aeronautics and Space Administration's (NASA) Goddard Space Flight Center (GSFC) has tackled these more complex problems through the development of AutoCon(TM) as a tool for an automated solution. NASA is using AutoCon(TM) to automate the maneuver planning for the Earth Orbiter-1 (EO-1) mission. AutoCon(TM) was developed originally as a ground system tool. The EO-1 mission will be using a scaled version of AutoCon(TM) on-board the EO-1 satellite to command orbit adjustment maneuvers. The flight version of AutoCon(TM) plans maneuvers based on formation flying algorithms developed by GSFC, JPL, and other industry partners. In its fully autonomous mode, an AutoCon(TM) planned maneuver will be executed on-board the satellite without intervention from the ground. This paper describes how AutoCon(TM) automates maneuver planning for the formation flying constraints of the EO-1 mission. AutoCon(TM) was modified in a number of ways to automate the maneuver planning on-board the satellite. This paper describes how the interface and functionality of AutoCon(TM) were modified to support the on-board system. A significant component of this modification was the implementation of a data smoother, based on a Kalman filter, that ensures that the spacecraft states estimated by an on-board GPS receiver are as accurate as possible for maneuver planning. This paper also presents the methodology used to scale the AutoCon(TM) functionality to fit and execute on the flight hardware. This paper also presents the modes built into the system that allow the incremental phasing in of autonomy. New technologies for autonomous operations are usually received with significant, and probably appropriate, trepidation. A number of safeguards have been designed in both AutoCon(TM) and the interfacing systems to alleviate the potential of mission-impacting anomalies from the on-board autonomous system. This paper describes the error checking, input data integrity validation, and limits set on maneuvers in AutoCon(TM) and the on-board system.

  12. Water Phase Change Heat Exchanger System Level Analysis for Low Lunar Orbit

    NASA Technical Reports Server (NTRS)

    Navarro, Moses; Ungar, Eugene; Sheth, Rubik; Hansen, Scott

    2016-01-01

    In low Lunar orbit (LLO) the thermal environment is cyclic - extremely cold in the eclipse and as warm as room temperature near the subsolar point. Phase change material heat exchangers (PCHXs) are the best option for long term missions in these environments. The Orion spacecraft will use a n-pentadecane wax PCHX for its envisioned mission to LLO. Using water as a PCM material is attractive because its higher heat of fusion and greater density result in a lighter, more compact PCHX. To assess the use of a water PCHX for a human spacecraft in a circular LLO, a system level analysis was performed for the Orion spacecraft. Three cases were evaluated: 1) A one-to-one replacement of the wax PCHX on the internal thermal control loop with a water PCHX (including the appropriate control modifications), 2) reducing the radiator return setpoint temperature below Orion's value to enhance PCHX freezing, and 3) placing the water PCM on the external loop. The model showed that the water PCHX could not be used as a drop-in replacement for the wax PCHX. It did not freeze fully during the eclipse owing to its low freezing point. To obtain equivalent performance, 40% more radiator area than the Orion baseline was required. The study shows that, although water PCHXs are attractive at a component level, system level effects mean that they are not the best choice for LLO.

  13. HD 156324: a tidally locked magnetic triple spectroscopic binary with a disrupted magnetosphere

    NASA Astrophysics Data System (ADS)

    Shultz, M.; Rivinius, Th; Wade, G. A.; Alecian, E.; Petit, V.

    2018-03-01

    HD 156324 is an SB3 (B2V/B5V/B5V) system in the Sco OB4 association. The He-strong primary possesses both a strong magnetic field and Hα emission believed to originate in its centrifugal magnetosphere. We analyse a large spectroscopic and high-resolution spectropolarimetric data set. The radial velocities (RVs) indicate that the system is composed of two subsystems, which we designate A and B. Period analysis of the RVs of the three components yields orbital periods Porb = 1.5806(1) d for the Aa and Ab components, and Porb = 6.67(2) d for the B component, a PGa star. Period analysis of the longitudinal magnetic field 〈Bz〉 and Hα equivalent widths, which should both be sensitive to the rotational period Prot of the magnetic Aa component, both yield ˜1.58 d. Since Porb = Prot Aa and Ab must be tidally locked. Consistent with this, the orbit is circularized, and the rotational and orbital inclinations are identical within uncertainty, as are the semimajor axis and the Kepler corotation radius. The star's Hα emission morphology differs markedly from both theoretical and observational expectations in that there is only one, rather than two, emission peaks. We propose that this unusual morphology may be a consequence of modification of the gravitocentrifugal potential by the presence of the close stellar companion. We also obtain upper limits on the magnetic dipole strength Bd for the Ab and B components, respectively, finding Bd < 2.6 and <0.7 kG.

  14. Rendezvous missions with minimoons from L1

    NASA Astrophysics Data System (ADS)

    Chyba, M.; Haberkorn, T.; Patterson, G.

    2014-07-01

    We propose to present asteroid capture missions with the so-called minimoons. Minimoons are small asteroids that are temporarily captured objects on orbits in the Earth-Moon system. It has been suggested that, despite their small capture probability, at any time there are one or two meter diameter minimoons, and progressively greater numbers at smaller diameters. The minimoons orbits differ significantly from elliptical orbits which renders a rendezvous mission more challenging, however they offer many advantages for such missions that overcome this fact. First, they are already on geocentric orbits which results in short duration missions with low Delta-v, this translates in cost efficiency and low-risk targets. Second, beside their close proximity to Earth, an advantage is their small size since it provides us with the luxury to retrieve the entire asteroid and not only a sample of material. Accessing the interior structure of a near-Earth satellite in its morphological context is crucial to an in-depth analysis of the structure of the asteroid. Historically, 2006 RH120 is the only minimoon that has been detected but work is ongoing to determine which modifications to current observation facilities is necessary to provide detection algorithm capabilities. In the event that detection is successful, an efficient algorithm to produce a space mission to rendezvous with the detected minimoon is highly desirable to take advantage of this opportunity. This is the main focus of our work. For the design of the mission we propose the following. The spacecraft is first placed in hibernation on a Lissajoux orbit around the liberation point L1 of the Earth-Moon system. We focus on eight-shaped Lissajoux orbits to take advantage of the stability properties of their invariant manifolds for our transfers since the cost to minimize is the spacecraft fuel consumption. Once a minimoon has been detected we must choose a point on its orbit to rendezvous (in position and velocities) with the spacecraft. This is determined using a combination of distance between the minimoon's orbit to L1 and its energy level with respect to the Lissajoux orbit on which the spacecraft is hibernating. Once the spacecraft rendezvous with the minimoon, it will escort the temporarily captured object to analyze it until the withdrawal time when the spacecraft exits the orbit to return to its hibernating location awaiting for another minimoon to be detected. The entire mission including the return portion can be stated as an optimal control problem, however we choose to break it into smaller sub-problems as a first step to be refined later. To model our control system, we use the circular three-body problem since it provides a good approximation in the vicinity of the Earth-Moon dynamics. Expansion to more refined models will be considered once the problem has been solved for this first approximation. The problem is solved in several steps. First, we consider the time minimal problem since we will use a multiple of it for the minimal fuel consumption problem with fixed time. The techniques used to produce the transfers involve an indirect method based on the necessary optimality condition of the Pontriagyn maximum principle coupled with a continuation method to address the sensitivity of the numerical algorithm to initial values. Time local optimality is verified by computing the Jacobi fields of the Hamiltonian system associated to our optimal control problem to check the second-order conditions of optimality and determine the non-existence of conjugate points.

  15. KSC-07pd1811

    NASA Image and Video Library

    2007-07-08

    KENNEDY SPACE CENTER, FLA. -- The payload canister is lifted off its transporter up to the payload changeout room. Inside the canister are the S5 truss, SPACEHAB module and external stowage platform 3, the payload for mission STS-118. The red umbilical lines are still attached. The payloads will be transferred inside the changeout room to wait for Space Shuttle Endeavour to arrive at the pad. The changeout room is the enclosed, environmentally controlled portion of the rotating service structure that supports cargo delivery to the pad and subsequent vertical installation into the orbiter payload bay. The mission will be Endeavour's first flight in more than four years. The shuttle has undergone extensive modifications, including the addition of safety upgrades already added to shuttles Discovery and Atlantis. Endeavour also features new hardware, such as the Station-to-Shuttle Power Transfer System that will allow the docked shuttle to draw electrical power from the station and extend its visits to the orbiting lab. Space Shuttle Endeavour is targeted for launch on Aug. 7 from Launch Pad 39A. Photo credit: NASA/Kim Shiflett

  16. KSC-07pd1813

    NASA Image and Video Library

    2007-07-08

    KENNEDY SPACE CENTER, FLA. -- On Launch Pad 39A, the payload canister is lifted up to the payload changeout room. Inside the canister are the S5 truss, SPACEHAB module and external stowage platform 3, the payload for mission STS-118. The red umbilical lines are still attached. The payloads will be transferred inside the changeout room to wait for Space Shuttle Endeavour to arrive at the pad. The changeout room is the enclosed, environmentally controlled portion of the rotating service structure that supports cargo delivery to the pad and subsequent vertical installation into the orbiter payload bay. The mission will be Endeavour's first flight in more than four years. The shuttle has undergone extensive modifications, including the addition of safety upgrades already added to shuttles Discovery and Atlantis. Endeavour also features new hardware, such as the Station-to-Shuttle Power Transfer System that will allow the docked shuttle to draw electrical power from the station and extend its visits to the orbiting lab. Space Shuttle Endeavour is targeted for launch on Aug. 7 from Launch Pad 39A. Photo credit: NASA/Kim Shiflett

  17. Project EGRESS: The design of an assured crew return vehicle for the space station

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Keeping preliminary studies by NASA in mind, an Assured Crew Return Vehicle (ACRV) was developed. The system allows the escape of one or more crew members from Space Station Freedom in case of emergency. The design of the vehicle addresses propulsion, orbital operations, reentry, landing and recovery, power and communication, and life support. In light of recent modifications in Space Station design, Project EGRESS (Earthbound Guaranteed ReEntry from Space Station) pays particular attention to its impact on Space Station operations, interfaces and docking facilities, and maintenance needs. A water landing, medium lift vehicle was found to best satisfy project goals of simplicity and cost efficiency without sacrificing the safety and reliability requirements. With a single vehicle, one injured crew member could be returned to Earth with minimal pilot involvement. Since the craft is capable of returning up to five crew members, two such permanently docked vehicles would allow full evacuation of the Space Station. The craft could be constructed entirely with available 1990 technology and launched aboard a shuttle orbiter.

  18. KSC-2009-5541

    NASA Image and Video Library

    2009-10-20

    CAPE CANAVERAL, Fla. - Inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida, the 327-foot-tall Ares I-X rocket stands on its mobile launcher platform. The transfer of the pad from the Space Shuttle Program to the Constellation Program took place May 31. Modifications made to the pad include the removal of shuttle unique subsystems, such as the orbiter access arm and a section of the gaseous oxygen vent arm, along with the installation of three 600-foot lightning towers, access platforms, environmental control systems and a vehicle stabilization system. Part of the Constellation Program, the Ares I-X is the test vehicle for the Ares I. The Ares I-X flight test is targeted for Oct. 27. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo credit: NASA/Kim Shiflett

  19. Cassini Spacecraft In-Flight Swap to Backup Attitude Control Thrusters

    NASA Technical Reports Server (NTRS)

    Bates, David M.

    2010-01-01

    NASA's Cassini Spacecraft, launched on October 15th, 1997 and arrived at Saturn on June 30th, 2004, is the largest and most ambitious interplanetary spacecraft in history. In order to meet the challenging attitude control and navigation requirements of the orbit profile at Saturn, Cassini is equipped with a monopropellant thruster based Reaction Control System (RCS), a bipropellant Main Engine Assembly (MEA) and a Reaction Wheel Assembly (RWA). In 2008, after 11 years of reliable service, several RCS thrusters began to show signs of end of life degradation, which led the operations team to successfully perform the swap to the backup RCS system, the details and challenges of which are described in this paper. With some modifications, it is hoped that similar techniques and design strategies could be used to benefit other spacecraft.

  20. Modification of earth-satellite orbits using medium-energy pulsed lasers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Phipps, C.R.

    1992-01-01

    Laser Impulse Space Propulsion (LISP) has become an attractive concept, due to recent advances in gas laser technology, high-speed segmented mirrors and improved coeffici-ents for momentum coupling to targets in pulsed laser ablation. There are numerous specialized applications of the basic concept to space science-ranging from far-future and high capital cost to the immediate and inexpensive, such as: LEO-LISP (launch of massive objects into low-Earth-Orbit at dramatically improved cost-per-kg relative to present practice); LEGO-LISP (LEO to geosynchronous transfers); LO-LISP) (periodic re-boost of decaying LEO orbits); and LISK (geosynchronous satellite station-keeping). It is unlikely that one type of laser will bemore » best for all scenarios. In this paper, we will focus on the last two applications.« less

  1. Modification of earth-satellite orbits using medium-energy pulsed lasers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Phipps, C.R.

    1992-10-01

    Laser Impulse Space Propulsion (LISP) has become an attractive concept, due to recent advances in gas laser technology, high-speed segmented mirrors and improved coeffici-ents for momentum coupling to targets in pulsed laser ablation. There are numerous specialized applications of the basic concept to space science-ranging from far-future and high capital cost to the immediate and inexpensive, such as: LEO-LISP (launch of massive objects into low-Earth-Orbit at dramatically improved cost-per-kg relative to present practice); LEGO-LISP (LEO to geosynchronous transfers); LO-LISP) (periodic re-boost of decaying LEO orbits); and LISK (geosynchronous satellite station-keeping). It is unlikely that one type of laser will bemore » best for all scenarios. In this paper, we will focus on the last two applications.« less

  2. A Simple Relativistic Bohr Atom

    ERIC Educational Resources Information Center

    Terzis, Andreas F.

    2008-01-01

    A simple concise relativistic modification of the standard Bohr model for hydrogen-like atoms with circular orbits is presented. As the derivation requires basic knowledge of classical and relativistic mechanics, it can be taught in standard courses in modern physics and introductory quantum mechanics. In addition, it can be shown in a class that…

  3. Visualizing redox orbitals and their potentials in advanced lithium-ion battery materials using high-resolution x-ray Compton scattering

    PubMed Central

    Hafiz, Hasnain; Suzuki, Kosuke; Barbiellini, Bernardo; Orikasa, Yuki; Callewaert, Vincent; Kaprzyk, Staszek; Itou, Masayoshi; Yamamoto, Kentaro; Yamada, Ryota; Uchimoto, Yoshiharu; Sakurai, Yoshiharu; Sakurai, Hiroshi; Bansil, Arun

    2017-01-01

    Reduction-oxidation (redox) reactions are the key processes that underlie the batteries powering smartphones, laptops, and electric cars. A redox process involves transfer of electrons between two species. For example, in a lithium-ion battery, current is generated when conduction electrons from the lithium anode are transferred to the redox orbitals of the cathode material. The ability to visualize or image the redox orbitals and how these orbitals evolve under lithiation and delithiation processes is thus of great fundamental and practical interest for understanding the workings of battery materials. We show that inelastic scattering spectroscopy using high-energy x-ray photons (Compton scattering) can yield faithful momentum space images of the redox orbitals by considering lithium iron phosphate (LiFePO4 or LFP) as an exemplar cathode battery material. Our analysis reveals a new link between voltage and the localization of transition metal 3d orbitals and provides insight into the puzzling mechanism of potential shift and how it is connected to the modification of the bond between the transition metal and oxygen atoms. Our study thus opens a novel spectroscopic pathway for improving the performance of battery materials. PMID:28845452

  4. Visualizing redox orbitals and their potentials in advanced lithium-ion battery materials using high-resolution x-ray Compton scattering.

    PubMed

    Hafiz, Hasnain; Suzuki, Kosuke; Barbiellini, Bernardo; Orikasa, Yuki; Callewaert, Vincent; Kaprzyk, Staszek; Itou, Masayoshi; Yamamoto, Kentaro; Yamada, Ryota; Uchimoto, Yoshiharu; Sakurai, Yoshiharu; Sakurai, Hiroshi; Bansil, Arun

    2017-08-01

    Reduction-oxidation (redox) reactions are the key processes that underlie the batteries powering smartphones, laptops, and electric cars. A redox process involves transfer of electrons between two species. For example, in a lithium-ion battery, current is generated when conduction electrons from the lithium anode are transferred to the redox orbitals of the cathode material. The ability to visualize or image the redox orbitals and how these orbitals evolve under lithiation and delithiation processes is thus of great fundamental and practical interest for understanding the workings of battery materials. We show that inelastic scattering spectroscopy using high-energy x-ray photons (Compton scattering) can yield faithful momentum space images of the redox orbitals by considering lithium iron phosphate (LiFePO 4 or LFP) as an exemplar cathode battery material. Our analysis reveals a new link between voltage and the localization of transition metal 3d orbitals and provides insight into the puzzling mechanism of potential shift and how it is connected to the modification of the bond between the transition metal and oxygen atoms. Our study thus opens a novel spectroscopic pathway for improving the performance of battery materials.

  5. Ordered defects in Fe1-xS generate additional magnetic anisotropy symmetries

    NASA Astrophysics Data System (ADS)

    Koulialias, D.; Charilaou, M.; Schäublin, R.; Mensing, C.; Weidler, P. G.; Löffler, J. F.; Gehring, A. U.

    2018-01-01

    Non-stoichiometric monoclinic 4C pyrrhotite (Fe7S8), a ferrimagnetic monosulfide that has been intensively used as a remanence carrier to infer the magnetization of the Earth's crust and extraterrestrial materials, exhibits a characteristic low-temperature transition accompanied by complex modifications in anisotropy and magnetization. We demonstrate that the magnetic rotational symmetry of the 4C pyrrhotite is critically affected by the order of the defective Fe-sites, and this in turn is a key to decipher the physics behind the low-temperature transition. Our torque experiments and numerical simulations show an emergent four-fold rotational symmetry in the c-plane of the 4C pyrrhotite at T < 30 K. This symmetry breaking associated with the transition is caused by the competitive interaction of two inherently hexagonal systems generated by two groups of Fe-sites with different local anisotropy fields that stem from the vacancy arrangement in the 4C stacking sequence, and it is triggered by changes in the spin orbit coupling due to the overlap of Fe-Fe electron orbitals at low-temperature. This mechanism provides a new explanation for the magnetic transition in 4C pyrrhotite at low temperature and could also cast light on non-trivial magnetic phenomena in defective systems.

  6. Results of Two-Stage Light-Gas Gun Development Efforts and Hypervelocity Impact Tests of Advanced Thermal Protection Materials

    NASA Technical Reports Server (NTRS)

    Cornelison, C. J.; Watts, Eric T.

    1998-01-01

    Gun development efforts to increase the launching capabilities of the NASA Ames 0.5-inch two-stage light-gas gun have been investigated. A gun performance simulation code was used to guide initial parametric variations and hardware modifications, in order to increase the projectile impact velocity capability to 8 km/s, while maintaining acceptable levels of gun barrel erosion and gun component stresses. Concurrent with this facility development effort, a hypervelocity impact testing series in support of the X-33/RLV program was performed in collaboration with Rockwell International. Specifically, advanced thermal protection system materials were impacted with aluminum spheres to simulate impacts with on-orbit space debris. Materials tested included AETB-8, AETB-12, AETB-20, and SIRCA-25 tiles, tailorable advanced blanket insulation (TABI), and high temperature AFRSI (HTA). The ballistic limit for several Thermal Protection System (TPS) configurations was investigated to determine particle sizes which cause threshold TPS/structure penetration. Crater depth in tiles was measured as a function of impact particle size. The relationship between coating type and crater morphology was also explored. Data obtained during this test series was used to perform a preliminary analysis of the risks to a typical orbital vehicle from the meteoroid and space debris environment.

  7. KSC-95PC585

    NASA Image and Video Library

    1995-04-17

    KENNEDY SPACE CENTER, FLA. - A Space Shuttle Main Engine (SSME) hoist prepares to lift the first Block 1 engine to be installed in an orbiter into the number one position on Discovery while the spaceplane is being prepared for the STS-70 mission in the high bay of Orbiter Processing Facility 2. The new engine, SSME No. 2036, features a new high-pressure liquid oxygen turbopump, a two-duct powerhead, a baffleless main injector, a single-coil heat exchanger and start sequence modifications. The other two main engines to be used during the liftoff of the STS-70 mission are of the existing Phase II design.

  8. 47 CFR 25.164 - Milestones.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Milestones. (a) Licensees of geostationary orbit satellite systems other than DBS and DARS satellite systems...) Licensees of non-geostationary orbit satellite systems other than DBS and DARS satellite systems licensed on... placed in the authorized orbital location or non-geostationary orbit(s) and that in-orbit operation of...

  9. Investigation of failure to separate an Inconel 718 frangible nut

    NASA Technical Reports Server (NTRS)

    Hoffman, William C., III; Hohmann, Carl

    1994-01-01

    The 2.5-inch frangible nut is used in two places to attach the Space Shuttle Orbiter to the External Tank. It must be capable of sustaining structural loads and must also separate into two pieces upon command. Structural load capability is verified by proof loading each flight nut, while ability to separate is verified on a sample of a production lot. Production lots of frangible nuts beginning in 1987 experienced an inability to reliably separate using one of two redundant explosive boosters. The problems were identified in lot acceptance tests, and the cause of failure has been attributed to differences in the response of the Inconel 718. Subsequent tests performed on the frangible nuts resulted in design modifications to the nuts along with redesign of the explosive booster to reliably separate the frangible nut. The problem history along with the design modifications to both the explosive booster and frangible nut are discussed in this paper. Implications of this failure experience impact any pyrotechnic separation system involving fracture of materials with respect to design margin control and lot acceptance testing.

  10. JPSS Cryosphere Algorithms: Integration and Testing in Algorithm Development Library (ADL)

    NASA Astrophysics Data System (ADS)

    Tsidulko, M.; Mahoney, R. L.; Meade, P.; Baldwin, D.; Tschudi, M. A.; Das, B.; Mikles, V. J.; Chen, W.; Tang, Y.; Sprietzer, K.; Zhao, Y.; Wolf, W.; Key, J.

    2014-12-01

    JPSS is a next generation satellite system that is planned to be launched in 2017. The satellites will carry a suite of sensors that are already on board the Suomi National Polar-orbiting Partnership (S-NPP) satellite. The NOAA/NESDIS/STAR Algorithm Integration Team (AIT) works within the Algorithm Development Library (ADL) framework which mimics the operational JPSS Interface Data Processing Segment (IDPS). The AIT contributes in development, integration and testing of scientific algorithms employed in the IDPS. This presentation discusses cryosphere related activities performed in ADL. The addition of a new ancillary data set - NOAA Global Multisensor Automated Snow/Ice data (GMASI) - with ADL code modifications is described. Preliminary GMASI impact on the gridded Snow/Ice product is estimated. Several modifications to the Ice Age algorithm that demonstrates mis-classification of ice type for certain areas/time periods are tested in the ADL. Sensitivity runs for day time, night time and terminator zone are performed and presented. Comparisons between the original and modified versions of the Ice Age algorithm are also presented.

  11. Focused-ion-beam induced interfacial intermixing of magnetic bilayers for nanoscale control of magnetic properties.

    PubMed

    Burn, D M; Hase, T P A; Atkinson, D

    2014-06-11

    Modification of the magnetic properties in a thin-film ferromagnetic/non-magnetic bilayer system by low-dose focused ion-beam (FIB) induced intermixing is demonstrated. The highly localized capability of FIB may be used to locally control magnetic behaviour at the nanoscale. The magnetic, electronic and structural properties of NiFe/Au bilayers were investigated as a function of the interfacial structure that was actively modified using focused Ga(+) ion irradiation. Experimental work used MOKE, SQUID, XMCD as well as magnetoresistance measurements to determine the magnetic behavior and grazing incidence x-ray reflectivity to elucidate the interfacial structure. Interfacial intermixing, induced by low-dose irradiation, is shown to lead to complex changes in the magnetic behavior that are associated with monotonic structural evolution of the interface. This behavior may be explained by changes in the local atomic environment within the interface region resulting in a combination of processes including the loss of moment on Ni and Fe, an induced moment on Au and modifications to the spin-orbit coupling between Au and NiFe.

  12. Evidence for a Trapped Radical (OH) on Ariel, Oberon, and Titania from Hubble Space Telescope Ultraviolet Spectra

    NASA Technical Reports Server (NTRS)

    Roush, Ted L.; Noll, Keith S.; Pendleton, Yvonne J.; DeVincenzi, Donald (Technical Monitor)

    2000-01-01

    The moons Ariel, Titania, and Oberon have orbits lying within the magnetosphere of Uranus, exposing them to particle irradiation from trapped Ions. This Is similar to the situation experienced by the jovian moons Europa, Ganymede, and Callisto, as well as the saturnian satellites Enceladus, Tethys, Dione, and Rhea. Identification of SO2 on Europa, Ganymede and Callisto, and O3 on Ganymede, Rhea, and Dione has supported suggestions that chemical modifications occur on icy bodies due to ion bombardment associated with the particles entrained within the magnetospheric fields of Jupiter and Saturn. Similar to the Jovian and saturnian satellites mentioned above, water ice is a major component on the larger uranian satellites", thus one might anticipate chemical modification to he an important process in the uranian system. Laboratory studies or the interaction of ultraviolet (uv) and charged-particle radiation with water ice show that in addition to molecular species, a variety of radicals are also produced. We report here evidence for an uv absorption feature in the spectra of Ariel, Titania, and Oberon that we identify as due, in part, to OH; providing the first evidence of a radical produced and trapped on an icy moon within our solar system.

  13. High Speed, Low Cost Telemetry Access from Space Development Update on Programmable Ultra Lightweight System Adaptable Radio (PULSAR)

    NASA Technical Reports Server (NTRS)

    Simms, William Herbert, III; Varnavas, Kosta; Eberly, Eric

    2014-01-01

    Software Defined Radio (SDR) technology has been proven in the commercial sector since the early 1990's. Today's rapid advancement in mobile telephone reliability and power management capabilities exemplifies the effectiveness of the SDR technology for the modern communications market. In contrast, the foundations of transponder technology presently qualified for satellite applications were developed during the early space program of the 1960's. Conventional transponders are built to a specific platform and must be redesigned for every new bus while the SDR is adaptive in nature and can fit numerous applications with no hardware modifications. A SDR uses a minimum amount of analog / Radio Frequency (RF) components to up/down-convert the RF signal to/from a digital format. Once the signal is digitized, all processing is performed using hardware or software logic. Typical SDR digital processes include; filtering, modulation, up/down converting and demodulation. NASA Marshall Space Flight Center (MSFC) Programmable Ultra Lightweight System Adaptable Radio (PULSAR) leverages existing MSFC SDR designs and commercial sector enhanced capabilities to provide a path to a radiation tolerant SDR transponder. These innovations (1) reduce the cost of NASA Low Earth Orbit (LEO) and Deep Space standard transponders, (2) decrease power requirements, and (3) commensurately reduce volume. A second pay-off is the increased SDR flexibility by allowing the same hardware to implement multiple transponder types simply by altering hardware logic - no change of hardware is required - all of which will ultimately be accomplished in orbit. Development of SDR technology for space applications will provide a highly capable, low cost transponder to programs of all sizes. The MSFC PULSAR Project results in a Technology Readiness Level (TRL) 7 low-cost telemetry system available to Smallsat and CubeSat missions, as well as other platforms. This paper documents the continued development and verification/validation of the MSFC SDR, called PULSAR, which contributes to advancing the state-of-the-art in transponder design - directly applicable to the SmallSat and CubeSat communities. This paper focuses on lessons learned on the first sub-orbital flight (high altitude balloon) and the follow-on steps taken to validate PULSAR. A sounding rocket launch, currently planned for 03/2015, will further expose PULSAR to the high dynamics of sub-orbital flights. Future opportunities for orbiting satellite incorporation reside in the small satellite missions (FASTSat, CubeSat. etc.).

  14. Global-scale Observations of the Limb and Disk (GOLD) Mission -Ultraviolet Remote Sensing of Earth's Space Environment from Geostationary Orbit

    NASA Astrophysics Data System (ADS)

    Burns, A. G.; Eastes, R.

    2017-12-01

    The GOLD mission of opportunity will fly a far ultraviolet imaging spectrograph in geostationary (GEO) orbit as a hosted payload. The mission is scheduled for launch in late January 2018 on SES-14, a commercial communications satellite that will be stationed over eastern South America at 47.5 degrees west longitude. GOLD is on schedule to be the first NASA science mission to fly as a hosted payload on a commercial communications satellite. The GOLD imager has two identical channels. Each channel can scan the full disk at a 30 minute cadence, making spectral images of Earth's UV emission from 132 to 162 nm, as well as make a measurement on the Earth's limb. Remote sensing techniques that have been proven on previous Low Earth Orbit (LEO) missions will be used to derive fundamental parameters for the neutral and ionized space environment. Parameters that will be derived include composition (O/N2 ratio) and temperature of the neutral atmosphere on the dayside disk. On the nightside, peak electron densities will be obtained in the low latitude ionosphere. Many of the algorithms developed for the mission are extensions of ones used on previous earth and planetary missions, with modifications for observations from geostationary orbit. All the algorithms have been tested using simulated observations based on the actual instrument performance. From geostationary orbit, GOLD can repeatedly image the same geographic locations over most of the hemisphere at a cadence comparable to that of the T-I system (order of an hour). Such time resolution and spatial coverage will allow the mission to track the changes due to geomagnetic storms, variations in solar extreme ultraviolet radiation, and forcing from the lower atmosphere. In addition to providing a new perspective by being able to repeatedly remotely sense the same hemisphere at a high cadence, GOLD's simultaneous measurements of not only composition but also temperatures across the disk will provide a valuable, new parameter for understanding of how the T-I system responds to forcing from both the sun and the lower atmosphere.

  15. Rapid near-optimal trajectory generation and guidance law development for single-stage-to-orbit airbreathing vehicles

    NASA Technical Reports Server (NTRS)

    Calise, A. J.; Flandro, G. A.; Corban, J. E.

    1990-01-01

    General problems associated with on-board trajectory optimization, propulsion system cycle selection, and with the synthesis of guidance laws were addressed for an ascent to low-earth-orbit of an air-breathing single-stage-to-orbit vehicle. The NASA Generic Hypersonic Aerodynamic Model Example and the Langley Accelerator aerodynamic sets were acquired and implemented. Work related to the development of purely analytic aerodynamic models was also performed at a low level. A generic model of a multi-mode propulsion system was developed that includes turbojet, ramjet, scramjet, and rocket engine cycles. Provisions were made in the dynamic model for a component of thrust normal to the flight path. Computational results, which characterize the nonlinear sensitivity of scramjet performance to changes in vehicle angle of attack, were obtained and incorporated into the engine model. Additional trajectory constraints were introduced: maximum dynamic pressure; maximum aerodynamic heating rate per unit area; angle of attack and lift limits; and limits on acceleration both along and normal to the flight path. The remainder of the effort focused on required modifications to a previously derived algorithm when the model complexity cited above was added. In particular, analytic switching conditions were derived which, under appropriate assumptions, govern optimal transition from one propulsion mode to another for two cases: the case in which engine cycle operations can overlap, and the case in which engine cycle operations are mutually exclusive. The resulting guidance algorithm was implemented in software and exercised extensively. It was found that the approximations associated with the assumed time scale separation employed in this work are reasonable except over the Mach range from roughly 5 to 8. This phenomenon is due to the very large thrust capability of scramjets in this Mach regime when sized to meet the requirement for ascent to orbit. By accounting for flight path angle and flight path angle rate in construction of the flight path over this Mach range, the resulting algorithm provides the means for rapid near-optimal trajectory generation and propulsion cycle selection over the entire Mach range from take-off to orbit.

  16. Study of an orbiting tethered dumbbell system having positive orbital energy

    NASA Technical Reports Server (NTRS)

    Arnold, David A.

    1988-01-01

    For very long tethered systems the sum of the kinetic and potential energy can be positive. The system remains in a circular orbit as long as the masses remain vertically aligned. The system is unstable without constant control of the alignment. If the upper mass rotates forward in the direction of the orbital motion, the system escapes out of orbit. If the upper mass rotates backward, the system falls out of orbit and the lower mass impacts the body around which the system is orbiting.

  17. Opportunities investigating the thermosphere/ionosphere system by low Earth orbiting satellite missions (Invited)

    NASA Astrophysics Data System (ADS)

    Stolle, C.; Park, J.; Luhr, H.

    2013-12-01

    New opportunities for investigating the thermosphere/ionosphere interactions arise from in situ measurements on board low Earth orbiting satellites. Ten years of successful operation of the CHAMP satellite mission at a unique orbit altitude of about 400 km revealed many interesting features of the coupling between the thermosphere and ionosphere and the different atmospheric layers. Examples are the investigations of signatures of stratospheric warming events that are known to change significantly the dynamics of the equatorial ionosphere. It was shown that these modifications are due to an enhancement of lunar tidal effects, e.g. reflected in the thermospheric zonal wind, in the equatorial electroje or in the eastward electric field. Another topic concerns the energy deposit in the F-region though cooling of the thermal electron gas caused by elastic and inelastic processes (Schunk and Nagy, 2009). We find that a significant deposition is present during day at mid latitudes. At low latitudes the energy flux remain important until midnight. Observed heating rates depend on the satellite altitudes, but they are globally available from the CHAMP data. Further enhanced investigations are expected from ESA's three-satellite Swarm mission with a launch planned in 2014. The mission will provide observations of electron density, electron and ion temperature, ion drift and the electric field together with neutral density and winds. High-precision magnetic field observations will allow monitoring ionospheric currents.

  18. Orbital Modification of the Himalia Family during an Early Solar System Dynamical Instability

    NASA Astrophysics Data System (ADS)

    Li, Daohai; Christou, Apostolos A.

    2017-11-01

    Among the irregular satellites orbiting Jupiter, the Himalia family is characterized by a high velocity dispersion δ v of several hundred {{m}} {{{s}}}-1 among its members, inconsistent with a collisional origin. Efforts to account for this through internecine gravitational interactions do not readily reproduce this feature. Here, we revisit the problem in the context of recent cosmogonical models, where the giant planets migrated significantly through interaction with a planetesimal disk and suffered encounters with planetesimals and planet-sized objects. Our starting assumption is that family formation either predated this phase or occurred soon after its onset. We simulate numerically the diffusive effect of three distinct populations of perturbers on a set of test particles representing the family: Moon-sized (MPT) and Pluto-sized (PPT) planetesimals, and planetary-mass objects (PMO) with masses typical of ice-giant planets. We find that PPT flybys are inefficient, but encounters with MPTs raise the δ v of ∼60% of our test particles to > 200 {{m}} {{{s}}}-1 with respect to Himalia, in agreement with observations. As MPTs may not have been abundant in the disk, we simulate encounters between Jupiter and PMOs. We find that too few encounters generate less dispersion than MPTs while too many essentially destroy the family. For PMO masses in the range 5{--}20 {m}\\oplus , the family orbital distribution is reproduced by a few tens of encounters.

  19. Autonomous Formation Flying from Ground to Flight

    NASA Technical Reports Server (NTRS)

    Chapman, Keith B.; Dell, Gregory T.; Rosenberg, Duane L.; Bristow, John

    1999-01-01

    The cost of on-orbit operations remains a significant and increasingly visible concern in the support of satellite missions. Headway has been made in automating some ground operations; however, increased mission complexity and more precise orbital constraints have compelled continuing human involvement in mission design and maneuver planning operations. AI Solutions, Inc. in cooperation with the National Aeronautics and Space Administration's (NASA) Goddard Space Flight Center (GSFC) has tackled these more complex problems through the development of AutoCon as a tool for an automated solution. NASA is using AutoCon to automate the maneuver planning for the Earth Orbiter-1 (EO-1) mission. AutoCon was developed originally as a ground system tool. The EO-1 mission will be using a scaled version of AutoCon on-board the EO-1 satellite to command orbit adjustment maneuvers. The flight version of AutoCon plans maneuvers based on formation flying algorithms developed by GSFC, JPL, and other industry partners. In its fully autonomous mode, an AutoCon planned maneuver will be executed on-board the satellite without intervention from the ground. This paper describes how AutoCon automates maneuver planning for the formation flying constraints of the EO-1 mission. AutoCon was modified in a number of ways to automate the maneuver planning on-board the satellite. This paper describes how the interface and functionality of AutoCon were modified to support the on-board system. A significant component of this modification was the implementation of a data smoother, based on a Kalman filter, that ensures that the spacecraft states estimated by an on-board GPS receiver are as accurate as possible for maneuver planning. This paper also presents the methodology use to scale the AutoCon functionality to fit and execute on the flight hardware. This paper also presents the modes built that allow the incremental phasing in of autonomy. New technologies for autonomous operations are usually received with significant, and probably appropriate trepidation. A number of safeguards have been designed in both AutoCon and the interfacing systems to alleviate the potential of mission-impacting anomalies from the on-board autonomous system. This paper describes the error checking, input data integrity validation and limits set on maneuvers in AutoCon and the on-board system.

  20. Covalent intermolecular interaction of the nitric oxide dimer (NO)2

    NASA Astrophysics Data System (ADS)

    Zhang, Hui; Zheng, Gui-Li; Lv, Gang; Geng, Yi-Zhao; Ji, Qing

    2015-09-01

    Covalent bonds arise from the overlap of the electronic clouds in the internucleus region, which is a pure quantum effect and cannot be obtained in any classical way. If the intermolecular interaction is of covalent character, the result from direct applications of classical simulation methods to the molecular system would be questionable. Here, we analyze the special intermolecular interaction between two NO molecules based on quantum chemical calculation. This weak intermolecular interaction, which is of covalent character, is responsible for the formation of the NO dimer, (NO)2, in its most stable conformation, a cis conformation. The natural bond orbital (NBO) analysis gives an intuitive illustration of the formation of the dimer bonding and antibonding orbitals concomitant with the breaking of the π bonds with bond order 0.5 of the monomers. The dimer bonding is counteracted by partially filling the antibonding dimer orbital and the repulsion between those fully or nearly fully occupied nonbonding dimer orbitals that make the dimer binding rather weak. The direct molecular mechanics (MM) calculation with the UFF force fields predicts a trans conformation as the most stable state, which contradicts the result of quantum mechanics (QM). The lesson from the investigation of this special system is that for the case where intermolecular interaction is of covalent character, a specific modification of the force fields of the molecular simulation method is necessary. Project supported by the National Natural Science Foundation of China (Grant Nos. 90403007 and 10975044), the Key Subject Construction Project of Hebei Provincial Universities, China, the Research Project of Hebei Education Department, China (Grant Nos. Z2012067 and Z2011133), the National Natural Science Foundation of China (Grant No. 11147103), and the Open Project Program of State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, China (Grant No. Y5KF211CJ1).

  1. New concepts in ionospheric modification. Final report, 15 April 1986-30 September 1987

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Banks, P.M.; Fraser-Smith, A.C.; Gilchrist, B.E.

    1987-04-01

    This report considers the ionospheric modification that can be produced by energetic charged-particle and photon beams, which are emitted from a platform or vehicle (spacecraft or rockets) located in the ionosphere. The various beams considered include (1) charged-particle beams composed of low-, moderate-, and high-energy electrons, (2) beams of ions and plasma, and (3) photon beams of soft x rays and extreme-ultraviolet radiation. Briefly considered, in addition to the beam topics, is the ionospheric modification produced by the release of neutral gas of high molecular weight from a rapidly moving vehicle such as the Space Shuttle Orbiter. When a rankingmore » is made in terms of the new information that may be obtained, the scale of the modification that may be produced, and the availability of beam sources, ionospheric modification by means of relativistic electron beams appears particularly promising. However, all the methods have their own distinctive features that could make their use desirable under particular circumstances. The modification produced by means of beams of soft x rays, for example, is not strongly dependent on the beam's direction relative to the earth's magnetic field, and thus modification can be produced in regions inaccessible to a charged-particle beam from the same vehicle.« less

  2. Orbital Atherectomy for Treating De Novo Severely Calcified Coronary Narrowing (1-Year Results from the Pivotal ORBIT II Trial).

    PubMed

    Généreux, Philippe; Lee, Arthur C; Kim, Christopher Y; Lee, Michael; Shlofmitz, Richard; Moses, Jeffrey W; Stone, Gregg W; Chambers, Jeff W

    2015-06-15

    Percutaneous coronary intervention of severely calcified lesions has historically been associated with major adverse cardiac event (MACE) rates as high as 30%. In the ORBIT II (Evaluate the Safety and Efficacy of OAS in Treating Severely Calcified Coronary Lesions) trial, treatment of de novo severely calcified lesions with the Diamondback 360° Coronary Orbital Atherectomy System (OAS) resulted in low rates of procedural and 30-day adverse ischemic events. The long-term results from this trial have not been reported. We sought to determine the 1-year outcomes after orbital atherectomy of severely calcified coronary lesions. ORBIT II was a single-arm trial enrolling 443 subjects at 49 US sites with severely calcified lesions usually excluded from randomized trials. OAS utilizes a centrifugal differential sanding mechanism of action for plaque modification prior to stent implantation. After OAS drug-eluting stents were implanted in 88.2% of the patients. The primary safety end point was 30-day MACE, the composite of cardiac death, myocardial infarction, or target vessel revascularization [TVR]. The present analysis reports the 1-year follow-up results from ORBIT II. One-year data were available in 433 of 443 patients (97.7%), with median follow-up time of 16.7 months. The 1-year MACE rate was 16.4%, including cardiac death (3.0%), myocardial infarction (9.7%), and target vessel revascularization (5.9%). The 1-year target lesion revascularization rate was 4.7%, and stent thrombosis occurred in 1 patient (0.2%). Independent predictors of 1-year MACE and target vessel revascularization were diameter stenosis at baseline and the use of bare-metal stents. In patients with severely calcified lesions who underwent percutaneous coronary intervention, the use of OAS was associated with low rates of 1-year adverse ischemic events compared with historical controls. This finding has important clinical implications for the selection of optimum treatment strategies for patients with severely calcified lesions. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Electron-phonon coupling and superconductivity in the (4/3)-monolayer of Pb on Si(111): Role of spin-orbit interaction

    NASA Astrophysics Data System (ADS)

    Sklyadneva, I. Yu.; Heid, R.; Bohnen, K.-P.; Echenique, P. M.; Chulkov, E. V.

    2018-05-01

    The effect of spin-orbit coupling on the electron-phonon interaction in a (4/3)-monolayer of Pb on Si(111) is investigated within the density-functional theory and linear-response approach in the mixed-basis pseudopotential representation. We show that the spin-orbit interaction produces a large weakening of the electron-phonon coupling strength, which appears to be strongly overestimated in the scalar relativistic calculations. The effect of spin-orbit interaction is largely determined by the induced modification of Pb electronic bands and a stiffening of the low-energy part of phonon spectrum, which favor a weakening of the electron-phonon coupling strength. The state-dependent strength of the electron-phonon interaction in occupied Pb electronic bands varies depending on binding energy rather than electronic momentum. It is markedly larger than the value averaged over electron momentum because substrate electronic bands make a small contribution to the phonon-mediated scattering and agrees well with the experimental data.

  4. Compositional variation in the Hadley Apennine region

    NASA Technical Reports Server (NTRS)

    Clark, P. E.; Hawke, B. R.

    1982-01-01

    Orbital geochemical data in the Hadley Apennine region are related to typical rock compositions and used in determining the distribution of soils derived from the rock types found in this region. Orbital XRF Mg/Si and Al/Si intensities are the orbital data that are used primarily. These data are corrected for spurious interorbit variation using a modification of a previously developed method. The corrected values are than converted to % MgO and % Al2O3, respectively, from theoretical considerations, and as such are compared with similar concentrations for typical lunar rocks and soils of the Apollo 15 landing site. The relationship of the XRF values to Fe, Ti, and Th concentrations, derived from gamma-ray observations, is also considered. It is established that the orbital geochemistry data for this region are consistent with the presence of a mixture of ANT suite and Fra Mauro basalt components frequently dominated by a KREEP basalt component toward the west and by a mafic pyroclastic component toward the east.

  5. Development of dedicated target tracking capability for the CERES instruments through flight software: enhancing radiometric validation and on-orbit calibration

    NASA Astrophysics Data System (ADS)

    Teague, Kelly K.; Smith, G. Louis; Priestley, Kory; Lukashin, Constantine; Roithmayr, Carlos

    2012-09-01

    Five CERES scanning radiometers have been flown to date. The Proto-Flight Model flew aboard the Tropical Rainfall Measurement Mission spacecraft in November 1997. Two CERES instruments, Flight Models (FM) 1 and 2, are aboard the Terra spacecraft, which was launched in December 1999. Two more CERES instruments, FM-3 and FM-4, are on the Aqua spacecraft, which was placed in orbit in May 2002. These instruments continue to operate after providing over a decade of Earth Radiation Budget data. The CERES FM-5 instrument, onboard the Suomi-NPP spacecraft, launched in October 2011. The CERES FM- 6 instrument is manifested on the JPPS-1 spacecraft to be launched in December 2016. A successor to these instruments is presently in the definition stage. This paper describes the evolving role of flight software in the operation of these instruments to meet the Science objectives of the mission and also the ability to execute supplemental tasks as they evolve. In order to obtain and maintain high accuracy in the data products from these instruments, a number of operational activities have been developed and implemented since the instruments were originally designed and placed in orbit. These new activities are possible because of the ability to exploit and modify the flight software, which operates the instruments. The CERES Flight Software interface was designed to allow for on-orbit modification, and as such, constantly evolves to meet changing needs. The purpose of this paper is to provide a brief overview of modifications which have been developed to allow dedicated targeting of specific geographic locations as the CERES sensor flies overhead on its host spacecraft. This new observing strategy greatly increases the temporal and angular sampling for specific targets of high scientific interest.

  6. Technical Modifications for Intraoral Quadrangular Le Fort II Osteotomy.

    PubMed

    Klug, Clemens; Cede, Julia

    2017-02-01

    The intraoral quadrangular Le Fort II osteotomy (IQLFIIO) represents a reliable surgical method in cases of midfacial deficiency with good functional, esthetic, and stable long-term results. In this technical note, we present 3 surgical modifications to previous reports: 1) inferior orbital rim osteotomy by angulated piezosurgical instruments, thereby avoiding the use of chisels in the orbital region; 2) osteosynthetic fixation only laterally at the zygomatic buttress with 2 L-shaped miniplates, thus avoiding paranasal osteosynthesis; and 3) advancement step camouflage in the lateral infraorbital region with a compound mass of autologous bone chips and fibrin glue with the intention to reduce bone block-associated side effects. Thirteen consecutive patients presenting with midfacial deficiency and Class III malocclusion were treated by IQLFIIO and mandibular osteotomy. In all cases, osteotomy and consecutive down fracture could be conducted as planned using the piezotome. No atypical fractures were encountered. No cases of infraorbital nerve anesthesia developed. Midfacial hypesthesia was found in 54% of the operated sides after 3 months, in 23% after 6 months, and in 13% after 12 months. The 5-month postoperative 3-dimensional scans revealed osseous healing at the infraorbital advancement step. Our results suggest that IQLFIIO can be conducted fully without chisels in the orbital region. Implementation of piezosurgery in IQLFIIO allows for safe bone cutting in the orbital region. Two miniplates and step camouflage with fibrin glue-stabilized bone chips were sufficient for osseous healing. Future studies will focus on quantitative soft to hard tissue changes that occur with IQLFIIO advancement. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  7. Changes of Space Debris Orbits After LDR Operation

    NASA Astrophysics Data System (ADS)

    Wnuk, E.; Golebiewska, J.; Jacquelard, C.; Haag, H.

    2013-09-01

    A lot of technical studies are currently developing concepts of active removal of space debris to protect space assets from on orbit collision. For small objects, such concepts include the use of ground-based lasers to remove or reduce the momentum of the objects thereby lowering their orbit in order to facilitate their decay by re-entry into the Earth's atmosphere. The concept of the Laser Debris Removal (LDR) system is the main subject of the CLEANSPACE project. One of the CLEANSPACE objectives is to define a global architecture (including surveillance, identification and tracking) for an innovative ground-based laser solution, which can remove hazardous medium debris around selected space assets. The CLEANSPACE project is realized by a European consortium in the frame of the European Commission Seventh Framework Programme (FP7), Space topic. The use of sequence of laser operations to remove space debris, needs very precise predictions of future space debris orbital positions, on a level even better than 1 meter. Orbit determination, tracking (radar, optical and laser) and orbit prediction have to be performed with accuracy much better than so far. For that, the applied prediction tools have to take into account all perturbation factors that influence object orbit. The expected object's trajectory after the LDR operation is a lowering of its perigee. To prevent the debris with this new trajectory to collide with another object, a precise trajectory prediction after the LDR sequence is therefore the main task allowing also to estimate re-entry parameters. The LDR laser pulses change the debris object velocity v. The future orbit and re-entry parameters of the space debris after the LDR engagement can be calculated if the resulting ?v vector is known with the sufficient accuracy. The value of the ?v may be estimated from the parameters of the LDR station and from the characteristics of the orbital debris. However, usually due to the poor knowledge of the debris object's size, mass, spin and chemical composition the value and the direction of the vector ?v cannot be estimated with the high accuracy. Therefore, a high precise tracking of the debris will be necessary immediately before the engagement of the LDR and also during this engagement. By extending this tracking and ranging for a few seconds after engagement, the necessary data to evaluate the orbital modification can be produced in the same way as it is done for the catalogue generation. In our paper we discuss the object's orbit changes due to LDR operation for different locations of LDR station and different parameters of the laser energy and telescope diameter. We estimate the future orbit and re-entry parameters taking into account the influence of all important perturbation factors on the space debris orbital motion after LDR.

  8. The Implementation of Satellite Control System Software Using Object Oriented Design

    NASA Technical Reports Server (NTRS)

    Anderson, Mark O.; Reid, Mark; Drury, Derek; Hansell, William; Phillips, Tom

    1998-01-01

    NASA established the Small Explorer (SMEX) program in 1988 to provide frequent opportunities for highly focused and relatively inexpensive space science missions that can be launched into low earth orbit by small expendable vehicles. The development schedule for each SMEX spacecraft was three years from start to launch. The SMEX program has produced five satellites; Solar Anomalous and Magnetospheric Particle Explorer (SAMPEX), Fast Auroral Snapshot Explorer (FAST), Submillimeter Wave Astronomy Satellite (SWAS), Transition Region and Coronal Explorer (TRACE) and Wide-Field Infrared Explorer (WIRE). SAMPEX and FAST are on-orbit, TRACE is scheduled to be launched in April of 1998, WIRE is scheduled to be launched in September of 1998, and SWAS is scheduled to be launched in January of 1999. In each of these missions, the Attitude Control System (ACS) software was written using a modular procedural design. Current program goals require complete spacecraft development within 18 months. This requirement has increased pressure to write reusable flight software. Object-Oriented Design (OOD) offers the constructs for developing an application that only needs modification for mission unique requirements. This paper describes the OOD that was used to develop the SMEX-Lite ACS software. The SMEX-Lite ACS is three-axis controlled, momentum stabilized, and is capable of performing sub-arc-minute pointing. The paper first describes the high level requirements which governed the architecture of the SMEX-Lite ACS software. Next, the context in which the software resides is explained. The paper describes the benefits of encapsulation, inheritance and polymorphism with respect to the implementation of an ACS software system. This paper will discuss the design of several software components that comprise the ACS software. Specifically, Object-Oriented designs are presented for sensor data processing, attitude control, attitude determination and failure detection. The paper addresses the benefits of the OOD versus a conventional procedural design. The final discussion in this paper will address the establishment of the ACS Foundation Class (AFC) Library. The AFC is a large software repository, requiring a minimal amount of code modifications to produce ACS software for future projects, saving production time and costs.

  9. A History of Satellite Reconnaissance. Volume 3A - GAMBIT (REDACTED)

    DTIC Science & Technology

    1974-01-01

    In order to carry still more batteries, therefore, it was necessary to increase the thrust of the Agena upper stage by the use of High Density Acid ... HDA ) in place of the standard oxidizer. That modification allowed either an increase in orbital 295 BYE 17017-74 Handle via Byemarl Ta -T-OP-SEMET

  10. Electric-field-induced modification in Curie temperature of Co monolayer on Pt(111)

    NASA Astrophysics Data System (ADS)

    Nakamura, Kohji; Oba, Mikito; Akiyama, Toru; Ito, Tomonori; Weinert, Michael

    2015-03-01

    Magnetism induced by an external electric field (E-field) has received much attention as a potential approach for controlling magnetism at the nano-scale with the promise of ultra-low energy power consumption. Here, the E-field-induced modification of the Curie temperature for a prototypical transition-metal thin layer of a Co monolayer on Pt(111) is investigated by first-principles calculations by using the full-potential linearized augmented plane wave method that treats spin-spiral structures in an E-field. An applied E-field modifies the magnon (spin-spiral formation) energies by a few meV, which leads to a modification of the exchange pair interaction parameters within the classical Heisenberg model. With inclusion of the spin-orbit coupling (SOC), the magnetocrystalline anisotropy and the Dzyaloshinskii-Morita interaction are obtained by the second variation SOC method. An E-field-induced modification of the Curie temperature is demonstrated by Monte Carlo simulations, in which a change in the exchange interaction is found to play a key role.

  11. Integrated orbital servicing study for low-cost payload programs. Volume 2: Technical and cost analysis

    NASA Technical Reports Server (NTRS)

    Cody, E. R.; Deats, C. L.; Derocher, W. L., Jr.; Kyrias, G. M.; Snodgrass, M. R.; Sosnay, R. D.; Spencer, R. A.; Wudell, A. E.

    1975-01-01

    Orbital maintenance concepts were examined in an effort to determine a cost effective orbital maintenance system compatible with the space transportation system. An on-orbit servicer maintenance system is recommended as the most cost effective system. A pivoting arm on-orbit servicer was selected and a preliminary design was prepared. It is indicated that orbital maintenance does not have any significant impact on the space transportation system.

  12. results obtained by the application of two different methods for the calculation of optimal coplanar orbital maneuvers with time limit

    NASA Astrophysics Data System (ADS)

    Rocco, Emr; Prado, Afbap; Souza, Mlos

    In this work, the problem of bi-impulsive orbital transfers between coplanar elliptical orbits with minimum fuel consumption but with a time limit for this transfer is studied. As a first method, the equations presented by Lawden (1993) were used. Those equations furnishes the optimal transfer orbit with fixed time for this transfer, between two elliptical coplanar orbits considering fixed terminal points. The method was adapted to cases with free terminal points and those equations was solved to develop a software for orbital maneuvers. As a second method, the equations presented by Eckel and Vinh (1984) were used, those equations provide the transfer orbit between non-coplanar elliptical orbits with minimum fuel and fixed time transfer, or minimum time transfer for a prescribed fuel consumption, considering free terminal points. But in this work only the problem with fixed time transfer was considered, the case of minimum time for a prescribed fuel consumption was already studied in Rocco et al. (2000). Then, the method was modified to consider cases of coplanar orbital transfer, and develop a software for orbital maneuvers. Therefore, two software that solve the same problem using different methods were developed. The first method, presented by Lawden, uses the primer vector theory. The second method, presented by Eckel and Vinh, uses the ordinary theory of maxima and minima. So, to test the methods we choose the same terminal orbits and the same time as input. We could verify that we didn't obtain exactly the same result. In this work, that is an extension of Rocco et al. (2002), these differences in the results are explored with objective of determining the reason of the occurrence of these differences and which modifications should be done to eliminate them.

  13. Orbital shape in intentional skull deformations and adult sagittal craniosynostoses.

    PubMed

    Sandy, Ronak; Hennocq, Quentin; Nysjö, Johan; Giran, Guillaume; Friess, Martin; Khonsari, Roman Hossein

    2018-06-21

    Intentional cranial deformations are the result of external mechanical forces exerted on the skull vault that modify the morphology of various craniofacial structures such as the skull base, the orbits and the zygoma. In this controlled study, we investigated the 3D shape of the orbital inner mould and the orbital volume in various types of intentional deformations and in adult non-operated scaphocephaly - the most common type of craniosynostosis - using dedicated morphometric methods. CT scans were performed on 32 adult skulls with intentional deformations, 21 adult skull with scaphocephaly and 17 non-deformed adult skulls from the collections of the Muséum national d'Histoire naturelle in Paris, France. The intentional deformations group included six skulls with Toulouse deformations, eight skulls with circumferential deformations and 18 skulls with antero-posterior deformations. Mean shape models were generated based on a semi-automatic segmentation technique. Orbits were then aligned and compared qualitatively and quantitatively using colour-coded distance maps and by computing the mean absolute distance, the Hausdorff distance, and the Dice similarity coefficient. Orbital symmetry was assessed after mirroring, superimposition and Dice similarity coefficient computation. We showed that orbital shapes were significantly and symmetrically modified in intentional deformations and scaphocephaly compared with non-deformed control skulls. Antero-posterior and circumferential deformations demonstrated a similar and severe orbital deformation pattern resulting in significant smaller orbital volumes. Scaphocephaly and Toulouse deformations had similar deformation patterns but had no effect on orbital volumes. This study showed that intentional deformations and scaphocephaly significantly interact with orbital growth. Our approach was nevertheless not sufficient to identify specific modifications caused by the different types of skull deformations or by scaphocephaly. © 2018 Anatomical Society.

  14. Utilizing ARC EMCS Seedling Cassettes as Highly Versatile Miniature Growth Chambers for Model Organism Experiments

    NASA Technical Reports Server (NTRS)

    Freeman, John L.; Steele, Marianne K.; Sun, Gwo-Shing; Heathcote, David; Reinsch, S.; DeSimone, Julia C.; Myers, Zachary A.

    2014-01-01

    The aim of our ground testing was to demonstrate the capability of safely putting specific model organisms into dehydrated stasis, and to later rehydrate and successfully grow them inside flight proven ARC EMCS seedling cassettes. The ARC EMCS seedling cassettes were originally developed to support seedling growth during space flight. The seeds are attached to a solid substrate, launched dry, and then rehydrated in a small volume of media on orbit to initiate the experiment. We hypothesized that the same seedling cassettes should be capable of acting as culture chambers for a wide range of organisms with minimal or no modification. The ability to safely preserve live organisms in a dehydrated state allows for on orbit experiments to be conducted at the best time for crew operations and more importantly provides a tightly controlled physiologically relevant growth experiment with specific environmental parameters. Thus, we performed a series of ground tests that involved growing the organisms, preparing them for dehydration on gridded Polyether Sulfone (PES) membranes, dry storage at ambient temperatures for varying periods of time, followed by rehydration. Inside the culture cassettes, the PES membranes were mounted above blotters containing dehydrated growth media. These were mounted on stainless steel bases and sealed with plastic covers that have permeable membrane covered ports for gas exchange. The results showed we were able to demonstrate acceptable normal growth of C.elegans (nematodes), E.coli (bacteria), S.cerevisiae (yeast), Polytrichum (moss) spores and protonemata, C.thalictroides (fern), D.discoideum (amoeba), and H.dujardini (tardigrades). All organisms showed acceptable growth and rehydration in both petri dishes and culture cassettes initially, and after various time lengths of dehydration. At the end of on orbit ISS European Modular Cultivation System experiments the cassettes could be frozen at ultra-low temperatures, refrigerated, or chemically preserved before being returned to Earth for analyses. Our results suggest that with protocol modifications and future verification testing we can utilize the versatile EMCS to conduct tightly controlled experiments inside our culture cassettes for a wide variety of organisms. These physiological experiments would be designed to answer questions at the molecular level about the specific stress responses of space flight.

  15. KSC-2009-5542

    NASA Image and Video Library

    2009-10-20

    CAPE CANAVERAL, Fla. - Poised inside Vehicle Assembly Building at NASA's Kennedy Space Center in Florida, the Ares I-X rocket's upper stage is adorned with the American flag, NASA logo, and the logos of the Constellation Program, Ares, and Ares I-X. The transfer of the pad from the Space Shuttle Program to the Constellation Program took place May 31. Modifications made to the pad include the removal of shuttle unique subsystems, such as the orbiter access arm and a section of the gaseous oxygen vent arm, along with the installation of three 600-foot lightning towers, access platforms, environmental control systems and a vehicle stabilization system. Part of the Constellation Program, the Ares I-X is the test vehicle for the Ares I. The Ares I-X flight test is targeted for Oct. 27. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo credit: NASA/Kim Shiflett

  16. KSC-2009-5548

    NASA Image and Video Library

    2009-10-20

    CAPE CANAVERAL, Fla. - The Ares I-X rocket heads toward Launch Pad 39B at NASA's Kennedy Space Center in Florida, riding atop a crawler-transporter. The 4.2-mile trip to the pad from the massive Vehicle Assembly Building began at 1:39 a.m. EDT. The transfer of the pad from the Space Shuttle Program to the Constellation Program took place May 31. Modifications made to the pad include the removal of shuttle unique subsystems, such as the orbiter access arm and a section of the gaseous oxygen vent arm, along with the installation of three 600-foot lightning towers, access platforms, environmental control systems and a vehicle stabilization system. Part of the Constellation Program, the Ares I-X is the test vehicle for the Ares I. The Ares I-X flight test is targeted for Oct. 27. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo credit: NASA/Kim Shiflett

  17. KSC-2009-5543

    NASA Image and Video Library

    2009-10-20

    CAPE CANAVERAL, Fla. - With the work platforms retracted, the Ares I-X stands tall inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The platforms were retracted in preparation for the rocket's rollout to Launch Pad 39B. The transfer of the pad from the Space Shuttle Program to the Constellation Program took place May 31. Modifications made to the pad include the removal of shuttle unique subsystems, such as the orbiter access arm and a section of the gaseous oxygen vent arm, along with the installation of three 600-foot lightning towers, access platforms, environmental control systems and a vehicle stabilization system. Part of the Constellation Program, the Ares I-X is the test vehicle for the Ares I. The Ares I-X flight test is targeted for Oct. 27. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo credit: NASA/Kim Shiflett

  18. KSC-2009-5546

    NASA Image and Video Library

    2009-10-20

    CAPE CANAVERAL, Fla. - The towering 327-foot-tall Ares I-X rocket rides aboard a crawler-transporter as it exits the massive Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The rocket is bolted to its mobile launcher platform for the move to the launch pad. The transfer of the pad from the Space Shuttle Program to the Constellation Program took place May 31. Modifications made to the pad include the removal of shuttle unique subsystems, such as the orbiter access arm and a section of the gaseous oxygen vent arm, along with the installation of three 600-foot lightning towers, access platforms, environmental control systems and a vehicle stabilization system. Part of the Constellation Program, the Ares I-X is the test vehicle for the Ares I. The Ares I-X flight test is targeted for Oct. 27. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo credit: NASA/Kim Shiflett

  19. KSC-2009-5529

    NASA Image and Video Library

    2009-10-20

    CAPE CANAVERAL, Fla. – Spotlighted against the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida, the 327-foot-tall Ares I-X rocket begins its slow trek to Launch Pad 39B. The move, known as "rollout," began at 1:39 a.m. EDT. The transfer of the pad from the Space Shuttle Program to the Constellation Program took place May 31. Modifications made to the pad include the removal of shuttle unique subsystems, such as the orbiter access arm and a section of the gaseous oxygen vent arm, along with the installation of three 600-foot lightning towers, access platforms, environmental control systems and a vehicle stabilization system. Part of the Constellation Program, the Ares I-X is the test vehicle for the Ares I. The Ares I-X flight test is targeted for Oct. 27. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo credit: NASA/Jim Grossmann

  20. TOPAZ II Anti-Criticality Device Rapid Prototype

    NASA Astrophysics Data System (ADS)

    Campbell, Donald R.; Otting, William D.

    1994-07-01

    The Ballistic Missile Defense Organization (BMDO) has been working on a Nuclear Electric Propulsion Space Test Project (NEPSTP) using an existing Russian Topaz II reactor system to power the NEPSTP satellite. Safety investigations have shown that it will be possible to safely launch the Topaz II system in the United States with some modification to preclude water flooded criticality. A ``fuel-out'' water subcriticality concept was selected by the Los Alamos National Laboratory (LANL) as the baseline concept. A fuel-out anti-criticality device (ACD) conceptual design was developed by Rockwell. The concept functions to hold the fuel from the four centermost thermionic fuel elements (TFEs) outside the reactor during launch and reliably inserts the fuel into the reactor once the operational orbit is achieved. A four-tenths scale ACD rapid prototype model, fabricated from the CATIA solids design model, clearly shows in three dimensions the relative size and spatial relationship of the ACD components.

  1. Earth orbit navigation study. Volume 2: System evaluation

    NASA Technical Reports Server (NTRS)

    1972-01-01

    An overall systems evaluation was made of five candidate navigation systems in support of earth orbit missions. The five systems were horizon sensor system, unkown landmark tracking system, ground transponder system, manned space flight network, and tracking and data relay satellite system. Two reference missions were chosen: a low earth orbit mission and a transfer trajectory mission from low earth orbit to geosynchronous orbit. The specific areas addressed in the evaluation were performance, multifunction utilization, system mechanization, and cost.

  2. Application of modern tools and techniques to maximize engineering productivity in the development of orbital operations plans for the space station progrm

    NASA Technical Reports Server (NTRS)

    Manford, J. S.; Bennett, G. R.

    1985-01-01

    The Space Station Program will incorporate analysis of operations constraints and considerations in the early design phases to avoid the need for later modifications to the Space Station for operations. The application of modern tools and administrative techniques to minimize the cost of performing effective orbital operations planning and design analysis in the preliminary design phase of the Space Station Program is discussed. Tools and techniques discussed include: approach for rigorous analysis of operations functions, use of the resources of a large computer network, and providing for efficient research and access to information.

  3. Visualizing redox orbitals and their potentials in advanced lithium-ion battery materials using high-resolution x-ray Compton scattering

    DOE PAGES

    Hafiz, Hasnain; Suzuki, Kosuke; Barbiellini, Bernardo; ...

    2017-08-02

    Reduction-oxidation (redox) reactions are the key processes that underlie the batteries powering smartphones, laptops, and electric cars. A redox process involves transfer of electrons between two species. For example, in a lithium-ion battery, current is generated when conduction electrons from the lithium anode are transferred to the redox orbitals of the cathode material. The ability to visualize or image the redox orbitals and how these orbitals evolve under lithiation and delithiation processes is thus of great fundamental and practical interest for understanding the workings of battery materials. In this study, we show that inelastic scattering spectroscopy using high-energy x-ray photonsmore » (Compton scattering) can yield faithful momentum space images of the redox orbitals by considering lithium iron phosphate (LiFePO 4 or LFP) as an exemplar cathode battery material. Our analysis reveals a new link between voltage and the localization of transition metal 3d orbitals and provides insight into the puzzling mechanism of potential shift and how it is connected to the modification of the bond between the transition metal and oxygen atoms. Our study thus opens a novel spectroscopic pathway for improving the performance of battery materials.« less

  4. Visualizing redox orbitals and their potentials in advanced lithium-ion battery materials using high-resolution x-ray Compton scattering

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hafiz, Hasnain; Suzuki, Kosuke; Barbiellini, Bernardo

    Reduction-oxidation (redox) reactions are the key processes that underlie the batteries powering smartphones, laptops, and electric cars. A redox process involves transfer of electrons between two species. For example, in a lithium-ion battery, current is generated when conduction electrons from the lithium anode are transferred to the redox orbitals of the cathode material. The ability to visualize or image the redox orbitals and how these orbitals evolve under lithiation and delithiation processes is thus of great fundamental and practical interest for understanding the workings of battery materials. In this study, we show that inelastic scattering spectroscopy using high-energy x-ray photonsmore » (Compton scattering) can yield faithful momentum space images of the redox orbitals by considering lithium iron phosphate (LiFePO 4 or LFP) as an exemplar cathode battery material. Our analysis reveals a new link between voltage and the localization of transition metal 3d orbitals and provides insight into the puzzling mechanism of potential shift and how it is connected to the modification of the bond between the transition metal and oxygen atoms. Our study thus opens a novel spectroscopic pathway for improving the performance of battery materials.« less

  5. Analytical Modeling of Pressure Wall Hole Size and Maximum Tip-to-Tip Crack Length for Perforating Normal and Oblique Orbital Debris Impacts

    NASA Technical Reports Server (NTRS)

    Schonberg, William P.; Mohamed, Essam

    1997-01-01

    This report presents the results of a study whose objective was to develop first-principles-based models of hole size and maximum tip-to-tip crack length for a spacecraft module pressure wall that has been perforated in an orbital debris particle impact. The hole size and crack length models are developed by sequentially characterizing the phenomena comprising the orbital debris impact event, including the initial impact, the creation and motion of a debris cloud within the dual-wall system, the impact of the debris cloud on the pressure wall, the deformation of the pressure wall due to debris cloud impact loading prior to crack formation, pressure wall crack initiation, propagation, and arrest, and finally pressure wall deformation following crack initiation and growth. The model development has been accomplished through the application of elementary shock physics and thermodynamic theory, as well as the principles of mass, momentum, and energy conservation. The predictions of the model developed herein are compared against the predictions of empirically-based equations for hole diameters and maximum tip-to-tip crack length for three International Space Station wall configurations. The ISS wall systems considered are the baseline U.S. Lab Cylinder, the enhanced U.S. Lab Cylinder, and the U.S. Lab Endcone. The empirical predictor equations were derived from experimentally obtained hole diameters and crack length data. The original model predictions did not compare favorably with the experimental data, especially for cases in which pressure wall petalling did not occur. Several modifications were made to the original model to bring its predictions closer in line with the experimental results. Following the adjustment of several empirical constants, the predictions of the modified analytical model were in much closer agreement with the experimental results.

  6. Electronic modification of Cu-based chalcopyrite semiconductors induced by lattice deformation and composition alchemy

    NASA Astrophysics Data System (ADS)

    Jiang, F. D.; Feng, J. Y.

    2008-02-01

    Using first principles calculation, we systematically investigate the electronic modification of Cu-based chalcopyrite semiconductors induced by lattice deformation and composition alchemy. It is shown that the optical band gap Eg is remarkably sensitive to the anion displacement μ, resulting from the opposite shifts of conduction band minimum and valence band maximum. Meanwhile, the dependence of structural parameters of alloyed compounds on alloy composition x is demonstrated for both cation and anion alloying. The d orbitals of group-III cations are found to be of great importance in the calculation. Abnormal changes in the optical band gap Eg induced by anion alloying are addressed.

  7. Re-use of Science Operations Systems around Mars: from Mars Express to ExoMars

    NASA Astrophysics Data System (ADS)

    Cardesin-Moinelo, Alejandro; Mars Express Operations Centre; ExoMars Science Operations Centre

    2017-10-01

    Mars Express and ExoMars 2016 Trace Gas Orbiter are the only two ESA planetary missions currently in operations, and they happen to be around the same planet! These two missions have great potential for synergies between their science objectives, instruments and observation capabilities and they can all be combined to improve the scientific outcome and improve our knowledge about Mars. In this contribution we will give a short summary of both missions, with an insight in its similarities and differences regarding their scientific and operational challenges, and we will summarize the lessons learned from Mars Express and how the existing science operations systems, processes and tools have been reused, redesigned and adapted in order to satisfy the operational requirements of ExoMars, with limited development resources thanks to the inherited capabilities from previous missions. In particular we will focus on the preparations done by the science operations centers at ESAC and the work within the Science Ground Segments for the re-use of the SPICE and MAPPS software tools, with the necessary modifications and upgrades to perform the geometrical and operational simulations of both spacecrafts, taking into account the specific instrument modelling, observation requirements and all the payload and spacecraft operational rules and constraints for feasibility checks. All of these system upgrades are now being finalized for ExoMars and some of them have already been rehearsed in orbit, getting ready for the nominal science operations phase starting in the first months of 2018 after the aerobraking phase

  8. Fire, ice, water, and dirt: A simple climate model

    NASA Astrophysics Data System (ADS)

    Kroll, John

    2017-07-01

    A simple paleoclimate model was developed as a modeling exercise. The model is a lumped parameter system consisting of an ocean (water), land (dirt), glacier, and sea ice (ice) and driven by the sun (fire). In comparison with other such models, its uniqueness lies in its relative simplicity yet yielding good results. For nominal values of parameters, the system is very sensitive to small changes in the parameters, yielding equilibrium, steady oscillations, and catastrophes such as freezing or boiling oceans. However, stable solutions can be found, especially naturally oscillating solutions. For nominally realistic conditions, natural periods of order 100kyrs are obtained, and chaos ensues if the Milankovitch orbital forcing is applied. An analysis of a truncated system shows that the naturally oscillating solution is a limit cycle with the characteristics of a relaxation oscillation in the two major dependent variables, the ocean temperature and the glacier ice extent. The key to getting oscillations is having the effective emissivity decreasing with temperature and, at the same time, the effective ocean albedo decreases with increasing glacier extent. Results of the original model compare favorably to the proxy data for ice mass variation, but not for temperature variation. However, modifications to the effective emissivity and albedo can be made to yield much more realistic results. The primary conclusion is that the opinion of Saltzman [Clim. Dyn. 5, 67-78 (1990)] is plausible that the external Milankovitch orbital forcing is not sufficient to explain the dominant 100kyr period in the data.

  9. Fire, ice, water, and dirt: A simple climate model.

    PubMed

    Kroll, John

    2017-07-01

    A simple paleoclimate model was developed as a modeling exercise. The model is a lumped parameter system consisting of an ocean (water), land (dirt), glacier, and sea ice (ice) and driven by the sun (fire). In comparison with other such models, its uniqueness lies in its relative simplicity yet yielding good results. For nominal values of parameters, the system is very sensitive to small changes in the parameters, yielding equilibrium, steady oscillations, and catastrophes such as freezing or boiling oceans. However, stable solutions can be found, especially naturally oscillating solutions. For nominally realistic conditions, natural periods of order 100kyrs are obtained, and chaos ensues if the Milankovitch orbital forcing is applied. An analysis of a truncated system shows that the naturally oscillating solution is a limit cycle with the characteristics of a relaxation oscillation in the two major dependent variables, the ocean temperature and the glacier ice extent. The key to getting oscillations is having the effective emissivity decreasing with temperature and, at the same time, the effective ocean albedo decreases with increasing glacier extent. Results of the original model compare favorably to the proxy data for ice mass variation, but not for temperature variation. However, modifications to the effective emissivity and albedo can be made to yield much more realistic results. The primary conclusion is that the opinion of Saltzman [Clim. Dyn. 5, 67-78 (1990)] is plausible that the external Milankovitch orbital forcing is not sufficient to explain the dominant 100kyr period in the data.

  10. FERMI/GLAST Integrated Trending and Plotting System Release 5.0

    NASA Technical Reports Server (NTRS)

    Ritter, Sheila; Brumer, Haim; Reitan, Denise

    2012-01-01

    An Integrated Trending and Plotting System (ITPS) is a trending, analysis, and plotting system used by space missions to determine performance and status of spacecraft and its instruments. ITPS supports several NASA mission operational control centers providing engineers, ground controllers, and scientists with access to the entire spacecraft telemetry data archive for the life of the mission, and includes a secure Web component for remote access. FERMI/GLAST ITPS Release 5.0 features include the option to display dates (yyyy/ddd) instead of orbit numbers along orbital Long-Term Trend (LTT) plot axis, the ability to save statistics from daily production plots as image files, and removal of redundant edit/create Input Definition File (IDF) screens. Other features are a fix to address invalid packet lengths, a change in naming convention of image files in order to use in script, the ability to save all ITPS plot images (from Windows or the Web) as GIF or PNG format, the ability to specify ymin and ymax on plots where previously only the desired range could be specified, Web interface capability to plot IDFs that contain out-oforder page and plot numbers, and a fix to change all default file names to show yyyydddhhmmss time stamps instead of hhmmssdddyyyy. A Web interface capability sorts files based on modification date (with newest one at top), and the statistics block can be displayed via a Web interface. Via the Web, users can graphically view the volume of telemetry data from each day contained in the ITPS archive in the Web digest. The ITPS could be also used in nonspace fields that need to plot data or trend data, including financial and banking systems, aviation and transportation systems, healthcare and educational systems, sales and marketing, and housing and construction.

  11. Investigation of configuration effects on entry heating distributions at Mach no. equal 8.0 (OH41). [for wind tunnel model of space shuttle orbiter

    NASA Technical Reports Server (NTRS)

    Gorowitz, H.; White, R.; Derrico, A.

    1973-01-01

    Aerodynamic heating data were obtained on 0.006 scale models of four Rockwell International SSV double delta wing Orbiters in the Mach 8 variable density tunnel. A model of two previously tested Rockwell International Orbiters which are identified in the Configuration Description of this report were also tested. Orbiter surfaces were thermally mapped from the laminar through turbulent flight regimes during re-entry. Various modifications were made to model lower surfaces to determine the cause of transition in the vicinity of 3.0 million Reynolds number per foot. Re-entry data were acquired for angles of attack from 25 through 35 degrees at nominal Reynolds numbers per foot of 1.0, 2.0, 2.3, 2.5, 3.0, 3.5, 4.5 and 6.0 million utilizing the phase change paint technique. Launch data were acquired on the model upper surfaces for angles of attack of 0 and -5 degrees at nominal Reynolds numbers per foot of 3.0 and 6.0 million. A total of 70 orbiter heating runs and 6 material sample sphere runs were completed.

  12. The SCRAM tool-kit

    NASA Technical Reports Server (NTRS)

    Tamir, David; Flanigan, Lee A.; Weeks, Jack L.; Siewert, Thomas A.; Kimbrough, Andrew G.; Mcclure, Sidney R.

    1994-01-01

    This paper proposes a new series of on-orbit capabilities to support the near-term Hubble Space Telescope, Extended Duration Orbiter, Long Duration Orbiter, Space Station Freedom, other orbital platforms, and even the future manned Lunar/Mars missions. These proposed capabilities form a toolkit termed Space Construction, Repair, and Maintenance (SCRAM). SCRAM addresses both intra-Vehicular Activity (IVA) and Extra-Vehicular Activity (EVA) needs. SCRAM provides a variety of tools which enable welding, brazing, cutting, coating, heating, and cleaning, as well as corresponding nondestructive examination. Near-term IVA-SCRAM applications include repair and modification to fluid lines, structure, and laboratory equipment inside a shirt-sleeve environment (i.e. inside Spacelab or Space Station). Near-term EVA-SCRAM applications include construction of fluid lines and structural members, repair of punctures by orbital debris, refurbishment of surfaces eroded by contaminants. The SCRAM tool-kit also promises future EVA applications involving mass production tasks automated by robotics and artificial intelligence, for construction of large truss, aerobrake, and nuclear reactor shadow shields structures. The leading candidate tool processes for SCRAM, currently undergoing research and development, include Electron Beam, Gas Tungsten Arc, Plasma Arc, and Laser Beam. A series of strategic space flight experiments would make SCRAM available to help conquer the space frontier.

  13. Core heat convection in NSTX-U via modification of electron orbits by high frequency Alfvén eigenmodes

    NASA Astrophysics Data System (ADS)

    Crocker, N. A.; Tritz, K.; White, R. B.; Fredrickson, E. D.; Gorelenkov, N. N.; NSTX-U Team

    2015-11-01

    New simulation results demonstrate that high frequency compressional (CAE) and global (GAE) Alfvén eigenmodes cause radial convection of electrons, with implications for particle and energy confinement, as well as electric field formation in NSTX-U. Simulations of electron orbits in the presence of multiple experimentally determined CAEs and GAEs, using the gyro-center code ORBIT, have revealed substantial convective transport, in addition to the expected diffusion via orbit stochastization. These results advance understanding of anomalous core energy transport expected in high performance, beam-heated NSTX-U plasmas. The simulations make use of experimentally determined density perturbation (δn) amplitudes and mode structures obtained by inverting measurements from 16 a channel reflectometer array using a synthetic diagnostic. Combined with experimentally determined mode polarizations (i.e. CAE or GAE), the δn are used to estimate the ExB displacements for use in ORBIT. Preliminary comparison of the simulation results with transport modeling by TRANSP indicate that the convection is currently underestimated. Supported by US DOE Contracts DE-SC0011810, DE-FG02-99ER54527 & DE-AC02-09CH11466.

  14. An Advanced Photovoltaic Array Regulator Module

    NASA Technical Reports Server (NTRS)

    Button, Robert M.

    1996-01-01

    Current trends in satellite design are focused on developing small, reliable, and inexpensive spacecraft. To that end, a modular power management and distribution system is proposed which will help transition the aerospace industry towards an assembly line approach to building spacecraft. The modular system is based on an innovative DC voltage boost converter called the Series Connected Boost Unit (SCBU). The SCBU uses any isolating DC-DC converter and adds a unique series connection. This simple modification provides the SCBU topology with many advantages over existing boost converters. Efficiencies of 94-98%, power densities above 1,000 W/kg, and inherent fault tolerance are just a few of the characteristics presented. Limitations of the SCBU technology are presented, and it is shown that the SCBU makes an ideal photovoltaic an-ay regulator. A set of photovoltaic power system requirements are presented that can be applied to almost any low Earth orbit satellite. Finally, a modular design based on the series connected boost unit is outlined and functional descriptions of the components are given.

  15. The asteroid rendezvous spacecraft. An adaptation study of TIROS/DMSP technology

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The feasibility of using the TIROS/DMSP Earth orbiting meteorological satellite in application to a near Earth asteroid rendezvous mission. System and subsystems analysis was carried out to develop a configuration of the spacecraft suitable for this mission. Mission analysis studies were also done and maneuver/rendezvous scenarios developed for baseline missions to both Anteros and Eros. The fact that the Asteroid mission is the most complex of the Pioneer class missions currently under consideration notwithstanding, the basic conclusion very strongly supports the suitability of the basic TIROS bus for this mission in all systems and subsystems areas, including science accommodation. Further, the modifications which are required due to the unique mission are very low risk and can be accomplished readily. The key issue is that in virtually every key subsystem, the demands of the Asteroid mission are a subset of the basic meteorological satellite mission. This allows a relatively simple reconfiguration to be accomplished without a major system redesign.

  16. KSC-2009-5915

    NASA Image and Video Library

    2009-10-27

    CAPE CANAVERAL, Fla. – Sunrise at Launch Pad 39B at NASA's Kennedy Space Center in Florida reveals the rotating service structure and the arms of the vehicle stabilization system have been retracted from around the Constellation Program's 327-foot-tall Ares I-X rocket for launch. The transfer of the pad from the Space Shuttle Program to the Constellation Program took place May 31. Modifications made to the pad include the removal of shuttle unique subsystems, such as the orbiter access arm and a section of the gaseous oxygen vent arm, and the installation of three 600-foot lightning towers, access platforms, environmental control systems and a vehicle stabilization system. The data returned from more than 700 sensors throughout the rocket will be used to refine the design of future launch vehicles and bring NASA one step closer to reaching its exploration goals. The Ares I-X flight test is targeted for Oct. 27. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo credit: NASA/Kim Shiflett

  17. KSC-04pd0950

    NASA Image and Video Library

    2004-04-21

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, the left-hand Orbital Maneuvering System (OMS) pod is lowered toward the orbiter Discovery for installation. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

  18. KSC-04pd0948

    NASA Image and Video Library

    2004-04-21

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, the left-hand Orbital Maneuvering System (OMS) pod is maneuvered toward the engine interfaces on the orbiter Discovery for installation. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

  19. TORCAPP: time-dependent cyclotron orbit calculation and plotting package

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Malarkey, C.H.; McNeilly, G.S.; Merriman, L.D.

    1982-11-01

    This addendum describes the modifications and additions to TORCAPP which have been implemented since the original report was issued in November 1979 by L.B. Maddox and G.S. McNeilly. Major changes include input of electric field data for central region studies, provision for extractor elements to allow extraction studies, and three-dimensional tracking of central rays.

  20. Early Rockets

    NASA Image and Video Library

    1958-01-31

    Jupiter-C Missile No. 27 assembly at the Army Ballistic Missile Agency (ABMA), Redstone Arsenal, in Huntsville, Aalabama. The Jupiter-C was a modification of the Redstone Missile, and originally developed as a nose cone re-entry test vehicle for the Jupiter Intermediate Range Ballistic Missile (IRBM). Jupiter-C successfully launched the first American Satellite, Explorer 1, in orbit on January 31, 1958.

  1. Mission Analysis Program for Solar Electric Propulsion (MAPSEP). Volume 3: Program manual for earth orbital MAPSEP

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A revised user's manual for the computer program MAPSEP is presented. Major changes from the interplanetary version of MAPSEP are summarized. The changes are intended to provide a basic capability to analyze anticipated solar electric missions, and a foundation for future more complex, modifications. For Vol. III, N75-16589.

  2. Use of Human Modeling Simulation Software in the Task Analysis of the Environmental Control and Life Support System Component Installation Procedures

    NASA Technical Reports Server (NTRS)

    Estes, Samantha; Parker, Nelson C. (Technical Monitor)

    2001-01-01

    Virtual reality and simulation applications are becoming widespread in human task analysis. These programs have many benefits for the Human Factors Engineering field. Not only do creating and using virtual environments for human engineering analyses save money and time, this approach also promotes user experimentation and provides increased quality of analyses. This paper explains the human engineering task analysis performed on the Environmental Control and Life Support System (ECLSS) space station rack and its Distillation Assembly (DA) subsystem using EAI's human modeling simulation software, Jack. When installed on the International Space Station (ISS), ECLSS will provide the life and environment support needed to adequately sustain crew life. The DA is an Orbital Replaceable Unit (ORU) that provides means of wastewater (primarily urine from flight crew and experimental animals) reclamation. Jack was used to create a model of the weightless environment of the ISS Node 3, where the ECLSS is housed. Computer aided drawings of the ECLSS rack and DA system were also brought into the environment. Anthropometric models of a 95th percentile male and 5th percentile female were used to examine the human interfaces encountered during various ECLSS and DA tasks. The results of the task analyses were used in suggesting modifications to hardware and crew task procedures to improve accessibility, conserve crew time, and add convenience for the crew. This paper will address some of those suggested modifications and the method of presenting final analyses for requirements verification.

  3. A study of an orbital radar mapping mission to Venus. Volume 3: Parametric studies and subsystem comparisons

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Parametric studies and subsystem comparisons for the orbital radar mapping mission to planet Venus are presented. Launch vehicle requirements and primary orbiter propulsion system requirements are evaluated. The systems parametric analysis indicated that orbit size and orientation interrelated with almost all of the principal spacecraft systems and influenced significantly the definition of orbit insertion propulsion requirements, weight in orbit capability, radar system design, and mapping strategy.

  4. The Exo-S probe class starshade mission

    NASA Astrophysics Data System (ADS)

    Seager, Sara; Turnbull, Margaret; Sparks, William; Thomson, Mark; Shaklan, Stuart B.; Roberge, Aki; Kuchner, Marc; Kasdin, N. Jeremy; Domagal-Goldman, Shawn; Cash, Webster; Warfield, Keith; Lisman, Doug; Scharf, Dan; Webb, David; Trabert, Rachel; Martin, Stefan; Cady, Eric; Heneghan, Cate

    2015-09-01

    Exo-S is a direct imaging space-based mission to discover and characterize exoplanets. With its modest size, Exo-S bridges the gap between census missions like Kepler and a future space-based flagship direct imaging exoplanet mission. With the ability to reach down to Earth-size planets in the habitable zones of nearly two dozen nearby stars, Exo-S is a powerful first step in the search for and identification of Earth-like planets. Compelling science can be returned at the same time as the technological and scientific framework is developed for a larger flagship mission. The Exo-S Science and Technology Definition Team studied two viable starshade-telescope missions for exoplanet direct imaging, targeted to the $1B cost guideline. The first Exo-S mission concept is a starshade and telescope system dedicated to each other for the sole purpose of direct imaging for exoplanets (The "Starshade Dedicated Mission"). The starshade and commercial, 1.1-m diameter telescope co-launch, sharing the same low-cost launch vehicle, conserving cost. The Dedicated mission orbits in a heliocentric, Earth leading, Earth-drift away orbit. The telescope has a conventional instrument package that includes the planet camera, a basic spectrometer, and a guide camera. The second Exo-S mission concept is a starshade that launches separately to rendezvous with an existing on-orbit space telescope (the "Starshade Rendezvous Mission"). The existing telescope adopted for the study is the WFIRST-AFTA (Wide-Field Infrared Survey Telescope Astrophysics Focused Telescope Asset). The WFIRST-AFTA 2.4-m telescope is assumed to have previously launched to a Halo orbit about the Earth-Sun L2 point, away from the gravity gradient of Earth orbit which is unsuitable for formation flying of the starshade and telescope. The impact on WFIRST-AFTA for starshade readiness is minimized; the existing coronagraph instrument performs as the starshade science instrument, while formation guidance is handled by the existing coronagraph focal planes with minimal modification and an added transceiver.

  5. Weak Localization and Antilocalization in Topological Materials with Impurity Spin-Orbit Interactions

    PubMed Central

    Hankiewicz, Ewelina M.; Culcer, Dimitrie

    2017-01-01

    Topological materials have attracted considerable experimental and theoretical attention. They exhibit strong spin-orbit coupling both in the band structure (intrinsic) and in the impurity potentials (extrinsic), although the latter is often neglected. In this work, we discuss weak localization and antilocalization of massless Dirac fermions in topological insulators and massive Dirac fermions in Weyl semimetal thin films, taking into account both intrinsic and extrinsic spin-orbit interactions. The physics is governed by the complex interplay of the chiral spin texture, quasiparticle mass, and scalar and spin-orbit scattering. We demonstrate that terms linear in the extrinsic spin-orbit scattering are generally present in the Bloch and momentum relaxation times in all topological materials, and the correction to the diffusion constant is linear in the strength of the extrinsic spin-orbit. In topological insulators, which have zero quasiparticle mass, the terms linear in the impurity spin-orbit coupling lead to an observable density dependence in the weak antilocalization correction. They produce substantial qualitative modifications to the magnetoconductivity, differing greatly from the conventional Hikami-Larkin-Nagaoka formula traditionally used in experimental fits, which predicts a crossover from weak localization to antilocalization as a function of the extrinsic spin-orbit strength. In contrast, our analysis reveals that topological insulators always exhibit weak antilocalization. In Weyl semimetal thin films having intermediate to large values of the quasiparticle mass, we show that extrinsic spin-orbit scattering strongly affects the boundary of the weak localization to antilocalization transition. We produce a complete phase diagram for this transition as a function of the mass and spin-orbit scattering strength. Throughout the paper, we discuss implications for experimental work, and, at the end, we provide a brief comparison with transition metal dichalcogenides. PMID:28773167

  6. Nickel hydrogen battery expert system

    NASA Technical Reports Server (NTRS)

    Shiva, Sajjan G.

    1991-01-01

    The Hubble Telescope Battery Testbed at MSFC uses the Nickel Cadmium (NiCd) Battery Expert System (NICBES-2) which supports the evaluation of performance of Hubble Telescope spacecraft batteries and provides alarm diagnosis and action advice. NICBES-2 provides a reasoning system along with a battery domain knowledge base to achieve this battery health management function. An effort is summarized which was used to modify NICBES-2 to accommodate Nickel Hydrogen (NiH2) battery environment now in MSFC testbed. The NICBES-2 is implemented on a Sun Microsystem and is written in SunOS C and Quintus Prolog. The system now operates in a multitasking environment. NICBES-2 spawns three processes: serial port process (SPP); data handler process (DHP); and the expert system process (ESP) in order to process the telemetry data and provide the status and action advice. NICBES-2 performs orbit data gathering, data evaluation, alarm diagnosis and action advice and status and history display functions. The adaptation of NICBES-2 to work with NiH2 battery environment required modification to all of the three component processes.

  7. Software and Human-Machine Interface Development for Environmental Controls Subsystem Support

    NASA Technical Reports Server (NTRS)

    Dobson, Matthew

    2018-01-01

    The Space Launch System (SLS) is the next premier launch vehicle for NASA. It is the next stage of manned space exploration from American soil, and will be the platform in which we push further beyond Earth orbit. In preparation of the SLS maiden voyage on Exploration Mission 1 (EM-1), the existing ground support architecture at Kennedy Space Center required significant overhaul and updating. A comprehensive upgrade of controls systems was necessary, including programmable logic controller software, as well as Launch Control Center (LCC) firing room and local launch pad displays for technician use. Environmental control acts as an integral component in these systems, being the foremost system for conditioning the pad and extremely sensitive launch vehicle until T-0. The Environmental Controls Subsystem (ECS) required testing and modification to meet the requirements of the designed system, as well as the human factors requirements of NASA software for Validation and Verification (V&V). This term saw significant strides in the progress and functionality of the human-machine interfaces used at the launch pad, and improved integration with the controller code.

  8. Charge instability in double quantum dots in Ge/Si core/shell nanowires

    NASA Astrophysics Data System (ADS)

    Zarassi, Azarin; Su, Zhaoen; Schwenderling, Jens; Frolov, Sergey M.; Hocevar, Moïra; Nguyen, Binh-Minh; Yoo, Jinkyoung; Dayeh, Shadi A.

    Controlling dephasing times are of great challenge in the studies of spin qubit. Reported long spin coherence time and predicted strong spin-orbit interaction of holes in Ge/Si core/shell nanowires, as well as their weak coupling to very few nuclear spins of these group IV semiconductors, persuade electrical spin control. We have established Pauli spin blockade in gate-tunable quantum dots formed in these nanowires. The g-factor has been measured and evidence of spin-orbit interaction has been observed in the presence of magnetic field. However, electrical control of spins requires considerable stability in the double dot configuration, and imperfectly these dots suffer from poor stability. We report on fabrication modifications on Ge/Si core/shell nanowires, as well as measurement techniques to suppress the charge instabilities and ease the way to study spin-orbit coupling and resolve electric dipole spin resonance.

  9. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hégely, Bence; Nagy, Péter R.; Kállay, Mihály, E-mail: kallay@mail.bme.hu

    Exact schemes for the embedding of density functional theory (DFT) and wave function theory (WFT) methods into lower-level DFT or WFT approaches are introduced utilizing orbital localization. First, a simple modification of the projector-based embedding scheme of Manby and co-workers [J. Chem. Phys. 140, 18A507 (2014)] is proposed. We also use localized orbitals to partition the system, but instead of augmenting the Fock operator with a somewhat arbitrary level-shift projector we solve the Huzinaga-equation, which strictly enforces the Pauli exclusion principle. Second, the embedding of WFT methods in local correlation approaches is studied. Since the latter methods split up themore » system into local domains, very simple embedding theories can be defined if the domains of the active subsystem and the environment are treated at a different level. The considered embedding schemes are benchmarked for reaction energies and compared to quantum mechanics (QM)/molecular mechanics (MM) and vacuum embedding. We conclude that for DFT-in-DFT embedding, the Huzinaga-equation-based scheme is more efficient than the other approaches, but QM/MM or even simple vacuum embedding is still competitive in particular cases. Concerning the embedding of wave function methods, the clear winner is the embedding of WFT into low-level local correlation approaches, and WFT-in-DFT embedding can only be more advantageous if a non-hybrid density functional is employed.« less

  10. Multi-Mission Power Analysis Tool (MMPAT) Version 3

    NASA Technical Reports Server (NTRS)

    Wood, Eric G.; Chang, George W.; Chen, Fannie C.

    2012-01-01

    The Multi-Mission Power Analysis Tool (MMPAT) simulates a spacecraft power subsystem including the power source (solar array and/or radioisotope thermoelectric generator), bus-voltage control, secondary battery (lithium-ion or nickel-hydrogen), thermostatic heaters, and power-consuming equipment. It handles multiple mission types including heliocentric orbiters, planetary orbiters, and surface operations. Being parametrically driven along with its user-programmable features can reduce or even eliminate any need for software modifications when configuring it for a particular spacecraft. It provides multiple levels of fidelity, thereby fulfilling the vast majority of a project s power simulation needs throughout the lifecycle. It can operate in a stand-alone mode with a graphical user interface, in batch mode, or as a library linked with other tools. This software can simulate all major aspects of a spacecraft power subsystem. It is parametrically driven to reduce or eliminate the need for a programmer. Added flexibility is provided through user-designed state models and table-driven parameters. MMPAT is designed to be used by a variety of users, such as power subsystem engineers for sizing power subsystem components; mission planners for adjusting mission scenarios using power profiles generated by the model; system engineers for performing system- level trade studies using the results of the model during the early design phases of a spacecraft; and operations personnel for high-fidelity modeling of the essential power aspect of the planning picture.

  11. 47 CFR 25.164 - Milestones.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Milestones. (a) Licensees of geostationary orbit satellite systems other than DBS and DARS satellite systems.... (b) Licensees of non-geostationary orbit satellite systems other than DBS and DARS satellite systems... both non-geostationary orbit satellites and geostationary orbit satellites, other than DBS and DARS...

  12. 47 CFR 25.164 - Milestones.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Milestones. (a) Licensees of geostationary orbit satellite systems other than DBS and DARS satellite systems.... (b) Licensees of non-geostationary orbit satellite systems other than DBS and DARS satellite systems... both non-geostationary orbit satellites and geostationary orbit satellites, other than DBS and DARS...

  13. 47 CFR 25.164 - Milestones.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Milestones. (a) Licensees of geostationary orbit satellite systems other than DBS and DARS satellite systems.... (b) Licensees of non-geostationary orbit satellite systems other than DBS and DARS satellite systems... both non-geostationary orbit satellites and geostationary orbit satellites, other than DBS and DARS...

  14. 47 CFR 25.164 - Milestones.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Milestones. (a) Licensees of geostationary orbit satellite systems other than DBS and DARS satellite systems.... (b) Licensees of non-geostationary orbit satellite systems other than DBS and DARS satellite systems... both non-geostationary orbit satellites and geostationary orbit satellites, other than DBS and DARS...

  15. Significant results from Apollo 14 lunar orbital photography.

    NASA Technical Reports Server (NTRS)

    El-Baz, F.; Roosa, S. A.

    1972-01-01

    Apollo 14 obtained 950 photographs from lunar orbit using the Hasselblad and Hycon cameras. The photographs reveal a number of new geologic features as well as previously unrecognized details of the morphology, structure, and stratigraphy of lunar surface units. The primary result is the verification of the extensive role of volcanism in the formation and modification of the lunar highlands, especially on the far side. Terra volcanism appears to be manifest in the formation of (1) constructional units of hilly and furrowed materials of regional extent as in the Kant Plateau in the central near-side highlands and northwest of the crater Pasteur near the eastern limb of the moon; (2) somewhat viscous lava flows and pools associated with fracture systems and/or what appear to be volcanic craters; (3) craters, crater chains, and irregular depressions, particularly on the lunar far side. The first photographs of a flow channel, a leveed sinuous rille that apparently originated by lava flowage on the surface, were obtained by Apollo 14. Another first is a high-resolution photograph of the interior of what appears to be the youngest lunar crater yet photographed in the 20- 40-km size range.

  16. Managing the patient with oculomotor nerve palsy.

    PubMed

    Sadagopan, Karthikeyan A; Wasserman, Barry N

    2013-09-01

    To provide clinically relevant information regarding the evaluation and current treatment options for oculomotor nerve palsies. We survey recent literature and provide some insights into these studies. Recent case reports highlight emerging new causes of oculomotor cranial nerve palsies, including sellar chordoma, odontogenic abscess, nonaneurysmal subarachnoid hemorrhage, polycythemia, sphenoiditis, neurobrucellosis, interpeduncular fossa lipoma, metastatic pancreatic cancer, leukemia, and lymphoma. Surgical studies have focused on modifications and innovations regarding strabismus surgery for this condition. New globe fixation procedures may include fixation to the medial orbital wall by precaruncular and retrocaruncular approaches, apically based orbital bone periosteal flap fixation and the suture/T-plate anchoring platform system. Management of oculomotor nerve palsy depends in part upon the underlying cause and anatomical location of the lesion. Careful clinical evaluation and appropriate imaging can identify a definitive cause in most cases. Surgical options depend on the number, extent, and severity of the muscles involved as well as the presence or absence of signs of aberrant regeneration. The clinician should also address issues that arise due to involvement of the pupil and accommodation. Strabismus surgery can be challenging but also rewarding with appropriate selection and staging of procedures.

  17. KSC-04pd0942

    NASA Image and Video Library

    2004-04-21

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, the left-hand Orbital Maneuvering System (OMS) pod (seen from the back) is lifted off its transporter. The OMS pod will be installed on the orbiter Discovery. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

  18. KSC-04pd0949

    NASA Image and Video Library

    2004-04-21

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, workers stand by as the left-hand Orbital Maneuvering System (OMS) pod is maneuvered toward the engine interfaces on the orbiter Discovery for installation. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

  19. KSC-04pd0944

    NASA Image and Video Library

    2004-04-21

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, the left-hand Orbital Maneuvering System (OMS) pod is lifted at an angle from the transporter below. The OMS pod will be installed on the orbiter Discovery. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

  20. KSC-04pd0947

    NASA Image and Video Library

    2004-04-21

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, the left-hand Orbital Maneuvering System (OMS) pod (top of photo) is poised behind the engine interfaces on the orbiter Discovery for installation. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

  1. KSC-04pd0946

    NASA Image and Video Library

    2004-04-21

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, workers on an upper level watch as the left-hand Orbital Maneuvering System (OMS) pod is lifted high to maneuver it toward the orbiter Discovery for installation. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

  2. KSC-04pd0943

    NASA Image and Video Library

    2004-04-21

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, workers check the lifting of the left-hand Orbital Maneuvering System (OMS) pod. The OMS pod will be installed on the orbiter Discovery. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

  3. KSC-04pd0941

    NASA Image and Video Library

    2004-04-21

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, the left-hand Orbital Maneuvering System (OMS) pod (seen from the front) is lifted off its transporter. The OMS pod will be installed on the orbiter Discovery. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

  4. KSC-04pd0945

    NASA Image and Video Library

    2004-04-21

    KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, a worker on an upper level watches as the left-hand Orbital Maneuvering System (OMS) pod is lifted high to maneuver it toward the orbiter Discovery for installation. The Orbital Maneuvering System provides the thrust for orbit insertion, orbit circularization, orbit transfer, rendezvous, deorbit, abort to orbit and abort once around. It can provide up to 1,000 pounds of propellant to the aft reaction control system. Each pod contains one OMS engine and the hardware needed to pressurize, store and distribute the propellants to perform the velocity maneuvers.

  5. Modification of band gaps and optoelectronic properties of binary calcium chalcogenides by means of doping of magnesium atom(s) in rock-salt phase- a first principle based theoretical initiative

    NASA Astrophysics Data System (ADS)

    Debnath, Bimal; Sarkar, Utpal; Debbarma, Manish; Bhattacharjee, Rahul; Chattopadhyaya, Surya

    2018-02-01

    The band gaps and optoelectronic properties of binary calcium chalcogenide semiconductors have been modified theoretically by doping magnesium atom(s) into their respective rock-salt unit cells at some specific concentrations x = 0.0, 0.25, 0.50, 0.75 and 1.0 and confirmed such modifications by studying their structural, electronic and optical properties using DFT based FP-LAPW approach. The WC-GGA functional is used to calculate structural properties, while mBJ, B3LYP and WC-GGA are used for calculating electronic and optical properties. The concentration dependences of lattice parameter, bulk modulus and fundamental band gap for each alloy system exhibit nonlinearity. The atomic and orbital origin of different electronic states in the band structure of each compound are explored from its density of states (DOS). The microscopic origin of band gap bowing for each of the alloy systems is explored in terms of volume deformation, charge exchange and structural relaxation. The chemical bonds between the constituent atoms in each compound are found as ionic in nature. Optical properties of each specimen are calculated from its computed spectra of dielectric function, refractive index, extinction coefficient, normal incidence reflectivity, optical conductivity, optical absorption and energy loss function. Several calculated results have been compared with available experimental and other theoretical data.

  6. Mare Chromium Crater

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    This crater, located in Mare Chromium, shows evidence of exterior modification, with little interior modification. While the rim is still visible, the ejecta blanket has been removed or covered. There is some material at the bottom of the crater, but the interior retains the bowl shape from the initial formation of the crater.

    Image information: VIS instrument. Latitude -34.4, Longitude 174.4 East (185.6 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  7. Ultrafast optical modification of exchange interactions in iron oxides

    NASA Astrophysics Data System (ADS)

    Mikhaylovskiy, R. V.; Hendry, E.; Secchi, A.; Mentink, J. H.; Eckstein, M.; Wu, A.; Pisarev, R. V.; Kruglyak, V. V.; Katsnelson, M. I.; Rasing, Th.; Kimel, A. V.

    2015-09-01

    Ultrafast non-thermal manipulation of magnetization by light relies on either indirect coupling of the electric field component of the light with spins via spin-orbit interaction or direct coupling between the magnetic field component and spins. Here we propose a scenario for coupling between the electric field of light and spins via optical modification of the exchange interaction, one of the strongest quantum effects with strength of 103 Tesla. We demonstrate that this isotropic opto-magnetic effect, which can be called inverse magneto-refraction, is allowed in a material of any symmetry. Its existence is corroborated by the experimental observation of terahertz emission by spin resonances optically excited in a broad class of iron oxides with a canted spin configuration. From its strength we estimate that a sub-picosecond modification of the exchange interaction by laser pulses with fluence of about 1 mJ cm-2 acts as a pulsed effective magnetic field of 0.01 Tesla.

  8. On small beams with large topological charge: II. Photons, electrons and gravitational waves

    NASA Astrophysics Data System (ADS)

    Krenn, Mario; Zeilinger, Anton

    2018-06-01

    Beams of light with a large topological charge significantly change their spatial structure when they are focused strongly. Physically, it can be explained by an emerging electromagnetic field component in the direction of propagation, which is neglected in the simplified scalar wave picture in optics. Here we ask: is this a specific photonic behavior, or can similar phenomena also be predicted for other species of particles? We show that the same modification of the spatial structure exists for relativistic electrons as well as for focused gravitational waves. However, this is for different physical reasons: for electrons, which are described by the Dirac equation, the spatial structure changes due to a spin–orbit coupling in the relativistic regime. In gravitational waves described with linearized general relativity, the curvature of space–time between the transverse and propagation direction leads to the modification of the spatial structure. Thus, this universal phenomenon exists for both massive and massless elementary particles with spin 1/2, 1 and 2. It would be very interesting whether other types of particles such as composite systems (neutrons or C60) or neutrinos show a similar behavior and how this phenomenon can be explained in a unified physical way.

  9. The Space Shuttle orbiter payload retention systems

    NASA Technical Reports Server (NTRS)

    Hardee, J. H.

    1982-01-01

    Payloads are secured in the orbiter payload bay by the payload retention system or are equipped with their own unique retention systems. The orbiter payload retention mechanisms provide structural attachments for each payload by using four or five attachment points to secure the payload within the orbiter payload bay during all phases of the orbiter mission. The payload retention system (PRS) is an electromechanical system that provides standarized payload carrier attachment fittings to accommodate up to five payloads for each orbiter flight. The mechanisms are able to function under either l-g or zero-g conditions. Payload berthing or deberthing on orbit is accomplished by utilizing the remote manipulator system (RMS). The retention mechanisms provide the capability for either vertical or horizontal payload installation or removal. The payload support points are selected to minimize point torsional, bending, and radial loads imparted to the payloads. In addition to the remotely controlled latching system, the passive system used for nondeployable payloads performs the same function as the RMS except it provides fixed attachments to the orbiter.

  10. Origin of doping-induced suppression and reemergence of magnetism in LaFeAsO 1 - x H x

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Moon, Chang-Youn; Park, Hyowon; Haule, Kristjan

    We investigate the evolution of magnetic properties as a function of hydrogen doping in the iron-based superconductor LaFeAsO 1-xH x using dynamical mean-field theory combined with density-functional theory. We find that two independent consequences of doping, namely the increase of the electron occupation and the structural modification, have the opposite effects on the strength of electron correlation and magnetism, resulting in the minimum of the calculated magnetic moment around the intermediate doping level as a function of x. Our result provides a natural explanation for the recent, puzzling experimental discovery of two separated antiferromagnetic phases at low and high dopingmore » limits. Furthermore, the increase of the orbital occupation and correlation strength with doping results in reduced orbital polarization of d(xz/yz) orbitals and an enhanced role of the d(xy) orbital in the magnetism at high doping levels, and their possible implications on the superconductivity are discussed in line with the essential role of the magnetism.« less

  11. Stability of Multi-Planet Systems Orbiting in the Alpha Centauri AB System

    NASA Astrophysics Data System (ADS)

    Lissauer, Jack

    2018-04-01

    We evaluate how closely-spaced planetary orbits in multiple planet systems can be and still survive for billion-year timescales within the alpha Centauri AB system. Although individual planets on nearly circular, coplanar orbits can survive throughout the habitable zones of both stars, perturbations from the companion star imply that the spacing of such planets in multi-planet systems must be significantly larger than the spacing of similar systems orbiting single stars in order to be long-lived. Because the binary companion induces a forced eccentricity upon circumstellar planets, stable orbits with small initial eccentricities aligned with the binary orbit are possible to slightly larger initial semimajor axes than are initially circular orbits. Initial eccentricities close to the appropriate forced eccentricity can have a much larger affect on how closely planetary orbits can be spaced, on how many planets may remain in the habitable zones, although the required spacing remains significantly higher than for planets orbiting single stars.

  12. Achieving a Launch on Demand Capability

    NASA Astrophysics Data System (ADS)

    Greenberg, Joel S.

    2002-01-01

    The ability to place payloads [satellites] into orbit as and when required, often referred to as launch on demand, continues to be an elusive and yet largely unfulfilled goal. But what is the value of achieving launch on demand [LOD], and what metrics are appropriate? Achievement of a desired level of LOD capability must consider transportation system thruput, alternative transportation systems that comprise the transportation architecture, transportation demand, reliability and failure recovery characteristics of the alternatives, schedule guarantees, launch delays, payload integration schedules, procurement policies, and other factors. Measures of LOD capability should relate to the objective of the transportation architecture: the placement of payloads into orbit as and when required. Launch on demand capability must be defined in probabilistic terms such as the probability of not incurring a delay in excess of T when it is determined that it is necessary to place a payload into orbit. Three specific aspects of launch on demand are considered: [1] the ability to recover from adversity [i.e., a launch failure] and to keep up with the steady-state demand for placing satellites into orbit [this has been referred to as operability and resiliency], [2] the ability to respond to the requirement to launch a satellite when the need arises unexpectedly either because of an unexpected [random] on-orbit satellite failure that requires replacement or because of the sudden recognition of an unanticipated requirement, and [3] the ability to recover from adversity [i.e., a launch failure] during the placement of a constellation into orbit. The objective of this paper is to outline a formal approach for analyzing alternative transportation architectures in terms of their ability to provide a LOD capability. The economic aspect of LOD is developed by establishing a relationship between scheduling and the elimination of on-orbit spares while achieving the desired level of on-orbit availability. Results of an analysis are presented. The implications of launch on demand are addressed for each of the above three situations and related architecture performance metrics and computer simulation models are described that may be used to evaluate the implications of architecture and policy changes in terms of LOD requirements. The models and metrics are aimed at providing answers to such questions as: How well does a specified space transportation architecture respond to satellite launch demand and changes thereto? How well does a normally functioning and apparently architecture respond to unanticipated needs? What is the effect of a modification to the architecture on its ability to respond to satellite launch demand, including responding to unanticipated needs? What is the cost of the architecture [including facilities, operations, inventory, and satellites]? What is the sensitivity of overall architecture effectiveness and cost to various transportation system delays? What is the effect of adding [or eliminating] a launch vehicle or family of vehicles to [from] the architecture on its effectiveness and cost? What is the value of improving launch vehicle and satellite compatibility and what are the effects on probability of delay statistics and cost of designing for multi-launch vehicle compatibility

  13. Near Earth Network (NEN) CubeSat Communications

    NASA Technical Reports Server (NTRS)

    Schaire, Scott

    2017-01-01

    The NASA Near Earth Network (NEN) consists of globally distributed tracking stations, including NASA, commercial, and partner ground stations, that are strategically located to maximize the coverage provided to a variety of orbital and suborbital missions, including those in LEO (Low Earth Orbit), GEO (Geosynchronous Earth Orbit), HEO (Highly Elliptical Orbit), lunar and L1-L2 orbits. The NEN's future mission set includes and will continue to include CubeSat missions. The first NEN-supported CubeSat mission will be the Cubesat Proximity Operations Demonstration (CPOD) launching into LEO in 2017. The majority of the CubeSat missions destined to fly on EM-1, launching in late 2018, many in a lunar orbit, will communicate with ground-based stations via X-band and will utilize the NASA Jet Propulsion Laboratory (JPL)-developed IRIS (Satellite Communication for Air Traffic Management) radio. The NEN recognizes the important role CubeSats are beginning to play in carrying out NASAs mission and is therefore investigating the modifications needed to provide IRIS radio compatibility. With modification, the NEN could potentially expand support to the EM-1 (Exploration Mission-1) lunar CubeSats. The NEN could begin providing significant coverage to lunar CubeSat missions utilizing three to four of the NEN's mid-latitude sites. This coverage would supplement coverage provided by the JPL Deep Space Network (DSN). The NEN, with smaller apertures than DSN, provides the benefit of a larger beamwidth that could be beneficial in the event of uncertain ephemeris data. In order to realize these benefits the NEN would need to upgrade stations targeted based on coverage ability and current configuration ease of upgrade, to ensure compatibility with the IRIS radio. In addition, the NEN is working with CubeSat radio developers to ensure NEN compatibility with alternative CubeSat radios for Lunar and L1-L2 CubeSats. The NEN has provided NEN compatibility requirements to several radio developers who are developing radios that offer lower cost and, in some cases, more capabilities with fewer constraints. The NEN is ready to begin supporting CubeSat missions. The NEN is considering network upgrades to broaden the types of CubeSat missions that can be supported and is supporting both the CubeSat community and radio developers to ensure future CubeSat missions have multiple options when choosing a network for their communications support.

  14. STS-68 747 SCA Ferry Flight Takeoff for Delivery to Kennedy Space Center, Florida

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The Space Shuttle Columbia, atop NASA's 747 Shuttle Carrier Aircraft (SCA), taking off for the Kennedy Space Center shortly after its landing on 12 October 1994, at Edwards, California, to complete mission STS-68. Columbia was being ferried from the Kennedy Space Center, Florida, to Air Force Plant 42, Palmdale, California, where it will undergo six months of inspections, modifications, and systems upgrades. The STS-68 11-day mission was devoted to radar imaging of Earth's geological features with the Space Radar Laboratory. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain inside the payload bay throughout the mission. They are then removed after the Space Shuttle returns to Earth and can be reused on future flights. Some of these orbital laboratories, like the Spacelab, provide facilities for several specialists to conduct experiments in such fields as medicine, astronomy, and materials manufacturing. Some types of satellites deployed by Space Shuttles include those involved in environmental and resources protection, astronomy, weather forecasting, navigation, oceanographic studies, and other scientific fields. The Space Shuttles can also launch spacecraft into orbits higher than the Shuttle's altitude limit through the use of Inertial Upper Stage (IUS) propulsion units. After release from the Space Shuttle payload bay, the IUS is ignited to carry the spacecraft into deep space. The Space Shuttles are also being used to carry elements of the International Space Station into space where they are assembled in orbit. The Space Shuttles were built by Rockwell International's Space Transportation Systems Division, Downey, California. Rockwell's Rocketdyne Division (now part of Boeing) builds the three main engines, and Thiokol, Brigham City, Utah, makes the solid rocket booster motors. Martin Marietta Corporation (now Lockheed Martin), New Orleans, Louisiana, makes the external tanks. Each orbiter (Space Shuttle) is 121 feet long, has a wingspan of 78 feet, and a height of 57 feet. The Space Shuttle is approximately the size of a DC-9 commercial airliner and can carry a payload of 65,000 pounds into orbit. The payload bay is 60 feet long and 15 feet in diameter. Each main engine is capable of producing a sea level thrust of 375,000 pounds and a vacuum (orbital) thrust of 470,000 pounds. The engines burn a mixture of liquid oxygen and liquid hydrogen. In orbit, the Space Shuttles circle the earth at a speed of 17,500 miles per hour with each orbit taking about 90 minutes. A Space Shuttle crew sees a sunrise or sunset every 45 minutes. When Space Shuttle flights began in April 1981, Dryden Flight Research Center, Edwards, California, was the primary landing site for the Shuttles. Now Kennedy Space Center, Florida, is the primary landing site with Dryden remaining as the principal alternate landing site.

  15. The SMARTSat redesign study

    NASA Technical Reports Server (NTRS)

    Lu, Richard; Chan, Jeffrey

    1994-01-01

    The original design of the Student Mentored Advanced Research and Technology Satellite (SMARTSat) began in January of 1994. The mission adhered to the guidelines and constraints set forth by the Student Explorer Demonstration Initiative Proposal, which was sponsored by the Universities Space Research Association. This report represents a redesign of that original concept. The main differences include a higher orbit and a three axis stabilization system. Of course, these changes imparted significant effects upon the other subsystems. Outlined in this document are those modifications and it offers some new analyses as well. For each subsystem there is a brief description, followed by relevant design assumptions, a summary of conclusions, and finally all pertinent supporting data and graphs. Towards the end of the report. the important issue of cost is addressed as well. Whenever possible, parametric analyses were made.

  16. Shuttle program. MCC Level C formulation requirements: Entry guidance and entry autopilot

    NASA Technical Reports Server (NTRS)

    Harpold, J. C.; Hill, O.

    1980-01-01

    A set of preliminary entry guidance and autopilot software formulations is presented for use in the Mission Control Center (MCC) entry processor. These software formulations meet all level B requirements. Revision 2 incorporates the modifications required to functionally simulate optimal TAEM targeting capability (OTT). Implementation of this logic in the MCC must be coordinated with flight software OTT implementation and MCC TAEM guidance OTT. The entry guidance logic is based on the Orbiter avionics entry guidance software. This MCC requirements document contains a definition of coordinate systems, a list of parameter definitions for the software formulations, a description of the entry guidance detailed formulation requirements, a description of the detailed autopilot formulation requirements, a description of the targeting routine, and a set of formulation flow charts.

  17. TOPEX/Poseidon precision orbit determination production and expert system

    NASA Technical Reports Server (NTRS)

    Putney, Barbara; Zelensky, Nikita; Klosko, Steven

    1993-01-01

    TOPEX/Poseidon (T/P) is a joint mission between NASA and the Centre National d'Etudes Spatiales (CNES), the French Space Agency. The TOPEX/Poseidon Precision Orbit Determination Production System (PODPS) was developed at Goddard Space Flight Center (NASA/GSFC) to produce the absolute orbital reference required to support the fundamental ocean science goals of this satellite altimeter mission within NASA. The orbital trajectory for T/P is required to have a RMS accuracy of 13 centimeters in its radial component. This requirement is based on the effective use of the satellite altimetry for the isolation of absolute long-wavelength ocean topography important for monitoring global changes in the ocean circulation system. This orbit modeling requirement is at an unprecedented accuracy level for this type of satellite. In order to routinely produce and evaluate these orbits, GSFC has developed a production and supporting expert system. The PODPS is a menu driven system allowing routine importation and processing of tracking data for orbit determination, and an evaluation of the quality of the orbit so produced through a progressive series of tests. Phase 1 of the expert system grades the orbit and displays test results. Later phases undergoing implementation, will prescribe corrective actions when unsatisfactory results are seen. This paper describes the design and implementation of this orbit determination production system and the basis for its orbit accuracy assessment within the expert system.

  18. Two designs for an orbital transfer vehicle

    NASA Technical Reports Server (NTRS)

    Davis, Richard; Duquette, Miles; Fredrick, Rebecca; Schumacher, Daniel; Somers, Schaeffer; Stafira, Stanley; Williams, James; Zelinka, Mark

    1988-01-01

    The Orbital Transfer Vehicle (OTV) and systems were researched in the following areas: avionics, crew systems, electrical power systems, environmental control/life support systems, navigation and orbital maneuvers, propulsion systems, reaction control systems (RCS), servicing systems, and structures.

  19. Solid Propulsion De-Orbiting and Re-Orbiting

    NASA Astrophysics Data System (ADS)

    Schonenborg, R. A. C.; Schoyer, H. F. R.

    2009-03-01

    With many "innovative" de-orbit systems (e.g. tethers, aero breaking, etc.) and with natural de-orbit, the place of impact of unburned spacecraft debris on Earth can not be determined accurately. The idea that satellites burn up completely upon re-entry is a common misunderstanding. To the best of our knowledge only rocket motors are capable of delivering an impulse that is high enough, to conduct a de-orbit procedure swiftly, hence to de-orbit at a specific moment that allows to predict the impact point of unburned spacecraft debris accurately in remote areas. In addition, swift de-orbiting will reduce the on-orbit time of the 'dead' satellite, which reduces the chance of the dead satellite being hit by other dead or active satellites, while spiralling down to Earth during a slow, 25 year, or more, natural de-orbit process. Furthermore the reduced on-orbit time reduces the chance that spacecraft batteries, propellant tanks or other components blow up and also reduces the time that the object requires tracking from Earth.The use of solid propellant for the de-orbiting of spacecraft is feasible. The main advantages of a solid propellant based system are the relatively high thrust and the facts that the system can be made autonomous quite easily and that the system can be very reliable. The latter is especially desirable when one wants to de-orbit old or 'dead' satellites that might not be able to rely anymore on their primary systems. The disadvantage however, is the addition of an extra system to the spacecraft as well as a (small) mass penalty. [1]This paper describes the above mentioned system and shows as well, why such a system can also be used to re-orbit spacecraft in GEO, at the end of their life to a graveyard orbit.Additionally the system is theoretically compared to an existing system, of which performance data is available.A swift market analysis is performed as well.

  20. Pioneer Mars surface penetrator mission. Mission analysis and orbiter design

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The Mars Surface Penetrator mission was designed to provide a capability for multiple and diverse subsurface science measurements at a low cost. Equipment required to adapt the Pioneer Venus spacecraft for the Mars mission is described showing minor modifications to hardware. Analysis and design topics which are similar and/or identical to the Pioneer Venus program are briefly discussed.

  1. Tevatron optics with magnet moves for Roman pots at CDF

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    John A. Johnstone

    2001-08-16

    CDF would like to install high precision track detectors. There is ample room on A-sector side, but space needs to be created at B11. The favored plan is to shove the first 3 B11 dipoles inwards toward the IP by 2.274 m. This would require removal of the inert Q1 quadrupole and its spool plus an extensive number of other mechanical and cryogenic modifications. The orbit distortion these modifications introduce would then be compensated by shifting the six B16 and B17 dipoles outwards by about half that amount. Space for this dipole move could be generated by replacing the 72more » inch spool at B18 with a short 43 inch spool, and removing the 16.5 inch spacer after B17-5. The above scheme certainly recloses the orbit, and doesn't require the detector to move. However, by moving the B16 and B17 dipoles, the B17 and B18 arc quadrupoles also get shifted downstream--B17 by 1.115 m, and B18 by 0.696 m. Longitudinal movements of arc quads by such large fractions of their magnetic lengths will clearly impact the overall machine optics.« less

  2. One of NASA's Two Modified Boeing 747 Shuttle Carrier (SCA) Aircraft in Flight over NASA Dryden Flig

    NASA Technical Reports Server (NTRS)

    1999-01-01

    One of NASA's Boeing 747 Shuttle Carrier Aircraft flies over the Dryden Flight Research Center main building at Edwards Air Force Base, Edwards, California, in May 1999. NASA uses two modified Boeing 747 jetliners, originally manufactured for commercial use, as Space Shuttle Carrier Aircraft (SCA). One is a 747-100 model, while the other is designated a 747-100SR (short range). The two aircraft are identical in appearance and in their performance as Shuttle Carrier Aircraft. The 747 series of aircraft are four-engine intercontinental-range swept-wing 'jumbo jets' that entered commercial service in 1969. The SCAs are used to ferry space shuttle orbiters from landing sites back to the launch complex at the Kennedy Space Center, and also to and from other locations too distant for the orbiters to be delivered by ground transportation. The orbiters are placed atop the SCAs by Mate-Demate Devices, large gantry-like structures which hoist the orbiters off the ground for post-flight servicing, and then mate them with the SCAs for ferry flights. Features which distinguish the two SCAs from standard 747 jetliners are: o Three struts, with associated interior structural strengthening, protruding from the top of the fuselage (two aft, one forward) on which the orbiter is attached o Two additional vertical stabilizers, one on each end of the standard horizontal stabilizer, to enhance directional stability o Removal of all interior furnishings and equipment aft of the forward No. 1 doors o Instrumentation used by SCA flight crews and engineers to monitor orbiter electrical loads during the ferry flights and also during pre- and post-ferry flight operations. The two SCAs are under the operational control of NASA's Johnson Space Center, Houston, Tex. NASA 905 NASA 905 was the first SCA. It was obtained from American Airlines in 1974. Shortly after it was accepted by NASA it was flown in a series of wake vortex research flights at the Dryden Flight Research Center in a study to seek ways of reducing turbulence produced by large aircraft. Pilots flying as much as several miles behind large aircraft have encountered wake turbulence that have caused control problems. The NASA study helped the Federal Aviation Administration modify flight procedures for commercial aircraft during airport approaches and departures. Following the wake vortex studies, NASA 905 was modified by Boeing to its present SCA configuration and the aircraft was returned to Dryden for its role in the 1977 Space Shuttle Approach and Landing Tests (ALT). This series of eight captive and five free flights with the orbiter prototype Enterprise, in addition to ground taxi tests, validated the aircraft's performance as an SCA, in addition to verifying the glide and landing characteristics of the orbiter configuration -- paving the way for orbital flights. A flight crew escape system, consisting of an exit tunnel extending from the flight deck to a hatch in the bottom of the fuselage, was installed during the modifications. The system also included a pyrotechnic system to activate the hatch release and cabin window release mechanisms. The flight crew escape system was removed from the NASA 905 following the successful completion of the ALT program. NASA 905 was the only SCA used by the space shuttle program until November 1990, when NASA 911 was delivered as an SCA. Along with ferrying Enterprise and the flight-rated orbiters between the launch and landing sites and other locations, NASA 905 also ferried Enterprise to Europe for display in England and at the Paris Air Show. NASA 911 The second SCA is designated NASA 911. It was obtained by NASA from Japan Airlines (JAL) in 1989. It was also modified by Boeing Corporation. It was delivered to NASA 20 November 1990.

  3. Long-term Stability of Tightly Packed Multi-planet Systems in Prograde, Coplanar, Circumstellar Orbits within the α Centauri AB System

    NASA Astrophysics Data System (ADS)

    Quarles, B.; Lissauer, Jack J.

    2018-03-01

    We perform long-term simulations, up to ten billion years, of closely spaced configurations of 2–6 planets, each as massive as the Earth, traveling on nested orbits about either stellar component in α Centauri AB. The innermost planet initially orbits at either the inner edge of its star’s empirical habitable zone (HZ) or the inner edge of its star’s conservative HZ. Although individual planets on low inclination, low eccentricity, orbits can survive throughout the HZs of both stars, perturbations from the companion star require that the minimum spacing of planets in multi-planet systems within the HZs of each star must be significantly larger than the spacing of similar multi-planet systems orbiting single stars in order to be long-lived. The binary companion induces a forced eccentricity upon the orbits of planets in orbit around either star. Planets on appropriately phased circumstellar orbits with initial eccentricities equal to their forced eccentricities can survive on more closely spaced orbits than those with initially circular orbits, although the required spacing remains higher than for planets orbiting single stars. A total of up to nine planets on nested prograde orbits can survive for the current age of the system within the empirical HZs of the two stars, with five of these orbiting α Centauri B and four orbiting α Centauri A.

  4. Space Shuttle Orbiter auxiliary power unit status

    NASA Technical Reports Server (NTRS)

    Reck, M.; Loken, G.; Horton, J.; Lukens, W.; Scott, W.; Baughman, J.; Bauch, T.

    1991-01-01

    An overview of the United States Space Shuttle Orbiter APU, which provides power to the Orbiter vehicle hydraulic system, is presented. Three complete APU systems, each with its own separate fuel system, supply power to three dedicated hydraulic systems. These in turn provide power to all Orbiter vehicle critical flight functions including launch, orbit, reentry, and landing. The basic APU logic diagram is presented. The APU includes a hydrazine-powered turbine that drives a hydraulic pump and various accessories through a high-speed gearbox. The APU also features a sophisticated thermal management system designed to ensure safe and reliable operation in the various launch, orbit, reentry, and landing environments.

  5. Communications satellites in non-geostationary orbits

    NASA Technical Reports Server (NTRS)

    Price, Kent M.; Doong, Wen; Nguyen, Tuan Q.; Turner, Andrew E.; Weyandt, Charles

    1988-01-01

    The design of a satellite communications system in an orbit lower than GEO is described. Two sun-synchronous orbits which lie in the equatorial plane have been selected: (1) the apogee at constant time-of-day equatorial orbit, a highly eccentric orbit with five revolutions per day, which allows 77-135 percent more satellite mass to be placed in orbit than for GEO; and (2) the sun-synchronous 12-hour equatorial orbit, a circular orbit with two revolutions per day, which allows 23-29 percent more mass. The results of a life cycle economic analysis illustrate that nongeostationary satellite systems could be competitive with geostationary satellite systems.

  6. Spacecraft transfer trajectory design exploiting resonant orbits in multi-body environments

    NASA Astrophysics Data System (ADS)

    Vaquero Escribano, Tatiana Mar

    Historically, resonant orbits have been employed in mission design for multiple planetary flyby trajectories and, more recently, as a source of long-term orbital stability. For instance, in support of a mission concept in NASA's Outer Planets Program, the Jupiter Europa Orbiter spacecraft is designed to encounter two different resonances with Europa during the 'endgame' phase, leading to Europa orbit insertion on the final pass. In 2011, the Interstellar Boundary Explorer spacecraft was inserted into a stable out-of-plane lunar-resonant orbit, the first of this type for a spacecraft in a long-term Earth orbit. However, resonant orbits have not yet been significantly explored as transfer mechanisms between non-resonant orbits in multi-body systems. This research effort focuses on incorporating resonant orbits into the design process to potentially enable the construction of more efficient or even novel transfer scenarios. Thus, the goals in this investigation are twofold: i) to expand the orbit architecture in multi-body environments by cataloging families of resonant orbits, and ii) to assess the role of such families in the design of transfer trajectories with specific patterns and itineraries. The benefits and advantages of employing resonant orbits in the design process are demonstrated through a variety of astrodynamics applications in several multi-body systems. In the Earth-Moon system, locally optimal transfer trajectories from low Earth orbit to selected libration point orbits are designed by leveraging conic arcs and invariant manifolds associated with resonant orbits. Resonant manifolds in the Earth-Moon system offer trajectories that tour the entire space within reasonable time intervals, facilitating the design of libration point orbit tours as well as Earth-Moon cyclers. In the Saturnian system, natural transitions between resonant and libration point orbits are sought and the problem of accessing Hyperion from orbits that are resonant with Titan is also examined. To add versatility to the proposed design method, a system translation technique enables the straightforward transition of solutions from the Earth-Moon system to any Sun-planet or planet-moon three-body system. The circular restricted three-body problem serves as a basis to quickly generate solutions that meet specific requirements, but candidate transfer trajectories are then transitioned to an ephemeris model for validation.

  7. Polar Crater Deposits as a Probe for Ancient Climate Change on Mars

    NASA Astrophysics Data System (ADS)

    Armstrong, John

    2006-10-01

    Dynamical studies of the Martian orbit suggest a planet that has undergone extreme orbital change. How has this affected the planet's climate? Is there a record of this orbit-induced climate change written in the geology that is expressed on the surface? If so, such a record would provide insight into Mars' climate history, and shed light on the types of habitats for life that may have existed in the past. We are exploring how the current seasonal polar caps interact with polar craters in an effort to identify modification that can be linked to the proximity of the polar cap. Ice deposits within the craters are evident in both thermal spectra and imagery from Mars orbiters. We have linked these ice deposits to morphological deposits that can be identified in other craters that are further from the pole. These deposits may act as a probe of the variations suggested by orbital calculations, as well as provide an indicator of the extent of the sub-surface ice table. We will present preliminary results from a sample of northern craters, and explain how this can be extended to southern craters, and possibly mid-latitude craters, in an effort to understand more fully the martian climate through time.

  8. Universal functions of nuclear proximity potential for Skyrme nucleus-nucleus interaction in a semiclassical approach

    NASA Astrophysics Data System (ADS)

    Gupta, Raj K.; Singh, Dalip; Kumar, Raj; Greiner, Walter

    2009-07-01

    The universal function of the nuclear proximity potential is obtained for the Skyrme nucleus-nucleus interaction in the semiclassical extended Thomas-Fermi (ETF) approach. This is obtained as a sum of the spin-orbit-density-independent and spin-orbit-density-dependent parts of the Hamiltonian density, since the two terms behave differently, the spin-orbit-density-independent part mainly attractive and the spin-orbit-density-dependent part mainly repulsive. The semiclassical expansions of kinetic energy density and spin-orbit density are allowed up to second order, and the two-parameter Fermi density, with its parameters fitted to experiments, is used for the nuclear density. The universal functions or the resulting nuclear proximity potential reproduce the 'exact' Skyrme nucleus-nucleus interaction potential in the semiclassical approach, within less than ~1 MeV of difference, both at the maximum attraction and in the surface region. An application of the resulting interaction potential to fusion excitation functions shows clearly that the parameterized universal functions of nuclear proximity potential substitute completely the 'exact' potential in the Skyrme energy density formalism based on the semiclassical ETF method, including also the modifications of interaction barriers at sub-barrier energies in terms of modifying the constants of the universal functions.

  9. Bottom-up synthesis of WS2 nanosheets with synchronous surface modification for imaging guided tumor regression.

    PubMed

    Wang, Shige; Zhao, Jiulong; Yang, Hailun; Wu, Chenyao; Hu, Fei; Chang, Haizhou; Li, Guixiang; Ma, Dan; Zou, Duowu; Huang, Mingxian

    2017-08-01

    Two-dimensional transition metal dichalcogenides (TMDs) have been receiving great attention as NIR photothermal transducing agent in tumor photothermal therapy. Keeping in mind the low efficiency of the conventional top-down exfoliated 2D TMDs and the complexity of their surface modifications, we herein proposed a bottom-up strategy for the one-pot hydrothermal and controlled synthesis of surface polyvinyl pyrrolidone (PVP) modified WS 2 nanosheets. The material design was based on the chelating-coordinating effect between the lone pair electrons of oxygen of PVP carbonyl group and the unoccupied orbital (5d orbitals) of tungsten. The WS 2 nanosheets with synchronous surface PVP grafting showed an excellent photothermal conversion performance, while the surface anchored PVP guaranteed its colloidal stability. Moreover, the strong X-ray attenuation ability and near-infrared (NIR) absorbance of WS 2 -PVP 360kDa enabled the sensitive in vitro and in vivo computed tomography and photoacoustic imaging. The WS 2 -PVP 360kDa nanosheets were biocompatible and exhibited promising in vitro and in vivo anti-cancer efficacy. Findings in this report may greatly promote the design of colloidal stable and biocompatible 2D TMDs and their future clinical translations. A bottom-up strategy for the one-pot and controlled synthesis of surface polyvinyl pyrrolidone (PVP) modified WS 2 nanosheets was proposed for the first time. By hydrothermally treating the mixture solution of tetrathiotungstate and PVP, Owing to the chelating-coordinating effect between the lone pair electrons of oxygen of PVP carbonyl group and the unoccupied orbital (5d orbitals) of tungsten, PVP was synchronously graphed on WS 2 -PVP nanosheets surface. The formed WS 2 -PVP nanosheets were colloidal stable, biocompatible, and exhibited promising computed tomography, photoacoustic imaging and tumor photothermal therapy efficacy both in vitro and in vivo. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  10. International Space Station Common Cabin Air Assembly Water Separator On-Orbit Operation, Failure, and Redesign

    NASA Technical Reports Server (NTRS)

    Balistreri, Steven F., Jr.; Shaw, Laura A.; Laliberte, Yvon

    2010-01-01

    The ability to control the temperature and humidity of an environment or habitat is critical for human survival. These factors are important to maintaining human health and comfort, as well as maintaining mechanical and electrical equipment in good working order to support the human and to accomplish mission objectives. The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin air is controlled by the Common Cabin Air Assembly (CCAA). The CCAA consists of a fan, a condensing heat exchanger (CHX), an air/water separator, temperature and liquid sensors, and electrical controlling hardware and software. The Water Separator (WS) pulls in air and water from the CHX, and centrifugally separates the mixture, sending the water to the condensate bus and the air back into the CHX outlet airstream. Two distinct early failures of the CCAA Water Separator in the Quest Airlock forced operational changes and brought about the re-design of the Water Separator to improve the useful life via modification kits. The on-orbit operational environment of the Airlock presented challenges that were not foreseen with the original design of the Water Separator. Operational changes were instituted to prolong the life of the third installed WS, while waiting for newly designed Water Separators to be delivered on-orbit. The modification kit design involved several different components of the Water Separator, including the innovative use of a fabrication technique to build the impellers used in Water Separators out of titanium instead of aluminum. The technique allowed for the cost effective production of the low quantity build. This paper will describe the failures of the Water Separators in the Quest Airlock, the operational constraints that were implemented to prolong the life of the installed Water Separators throughout the USOS, and the innovative re-design of the CCAA Water Separator.

  11. First flight test results of the Simplified Aid For EVA Rescue (SAFER) propulsion unit

    NASA Technical Reports Server (NTRS)

    Meade, Carl J.

    1995-01-01

    The Simplified Aid for EVA Rescue (SAFER) is a small, self-contained, propulsive-backpack system that provides free-flying mobility for an astronaut engaged in a space walk, also known as extravehicular activity (EVA.) SAFER contains no redundant systems and is intended for contingency use only. In essence, it is a small, simplified version of the Manned Maneuvering Unit (MMU) last flown aboard the Space Shuttle in 1985. The operational SAFER unit will only be used to return an adrift EVA astronaut to the spacecraft. Currently, if an EVA crew member inadvertently becomes separated from the Space Shuttle, the Orbiter will maneuver to within the crew member's reach envelope, allowing the astronaut to regain contact with the Orbiter. However, with the advent of operations aboard the Russian MIR Space Station and the International Space Station, the Space Shuttle will not be available to effect a timely rescue. Under these conditions, a SAFER unit would be worn by each EVA crew member. Flight test of the pre-production model of SAFER occurred in September 1994. The crew of Space Shuttle Mission STS-64 flew a 6.9 hour test flight which included performance, flying qualities, systems, and operational utility evaluations. We found that the unit offers adequate propellant and control authority to stabilize and enable the return of a tumbling/separating crew member. With certain modifications, production model of SAFER can provide self-rescue capability to a separated crew member. This paper will present the program background, explain the flight test results and provide some insight into the complex operations of flight test in space.

  12. Mars’ Growth Stunted by an Early Giant Planet Instability

    NASA Astrophysics Data System (ADS)

    Clement, Matthew; Kaib, Nathan A.; Raymond, Sean N.; Walsh, Kevin J.

    2017-10-01

    Many dynamical aspects of the solar system can be explained by the outer planets experiencing a period of orbital instability. Though often correlated with a perceived delayed spike in the lunar cratering record known as the Late Heavy Bombardment (LHB), recent work suggests that this event may have occurred during the epoch of terrestrial planet formation. Though current simulations of terrestrial accretion can reproduce many observed qualities of the solar system, replicating the small mass of Mars requires modification to standard planet formation models. Here we use direct numerical simulations to show that an early instability in the outer solar system regularly yields properly sized Mars analogues. In 80% of simulations, we produce a Mars of the appropriate mass. Our most successful outcomes occur when the terrestrial planets evolve 10 million years (Myr), and accrete several Mars sized embryos in the Mars forming region before the instability takes place. Mars is left behind as a stranded embryo, while the remainder of these bodies are either ejected from the system or scattered towards the inner solar system where they deliver water to Earth. An early giant planet instability can thus replicate both the inner and outer solar system in a single model.

  13. The Solar Poynting-Robertson Effect On Particles Orbiting Solar System Bodies: Circular Orbits

    NASA Technical Reports Server (NTRS)

    Rubincam, David P.

    2013-01-01

    The Poynting-Robertson effect from sunlight impinging directly on a particle which orbits a Solar System body (planet, asteroid, comet) is considered from the Sun's rest frame. There appear to be no significant first-order terms in V(sub b)/c for circular orbits, where V(sub b) is the body's speed in its orbit about the Sun and c is the speed of light, when the particle's orbital semimajor axis is much smaller than the body's orbital semimajor axis about the Sun as is mainly the case in the Solar System.

  14. Structural Weight Estimation for Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Cerro, Jeff; Martinovic, Zoran; Su, Philip; Eldred, Lloyd

    2002-01-01

    This paper describes some of the work in progress to develop automated structural weight estimation procedures within the Vehicle Analysis Branch (VAB) of the NASA Langley Research Center. One task of the VAB is to perform system studies at the conceptual and early preliminary design stages on launch vehicles and in-space transportation systems. Some examples of these studies for Earth to Orbit (ETO) systems are the Future Space Transportation System [1], Orbit On Demand Vehicle [2], Venture Star [3], and the Personnel Rescue Vehicle[4]. Structural weight calculation for launch vehicle studies can exist on several levels of fidelity. Typically historically based weight equations are used in a vehicle sizing program. Many of the studies in the vehicle analysis branch have been enhanced in terms of structural weight fraction prediction by utilizing some level of off-line structural analysis to incorporate material property, load intensity, and configuration effects which may not be captured by the historical weight equations. Modification of Mass Estimating Relationships (MER's) to assess design and technology impacts on vehicle performance are necessary to prioritize design and technology development decisions. Modern CAD/CAE software, ever increasing computational power and platform independent computer programming languages such as JAVA provide new means to create greater depth of analysis tools which can be included into the conceptual design phase of launch vehicle development. Commercial framework computing environments provide easy to program techniques which coordinate and implement the flow of data in a distributed heterogeneous computing environment. It is the intent of this paper to present a process in development at NASA LaRC for enhanced structural weight estimation using this state of the art computational power.

  15. Modelling of Jupiter's Innermost Radiation Belt

    NASA Technical Reports Server (NTRS)

    Mihalov, J. D.; DeVincenzi, Donald (Technical Monitor)

    1999-01-01

    In order to understand better source and loss processes for energetic trapped protons near Jupiter, a modification of de Pater and Goertz' finite difference diffusion calculations for Jovian equatorial energetic electrons is made to apply to the case of protons inside the orbit of Metis. Explicit account is taken of energy loss in the Jovian ring. Comparison of the results is made with Galileo Probe measurements.

  16. Propulsion Options for the Global Precipitation Measurement Core Satellite

    NASA Technical Reports Server (NTRS)

    Cardiff, Eric H.; Davis, Gary T.; Folta, David C.

    2003-01-01

    This study was conducted to evaluate several propulsion system options for the Global Precipitation Measurement (GPM) core satellite. Orbital simulations showed clear benefits for the scientific data to be obtained at a constant orbital altitude rather than with a decay/reboost approach. An orbital analysis estimated the drag force on the satellite will be 1 to 12 mN during the five-year mission. Four electric propulsion systems were identified that are able to compensate for these drag forces and maintain a circular orbit. The four systems were the UK-10/TS and the NASA 8 cm ion engines, and the ESA RMT and RITl0 EVO radio-frequency ion engines. The mass, cost, and power requirements were examined for these four systems. The systems were also evaluated for the transfer time from the initial orbit of 400 x 650 km altitude orbit to a circular 400 km orbit. The transfer times were excessive, and as a consequence a dual system concept (with a hydrazine monopropellant system for the orbit transfer and electric propulsion for drag compensation) was examined. Clear mass benefits were obtained with the dual system, but cost remains an issue because of the larger power system required for the electric propulsion system. An electrodynamic tether was also evaluated in this trade study.

  17. High spin systems with orbital degeneracy.

    PubMed

    Shen, Shun-Qing; Xie, X C; Zhang, F C

    2002-01-14

    High-spin systems with orbital degeneracy are studied in the large spin limit. In the absence of Hund's coupling, the classical spin model is mapped onto disconnected orbital systems with spins up and down, respectively. The ground state of the isotropic model is an orbital valence bond state where each bond is an orbital singlet with parallel spins, and neighboring bonds interact antiferromagnetically. Possible relevance to the transition metal oxides is discussed.

  18. General view of the Orbiter Discovery in the Orbiter Processing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view of the Orbiter Discovery in the Orbiter Processing Facility at Kennedy Space Center showing the payload bay doors open exposing the heat-dissipating radiator panels located on the inside of the payload bay doors. Also in the view is the boom portion of the boom sensor system deployed as part of the return to flight procedures after STS-107 to inspect the orbiter's thermal protection system. The Remote Manipulator System, the "Canadarm", and the airlock are seen in the background of the image. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  19. Stability of Multi-Planet Systems in the Alpha Centauri System

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    2017-01-01

    We evaluate the extent of the regions within the alpha Centauri AB star system where small planets are able to orbit for billion-year timescales (Quarles & Lissauer 2016, Astron. J. 151, 111), as well as how closely-spaced planetary orbits can be within those regions in which individual planets can survive. Although individual planets on low inclination, low eccentricity, orbits can survive throughout the habitable zones of both stars, perturbations from the companion star imply that the spacing of planets in multi-planet systems within the habitable zones of each star must be significantly larger than the spacing of similar multi-planet systems orbiting single stars in order to be long-lived. Because the binary companion induces a forced eccentricity upon the orbits of planets in orbit around either star, appropriately-aligned circumstellar orbits with small initial eccentricities are stable to slightly larger initial semimajor axes than are initially circular orbits. Initial eccentricities close to forced eccentricities can have a much larger affect on how closely planetary orbits can be spaced, and therefore on how many planets may remain in the habitable zones, although the required spacing remains significantly higher than for planets orbiting single stars.

  20. Supersonic stability and control characteristics of a 0.015 scale model 69-0 of the space shuttle orbiter with forebody RSI modifications in the NASA/LaRC 4-foot UPWT (legs 1 and 2) (LA71A/B)

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Investigations are reported for the determination of aerodynamic effects of reducing the thickness of the reusable surface insulation located along the sides of the shuttle orbiter in order to allow weight reduction in the nose region. Six-component aerodynamic force and moment data were obtained at Mach numbers from 1.5 to 4.6 over an angle of attack range from about -1 deg to 28 deg. Additional tests were made over an angle of sideslip range from -6 deg to 6 deg at selected angles of attack. Test results are presented in graph and tables.

  1. Magnetochromic effect in multiferroic R In 1 ₋ x Mn x O 3 ( R = Tb , Dy)

    DOE PAGES

    Chen, P.; Holinsworth, B. S.; O'Neal, K. R.; ...

    2015-05-26

    We combined high field magnetization and magneto-optical spectroscopy to investigate spin-charge coupling in Mn-substituted rare-earth indium oxides of chemical formula RIn₁₋ xMn xO₃ (R=Tb, Dy). The edge states, on-site Mn³⁺d to d excitations, and rare-earth f-manifold excitations all track the magnetization energy due to dominant Zeeman interactions. The field-induced modifications to the rare-earth excitations are quite large because spin-orbit coupling naturally mixes spin and charge, suggesting that the next logical step in the design strategy should be to bring spin-orbit coupling onto the trigonal bipyramidal chromophore site with a 4 or 5d center.

  2. Relativistic effects in electron impact ionization from the p-orbital

    NASA Astrophysics Data System (ADS)

    Haque, A. K. F.; Uddin, M. A.; Basak, A. K.; Karim, K. R.; Saha, B. C.; Malik, F. B.

    2006-06-01

    The parameters of our recent modification of BELI formula (MBELL) [A.K.F. Haque, M.A. Uddin, A.K. Basak, K.R. Karim, B.C. Saha, Phys. Rev. A 73 (2006) 012708] are generalized in terms of the orbital quantum numbers nl to evaluate the electron impact ionization (EII) cross sections of a wide range of isoelectronic targets (H to Ne series) and incident energies. For both the open and closed p-shell targets, the present MBELL results with a single parameter set, agree nicely with the experimental cross sections. The relativistic effect of ionization in the 2p subshell of U82+ for incident energies up to 250 MeV is well accounted for by the prescribed parameters of the model.

  3. SLR tracking of GPS-35

    NASA Technical Reports Server (NTRS)

    Pavlis, Erricos C.

    1994-01-01

    An experiment was designed to launch a corner cube retroreflector array on one of the Global Positioning Satellites (GPS). The launch on Aug. 31, 1993 ushered in the era of SLR tracking of GPS spacecraft. Once the space operations group finished the check-out procedures for the new satellite, the agreed upon SLR sites were allowed to track it. The first site to acquire GPS-35 was the Russian system at Maidanak and closely after the MLRS system at McDonald Observatory, Texas. The laser tracking network is currently tracking the GPS spacecraft known as GPS-35 or PRN 5 with great success. From the NASA side there are five stations that contribute data regularly and nearly as many from the international partners. Upcoming modifications to the ground receivers will allow for a further increase in the tracking capabilities of several additional sites and add some desperately needed southern hemisphere tracking. We are analyzing the data and are comparing SLR-derived orbits to those determined on the basis of GPS radiometric data.

  4. KSC-2009-5536

    NASA Image and Video Library

    2009-10-20

    CAPE CANAVERAL, Fla. – The 327-foot-tall Ares I-X rocket clears the door of the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida, on its way to Launch Pad 39B. The move to the launch pad, known as "rollout," began at 1:39 a.m. EDT. The transfer of the pad from the Space Shuttle Program to the Constellation Program took place May 31. Modifications made to the pad include the removal of shuttle unique subsystems, such as the orbiter access arm and a section of the gaseous oxygen vent arm, along with the installation of three 600-foot lightning towers, access platforms, environmental control systems and a vehicle stabilization system. Part of the Constellation Program, the Ares I-X is the test vehicle for the Ares I. The Ares I-X flight test is targeted for Oct. 27. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo credit: NASA/Jack Pfaller

  5. KSC-2009-5913

    NASA Image and Video Library

    2009-10-27

    CAPE CANAVERAL, Fla. – At Launch Pad 39B at NASA's Kennedy Space Center in Florida, the rotating service structure has been rolled back from the Constellation Program's 327-foot-tall Ares I-X rocket, sitting atop its mobile launcher platform, during preparations for launch. The transfer of the pad from the Space Shuttle Program to the Constellation Program took place May 31. Modifications made to the pad include the removal of shuttle unique subsystems, such as the orbiter access arm and a section of the gaseous oxygen vent arm, and the installation of three 600-foot lightning towers, access platforms, environmental control systems and a vehicle stabilization system. The data returned from more than 700 sensors throughout the rocket will be used to refine the design of future launch vehicles and bring NASA one step closer to reaching its exploration goals. The Ares I-X flight test is targeted for Oct. 27. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo credit: NASA/Kim Shiflett

  6. KSC-2009-5914

    NASA Image and Video Library

    2009-10-27

    CAPE CANAVERAL, Fla. – At Launch Pad 39B at NASA's Kennedy Space Center in Florida, xenon lights illuminate the Constellation Program's 327-foot-tall Ares I-X rocket after the rotating service structure, has been retracted from around it for launch. The transfer of the pad from the Space Shuttle Program to the Constellation Program took place May 31. Modifications made to the pad include the removal of shuttle unique subsystems, such as the orbiter access arm and a section of the gaseous oxygen vent arm, and the installation of three 600-foot lightning towers, access platforms, environmental control systems and a vehicle stabilization system. The data returned from more than 700 sensors throughout the rocket will be used to refine the design of future launch vehicles and bring NASA one step closer to reaching its exploration goals. The Ares I-X flight test is targeted for Oct. 27. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo credit: NASA/Kim Shiflett

  7. KSC-2009-5917

    NASA Image and Video Library

    2009-10-27

    CAPE CANAVERAL, Fla. – Daybreak at Launch Pad 39B at NASA's Kennedy Space Center in Florida reveals the rotating service structure rolled back from around the Constellation Program's 327-foot-tall Ares I-X rocket for launch. The transfer of the pad from the Space Shuttle Program to the Constellation Program took place May 31. Modifications made to the pad include the removal of shuttle unique subsystems, such as the orbiter access arm and a section of the gaseous oxygen vent arm, and the installation of three 600-foot lightning towers, access platforms, environmental control systems and a vehicle stabilization system. The data returned from more than 700 sensors throughout the rocket will be used to refine the design of future launch vehicles and bring NASA one step closer to reaching its exploration goals. The Ares I-X flight test is targeted for Oct. 27. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo credit: NASA/Kim Shiflett

  8. Low cost Earth attitude sensor

    NASA Astrophysics Data System (ADS)

    Liberati, Fabrizio; Perrotta, Giorgio; Verzegnassi, Fulvia

    2017-11-01

    A patent-pending, low-cost, moderate performance, Earth Attitude Sensor for LEO satellites is described in this paper. The paper deals with the system concepts, the technology adopted and the simulation results. The sensor comprises three or four narrow field of view mini telescopes pointed towards the Earth edge to detect and measure the variation of the off-nadir angle of the Earth-to-black sky transition using thermopile detectors suitably placed in the foci of the optical min telescopes. The system's innovation consists in the opto-mechanical configuration adopted that is sturdy and has no moving parts being , thus, inherently reliable. In addition, with a view to reducing production costs, the sensor does without hi-rel and is instead mainly based on COTS parts suitably chosen. Besides it is flexible and can be adapted to perform attitude measurement onboard spacecraft flying in orbits other than LEO with a minimum of modifications to the basic design. At present the sensor is under development by IMT and OptoService.

  9. Detail view of the "underside" of the Orbiter Maneuvering/Reaction Control ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail view of the "underside" of the Orbiter Maneuvering/Reaction Control Systems pod looking at the two spherical propellant tanks for the Reaction Control System, and the elongated propellant tanks for the Orbiter Maneuvering System. This view was taken at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  10. Fine-Tuning the Energy Levels of a Nonfullerene Small-Molecule Acceptor to Achieve a High Short-Circuit Current and a Power Conversion Efficiency over 12% in Organic Solar Cells.

    PubMed

    Kan, Bin; Zhang, Jiangbin; Liu, Feng; Wan, Xiangjian; Li, Chenxi; Ke, Xin; Wang, Yunchuang; Feng, Huanran; Zhang, Yamin; Long, Guankui; Friend, Richard H; Bakulin, Artem A; Chen, Yongsheng

    2018-01-01

    Organic solar cell optimization requires careful balancing of current-voltage output of the materials system. Here, such optimization using ultrafast spectroscopy as a tool to optimize the material bandgap without altering ultrafast photophysics is reported. A new acceptor-donor-acceptor (A-D-A)-type small-molecule acceptor NCBDT is designed by modification of the D and A units of NFBDT. Compared to NFBDT, NCBDT exhibits upshifted highest occupied molecular orbital (HOMO) energy level mainly due to the additional octyl on the D unit and downshifted lowest unoccupied molecular orbital (LUMO) energy level due to the fluorination of A units. NCBDT has a low optical bandgap of 1.45 eV which extends the absorption range toward near-IR region, down to ≈860 nm. However, the 60 meV lowered LUMO level of NCBDT hardly changes the V oc level, and the elevation of the NCBDT HOMO does not have a substantial influence on the photophysics of the materials. Thus, for both NCBDT- and NFBDT-based systems, an unusually slow (≈400 ps) but ultimately efficient charge generation mediated by interfacial charge-pair states is observed, followed by effective charge extraction. As a result, the PBDB-T:NCBDT devices demonstrate an impressive power conversion efficiency over 12%-among the best for solution-processed organic solar cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Irradiation and Enhanced Magnetic Braking in Cataclysmic Variables

    NASA Astrophysics Data System (ADS)

    McCormick, P. J.; Frank, J.

    1998-12-01

    In previous work we have shown that irradiation driven mass transfer cycles can occur in cataclysmic variables at all orbital periods if an additional angular momentum loss mechanism is assumed. Earlier models simply postulated that the enhanced angular momentum loss was proportional to the mass transfer rate without any specific physical model. In this paper we present a simple modification of magnetic braking which seems to have the right properties to sustain irradiation driven cycles at all orbital periods. We assume that the wind mass loss from the irradiated companion consists of two parts: an intrinsic stellar wind term plus an enhancement that is proportional to the irradiation. The increase in mass flow reduces the specific angular momentum carried away by the flow but nevertheless yields an enhanced rate of magnetic braking. The secular evolution of the binary is then computed numerically with a suitably modified double polytropic code (McCormick & Frank 1998). With the above model and under certain conditions, mass transfer oscillations occur at all orbital periods.

  12. Aerothermal Analysis and Design of the Gravity Recovery and Climate Experiment (GRACE) Spacecraft

    NASA Technical Reports Server (NTRS)

    Mazanek, Daniel D.; Kumar, Renjith R.; Qu, Min; Seywald, Hans

    2000-01-01

    The Gravity Recovery and Climate Experiment (GRACE) primary mission will be performed by making measurements of the inter-satellite range change between two co-planar, low altitude near-polar orbiting satellites. Understanding the uncertainties in the disturbance environment, particularly the aerodynamic drag and torques, is critical in several mission areas. These include an accurate estimate of the spacecraft orbital lifetime, evaluation of spacecraft attitude control requirements, and estimation of the orbital maintenance maneuver frequency necessitated by differences in the drag forces acting on both satellites. The FREEMOL simulation software has been developed and utilized to analyze and suggest design modifications to the GRACE spacecraft. Aerodynamic accommodation bounding analyses were performed and worst-case envelopes were obtained for the aerodynamic torques and the differential ballistic coefficients between the leading and trailing GRACE spacecraft. These analyses demonstrate how spacecraft aerodynamic design and analysis can benefit from a better understanding of spacecraft surface accommodation properties, and the implications for mission design constraints such as formation spacing control.

  13. GRACE Mission Design: Impact of Uncertainties in Disturbance Environment and Satellite Force Models

    NASA Technical Reports Server (NTRS)

    Mazanek, Daniel D.; Kumar, Renjith R.; Seywald, Hans; Qu, Min

    2000-01-01

    The Gravity Recovery and Climate Experiment (GRACE) primary mission will be performed by making measurements of the inter-satellite range change between two co-planar, low altitude, near-polar orbiting satellites. Understanding the uncertainties in the disturbance environment, particularly the aerodynamic drag and torques, is critical in several mission areas. These include an accurate estimate of the spacecraft orbital lifetime, evaluation of spacecraft attitude control requirements, and estimation of the orbital maintenance maneuver frequency necessitated by differences in the drag forces acting on both satellites. The FREEMOL simulation software has been developed and utilized to analyze and suggest design modifications to the GRACE spacecraft. Aerodynamic accommodation bounding analyses were performed and worst-case envelopes were obtained for the aerodynamic torques and the differential ballistic coefficients between the leading and trailing GRACE spacecraft. These analyses demonstrate how spacecraft aerodynamic design and analysis can benefit from a better understanding of spacecraft surface accommodation properties, and the implications for mission design constraints such as formation spacing control.

  14. Analysis of the upper massif of the craniofacial with the radial method – practical use

    PubMed Central

    Lepich, Tomasz; Dąbek, Józefa; Stompel, Daniel; Gielecki, Jerzy S.

    2011-01-01

    Introduction The analysis of the upper massif of the craniofacial (UMC) is widely used in many fields of science. The aim of the study was to create a high resolution computer system based on a digital information record and on vector graphics, that could enable dimension measuring and evaluation of craniofacial shape using the radial method. Material and methods The study was carried out on 184 skulls, in a good state of preservation, from the early middle ages. The examined skulls were fixed into Molisson's craniostat in the author's own modification. They were directed in space towards the Frankfurt plane and photographed in frontal norm with a digital camera. The parameters describing the plane and dimensional structure of the UMC and orbits were obtained thanks to the computer analysis of the function recordings picturing the craniofacial structures and using software combining raster graphics with vector graphics. Results It was compared mean values of both orbits separately for male and female groups. In female skulls the comparison of the left and right side did not show statistically significant differences. In male group, higher values were observed for the right side. Only the circularity index presented higher values for the left side. Conclusions Computer graphics with the software used for analysing digital pictures of UMC and orbits increase the precision of measurements as well as the calculation possibilities. Recognition of the face in the post mortem examination is crucial for those working on identification in anthropology and criminology laboratories. PMID:22291834

  15. Sensitivity study of Space Station Freedom operations cost and selected user resources

    NASA Technical Reports Server (NTRS)

    Accola, Anne; Fincannon, H. J.; Williams, Gregory J.; Meier, R. Timothy

    1990-01-01

    The results of sensitivity studies performed to estimate probable ranges for four key Space Station parameters using the Space Station Freedom's Model for Estimating Space Station Operations Cost (MESSOC) are discussed. The variables examined are grouped into five main categories: logistics, crew, design, space transportation system, and training. The modification of these variables implies programmatic decisions in areas such as orbital replacement unit (ORU) design, investment in repair capabilities, and crew operations policies. The model utilizes a wide range of algorithms and an extensive trial logistics data base to represent Space Station operations. The trial logistics data base consists largely of a collection of the ORUs that comprise the mature station, and their characteristics based on current engineering understanding of the Space Station. A nondimensional approach is used to examine the relative importance of variables on parameters.

  16. Analog Approach to Constraint Satisfaction Enabled by Spin Orbit Torque Magnetic Tunnel Junctions.

    PubMed

    Wijesinghe, Parami; Liyanagedera, Chamika; Roy, Kaushik

    2018-05-02

    Boolean satisfiability (k-SAT) is an NP-complete (k ≥ 3) problem that constitute one of the hardest classes of constraint satisfaction problems. In this work, we provide a proof of concept hardware based analog k-SAT solver, that is built using Magnetic Tunnel Junctions (MTJs). The inherent physics of MTJs, enhanced by device level modifications, is harnessed here to emulate the intricate dynamics of an analog satisfiability (SAT) solver. In the presence of thermal noise, the MTJ based system can successfully solve Boolean satisfiability problems. Most importantly, our results exhibit that, the proposed MTJ based hardware SAT solver is capable of finding a solution to a significant fraction (at least 85%) of hard 3-SAT problems, within a time that has a polynomial relationship with the number of variables(<50).

  17. Steric-electronic effects in malarial peptides inducing sterile immunity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Moreno-Vranich, Armando; Patarroyo, Manuel E., E-mail: mepatarr@mail.com; Universidad Nacional de Colombia, Bogota

    Highlights: Black-Right-Pointing-Pointer Is it evident that the residues position are relevant regarding of {phi} angular value. Black-Right-Pointing-Pointer The geometry considered for detailing the alterations undergone by HABPs. Black-Right-Pointing-Pointer The inter planar interactions ruled by clashes between the atoms making them up. -- Abstract: Conserved Plasmodium falciparum high activity binding peptides' (HABPs) most relevant proteins involved in malaria parasite invasion are immunologically silent; critical binding residues must therefore be specifically replaced to render them highly immunogenic and protection-inducing. Such changes have a tremendous impact on these peptides' steric-electronic effects, such as modifications to peptide length peptide bonds and electronic orbitals' disposition,more » to allow a better fit into immune system MHCII molecules and better interaction with the TCR which might account for the final immunological outcome.« less

  18. Synthesis and application of pyridine-based ambipolar hosts: control of charge balance in organic light emitting devices (OLEDs) by chemical structure modification

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Koech, Phillip K.; Polikarpov, Evgueni; Rainbolt, James E.

    2010-11-05

    Pyridine-based host materials were synthesized via Grignard metathesis of bromopyridines to provide the required organometallic reagent. The isomeric hosts (4-(9H-carbazol-9-yl)phenyl)(phenyl)(pyridin-3-yl)phosphine oxide (HM-A4), (5-(9H-carbazol-9-yl)pyridin-2-yl)diphenylphosphine oxide (HM-A5), and (5-(diphenylamino)pyridin-2-yl)diphenylphosphine oxide (HM-A6), (4-(diphenylamino)phenyl)(phenyl)(pyridin-3-yl)phosphine oxide (HM-A8) have similar frontier orbital energies. Organic light emitting devices (OLEDs) fabricated using the series of the host materials demonstrate that small structural modification of the host results in significant change in charge transporting ability.

  19. Disposal strategy for the geosynchronous orbits of the Beidou Navigation Satellite System

    NASA Astrophysics Data System (ADS)

    Tang, Jingshi; Liu, Lin

    Beidou Navigation Satellite System (BDS) is China's navigation satelite system. It is now operational for navigation service in China and Asia-Pacific region and is due to be fully operational as a global navigation system by 2020. Unlike other navigation satellite systems, BDS consists of both 12-hour medium Earth orbit and 24-hour geosynchronous orbit. To sustain a safe environment for the navigation satellites, the end-of-life satellites must be disposed appropriately so they do not pose potential dangers to the operational satellites. There are currently two strategies for the disposal orbit. One is to put the disposed satellite in a graveyard orbit that has a safe distance from the operational satellites. It is often applied in geosynchronous orbits and such graveyard orbit can always maintain a safe distance even for a few centuries. This strategy is also currently adopted by GPS, yet recent researches show a re-entry orbit can sometimes be a better alternative. The interaction of Earth oblateness and lunisolar gravitation can lead to a rapid increase in the orbit eccentricity such that by proper design the disposed GPS satellite can be cleared out by re-entry into the atmosphere. In this work we focus on the disposal strategy for BDS geosynchronous orbit, which consists of the equatorial stationary orbit (GEO) and the inclined orbit (IGSO). We show that these two orbits are essentially in two different dynamical environments and evolve quite distinctly over a long period of time. Taking advantage of the dynamic nature, we apply the graveyard orbit and the re-entry orbit to GEO and IGSO respectively and propose appropriate disposal strategies accordingly.

  20. KSC-07pd1827

    NASA Image and Video Library

    2007-07-11

    KENNEDY SPACE CENTER, FLA. -- The dawn sky over the Atlantic Ocean reveals Space Shuttle Endeavour sitting on Launch Pad 39A. First motion out of the Vehicle Assembly Building was at 8:10 p.m. July 10, and the shuttle was hard down on the pad at 3:02 a.m. July 11. The orbiter access arm is already extended to the orbiter from the fixed service structure. Peering just above the solid rocket booster on the left is the 290-foot-tall water tank. It provides the deluge over the mobile launcher platform for sound suppression during liftoff. Endeavour is scheduled to launch on mission STS-118 on Aug. 7. During the mission, Endeavour will carry into orbit the S5 truss, SPACEHAB module and external stowage platform 3. The mission is the 22nd flight to the International Space Station and will mark the first flight of Mission Specialist Barbara Morgan, the teacher-turned-astronaut whose association with NASA began more than 20 years ago. STS-118 will be the first flight since 2002 for Endeavour, which has undergone extensive modifications, including the addition of safety upgrades already added to orbiters Discovery and Atlantis. Photo credit: NASA/George Shelton

  1. KSC-07pd1826

    NASA Image and Video Library

    2007-07-11

    KENNEDY SPACE CENTER, FLA. -- The rising sun, at right, reveals Space Shuttle Endeavour sitting on Launch Pad 39A. First motion out of the Vehicle Assembly Building was at 8:10 p.m. July 10, and the shuttle was hard down on the pad at 3:02 a.m. July 11. On the left is the fixed service structure with the orbiter access arm already extended to the orbiter. The top of the 290-foot-tall water tank is seen to the right of the shuttle. It provides the deluge over the mobile launcher platform for sound suppression during liftoff. Endeavour is scheduled to launch on mission STS-118 on Aug. 7. During the mission, Endeavour will carry into orbit the S5 truss, SPACEHAB module and external stowage platform 3. The mission is the 22nd flight to the International Space Station and will mark the first flight of Mission Specialist Barbara Morgan, the teacher-turned-astronaut whose association with NASA began more than 20 years ago. STS-118 will be the first flight since 2002 for Endeavour, which has undergone extensive modifications, including the addition of safety upgrades already added to orbiters Discovery and Atlantis. Photo credit: NASA/George Shelton

  2. Composition and Cosmogonic Parameters of the Chemically Distinct Comet C/2007 N3 (Lulin)

    NASA Astrophysics Data System (ADS)

    Gibb, Erika L.; Villanueva, G. L.; Bonev, B. P.; DiSanti, M. A.; Mumma, M. J.; Radeva, Y. L.

    2012-10-01

    Comets are remnants from the early solar system that retain the volatiles (ices) from the cold outer proto-planetary disk (beyond 5 AU) where they formed. Comet nuclei were among the first objects to accrete in the early solar nebula and many of them were subsequently incorporated into the growing giant planets. Gravitational scattering redistributed the remaining comet population by either sending them to the inner solar system, where they may have enriched the early biosphere, or scattering them into their present-day dynamical reservoirs. Since this early time, comets have been orbiting the Sun relatively untouched by processing mechanisms, until their orbits are perturbed towards the inner solar system. As such, they are believed to be among the most primitive objects in the solar system and may be representative of the material from which the solar system formed. Of particular interest is their icy volatile composition since other solar system objects have either lost or have had significant modifications to their volatile compositions since their formation. Many of the volatiles observed in comets are also important prebiotic species. For example, H2CO is a chemical precursor to sugars and HCN and NH3 are precursors of amino acids. Studying comets is therefore a vital link to understanding the origin and evolution of our planetary system and life on Earth. We obtained high-resolution, near-infrared spectroscopic observations of Comet C/2007 N3 (Lulin) on 30 January - 1 February 2009 with NIRSPEC on Keck II. Lulin is an Oort Cloud comet with a very large aphelion distance, suggesting that it may have been dynamically new. We report production rates of H2O, C2H6, HCN, C2H2, CH4, NH3, H2CO, CH3OH, and CO. We also report two cosmogonic parameters: D/H ratio in H2O and CH4, and isomeric spin temperatures. The implications for comet formations scenarios are discussed.

  3. Infrared Spectroscopy of Symbiotic Stars. II. Orbits for Five S-Type Systems with Two-Year Periods

    NASA Astrophysics Data System (ADS)

    Fekel, Francis C.; Hinkle, Kenneth H.; Joyce, Richard R.; Skrutskie, Michael F.

    2000-12-01

    Infrared radial velocities have been used to determine orbital elements for the cool giants of five well-known symbiotic systems, Z And, AG Dra, V443 Her, AX Per, and FG Ser, all of which have orbital periods near the two-year mean period for S-type symbiotics. The new orbits are in general agreement with previous orbits derived from optical velocities. From the combined optical and infrared velocities, improved orbital elements for the five systems have been determined. Each of the orbital periods has been determined solely from the radial-velocity data. The orbits are circular and have quite small mass functions of 0.001-0.03 Msolar. The infrared velocities of AG Dra do not show the large orbital velocity residuals found for its optical radial velocities.

  4. Evaluation of TDRSS-user orbit determination accuracy using batch least-squares and sequential methods

    NASA Technical Reports Server (NTRS)

    Oza, D. H.; Jones, T. L.; Hodjatzadeh, M.; Samii, M. V.; Doll, C. E.; Hart, R. C.; Mistretta, G. D.

    1991-01-01

    The development of the Real-Time Orbit Determination/Enhanced (RTOD/E) system as a prototype system for sequential orbit determination on a Disk Operating System (DOS) based Personal Computer (PC) is addressed. The results of a study to compare the orbit determination accuracy of a Tracking and Data Relay Satellite System (TDRSS) user spacecraft obtained using RTOD/E with the accuracy of an established batch least squares system, the Goddard Trajectory Determination System (GTDS), is addressed. Independent assessments were made to examine the consistencies of results obtained by the batch and sequential methods. Comparisons were made between the forward filtered RTOD/E orbit solutions and definitive GTDS orbit solutions for the Earth Radiation Budget Satellite (ERBS); the maximum solution differences were less than 25 m after the filter had reached steady state.

  5. KSC-2009-5595

    NASA Image and Video Library

    2009-10-20

    CAPE CANAVERAL, Fla. – Workers prepare to close the arms of the vehicle stabilization system around the towering 327-foot-tall Ares I-X rocket, newly arrived on Launch Pad 39B at NASA's Kennedy Space Center in Florida. The test rocket left the Vehicle Assembly Building at 1:39 a.m. EDT on its 4.2-mile trek to the pad and was "hard down" on the pad’s pedestals at 9:17 a.m. The transfer of the pad from the Space Shuttle Program to the Constellation Program took place May 31. Modifications made to the pad include the removal of shuttle unique subsystems, such as the orbiter access arm and a section of the gaseous oxygen vent arm, along with the installation of three 600-foot lightning towers, access platforms, environmental control systems and a vehicle stabilization system. Part of the Constellation Program, the Ares I-X is the test vehicle for the Ares I. The Ares I-X flight test is targeted for Oct. 27. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo credit: NASA/Kim Shiflett

  6. KSC-2009-5596

    NASA Image and Video Library

    2009-10-20

    CAPE CANAVERAL, Fla. – The arms of the vehicle stabilization system are closed around the towering 327-foot-tall Ares I-X rocket, newly arrived on Launch Pad 39B at NASA's Kennedy Space Center in Florida. The test rocket left the Vehicle Assembly Building at 1:39 a.m. EDT on its 4.2-mile trek to the pad and was "hard down" on the pad’s pedestals at 9:17 a.m. The transfer of the pad from the Space Shuttle Program to the Constellation Program took place May 31. Modifications made to the pad include the removal of shuttle unique subsystems, such as the orbiter access arm and a section of the gaseous oxygen vent arm, along with the installation of three 600-foot lightning towers, access platforms, environmental control systems and a vehicle stabilization system. Part of the Constellation Program, the Ares I-X is the test vehicle for the Ares I. The Ares I-X flight test is targeted for Oct. 27. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo credit: NASA/Kim Shiflett

  7. Apollo Soyuz, mission evaluation report

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The Apollo Soyuz mission was the first manned space flight to be conducted jointly by two nations - the United States and the Union of Soviet Socialist Republics. The primary purpose of the mission was to test systems for rendezvous and docking of manned spacecraft that would be suitable for use as a standard international system, and to demonstrate crew transfer between spacecraft. The secondary purpose was to conduct a program of scientific and applications experimentation. With minor modifications, the Apollo and Soyuz spacecraft were like those flown on previous missions. However, a new module was built specifically for this mission - the docking module. It served as an airlock for crew transfer and as a structural base for the docking mechanism that interfaced with a similar mechanism on the Soyuz orbital module. The postflight evaluation of the performance of the docking system and docking module, as well as the overall performance of the Apollo spacecraft and experiments is presented. In addition, the mission is evaluated from the viewpoints of the flight crew, ground support operations, and biomedical operations. Descriptions of the docking mechanism, docking module, crew equipment and experiment hardware are given.

  8. KSC-2009-5916

    NASA Image and Video Library

    2009-10-27

    CAPE CANAVERAL, Fla. – As the sun rises over Launch Pad 39B at NASA's Kennedy Space Center in Florida, the rotating service structure and the arms of the vehicle stabilization system have been retracted from around the Constellation Program's 327-foot-tall Ares I-X rocket, resting atop its mobile launcher platform, for launch. The transfer of the pad from the Space Shuttle Program to the Constellation Program took place May 31. Modifications made to the pad include the removal of shuttle unique subsystems, such as the orbiter access arm and a section of the gaseous oxygen vent arm, and the installation of three 600-foot lightning towers, access platforms, environmental control systems and a vehicle stabilization system. The data returned from more than 700 sensors throughout the rocket will be used to refine the design of future launch vehicles and bring NASA one step closer to reaching its exploration goals. The Ares I-X flight test is targeted for Oct. 27. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo credit: NASA/Kim Shiflett

  9. KSC-2009-5911

    NASA Image and Video Library

    2009-10-27

    CAPE CANAVERAL, Fla. – Workers on Launch Pad 39B at NASA's Kennedy Space Center in Florida prepare the Constellation Program's 327-foot-tall Ares I-X rocket for launch. The rotating service structure and the arms of the vehicle stabilization system will be moved from around the rocket for liftoff. The transfer of the pad from the Space Shuttle Program to the Constellation Program took place May 31. Modifications made to the pad include the removal of shuttle unique subsystems, such as the orbiter access arm and a section of the gaseous oxygen vent arm, and the installation of three 600-foot lightning towers, access platforms, environmental control systems and a vehicle stabilization system. The data returned from more than 700 sensors throughout the rocket will be used to refine the design of future launch vehicles and bring NASA one step closer to reaching its exploration goals. The Ares I-X flight test is targeted for Oct. 27. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo credit: NASA/Kim Shiflett

  10. KSC-2009-5912

    NASA Image and Video Library

    2009-10-27

    CAPE CANAVERAL, Fla. - Workers on Launch Pad 39B at NASA's Kennedy Space Center in Florida make final preparations for launch of the Constellation Program's 327-foot-tall Ares I-X rocket. The rotating service structure and the arms of the vehicle stabilization system will be moved from around the rocket for liftoff. The transfer of the pad from the Space Shuttle Program to the Constellation Program took place May 31. Modifications made to the pad include the removal of shuttle unique subsystems, such as the orbiter access arm and a section of the gaseous oxygen vent arm, and the installation of three 600-foot lightning towers, access platforms, environmental control systems and a vehicle stabilization system. The data returned from more than 700 sensors throughout the rocket will be used to refine the design of future launch vehicles and bring NASA one step closer to reaching its exploration goals. The Ares I-X flight test is targeted for Oct. 27. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo credit: NASA/Kim Shiflett

  11. Atmospheric effects on radiation reflected from soil and vegetation as measured by orbital sensors using various scanning directions

    NASA Technical Reports Server (NTRS)

    Slater, P. N.; Jackson, R. D.

    1982-01-01

    Ground-measured spectral reflectance data for Avondale loam and drought-stressed and unstressed wheat were converted into digital counts for spectral bands 5 and 7 of the Landsat Multispectral Scanner System (MSS). For dry loam, the differences between ratios of MSS bands 7-5 as determined from space and from ground level measurements were 2.3 percent for clear and 5.6 percent for turbid atmospheric conditions. By contrast, for wet loam the differences were 10.4 and 29.5 percent. It is found that atmospheric conditions may cause a delay of from 3 to 7 days in the discrimination between drought-stressed and unstressed wheat. For oblique angle observations the atmospheric modification of ground-measured reflectances increased with angle at a greater rate in the 0/180 deg azimuth than in the 90/270 deg azimuth. Implications of this result are discussed for oblique angle Systeme Probatoire d'Observation de la Terre (SPOT), Mapsat, future multispectral linear array system imagery, and wide-angle imagery collected from scanners in high-altitude aircraft.

  12. Performance capabilities of the 12-centimeter Xenon ion thruster

    NASA Technical Reports Server (NTRS)

    Mantenieks, M.; Schatz, M.

    1984-01-01

    The 8- and 12-cm mercury ion thruster systems were developed primarily to provide N-S station keeping of satellites with masses up to about 1800 to 3600 kg respectively. The on-orbit propulsion requirements of recently proposed Large Space Systems (LSS) are beyond the thrust capabilities of the baseline 8- and 12-cm thruster systems. This paper presents a characterization of the performance capabilities of the 12-cm Xenon ion thruster to enable an evaluation of its application to LSS auxiliary propulsion requirements. With minor thruster modifications and simplifications the thrust was increased to 64 mN, a factor of six over the baseline 12-cm mercury thruster performance. The thruster was operated over a range of specific impulse of about 2000 to 4000 seconds and at total efficiencies up to 68.0 percent. The operating levels reached in this study were found to be close to the operating limits of the thruster design in terms of perveance, grid breakdown voltage and thruster component temperatures such as those of the magnets and cathode baffle.

  13. Writing with ring currents: selectively hydrogenated polycyclic aromatics as finite models of graphene and graphane

    PubMed Central

    Fowler, Patrick W.; Gibson, Christopher M.; Bean, David E.

    2014-01-01

    Alternating partial hydrogenation of the interior region of a polycyclic aromatic hydrocarbon gives a finite model system representing systems on the pathway from graphene to the graphane modification of the graphene sheet. Calculations at the DFT and coupled Hartree–Fock levels confirm that sp2 cycles of bare carbon centres isolated by selective hydrogenation retain the essentially planar geometry and electron delocalization of the annulene that they mimic. Delocalization is diagnosed by the presence of ring currents, as detected by ipsocentric calculation and visualization of the current density induced in the π system by a perpendicular external magnetic field. These induced ‘ring’ currents have essentially the same sense, strength and orbital origin as in the free hydrocarbon. Subjected to the important experimental proviso of the need for atomic-scale control of hydrogenation, this finding predicts the possibility of writing single, multiple and concentric diatropic and/or paratropic ring currents on the graphene/graphane sheet. The implication is that pathways for free flow of ballistic current can be modelled in the same way. PMID:24611026

  14. Preliminary orbital parallax catalog

    NASA Technical Reports Server (NTRS)

    Halliwell, M.

    1981-01-01

    The study is undertaken to calibrate the more reliable parallaxes derived from a comparison of visual and spectroscopic orbits and to encourage observational studies of other promising binaries. The methodological techniques used in computing orbital parallaxes are analyzed. Tables summarizing orbital data and derived system properties are then given. Also given is a series of detailed discussions of the 71 individual systems included in the tables. Data are listed for 57 other systems which are considered promising candidates for eventual orbital parallax determination.

  15. Fast global orbit feedback system in PLS-II

    NASA Astrophysics Data System (ADS)

    Lee, J.; Kim, C.; Kim, J. M.; Kim, K. R.; Lee, E. H.; Lee, J. W.; Lee, T. Y.; Park, C. D.; Shin, S.; Yoon, J. C.; Cho, W. S.; Park, G. S.; Kim, S. C.

    2016-12-01

    The transverse position of the electron beam in the Pohang Light Source-II is stabilized by the global orbit feedback system. A slow orbit feedback system has been operating at 2 Hz, and a fast orbit feedback (FOFB) system at 813 Hz was installed recently. This FOFB system consists of 96 electron-beam-position monitors, 48 horizontal fast correctors, 48 vertical fast correctors and Versa Module Europa bus control system. We present the design and implementation of the FOFB system and its test result. Simulation analysis is presented and future improvements are suggested.

  16. STS-68 on Runway with 747 SCA/Columbia Ferry Flyby

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The space shuttle Endeavour receives a high-flying salute from its sister shuttle, Columbia, atop NASA's Shuttle Carrier Aircraft, shortly after Endeavor's landing 12 October 1994, at Edwards, California, to complete mission STS-68. Columbia was being ferried from the Kennedy Space Center, Florida, to Air Force Plant 42, Palmdale, California, where it will undergo six months of inspections, modifications, and systems upgrades. The STS-68 11-day mission was devoted to radar imaging of Earth's geological features with the Space Radar Laboratory. The orbiter is surrounded by equipment and personnel that make up the ground support convoy that services the space vehicles as soon as they land. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain inside the payload bay throughout the mission. They are then removed after the Space Shuttle returns to Earth and can be reused on future flights. Some of these orbital laboratories, like the Spacelab, provide facilities for several specialists to conduct experiments in such fields as medicine, astronomy, and materials manufacturing. Some types of satellites deployed by Space Shuttles include those involved in environmental and resources protection, astronomy, weather forecasting, navigation, oceanographic studies, and other scientific fields. The Space Shuttles can also launch spacecraft into orbits higher than the Shuttle's altitude limit through the use of Inertial Upper Stage (IUS) propulsion units. After release from the Space Shuttle payload bay, the IUS is ignited to carry the spacecraft into deep space. The Space Shuttles are also being used to carry elements of the International Space Station into space where they are assembled in orbit. The Space Shuttles were built by Rockwell International's Space Transportation Systems Division, Downey, California. Rockwell's Rocketdyne Division (now part of Boeing) builds the three main engines, and Thiokol, Brigham City, Utah, makes the solid rocket booster motors. Martin Marietta Corporation (now Lockheed Martin), New Orleans, Louisiana, makes the external tanks. Each orbiter (Space Shuttle) is 121 feet long, has a wingspan of 78 feet, and a height of 57 feet. The Space Shuttle is approximately the size of a DC-9 commercial airliner and can carry a payload of 65,000 pounds into orbit. The payload bay is 60 feet long and 15 feet in diameter. Each main engine is capable of producing a sea level thrust of 375,000 pounds and a vacuum (orbital) thrust of 470,000 pounds. The engines burn a mixture of liquid oxygen and liquid hydrogen. In orbit, the Space Shuttles circle the earth at a speed of 17,500 miles per hour with each orbit taking about 90 minutes. A Space Shuttle crew sees a sunrise or sunset every 45 minutes. When Space Shuttle flights began in April 1981, Dryden Flight Research Center, Edwards, California, was the primary landing site for the Shuttles. Now Kennedy Space Center, Florida, is the primary landing site with Dryden remaining as the principal alternate landing site.

  17. STS-68 on Runway with 747 SCA - Columbia Ferry Flyby

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The space shuttle Endeavour receives a high-flying salute from its sister shuttle, Columbia, atop NASA's Shuttle Carrier Aircraft, shortly after Endeavor's landing 12 October 1994, at Edwards, California, to complete mission STS-68. Columbia was being ferried from the Kennedy Space Center, Florida, to Air Force Plant 42, Palmdale, California, where it will undergo six months of inspections, modifications, and systems upgrades. The STS-68 11-day mission was devoted to radar imaging of Earth's geological features with the Space Radar Laboratory. The orbiter is surrounded by equipment and personnel that make up the ground support convoy that services the space vehicles as soon as they land. Space Shuttles are the main element of America's Space Transportation System and are used for space research and other space applications. The shuttles are the first vehicles capable of being launched into space and returning to Earth on a routine basis. Space Shuttles are used as orbiting laboratories in which scientists and mission specialists conduct a wide variety of scientific experiments. Crews aboard shuttles place satellites in orbit, rendezvous with satellites to carry out repair missions and return them to space, and retrieve satellites and return them to Earth for refurbishment and reuse. Space Shuttles are true aerospace vehicles. They leave Earth and its atmosphere under rocket power provided by three liquid-propellant main engines with two solid-propellant boosters attached plus an external liquid-fuel tank. After their orbital missions, they streak back through the atmosphere and land like airplanes. The returning shuttles, however, land like gliders, without power and on runways. Other rockets can place heavy payloads into orbit, but, they can only be used once. Space Shuttles are designed to be continually reused. When Space Shuttles are used to transport complete scientific laboratories into space, the laboratories remain inside the payload bay throughout the mission. They are then removed after the Space Shuttle returns to Earth and can be reused on future flights. Some of these orbital laboratories, like the Spacelab, provide facilities for several specialists to conduct experiments in such fields as medicine, astronomy, and materials manufacturing. Some types of satellites deployed by Space Shuttles include those involved in environmental and resources protection, astronomy, weather forecasting, navigation, oceanographic studies, and other scientific fields. The Space Shuttles can also launch spacecraft into orbits higher than the Shuttle's altitude limit through the use of Inertial Upper Stage (IUS) propulsion units. After release from the Space Shuttle payload bay, the IUS is ignited to carry the spacecraft into deep space. The Space Shuttles are also being used to carry elements of the International Space Station into space where they are assembled in orbit. The Space Shuttles were built by Rockwell International's Space Transportation Systems Division, Downey, California. Rockwell's Rocketdyne Division (now part of Boeing) builds the three main engines, and Thiokol, Brigham City, Utah, makes the solid rocket booster motors. Martin Marietta Corporation (now Lockheed Martin), New Orleans, Louisiana, makes the external tanks. Each orbiter (Space Shuttle) is 121 feet long, has a wingspan of 78 feet, and a height of 57 feet. The Space Shuttle is approximately the size of a DC-9 commercial airliner and can carry a payload of 65,000 pounds into orbit. The payload bay is 60 feet long and 15 feet in diameter. Each main engine is capable of producing a sea level thrust of 375,000 pounds and a vacuum (orbital) thrust of 470,000 pounds. The engines burn a mixture of liquid oxygen and liquid hydrogen. In orbit, the Space Shuttles circle the earth at a speed of 17,500 miles per hour with each orbit taking about 90 minutes. A Space Shuttle crew sees a sunrise or sunset every 45 minutes. When Space Shuttle flights began in April 1981, Dryden Flight Research Center, Edwards, California, was the primary landing site for the Shuttles. Now Kennedy Space Center, Florida, is the primary landing site with Dryden remaining as the principal alternate landing site.

  18. Propulsion System and Orbit Maneuver Integration in CubeSats: Trajectory Control Strategies Using Micro Ion Propulsion

    NASA Technical Reports Server (NTRS)

    Hudson, Jennifer; Martinez, Andres; Petro, Andrew

    2015-01-01

    The Propulsion System and Orbit Maneuver Integration in CubeSats project aims to solve the challenges of integrating a micro electric propulsion system on a CubeSat in order to perform orbital maneuvers and control attitude. This represents a fundamentally new capability for CubeSats, which typically do not contain propulsion systems and cannot maneuver far beyond their initial orbits.

  19. Closeup view of the payload bay side of the aft ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Close-up view of the payload bay side of the aft fuselage bulkhead of the Orbiter Discovery. This image has a detailed portions of the Remote Manipulator System and the Orbiter Maneuvering System/Reaction Control System Pods. This photograph wa taken in the Orbiter Processing Facility at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  20. Ultrafast optical modification of exchange interactions in iron oxides

    PubMed Central

    Mikhaylovskiy, R.V.; Hendry, E.; Secchi, A.; Mentink, J.H.; Eckstein, M.; Wu, A.; Pisarev, R.V.; Kruglyak, V.V.; Katsnelson, M.I.; Rasing, Th.; Kimel, A.V.

    2015-01-01

    Ultrafast non-thermal manipulation of magnetization by light relies on either indirect coupling of the electric field component of the light with spins via spin-orbit interaction or direct coupling between the magnetic field component and spins. Here we propose a scenario for coupling between the electric field of light and spins via optical modification of the exchange interaction, one of the strongest quantum effects with strength of 103 Tesla. We demonstrate that this isotropic opto-magnetic effect, which can be called inverse magneto-refraction, is allowed in a material of any symmetry. Its existence is corroborated by the experimental observation of terahertz emission by spin resonances optically excited in a broad class of iron oxides with a canted spin configuration. From its strength we estimate that a sub-picosecond modification of the exchange interaction by laser pulses with fluence of about 1 mJ cm−2 acts as a pulsed effective magnetic field of 0.01 Tesla. PMID:26373688

  1. Ultrafast optical modification of exchange interactions in iron oxides.

    PubMed

    Mikhaylovskiy, R V; Hendry, E; Secchi, A; Mentink, J H; Eckstein, M; Wu, A; Pisarev, R V; Kruglyak, V V; Katsnelson, M I; Rasing, Th; Kimel, A V

    2015-09-16

    Ultrafast non-thermal manipulation of magnetization by light relies on either indirect coupling of the electric field component of the light with spins via spin-orbit interaction or direct coupling between the magnetic field component and spins. Here we propose a scenario for coupling between the electric field of light and spins via optical modification of the exchange interaction, one of the strongest quantum effects with strength of 10(3) Tesla. We demonstrate that this isotropic opto-magnetic effect, which can be called inverse magneto-refraction, is allowed in a material of any symmetry. Its existence is corroborated by the experimental observation of terahertz emission by spin resonances optically excited in a broad class of iron oxides with a canted spin configuration. From its strength we estimate that a sub-picosecond modification of the exchange interaction by laser pulses with fluence of about 1 mJ cm(-2) acts as a pulsed effective magnetic field of 0.01 Tesla.

  2. Computer graphics applications to crew displays

    NASA Technical Reports Server (NTRS)

    Wyzkoski, J.

    1983-01-01

    Astronauts are provided much data and information via the monochrome CRT displays on the orbiter. For this project two areas were investigated for the possible introduction of computer graphics to enhance and extend the utility of these displays. One involved reviewing the current orbiter displays and identifying those which could be improved via computer graphics. As an example, the tabular data on electrical power distribution and control was enhanced by the addition of color and bar charts. The other dealt with the development of an aid to berthing a payload with the Remote Manipulator System (RMS). This aid consists of a graphics display of the top, front and side views of the payload and cargo bay and point of resolution (POR) position and attitude data for the current location of the payload. The initial implementation was on an IBM PC clone. The demonstration software installed in the Johnson Space Center Manipulator Development Facility (MD) was reviewed. Due to current hardware limitations, the MDF verision is slow, i.e., about a 40+ seond update rate and, hence, not real-time. Despite this fact, the evaluation of this additional visual cue as an RMS operator aid indicates that this display, with modifications for speed, etc., can assist the crew. Further development is appropriate.

  3. Signs of Landscape Modifications at Martian Crater

    NASA Technical Reports Server (NTRS)

    2009-01-01

    [figure removed for brevity, see original site] Click on the image for larger version

    The lower portion of this image from the Thermal Emission Imaging System camera (THEMIS) on NASA's Mars Odyssey orbiter shows a crater about 16 kilometers (10 miles) in diameter with features studied as evidence of deposition or erosion. The crater is centered at 40.32 degrees south latitude and 132.5 degrees east longitude, in the eastern portion of the Hellas basin on Mars. It has gullies and arcuate ridges on its north, pole-facing interior wall. This crater is in the center of a larger (60-kilometer or 37-mile diameter) crater with lobate flows on its north, interior wall. The image, number V07798008 in the THEMIS catalog, covers a swath of ground 17.4 kilometers (10.8 miles) wide.

    NASA's Jet Propulsion Laboratory manages the Mars Odyssey mission for NASA's Office of Space Science. THEMIS was developed by Arizona State University in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  4. Guidance Scheme for Modulation of Drag Devices to Enable Return from Low Earth Orbit

    NASA Technical Reports Server (NTRS)

    Dutta, Soumyo; Bowes, Angela L.; Cianciolo, Alicia D.; Glass, Christopher E.; Powell, Richard W.

    2017-01-01

    Passive drag devices provide opportunities to return payloads from low Earth orbits quickly without using onboard propulsive systems to de-orbit the spacecraft. However, one potential disadvantage of such systems has been the lack of landing accuracy. Drag modulation or changing the shape of the drag device during flight offer a way to control the de-orbit trajectory and target a specific landing location. This paper discusses a candidate passive drag based system, called Exo-brake, as well as efforts to model the dynamics of the vehicle as it de-orbits and guidance schemes used to control the trajectory. Such systems can enable quick return of payloads from low Earth orbit assets like the International Space Station without the use of large re-entry cargo capsules or propulsive systems.

  5. The port side view of the Orbiter Discovery while mounted ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    The port side view of the Orbiter Discovery while mounted atop the 76-wheeled orbiter transfer system as it is being rolled from the Orbiter Processing Facility to the Vehicle Assembly Building at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  6. The starboard side view of the Orbiter Discovery while mounted ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    The starboard side view of the Orbiter Discovery while mounted atop the 76-wheeled orbiter transfer system as it is being rolled from the Orbiter Processing Facility to the Vehicle Assembly Building at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  7. Computing Rydberg Electron Transport Rates Using Periodic Orbits

    NASA Astrophysics Data System (ADS)

    Sattari, Sulimon; Mitchel, Kevin

    2017-04-01

    Electron transport rates in chaotic atomic systems are computable from classical periodic orbits. This technique allows for replacing a Monte Carlo simulation launching millions of orbits with a sum over tens or hundreds of properly chosen periodic orbits using a formula called the spectral determiant. A firm grasp of the structure of the periodic orbits is required to obtain accurate transport rates. We apply a technique called homotopic lobe dynamics (HLD) to understand the structure of periodic orbits to compute the ionization rate in a classically chaotic atomic system, namely the hydrogen atom in strong parallel electric and magnetic fields. HLD uses information encoded in the intersections of stable and unstable manifolds of a few orbits to compute relevant periodic orbits in the system. All unstable periodic orbits are computed up to a given period, and the ionization rate computed from periodic orbits converges exponentially to the true value as a function of the period used. Using periodic orbit continuation, the ionization rate is computed over a range of electron energy and magnetic field values. The future goal of this work is to semiclassically compute quantum resonances using periodic orbits.

  8. A weight modification sequential method for VSC-MTDC power system state estimation

    NASA Astrophysics Data System (ADS)

    Yang, Xiaonan; Zhang, Hao; Li, Qiang; Guo, Ziming; Zhao, Kun; Li, Xinpeng; Han, Feng

    2017-06-01

    This paper presents an effective sequential approach based on weight modification for VSC-MTDC power system state estimation, called weight modification sequential method. The proposed approach simplifies the AC/DC system state estimation algorithm through modifying the weight of state quantity to keep the matrix dimension constant. The weight modification sequential method can also make the VSC-MTDC system state estimation calculation results more ccurate and increase the speed of calculation. The effectiveness of the proposed weight modification sequential method is demonstrated and validated in modified IEEE 14 bus system.

  9. Mission analysis data for inclined geosynchronous orbits, part 1

    NASA Technical Reports Server (NTRS)

    Graf, O. F., Jr.; Wang, K. C.

    1980-01-01

    Data needed for preliminary design of inclined geosynchronous missions are provided. The inertial and Earth fixed coordinate systems are described, as well as orbit parameters and elements. The complete family of geosynchronous orbits is discussed. It is shown that circular inclined geosynchronous orbits comprise only one set in this family. The major orbit perturbation and their separate effects on the geosynchronous orbit are discussed. Detailed information on the orbit perturbation of inclined circular geosynchronous orbits is given, with emphasis on time history data of certain orbital elements. Orbit maintenance delta velocity (V) requirements to counteract the major orbit perturbations are determined in order to provide order of magnitude estimates and to show the effects of orbit inclination on delta V. Some of the considerations in mission design for a multisatellite system, such as a halo orbit constellation, are discussed.

  10. Investigations into the Properties, Conditions, and Effects of the Ionosphere.

    DTIC Science & Technology

    1988-01-15

    Innovative Approaches to Direct Measurement of N e 28 ]- J FEASIBILITY OF RADIO BLACKOUT MITIGATION IN THE BRAKING PHASE 28 OF AOTV OPERATIONS 1. Brief...Cell could be tested under simulated flight conditions in the SAIC plasma laboratory facility. AJ. FEASIBILITY OF RADIO BLACKOUT MITIGATION IN THE...enable calculation of chemical modification techniques ,. on phenomena of radio blackout during re-entry of orbiting spacecraft . * ,1. Brief

  11. Satellite time and frequency transfer (STIFT)

    NASA Technical Reports Server (NTRS)

    Vessot, R. F. C.

    1983-01-01

    The concept of placing a hydrogen maser high stability clock in Earth orbit to provide accurate time and frequency comparisons worldwide to major timing centers and to a large number of radio observatory antenna sites involved in VLBI measurements was studied. The proposal was chiefly directed toward studies and initial hardware designs for time comparisons between hydrogen maser frequency standards and to modifications of the hydrogen maser for long-term use in space.

  12. Strategies for Stabilizing Nitrogenous Compounds in ECLSS Wastewater: Top-Down System Design and Unit Operation Selection with Focus on Bio-Regenerative Processes for Short and Long Term Scenarios

    NASA Technical Reports Server (NTRS)

    Lunn, Griffin M.

    2011-01-01

    Water recycling and eventual nutrient recovery is crucial for surviving in or past low earth orbit. New approaches and syste.m architecture considerations need to be addressed to meet current and future system requirements. This paper proposes a flexible system architecture that breaks down pretreatment , steps into discrete areas where multiple unit operations can be considered. An overview focusing on the urea and ammonia conversion steps allows an analysis on each process's strengths and weaknesses and synergy with upstream and downstream processing. Process technologies to be covered include chemical pretreatment, biological urea hydrolysis, chemical urea hydrolysis, combined nitrification-denitrification, nitrate nitrification, anammox denitrification, and regenerative ammonia absorption through struvite formation. Biological processes are considered mainly for their ability to both maximize water recovery and to produce nutrients for future plant systems. Unit operations can be considered for traditional equivalent system mass requirements in the near term or what they can provide downstream in the form of usable chemicals or nutrients for the long term closed-loop ecological control and life support system. Optimally this would allow a system to meet the former but to support the latter without major modification.

  13. Tube dynamics and low energy Earth-Moon transfers in the 4-body system

    NASA Astrophysics Data System (ADS)

    Onozaki, Kaori; Yoshimura, Hiroaki; Ross, Shane D.

    2017-11-01

    In this paper, we show a low energy Earth-Moon transfer in the context of the Sun-Earth-Moon-spacecraft 4-body system. We consider the 4-body system as the coupled system of the Sun-Earth-spacecraft 3-body system perturbed by the Moon (which we call the Moon-perturbed system) and the Earth-Moon-spacecraft 3-body system perturbed by the Sun (which we call the Sun-perturbed system). In both perturbed systems, analogs of the stable and unstable manifolds are computed numerically by using the notion of Lagrangian coherent structures, wherein the stable and unstable manifolds play the role of separating orbits into transit and non-transit orbits. We obtain a family of non-transit orbits departing from a low Earth orbit in the Moon-perturbed system, and a family of transit orbits arriving into a low lunar orbit in the Sun-perturbed system. Finally, we show that we can construct a low energy transfer from the Earth to the Moon by choosing appropriate trajectories from both families and patching these trajectories with a maneuver.

  14. Optimal transfers between libration-point orbits in the elliptic restricted three-body problem

    NASA Astrophysics Data System (ADS)

    Hiday, Lisa Ann

    1992-09-01

    A strategy is formulated to design optimal impulsive transfers between three-dimensional libration-point orbits in the vicinity of the interior L(1) libration point of the Sun-Earth/Moon barycenter system. Two methods of constructing nominal transfers, for which the fuel cost is to be minimized, are developed; both inferior and superior transfers between two halo orbits are considered. The necessary conditions for an optimal transfer trajectory are stated in terms of the primer vector. The adjoint equation relating reference and perturbed trajectories in this formulation of the elliptic restricted three-body problem is shown to be distinctly different from that obtained in the analysis of trajectories in the two-body problem. Criteria are established whereby the cost on a nominal transfer can be improved by the addition of an interior impulse or by the implementation of coastal arcs in the initial and final orbits. The necessary conditions for the local optimality of a time-fixed transfer trajectory possessing additional impulses are satisfied by requiring continuity of the Hamiltonian and the derivative of the primer vector at all interior impulses. The optimality of a time-free transfer containing coastal arcs is surmised by examination of the slopes at the endpoints of a plot of the magnitude of the primer vector over the duration of the transfer path. If the initial and final slopes of the primer magnitude are zero, the transfer trajectory is optimal; otherwise, the execution of coasts is warranted. The position and timing of each interior impulse applied to a time-fixed transfer as well as the direction and length of coastal periods implemented on a time-free transfer are specified by the unconstrained minimization of the appropriate variation in cost utilizing a multivariable search technique. Although optimal solutions in some instances are elusive, the time-fixed and time-free optimization algorithms prove to be very successful in diminishing costs on nominal transfer trajectories. The inclusion of coastal arcs on time-free superior and inferior transfers results in significant modification of the transfer time of flight caused by shifts in departure and arrival locations on the halo orbits.

  15. Closeup view of the aft fuselage of the Orbiter Discovery ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Close-up view of the aft fuselage of the Orbiter Discovery on the starboard side looking forward. This view is of the attach surface for the Orbiter Maneuvering System/Reaction Control System (OMS/RCS) Pod. The OMS/RCS pods are removed for processing and reconditioning at another facility. This view was taken from a service platform in the Orbiter Processing Facility at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  16. Port side view of the Orbiter Discovery from an elevated ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Port side view of the Orbiter Discovery from an elevated platform in the Vehicle Assembly Building at NASA's Kennedy Space Center. Note the ground support hardware known as Strongbacks attached to the payload bay doors, the crew access hatch below the name Discovery on the forward section of the Orbiter and the removed Orbiter Maneuvering System/Reaction Control System pod from the aft (tai) section. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  17. General view of the aft section of the Orbiter Discovery ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view of the aft section of the Orbiter Discovery in the Vehicle Assembly Building at NASA's Kennedy Space Center. Note the main engines and Orbiter Maneuvering System/Reaction Control System pods are removed in this photo. The flexible hoses protruding from the starboard aft section are to control temperature, humidity and pressure in the orbiter's void spaces during its down time. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  18. General view of the aft, starboard section of the Orbiter ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view of the aft, starboard section of the Orbiter Discovery in the Vehicle Assembly Building at NASA's Kennedy Space Center. Note the main engines and Orbiter Maneuvering System/Reaction Control System pods are removed in this photo. The flexible hoses protruding from the starboard aft section are to control temperature, humidity and pressure in the orbiter's void spaces during its down time. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  19. Orbit determination of the Next-Generation Beidou satellites with Intersatellite link measurements and a priori orbit constraints

    NASA Astrophysics Data System (ADS)

    Ren, Xia; Yang, Yuanxi; Zhu, Jun; Xu, Tianhe

    2017-11-01

    Intersatellite Link (ISL) technology helps to realize the auto update of broadcast ephemeris and clock error parameters for Global Navigation Satellite System (GNSS). ISL constitutes an important approach with which to both improve the observation geometry and extend the tracking coverage of China's Beidou Navigation Satellite System (BDS). However, ISL-only orbit determination might lead to the constellation drift, rotation, and even lead to the divergence in orbit determination. Fortunately, predicted orbits with good precision can be used as a priori information with which to constrain the estimated satellite orbit parameters. Therefore, the precision of satellite autonomous orbit determination can be improved by consideration of a priori orbit information, and vice versa. However, the errors of rotation and translation in a priori orbit will remain in the ultimate result. This paper proposes a constrained precise orbit determination (POD) method for a sub-constellation of the new Beidou satellite constellation with only a few ISLs. The observation model of dual one-way measurements eliminating satellite clock errors is presented, and the orbit determination precision is analyzed with different data processing backgrounds. The conclusions are as follows. (1) With ISLs, the estimated parameters are strongly correlated, especially the positions and velocities of satellites. (2) The performance of determined BDS orbits will be improved by the constraints with more precise priori orbits. The POD precision is better than 45 m with a priori orbit constrain of 100 m precision (e.g., predicted orbits by telemetry tracking and control system), and is better than 6 m with precise priori orbit constraints of 10 m precision (e.g., predicted orbits by international GNSS monitoring & Assessment System (iGMAS)). (3) The POD precision is improved by additional ISLs. Constrained by a priori iGMAS orbits, the POD precision with two, three, and four ISLs is better than 6, 3, and 2 m, respectively. (4) The in-plane link and out-of-plane link have different contributions to observation configuration and system observability. The POD with weak observation configuration (e.g., one in-plane link and one out-of-plane link) should be tightly constrained with a priori orbits.

  20. Performance Characteristics For The Orbiter Camera Payload System's Large Format Camera (LFC)

    NASA Astrophysics Data System (ADS)

    MoIIberg, Bernard H.

    1981-11-01

    The Orbiter Camera Payload System, the OCPS, is an integrated photographic system which is carried into Earth orbit as a payload in the Shuttle Orbiter vehicle's cargo bay. The major component of the OCPS is a Large Format Camera (LFC) which is a precision wide-angle cartographic instrument that is capable of produc-ing high resolution stereophotography of great geometric fidelity in multiple base to height ratios. The primary design objective for the LFC was to maximize all system performance characteristics while maintaining a high level of reliability compatible with rocket launch conditions and the on-orbit environment.

  1. The Spin-Orbit Resonances of the Solar System: A Mathematical Treatment Matching Physical Data

    NASA Astrophysics Data System (ADS)

    Antognini, Francesco; Biasco, Luca; Chierchia, Luigi

    2014-06-01

    In the mathematical framework of a restricted, slightly dissipative spin-orbit model, we prove the existence of periodic orbits for astronomical parameter values corresponding to all satellites of the Solar System observed in exact spin-orbit resonance.

  2. Impacts of Earth rotation parameters on GNSS ultra-rapid orbit prediction: Derivation and real-time correction

    NASA Astrophysics Data System (ADS)

    Wang, Qianxin; Hu, Chao; Xu, Tianhe; Chang, Guobin; Hernández Moraleda, Alberto

    2017-12-01

    Analysis centers (ACs) for global navigation satellite systems (GNSSs) cannot accurately obtain real-time Earth rotation parameters (ERPs). Thus, the prediction of ultra-rapid orbits in the international terrestrial reference system (ITRS) has to utilize the predicted ERPs issued by the International Earth Rotation and Reference Systems Service (IERS) or the International GNSS Service (IGS). In this study, the accuracy of ERPs predicted by IERS and IGS is analyzed. The error of the ERPs predicted for one day can reach 0.15 mas and 0.053 ms in polar motion and UT1-UTC direction, respectively. Then, the impact of ERP errors on ultra-rapid orbit prediction by GNSS is studied. The methods for orbit integration and frame transformation in orbit prediction with introduced ERP errors dominate the accuracy of the predicted orbit. Experimental results show that the transformation from the geocentric celestial references system (GCRS) to ITRS exerts the strongest effect on the accuracy of the predicted ultra-rapid orbit. To obtain the most accurate predicted ultra-rapid orbit, a corresponding real-time orbit correction method is developed. First, orbits without ERP-related errors are predicted on the basis of ITRS observed part of ultra-rapid orbit for use as reference. Then, the corresponding predicted orbit is transformed from GCRS to ITRS to adjust for the predicted ERPs. Finally, the corrected ERPs with error slopes are re-introduced to correct the predicted orbit in ITRS. To validate the proposed method, three experimental schemes are designed: function extrapolation, simulation experiments, and experiments with predicted ultra-rapid orbits and international GNSS Monitoring and Assessment System (iGMAS) products. Experimental results show that using the proposed correction method with IERS products considerably improved the accuracy of ultra-rapid orbit prediction (except the geosynchronous BeiDou orbits). The accuracy of orbit prediction is enhanced by at least 50% (error related to ERP) when a highly accurate observed orbit is used with the correction method. For iGMAS-predicted orbits, the accuracy improvement ranges from 8.5% for the inclined BeiDou orbits to 17.99% for the GPS orbits. This demonstrates that the correction method proposed by this study can optimize the ultra-rapid orbit prediction.

  3. Proving the Space Transportation System: the Orbital Flight Test Program

    NASA Technical Reports Server (NTRS)

    Reichhardt, T.

    1982-01-01

    The main propulsion system, solid rocket boosters, external tank, orbital maneuvering system, spacecraft orbital operations (thermal tests, attitude control and remote manipulator), and return to Earth are outlined for the first four STS missions.

  4. A minimum propellant solution to an orbit-to-orbit transfer using a low thrust propulsion system

    NASA Technical Reports Server (NTRS)

    Cobb, Shannon S.

    1991-01-01

    The Space Exploration Initiative is considering the use of low thrust (nuclear electric, solar electric) and intermediate thrust (nuclear thermal) propulsion systems for transfer to Mars and back. Due to the duration of such a mission, a low thrust minimum-fuel solution is of interest; a savings of fuel can be substantial if the propulsion system is allowed to be turned off and back on. This switching of the propulsion system helps distinguish the minimal-fuel problem from the well-known minimum-time problem. Optimal orbit transfers are also of interest to the development of a guidance system for orbital maneuvering vehicles which will be needed, for example, to deliver cargoes to the Space Station Freedom. The problem of optimizing trajectories for an orbit-to-orbit transfer with minimum-fuel expenditure using a low thrust propulsion system is addressed.

  5. A possible space VLBI constellation utilizing the stable orbits around the TLPs in the Earth-Moon system.

    NASA Astrophysics Data System (ADS)

    Liu, Bin; Tang, Jingshi; Hou, Xiyun

    2016-07-01

    Current studies indicate that there are stable orbits around but far away from the triangular libration points .Two special quasi-periodic orbits around each triangular libration points L4 , L5 in the Earth-Moon sys-tem perturbed by Sun are gain , and the stable orbits discussed in this work are ideal places for space colonies because no orbit control is needed. These stable orbits can also be used as nominal orbits for space VLBI (Very Long Baseline Interferometry) stations. The two stations can also form baselines with stations on the Earth and the Moon, or with stations located around another TLP. Due to the long distance between the stations, the observation precision can be greatly enhanced compared with the VLBI stations on the Earth. Such a VLBI constellation not only can advance the radio astronomy, but also can be used as a navigation system for human activities in the Earth-Moon system and even in the solar system. This paper will focus on the navigation constellation coverage issues, and the orbit determination accuracy problems within the Earth-Moon sys-tem and interplanetary space.

  6. Spacecraft Charging Issues for Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Buhler, Janessa L.; Minow, Joseph I.; Trout, Dawn H.

    2014-01-01

    Spacecraft charging is well known threat to successful long term spacecraft operations and instrument reliability in orbits that spend significant time in hot electron environments. In recent years, spacecraft charging has increasingly been recognized as a potentially significant engineering issue for launch vehicles used to deploy spacecraft using (a) low Earth orbit (LEO), high inclination flight trajectories that pass through the auroral zone, (b) geostationary transfer orbits that require exposures to the hot electron environments in the Earths outer radiation belts, and (c) LEO escape trajectories using multiple phasing orbits through the Earths radiation belts while raising apogee towards a final Earth escape geometry. Charging becomes an issue when significant areas of exposed insulating materials or ungrounded conductors are used in the launch vehicle design or the payload is designed for use in a benign charging region beyond the Earths magnetosphere but must survive passage through the strong charging regimes of the Earths radiation belts. This presentation will first outline the charging risks encountered on typical launch trajectories used to deploy spacecraft into Earth orbit and Earth escape trajectories. We then describe the process used by NASAs Launch Services Program to evaluate when surface and internal charging is a potential risk to a NASA mission. Finally, we describe the options for mitigating charging risks including modification of the launch vehicle andor payload design and controlling the risk through operational launch constraints to avoid significant charging environments.

  7. Electromagnetic image-guided orbital decompression: technique, principles, and preliminary experience with 6 consecutive cases.

    PubMed

    Servat, Juan J; Elia, Maxwell Dominic; Gong, Dan; Manes, R Peter; Black, Evan H; Levin, Flora

    2014-12-01

    To assess the feasibility of routine use of electromagnetic image guidance systems in orbital decompression. Six consecutive patients underwent stereotactic-guided three wall orbital decompression using the novel Fusion ENT Navigation System (Medtronic), a portable and expandable electromagnetic guidance system with multi-instrument tracking capabilities. The system consists of the Medtronic LandmarX System software-enabled computer station, signal generator, field-generating magnet, head-mounted marker coil, and surgical tracking instruments. In preparation for use of the LandmarX/Fusion protocol, all patients underwent preoperative non-contrast CT scan from the superior aspect of the frontal sinuses to the inferior aspect of the maxillary sinuses that includes the nasal tip. The Fusion ENT Navigation System (Medtronic™) was used in 6 patients undergoing maximal 3-wall orbital decompression for Graves' orbitopthy after a minimum of six months of disease inactivity. Preoperative Hertel exophthalmometry measured more than 27 mm in all patients. The navigation system proved to be no more difficult technically than the traditional orbital decompression approach. Electromagnetic image guidance is a stereotactic surgical navigation system that provides additional intraoperative flexibility in orbital surgery. Electromagnetic image-guidance offers the ability to perform more aggressive orbital decompressions with reduced risk.

  8. Close up view of the Orbiter Discovery in the Orbiter ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Close up view of the Orbiter Discovery in the Orbiter Processing Facility at Kennedy Space Center. The view is a detail of the aft, starboard landing gear and a general view of the Thermal Protection System tiles around the landing-gear housing. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  9. Long-Term Stability of Planets in the Alpha Centauri System

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack; Quarles, Billy

    2015-01-01

    The alpha Centauri system is billions of years old, so planets are only expected to be found in regions where their orbits are long-lived. We evaluate the extent of the regions within the alpha Centauri AB star system where small planets are able to orbit for billion-year timescales, and we map the positions in the sky plane where planets on stable orbits about either stellar component may appear. We confirm the qualitative results of Wiegert & Holman (Astron. J. 113, 1445, 1997) regarding the approximate size of the regions of stable orbits of a single planet, which are larger for retrograde orbits relative to the binary than for pro-grade orbits. Additionally, we find that mean motion resonances with the binary orbit leave an imprint on the limits of orbital stability, and the effects of the Lidov-Kozai mechanism are also readily apparent. Overall, orbits of a single planet in the habitable zones near the plane of the binary are stable, whereas high-inclination orbits are short-lived. However, even well within regions where single planets are stable, multiple planet systems must be significantly more widely-spaced than they need to be around an isolated star in order to be long-lived.

  10. Evolution of the Space Station Robotic Manipulator

    NASA Technical Reports Server (NTRS)

    Razvi, Shakeel; Burns, Susan H.

    2007-01-01

    The Space Station Remote Manipulator System (SSRMS), Canadarm2, was launched in 2001 and deployed on the International Space Station (ISS). The Canadarm2 has been instrumental in ISS assembly and maintenance. Canadarm2 shares its heritage with the Space Shuttle Arm (Canadarm). This article explores the evolution from the Shuttle Canadarm to the Space Station Canadarm2 design, which incorporates a 7 degree of freedom design, larger joints, and changeable operating base. This article also addresses phased design, redundancy, life and maintainability requirements. The design of Canadarm2 meets unique ISS requirements, including expanded handling capability and the ability to be maintained on orbit. The size of ISS necessitated a mobile manipulator, resulting in the unique capability of Canadarm2 to relocate by performing a walk off to base points located along the Station, and interchanging the tip and base of the manipulator. This provides the manipulator with reach and access to a large part of the Station, enabling on-orbit assembly of the Station and providing support to Extra-Vehicular Activity (EVA). Canadarm2 is evolving based on on-orbit operational experience and new functionality requirements. SSRMS functionality is being developed in phases to support evolving ISS assembly and operation as modules are added and the Station becomes more complex. Changes to sustaining software, hardware architecture, and operations have significantly enhanced SSRMS capability to support ISS mission requirements. As a result of operational experience, SSRMS changes have been implemented for Degraded Joint Operations, Force Moment Sensor Thermal Protection, Enabling Ground Controlled Operations, and Software Commutation. Planned Canadarm2 design modifications include: Force Moment Accommodation, Smart Safing, Separate Safing, and Hot Backup. In summary, Canadarm2 continues to evolve in support of new ISS requirements and improved operations. It is a tribute to the design that this evolution can be accomplished while conducting critical on-orbit operations with minimal hardware changes.

  11. 75 FR 6251 - Notice of Application for Approval of Discontinuance or Modification of a Railroad Signal System...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-08

    ... Discontinuance or Modification of a Railroad Signal System or Relief From the Requirements of Title 49 Code of... approval for the discontinuance or modification of the signal system or relief from the requirements of 49... Company (BNSF) seeks approval of the proposed modification to the traffic control signal system over the...

  12. Design and Proto-Flight Test Strategy for a Microscale Solar Thermal Engine

    NASA Astrophysics Data System (ADS)

    Kennedy, F. G.; Palmer, P.; Gibbon, D.

    2002-01-01

    The authors have previously shown that a micro-scale solar thermal engine, using storable monopropellants (e.g., water, ammonia, or hydrazine) and simplified subsystems, augments microsatellite capabilities by permitting velocity changes on the order of 1,500-3,000 m/s. Small satellites have long been seen as "confined" to limited roles in Low Earth Orbit (LEO). Adding significant propulsive capability opens up new roles and missions--among these, communications in geosynchronous earth orbit (GEO), as well as lunar orbit insertion and near-earth asteroid flybys. Transfer times range from as little as 30-40 days (for Geosynchronous Transfer Orbit to GEO) to 275 days for selected near-earth object encounters. This is accomplished by performing moderate thrust (~5 N) firings of the solar thermal engine at perigee and/or apogee. This paper will briefly review benchmark missions and preliminary design choices, concentrating on the selected detailed design and its ramifications for testing and spacecraft operational use. The solar thermal propulsion system is to be built as a proto-qualification/proto-flight unit (i.e., tested to qualification levels and subsequently used in on-orbit operations). This will minimize the number of experimental iterations prior to flight and reduce overall development cost. The testing program will include acoustic, sinusoidal, and random vibration tests, in line with Ariane 5's Ariane Structure for Auxiliary Payloads (ASAP) requirements. As several SSTL enhanced microsatellites have flown aboard Ariane, these figures represent excellent baseline values for the test campaign. Additionally, the solar thermal engine will be constructed so as to ensure compatibility with existing host spacecraft operational protocols. SSTL ground operations are "autonomous and self-checking," requiring the equivalent of only several operators per day to manage numerous small satellite passes. It is important that an advanced propulsion system not compromise the existing operational paradigm by requiring significantly increased oversight at the satellite ground station. Imposing significant requirements on the host satellite--stringent pointing, an added command and telemetry burden, substantial power augmentation, or severe structural modifications--could make a prima facie "useful" system worthless to the owner and/or operator. The authors will describe some of the creative solutions used to minimize these imposed requirements, simplifying the satellite designer's task. The result of this activity is a low-cost, two-year test program that is intended to result in a fully qualified flight-ready solar thermal engine, prepared for integration and launch no later than 2005. The views expressed in this article are those of the authors and do not reflect the official policy or position of the United States Air Force, Department of Defense, or the U.S. Government.

  13. Nuclear reactor power for a space-based radar. SP-100 project

    NASA Technical Reports Server (NTRS)

    Bloomfield, Harvey; Heller, Jack; Jaffe, Leonard; Beatty, Richard; Bhandari, Pradeep; Chow, Edwin; Deininger, William; Ewell, Richard; Fujita, Toshio; Grossman, Merlin

    1986-01-01

    A space-based radar mission and spacecraft, using a 300 kWe nuclear reactor power system, has been examined, with emphasis on aspects affecting the power system. The radar antenna is a horizontal planar array, 32 X 64 m. The orbit is at 61 deg, 1088 km. The mass of the antenna with support structure is 42,000 kg; of the nuclear reactor power system, 8,300 kg; of the whole spacecraft about 51,000 kg, necessitating multiple launches and orbital assembly. The assembly orbit is at 57 deg, 400 km, high enough to provide the orbital lifetime needed for orbital assembly. The selected scenario uses six Shuttle launches to bring the spacecraft and a Centaur G upper-stage vehicle to assembly orbit. After assembly, the Centaur places the spacecraft in operational orbit, where it is deployed on radio command, the power system started, and the spacecraft becomes operational. Electric propulsion is an alternative and allows deployment in assembly orbit, but introduces a question of nuclear safety.

  14. SARSAT: A rescue system for ships and airplanes

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The SARSAT rescue system is described and alternative systems discussed, with SARSAT functioning as either independent satellite within an emergency call system or as an additional search and rescue payload of another satellite system. Geostationary and polar orbits are compared. A low cost SARSAT rescue system utilizing four satellites in a quasi solar, sun synchronized orbit at 1000 kilometers is proposed. Three multiple start satellites in a 57 degree orbit, with a fourth satellite in reserve at a lower orbit are described. Alternative transport systems are discussed and a recommended time table from project approval to launch is given.

  15. Orbiter CIU/IUS communications hardware evaluation

    NASA Technical Reports Server (NTRS)

    Huth, G. K.

    1979-01-01

    The DOD and NASA inertial upper stage communication system design, hardware specifications and interfaces were analyzed to determine their compatibility with the Orbiter payload communications equipment (Payload Interrogator, Payload Signal Processors, Communications Interface Unit, and the Orbiter operational communications equipment (the S-Band and Ku-band systems). Topics covered include (1) IUS/shuttle Orbiter communications interface definition; (2) Orbiter avionics equipment serving the IUS; (3) IUS communication equipment; (4) IUS/shuttle Orbiter RF links; (5) STDN/TDRS S-band related activities; and (6) communication interface unit/Orbiter interface issues. A test requirement plan overview is included.

  16. Space Transfer Concepts and Analyses for Exploration Missions. Technical Directive 12: Beamed Power Systems Study

    NASA Technical Reports Server (NTRS)

    Eder, D.

    1992-01-01

    Parametric models were constructed for Earth-based laser powered electric orbit transfer from low Earth orbit to geosynchronous orbit. These models were used to carry out performance, cost/benefit, and sensitivity analyses of laser-powered transfer systems including end-to-end life cycle cost analyses for complete systems. Comparisons with conventional orbit transfer systems were made indicating large potential cost savings for laser-powered transfer. Approximate optimization was done to determine best parameter values for the systems. Orbit transfer flights simulations were conducted to explore effects of parameters not practical to model with a spreadsheet. The simulations considered view factors that determine when power can be transferred from ground stations to an orbit transfer vehicle and conducted sensitivity analyses for numbers of ground stations, Isp including dual-Isp transfers, and plane change profiles. Optimal steering laws were used for simultaneous altitude and plane change. Viewing geometry and low-thrust orbit raising were simultaneously simulated. A very preliminary investigation of relay mirrors was made.

  17. Exact relations between homoclinic and periodic orbit actions in chaotic systems

    NASA Astrophysics Data System (ADS)

    Li, Jizhou; Tomsovic, Steven

    2018-02-01

    Homoclinic and unstable periodic orbits in chaotic systems play central roles in various semiclassical sum rules. The interferences between terms are governed by the action functions and Maslov indices. In this article, we identify geometric relations between homoclinic and unstable periodic orbits, and derive exact formulas expressing the periodic orbit classical actions in terms of corresponding homoclinic orbit actions plus certain phase space areas. The exact relations provide a basis for approximations of the periodic orbit actions as action differences between homoclinic orbits with well-estimated errors. This enables an explicit study of relations between periodic orbits, which results in an analytic expression for the action differences between long periodic orbits and their shadowing decomposed orbits in the cycle expansion.

  18. Geologic Map of MTM -40277, -45277, -40272, and -45272 Quadrangles, Eastern Hellas Planitia Region of Mars

    USGS Publications Warehouse

    Bleamaster, Leslie F.; Crown, David A.

    2010-01-01

    Hellas Planitia comprises the floor deposits of the Hellas basin, more than 2,000 km across and 8 km deep, which is located in the southern hemisphere's cratered highlands and is the largest well-preserved impact structure on the Martian surface. The circum-Hellas highlands represent a significant percentage of the southern hemisphere of Mars and have served as a locus for volcanic and sedimentary activity throughout Martian geologic time. Hellas basin topography has had a long-lasting influence, acting as Mars' deepest and second largest depositional sink, as a source for global dust storms, and as a forcing agent on southern hemisphere atmospheric circulation. The region lies in the Martian mid-latitude zone where geomorphic indicators of past, and possibly contemporary, ground ice are prominent. The highlands north of the basin show concentrations of Noachian valley networks, and those to the east show prominent lobate debris aprons that are considered to be geomorphic indicators of ground ice. Several studies have proposed that Hellas itself was the site of extensive glacial and lacustrine activity. Recent analyses of mineralogical information from Mars Express' OMEGA (Observatoire pour la Mineralogie, l'Eau les Glaces et l'Activite) and Mars Reconnaissance Orbiter's CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) reveal outcrops of hydrated phyllosilicates in the region, strengthening an already strong case for past aqueous activity in and around Hellas basin. Our mapping and evaluation of landforms and materials of the Hellas region from basin rim to floor provides further insight into Martian global climate regimes and into the abundance, distribution, and flux of volatiles through history. Mars Transverse Mercator (MTM) quadrangles -40277, -45277, -45272, and -40272 (lat 37.5 degrees S.-47.5 degrees S., long 270 degrees W.-280 degrees W.) cover the eastern portion of the Hellas basin including the boundary between its floor and rim, the distal portions of Dao and Harmakhis Valles, and the deposits of eastern Hellas Planitia. The geologic mapping, at 1:1,000,000-scale from Viking Orbiter, Thermal Emission Imaging System (THEMIS) infrared (IR) and visible (VIS) wavelength, and Mars Orbiter Camera (MOC) narrow-angle images, combined with Mars Orbiter Laser Altimeter (MOLA) topographic data, characterizes the geologic materials and processes that have shaped this region. In particular, the mapping helps to evaluate landforms and deposits resulting from modification of highland terrains by volatile-driven degradation. This mapping study builds on previous mapping in Hellas Planitia and to the east and facilitates comparisons between the geologic history of the east rim, the remainder of the rim, and Hellas Planitia. Specific objectives of our mapping are (1) to reconstruct fluvial systems that dissect the Hellas rim, (2) to characterize the extensions of Dao and Harmakhis Valles onto the basin floor and to identify, if present, sediments these canyons contributed to Hellas Planitia from the rim, and (3) to investigate the mode of origin, age, and history of modification of the boundary between the east rim and Hellas Planitia.

  19. Motion of the moonlet in the binary system 243 Ida

    NASA Astrophysics Data System (ADS)

    Lan, L.; Ni, Y.; Jiang, Y.; Li, J.

    2018-02-01

    The motion of the moonlet Dactyl in the binary system 243 Ida is investigated in this paper. First, periodic orbits in the vicinity of the primary are calculated, including the orbits around the equilibrium points and large-scale orbits. The Floquet multipliers' topological cases of periodic orbits are calculated to study the orbits' stabilities. During the continuation of the retrograde near-circular orbits near the equatorial plane, two period-doubling bifurcations and one Neimark-Sacker bifurcation occur one by one, leading to two stable regions and two unstable regions. Bifurcations occur at the boundaries of these regions. Periodic orbits in the stable regions are all stable, but in the unstable regions are all unstable. Moreover, many quasi-periodic orbits exist near the equatorial plane. Long-term integration indicates that a particle in a quasi-periodic orbit runs in a space like a tire. Quasi-periodic orbits in different regions have different styles of motion indicated by the Poincare sections. There is the possibility that moonlet Dactyl is in a quasi-periodic orbit near the stable region I, which is enlightening for the stability of the binary system.

  20. KOI2138 -- a Spin-Orbit Aligned Intermediate Period Super-Earth

    NASA Astrophysics Data System (ADS)

    Barnes, Jason W.

    2015-11-01

    A planet's formation and evolution are encoded in spin-orbit alignment -- the planet's inclination relative to its star's equatorial plane. While the solar system's spin-orbit aligned planets indicate our own relatively quiescent history, many close-in giant planets show significant misalignment. Some planets even orbit retrograde! Hot Jupiters, then, have experienced fundamentally different histories than we experienced here in the solar system. In this presentation, I will show a new determination of the spin-orbit alignment of 2.1 REarth exoplanet candidate KOI2138. KOI2138 shows a gravity-darkened transit lightcurve that is consistent with spin-orbit alignment. This measurement is important because the only other super-Earth with an alignment determination (55 Cnc e, orbit period 0.74 days) is misaligned. With an orbital period of 23.55 days, KOI2138 is far enough from its star to avoid tidal orbit evolution. Therefore its orbit is likely primordial, and hence it may represent the tip of an iceberg of terrestrial, spin-orbit aligned planets that have histories that more closely resemble that of the solar system's terrestrial planets.

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