Development of an Online Exoplanet Course for In-Service Teachers

NASA Astrophysics Data System (ADS)

Barringer, Daniel; Palma, Christopher

2016-01-01

The Earth and Space Science Partnership (ESSP) is a collaboration among Penn State scientists, science educators and seven school districts across Pennsylvania. Penn State also offers through its fully online World Campus the opportunity for In-Service science teachers to earn an M.Ed. degree in Earth Science, and we currently offer a required online astronomy course for that program. We have previously presented descriptions of how have incorporated research-based pedagogical practices into ESSP-sponsored workshops for in-service teachers (Palma et al. 2013) and into a pilot section of introductory astronomy for non-science majors (Palma et al. 2014). In this presentation, we detail the design and development of a new online astronomy course to be offered through the M.Ed. Earth Science degree program. This course also uses a coherent content storyline approach (Roth et al. 2011), and will engage the teachers in investigations using authentic data within the Claims Evidence Reasoning framework (McNeill & Krajcik 2012). The course theme will be exploring exoplanets in order to show how these objects have forced us to reconsider some ideas in our model for the formation of the Solar System, which is a disciplinary core idea identified in the Next Generation Science Standards (citation). Course materials will be made available through Penn State's open courseware initiative and will be promoted to teachers throughout PA through the Pennsylvania Earth Science Teachers' Association (PAESTA). We gratefully acknowledge support from the NSF MSP program award DUE#0962792.

The Orbiting Carbon Observatory: NASA's First Dedicated Carbon Dioxide Mission

NASA Technical Reports Server (NTRS)

Crisp, D.

2008-01-01

The Orbiting Carbon Observatory is scheduled for launch from Vandenberg Air Force Base in California in January 2009. This Earth System Science Pathfinder (ESSP) mission carries and points a single instrument that incorporates 3 high-resolution grating spectrometers designed to measure the absorption of reflected sunlight by near-infrared carbon dioxide (CO2) and molecular oxygen bands. These spectra will be analyzed to retrieve estimates of the column-averaged CO2 dry air mole fraction, X(sub CO2). Pre-flight qualification and calibration tests completed in early 2008 indicate that the instrument will provide high quality X(sub CO2) data. The instrument was integrated into the spacecraft, and the completed Observatory was qualified and tested during the spring and summer of 2008, in preparation for delivery to the launch site in the fall of this year. The Observatory will initially be launched into a 635 km altitude, near-polar orbit. The on-board propulsion system will then raise the orbit to 705 km and insert OCO into the Earth Observing System Afternoon Constellation (A-Train). The first routine science observations are expected about 45 days after launch. Calibrated spectral radiances will be archived starting about 6 months later. An exploratory X(sub CO2) product will be validated and then archived starting about 3 months after that.

The Orbiting Carbon Observatory: NASA's first dedicated carbon dioxide mission

NASA Astrophysics Data System (ADS)

Crisp, D.

2008-10-01

The Orbiting Carbon Observatory is scheduled for launch from Vandenberg Air Force Base in California in January 2009. This Earth System Science Pathfinder (ESSP) mission carries and points a single instrument that incorporates 3 high-resolution grating spectrometers designed to measure the absorption of reflected sunlight by near-infrared carbon dioxide (CO2) and molecular oxygen bands. These spectra will be analyzed to retrieve estimates of the column-averaged CO2 dry air mole fraction, XCO2. Pre-flight qualification and calibration tests completed in early 2008 indicate that the instrument will provide high quality XCO2 data. The instrument was integrated into the spacecraft, and the completed Observatory was qualified and tested during the spring and summer of 2008, in preparation for delivery to the launch site in the fall of this year. The Observatory will initially be launched into a 635 km altitude, near-polar orbit. The on-board propulsion system will then raise the orbit to 705 km and insert OCO into the Earth Observing System Afternoon Constellation (A-Train). The first routine science observations are expected about 45 days after launch. Calibrated spectral radiances will be archived starting about 6 months later. An exploratory XCO2 product will be validated and then archived starting about 3 months after that.

Using SCIAMACHY and Ground-based FTS Measurements to Test the OCO X(sub CO2) Retrieval and Validation Approach

NASA Technical Reports Server (NTRS)

Boesch, Hartmut; Toon, G.; Sen, B; Li, Q. B.; Salawitch, R.; Miller, C.; Crisp, D.; Washenfelder, R.; Wennberg, P.; Natraj, V.;

Observing relationships between lightning and cloud profiles by means of a satellite-borne cloud radar

NASA Astrophysics Data System (ADS)

Buiat, Martina; Porcù, Federico; Dietrich, Stefano

2017-01-01

Cloud electrification and related lightning activity in thunderstorms have their origin in the charge separation and resulting distribution of charged iced particles within the cloud. So far, the ice distribution within convective clouds has been investigated mainly by means of ground-based meteorological radars. In this paper we show how the products from Cloud Profiling Radar (CPR) on board CloudSat, a polar satellite of NASA's Earth System Science Pathfinder (ESSP), can be used to obtain information from space on the vertical distribution of ice particles and ice content and relate them to the lightning activity. The analysis has been carried out, focusing on 12 convective events over Italy that crossed CloudSat overpasses during significant lightning activity. The CPR products considered here are the vertical profiles of cloud ice water content (IWC) and the effective radius (ER) of ice particles, which are compared with the number of strokes as measured by a ground lightning network (LINET). Results show a strong correlation between the number of strokes and the vertical distribution of ice particles as depicted by the 94 GHz CPR products: in particular, cloud upper and middle levels, high IWC content and relatively high ER seem to be favourable contributory causes for CG (cloud to ground) stroke occurrence.

JWST Pathfinder Telescope Risk Reduction Cryo Test Program

NASA Technical Reports Server (NTRS)

Matthews, Gary W.; Scorse, Thomas R.; Spina, John A.; Noel, Darin M.; Havey, Keith A., Jr.; Huguet, Jesse A.; Whitman, Tony L.; Wells, Conrad; Walker, Chanda B.; Lunt, Sharon;

Pathfinder Innovation Projects

EPA Pesticide Factsheets

The Pathfinder program supports high-risk, high-reward research ideas with funding and staff time. The goal is to feed a culture of innovation in the Agency and integrate innovative ideas in EPA research programs.

Pathfinder Innovation Projects: Awardees 2015

EPA Pesticide Factsheets

The Pathfinder program supports high-risk, high-reward research ideas with funding and staff time. The goal is to feed a culture of innovation in the Agency and integrate innovative ideas in EPA research programs.

Pathfinder Innovation Projects: Awardees 2016

EPA Pesticide Factsheets

The Pathfinder program supports high-risk, high-reward research ideas with funding and staff time. The goal is to feed a culture of innovation in the Agency and integrate innovative ideas in EPA research programs.

A Coherent Content Storyline Approach for Introductory Astronomy

NASA Astrophysics Data System (ADS)

Palma, Christopher; Flarend, A.; McDonald, S.; Kregenow, J. M.

2014-01-01

The Earth and Space Science Partnership (ESSP) is a collaboration among Penn State scientists, science educators and seven school districts across Pennsylvania. Part of the multi-faceted ESSP effort includes revising the curriculum of university science classes known to be taken by large numbers of elementary pre-service teachers. By adopting research-based pedagogical approaches in our courses, we hope to expose these pre-service teachers to excellent examples of science teaching. In this presentation, we will discuss changes made in a pilot study to one section of our introductory astronomy survey course. There have been many articles published in the Astronomy Education Review and elsewhere that detail research-based pedagogical practices for introductory astronomy courses. Many of those practices (such as from the Center for Astronomy Education) have been incorporated into introductory astronomy courses at Penn State. However, our work with middle-grades teachers in the ESSP project is based on two key practices: a Claims, Evidence, and Reasoning (CER) framework (McNeill & Krajcik 2012) and a coherent science content storyline (Roth,et. al., 2011). As a first step in modeling these practices in our University courses, we reorganized our Astro course using a content storyline approach. We plan to incorporate CER activities into the course next year that advance the storyline described. In this poster, we present the storyline developed by our team, which we believe was successful in its pilot, and was built around a conceptually coherent presentation of the diverse set of phenomena typical of an introductory astronomy course. We adopted as our main learning goal a statement based on the cosmological principle that the physical laws throughout the Universe are identical everywhere. In addition, we organized the class schedule to connect the work done in each class to this storyline. We suggest that a coherent content storyline is a useful tool for others who teach broad survey astronomy courses similar to ours at Penn State. We gratefully acknowledge support from the NSF MSP program award DUE#0962792.

NASA's Chemical Transfer Propulsion Program for Pathfinder

NASA Technical Reports Server (NTRS)

Hannum, Ned P.; Berkopec, Frank D.; Zurawski, Robert L.

1989-01-01

Pathfinder is a research and technology project, with specific deliverables, initiated by the National Aeronautics and Space Administration (NASA) which will strengthen the technology base of the United States civil space program in preparation for future space exploration missions. Pathfinder begins in Fiscal Year 1989, and is to advance a collection of critical technologies for these missions and ensure technology readiness for future national decisions regarding exploration of the solar system. The four major thrusts of Pathfinder are: surface exploration, in-space operations, humans-in-space, and space transfer. The space transfer thrust will provide the critical technologies needed for transportation to, and return from, the Moon, Mars, and other planets in the solar system, as well as for reliable and cost-effective Earth-orbit operations. A key element of this thrust is the Chemical Transfer Propulsion program which will provide the propulsion technology for high performance, liquid oxygen/liquid hydrogen expander cycle engines which may be operated and maintained in space. Described here are the program overview including the goals and objectives, management, technical plan, and technology transfer for the Chemical Transfer Propulsion element of Pathfinder.

Mars Pathfinder Rover-Lewis Research Center Technology Experiments Program

NASA Technical Reports Server (NTRS)

Stevenson, Steven M.

1997-01-01

An overview of NASA's Mars Pathfinder Program is given and the development and role of three technology experiments from NASA's Lewis Research Center and carried on the Mars Pathfinder rover is described. Two recent missions to Mars were developed and managed by the Jet Propulsion Laboratory, and launched late last year: Mars Global Surveyor in November 1996 and Mars Pathfinder in December 1996. Mars Global Surveyor is an orbiter which will survey the planet with a number of different instruments, and will arrive in September 1997, and Mars Pathfinder which consists of a lander and a small rover, landing on Mars July 4, 1997. These are the first two missions of the Mars Exploration Program consisting of a ten year series of small robotic martian probes to be launched every 26 months. The Pathfinder rover will perform a number of technology and operational experiments which will provide the engineering information necessary to design and operate more complex, scientifically oriented surface missions involving roving vehicles and other machinery operating in the martian environment. Because of its expertise in space power systems and technologies, space mechanisms and tribology, Lewis Research Center was asked by the Jet Propulsion Laboratory, which is heading the Mars Pathfinder Program, to contribute three experiments concerning the effects of the martian environment on surface solar power systems and the abrasive qualities of the Mars surface material. In addition, rover static charging was investigated and a static discharge system of several fine Tungsten points was developed and fixed to the rover. These experiments and current findings are described herein.

Software Aids Visualization Of Mars Pathfinder Mission

NASA Technical Reports Server (NTRS)

Weidner, Richard J.

1996-01-01

Report describes Simulator for Imager for Mars Pathfinder (SIMP) computer program. SIMP generates "virtual reality" display of view through video camera on Mars lander spacecraft of Mars Pathfinder mission, along with display of pertinent textual and graphical data, for use by scientific investigators in planning sequences of activities for mission.

Pathfinder-Plus takes off on flight in Hawaii

NASA Technical Reports Server (NTRS)

1998-01-01

Pathfinder-Plus on a flight over Hawaii in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

Pathfinder-Plus on flight in Hawaii

NASA Technical Reports Server (NTRS)

1998-01-01

Pathfinder-Plus on a flight over Hawaii in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

Pathfinder-Plus on a flight over Hawaiian island N'ihau

NASA Technical Reports Server (NTRS)

1998-01-01

Pathfinder-Plus on a flight over the Hawaiian island of N'ihau in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

Pathfinder-Plus on flight over Hawaiian island N'ihau

NASA Technical Reports Server (NTRS)

1998-01-01

Pathfinder-Plus on a flight over the Hawaiian island of N'ihau in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

Pathfinder-Plus on flight near Hawaiian island N'ihau

NASA Technical Reports Server (NTRS)

1998-01-01

Pathfinder-Plus on a flight with the Hawaiian island of N'ihau in the background. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

Pathfinder-Plus on flight over Hawaii

NASA Technical Reports Server (NTRS)

1998-01-01

Pathfinder-Plus flying over the Hawaiian Islands in 1998 with Ni'ihau Island in the background. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

Pathfinder-Plus on flight over Hawaii

NASA Technical Reports Server (NTRS)

1998-01-01

Pathfinder-Plus on flight over Hawaii. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

Pathfinder-Plus on a flight in Hawaii

NASA Technical Reports Server (NTRS)

1998-01-01

Pathfinder-Plus on a flight in 1998 over Hawaiian waters. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

Pathfinder-Plus on flight over Hawaiian Islands

NASA Technical Reports Server (NTRS)

1998-01-01

Pathfinder-Plus on flight over Hawaiian Islands in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

Pathfinder technologies for bold new missions. [U.S. research and development program for space exploration

NASA Technical Reports Server (NTRS)

Sadin, Stanley R.; Rosen, Robert

1987-01-01

Project Pathfinder is a proposed U.S. Space Research and Technology program intended to enable bold new missions of space exploration. Pathfinder continues the advancement of technological capabilities and extends the foundation established under the Civil Space Technology Initiative, CSTI. By filling critical technological gaps, CSTI enhances access to Earth orbit and supports effective operations and science missions therein. Pathfinder, with a longer-term horizon, looks to a future that builds on Shuttle and Space Station and addresses technologies that support a range of exploration missions including: a return to the Moon to build an outpost; piloted missions to Mars; and continued scientific exploration of Earth and the other planets. The program's objective is to develop, within reasonable time frames, those emerging and innovative technologies that will make possible both new and enhanced missions and system concepts.

Pathfinder-Plus on flight over Hawaiian Islands, with N'ihau and Lehua in the background

NASA Technical Reports Server (NTRS)

1998-01-01

Pathfinder-Plus on flight over Hawaiian Islands, with N'ihau and Lehua in the background. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50,000 feet. Major activities of Pathfinder Plus' Hawaiian flights included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters, and assessment of coral reef health. Pathfinder science activities were coordinated by NASA's Ames Research Center, Mountain View, California, and included researchers from the University of Hawaii and the University of California. Pathfinder is part of NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program managed by NASA's Dryden Flight Research Center, Edwards, California. Pathfinder and Pathfinder Plus were designed, built, and operated by AeroVironment, Inc., Monrovia, California. Pathfinder had a 98.4-foot wing span and weighed 560 pounds. Pathfinder Plus has a 121-foot wing span and weighs about 700 pounds. Pathfinder was powered by six electric motors while Pathfinder Plus has eight. Pathfinder's solar arrays produced approximately 8,000 watts of power while Pathfinder Plus' solar arrays produce about 12,500 watts of power. Both Pathfinder aircraft were built primarily of composites, plastic, and foam.

Pathfinders and Problem Solving: Comparative Effects of Two Cognitive-Behavioral Programs among Men and Women Offenders in Community and Prison

ERIC Educational Resources Information Center

Spiropoulos, Georgia V.; Spruance, Lisa; Van Voorhis, Patricia; Schmitt, Michelle M.

2005-01-01

The effects of "Problem Solving" (Taymans & Parese, 1998) are compared across small diversion and prison samples for men and women. A second program, "Pathfinders" (Hansen, 1993), was compared to the Problem Solving program among incarcerated women offenders to determine whether its focus upon empowerment and relationships enhanced the effects of…

Validation of the Version 1 NOAA/NASA Pathfinder Sea Surface Temperature Data Set

NASA Technical Reports Server (NTRS)

Smith, Elizabeth A.

1998-01-01

A high-resolution, global satellite-derived sea surface temperature (SST) data set called Pathfinder, from the Advanced Very High Resolution Radiometer (AVHRR) aboard the NOAA Polar Orbiters, is available from the Jet Propulsion Laboratory Physical Oceanography Distributed Active Archive Center (JPL PO.DAAC). Suitable for research as well as education, the Pathfinder SST data set is a result of a collaboration between the National Oceanographic and Atmospheric Administration (NOAA), the National Aeronautics and Space Administration (NASA) and investigators at several universities. NOAA and NASA are the sponsors of the Pathfinder Program, which takes advantage of currently archived Earth science data from satellites. Where necessary, satellite sensors have been intercalibrated, algorithms improved and processing procedures revised, in order to produce long time-series, global measurements of ocean, land and atmospheric properties necessary for climate research. Many Pathfinder data sets are available to researchers now, nearly a decade before the first launch of NASA's Earth Observing System (EOS). The lessons learned from the Pathfinder programs will facilitate the processing and management of terabytes of data from EOS. The Oceans component of Pathfinder has undertaken to reprocess all Global Area Coverage (GAC) data acquired by the 5-channel AVHRRs since 1981. The resultant data products are consistent and stably calibrated [Rao, 1993a, Rao, 1993b, Brown et al., 1993], Earth-gridded SST fields at a variety of spatial and temporal resolutions.

Airbag retraction

NASA Technical Reports Server (NTRS)

1997-01-01

This image shows that the Mars Pathfinder airbags have been successfully retracted, allowing safe deployment of the rover ramps. The Sojourner rover is at lower right, and rocks are visible in the background. Mars Pathfinder landed successfully on the surface of Mars today at 10:07 a.m. PDT.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Predictive Validity of Measures of the Pathfinder Scaling Algorithm on Programming Performance: Alternative Assessment Strategy for Programming Education

ERIC Educational Resources Information Center

Lau, Wilfred W. F.; Yuen, Allan H. K.

2009-01-01

Recent years have seen a shift in focus from assessment of learning to assessment for learning and the emergence of alternative assessment methods. However, the reliability and validity of these methods as assessment tools are still questionable. In this article, we investigated the predictive validity of measures of the Pathfinder Scaling…

Airbag retraction

NASA Technical Reports Server (NTRS)

1997-01-01

This image shows that the Mars Pathfinder airbags have been successfully retracted, allowing safe deployment of the rover ramps. The Sojourner rover, still in its deployed position, is at center image, and rocks are visible in the background. Mars Pathfinder landed successfully on the surface of Mars today at 10:07 a.m. PDT.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Pathfinder aircraft flight #1

NASA Image and Video Library

1996-11-19

The Pathfinder solar-powered research aircraft settles in for landing on the bed of Rogers Dry Lake at the Dryden Flight Research Center, Edwards, California, after a successful test flight Nov. 19, 1996. The ultra-light craft flew a racetrack pattern at low altitudes over the flight test area for two hours while project engineers checked out various systems and sensors on the uninhabited aircraft. The Pathfinder was controlled by two pilots, one in a mobile control unit which followed the craft, the other in a stationary control station. Pathfinder, developed by AeroVironment, Inc., is one of several designs being evaluated under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program.

Pathfinder aircraft taking off - setting new solar powered altitude record

NASA Image and Video Library

1995-09-11

The Pathfinder solar-powered remotely piloted aircraft climbs to a record-setting altitude of 50,567 feet during a flight Sept. 11, 1995, at NASA's Dryden Flight Research Center, Edwards, California. The flight was part of the NASA ERAST (Environmental Research Aircraft and Sensor Technology) program. The Pathfinder was designed and built by AeroVironment Inc., Monrovia, California. Solar arrays cover nearly all of the upper wing surface and produce electricity to power the aircraft's six motors.

Near-field spectral shift of a zero-order Bessel beam scattered from a spherical particle

NASA Astrophysics Data System (ADS)

Chen, Feinan; Li, Jia; Belafhal, Abdelmajid; Chafiq, Abdelghani; Sun, Xiaobing

2018-06-01

Within the accuracy of the first-order Born approximation, expressions are derived for the near-zone spectrum of a zero-order Bessel beam scattered from a spherical particle whose correlation function satisfies a Gaussian distribution. The dependence of the spectral shift and spectral switch of the scattered field on the effective size of the scattering potential (ESSP) are determined by numerical simulations. It is shown that the spectral shift of the scattered field does not occur along the longitudinal propagation direction. Furthermore, when the medium’s ESSP is comparable with the central wavelength of the beam, the spectrum of the scattered field loses the Gaussian distribution and exhibits a blue shift as the reference point sufficiently far away from central origin. These results may have prospective applications in guiding tiny particles when the near-zone spectrums of scattered beams are captured and analyzed.

Pathfinder aircraft in flight

NASA Image and Video Library

1995-07-27

The Pathfinder research aircraft's wing structure was clearly defined as it soared under a clear blue sky during a test flight July 27, 1995, from Dryden Flight Research Center, Edwards, California. The center section and outer wing panels of the aircraft had ribs constructed of thin plastic foam, while the ribs in the inner wing panels are fabricated from lightweight composite material. Developed by AeroVironment, Inc., the Pathfinder was one of several unmanned aircraft being evaluated under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program.

Sojourner, Wedge, & Shark

NASA Technical Reports Server (NTRS)

1997-01-01

This Imager for Mars Pathfinder (IMP) image taken near the end of daytime operations on Sol 50 shows the Sojourner rover between the rocks 'Wedge' (foreground) and 'Shark' (behind rover). The rover successfully deployed its Alpha Proton X-Ray Spectrometer on Shark on Sol 52.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Pathfinder aircraft taking off - setting new solar powered altitude record

NASA Technical Reports Server (NTRS)

1995-01-01

The Pathfinder solar-powered remotely piloted aircraft climbs to a record-setting altitude of 50,567 feet during a flight Sept. 11, 1995, at NASA's Dryden Flight Research Center, Edwards, California. The flight was part of the NASA ERAST (Environmental Research Aircraft and Sensor Technology) program. The Pathfinder was designed and built by AeroVironment Inc., Monrovia, California. Solar arrays cover nearly all of the upper wing surface and produce electricity to power the aircraft's six motors. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

Martian Surface & Pathfinder Airbags

NASA Technical Reports Server (NTRS)

1997-01-01

This image of the Martian surface was taken in the afternoon of Mars Pathfinder's first day on Mars. Taken by the Imager for Mars Pathfinder (IMP camera), the image shows a diversity of rocks strewn in the foreground. A hill is visible in the distance (the notch within the hill is an image artifact). Airbags are seen at the lower right.

The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.' It stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

AVHRR-Based Polar Pathfinder Products: Evaluation, Enhancement, and Transition to MODIS

NASA Technical Reports Server (NTRS)

Fowler, Charles; Maslanik, James; Stone, Robert; Stroeve, Julienne; Emery, William

2001-01-01

The AVHRR-Based Polar Pathfinder (APP) products include calibrated AVHRR channel data, surface temperatures, albedo, satellite scan and solar geometries, and a cloud mask composited into twice- per-day images, and daily averaged fields of sea ice motion, for regions poleward of 50 deg. latitude. Our goals under this grant, in general, are four-fold: 1. To quantify the APP accuracy and sources of error by comparing Pathfinder products with field measurements. 2. To determine the consistency of mean fields and trends in comparison with longer time series of available station data and forecast model output. 3. To investigate the consistency of the products between the different AVHRR instruments over the 1982-present period of the NOAA program. 4. To compare an annual cycle of the AVHRR Pathfinder products with MODIS to establish a baseline for extending Pathfinder-type products into the new ESE period. Year One tasks include intercomparisons of the Pathfinder products with field measurements, testing of algorithm assumptions, collection of field data, and further validation and possible improvement of the multi-sensor ice motion fields. Achievements for these tasks are summarized below.

Rocky terrain & airbags

NASA Technical Reports Server (NTRS)

1997-01-01

An area of very rocky terrain at the Ares Vallis landing site, along with the lander's deflated airbags, were imaged by the Imager for Mars Pathfinder (IMP) before its deployment on Sol 2. The metallic object at the bottom is a bracket for the IMP's release mechanism.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Sojourner's APXS at Shark

NASA Technical Reports Server (NTRS)

1997-01-01

The Sojourner rover is seen next to the rock 'Shark', in this image taken by the Imager for Mars Pathfinder (IMP) near the end of daytime operations on Sol 52. The rover's Alpha Proton X-Ray Spectrometer is deployed against the rock. The rock 'Wedge' is in the foreground.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Pathfinder

NASA Image and Video Library

2004-04-15

This artist's concept depicts the X-34 Demonstrator in flight. Part of the Pathfinder Program, the X-34 was a reusable technology testbed vehicle that was designed and built by the Marshall Space Flight Center to demonstrate technologies that were essential to lowering the cost of access to space. Powered by a LOX and RP-1 liquid Fastrac engine, the X-34 would be capable of speeds up to Mach 8 and altitudes of 250,000-feet. The X-34 program was cancelled in 2001.

Pathfinder

NASA Image and Video Library

2004-04-15

Pictured is the X-34 Demonstrator parked on the runway. Part of the Pathfinder Program, the X-34 was a reusable technology testbed vehicle that was designed and built by the Marshall Space Flight Center to demonstrate technologies that are essential to lowering the cost of access to space. Powered by a LOX and RP-1 liquid Fastrac engine, the X-34 would be capable of speeds up to Mach 8 and altitudes of 250,000-feet. The X-34 program was cancelled in 2001.

Pathfinders: Making a Way from Segregation to Community Life.

ERIC Educational Resources Information Center

O'Brien, Connie Lyle; Mount, Beth; O'Brien, John; Rosen, Fredda

This paper describes the Pathfinders program in New York (New York), which works to facilitate the full integration of adults with developmental disabilities into workplaces and neighborhoods. The paper is organized around the question of whether students graduating from special education can find paid and volunteer work in community settings,…

Modeling to Mars: a NASA Model Based Systems Engineering Pathfinder Effort

NASA Technical Reports Server (NTRS)

Phojanamongkolkij, Nipa; Lee, Kristopher A.; Miller, Scott T.; Vorndran, Kenneth A.; Vaden, Karl R.; Ross, Eric P.; Powell, Bobby C.; Moses, Robert W.

2017-01-01

The NASA Engineering Safety Center (NESC) Systems Engineering (SE) Technical Discipline Team (TDT) initiated the Model Based Systems Engineering (MBSE) Pathfinder effort in FY16. The goals and objectives of the MBSE Pathfinder include developing and advancing MBSE capability across NASA, applying MBSE to real NASA issues, and capturing issues and opportunities surrounding MBSE. The Pathfinder effort consisted of four teams, with each team addressing a particular focus area. This paper focuses on Pathfinder team 1 with the focus area of architectures and mission campaigns. These efforts covered the timeframe of February 2016 through September 2016. The team was comprised of eight team members from seven NASA Centers (Glenn Research Center, Langley Research Center, Ames Research Center, Goddard Space Flight Center IV&V Facility, Johnson Space Center, Marshall Space Flight Center, and Stennis Space Center). Collectively, the team had varying levels of knowledge, skills and expertise in systems engineering and MBSE. The team applied their existing and newly acquired system modeling knowledge and expertise to develop modeling products for a campaign (Program) of crew and cargo missions (Projects) to establish a human presence on Mars utilizing In-Situ Resource Utilization (ISRU). Pathfinder team 1 developed a subset of modeling products that are required for a Program System Requirement Review (SRR)/System Design Review (SDR) and Project Mission Concept Review (MCR)/SRR as defined in NASA Procedural Requirements. Additionally, Team 1 was able to perform and demonstrate some trades and constraint analyses. At the end of these efforts, over twenty lessons learned and recommended next steps have been identified.

Future X Pathfinder: Quick, Low Cost Flight Testing for Tomorrow's Launch Vehicles

NASA Technical Reports Server (NTRS)

London, John, III; Sumrall, Phil

1999-01-01

The DC-X and DC-XA Single Stage Technology flight program demonstrated the value of low cost rapid prototyping and flight testing of launch vehicle technology testbeds. NASA is continuing this important legacy through a program referred to as Future-X Pathfinder. This program is designed to field flight vehicle projects that cost around $100M each, with a new vehicle flying about every two years. Each vehicle project will develop and extensively flight test a launch vehicle technology testbed that will advance the state of the art in technologies directly relevant to future space transportation systems. There are currently two experimental, or "X" vehicle projects in the Pathfinder program, with additional projects expected to follow in the near future. The first Pathfinder project is X-34. X-34 is a suborbital rocket plane capable of flights to Mach 8 and 75 kilometers altitude. There are a number of reusable launch vehicle technologies embedded in the X-34 vehicle design, such as composite structures and propellant tanks, and advanced reusable thermal protection systems. In addition, X-34 is designed to carry experiments applicable to both the launch vehicle and hypersonic aeronautics community. X-34 is scheduled to fly later this year. The second Pathfinder project is the X-37. X-37 is an orbital space plane that is carried into orbit either by the Space Shuttle or by an expendable launch vehicle. X-37 provides NASA access to the orbital and orbital reentry flight regimes with an experimental testbed vehicle. The vehicle will expose embedded and carry-on advanced space transportation technologies to the extreme environments of orbit and reentry. Early atmospheric approach and landing tests of an unpowered version of the X-37 will begin next year, with orbital flights beginning in late 2001. Future-X Pathfinder is charting a course for the future with its growing fleet of low-cost X- vehicles. X-34 and X-37 are leading the assault on high launch costs and enabling the flight testing of technologies that will lead to affordable access to space.

Pathfinder

NASA Image and Video Library

2004-04-15

Pictured is NASA's poster art for the X-34 technology Demonstrator. The X-34 was part of NASA's Pathfinder Program which demonstrated advanced space transportation technologies through the use of flight experiments and experimental vehicles. These technology demonstrators and flight experiments would support the Agency's goal of dramatically reducing the cost of access to space and would define the future of space transportation pushing technology into a new era of space development and exploration at the dawn of the new century. The X-34 program was cancelled in 2001.

Pathfinder

NASA Image and Video Library

2004-04-15

This artist's concept depicts the X-34 Demonstrator sitting on a runway. Part of the Pathfinder Program, the X-34 was a reusable technology testbed vehicle that was designed and built by the Marshall Space Flight Center to demonstrate technologies that were essential to lowering the cost of access to space. Powered by a LOX and RP-1 liquid Fastrac engine, the X-34 would be capable of speeds up to Mach 8 and altitudes of 250,000-feet. The X-34 program was cancelled in 2001.

Pathfinder

NASA Image and Video Library

2004-04-15

This artist's concept depicts the X-34 Demonstrator landing in a dessert. Part of the Pathfinder Program, the X-34 was a reusable technology testbed vehicle that was designed and built by the Marshall Space Flight Center to demonstrate technologies that were essential to lowering the cost of access to space. Powered by a LOX and RP-1 liquid Fastrac engine, the X-34 would be capable of speeds up to Mach 8 and altitudes of 250,000-feet. The X-34 program was cancelled in 2001.

Symbolic PathFinder: Symbolic Execution of Java Bytecode

NASA Technical Reports Server (NTRS)

Pasareanu, Corina S.; Rungta, Neha

2010-01-01

Symbolic Pathfinder (SPF) combines symbolic execution with model checking and constraint solving for automated test case generation and error detection in Java programs with unspecified inputs. In this tool, programs are executed on symbolic inputs representing multiple concrete inputs. Values of variables are represented as constraints generated from the analysis of Java bytecode. The constraints are solved using off-the shelf solvers to generate test inputs guaranteed to achieve complex coverage criteria. SPF has been used successfully at NASA, in academia, and in industry.

Pathfinder

NASA Image and Video Library

2004-04-15

Pictured in the high bay, is the X-34 Technology Demonstrator in the process of completion. The X-34 wass part of NASA's Pathfinder Program which demonstrated advanced space transportation technologies through the use of flight experiments and experimental vehicles. These technology demonstrators and flight experiments supported the Agency's goal of dramatically reducing the cost of access to space and defined the future of space transportation pushing technology into a new era of space development and exploration at the dawn of the new century. The X-34 program was cancelled in 2001.

Rover Soil Experiments Near Yogi

NASA Technical Reports Server (NTRS)

1997-01-01

Sojourner, while on its way to the rock Yogi, performed several soil mechanics experiments. Piles of loose material churned up from the experiment are seen in front of and behind the Rover. The rock Pop-Tart is visible near the front right rover wheel. Yogi is at upper right. The image was taken by the Imager for Mars Pathfinder.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Design Overview of the DM Radio Pathfinder Experiment

NASA Technical Reports Server (NTRS)

Silva-Feaver, Maximiliano; Chaudhuri, Saptarshi; Cho, Hsaio-Mei; Dawson, Carl; Graham, Peter; Irwin, Kent; Kuenstner, Stephen; Li, Dale; Mardon, Jeremy; Moseley, Harvey;

NASA Ocean Altimeter Pathfinder Project. Report 1; Data Processing Handbook

NASA Technical Reports Server (NTRS)

Koblinsky, C. J.; Beckley, Brian D.; Ray, Richard D.; Wang, Yan-Ming; Tsaoussi, Lucia; Brenner, Anita; Williamson, Ron

1998-01-01

The NOAA/NASA Pathfinder program was created by the Earth Observing System (EOS) Program Office to determine how satellite-based data sets can be processed and used to study global change. The data sets are designed to be long time-sedes data processed with stable calibration and community consensus algorithms to better assist the research community. The Ocean Altimeter Pathfinder Project involves the reprocessing of all altimeter observations with a consistent set of improved algorithms, based on the results from TOPEX/POSEIDON (T/P), into easy-to-use data sets for the oceanographic community for climate research. This report describes the processing schemes used to produce a consistent data set and two of the products derived f rom these data. Other reports have been produced that: a) describe the validation of these data sets against tide gauge measurements and b) evaluate the statistical properties of the data that are relevant to climate change. The use of satellite altimetry for earth observations was proposed in the early 1960s. The first successful space based radar altimeter experiment was flown on SkyLab in 1974. The first successful satellite radar altimeter was flown aboard the Geos-3 spacecraft between 1975 and 1978. While a useful data set was collected from this mission for geophysical studies, the noise in the radar measured and incomplete global coverage precluded ft from inclusion in the Ocean Altimeter Pathfinder program. This program initiated its analysis with the Seasat mission, which was the first satellite radar altimeter flown for oceanography.

Java PathFinder User Guide

NASA Technical Reports Server (NTRS)

Havelund, Klaus

1999-01-01

The JAVA PATHFINDER, JPF, is a translator from a subset of JAVA 1.0 to PROMELA, the programming language of the SPIN model checker. The purpose of JPF is to establish a framework for verification and debugging of JAVA programming based on model checking. The main goal is to automate program verification such that a programmer can apply it in the daily work without the need for a specialist to manually reformulate a program into a different notation in order to analyze the program. The system is especially suited for analyzing multi-threaded JAVA applications, where normal testing usually falls short. The system can find deadlocks and violations of boolean assertions stated by the programmer in a special assertion language. This document explains how to Use JPF.

Disturbing Pop-Tart

NASA Technical Reports Server (NTRS)

1997-01-01

The Sojourner rover's front right camera imaged Pop-tart, a small rock or indurated soil material which was pushed out of the surrounding drift material by Sojourner's front left wheel during a soil mechanics experiment.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Constraints and Approach for Selecting the Mars Surveyor '01 Landing Site

NASA Technical Reports Server (NTRS)

Golombek, M.; Bridges, N.; Gilmore, M.; Haldemann, A.; Parker, T.; Saunders, R.; Spencer, D.; Smith, J.; Weitz, C.

1999-01-01

There are many similarities between the Mars Surveyor '01 (MS '01) landing site selection process and that of Mars Pathfinder. The selection process includes two parallel activities in which engineers define and refine the capabilities of the spacecraft through design, testing and modeling and scientists define a set of landing site constraints based on the spacecraft design and landing scenario. As for Pathfinder, the safety of the site is without question the single most important factor, for the simple reason that failure to land safely yields no science and exposes the mission and program to considerable risk. The selection process must be thorough and defensible and capable of surviving multiple withering reviews similar to the Pathfinder decision. On Pathfinder, this was accomplished by attempting to understand the surface properties of sites using available remote sensing data sets and models based on them. Science objectives are factored into the selection process only after the safety of the site is validated. Finally, as for Pathfinder, the selection process is being done in an open environment with multiple opportunities for community involvement including open workshops, with education and outreach opportunities.

Constraints, Approach and Present Status for Selecting the Mars Surveyor 2001 Landing Site

NASA Technical Reports Server (NTRS)

Golombek, M.; Anderson, F.; Bridges, N.; Briggs, G.; Gilmore, M.; Gulick, V.; Haldemann, A.; Parker, T.; Saunders, R.; Spencer, D.;

Shark

NASA Technical Reports Server (NTRS)

1997-01-01

This false color composite image from the Pathfinder lander shows the rock 'Shark' at upper right (Shark is about 0.69 m wide, 0.40 m high, and 6.4 m from the lander). The rock looks like a conglomerate in Sojourner rover images, but only the large elements of its surface textures can be seen here. This demonstrates the usefulness of having a robot rover geologist able to examine rocks up close.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

AVHRR-Based Polar Pathfinder Products: Evaluation, Enhancement and Transition to MODIS

NASA Technical Reports Server (NTRS)

Fowler, Charles; Masalanik, James; Stone, Robert; Stroeve, Julienne; Emery, William

2001-01-01

The Advanced Very High Resolution Radiometer (AVHRR)-Based Polar Pathfinder (APP) products include calibrated AVHRR channel data, surface temperatures, albedo, satellite scan and solar geometries, and cloud mask, all composited into twice-per-day images, and daily averaged fields of sea ice motion, for regions poleward of 50 latitude. Our general goals under this grant: (1) Quantify the APP accuracy and sources of error by comparing Pathfinder products with field measurements; (2) Determine the consistency of mean fields and trends in comparison with longer time series of available station data and forecast model output; (3) Investigate the consistency of the products between the different AVHRR instruments over the 1982-present period of the NOAA program; and (4) Compare and annual cycle of the APP products with MODIS to establish a baseline for extending Pathfinder-type products into the new ESE period.

Confirmatory Factor Analysis of the Elementary School Success Profile for Teachers

ERIC Educational Resources Information Center

Webber, Kristina C.; Rizo, Cynthia F.; Bowen, Natasha K.

2012-01-01

Objectives: This study examines the factor structure and scale quality of data collected with the online Elementary School Success Profile (ESSP) for Teachers from a sample of teachers of 1,145 third through fifth graders. Methods: Confirmatory factor analysis (CFA) using Mplus and weighted least squares means and variances adjusted (WLSMV)…

Dust Wind Tails Around Rocks

NASA Technical Reports Server (NTRS)

1997-01-01

This image was taken by the Sojourner rover's left front camera on Sol 32. The Pathfinder lander is at right and is about 9 meters away. Wind tails of dust are clearly seen extending from the left side of many of the small rocks in the foreground. The large rocks on the horizon at left center are the next goal of Sojourner as it continues our exploration of Mars.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and managed the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Model Checking JAVA Programs Using Java Pathfinder

NASA Technical Reports Server (NTRS)

Havelund, Klaus; Pressburger, Thomas

2000-01-01

This paper describes a translator called JAVA PATHFINDER from JAVA to PROMELA, the "programming language" of the SPIN model checker. The purpose is to establish a framework for verification and debugging of JAVA programs based on model checking. This work should be seen in a broader attempt to make formal methods applicable "in the loop" of programming within NASA's areas such as space, aviation, and robotics. Our main goal is to create automated formal methods such that programmers themselves can apply these in their daily work (in the loop) without the need for specialists to manually reformulate a program into a different notation in order to analyze the program. This work is a continuation of an effort to formally verify, using SPIN, a multi-threaded operating system programmed in Lisp for the Deep-Space 1 spacecraft, and of previous work in applying existing model checkers and theorem provers to real applications.

Constraints, Approach, and Status of Mars Surveyor 2001 Landing Site Selection

NASA Technical Reports Server (NTRS)

Golombek, M.; Bridges, N.; Briggs, G.; Gilmore, M.; Haldemann, A.; Parker, T.; Saunders, R.; Spencer, D.; Smith, J.; Soderblom, L.

1999-01-01

There are many similarities between the Mars Surveyor '01 (MS '01) landing site selection process and that of Mars Pathfinder. The selection process includes two parallel activities in which engineers define and refine the capabilities of the spacecraft through design, testing and modeling and scientists define a set of landing site constraints based on the spacecraft design and landing scenario. As for Pathfinder, the safety of the site is without question the single most important factor, for the simple reason that failure to land safely yields no science and exposes the mission and program to considerable risk. The selection process must be thorough and defensible and capable of surviving multiple withering reviews similar to the Pathfinder decision. On Pathfinder, this was accomplished by attempting to understand the surface properties of sites using available remote sensing data sets and models based on them. Science objectives are factored into the selection process only after the safety of the site is validated. Finally, as for Pathfinder, the selection process is being done in an open environment with multiple opportunities for community involvement including open workshops, with education and outreach opportunities. Additional information is contained in the original extended abstract.

Yogi the rock - 3D

NASA Technical Reports Server (NTRS)

1997-01-01

Yogi, a rock taller than rover Sojourner, is the subject of this image, taken in stereo by the deployed Imager for Mars Pathfinder (IMP) on Sol 3. 3D glasses are necessary to identify surface detail. The soil in the foreground has been the location of multiple soil mechanics experiments performed by Sojourner's cleated wheels. Pathfinder scientists were able to control the force inflicted on the soil beneath the rover's wheels, giving them insight into the soil's mechanical properties. The soil mechanics experiments were conducted after this image was taken.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

NASA Ocean Altimeter Pathfinder Project. Report 2; Data Set Validation

NASA Technical Reports Server (NTRS)

Koblinsky, C. J.; Ray, Richard D.; Beckley, Brian D.; Bremmer, Anita; Tsaoussi, Lucia S.; Wang, Yan-Ming

1999-01-01

The NOAA/NASA Pathfinder program was created by the Earth Observing System (EOS) Program Office to determine how existing satellite-based data sets can be processed and used to study global change. The data sets are designed to be long time-series data processed with stable calibration and community consensus algorithms to better assist the research community. The Ocean Altimeter Pathfinder Project involves the reprocessing of all altimeter observations with a consistent set of improved algorithms, based on the results from TOPEX/POSEIDON (T/P), into easy-to-use data sets for the oceanographic community for climate research. Details are currently presented in two technical reports: Report# 1: Data Processing Handbook Report #2: Data Set Validation This report describes the validation of the data sets against a global network of high quality tide gauge measurements and provides an estimate of the error budget. The first report describes the processing schemes used to produce the geodetic consistent data set comprised of SEASAT, GEOSAT, ERS-1, TOPEX/ POSEIDON, and ERS-2 satellite observations.

Sunset over Twin Peaks

NASA Technical Reports Server (NTRS)

1997-01-01

This image was taken by the Imager for Mars Pathfinder (IMP) about one minute after sunset on Mars on Sol 21. The prominent hills dubbed 'Twin Peaks' form a dark silhouette at the horizon, while the setting sun casts a pink glow over the darkening sky. The image was taken as part of a twilight study which indicates how the brightness of the sky fades with time after sunset. Scientists found that the sky stays bright for up to two hours after sunset, indicating that Martian dust extends very high into the atmosphere.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Pre-Dawn Martian Sky

NASA Technical Reports Server (NTRS)

1997-01-01

On Sol 39 there were wispy blue clouds in the pre-dawn sky of Mars, as seen by the Imager for Mars Pathfinder (IMP). The color image was made by taking blue, green, and red images and then combining them into a single color image. The clouds appear to have a bluish side and a greenish side because they moved (in the wind from the northeast) between images. This picture was made an hour and twenty minutes before sunrise -- the sun is not shining directly on the water ice clouds, but they are illuminated by the dawn twilight.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Wind effects on Martian soil

NASA Technical Reports Server (NTRS)

1997-01-01

This false-color combination image highlights details of wind effects on the Martian soil at the Pathfinder landing site. Red and blue filter images have been combined to enhance brightness contrasts among several soil units. Martian winds have distributed these lighter and darker fine materials in complex patterns around the rocks in the scene (blue). For scale, the rock at right center is 16 centimeters (6.3 inches) long. This scene is one of several that will be monitored weekly for changes caused by wind activity.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages and Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

SLS Pathfinder Segments Car Train Departure

NASA Image and Video Library

2016-03-02

An Iowa Northern locomotive, contracted by Goodloe Transportation of Chicago, departs from NASA’s Kennedy Space Center in Florida, with two containers on railcars for transport to the Jay Jay railroad yard. The containers held two pathfinders, or test versions, of solid rocket booster segments for NASA’s Space Launch System rocket that were delivered to the Rotation, Processing and Surge Facility (RPSF). Inside the RPSF, the Ground Systems Development and Operations Program and Jacobs Engineering, on the Test and Operations Support Contract, will conduct a series of lifts, moves and stacking operations using the booster segments, which are inert, to prepare for Exploration Mission-1, deep-space missions and the journey to Mars. The pathfinder booster segments are from Orbital ATK in Utah.

SLS Pathfinder Segments Car Train Departure

NASA Image and Video Library

2016-03-02

An Iowa Northern locomotive, contracted by Goodloe Transportation of Chicago, departs from the Rotation, Processing and Surge Facility (RPSF) at NASA’s Kennedy Space Center in Florida, with two containers on railcars for transport to the NASA Jay Jay railroad yard. The containers held two pathfinders, or test versions, of solid rocket booster segments for NASA’s Space Launch System rocket that were delivered to the RPSF. Inside the RPSF, the Ground Systems Development and Operations Program and Jacobs Engineering, on the Test and Operations Support Contract, will conduct a series of lifts, moves and stacking operations using the booster segments, which are inert, to prepare for Exploration Mission-1, deep-space missions and the journey to Mars. The pathfinder booster segments are from Orbital ATK in Utah.

Building Educational Programs for the Australian Square Kilometre Array Pathfinder

NASA Astrophysics Data System (ADS)

Hollow, R.; Hobbs, G.

2010-08-01

The Australian Square Kilometre Array Pathfinder (ASKAP) will be an array of 36 antennas in Western Australia, each 12-m in diameter, and is due for operation in 2013. With a large instantaneous field-of-view ASKAP will survey the whole sky faster than existing radio telescopes, producing massive data sets. Government funding for ASKAP was contingent on it being available for education purposes, providing an exciting opportunity to develop innovative education projects for schools and citizen science. Building on the PULSE@Parkes program we plan to have a range of activities and resources, providing scope for student investigations. Challenges and educational opportunities are discussed.

Generation of Level 3 SMMR and SSM/I Brightness Temperatures for the Period 1978-1999

NASA Technical Reports Server (NTRS)

Partington, Kim

1999-01-01

The NOAA/NASA Pathfinder Program was initially designed to assure that certain key remote sensing data sets of particular significance to global change research were scientifically validated, consistently processed and made readily available to the research community at minimal cost. Through this Program the National Snow and Ice Data Center (NSIDC), University of Colorado has successfully processed, archived and distributed the Scanning Multichannel Microwave Radiometer (SMMR) and Special Sensor Microwave/Imager (SSM/I) Level 3 (EASE-Grid format) Pathfinder data sets for the period 1978 to 1999. These data are routinely distributed to approximately 150 researchers through various media including CD-ROM, 8 mm tape, ftp and the EOS Information Management System (IMS). At NSIDC these data are currently being applied in the development and validation of algorithms to derive snow water equivalent (NASA NAG5-6636), the mapping of frozen ground and the detection of the onset of melt over ice sheets, sea ice and snow cover. The EASE-Grid format, developed at NSIDC in conjunction with the SMMR-SSM/I Pathfinder project has also been applied to Advanced Very High Resolution Radiometer (AVHRR) and TOVS Pathfinder data, as well as ancillary data such as digital elevation, land cover classification and several in situ data sets. EASE-Grid will also be used for all land products derived from the NASA EOS AMSR-E instrument.

Rock Garden

NASA Technical Reports Server (NTRS)

1997-01-01

This false color composite image of the Rock Garden shows the rocks 'Shark' and 'Half Dome' at upper left and middle, respectively. Between these two large rocks is a smaller rock (about 0.20 m wide, 0.10 m high, and 6.33 m from the Lander) that was observed close-up with the Sojourner rover (see PIA00989).

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Diversity of soils near rover deploy region

NASA Technical Reports Server (NTRS)

1997-01-01

The surface near the rover's egress from the lander contains mainly bright red drift (#1), dark gray rocks such as Cradle (# 3), soil intermediate in color to the rocks and drift (#2), and dark red soil on and around the rock Lamb (#4). Globally, Mars is characterized by similar color variations. The spectra, measured using the full 13-color capability of the Imager for Mars Pathfinder (IMP), provide evidence for the mineralogy of the unweathered rocks and highly weathered red soils.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech).

SLS Pathfinder Segments Car Train Departure

NASA Image and Video Library

2016-03-02

An Iowa Northern locomotive, contracted by Goodloe Transportation of Chicago, travels along the NASA railroad bridge over the Indian River north of Kennedy Space Center, carrying one of two containers on a railcar for transport to the NASA Jay Jay railroad yard. The containers held two pathfinders, or test versions, of solid rocket booster segments for NASA’s Space Launch System rocket that were delivered to the Rotation, Processing and Surge Facility (RPSF). Inside the RPSF, the Ground Systems Development and Operations Program and Jacobs Engineering, on the Test and Operations Support Contract, will conduct a series of lifts, moves and stacking operations using the booster segments, which are inert, to prepare for Exploration Mission-1, deep-space missions and the journey to Mars. The pathfinder booster segments are from Orbital ATK in Utah.

SLS Pathfinder Segments Car Train Departure

NASA Image and Video Library

2016-03-02

An Iowa Northern locomotive, conracted by Goodloe Transportation of Chicago, travels along the NASA railroad bridge over the Indian River north of Kennedy Space Center, with two containers on railcars for transport to the NASA Jay Jay railroad yard. The containers held two pathfinders, or test versions, of solid rocket booster segments for NASA’s Space Launch System rocket that were delivered to the Rotation, Processing and Surge Facility (RPSF). Inside the RPSF, the Ground Systems Development and Operations Program and Jacobs Engineering, on the Test and Operations Support Contract, will conduct a series of lifts, moves and stacking operations using the booster segments, which are inert, to prepare for Exploration Mission-1, deep-space missions and the journey to Mars. The pathfinder booster segments are from Orbital ATK in Utah.

SLS Pathfinder Segments Car Train Departure

NASA Image and Video Library

2016-03-02

An Iowa Northern locomotive, contracted by Goodloe Transportation of Chicago, approaches the raised span of the NASA railroad bridge to continue over the Indian River north of Kennedy Space Center with two containers on railcars for storage at the NASA Jay Jay railroad yard. The containers held two pathfinders, or test versions, of solid rocket booster segments for NASA’s Space Launch System rocket that were delivered to the Rotation, Processing and Surge Facility (RPSF). Inside the RPSF, the Ground Systems Development and Operations Program and Jacobs Engineering, on the Test and Operations Support Contract, will conduct a series of lifts, moves and stacking operations using the booster segments, which are inert, to prepare for Exploration Mission-1, deep-space missions and the journey to Mars. The pathfinder booster segments are from Orbital ATK in Utah.

SLS Pathfinder Segments Car Train Departure

NASA Image and Video Library

2016-03-02

An Iowa Northern locomotive, contracted by Goodloe Transportation of Chicago, travels along the NASA railroad bridge over the Indian River north of Kennedy Space Center, carrying one of two containers on a railcar for transport to the NASA Jay Jay railroad yard near the center. The containers held two pathfinders, or test versions, of solid rocket booster segments for NASA’s Space Launch System rocket that were delivered to the Rotation, Processing and Surge Facility (RPSF). Inside the RPSF, the Ground Systems Development and Operations Program and Jacobs Engineering, on the Test and Operations Support Contract, will conduct a series of lifts, moves and stacking operations using the booster segments, which are inert, to prepare for Exploration Mission-1, deep-space missions and the journey to Mars. The pathfinder booster segments are from Orbital ATK in Utah.

SLS Pathfinder Segments Car Train Departure

NASA Image and Video Library

2016-03-02

An Iowa Northern locomotive, contracted by Goodloe Transportation of Chicago, continues along the NASA railroad bridge over the Indian River north of Kennedy Space Center, carrying one of two containers on a railcar for transport to the NASA Jay Jay railroad yard. The containers held two pathfinders, or test versions, of solid rocket booster segments for NASA’s Space Launch System rocket that were delivered to the Rotation, Processing and Surge Facility (RPSF). Inside the RPSF, the Ground Systems Development and Operations Program and Jacobs Engineering, on the Test and Operations Support Contract, will conduct a series of lifts, moves and stacking operations using the booster segments, which are inert, to prepare for Exploration Mission-1, deep-space missions and the journey to Mars. The pathfinder booster segments are from Orbital ATK in Utah.

Pathfinder in flight over Hawaii

NASA Image and Video Library

1997-08-28

Pathfinder, NASA's solar-powered, remotely-piloted aircraft is shown while it was conducting a series of science flights to highlight the aircraft's science capabilities while collecting imagery of forest and coastal zone ecosystems on Kauai, Hawaii. The flights also tested two new scientific instruments, a high spectral resolution Digital Array Scanned Interferometer (DASI) and a high spatial resolution Airborne Real-Time Imaging System (ARTIS). The remote sensor payloads were designed by NASA's Ames Research Center, Moffett Field, California, to support NASA's Mission to Planet Earth science programs.

Pathfinder over runway in Hawaii

NASA Image and Video Library

1997-08-28

Pathfinder, NASA's solar-powered, remotely-piloted aircraft is shown while it was conducting a series of science flights to highlight the aircraft's science capabilities while collecting imagery of forest and coastal zone ecosystems on Kauai, Hawaii. The flights also tested two new scientific instruments, a high-spectral-resolution Digital Array Scanned Interferometer (DASI) and a high-spatial-resolution Airborne Real-Time Imaging System (ARTIS). The remote sensor payloads were designed by NASA's Ames Research Center, Moffett Field, California, to support NASA's Mission to Planet Earth science programs.

Grid resolution and solution convergence for Mars Pathfinder forebody

NASA Technical Reports Server (NTRS)

Nettelhorst, Heather L.; Mitcheltree, Robert A.

1994-01-01

As part of the Discovery Program, NASA Plans to launch a series of probes to Mars. The Mars Pathfinder project is the first of this series with a scheduled Mars arrival in July 1997. The entry vehicle will perform a direct entry into the atmosphere and deliver a lander to the surface. Predicting the entry vehicle's flight performance and designing the forebody heatshield requires knowledge of the expected aerothermodynamic environment. Much of this knowledge can be obtained through computational fluid dynamic (CFD) analysis.

Hillary Clinton visits Pathfinder projects in Brazil.

PubMed

1996-01-01

In October 1995, US First Lady Hillary Clinton visited a maternity hospital in Salvador, Brazil, in which a family planning (FP)/reproductive health program has been administered by Pathfinder International since 1981 with funding from USAID. During her tour of the facility, Clinton learned about the high degree of unmet need for FP in the region which results from a lack of sufficient resources to meet demand. Clinton, in turn, praised the state of Bahia for its emphasis on FP in low-income areas.

Mars pathfinder Rover egress deployable ramp assembly

NASA Technical Reports Server (NTRS)

Spence, Brian R.; Sword, Lee F.

1996-01-01

The Mars Pathfinder Program is a NASA Discovery Mission, led by the Jet Propulsion Laboratory, to launch and place a small planetary Rover for exploration on the Martian surface. To enable safe and successful egress of the Rover vehicle from the spacecraft, a pair of flight-qualified, deployable ramp assemblies have been developed. This paper focuses on the unique, lightweight deployable ramp assemblies. A brief mission overview and key design requirements are discussed. Design and development activities leading to qualification and flight systems are presented.

Verification Tools Secure Online Shopping, Banking

NASA Technical Reports Server (NTRS)

2010-01-01

Just like rover or rocket technology sent into space, the software that controls these technologies must be extensively tested to ensure reliability and effectiveness. Ames Research Center invented the open-source Java Pathfinder (JPF) toolset for the deep testing of Java-based programs. Fujitsu Labs of America Inc., based in Sunnyvale, California, improved the capabilities of the JPF Symbolic Pathfinder tool, establishing the tool as a means of thoroughly testing the functionality and security of Web-based Java applications such as those used for Internet shopping and banking.

Java PathFinder: A Translator From Java to Promela

NASA Technical Reports Server (NTRS)

Havelund, Klaus

1999-01-01

JAVA PATHFINDER, JPF, is a prototype translator from JAVA to PROMELA, the modeling language of the SPIN model checker. JPF is a product of a major effort by the Automated Software Engineering group at NASA Ames to make model checking technology part of the software process. Experience has shown that severe bugs can be found in final code using this technique, and that automated translation from a programming language to a modeling language like PROMELA can help reducing the effort required.

jFuzz: A Concolic Whitebox Fuzzer for Java

NASA Technical Reports Server (NTRS)

Jayaraman, Karthick; Harvison, David; Ganesh, Vijay; Kiezun, Adam

2009-01-01

We present jFuzz, a automatic testing tool for Java programs. jFuzz is a concolic whitebox fuzzer, built on the NASA Java PathFinder, an explicit-state Java model checker, and a framework for developing reliability and analysis tools for Java. Starting from a seed input, jFuzz automatically and systematically generates inputs that exercise new program paths. jFuzz uses a combination of concrete and symbolic execution, and constraint solving. Time spent on solving constraints can be significant. We implemented several well-known optimizations and name-independent caching, which aggressively normalizes the constraints to reduce the number of calls to the constraint solver. We present preliminary results due to the optimizations, and demonstrate the effectiveness of jFuzz in creating good test inputs. The source code of jFuzz is available as part of the NASA Java PathFinder. jFuzz is intended to be a research testbed for investigating new testing and analysis techniques based on concrete and symbolic execution. The source code of jFuzz is available as part of the NASA Java PathFinder.

History of the numerical aerodynamic simulation program

NASA Technical Reports Server (NTRS)

Peterson, Victor L.; Ballhaus, William F., Jr.

1987-01-01

The Numerical Aerodynamic Simulation (NAS) program has reached a milestone with the completion of the initial operating configuration of the NAS Processing System Network. This achievement is the first major milestone in the continuing effort to provide a state-of-the-art supercomputer facility for the national aerospace community and to serve as a pathfinder for the development and use of future supercomputer systems. The underlying factors that motivated the initiation of the program are first identified and then discussed. These include the emergence and evolution of computational aerodynamics as a powerful new capability in aerodynamics research and development, the computer power required for advances in the discipline, the complementary nature of computation and wind tunnel testing, and the need for the government to play a pathfinding role in the development and use of large-scale scientific computing systems. Finally, the history of the NAS program is traced from its inception in 1975 to the present time.

Wind Drifts at Viking 1 Landing Site

NASA Technical Reports Server (NTRS)

1997-01-01

This image is of so-called wind drifts seen at the Viking 1 landing site. These are somewhat different from the features seen at the Pathfinder site in two important ways. 1) These landforms have no apparent slip-or avalanche-face as do both terrestrial dunes and the Pathfinder features, and may represent deposits of sediment falling from the air, as opposed to dune sand, which 'hops' or saltates along the ground; 2) these features may indicate erosion on one side, because of the layering and apparent scouring on their right sides. They may, therefore have been deposited by a wind moving left to right, partly or weakly cemented or solidified by surface processes at some later time, then eroded by a second wind (right to left), exposing their internal structure.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Sojourner near the Rock Garden

NASA Technical Reports Server (NTRS)

1997-01-01

This image of the Sojourner rover was taken near the end of daytime operations on Sol 42. The rover is between the rocks 'Wedge' (left) and 'Flute Top' (right). Other rocks visible include 'Flat Top' (behind Flute Top) and those in the Rock Garden, at the top of the frame. The cylindrical object extending from the back end of Sojourner is the Alpha Proton X-Ray Spectrometer.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Earth Futures: a General Education Sustainability Course at the Pennsylvania State University

NASA Astrophysics Data System (ADS)

Bralower, T. J.; Bice, D. M.; Barron, E. J.

2012-12-01

Earth in the Future: Predicting Climate Change and Its Impacts Over the Next Century has been taught at The Pennsylvania State University since 2000. The course is a general education course designed to give a broad survey of the science underlying climate change as well as the impacts on natural and human systems. The course has three major goals: (1) to provide an understanding of climate science and of the possible scenarios of how climate may change in the future; (2) to analyze the linkages between climate and major human and natural systems, including agriculture, water, ocean circulation, and coastal ecosystems, necessary to assess the potential impacts of climate change; and (3) to understand the potential responses to climate change, including both adaptation to, and mitigation of change. The general education course is the entry point for a new BS-degree program, Earth System Science and Policy (ESSP). Initially the course was taught face to face on a yearly basis. Recently we have developed an on-line version of the course, and, in Fall semester, 2012, we are teaching a revised version of the course face-to-face and on-line. Both versions of the course are being assessed using survey instruments developed for InTeGrate courses. The simultaneous instruction provides a unique opportunity to compare the strengths and weaknesses of the two different modes of education. From its beginning, the course has included laboratory exercises designed to enhance the student's understanding of climate science. The revised course includes laboratory exercises in every module, including STELLA-based model experiments. These exercises form an essential part of the on-line version of the course, however, the identical exercises are involved in the face-to-face version. In our presentation, we provide preliminary comparison of the two instructional modes as well as their effectiveness in recruiting students to the ESSP major.

Pathfinders: A Self-Care and Health Education Program for Older Widows and Widowers.

ERIC Educational Resources Information Center

Caserta, Michael S.; Lund, Dale A.; Rice, Sarah Jane

1999-01-01

Describes a research-based self-care health education program for recently widowed people. Program aims to provide a foundation of knowledge, motivation, and encouragement to initiate positive behavioral changes, and to establish a support network. Preliminary analysis suggests the program is achieving many of the intended outcomes. (Author/JDM)

X-37 CD Rom (Mini Business Card Version)

NASA Technical Reports Server (NTRS)

Stewart, Scotty

2000-01-01

The mini X-37 CD was developed as an educational tool for the public and commercial industry about the X-37 pathfinder vehicle program. This CD contains overview information about the X-37 program along with general vehicle system and technology description information.

Pooh Bear rock and Mermaid Dune

NASA Technical Reports Server (NTRS)

1997-01-01

One of the two forward cameras aboard Sojourner imaged this area of Martian terrain on Sol 26. The large rock dubbed 'Pooh Bear' is at far left, and stands between four and five inches high. Mermaid Dune is the smooth area stretching horizontally across the top quarter of the image. The Alpha Proton X-Ray Spectrometer (APXS) instrument aboard Sojourner will be deployed on Mermaid Dune, and the rover will later use its cleated wheels to dig into it.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages and Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Space Launch System Base Heating Test: Sub-Scale Rocket Engine/Motor Design, Development & Performance Analysis

NASA Technical Reports Server (NTRS)

Mehta, Manish; Seaford, Mark; Kovarik, Brian; Dufrene, Aaron; Solly, Nathan

2014-01-01

ATA-002 Technical Team has successfully designed, developed, tested and assessed the SLS Pathfinder propulsion systems for the Main Base Heating Test Program. Major Outcomes of the Pathfinder Test Program: Reach 90% of full-scale chamber pressure Achieved all engine/motor design parameter requirements Reach steady plume flow behavior in less than 35 msec Steady chamber pressure for 60 to 100 msec during engine/motor operation Similar model engine/motor performance to full-scale SLS system Mitigated nozzle throat and combustor thermal erosion Test data shows good agreement with numerical prediction codes Next phase of the ATA-002 Test Program Design & development of the SLS OML for the Main Base Heating Test Tweak BSRM design to optimize performance Tweak CS-REM design to increase robustness MSFC Aerosciences and CUBRC have the capability to develop sub-scale propulsion systems to meet desired performance requirements for short-duration testing.

Space Launch System Base Heating Test: Sub-Scale Rocket Engine/Motor Design, Development and Performance Analysis

NASA Technical Reports Server (NTRS)

Mehta, Manish; Seaford, Mark; Kovarik, Brian; Dufrene, Aaron; Solly, Nathan; Kirchner, Robert; Engel, Carl D.

2014-01-01

The Space Launch System (SLS) base heating test is broken down into two test programs: (1) Pathfinder and (2) Main Test. The Pathfinder Test Program focuses on the design, development, hot-fire test and performance analyses of the 2% sub-scale SLS core-stage and booster element propulsion systems. The core-stage propulsion system is composed of four gaseous oxygen/hydrogen RS-25D model engines and the booster element is composed of two aluminum-based model solid rocket motors (SRMs). The first section of the paper discusses the motivation and test facility specifications for the test program. The second section briefly investigates the internal flow path of the design. The third section briefly shows the performance of the model RS-25D engines and SRMs for the conducted short duration hot-fire tests. Good agreement is observed based on design prediction analysis and test data. This program is a challenging research and development effort that has not been attempted in 40+ years for a NASA vehicle.

Shark as viewed by Sojourner Rover

NASA Technical Reports Server (NTRS)

1998-01-01

This close-up image of Shark, in the Bookshelf at the back of the Rock Garden, was taken by Sojourner Rover on Sol 75. Also in the image are Half Dome (right) and Desert Princess (lower right). At the bottom left, a thin 'crusty' soil layer has been disturbed by the rover wheels.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Rock Garden Mosaic

NASA Technical Reports Server (NTRS)

1997-01-01

This image mosaic of part of the 'Rock Garden' was taken by the Sojourner rover's left front camera on Sol 71 (September 14). The rock 'Shark' is at left center and 'Half Dome' is at right. Fine-scale textures on the rocks are clearly seen. Broken crust-like material is visible at bottom center.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

North Twin Peak in super resolution

NASA Technical Reports Server (NTRS)

1997-01-01

This pair of images shows the result of taking a sequence of 25 identical exposures from the Imager for Mars Pathfinder (IMP) of the northern Twin Peak, with small camera motions, and processing them with the Super-Resolution algorithm developed at NASA's Ames Research Center.

The upper image is a representative input image, scaled up by a factor of five, with the pixel edges smoothed out for a fair comparison. The lower image allows significantly finer detail to be resolved.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

The super-resolution research was conducted by Peter Cheeseman, Bob Kanefsky, Robin Hanson, and John Stutz of NASA's Ames Research Center, Mountain View, CA. More information on this technology is available on the Ames Super Resolution home page at

http://ic-www.arc.nasa.gov/ic/projects/bayes-group/ group/super-res/

An Analysis of Coupling between the x1 and x12 Interferometers for LISA Pathfinder

NASA Astrophysics Data System (ADS)

Howard, Brittany

2017-01-01

Due to tolerances in the manufacturing process, noise from the jittering of the spacecraft housing LISA Pathfinder (LPF) is appearing in the differential measurement between its two test masses (TM's). This phenomenon manifests as a small but measurable coupling between the readouts of LPF's two heterodyne interferometers, x1 and x12. In this study, two LISA Pathfinder experiments are analyzed using three methods in an effort to characterize and quantify the coupling as well as to potentially identify its source. The main question considered is this: does the coupling change with the absolute displacement between the TM's? As a result of this work, reliable values for coupling between LPF's x1 and x12 interferometers are found, and they are seen to depend on the absolute displacement between the test masses to some degree. Completed at the Albert Einstein Institute for Gravitational Physics under the International REU program from the University of Florida.

Pebbles, Cobbles, and Sockets

NASA Technical Reports Server (NTRS)

1997-01-01

This Rover image of 'Shark' (upper left center), 'Half Dome' (upper right), and a small rock (right foreground) reveal textures and structures not visible in lander camera images. These rocks are interpreted as conglomerates because their surfaces have rounded protrusions up to several centimeters in size. It is suggested that the protrusions are pebbles and granules.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Sojourner Rover View of Sockets and Pebbles

NASA Technical Reports Server (NTRS)

1997-01-01

Well-rounded objects, like the ones in this image, were not seen at the Viking sites. These are thought to be pebbles liberated from sedimentary rocks composed of cemented silts, sands and rounded fragments; such rocks are called conglomerates. The 'sockets' could be the former sites of such pebbles.

NOTE: original caption as published in Science Magazine

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Wind Tails Near Chimp

NASA Technical Reports Server (NTRS)

1997-01-01

This image of the rock 'Chimp' was taken by the Sojourner rover's right front camera on Sol 72 (September 15). Fine-scale texture on Chimp and other rocks is clearly visible. Wind tails, oriented from lower right to upper left, are seen next to small pebbles in the foreground. These were most likely produced by wind action.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Stereo Images of Wind Tails Near Chimp

NASA Technical Reports Server (NTRS)

1997-01-01

This stereo image pair of the rock 'Chimp' was taken by the Sojourner rover's front cameras on Sol 72 (September 15). Fine-scale texture on Chimp and other rocks is clearly visible. Wind tails, oriented from lower right to upper left, are seen next to small pebbles in the foreground. These were most likely produced by wind action.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Mars Underground News.

NASA Astrophysics Data System (ADS)

Edgett, K.

Contents: Next entry to Mars (Mars Pathfinder and the microrover Sojourner). Hello, Mars, we're back! Mars Global Surveyor update. The Mars program - 2001 and beyond. Schedule of missions to Mars (as of June 11, 1997). Mars on the Web.

A New Coherent Science Content Storyline Astronomy Course for Pre-Service Teachers at Penn State

NASA Astrophysics Data System (ADS)

Palma, Christopher; Plummer, Julia; Earth and Space Science Partnership

2016-01-01

The Earth and Space Science Partnership (ESSP) is a collaboration among Penn State scientists, science educators and seven school districts across Pennsylvania. One of the ESSP goals has been to provide pre-service teachers with new or improved science course offerings at Penn State in the Earth and Space Science domains. In particular, we aim to provide students with opportunities to learn astronomy content knowledge through teaching methods that engage them in investigations where they experience the practices used by astronomers. We have designed a new course that builds on our research into students' ideas about Solar System astronomy (Plummer et al. 2015) and the curriculum our team created for a professional development workshop for in-service teachers (Palma et al. 2013) with this same theme. The course was offered for the first time in the spring 2015 semester. We designed the course using a coherent science content storyline approach (see, e.g., Palma et al. 2014), which requires all of the student investigations to build towards a big idea in science; in this case, we chose the model for formation of our Solar System. The course led pre-service teachers through a series of investigations that model the type of instruction we hope they will adopt in their own classrooms. They were presented with a series of research questions that all tie in to the big idea of Solar System formation, and they were responsible for collecting and interpreting their own data to draw evidence-based conclusions about one aspect of this model. Students in the course were assessed on their astronomy content knowledge, but also on their ability to construct arguments using scientific reasoning to answer astronomy questions. In this poster, we will present descriptions of the investigations, the assessments used, and our preliminary results about how the course led this group of pre-service teachers to improved understanding of astronomy content and the practices astronomers use in their investigations of the Solar System.We gratefully acknowledge support from the NSF MSP program award DUE#0962792.

Mars Pathfinder Landing Site Workshop 2: Characteristics of the Ares Vallis Region and Field Trips in the Channeled Scabland, Washington

NASA Technical Reports Server (NTRS)

Golombek, M. P. (Editor); Edgett, K. S. (Editor); Rice, J. W., Jr. (Editor)

1995-01-01

This volume, the first of two comprising the technical report for this workshop, contains papers that have been accepted for presentation at the Mars Pathfinder Landing Site Workshop 2: Characteristics of the Ares Vallis Region, September 24-30, 1995, in Spokane, Washington. The Mars Pathfinder Project received a new start in October 1993 as one of the next missions in NASA's long-term Mars exploration program. The mission involves landing a single vehicle on the surface of Mars in 1997. The project is one of the first Discovery-class missions and is required to be a quick, low-cost mission and achieve a set of significant but focused engineering, science, and technology objectives. The primary objective is to demonstrate a low-cost cruise, entry, descent, and landing system required to place a payload on the martian surface in a safe, operational configuration. Additional objectives include the deployment and operation of various science instruments and a microrover. Pathfinder paves the way for a cost-effective implementation of future Mars lander missions. Also included in this volume is the field trip guide to the Channeled Scabland and Missoula Lake Break-out. On July 4, 1997, Mars Pathfinder is scheduled to land near 19.5 deg N, 32.8 deg W, in a portion of Ares Vallis. The landing ellipse covers a huge (100 x 200 km) area that appears to include both depositional and erosional landforms created by one or more giant, catastrophic floods. One of the best known terrestrial analogs to martian outflow channels (such as Ares Vallis) is the region known as the Channeled Scabland. The field trip guide describes some of the geomorphological features of the Channeled Scabland and adjacent Lake Missoula break-out area near Lake Pend Oreille, Idaho.

Overhead View of Area Surrounding Pathfinder

NASA Technical Reports Server (NTRS)

1997-01-01

Overhead view of the area surrounding the Pathfinder lander illustrating the Sojourner traverse. Red rectangles are rover positions at the end of sols 1-30. Locations of soil mechanics experiments, wheel abrasion experiments, and APXS measurements are shown. The A numbers refer to APXS measurements as discussed in the paper by Rieder et al. (p. 1770, Science Magazine, see image note). Coordinates are given in the LL frame.

The photorealistic, interactive, three-dimensional virtual reality (VR) terrain models were created from IMP images using a software package developed for Pathfinder by C. Stoker et al. as a participating science project. By matching features in the left and right camera, an automated machine vision algorithm produced dense range maps of the nearfield, which were projected into a three-dimensional model as a connected polygonal mesh. Distance and angle measurements can be made on features viewed in the model using a mouse-driven three-dimensional cursor and a point-and-click interface. The VR model also incorporates graphical representations of the lander and rover and the sequence and spatial locations at which rover data were taken. As the rover moved, graphical models of the rover were added for each position that could be uniquely determined using stereo images of the rover taken by the IMP. Images taken by the rover were projected into the model as two-dimensional 'billboards' to show the proper perspective of these images.

NOTE: original caption as published in Science Magazine

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

First image of clouds over Mars

NASA Technical Reports Server (NTRS)

1997-01-01

This is the first image ever taken from the surface of Mars of an overcast sky. Featured are stratus clouds coming from the northeast at about 15 miles per hour (6.7 meters/second) at an approximate height of ten miles (16 kilometers) above the surface. The 'you are here' notation marks where Earth was situated in the sky at the time the image was taken. Scientists had hoped to see Earth in this image, but the cloudy conditions prevented a clear viewing. Similar images will be taken in the future with the hope of capturing a view of Earth. From Mars, Earth would appear as a tiny blue dot as a star would appear to an Earthbound observer. Pathfinder's imaging system will not be able to resolve Earth's moon. The clouds consist of water ice condensed on reddish dust particles suspended in the atmosphere. Clouds on Mars are sometimes localized and can sometimes cover entire regions, but have not yet been observed to cover the entire planet. The image was taken about an hour and forty minutes before sunrise by the Imager for Mars Pathfinder (IMP) on Sol 16 at about ten degrees up from the eastern Martian horizon.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages and Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Exobiology opportunities from Discovery-class missions. [Abstract only

NASA Technical Reports Server (NTRS)

Meyer, Michael A.; Rummel, John D.

1994-01-01

Discovery-class missions that are now planned, and those in the concept stage, have the potential to expand our knowledge of the origins and evolution of biogenic compounds, and ultimately, of the origins of life in the solar system. This class of missions, recently developed within NASA's Solar System Exploration Program, is designed to meet important scientific objectives within stringent guidelines--$150 million cap on development cost and a 3-year cap on the development schedule. The Discovery Program will effectively enable "faster, cheaper" missions to explore the inner solar system. The first two missions are Mars Environmental Survey (MESUR) Pathfinder and Near Earth Asteroid Rendezvous (NEAR). MESUR Pathfinder will be the first Discovery mission, with launch planned for November/December 1996. It will be primarily a technical demonstration and validation of the MESUR Program--a network of automated landers to study the internal structure, meteorology, and surface properties of Mars. Besides providing engineering data, Pathfinder will carry atmospheric instrumentation and imaging capabilities, and may deploy a microrover equipped with an alpha proton X-ray spectrometer to determine elemental composition, particularly the lighter elements of exobiological interest. NEAR is expected to be launched in 1998 and to rendezvous with a near-Earth asteroid for up to 1 year. During this time, the spacecraft will assess the asteroid's mass, size, density, map its surface topography and composition, determine its internal properties, and study its interaction with the interplanetary environment. A gamma ray or X-ray spectrometer will be used to determine elemental composition. An imaging spectrograph, with 0.35 to 2.5 micron spectral range, will be used to determine the asteroid's compositional disbribution. Of the 11 Discovery mission concepts that have been designated as warranting further study, several are promising in terms of determining the composition and chemical evolution of organic matter on small planetary bodies. The following mission concepts are of particular interest to the Exobiology Program: Cometary coma chemical composition, comet nucleus tour, near earth asteroid returned sample, small missions to asteroids and comets, and solar wind sample return. The following three Discovery mission concepts that have been targeted for further consideration are relevant to the study of the evolution of biogenic compounds: Comet nucleus penetrator, mainbelt asteroid rendezvous explorer, and the Mars polar Pathfinder.

Sockets and Pebbles

NASA Technical Reports Server (NTRS)

1997-01-01

This close-up Sojourner rover image of a small rock shows that weathering has etched-out pebbles to produce sockets. In the image, sunlight is coming from the upper left. Sockets (with shadows on top) are visible at the lower left and pebbles (with bright tops and shadowed bases) are seen at the lower center and lower right. Two pebbles (about 0.5 cm across) are visible at the lower center.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

SRB Processing Facilities Media Event

NASA Image and Video Library

2016-03-01

Members of the news media watch as two cranes are used to lift one of two pathfinders, or test versions, of solid rocket booster segments for NASA’s Space Launch System (SLS) rocket into the vertical position inside the Rotation, Processing and Surge Facility at NASA’s Kennedy Space Center in Florida. The pathfinder booster segment will be moved to the other end of the RPSF and secured on a test stand. The Ground Systems Development and Operations Program and Jacobs Engineering, on the Test and Operations Support Contract, will prepare the booster segments, which are inert, for a series of lifts, moves and stacking operations to prepare for Exploration Mission-1, deep-space missions and the journey to Mars.

The Australian SKA Pathfinder: operations management and user engagement

NASA Astrophysics Data System (ADS)

Harvey-Smith, Lisa

2016-07-01

This paper describes the science operations model for the Australian Square Kilometre Array Pathfinder (ASKAP) telescope. ASKAP is a radio interferometer currently being commissioned in Western Australia. It will be operated by a dedicated team of observatory staff with the support of telescope monitoring, control and scheduling software. These tools, as well as the proposal tools and data archive will enable the telescope to operate with little direct input from the astronomy user. The paper also discusses how close engagement with the telescope user community has been maintained throughout the ASKAP construction and commissioning phase, leading to positive outcomes including early input into the design of telescope systems and a vibrant early science program.

Sojourner Rover View of Shark and Half Dome

NASA Technical Reports Server (NTRS)

1997-01-01

The rounded knobs (arrows) up to 3 or 4 cm wide on Shark (left; approximately 70 cm wide)) and Half Dome (upper right) and in the foreground could be pebbles in a cemented matrix of clays, silts, and sands; such rocks are called conglomerates. Well-rounded objects like these were not seen at the Viking sites.

NOTE: original caption as published in Science Magazine.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Sojourner Rover Tracks in Compressible Soil

NASA Technical Reports Server (NTRS)

1997-01-01

Sojourner's observations in the Ares region on Mars raise and answer questions about the origins of the rocks and other deposits found there. Deposits are not the same everywhere. In compressible soil, a rover wheel produced ruts with steep walls, marginal slumps, and nearly perfect reflective casts of the spacing between the cleats.

NOTE: original caption as published in Science Magazine

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Dynamic Pathfinders: Leveraging Your OPAC to Create Resource Guides

ERIC Educational Resources Information Center

Hunter, Ben

2008-01-01

Library pathfinders are a time-tested method of leading library users to important resources. However, paper-based pathfinders suffer from space limitations, and both paper-based and Web-based pathfinders require frequent updates to keep up with new library acquisitions. This article details a step-by-step method to create an online dynamic…

Pathfinder aircraft taking off - setting new solar powered altitude record

NASA Technical Reports Server (NTRS)

1995-01-01

The Pathfinder solar-powered remotely piloted aircraft climbs to a record-setting altitude of 50,567 feet during a flight Sept. 11, 1995, at NASA's Dryden Flight Research Center, Edwards, California. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

Mars Pathfinder Landing Site Workshop 2: Characteristics of the Ares Vallis Region and Field Trips in the Channeled Scabland, Washington

NASA Technical Reports Server (NTRS)

Golombek, M. P. (Editor); Edgett, K. S. (Editor); Rice, J. W. , Jr. (Editor)

1995-01-01

Mars Pathfinder will place a single lander on the surface of Mars on July 4, 1997, following a December 1996 launch. As a result of the very successful first Mars Pathfinder Landing Site Workshop, the project has selected the Ares Vallis outflow channel in Chryse Planitia as the landing site. This location is where a large catastrophic outflow channel debouches into the northern lowlands. A second workshop and series of field trips, entitled Mars Pathfinder Landing Site Workshop 2: Characteristics of the Ares Vallis Region and Field Trips in the Channeled Scabland, Washington, were held in Spokane and Moses Lake, Washington. The purpose of the workshop was to provide a focus for learning as much as possible about the Ares Vallis region on Mars before landing there. The rationale is that the more that can be learned about the general area prior to landing, the better scientists will be able interpret the observations made by the lander and rover and place them in the proper geologic context. The field trip included overflights and surface investigations of the Channeled Scabland (an Earth analog for the martian catastrophic outflow channels), focusing on areas particularly analogous to Ares Vallis and the landing site. The overflights were essential for placing the enormous erosional and depositional features of the Channeled Scabland into proper three-dimensional context. The field trips were a joint educational outreach activity involving K-12 science educators, Mars Pathfinder scientists and engineers, and interested scientists from the Mars scientific community. Part 1 of the technical report on this workshop includes a description of the Mars Pathfinder mission, abstracts accepted for presentation at the workshop, an introduction to the Channeled Scabland, and field trip guides for the overflight and two field trips. This part, Part 2, includes the program for the workshop, summaries of the workshop technical sessions, a summary of the field trips and ensuing discussions, late abstracts of workshop presentations, reports on the education and public outreach activities carried out by the educators, and a list of the workshop and field trip participants.

MARS PATHFINDER CAMERA TEST IN SAEF-2

NASA Technical Reports Server (NTRS)

1996-01-01

In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), workers from the Jet Propulsion Laboratory (JPL) are conducting a systems test of the imager for the Mars Pathfinder. Mounted on the Pathfinder lander, the imager (the white cylindrical element the worker is touching) is a specially designed camera featuring a stereo-imaging system with color capability provided by a set of selectable filters. It is mounted on an extendable mast that will pop up after the lander touches down on the Martian surface. The imager will transmit images of the terrain, allowing engineers back on Earth to survey the landing site before the Pathfinder rover is deployed to explore the area. The Mars Pathfinder is scheduled for launch aboard a Delta II expendable launch vehicle on Dec. 2. JPL manages the Pathfinder project for NASA.

Mars Pathfinder Status at Launch

NASA Technical Reports Server (NTRS)

Spear, A. J.; Freeman, Delma C., Jr.; Braun, Robert D.

1996-01-01

The Mars Pathfinder Flight System is in final test, assembly and launch preparations at the Kennedy Space Center in Florida. Launch is scheduled for 2 Dec. 1996. The Flight System development, in particular the Entry, Descent, and Landing (EDL) system, was a major team effort involving JPL, other NASA centers and industry. This paper provides a summary Mars Pathfinder description and status at launch. In addition, a section by NASA's Langley Research Center, a key EDL contributor, is provided on their support to Mars Pathfinder. This section is included as an example of the work performed by Pathfinder team members outside JPL.

Sojourner Rover View of Cloddy Deposits near Pooh Bear

NASA Technical Reports Server (NTRS)

1997-01-01

Sojourner's observations in the Ares region on Mars raise and answer questions about the origins of the rocks and other deposits found there. Deposits are not the same everywhere. Bright, fine-grained drifts (right center) are abundant as thin (less than a few centimeters), discontinuous ridged sheets and wind tails that overlie cloddy deposits of dust, clods, and tiny (less than 1 cm) rocks.

NOTE: original caption as published in Science Magazine

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Mosaic of Wedge, Shark, Half-Dome, Moe and Flat Top

NASA Technical Reports Server (NTRS)

1997-01-01

The front cameras aboard the rover Sojourner imaged several prominent rocks on Sol 44. The highly-textured rock at left is Wedge, and in the background from left to right are Shark, Half-Dome, and Moe. The rectangular rock at right is Flat Top, which earlier close-up images revealed to be made up of elongated pits, possibly made by vesicles from volcanic outgassing or etches caused by weathering.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Pathfinder aircraft liftoff on altitude record setting flight of 71,500 feet

NASA Technical Reports Server (NTRS)

1997-01-01

The Pathfinder aircraft has set a new unofficial world record for high-altitude flight of over 71,500 feet for solar-powered aircraft at the U.S. Navy's Pacific Missile Range Facility, Kauai, Hawaii. Pathfinder was designed and manufactured by AeroVironment, Inc, of Simi Valley, California, and was operated by the firm under a jointly sponsored research agreement with NASA's Dryden Flight Research Center, Edwards, California. Pathfinder's record-breaking flight occurred July 7, 1997. The aircraft took off at 11:34 a.m. PDT, passed its previous record altitude of 67,350 feet at about 5:45 p.m. and then reached its new record altitude at 7 p.m. The mission ended with a perfect nighttime landing at 2:05 a.m. PDT July 8. The new record is the highest altitude ever attained by a propellor-driven aircraft. Before Pathfinder, the altitude record for propellor-driven aircraft was 67,028 feet, set by the experimental Boeing Condor remotely piloted aircraft. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

LISA Pathfinder

NASA Technical Reports Server (NTRS)

Stebbins, Robin

2008-01-01

USA Pathfinder is a space mission dedicated to demonstrating technology for the Laser Interferometer Space Antenna (LISA). LISA is a joint ESA/NASA mission to detect low-frequency gravitational waves on the 0.0001 to 0.1 Hz frequency band. LISA is expected to observe 100's of merging massive black hole binaries out z-15, tens of thousands of close compact binary systems in the Milky Way, merging intermediate-mass black hole binaries, tens of stellar-mass black holes falling into supermassive black holes in galactic centers, and possibly other exotic sources. Several critical LISA technologies have not been demonstrated at the requisite level of performance. In spaceflight, and some fight hardware cannot be tested in a 1-g environment. Hence, the LISA Pathfinder mission is being implemented to demonstrate these critical LISA technologies in a relevant flight environment. LISA Pathfinder mimics one arm of the LISA constellation by shrinking the 5-million-kilometer armlength down to a few tens of centimeters. The experimental concept is to measure the relative separation between two test masses nominally following their own geodesics, and thereby determine the relative residual acceleration between them near 1 mHz, about a decade above the lowest frequency required by LISA. To implement such a concept, disturbances on the test masses must be kept very small by many design features, but chiefly by "drag-free" flight. A drag-free spacecraft follows a free-falling test mass which it encloses, but has no mechanical connection to. The spacecraft senses it's orientation and separation with respect to the proof mass, and its propulsion system is commanded to keep the spacecraft centered about the test mass. Thus, the spacecraft shields the test mass from most external influences, and minimizes the effect of force gradients arising from the spacecraft, and acting on the test mass. LISA Pathfinder will compare the geodesic of one test mass against that of the other. Only a metrology system based on interferometry can achieve the displacement sensitivity. Interferometers monitor the separation of both test masses with a sensitivity comparable to that required by LISA, and using the same technologies. LISA Pathfinder is scheduled to be launched in the first half of 1020 to a Lissajous orbit around the first Sun-Earth Lagrange point, L1. In addition to a complete European technology package (the LISA Technology Package, or LTP), LISA Pathfinder will also carry thrusters and software, known as ST-7, a part of NASA's New Millennium Program.

Bibliographic Instruction Handbook.

ERIC Educational Resources Information Center

Association of Coll. and Research Libraries, Chicago, IL.

Based on the ACRL Guidelines for Bibliographic Instruction, this handbook is intended not only to provide guidance in the development of instruction programs, but also to stimulate discussion within the profession. It consists of the guidelines, five model statements and checklists, a glossary, and a pathfinder. The guidelines present generally…

Pathfinder

NASA Image and Video Library

1994-09-22

This photodepicts a 15 K Fastrac motor ignition test performed at Marshall Test Stand-116. The Fastrac motor is an alternative low-cost engine which is being developed and tested at Marshall. This engine was to eventually be used on an X-34 launchvehicle. The X-34 program was cancelled in 2001.

Concept of Science Data Management for the Korea Pathfinder Lunar Orbiter

NASA Astrophysics Data System (ADS)

Kim, Joo Hyeon

2016-10-01

South Korea has a plan to explore the Moon in 2018 or 2019. For the plan, the Korea Aerospace Research Institute which is a government funded research institute kicked off the Korea Lunar Exploration Development Program in January, 2016 in support of Ministry of Science, ICT and Future Planning, South Korea.As the 1st stage mission of the program, named as the Korea Pathfinder Lunar Orbiter(KPLO), will perform acquisition of high resolution images and science data for investigation of lunar environment as well as the core technology demonstration and validation for space explorations. The scientific instruments consists of three Korean domestic developed science instruments except an imaging instrument and several foreign provided instruments. We are developing a science data management plan to encourage scientific activities using science data acquired by the science instruments.I introduce the Korean domestic developed science instruments and present concept of the science data management plan for data delivery, processing, and distribution for the science instruments.

Pathfinder landing sites at candidate SNC impact ejection sites

NASA Technical Reports Server (NTRS)

Golombek, Matthew P.

1994-01-01

If Mars Pathfinder were able to land at a site on Mars from which the SNC meteorites were ejected by impact, the Pathfinder mission would essentially represent a very inexpensive sample return mission. Geologic units that contain four potential impact craters from which SNC meteorites could have been ejected from Mars are accessible to the Mars Pathfinder lander. Determining that SNC meteorites came from a particular spot on Mars raises the intriguing possibility of using Pathfinder as a sample return mission and providing a radiometric age for the considerably uncertain martian crater-age timescale. Pathfinder instruments are capable of determining if the rock type at the landing site is similar to that of one or more of the SNC meteorites, which would strengthen the hypothesis that the SNC meteorites did, in fact, come from Mars. Unfortunately, instrument observations from Pathfinder are probably not capable of determining if the geologic unit sampled by the lander is definitively the unit from which a SNC meteorite came from as opposed to Mars in general or perhaps a particular region on Mars. This abstract evaluates the possibility of landing at potential SNC ejection sites and the ability of Pathfinder to identify the landing site as the place from which an SNC meteorite came.

Design of the MESUR/pathfinder microrover

NASA Technical Reports Server (NTRS)

Stone, Henry W.

1994-01-01

The use of unmanned robotic vehicles to assist in the exploration of Mars and other planets has been of interest to the National Aeronautics and Space Administration (NASA) for several decades and has been the focus of an ongoing research program at the Jet Propulsion Laboratory (JPL) for a similar period of time. As a result of these research activities, JPL is in the process of designing and building a small (7-9 kg) microrover to be flown aboard the Mars Environmental Survey Mission (MESUR)/Pathfinder spacecraft, which is tentatively to be launched to Mars in late 1997. The microrover will perform a variety of technology experiments designed to provide information critical to the design of future planetary rovers. In addition, the microrover will perform several science and lander related experiments using specialized onboard instruments. To enable the microrover to perform these experiments at selected target areas and at the same time deal with the long time delays (and limited communications bandwidth), a control/navigation approach combining the use of operator-designated waypoints and onboard behavior control has been adopted. The design of the MESUR/Pathfinder microrover and the overall manner in which it is controlled are described herein.

Pathfinder ground preparations prior to altitude record setting flight of 71,500 feet

NASA Technical Reports Server (NTRS)

1997-01-01

Technicians make final adjustments on the solar-powered Pathfinder remotely piloted research aircraft prior to the craft's taking off on a flight which established a new unofficial world's altitude record for both propellor-driven and solar-powered aircraft. The new record of more than 71,500 feet was set during a 14 1/2-hour flight July 7, 1997, from the U.S. Navy's Pacific Missile Range Facility (PMRF) at Barking Sands, Kauai, Hawaii. The new altitude record is subject to verification by the National Aeronautics Association. The Pathfinder took off at 8:34 a.m. HDT, passed its previous record altitude of 67,350 feet about 2:45 p.m., and then reached its new mark at about 4 p.m. Controllers on the ground then initiated a slow decent, and Pathfinder landed seven hours later at 11:05 p.m. HDT. The experimental Boeing Condor remotely-piloted aircraft had held the previous record for propellor-driven craft of 67,028 feet. The Pathfinder had exceeded that height on a previous flight on June 9, 1997, but not by a large enough margin to be considered a new record. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

Tablet and Face-to-Face Hybrid Professional Development: Providing Earth Systems Science Educators Authentic Research Opportunities through The GLOBE Program at Purdue University

NASA Astrophysics Data System (ADS)

Wegner, K.; Branch, B. D.; Smith, S. C.

2013-12-01

The Global Learning and Observations to Benefit the Environment (GLOBE) program is a worldwide hands-on, primary and secondary school-based science and education program (www.globe.gov). GLOBE's vision promotes and supports students, teachers and scientists to collaborate on inquiry-based authentic science investigations of the environment and the Earth system working in close partnership with NASA, NOAA and NSF Earth System Science Projects (ESSP's) in study and research about the dynamics of Earth's environment. GLOBE Partners conduct face-to-face Professional Development in more than 110 countries, providing authentic scientific research experience in five investigation areas: atmosphere, earth as a system, hydrology, land cover, and soil. This presentation will provide a sample for a new framework of Professional Development that was implemented in July 2013 at Purdue University lead by Mr. Steven Smith who has tested GLOBE training materials for future training. The presentation will demonstrate how institutions can provide educators authentic scientific research opportunities through various components, including: - Carrying out authentic research investigations - Learning how to enter their authentic research data into the GLOBE database and visualize it on the GLOBE website - Learn how to access to NASA's Earth System Science resources via GLOBE's new online 'e-Training Program' - Exploring the connections of their soil protocol measurements and the history of the soil in their area through iPad soils app - LIDAR data exposure, Hydrology data exposure

Technology for Future NASA Missions: Civil Space Technology Initiative (CSTI) and Pathfinder

NASA Technical Reports Server (NTRS)

1988-01-01

Information is presented in viewgraph form on a number of related topics. Information is given on orbit transfer vehicles, spacecraft instruments, spaceborne experiments, university/industry programs, spacecraft propulsion, life support systems, cryogenics, spacecraft power supplies, human factors engineering, spacecraft construction materials, aeroassist, aerobraking and aerothermodynamics.

Jenkins Dune

NASA Technical Reports Server (NTRS)

1997-01-01

This image is of a landform informally called Jenkins Dune and is thought to be a small barchan dune. This feature is less than 1 foot (0.3 m) tall and perhaps 2-3 meters wide. Inferred wind direction is from the left to the right. Near the crest of the feature is a demarcation that may represent the exposure of a crust on the sediments; similar features were seen on sediments on the rock Big Joe at the Viking landing site.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

MOC's Highest Resolution View of Mars Pathfinder Landing Site

NASA Technical Reports Server (NTRS)

2000-01-01

[figure removed for brevity, see original site] (A) Mars Pathfinder site, left: April 1998; right: January 2000.

[figure removed for brevity, see original site] (B) top: April 1998; bottom: January 2000.

Can Mars Global Surveyor's 1.5 meter (5 ft) per pixel camera be used to find any evidence as to the fate of the Mars Polar Lander that was lost on December 3, 1999? One way to find out is to look for one of the other Mars landers and determine what, if anything, can be seen. There have been three successful Mars lander missions: Viking 1 (July 1976), Viking 2 (September 1976), and Mars Pathfinder (July 1997). Of these, the location of Mars Pathfinder is known the best because there are several distinct landmarks visible in the lander's images that help in locating the spacecraft. The MGS MOC Operations Team at Malin Space Science Systems has been tasked since mid-December 1999 with looking for the lost Polar Lander. Part of this effort has been to test the capabilities of MOC by taking a picture of the landing site of Mars Pathfinder.

An attempt to photograph the Pathfinder site was made once before, in April 1998, by turning the entire MGS spacecraft so that the camera could point at the known location of the Mars Pathfinder lander. Turning the MGS spacecraft like this is not a normal operation--it takes considerable planning, and disrupts the on-going, normal acquisition of science data. It took 3 attempts to succeed, but on April 22, 1998, MOC acquired the picture seen on the left side of Figure A, above. The three near-by major landmarks that were visible to the Pathfinder's cameras are labeled here (North Peak, Big Crater, Twin Peaks). It was known at the time that this image was not adequate to see the Pathfinder lander because the camera was not in focus and had a resolution of only 3.3 meters (11 ft) per pixel. In this and all other images shown here, north is up. All views of the 1998 MOC image are illuminated from the lower right, all views of the 2000 MOC image are illuminated from the lower left.

As part of the Polar Lander search effort, the Mars Pathfinder site was targeted again in December 1999 and January 2000. Like the 1998 attempt, the spacecraft had to be pointed off of its normal, nadir (straight-down) view. Like history repeating itself, it once again took 3 tries before the Pathfinder landing site was hit. The picture on the right side of Figure A, above, shows the new image that was acquired on January 16, 2000. The white box indicates the location shown in Figure B (above, right). The 1000 m scale bar equals 0.62 miles.

Figure B (above) shows a subsection of both the 1998 image (top, labeled SPO-1-25603) and the 2000 image (bottom, labeled m11-2414) projected at a scale of 3 meters (10 ft) per pixel. At this scale, the differences in camera focus and sunlight illumination angle are apparent, with the January 2000 image being both in focus and having better lighting conditions. In addition, the MGS spacecraft took the 2000 image from a lower altitude than in 1998, thus the image has better spatial resolution overall. The 500 m scale bar is equal to about 547 yards. The white box shows the location of images in Figure C, below.

[figure removed for brevity, see original site] (C) higher-resolution view; left: April 1998; right: January 2000.

[figure removed for brevity, see original site] D) Erroneous, preliminary identification of Mars Pathfinder location in January 2000 image. Subsequent analysis (Figures E & F, below) identified the correct spot.

The third figure (C, above) again shows portions of the April 1998 image (C, left) and January 2000 image (C, right), only this time they have been enlarged to a resolution of 0.75 meters (2.5 ft) per pixel. The intrinsic resolution of the January 2000 image is 1.5 meters (5 ft), so this is a 200% expanded view of the actual M11-02414 image. The circular features in this and the previous images are impact craters in various states of erosion. Some boulders (dark dots) can be seen near the crater in the lower left corner. The texture that runs diagonally across the scene from upper left toward lower right consists of ridges created by the giant floods that washed through the Pathfinder site from Ares and/or Tiu Vallis many hundreds of millions of years ago. These ridges and the troughs between them were also seen by the Pathfinder lander; their crests often covered with boulders and cobbles (which cannot be seen at the resolution of the MOC image). The 100 m scale bar is equal to 109 yards (which can be compared with a 100 yard U.S. football field). The Mars Pathfinder landing site is located near the center of this view.

The fourth picture, Figure D (above), shows a feature that was initially thought to be the Mars Pathfinder lander by MOC investigators. This and the following figures point out just how difficult it is to find a lander on the martian surface using the MGS MOC. Figure D was prepared early in the week following receipt of the new MOC image on January 17, 2000, and for several days it was believed that the lander had been found. As the subsequent two figures will show (E, and F, below), this location appears to be in error. How the features were misidentified is discussed below. Both Figure D and Figure F, showing possible locations of the Pathfinder lander in the MOC image, are enlarged by a factor of three over the intrinsic resolution of that image (that is, to a scale of 0.5 meters or about 1 ft, 7 inch per pixel). The right picture in Figure D shows sight-lines to the large horizon features--Big Crater, Twin Peaks, and North Peak--that were derived by the MOC team by looking at the images taken by the lander in 1997. After placing these lines on the overall image, there appeared to be two features close to the intersection of the sight-lines. Based upon the consistency of the size and shape of the lander as illuminated by sunlight in this image, the northern of the two candidate features (the small 'hump' at the center of both left and right pictures) was considered, at the time, to be the most likely. HOWEVER...

[figure removed for brevity, see original site] (E) Photoclinometry, Topography, and Revised Landing Site Location.

[figure removed for brevity, see original site] (F) Mars Pathfinder Landing Site; lander not resolved by MOC.

Later in the week following acquisition of the January 16, 2000, image (and over the following weekend), there was time for additional analysis to determine whether the rounded hump identified earlier in the week (Figure D, above) was, in fact, the Mars Pathfinder lander. A computer program that estimates relative topography in a MOC image from knowledge of the illumination (called 'shape-from-shading' or photoclinometry) was run to determine which parts of the landing site image are depressions, which are hills, and which are flat surfaces. The picture at the left in Figure E (above) shows the photoclinometry results for the area around the Pathfinder lander. The picture at the center of Figure E shows the same photoclinometry results overlain by an inset of a topographic map of the Pathfinder landing site derived by the U.S. Geological Survey Astrogeology Branch (Flagstaff, Arizona) from photogrammetry (parallax measurements) using images from Pathfinder's own stereo camera. By matching the features seen by MOC with those seen by the Pathfinder (the large arrows are examples of the matching), the location of the lander was refined and is now indicated in the picture on the right side of Figure E. The large, rounded hump previously identified as Pathfinder in Figure D (above), is more likely a large boulder that was seen in Pathfinder's images and named 'Couch' by the Pathfinder science team in 1997.

Figure F is summary of the results of this effort to find Mars Pathfinder: it shows that while the landing site of Mars Pathfinder can be identified, the lander itself cannot be seen. It is too small to be resolved in an image where each pixel acquired by the MOC covers a square of 1.5 meters (5 feet) to a side, given the contrast conditions on Mars and the MOC's ability to discriminate contrast. At this scale, Pathfinder is not much larger than two pixels, and the same is true of the lost Polar Lander.

No evidence has been found in the January 2000 MOC image of the aft portion of Mars Pathfinder's aeroshell or its parachute, either. If the aeroshell is laying on its side, as interpreted from Mars Pathfinder's images, then it would be very difficult to see this from orbit. Because Pathfinder did not image the parachute, it is not known how it may be configured on the surface--it could be wrapped around the aeroshell or a boulder, for example.

This effort to photograph the Mars Pathfinder lander demonstrates that it is extremely difficult to find a lander on the surface of Mars using the Mars Orbiter Camera aboard the MGS spacecraft. This analysis suggests that it is not very likely that the December 1999 Polar Lander will be found by MOC.

The semantic pathfinder: using an authoring metaphor for generic multimedia indexing.

PubMed

Snoek, Cees G M; Worring, Marcel; Geusebroek, Jan-Mark; Koelma, Dennis C; Seinstra, Frank J; Smeulders, Arnold W M

2006-10-01

This paper presents the semantic pathfinder architecture for generic indexing of multimedia archives. The semantic pathfinder extracts semantic concepts from video by exploring different paths through three consecutive analysis steps, which we derive from the observation that produced video is the result of an authoring-driven process. We exploit this authoring metaphor for machine-driven understanding. The pathfinder starts with the content analysis step. In this analysis step, we follow a data-driven approach of indexing semantics. The style analysis step is the second analysis step. Here, we tackle the indexing problem by viewing a video from the perspective of production. Finally, in the context analysis step, we view semantics in context. The virtue of the semantic pathfinder is its ability to learn the best path of analysis steps on a per-concept basis. To show the generality of this novel indexing approach, we develop detectors for a lexicon of 32 concepts and we evaluate the semantic pathfinder against the 2004 NIST TRECVID video retrieval benchmark, using a news archive of 64 hours. Top ranking performance in the semantic concept detection task indicates the merit of the semantic pathfinder for generic indexing of multimedia archives.

Navigation Flight Operations for Mars Pathfinder

NASA Technical Reports Server (NTRS)

Vaughan, Robin M.; Kallemeyn, Pieter H., Jr.; Spencer, David A.; Braun, Robert D.

2004-01-01

On July 4, 1997, Mars Pathfinder became the first spacecraft to land on the surface of Mars in 21 years. Pathfinder was launched on December 4, 1996 and spent seven months en route to the red planet. This report discusses the navigation flight experience for the Mars Pathfinder interplanetary cruise. In particular, orbit determination and maneuver design and execution results are presented. Special emphasis is given to the navigation role in the days and hours leading up to and including the Entry, Descent, and Landing (EDL) phase.

Validating the Usefulness of Combined Japanese GMS Data For Long-Term Global Change Studies

NASA Technical Reports Server (NTRS)

Simpson, James J.; Dodge, James C. (Technical Monitor)

2001-01-01

The primary objectives of the Geostationary Meteorological Satellite (GMS)-5 Pathfinder Project were the following: (1) to evaluate GMS-5 data for sources of error and develop methods for minimizing any such errors in GMS-5 data; (2) to prepare a GMS-5 Pathfinder data set for the GMS-5 Pathfinder Benchmark Period (1 July 95 - 30 June 96); and (3) show the usefulness of the improved Pathfinder data set in at least one geophysical application. All objectives were met.

PEGASO . Polar Explorer for Geomagnetic And other Scientific Observation

NASA Astrophysics Data System (ADS)

Romeo, G.; Di Stefano, G.; Di Felice, F.; Caprara, F.; Iarocci, A.; Peterzen, S.; Masi, S.; Spoto, D.; Ibba, R.; Musso, I.; Dragoy, P.

PEGASO (Polar Explorer for Geomagnetic And other Scientific Observation) program has been created to conduct small experiments in as many disciplines on-board of small stratospheric balloons. PEGASO uses the very low expensive pathfinder balloons. Stratospheric pathfinders are small balloons commonly used to explore the atmospheric circumpolar upper winds and to predict the trajectory for big LDBs (Long Duration Balloons). Installing scientific instruments on pathfinder and using solar energy to power supply the system, we have the opportunity to explorer the Polar Regions, during the polar summer, following circular trajectory. These stratospheric small payload have flown for 14 up to 40 days, measuring the magnetic field of polar region, by means of 3-axis-fluxgate magnetometer. PEGASO payload uses IRIDIUM satellite telemetry (TM). A ground station communicates with one or more payloads to download scientific and house-keeping data and to send commands for ballast releasing, for system resetting and for operating on the separator system at the flight end. The PEGASO missions have been performed from the Svalbard islands with the logistic collaboration of the Andoya Rocket Range and from the Antarctic Italian base. Continuous trajectory predictions, elaborated by Institute of Information Science and Technology (ISTI-CNR), were necessary for the flight safety requirements in the north hemisphere. This light payloads (<10 Kg) are realized by the cooperation between the INGV and the Physics department "La Sapienza" University and it has operated five times in polar areas with the sponsorship of Italian Antarctic Program (PNRA), Italian Space Agency (ASI). This paper summarizes important results about stratospheric missions.

Testing of the LISA pathfinder GRS

NASA Astrophysics Data System (ADS)

Antonucci, Federica; Cavalleri, Antonella; Ciani, Giacomo; Congedo, Giuseppe; Dolesi, Rita; de Marchi, Fabrizio; Ferraioli, Luigi; Hueller, Mauro; Nicolodi, Daniele; Tombolato, David; Vitale, Stefano; Wass, Peter J.; Weber, William J.

The ESA/NASA mission,LISA (Laser Interferometric Space Antenna), will measure gravita-tional waves emitted by astronomical sources, galactic and extra-galactic, at frequencies 10-4 to 10-1 Hz. LISA is a 5-million-km arm-length interferometer whose mirrors are test masses which must be nominally free-falling to a level which does not exceed 3 · 10-15 ms-2 Hz -1/2 in acceleration. LISA Pathfinder is a technology demonstration mission which will show that the relative parasitic acceleration between two masses on one spacecraft can be lower than 3 · 10-14 ms-2 Hz -1/2 , at frequencies around 1 mHz -one order of magnitude larger than LISA's goal. At the core of the LISA Pathfinder experiment is the GRS (gravitational reference sensor), a capacitive sensor with mm gaps used to measure the position of the test mass and actuate its position in 6-degrees-of-freedom. Testing the purity of free-fall for LISA Pathfinder on-ground is achieved using a torsion pendulum which allows us to measure force disturbances at a level relevant to LISA Pathfinder. We will present the latest campaign of tests of the LISA Pathfinder GRS using the 4-test-mass torsion pendulum facility aimed at measuring force-noise sources (responsible for the parasitic acceleration) for LISA Pathfinder in its frequency band. Our GRS , is the LISA Pathfinder flight-model replica, and its testing is crucial in verifying the design and performance of the flight instrument and measuring many of the unwanted disturbances which can limit the performance of LISA and LISA pathfinder. The measurements concern the dependence of the force on the test mass position in the sensor and their electrostatic coupling, electrostatic fields due to surface-potential variations and thermal gradients.

Space Science

NASA Image and Video Library

1996-12-04

The Mars Pathfinder began the journey to Mars with liftoff atop a Delta II expendable launch vehicle from launch Complex 17B on Cape Canaveral Air Station. The Mars Pathfinder traveled on a direct trajectory to Mars, and arrived there in July 1997. Mars Pathfinder sent a lander and small robotic rover, Sojourner, to the surface of Mars. The primary objective of the mission was to demonstrate a low-cost way of delivering a science package to the surface of Mars using a direct entry, descent and landing with the aid of small rocket engines, a parachute, airbags and other techniques. In addition, landers and rovers of the future will share the heritage of Mars Pathfinder designs and technologies first tested in this mission. Pathfinder also collected invaluable data about the Martian surface.

Identification of metabolic pathways using pathfinding approaches: a systematic review.

PubMed

Abd Algfoor, Zeyad; Shahrizal Sunar, Mohd; Abdullah, Afnizanfaizal; Kolivand, Hoshang

2017-03-01

Metabolic pathways have become increasingly available for various microorganisms. Such pathways have spurred the development of a wide array of computational tools, in particular, mathematical pathfinding approaches. This article can facilitate the understanding of computational analysis of metabolic pathways in genomics. Moreover, stoichiometric and pathfinding approaches in metabolic pathway analysis are discussed. Three major types of studies are elaborated: stoichiometric identification models, pathway-based graph analysis and pathfinding approaches in cellular metabolism. Furthermore, evaluation of the outcomes of the pathways with mathematical benchmarking metrics is provided. This review would lead to better comprehension of metabolism behaviors in living cells, in terms of computed pathfinding approaches. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Mars Pathfinder Atmospheric Entry Navigation Operations

NASA Technical Reports Server (NTRS)

Braun, R. D.; Spencer, D. A.; Kallemeyn, P. H.; Vaughan, R. M.

1997-01-01

On July 4, 1997, after traveling close to 500 million km, the Pathfinder spacecraft successfully completed entry, descent, and landing, coming to rest on the surface of Mars just 27 km from its target point. In the present paper, the atmospheric entry and approach navigation activities required in support of this mission are discussed. In particular, the flight software parameter update and landing site prediction analyses performed by the Pathfinder operations navigation team are described. A suite of simulation tools developed during Pathfinder's design cycle, but extendible to Pathfinder operations, are also presented. Data regarding the accuracy of the primary parachute deployment algorithm is extracted from the Pathfinder flight data, demonstrating that this algorithm performed as predicted. The increased probability of mission success through the software parameter update process is discussed. This paper also demonstrates the importance of modeling atmospheric flight uncertainties in the estimation of an accurate landing site. With these atmospheric effects included, the final landed ellipse prediction differs from the post-flight determined landing site by less then 0.5 km in downtrack.

Integrating Subject Pathfinders into Online Catalogs.

ERIC Educational Resources Information Center

Jarvis, William E.

1985-01-01

Discusses the integration of subject pathfinders into online public access catalogs (OPAC) through following features: within the OPAC, offline user guide manuals, remotely printed upon user request, or online as saved searches displayed in help screen format. Excerpts of a pathfinder display for biotechnology are presented. Four sources are…

Global monitoring of Sea Surface Salinity with Aquarius

NASA Technical Reports Server (NTRS)

Lagerloef, G. S. E.; LeVine, D. M.; Chao, Yi; Colomb, R.; Nollmann, I.

2005-01-01

Aquarius is a microwave remote sensing system designed to obtain global maps of the surface salinity field of the oceans from space. It will be flown on the Aquarius/SAC-D mission, a partnership between the USA (NASA) and Argentina (CONAE) with launch scheduled for late in 2008. The objective of Aquarius is to monitor the seasonal and interannual variation of the large scale features of the surface salinity field in the open ocean. This will provide data to address scientific questions associated with ocean circulation and its impact on climate. For example, salinity is needed to understand the large scale thermohaline circulation, driven by buoyancy, which moves large masses of water and heat around the globe. Of the two variables that determine buoyancy (salinity and temperature), temperature is already being monitored. Salinity is the missing variable needed to understand this circulation. Salinity also has an important role in energy exchange between the ocean and atmosphere, for example in the development of fresh water lenses (buoyant water that forms stable layers and insulates water below from the atmosphere) which alter the air-sea coupling. Aquarius is a combination radiometer and scatterometer (radar) operating at L-band (1.413 GHz for the radiometer and 1.26 GHz for the scatterometer). The primary instrument,for measuring salinity is the radiometer which is able to detect salinity because of the modulation salinity produces on the thermal emission from sea water. This change is detectable at the long wavelength end of the microwave spectrum. The scatterometer will provide a correction for surface roughness (waves) which is one of the greatest unknowns in the retrieval. The sensor will be in a sun-synchronous orbit at about 650 km with equatorial crossings of 6am/6pm. The antenna for these two instruments is a 3 meter offset fed reflector with three feeds arranged in pushbroom fashion looking away from the sun toward the shadow side of the orbit to minimize sunglint. The mission goal is to produce maps of the salinity field globally once each month with an accuracy of 0.2 psu and a spatial resolution of 100 km. This will be adequate to address l&ge scale features of the salinity field of the open ocean. The temporal resolution is sufficient to address seasonal changes and a three year mission is planned to-collect sufficient data to look for interannual variation. Aquarius is being developed by NASA as part of the Earth System Science Pathfinder (ESSP) program. The SAC-D mission is being developed by CONAE and will include the space craft and several additional instruments, including visible and infrared cameras and a microwave radiometer to monitor rain and wind velocity over the oceans, and sea ice.

Pathfinder Rear Ramp

NASA Image and Video Library

1997-07-06

NASA's Mars Pathfinder's rear rover ramp can be seen successfully unfurled in this image, taken at the end of Sol 2 by the Imager for Mars Pathfinder (IMP). This ramp was later used for the deployment of the microrover Sojourner, which occurred at the end of Sol 2. Areas of a lander petal and deflated airbag are visible at left. The image helped Pathfinder scientists determine that the rear ramp was the one to use for rover deployment. At upper right is the rock dubbed "Barnacle Bill," which Sojourner will later study. http://photojournal.jpl.nasa.gov/catalog/PIA00627

MESUR Pathfinder Science Investigations

NASA Technical Reports Server (NTRS)

Golombek, M.

1993-01-01

The MESUR (Mars Environmental Survey) Pathfinder mission is the first Discovery mission planned for launch in 1996. MESUR Pathfinder is designed as an engineering demonstration of the entry, descent and landing approach to be employed by the follow-on MESUR Network mission, which will land of order 10 small stations on the surface of Mars to investigate interior, atmospheric and surface properties. Pathfinder is a small Mars lander, equipped with a microrover to deploy instruments and explore the local landing site. Instruments selected for Pathfinder include a surface imager on a 1 m pop-up mast (stereo with spectral filters), an atmospheric structure instrument/surface meteorology package, and an alpha proton x-ray spectrometer. The microrover will carry the alpha proton x-ray spectrometer to a number of different rocks and surface materials and provide close-up imaging...

KSC-2009-1498

NASA Image and Video Library

2009-01-26

VANDENBERG AIR FORCE BASE, Calif. -- The avionics are mated to stage 2 of the Taurus XL launch vehicle for the Orbiting Carbon Observatory at Vandenberg Air Force Base in California. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The launch of OCO is scheduled for Feb. 23. Photo credit: NASA/VAFB

A Resource Guide for Oceanography and Coastal Processes.

ERIC Educational Resources Information Center

Walker, Sharon H., Ed.; Damon-Randall, Kimberly, Ed.; Walters, Howard D., Ed.

This resource guide was developed for elementary, middle, and high school teachers to teach about oceanography and coastal processes. This guide contains information on the program's history and names and contact information for all Operation Pathfinder participants since 1993. The body is divided into 6 topics. Topic 1 is on Physical Parameters,…

Northeast View From Pathfinder Lander

NASA Technical Reports Server (NTRS)

1997-01-01

This panorama of the region to the northeast of the lander was constructed to support the Sojourner Rover Team's plans to conduct an 'autonomous traverse' to explore the terrain away from the lander after science objectives in the lander vicinity had been met. The large, relatively bright surface in the foreground, about 10 meters (33 feet) from the spacecraft, in this scene is 'Baker's Bench.' The large, elongated rock left of center in the middle distance is 'Zaphod.'

This view was produced by combining 8 individual 'Superpan' scenes from the left and right eyes of the IMP camera. Each frame consists of 8 individual frames (left eye) and 7 frames (right eye) taken with different color filters that were enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution panchromatic frame that is sharper than an individual frame would be.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Twin Peaks (B/W)

NASA Technical Reports Server (NTRS)

1997-01-01

The Twin Peaks are modest-size hills to the southwest of the Mars Pathfinder landing site. They were discovered on the first panoramas taken by the IMP camera on the 4th of July, 1997, and subsequently identified in Viking Orbiter images taken over 20 years ago. The peaks are approximately 30-35 meters (-100 feet) tall. North Twin is approximately 860 meters (2800 feet) from the lander, and South Twin is about a kilometer away (3300 feet). The scene includes bouldery ridges and swales or 'hummocks' of flood debris that range from a few tens of meters away from the lander to the distance of the South Twin Peak. The large rock at the right edge of the scene is nicknamed 'Hippo'. This rock is about a meter (3 feet) across and 25 meters (80 feet) distant.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Reduction and Analysis of Meteorology Data from the Mars Pathfinder Lander

NASA Technical Reports Server (NTRS)

Murphy, James R.; Bridger, Alison F. C.; Haberle, Robert M.

1998-01-01

Dr. James Murphy is a member of the Mars Pathfinder Atmospheric Structure Investigation Meteorology (ASI/MET) Science Team. The activities of Dr. Murphy, and his collaborators are summarized in this report, which reviews the activities in support of the analysis of the meteorology data from the Mars Pathfinder Lander.

MARS PATHFINDER PYRO SYSTEMS SWITCHING ACTIVITY

NASA Technical Reports Server (NTRS)

1996-01-01

The Mars Pathfinder lander is subjected to a electrical and functional tests of its pyrotechic petal deployer system by Jet Propulsion Laboratory (JPL) engineers and technicians in KSC's Spacecraft Assembly and Encapsulation Facility (SAEF-2). In the background is the Pathfinder cruise stage, which the lander will be mated to once its functional tests are complete. The lander will remain attached to this stage during its six-to-seven-month journey to Mars. When the lander touches down on the surface of Mars next year, the pyrotechnic system will deploy its three petals open like a flower and allow the Sojourner autonomous rover to explore the Martian surface. The Mars Pathfinder is scheduled for launch aboard a Delta II expendable launch vehicle on Dec. 2, the beginning of a 24-day launch period. JPL is managing the Mars Pathfinder project for NASA.

Terrain at Landing Site

NASA Image and Video Library

1997-07-05

Portions of Mars Pathfinder's deflated airbags (seen in the foreground), a large rock in mid-field, and a hill in the background were taken by the Imager for Mars Pathfinder (IMP) aboard Mars Pathfinder during the spacecraft's first day on the Red Planet. Pathfinder successfully landed on Mars at 10:07 a.m. PDT earlier today. The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per "eye." It stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters. http://photojournal.jpl.nasa.gov/catalog/PIA00615

A review of parameters and heuristics for guiding metabolic pathfinding.

PubMed

Kim, Sarah M; Peña, Matthew I; Moll, Mark; Bennett, George N; Kavraki, Lydia E

2017-09-15

Recent developments in metabolic engineering have led to the successful biosynthesis of valuable products, such as the precursor of the antimalarial compound, artemisinin, and opioid precursor, thebaine. Synthesizing these traditionally plant-derived compounds in genetically modified yeast cells introduces the possibility of significantly reducing the total time and resources required for their production, and in turn, allows these valuable compounds to become cheaper and more readily available. Most biosynthesis pathways used in metabolic engineering applications have been discovered manually, requiring a tedious search of existing literature and metabolic databases. However, the recent rapid development of available metabolic information has enabled the development of automated approaches for identifying novel pathways. Computer-assisted pathfinding has the potential to save biochemists time in the initial discovery steps of metabolic engineering. In this paper, we review the parameters and heuristics used to guide the search in recent pathfinding algorithms. These parameters and heuristics capture information on the metabolic network structure, compound structures, reaction features, and organism-specificity of pathways. No one metabolic pathfinding algorithm or search parameter stands out as the best to use broadly for solving the pathfinding problem, as each method and parameter has its own strengths and shortcomings. As assisted pathfinding approaches continue to become more sophisticated, the development of better methods for visualizing pathway results and integrating these results into existing metabolic engineering practices is also important for encouraging wider use of these pathfinding methods.

Pathfinder-Plus flight in Hawaii

NASA Technical Reports Server (NTRS)

2002-01-01

Pathfinder-Plus flight in Hawaii June 2002 AeroVironment's Pathfinder-Plus solar-powered flying wing recently flew a three-flight demonstration of its ability to relay third-generation cell phone and video signals as well as provide Internet linkage. The two pods underneath the center section of the wing carried the advanced two-way telecom package, developed by Japanese telecommunications interests.

Gambling on the Protestants: the Pathfinder Fund and birth control in Peru, 1958-1965.

PubMed

López, L Necochea

2014-01-01

Among the agencies involved in population control activities in the mid-twentieth century, none scored as many early victories in Latin America as did the Pathfinder Fund, founded by Procter & Gamble scion Clarence Gamble. This article analyzes a style in the delivery of family planning assistance in the developing world through the work of the Pathfinder Fund in Peru, the organization's hub in South America, and shows how Pathfinder personnel collaborated with local Protestant institutions. Its Protestant allies helped Pathfinder set up and manage rapid interventions such as the production of pamphlets, the smuggling of contraceptives, and the enrollment of physicians as advocates of the use of intrauterine devices. Although these rapid interventions helped quickly disseminate information and certain technologies among a fortunate few, they also weakened legitimate state agencies, neglected the monitoring of the safety of the drugs supplied, and alienated allies with their high-handed boldness.

LISA Pathfinder: An important first step towards a space-based gravitational wave observatory

NASA Astrophysics Data System (ADS)

Thorpe, James

2017-08-01

ESA's LISA Pathfinder mission was launched on Dec 3rd, 2015 and completed earlier this Summer. During this relatively short mission, Pathfinder at its two science payloads, Europe's LISA Technology Package and NASA's Disturbance Reduction System, demonstrated several techniques and technologies that enable development of a future space-based gravitational wave observatory. Most notably, Pathfinder demonstrated that the technique of drag-free flight could be utilized to place a test mass in near-perfect free-fall, with residual accelerations at the femto-g level in the milliHertz band. Additionally, technologies such as precision bonded optical structures for metrology, micropropulsion systems, and non-contact charge control, were successfully tested, retiring risk for LISA. In this talk, I will present an overview of Pathfinder's results to date and some perspective on how this success will be leveraged into realizing LISA.

Sojourner Sits Near Rock Garden

NASA Technical Reports Server (NTRS)

2003-01-01

The Mars Pathfinder Rover Sojourner is images by the Imager for Mars Pathfinder as it nears the rock 'Wedge.' Part of the Rock Garden is visible in the upper right of the image.

Pathfinder, a low-cost Discovery mission, is the first of a new fleet of spacecraft that are planned to explore Mars over the next ten years. Mars Global Surveyor, already en route, arrives at Mars on September 11 to begin a two year orbital reconnaissance of the planet's composition, topography, and climate. Additional orbiters and landers will follow every 26 months.

The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Pathfinder aircraft flight #1

NASA Image and Video Library

1996-11-19

The Pathfinder research aircraft's solar cell arrays are prominently displayed as it touches down on the bed of Rogers Dry Lake at the Dryden Flight Research Center, Edwards, California, following a test flight. The solar arrays covered more than 75 percent of Pathfinder's upper wing surface, and provided electricity to power its six electric motors, flight controls, communications links and a host of scientific sensors.

Mars Pathfinder Landing Site Workshop

NASA Technical Reports Server (NTRS)

Golombek, Matthew (Editor)

1994-01-01

The Mars Pathfinder Project is an approved Discovery-class mission that will place a lander and rover on the surface of the Red Planet in July 1997. The Mars Pathfinder Landing Site Workshop was designed to allow the Mars scientific community to provide input as to where to land Pathfinder on Mars. The workshop was attended by over 60 people from around the United States and from Europe. Over 20 landing sites were proposed at the workshop, and the scientific questions and problems concerning each were addressed. The workshop and the discussion that occured during and afterward have significantly improved the ability to select a scientifically exciting but safe landing site on Mars.

Visible and Near-Infrared Properties of Optical Fibers Coupled to the Pathfinder High-Resolution NIR Spectrograph

NASA Astrophysics Data System (ADS)

McCoy, K.; Ramsey, L.

2011-09-01

The Penn State Astronomy and Astrophysics Department’s Pathfinder instrument is a fiber-fed, warm-bench echelle spectrograph designed to explore technical issues that must be resolved in order to measure precise radial velocities that will allow the detection of exoplanets in the near-infrared (NIR). In May 2010, Pathfinder demonstrated 10-20 m/s radial-velocity precision in the NIR at the 9 meter Hobby-Eberly Telescope. To attain even higher precision, we are investigating the NIR properties of the optical fibers that transmit light from the telescope to Pathfinder. We conducted a series of modal noise tests with visible and NIR laser diodes on a 200 micron diameter, fused-silica, multimode optical fiber as the preliminary step in analyzing the degrading effects of modal noise on radial-velocity precision. We report these test results and comment on our future tests to reduce the negative effects of modal noise and focal ratio degradation (FRD). The lessons learned from this research and the Pathfinder prototype will be used in Pathfinder II, which will aim to achieve better than 5 m/s in the NIR.

Statechart Analysis with Symbolic PathFinder

NASA Technical Reports Server (NTRS)

Pasareanu, Corina S.

2012-01-01

We report here on our on-going work that addresses the automated analysis and test case generation for software systems modeled using multiple Statechart formalisms. The work is motivated by large programs such as NASA Exploration, that involve multiple systems that interact via safety-critical protocols and are designed with different Statechart variants. To verify these safety-critical systems, we have developed Polyglot, a framework for modeling and analysis of model-based software written using different Statechart formalisms. Polyglot uses a common intermediate representation with customizable Statechart semantics and leverages the analysis and test generation capabilities of the Symbolic PathFinder tool. Polyglot is used as follows: First, the structure of the Statechart model (expressed in Matlab Stateflow or Rational Rhapsody) is translated into a common intermediate representation (IR). The IR is then translated into Java code that represents the structure of the model. The semantics are provided as "pluggable" modules.

X-34 Poster Art

NASA Technical Reports Server (NTRS)

2004-01-01

Pictured is NASA's poster art for the X-34 technology Demonstrator. The X-34 was part of NASA's Pathfinder Program which demonstrated advanced space transportation technologies through the use of flight experiments and experimental vehicles. These technology demonstrators and flight experiments would support the Agency's goal of dramatically reducing the cost of access to space and would define the future of space transportation pushing technology into a new era of space development and exploration at the dawn of the new century. The X-34 program was cancelled in 2001.

Pathfinder

NASA Image and Video Library

1997-06-04

A close-up view of Bantam duration testing of the 40K Fastrac II Engine for X-34 at Marshall Space Flight Center's (MSFC) test stand 116. The Bantam test refers to the super lightweight engines of the Fastrac program. The engines were designed as part of the low cost X-34 Reusable Launch Vehicle (RLV). The testing of these engines at MSFC allowed the engineers to determine the capabilities of these engines and the metal alloys that were used in their construction. The Fastrac and X-34 programs were cancelled in 2001.

The X-34 Demonstrator Landing

NASA Technical Reports Server (NTRS)

2004-01-01

This artist's concept depicts the X-34 Demonstrator landing in a dessert. Part of the Pathfinder Program, the X-34 was a reusable technology testbed vehicle that was designed and built by the Marshall Space Flight Center to demonstrate technologies that were essential to lowering the cost of access to space. Powered by a LOX and RP-1 liquid Fastrac engine, the X-34 would be capable of speeds up to Mach 8 and altitudes of 250,000-feet. The X-34 program was cancelled in 2001.

Scalability, Interoperability, and Security at the Data Discovery Level: A System Administrator's Perspective

NASA Technical Reports Server (NTRS)

2006-01-01

The Global Change Master Directory (GCMD) has been one of the best known Earth science and global change data discovery online resources throughout its extended operational history. The growing popularity of the system since its introduction on the World Wide Web in 1994 has created an environment where resolving issues of scalability, security, and interoperability have been critical to providing the best available service to the users and partners of the GCMD. Innovative approaches developed at the GCMD in these areas will be presented with a focus on how they relate to current and future GO-ESSP community needs.

Martian Surface & Pathfinder Airbags

NASA Image and Video Library

1997-07-05

This image of the Martian surface was taken in the afternoon of Mars Pathfinder's first day on Mars. Taken by the Imager for Mars Pathfinder (IMP camera), the image shows a diversity of rocks strewn in the foreground. A hill is visible in the distance (the notch within the hill is an image artifact). Airbags are seen at the lower right. http://photojournal.jpl.nasa.gov/catalog/PIA00612

Motoneuron axon pathfinding errors in zebrafish: Differential effects related to concentration and timing of nicotine exposure

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

Menelaou, Evdokia; Paul, Latoya T.; Perera, Surangi N.

Nicotine exposure during embryonic stages of development can affect many neurodevelopmental processes. In the developing zebrafish, exposure to nicotine was reported to cause axonal pathfinding errors in the later born secondary motoneurons (SMNs). These alterations in SMN axon morphology coincided with muscle degeneration at high nicotine concentrations (15–30 μM). Previous work showed that the paralytic mutant zebrafish known as sofa potato exhibited nicotine-induced effects onto SMN axons at these high concentrations but in the absence of any muscle deficits, indicating that pathfinding errors could occur independent of muscle effects. In this study, we used varying concentrations of nicotine at differentmore » developmental windows of exposure to specifically isolate its effects onto subpopulations of motoneuron axons. We found that nicotine exposure can affect SMN axon morphology in a dose-dependent manner. At low concentrations of nicotine, SMN axons exhibited pathfinding errors, in the absence of any nicotine-induced muscle abnormalities. Moreover, the nicotine exposure paradigms used affected the 3 subpopulations of SMN axons differently, but the dorsal projecting SMN axons were primarily affected. We then identified morphologically distinct pathfinding errors that best described the nicotine-induced effects on dorsal projecting SMN axons. To test whether SMN pathfinding was potentially influenced by alterations in the early born primary motoneuron (PMN), we performed dual labeling studies, where both PMN and SMN axons were simultaneously labeled with antibodies. We show that only a subset of the SMN axon pathfinding errors coincided with abnormal PMN axonal targeting in nicotine-exposed zebrafish. We conclude that nicotine exposure can exert differential effects depending on the levels of nicotine and developmental exposure window. - Highlights: • Embryonic nicotine exposure can specifically affect secondary motoneuron axons in a dose-dependent manner. • The nicotine-induced secondary motoneuron axonal pathfinding errors can occur independent of any muscle fiber alterations. • Nicotine exposure primarily affects dorsal projecting secondary motoneurons axons. • Nicotine-induced primary motoneuron axon pathfinding errors can influence secondary motoneuron axon morphology.« less

Using EarthScope Construction of the Plate Boundary Observatory to Provide Locally Based Experiential Education and Outreach

NASA Astrophysics Data System (ADS)

Jackson, M.; Eriksson, S.; Barbour, K.; Venator, S.; Mencin, D.; Prescott, W.

2006-12-01

EarthScope is an NSF-funded, national science initiative to explore the structure and evolution of the North American continent and to understand the physical processes controlling earthquakes and volcanoes. This large-scale experiment provides locally based opportunities for education and outreach which engage students at various levels and the public. UNAVCO is responsible for the Plate Boundary Observatory (PBO) component of EarthScope. PBO includes the installation and operations and maintenance of large networks of Global Positioning Satellite (GPS), strainmeter, seismometer, and tiltmeter instruments and the acquisition of satellite radar imagery, all of which will be used to measure and map the smallest movements across faults, the magma movement inside active volcanoes and the very wide areas of deformation associated with plate tectonic motion. UNAVCO, through its own education and outreach activities and in collaboration with the EarthScope E&O Program, uses the PBO construction activities to increase the understanding and public appreciation of geodynamics, earth deformation processes, and their relevance to society. These include programs for public outreach via various media, events associated with local installations, a program to employ students in the construction of PBO, and development of curricular materials by use in local schools associated with the EarthScope geographic areas of focus. PBO provides information to the media to serve the needs of various groups and localities, including interpretive centers at national parks and forests, such as Mt. St. Helens. UNAVCO staff contributed to a television special with the Spanish language network Univision Aquí y Ahora program focused on the San Andreas Fault and volcanoes in Alaska. PBO participated in an Education Day at the Pathfinder Ranch Science and Outdoor Education School in Mountain Center, California. Pathfinder Ranch hosts two of the eight EarthScope borehole strainmeters in the Anza region to study the area between the San Andreas Fault and the San Jacinto Fault. The event provided an opportunity for the Pathfinder Ranch to unveil the instruments and describe the important science behind the project to the school's students, staff, and board members. The two strainmeters will be used as a teaching tool for several years as hundreds of students filter through Pathfinder school. UNAVCO sponsors a summer PBO Student Field Assistant Program designed to give students from a variety of educational backgrounds the opportunity get involved in the construction of the EarthScope PBO project. The goal of the program is to excite students about the geodetic sciences through direct work experience. Over the summers of 2005 and 2006, PBO sponsored a total of 11 student assistants who helped to install GPS and strainmeter stations and to perform operations and maintenance tasks. PBO plans to expand this program in 2007 by including student assistants in our data management and strainmeter data processing activities. In August, 2006, UNAVCO led a group of scientists, teachers, and curriculum developers to identify key scientific concepts of EarthScope research and how they can be translated into the Earth Science classroom at the middle and high school levels. The focus was on the Cascadia region. A feature of the workshop was to use PBO and USArray data in the classroom.

JWST Pathfinder Telescope Integration

NASA Technical Reports Server (NTRS)

Matthews, Gary W.; Kennard, Scott H.; Broccolo, Ronald T.; Ellis, James M.; Daly, Elizabeth A.; Hahn, Walter G.; Amon, John N.; Mt. Pleasant, Stephen M.; Texter, Scott; Atkinson, Charles B.;

Weathering of rock 'Ginger'

NASA Technical Reports Server (NTRS)

1997-01-01

One of the more unusual rocks at the site is Ginger, located southeast of the lander. Parts of it have the reddest color of any material in view, whereas its rounded lobes are gray and relatively unweathered. These color differences are brought out in the inset, enhanced at the upper right. In the false color image at the lower right, the shape of the visible-wavelength spectrum (related to the abundance of weathered ferric iron minerals) is indicated by the hue of the rocks. Blue indicates relatively unweathered rocks. Typical soils and drift, which are heavily weathered, are shown in green and flesh tones. The very red color in the creases in the rock surface correspond to a crust of ferric minerals. The origin of the rock is uncertain; the ferric crust may have grown underneath the rock, or it may cement pebbles together into a conglomerate. Ginger will be a target of future super-resolution studies to better constrain its origin.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

Mars Navigator: An Interactive Multimedia Program about Mars, Aerospace Engineering, Astronomy, and the JPL Mars Missions. [CD-ROM

ERIC Educational Resources Information Center

Gramoll, Kurt

This CD-ROM introduces basic astronomy and aerospace engineering by examining the Jet Propulsion Laboratory's (JPL) Mars Pathfinder and Mars Global Surveyor missions to Mars. It contains numerous animations and narrations in addition to detailed graphics and text. Six interactive laboratories are included to help understand topics such as the…

Pathfinder

NASA Image and Video Library

1966-05-21

The Delta Clipper-Experimental Advanced (DC-XA) is a single-stage-to-orbit, vertical takeoff / vertical landing launch vehicle concept, whose development was geared to significantly reduce launch cost and provided a test bed for NASA Reusable Launch Vehicle (RLV) technology. This photograph shows the descending vehicle landing during the first successful test flight at White Sands Missile Range, New Mexico. The program was discontinued in 2003.

Mars Pathfinder Spacecraft, Lander, and Rover Testing in Simulated Deep Space and Mars Surface Environments

NASA Technical Reports Server (NTRS)

Johnson, Kenneth R.

1997-01-01

The Mars Pathfinder (MPF) Spacecraft was built and tested at the Jet Propulsion Laboratory during 1995/96. MPF is scheduled to launch in December 1996 and to land on Mars on July 4, 1997. The testing program for MPF required subjecting the mission hardware to both deep space and Mars surface conditions. A series of tests were devised and conducted from 1/95 to 7/96 to study the thermal response of the MPF spacecraft to the environmental conditions in which it will be exposed during the cruise phase (on the way to Mars) and the lander phase (landed on Mars) of the mission. Also, several tests were conducted to study the thermal characteristics of the Mars rover, Sojourner, under Mars surface environmental conditions. For these tests, several special test fixtures and methods were devised to simulate the required environmental conditions. Creating simulated Mars surface conditions was a challenging undertaking since Mars' surface is subjected to diurnal cycling between -20 C and -85 C, with windspeeds to 20 m/sec, occurring in an 8 torr CO2 atmosphere. This paper describes the MPF test program which was conducted at JPL to verify the MPF thermal design.

NAS-current status and future plans

NASA Technical Reports Server (NTRS)

Bailey, F. R.

1987-01-01

The Numerical Aerodynamic Simulation (NAS) has met its first major milestone, the NAS Processing System Network (NPSN) Initial Operating Configuration (IOC). The program has met its goal of providing a national supercomputer facility capable of greatly enhancing the Nation's research and development efforts. Furthermore, the program is fulfilling its pathfinder role by defining and implementing a paradigm for supercomputing system environments. The IOC is only the begining and the NAS Program will aggressively continue to develop and implement emerging supercomputer, communications, storage, and software technologies to strengthen computations as a critical element in supporting the Nation's leadership role in aeronautics.

Pathfinder aircraft liftoff on altitude record setting flight of 71,500 feet

NASA Image and Video Library

1997-07-07

The Pathfinder aircraft has set a new unofficial world record for high-altitude flight of over 71,500 feet for solar-powered aircraft at the U.S. Navy's Pacific Missile Range Facility, Kauai, Hawaii. Pathfinder was designed and manufactured by AeroVironment, Inc, of Simi Valley, California, and was operated by the firm under a jointly sponsored research agreement with NASA's Dryden Flight Research Center, Edwards, California. Pathfinder's record-breaking flight occurred July 7, 1997. The aircraft took off at 11:34 a.m. PDT, passed its previous record altitude of 67,350 feet at about 5:45 p.m. and then reached its new record altitude at 7 p.m. The mission ended with a perfect nighttime landing at 2:05 a.m. PDT July 8. The new record is the highest altitude ever attained by a propellor-driven aircraft. Before Pathfinder, the altitude record for propellor-driven aircraft was 67,028 feet, set by the experimental Boeing Condor remotely piloted aircraft.

Morning Martian Atmospheric Temperature Gradients and Fluctuations Observed by Mars Pathfinder

NASA Technical Reports Server (NTRS)

Mihalov, John D.; Haberle, R. M.; Murphy, J. R.; Seiff, A.; Wilson, G. R.

1999-01-01

We have studied the most prominent atmospheric temperature fluctuations observed during Martian mornings by Mars Pathfinder and have concluded, based on comparisons with wind directions, that they appear to be a result of atmospheric heating associated with the Lander spacecraft. Also, we have examined the morning surface layer temperature lapse rates, which are found to decrease as autumn approaches at the Pathfinder location, and which have mean (and median) values as large as 7.3 K/m in the earlier portions of the Pathfinder landed mission. It is plausible that brief isolated periods with gradients twice as steep are associated with atmospheric heating adjacent to Lander air bag material. In addition, we have calculated the gradient with height of the structure function obtained with Mars Pathfinder, for Mars' atmospheric temperatures measured within about 1.3 m from the surface, assuming a power law dependence, and have found that these gradients superficially resemble those reported for the upper region of the terrestrial stable boundary layer.

Ventifacts at the Pathfinder landing site

USGS Publications Warehouse

Bridges, N.T.; Greeley, R.; Haldemann, A.F.C.; Herkenhoff, K. E.; Kraft, M.; Parker, T.J.; Ward, A.W.

1999-01-01

About half of the rocks at the Mars Pathfinder Ares Vallis landing site appear to be ventifacts, rocks abraded by windborne particles. Comparable resolution images taken by the Imager for Mars Pathfinder (IMP) camera and the Viking landers show that ventifacts are more abundant at the Pathfinder site. The ventifacts occur in several forms, including rocks with faceted edges, finger-like projections, elongated pits, flutes, grooves, and possible rills. The trends of elongated pits, flutes, grooves, and rills cluster at ???280-330?? clockwise from north and generally dip 10-30?? away from their trend direction. These orientations are indicative of southeast to northwest winds and differ from the trend of wind tails at the landing site, the direction of local wind streaks, and predictions of the Global Circulation Model, all of which indicate northeast to southwest winds. The disparity between these data sets strongly suggests that local circulation patterns have changed since the abrasion of the ventifacted rocks. The greater number of ventifacts at the Pathfinder site compared to either of the Viking sites is most easily explained as being due to a larger supply of abrading particles, composed of either sand-sized grains or indurated dust aggregates, and higher surface roughness, which should increase the momentum of saltating grains. The Pathfinder ventifacts may have formed shortly after the deposition of outflow channel sediments nearly 2 Gry ago, when a large local supply of abrading particles should have been abundant and atmospheric conditions may have been more conducive to rock abrasion from saltating grains. Based on how ventifacts form on Earth, the several ventifact forms seen at the Pathfinder site and their presence on some rocks but not on others are probably due to local airflow conditions, original rock shape, exposure duration, rock movement, and to a lesser extent, rock lithology. The abundance of ventifacts at the Pathfinder site, together with other evidence of weathering, indicates that unaltered rock surfaces are rare on Mars. Copyright 1999 by the American Geophysical Union.

Rock and Soil Types at Pathfinder Landing Site

NASA Technical Reports Server (NTRS)

1997-01-01

Type areas of rocks and soils. (A) Dark rock type and bright soil type: Shown is the dark rock Barnacle Bill. Reflectance spectra typical of fresh basalt and APXS spectra indicating more silica-rich basaltic andesite compositions characterize this type. These rocks are typically the small boulders and intermediate-sized cobbles at the Pathfinder site. The bright soil type is very common and in this case comprises Barnacle Bill's wind tail and much of the surround soil area. This soil has a high reflectance and a strongly reddened spectrum indicative of oxidized ferric minerals. (B) Bright rock type: Shown is the bright rock Wedge. Reflectance spectra typical of weathered basalt and APXS spectra indicating basaltic compositions characterize this type. These rocks are typically larger than 1 meter in diameter and many display morphologies indicating flood deposition. (C) Pink rock type: Shown is the pink rock Scooby Doo. APXS and reflectance spectra indicate a composition and optical characteristics similar to the drift soil. However, the morphology of the pink rock type indicates a cemented or rocklike structure. This material may be a chemically cemented hardpan that underlies much of the Pathfinder site. (D) Dark soil type: The dark soil type is typically found on the windward sides of rocks or in rock-free areas like Photometry Flats (shown here) where the bright soil has been striped away by aeolian action or in open areas. Other locations include the Mermaid Dune. (E) Disturbed soil type: The darkening of disturbed soil relative to its parent material, bright soil, as a result of changes in soil texture and compaction caused by movement of the rover and retraction of the lander airbag. (F) Lamb-like soil type: This soil type shows reflectance and spectral characteristics intermediate between the bright and dark soils. Its distinguishing feature is a weak spectral absorption near 900 nanometers not seen in either the bright or dark soils.

NOTE: original caption as published in Science Magazine

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

First look at rock & soil properties

NASA Technical Reports Server (NTRS)

1997-01-01

The earliest survey of spectral properties of the rocks and soils surrounding Pathfinder was acquired as a narrow strip covering the region just beyond the where the rover made its egress from the lander. The wavelength filters used, all in the binocular camera's right eye, cover mainly visible wavelengths. These data reveal at least five kinds of rocks and soil in the immediate vicinity of the lander. All of the spectra are ratioed to the mean spectrum of bright red drift to highlight the differences. Different occurrences of drift (pink spectra) are closely similar. Most of the rocks (black spectra) have a dark gray color, and are both darker and less red than the drift, suggesting less weathering. Typical soils (green spectra) are intermediate in properties to the rocks and drift. Both these data and subsequent higher resolution images show that the typical soil consists of a mixture of drift and small dark gray particles resembling the rock. However, two other kinds of materials are significantly different from the rocks and drift. Pinkish or whitish pebbles and crusts on some of the rocks (blue spectra) are brighter in blue light and darker in near-infrared light than is the drift, and they lack the spectral characteristics closely associated with iron minerals. Dark red soils in the lee of several rocks are about as red as the drift, but consistently darker. The curvature in the spectrum at visible wavelengths suggests either more ferric iron minerals than in the drift or a larger particle size.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

EOS Reference Handbook 1999: A Guide to NASA's Earth Science Enterprise and the Earth Observing System

NASA Technical Reports Server (NTRS)

King, M. D. (Editor); Greenstone, R. (Editor)

2000-01-01

The content of this handbook includes Earth Science Enterprise; The Earth Observing System; EOS Data and Information System (EOSDIS); Data and Information Policy; Pathfinder Data Sets; Earth Science Information Partners and the Working Prototype-Federation; EOS Data Quality: Calibration and Validation; Education Programs; International Cooperation; Interagency Coordination; Mission Elements; EOS Instruments; EOS Interdisciplinary Science Investigations; and Points-of-Contact.

Motoneuron axon pathfinding errors in zebrafish: Differential effects related to concentration and timing of nicotine exposure

PubMed Central

Menelaou, Evdokia; Paul, Latoya T.; Perera, Surangi N.; Svoboda, Kurt R.

2015-01-01

Nicotine exposure during embryonic stages of development can affect many neurodevelopmental processes. In the developing zebrafish, exposure to nicotine was reported to cause axonal pathfinding errors in the later born secondary motoneurons (SMN). These alterations in SMN axon morphology coincided with muscle degeneration at high nicotine concentrations (15–30µM). Previous work showed that the paralytic mutant zebrafish known as sofa potato, exhibited nicotine-induced effects onto SMN axons at these high concentrations but in the absence of any muscle deficits, indicating that pathfinding errors could occur independent of muscle effects. In this study, we used varying concentrations of nicotine at different developmental windows of exposure to specifically isolate its effects onto subpopulations of motoneuron axons. We found that nicotine exposure can affect SMN axon morphology in a dose-dependent manner. At low concentrations of nicotine, SMN axons exhibited pathfinding errors, in the absence of any nicotine-induced muscle abnormalities. Moreover, the nicotine exposure paradigms used affected the 3 subpopulations of SMN axons differently, but the dorsal projecting SMN axons were primarily affected. We then identified morphologically distinct pathfinding errors that best described the nicotine-induced effects on dorsal projecting SMN axons. To test whether SMN pathfinding was potentially influenced by alterations in the early born primary motoneuron (PMN), we performed dual labeling studies, where both PMN and SMN axons were simultaneously labeled with antibodies. We show that only a subset of the SMN axon pathfinding errors coincided with abnormal PMN axonal targeting in nicotine-exposed zebrafish. We conclude that nicotine exposure can exert differential effects depending on the levels of nicotine and developmental exposure window. PMID:25668718

MARS PATHFINDER INSPECTED BY ENGINEER LINDA ROBECK IN SAEF-2

NASA Technical Reports Server (NTRS)

1996-01-01

In the SAEF-2 spacecraft checkout facility, engineer Linda Robeck of the Jet Propulsion Laboratory inspects the Mars Pathfinder lander. The spacecraft arrived at Kennedy Space Center from Pasadena, CA on Aug. 13, 1996. The petals of the lander will be opened for checkout of the spacecraft and the installation of the small rover. Launch of Mars Pathfinder aboard a McDonnell Douglas Delta II rocket will occur from Pad B at Complex 17 on Dec. 2.

Lessons Learned from NASA UAV Science Demonstration Program Missions

NASA Technical Reports Server (NTRS)

Wegener, Steven S.; Schoenung, Susan M.

2003-01-01

During the summer of 2002, two airborne missions were flown as part of a NASA Earth Science Enterprise program to demonstrate the use of uninhabited aerial vehicles (UAVs) to perform earth science. One mission, the Altus Cumulus Electrification Study (ACES), successfully measured lightning storms in the vicinity of Key West, Florida, during storm season using a high-altitude Altus(TM) UAV. In the other, a solar-powered UAV, the Pathfinder Plus, flew a high-resolution imaging mission over coffee fields in Kauai, Hawaii, to help guide the harvest.

X-34 Technology Demonstrator in High Bay

NASA Technical Reports Server (NTRS)

2004-01-01

Pictured in the high bay, is the X-34 Technology Demonstrator in the process of completion. The X-34 wass part of NASA's Pathfinder Program which demonstrated advanced space transportation technologies through the use of flight experiments and experimental vehicles. These technology demonstrators and flight experiments supported the Agency's goal of dramatically reducing the cost of access to space and defined the future of space transportation pushing technology into a new era of space development and exploration at the dawn of the new century. The X-34 program was cancelled in 2001.

Pathfinder aircraft flight #1

NASA Image and Video Library

1996-11-19

The Pathfinder solar-powered research aircraft is silhouetted against a clear blue sky as it soars aloft during a checkout flight from the Dryden Flight Research Center, Edwards, California, November, 1996.

MARS PATHFINDER CAMERA TEST IN SAEF-2

NASA Technical Reports Server (NTRS)

1996-01-01

In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), workers from the Jet Propulsion Laboratory (JPL) are conducting a systems test of the imager for the Mars Pathfinder. The imager (white and metallic cylindrical element close to hand of worker at left) is a specially designed camera featuring a stereo- imaging system with color capability provided by a set of selectable filters. It is mounted atop an extendable mast on the Pathfinder lander. Visible to the far left is the small rover which will be deployed from the lander to explore the Martian surface. Transmitting back to Earth images of the trail left by the rover will be one of the mission objectives for the imager. To the left of the worker standing near the imager is the mast for the low-gain antenna; the round high-gain antenna is to the right. Visible in the background is the cruise stage that will carry the Pathfinder on a direct trajectory to Mars. The Mars Pathfinder is one of two Mars-bound spacecraft slated for launch aboard Delta II expendable launch vehicles this year.

Free-Flight Experiments in LISA Pathfinder

NASA Technical Reports Server (NTRS)

Thorpe, J. I.; Cutler, C. J.; Hewitson, M.; Jennrich, O.; Maghami, P.; Paczkowski, S.; Russano, G.; Vitale, S.; Weber, W. J.

2014-01-01

The LISA Pathfinder mission will demonstrate the technology of drag-free test masses for use as inertial references in future space-based gravitational wave detectors. To accomplish this, the Pathfinder spacecraft will perform drag-free flight about a test mass while measuring the acceleration of this primary test mass relative to a second reference test mass. Because the reference test mass is contained within the same spacecraft, it is necessary to apply forces on it to maintain its position and attitude relative to the spacecraft. These forces are a potential source of acceleration noise in the LISA Pathfinder system that are not present in the full LISA configuration. While LISA Pathfinder has been designed to meet it's primary mission requirements in the presence of this noise, recent estimates suggest that the on-orbit performance may be limited by this 'suspension noise'. The drift-mode or free-flight experiments provide an opportunity to mitigate this noise source and further characterize the underlying disturbances that are of interest to the designers of LISA-like instruments. This article provides a high-level overview of these experiments and the methods under development to analyze the resulting data.

Preliminary Findings of the Photovoltaic Cell Calibration Experiment on Pathfinder Flight 95-3

NASA Technical Reports Server (NTRS)

Vargas-Aburto, Carlos

1997-01-01

The objective of the photovoltaic (PV) cell calibration experiment for Pathfinder was to develop an experiment compatible with an ultralight UAV to predict the performance of PV cells at AM0, the solar spectrum in space, using the Langley plot technique. The Langley plot is a valuable technique for this purpose and requires accurate measurements of air mass (pressure), cell temperature, solar irradiance, and current-voltage(IV) characteristics with the cells directed normal to the direct ray of the sun. Pathfinder's mission objective (95-3) of 65,000 ft. maximum altitude, is ideal for performing the Langley plot measurements. Miniaturization of electronic data acquisition equipment enabled the design and construction of an accurate and light weight measurement system that meets Pathfinder's low payload weight requirements.

CSTI high capacity power. [Civil Space Technology Initiative

NASA Technical Reports Server (NTRS)

Winter, Jerry M.

1989-01-01

In FY-88, the Advanced Technology Program was incorporated into NASA's Civil Space Technology Initiative (CSTI). The CSTI Program was established to provide the foundation for technology development in automation and robotics, information, propulsion, and power. The CSTI High Capacity Power Program builds on the technology efforts of the SP-100 program, incorporates the previous NASA SP-100 Advanced Technology project, and provides a bridge to NASA Project Pathfinder. The elements of CSTI High Capacity Power development include Converrsion Systems, Thermal Management, Power Management, System Diagnostics, and Environmental Interactions. Technology advancement in all areas, including materials, is required to assure the high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems.

Mars Pathfinder Landing Site and Surroundings

NASA Technical Reports Server (NTRS)

2007-01-01

NASA's Mars Pathfinder landed on Mars on July 4, 1997, and continued operating until Sept. 27 of that year. The landing site is on an ancient flood plain of the Ares and Tiu outflow channels. The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter took an image on Dec. 21, 2006, that provides unprecedented detail of the geology of the region and hardware on the surface.

[figure removed for brevity, see original site] HiRISE Image This is the entire image. The crater at center bottom was unofficially named 'Big Crater' by the Pathfinder team. Its wall was visible from Pathfinder, located 3 kilometers (2 miles) to the north. The two bright features to the upper left of Big Crater are the 'Twin Peaks,' also observed by Pathfinder. The bright mound to the upper right of the Twin Peaks is 'North Knob,' seen in Pathfinder images as peaking over the horizon.

At this scale there is no obvious geologic evidence of an ancient flood. Rather, impact craters dominate the scene, attesting to an old surface. The age is probably on the order of 1.8 billion to 3.5 billion years, when the Ares and Tiu floods are estimated to have occurred. Wind-formed linear ripples and dunes are seen throughout and are concentrated within craters. Sets of polygonal ridges of enigmatic origin are seen east of the Pathfinder lander. Rocks are visible over the entire image, with heavy concentrations near fresh-looking craters. Most of them are probably blocks tossed outward by crater-forming impacts.

The complete image is centered at 19.1 degrees north latitude, 326.8 degrees east longitude. The range to the target site was 284.7 kilometers (177.9 miles). At this distance the image scale is 28.5 centimeters (11 inches) per pixel, so objects about 85 centimeters (33 inches) across are resolved. The image shown here has been map-projected to 25 centimeters (10 inches) per pixel. North is up. The image was taken at a local Mars time of 3:35 p.m., and the scene is illuminated from the west with a solar incidence angle of 52 degrees, thus the sun was about 38 degrees above the horizon. At a solar longitude of 154.0 degrees, the season on Mars is northern summer.

[figure removed for brevity, see original site] Landing Site Region This is a close-up of the area in the vicinity of the Pathfinder landing site. Major features are named. The white box outlines the area of the image, discussed next, where hardware is seen.

[figure removed for brevity, see original site] Hardware on the Surface This image shows the Pathfinder lander on the surface. Zooming in, one can discern the ramps, science deck, and portions of the airbags on the Pathfinder lander. (See next image for closer view.) The back shell and parachute are to the south, and four features that may be portions of the heat shield are identified. Two of these were visible from Pathfinder. At the time of that mission, the nearest object was provisionally identified as the back shell. However, analysis of the HiRISE image and reinterpretation of Pathfinder images, plus an improved understanding of how hardware looks on the Martian surface based on ground-level and orbital images of the Mars Exploration Rover landing sites, indicate that the glint is bright enough that it may be insulating material from inside the heat shield. The back shell and parachute were out of sight behind a ridge from Pathfinder's ground view. One of the three bright features, identified as heat shield debris, was also identified during the Pathfinder mission.

[figure removed for brevity, see original site] [figure removed for brevity, see original site] Annotated Version Unannotated Version Topographic Map of Landing Site Region Portions of the HiRISE image are overlaid onto color-coded topographic maps constructed by the U.S. Geological Survey from stereo images acquired by the Imager for Mars Pathfinder on the lander. The white feature at the center is Pathfinder lander. The scales on the x and y axes are in meters, with the lander as the zero point. The color code for elevation relative to the lander is different in the left and right images, and shown in meters underneath each image. The correspondence between the overhead view revealed by HiRISE and the positions of topographic features inferred almost a decade ago from Pathfinder's horizontal view of the landscape is striking. The close-up on the right complements panoramas taken by the lander's camera, including the accompanying composite version showing the Sojourner rover at various locations it reached during the mission.

[figure removed for brevity, see original site] Mars Pathfinder Gallery Panorama This version of the Gallery Panorama taken with the lander's Imager for Mars Pathfinder camera shows many of the locations where the mission's Sojourner rover ended a Martian day during the 12-week mission. (There was only one Sojourner. The image is a composite.) One annotation indicates the last known position of Sojourner, near the rock 'Chimp,' at the time of the final data transmission from the lander. The location labeled 'Sojourner?' has been tentatively identified as the current position of the rover based on comparison of the ground-level view with the Dec. 21, 2006, image from NASA's Mars Reconnaissance Orbiter. At the proposed current location of the rover, a feature can be discerned in the 2006 orbital image that is about the right size for Sojourner and wasn't present when the Gallery Panorama was taken. Some rocks and other features that can be identified in the orbiter's high-resolution view are labeled in this ground-level view.

[figure removed for brevity, see original site] Topographic Perspective of Landing Site Region) This is a perspective view based on the topographic map and artificial color derived from Pathfinder and other data. The vertical scale is exaggerated by a factor of three, compared with horizontal dimensions. The white feature at center is the Pathfinder lander. It appears flat because the topographic map derived from the Imager for Mars Pathfinder data did not include the spacecraft itself.

MARS PATHFINDER LANDER REMOVED FROM SHIPPING CONTAINER IN SAEF-2

NASA Technical Reports Server (NTRS)

1996-01-01

In the SAEF-2 spacecraft checkout facility at Kennedy Space Center, engineers and technicians from Jet Propulsion Laboratory remove the Mars Pathfinder lander from its shipping container, still covered in protective wrapping. Pictured from L-R, Linda Robeck, Jerry Gutierrez, Lorraine Garcia, Chuck Foehlinger of JPL. The arrival of the spacecraft at KSC from Pasadena, CA occurred on Aug. 13, 1996. Launch of Mars Pathfinder aboard a McDonnell Douglas Delta II rocket will occur from Pad B at Complex 17 on Dec. 2.

Mars Pathfinder Microrover- Implementing a Low Cost Planetary Mission Experiment

NASA Technical Reports Server (NTRS)

Matijevic, J.

1996-01-01

The Mars Pathfinder Microrover Flight Experiment (MFEX) is a NASA Office of Space Access and Technology (OSAT) flight experiment which has been delivered and integrated with the Mars Pathfinder (MPF) lander and spacecraft system. The total cost of the MFEX mission, including all subsystem design and development, test, integration with the MPF lander and operations on Mars has been capped at $25 M??is paper discusses the process and the implementation scheme which has resulted in the development of this first Mars rover.

MARS PATHFINDER AIR BAG INSTALLATION IN SAEF-2

NASA Technical Reports Server (NTRS)

1996-01-01

In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), the Jet Propulsion Laboratory (JPL) team installs air bags on the Mars Pathfinder lander. The four airbags will cushion the lander as it touches down on the Martian surface, protecting the delicate instruments and Surveyor small rover inside the tetrahedral-shaped lander. The Mars Pathfinder is one of two Mars-bound spacecraft being prepared for launch this fall. Liftoff is set for Dec. 2 at the beginning of a 24-day launch period.

False Color Processing to Enhance Differences Around Yogi

NASA Technical Reports Server (NTRS)

1997-01-01

In this scene showing the rover deployed at rock Yogi, the colors have similarly been enhanced to bring out differences. The same three kinds of rocks are recognized as in the distance. Yogi (red arrow), one of the large rocks with a weathered coating, exhibits a fresh face to the northeast, resulting perhaps from eolian scouring or from fracturing off of pieces to expose a fresher surface. Barnacle Bill and Cradle (blue arrows) are typical of the unweathered smaller rocks. During its traverse to Yogi the rover stirred the soil and exposed material from several cm in depth. During one of the turns to deploy Sojourner's Alpha Proton X-Ray Spectrometer (inset and white arrow), the wheels dug particularly deeply and exposed white material. Spectra of this white material show it is virtually identical to Scooby Doo, and such white material may underlie much of the site. The lander's rear ramp, which Sojourner used to descend to the Martian surface, is at lower left.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and managed the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

Overhead View of Pathfinder Landing Site

NASA Technical Reports Server (NTRS)

1997-01-01

Planimetric (overhead view) map of the landing site, to a distance of 20 meters from the spacecraft. North is at the top in this and Plates 3-5. To produce this map, images were geometrically projected onto an assumed mean surface representing the ground. Features above the ground plane (primarily rocks) therefore appear displaced radially outward; the amount of distortion increases systematically with distance. The upper surfaces of the lander and rover also appear enlarged and displaced because of their height. Primary grid (white) is based on the Landing Site Cartographic (LSC) coordinate system, defined with X eastward, Y north, and Z up, and origin located at the mean ground surface immediately beneath the deployed position of the IMP camera gimbal center. Secondary ticks (cyan) are based on the Mars local level (LL) frame, which has X north, Y east, Z down, with origin in the center of the lander baseplate. Rover positions (including APXS measurements) are commonly reported in the LL frame. Yellow grid shows polar coordinates based on the LSC system. Cartographic image processing by U.S. Geological Survey.

NOTE: original caption as published in Science Magazine

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Science Programs for a 2-m Class Telescope at Dome C, Antarctica: PILOT, the Pathfinder for an International Large Optical Telescope

NASA Astrophysics Data System (ADS)

Burton, M. G.; Lawrence, J. S.; Ashley, M. C. B.; Bailey, J. A.; Blake, C.; Bedding, T. R.; Bland-Hawthorn, J.; Bond, I. A.; Glazebrook, K.; Hidas, M. G.; Lewis, G.; Longmore, S. N.; Maddison, S. T.; Mattila, S.; Minier, V.; Ryder, S. D.; Sharp, R.; Smith, C. H.; Storey, J. W. V.; Tinney, C. G.; Tuthill, P.; Walsh, A. J.; Walsh, W.; Whiting, M.; Wong, T.; Woods, D.; Yock, P. C. M.

2005-08-01

The cold, dry, and stable air above the summits of the Antarctic plateau provides the best ground-based observing conditions from optical to sub-millimetre wavelengths to be found on the Earth. Pathfinder for an International Large Optical Telescope (PILOT) is a proposed 2m telescope, to be built at Dome C in Antarctica, able to exploit these conditions for conducting astronomy at optical and infrared wavelengths. While PILOT is intended as a pathfinder towards the construction of future grand-design facilities, it will also be able to undertake a range of fundamental science investigations in its own right. This paper provides the performance specifications for PILOT, including its instrumentation. It then describes the kinds of projects that it could best conduct. These range from planetary science to the search for other solar systems, from star formation within the Galaxy to the star formation history of the Universe, and from gravitational lensing caused by exo-planets to that produced by the cosmic web of dark matter. PILOT would be particularly powerful for wide-field imaging at infrared wavelengths, achieving near diffraction-limited performance with simple tip-tilt wavefront correction. PILOT would also be capable of near diffraction-limited performance in the optical wavebands, as well be able to open new wavebands for regular ground-based observation, in the mid-IR from 17 to 40μm and in the sub-millimetre at 200μm.

The Earth System Science Pathfinder Orbiting Carbon Observatory (OCO) Mission

NASA Technical Reports Server (NTRS)

Crisp, David

2003-01-01

A viewgraph presentation describing the Earth System Science Pathfinder Orbiting Carbon Observatory (OCO) Mission is shown. The contents include: 1) Why CO2?; 2) What Processes Control CO2 Sinks?; 3) OCO Science Team; 4) Space-Based Measurements of CO2; 5) Driving Requirement: Precise, Bias-Free Global Measurements; 6) Making Precise CO2 Measurements from Space; 7) OCO Spatial Sampling Strategy; 8) OCO Observing Modes; 9) Implementation Approach; 10) The OCO Instrument; 11) The OCO Spacecraft; 12) OCO Will Fly in the A-Train; 13) Validation Program Ensures Accuracy and Minimizes Spatially Coherent Biases; 14) Can OCO Provide the Required Precision?; 15) O2 Column Retrievals with Ground-based FTS; 16) X(sub CO2) Retrieval Simulations; 17) Impact of Albedo and Aerosol Uncertainty on X(sub CO2) Retrievals; 18) Carbon Cycle Modeling Studies: Seasonal Cycle; 19) Carbon Cycle Modeling Studies: The North-South Gradient in CO2; 20) Carbon Cycle Modeling Studies: Effect of Diurnal Biases; 21) Project Status and Schedule; and 22) Summary.

Ballistic Range Testing of the Mars Exploration Rover Entry Capsule

NASA Technical Reports Server (NTRS)

Schoenenberger, Mark; Hathaway, Wayne; Yates, Leslie; Desai, Prasun

2005-01-01

Results from a 25 shot ballistic range test of the Mars Exploration Rover (MER) aeroshell are presented. The supersonic pitch damping properties of the MER capsule were characterized between Mach = 1.5 and Mach = 3.5 and total angles-of-attack from 0 degrees to greater than 25 degrees. Three capsule center-of-gravity positions were tested across this range of conditions, 0.27, 0.30 and 0.33 body diameters aft of the nose. Parameter identification results show that the capsule is dynamically unstable at low angles-of-attack across the Mach numbers tested, with instability increasing with lower speeds. This dynamic instability was seen to increase with aft center-of-gravity movement. The MER outer mold line was very similar to the successful Mars Pathfinder capsule with only minor modifications. Pathfinder relied on Viking forced oscillation data for preflight predictions. The pitch damping data calculated from this test program are shown to more accurately reproduce the measured Path finder flight data.

Immersive Environments for Mission Operations: Beyond Mars Pathfinder

NASA Technical Reports Server (NTRS)

Wright, J.; Hartman, F.; Cooper, B.

1998-01-01

Immersive environments are just beginning to be used to support mission operations at the Jet Propulsion Laboratory. This technology contributed to the Mars Pathfinder Mission in planning sorties for the Sojourner rover.

Photogrammetric analysis of horizon panoramas: The Pathfinder landing site in Viking orbiter images

USGS Publications Warehouse

Oberst, J.; Jaumann, R.; Zeitler, W.; Hauber, E.; Kuschel, M.; Parker, T.; Golombek, M.; Malin, M.; Soderblom, L.

1999-01-01

Tiepoint measurements, block adjustment techniques, and sunrise/sunset pictures were used to obtain precise pointing data with respect to north for a set of 33 IMP horizon images. Azimuth angles for five prominent topographic features seen at the horizon were measured and correlated with locations of these features in Viking orbiter images. Based on this analysis, the Pathfinder line/sample coordinates in two raw Viking images were determined with approximate errors of 1 pixel, or 40 m. Identification of the Pathfinder location in orbit imagery yields geological context for surface studies of the landing site. Furthermore, the precise determination of coordinates in images together with the known planet-fixed coordinates of the lander make the Pathfinder landing site the most important anchor point in current control point networks of Mars. Copyright 1999 by the American Geophysical Union.

Yogi the rock

NASA Technical Reports Server (NTRS)

1997-01-01

Yogi, a rock taller than rover Sojourner, is the subject of this image, taken by the deployed Imager for Mars Pathfinder (IMP) on Sol 3. The soil in the foreground will be the location of multiple soil mechanics experiments performed by Sojourner's cleated wheels. Pathfinder scientists will be able to control the force inflicted on the soil beneath the rover's wheels, giving them insight into the soil's mechanical properties.

The image was taken by the Imager for Mars Pathfinder (IMP) after its deployment on Sol 3. Mars Pathfinder was developed and managed by the Jet Propulsion Laboratory (JPL) for the National Aeronautics and Space Administration. JPL is an operating division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

IT Labs Proof-of-Concept Project: Technical Data Interoperability (TDI) Pathfinder Via Emerging Standards

NASA Technical Reports Server (NTRS)

Conroy, Mike; Gill, Paul; Ingalls, John; Bengtsson, Kjell

2014-01-01

No known system is in place to allow NASA technical data interoperability throughout the whole life cycle. Life Cycle Cost (LCC) will be higher on many developing programs if action isn't taken soon to join disparate systems efficiently. Disparate technical data also increases safety risks from poorly integrated elements. NASA requires interoperability and industry standards, but breaking legacy ways is a challenge.

Air Force Research Laboratory Success Stories: A Review of 1997/1998

DTIC Science & Technology

1999-03-01

one year). Assuming that 60 percent of the electrical power required for these sites could be generated with solar cells , the higher efficiency AMTEC ...engineers ability to meet the cost goal of the Mars Pathfinder program. Accomplishment High efficiency solar cells and non-rechargeable batteries developed...integrated manufacturing system to efficiently mix low volume and high volume processing. MPCL metrics have been defined in categories which reflect

Pathfinder

NASA Image and Video Library

2004-04-15

This is an artist's concept of the X-34 reusable technology testbed vehicle that was designed to demonstrate technologies that were essential to lowering the cost of access to space. Powered by a LOX and RP-1 liquid Fastrac engine that was designed and built by the Marshall Space Flight Center, the X-34 was capable of speeds up to Mach 8 and altitudes of 250,000-feet. The X-34 program was cancelled in 2001.

Review of NASA's Planned Mars Program

NASA Technical Reports Server (NTRS)

1996-01-01

The exploration of Mars has long been a prime scientific objective of the U.S. planetary exploration program. Yet no U.S. spacecraft has successfully made measurements at Mars since the Viking missions of the late 1970s. Mars Observer, which was designed to conduct global observations from orbit, failed just before orbit insertion in 1993. The Russian spacecraft Phobos 2 did succeed in making some observations of the planet in 1989, but it was designed primarily to observe Phobos, the innermost satellite of Mars; the spacecraft failed 2 months after insertion into Mars orbit during the complex maneuvers required to rendezvous with the martian satellite. In fall 1996 NASA plans to launch Mars Pathfinder for a landing on the martian surface in mid-1997. This spacecraft is one of the first two missions in NASA's Discovery program that inaugurates a new style of planetary exploration in which missions are low-cost (less than $150 million) and have very focused science objectives. As can be seen in the comparative data presented in Box 1, this mission is considerably smaller in terms of cost, mass, and scope than NASA's previous Mars missions. NASA's FY 1995 budget initiated a continuing Mars exploration program, called Mars Surveyor, that involves multiple launches of spacecraft as small as or smaller than Mars Pathfinder to Mars over the next several launch opportunities, which recur roughly every 26 months. The first mission in the program, Mars Global Surveyor, set for launch late in 1996, is intended to accomplish many of the objectives of the failed Mars Observer. Like the Discovery program, Mars Surveyor is a continuing series of low-cost missions, each of which has highly focused science objectives. See Box 1 for comparative details of those Surveyor missions currently defined. Around the same time that the Mars Surveyor series was chosen as the centerpiece of NASA's solar system exploration program, the Committee on Planetary and Lunar Exploration (COMPLEX) designated Mars as one of four scientific targets for emphasis in future studies. It was against this background that the Space Studies Board charged COMPLEX to review whether the Mars Pathfinder and Surveyor programs, as presently conceived, satisfy the highest priorities for understanding Mars as provided in its report, An Integrated Strategy for the Planetary Sciences: 1995-2010. The present document is COMPLEX's assessment of the scientific potential of NASA's new approach to Mars exploration. This assessment considers how well the scientific objectives of the Mars Surveyor program match those of the Integrated Strategy; it also addresses some advantages and disadvantages of the smaller-faster-cheaper approach to the exploration of Mars. The capabilities of the various instruments are not discussed in detail since the Mars Observer instruments, all of which are scheduled for reflight, have already been assessed by COMPLEX2 and later instruments are, in general, not yet well defined.

Mineralogic and compositional properties of Martian soil and dust: results from Mars Pathfinder

USGS Publications Warehouse

Bell, J.F.; McSween, H.Y.; Crisp, J.A.; Morris, R.V.; Murchie, S.L.; Bridges, N.T.; Johnson, J. R.; Britt, D.T.; Golombek, M.P.; Moore, H.J.; Ghosh, A.; Bishop, J.L.; Anderson, R.C.; Brückner, J.; Economou, T.; Greenwood, J.P.; Gunnlaugsson, H.P.; Hargraves, R.M.; Hviid, S.; Knudsen, J.M.; Madsen, M.B.; Reid, R.; Rieder, R.; Soderblom, L.

2000-01-01

Mars Pathfinder obtained multispectral, elemental, magnetic, and physical measurements of soil and dust at the Sagan Memorial Station during the course of its 83 sol mission. We describe initial results from these measurements, concentrating on multispectral and elemental data, and use these data, along with previous Viking, SNC meteorite, and telescopic results, to help constrain the origin and evolution of Martian soil and dust. We find that soils and dust can be divided into at least eight distinct spectral units, based on parameterization of Imager for Mars Pathfinder (IMP) 400 to 1000 nm multispectral images. The most distinctive spectral parameters for soils and dust are the reflectivity in the red, the red/blue reflectivity ratio, the near-IR spectral slope, and the strength of the 800 to 1000 nm absorption feature. Most of the Pathfinder spectra are consistent with the presence of poorly crystalline or nanophase ferric oxide(s), sometimes mixed with small but varying degrees of well-crystalline ferric and ferrous phases. Darker soil units appear to be coarser-grained, compacted, and/or mixed with a larger amount of dark ferrous materials relative to bright soils. Nanophase goethite, akaganeite, schwertmannite, and maghemite are leading candidates for the origin of the absorption centered near 900 nm in IMP spectra. The ferrous component in the soil cannot be well-constrained based on IMP data. Alpha proton X-ray spectrometer (APXS) measurements of six soil units show little variability within the landing site and show remarkable overall similarity to the average Viking-derived soil elemental composition. Differences exist between Viking and Pathfinder soils, however, including significantly higher S and Cl abundances and lower Si abundances in Viking soils and the lack of a correlation between Ti and Fe in Pathfinder soils. No significant linear correlations were observed between IMP spectral properties and APXS elemental chemistry. Attempts at constraining the mineralogy of soils and dust using normative calculations involving mixtures of smectites and silicate and oxide minerals did not yield physically acceptable solutions. We attempted to use the Pathfinder results to constrain a number of putative soil and dust formation scenarios, including palagonitization and acid-fog weathering. While the Pathfinder soils cannot be chemically linked to the Pathfinder rocks by palagonitization, this study and McSween et al. [1999] suggest that palagonitic alteration of a Martian basaltic rock, plus mixture with a minor component of locally derived andesitic rock fragments, could be consistent with the observed soil APXS and IMP properties.

Operations and Autonomy of the Mars Pathfinder Microrover

NASA Technical Reports Server (NTRS)

Mishkin, A. H.; Morrison, J. C.; Nguyen, T. T.; Stone, H. W.; Cooper, B. K.

1998-01-01

The Microrover Flight Experiment (MFEX) is a NSAS OACT (Office of Advanced Concepts and Technology) flight experiment which, integrated with the Mars Pathfinder (MPF) lander and spacecraft system, landed on Mars on July 4, 1997.

Lithium-Thionyl Chloride Batteries for the Mars Pathfinder Microrover

NASA Technical Reports Server (NTRS)

Deligiannis, Frank; Frank, Harvey; Staniewicz, R. J.; Willson, John

1996-01-01

A discussion of the power requirements for the Mars Pathfinder Mission is given. Topics include: battery requirements; cell design; battery design; test descriptions and results. A summary of the results is also included.

Pathfinder on lakebed rolling out for test flight

NASA Image and Video Library

1995-12-10

The Pathfinder research aircraft's wing structure is clearly defined in this photo as personnel from AeroVironment rolled it out onto the lakebed at NASA's Dryden Flight Research Center, Edwards, California, for another test flight.

Processing and Analysis of Mars Pathfinder Science Data at JPL's Science Data Processing Section

NASA Technical Reports Server (NTRS)

LaVoie, S.; Green, W.; Runkle, A.; Alexander, D.; Andres, P.; DeJong, E.; Duxbury, E.; Freda, D.; Gorjian, Z.; Hall, J.;

Sojourner Sits Near "Rock Garden"

NASA Image and Video Library

2003-02-01

The Mars Pathfinder Rover Sojourner images by the Imager for Mars Pathfinder as it nears the rock "Wedge." Part of the Rock Garden is visible in the upper right of the image. http://photojournal.jpl.nasa.gov/catalog/PIA04318

Analysis of Mars Pathfinder Entry Data, Aerothermal Heating, and Heat Shield Material Response

NASA Technical Reports Server (NTRS)

Milos, Frank; Chen, Y. K.; Tran, H. K.; Rasky, Daniel J. (Technical Monitor)

1997-01-01

The Mars Pathfinder heatshield contained several thermocouples and resistance thermometers. A description of the experiment, the entry data, and analysis of the entry environment and material response is presented. In particular, the analysis addresses uncertainties of the data and the fluid dynamics and material response models. The calculations use the latest trajectory and atmosphere reconstructions for the Pathfinder entry. A modified version of the GIANTS code is used for CFD (computational fluid dynamics) analyses, and FIAT is used for material response. The material response and flowfield are coupled appropriately. Three different material response models are considered. The analysis of Pathfinder entry data for validation of aerothermal heating and material response models is complicated by model uncertainties and unanticipated data-acquisition and processing problems. We will discuss these issues as well as ramifications of the data and analysis for future Mars missions.

Addressing Dynamic Issues of Program Model Checking

NASA Technical Reports Server (NTRS)

Lerda, Flavio; Visser, Willem

2001-01-01

Model checking real programs has recently become an active research area. Programs however exhibit two characteristics that make model checking difficult: the complexity of their state and the dynamic nature of many programs. Here we address both these issues within the context of the Java PathFinder (JPF) model checker. Firstly, we will show how the state of a Java program can be encoded efficiently and how this encoding can be exploited to improve model checking. Next we show how to use symmetry reductions to alleviate some of the problems introduced by the dynamic nature of Java programs. Lastly, we show how distributed model checking of a dynamic program can be achieved, and furthermore, how dynamic partitions of the state space can improve model checking. We support all our findings with results from applying these techniques within the JPF model checker.

Interactions of UNC-34 Enabled With Rac GTPases and the NIK Kinase MIG-15 in Caenorhabditis elegans Axon Pathfinding and Neuronal Migration

PubMed Central

Shakir, M. Afaq; Gill, Jason S.; Lundquist, Erik A.

2006-01-01

Many genes that affect axon pathfinding and cell migration have been identified. Mechanisms by which these genes and the molecules they encode interact with one another in pathways and networks to control developmental events are unclear. Rac GTPases, the cytoskeletal signaling molecule Enabled, and NIK kinase have all been implicated in regulating axon pathfinding and cell migration. Here we present evidence that, in Caenorhabditis elegans, three Rac GTPases, CED-10, RAC-2, and MIG-2, define three redundant pathways that each control axon pathfinding, and that the NIK kinase MIG-15 acts in each Rac pathway. Furthermore, we show that the Enabled molecule UNC-34 defines a fourth partially redundant pathway that acts in parallel to Rac/MIG-15 signaling in axon pathfinding. Enabled and the three Racs also act redundantly to mediate AQR and PQR neuronal cell migration. The Racs and UNC-34 Ena might all control the formation of actin-based protrusive structures (lamellipodia and filopodia) that mediate growth cone outgrowth and cell migration. MIG-15 does not act with the three Racs in execution of cell migration. Rather, MIG-15 affects direction of PQR neuronal migration, similar to UNC-40 and DPY-19, which control initial Q cell polarity, and Wnt signaling, which acts later to control Q cell-directed migration. MIG-2 Rac, which acts with CED-10 Rac, RAC-2 Rac, and UNC-34 Ena in axon pathfinding and cell migration, also acts with MIG-15 in PQR directional migration. PMID:16204220

Disturbance Reduction System Thrusters Stabilize LISA Pathfinder

NASA Image and Video Library

2015-12-03

The LISA Pathfinder spacecraft is on its way to space, having successfully launched from Kourou, French Guiana Dec. 3, 2015. On board is the state-of-the-art Disturbance Reduction System DRS, a thruster technology developed at NASA JPL.

Dark Energy and Gravity Experiment Explorer and Pathfinder

NASA Astrophysics Data System (ADS)

Chiow, S.-w.; Yu, N.

2018-02-01

We propose to utilize the unique gravity and vacuum environment in the orbits of the Deep Space Gateway for direct detections of dark energy using atom interferometers, and for pathfinder experiments for future gravitational wave and dark matter detections.

Pathfinder

NASA Image and Video Library

2004-04-15

Pictured is an artist's concept of the X-37 Demonstrator re-entry. After being launched from the cargo bay of a Shuttle as a secondary payload, the X-37 remains on-orbit up to 21 days performing a variety of experiments before re-entering the Earth's atmosphere and landing. These vehicles supported the Agency's goal of dramatically reducing the cost of access to space in attempt to define the future of space transportation. The X-37 program was discontinued in 2003.

Pathfinder

NASA Image and Video Library

2004-04-15

This is an artist's concept of the X-34 Demonstrator, a reusable technology testbed vehicle that was designed to demonstrate technologies that were essential to lowering the cost of access to space. Powered by a LOX and RP-1 liquid Fastrac engine that was designed and built by the Marshall Space Flight Center, the X-34 would be capable of speeds up to Mach 8 and altitudes of 250,000-feet. The X-34 program was cancelled in 2001.

Pathfinder

NASA Image and Video Library

2004-04-15

This is an artist's concept of the X-34 reusable technology testbed demonstrator on-orbit. The X-34 was designed to demonstrate technologies that are essential to lowering the cost of access to space. Powered by a LOX and RP-1 liquid Fastrac engine designed and built by the Marshall Space Flight Center, the X-34 would be capable of speeds up to Mach 8 and altitudes of 250,000-feet. The X-34 program was cancelled in 2001.

NAS technical summaries. Numerical aerodynamic simulation program, March 1992 - February 1993

NASA Technical Reports Server (NTRS)

1994-01-01

NASA created the Numerical Aerodynamic Simulation (NAS) Program in 1987 to focus resources on solving critical problems in aeroscience and related disciplines by utilizing the power of the most advanced supercomputers available. The NAS Program provides scientists with the necessary computing power to solve today's most demanding computational fluid dynamics problems and serves as a pathfinder in integrating leading-edge supercomputing technologies, thus benefitting other supercomputer centers in government and industry. The 1992-93 operational year concluded with 399 high-speed processor projects and 91 parallel projects representing NASA, the Department of Defense, other government agencies, private industry, and universities. This document provides a glimpse at some of the significant scientific results for the year.

From the Northern Eurasia Earth Science Partnership Initiative (NEESPI) towards the Northern Eurasia Future Initiative (NEFI)

NASA Astrophysics Data System (ADS)

Groisman, Pavel; Gutman, Garik; Gulev, Sergey; Maksyutov, Shamil

2015-04-01

Northern Eurasia Earth Science Partnership Initiative (NEESPI, http://neespi.org) was launched in 2004. With its multidisciplinary focus, the internationally funded NEESPI (more than 170 individual international projects during the past decade) has challenged participants to research climate-ecosystem interactions, societal impacts from extreme events in Northern Eurasia, and the feedbacks of these interactions and impacts to the global Earth system. NEESPI was endorsed by major ESSP Programs and Projects and the cornerstone support for the NEESPI studies was provided by the NASA Land Cover and Land Use Change Program and the Russian Academy of Sciences. Now it is the time to synthesis the main achievements of the NEESPI researchers and to re-assess its Science Questions and Objectives of the regional research within the new Future Earth Program paradigm with the focus on interdisciplinary solution-oriented approach that will allow effective policy-making in environment management and control. At the sequence of Workshops (the last of them will be in Prague one week prior to this Assembly) we formulated a major Science Question of the new Northern Eurasia Future Initiative (NEFI): "What will the changes in the regional ecosystems dynamics and interactions mean for the societal well-being, activities, health, and strategic planning in Northern Eurasia?" The major NEFI challenge will be the services aimed on providing in Northern Eurasia a sustainable societal development in changing climate, ecosystems, and societies. At this presentation we shall brief the audience about the main results of the NEESPI researchers, and lay down the plans for the future NEFI studies. At the side event of the Meeting, we shall initiate preparation of the book which will synthesize major NEESPI achievements.

Modis, SeaWIFS, and Pathfinder funded activities

NASA Technical Reports Server (NTRS)

Evans, Robert H.

1995-01-01

MODIS (Moderate Resolution Imaging Spectrometer), SeaWIFS (Sea-viewing Wide Field Sensor), Pathfinder, and DSP (Digital Signal Processor) objectives are summarized. An overview of current progress is given for the automatic processing database, client/server status, matchup database, and DSP support.

"Roadrunner Flats"

NASA Image and Video Library

1997-10-14

This enhanced color image of the Pathfinder landing site shows the eastern horizon. The elongated, reddish, low contrast region in the distance is "Roadrunner Flats." This image was taken by the Imager for Mars Pathfinder (IMP). Sojourner spent 83 days of a planned seven-day mission exploring the Martian terrain, acquiring images, and taking chemical, atmospheric and other measurements. The final data transmission received from Pathfinder was at 10:23 UTC on September 27, 1997. Although mission managers tried to restore full communications during the following five months, the successful mission was terminated on March 10, 1998. http://photojournal.jpl.nasa.gov/catalog/PIA00979

Strategy for selecting Mars Pathfinder landing sites

NASA Technical Reports Server (NTRS)

Greeley, Ronald; Kuzmin, Ruslin O.

1994-01-01

A strategy for Pathfinder site selection must be developed that is fundamentally different from most previous considerations. At least two approaches can be identified. In one approach, the objective is to select a site representing a key geologic unit on Mars, i.e., a unit that is widespread, easily recognized, and used frequently as a datum in various investigations. The second approach is to select a site that potentially affords access to a wide variety of rock types. Because rover range is limited, rocks from a variety of sources must be assembled in a small area for sampling. Regardless of the approach taken in site selection, the Pathfinder site should include eolian deposits and provisions should be made to obtain measurements on soils. A recommended approach for selecting the Mars Pathfinder landing site is to identify a deltaic deposit, composed of sediments derived from sources of various ages and geologic units that shows evidence of eolian activity. The site should be located as close as possible to the part of the outwash where rapid deposition occurred because the likelihood of 'sorting' by size and composition increases with distance, decreasing the probability of heterogeneity. In addition, it is recommended that field operation tests be conducted to gain experience and insight into conducting science with Pathfinder.

Maps of the Martian Landing Sites and Rover Traverses: Viking 1 and 2, Mars Pathfinder, and Phoenix Landers, and the Mars Exploration Rovers.

NASA Astrophysics Data System (ADS)

Parker, T. J.; Calef, F. J., III; Deen, R. G.; Gengl, H.

2016-12-01

The traverse maps produced tactically for the MER and MSL rover missions are the first step in placing the observations made by each vehicle into a local and regional geologic context. For the MER, Phoenix and MSL missions, 25cm/pixel HiRISE data is available for accurately localizing the vehicles. Viking and Mars Pathfinder, however, relied on Viking Orbiter images of several tens of m/pixel to triangulate to horizon features visible both from the ground and from orbit. After Pathfinder, MGS MOC images became available for these landing sites, enabling much better correlations to horizon features and localization predictions to be made, that were then corroborated with HiRISE images beginning 9 years ago. By combining topography data from MGS, Mars Express, and stereo processing of MRO CTX and HiRISE images into orthomosaics (ORRs) and digital elevation models (DEMs), it is possible to localize all the landers and rover positions to an accuracy of a few tens of meters with respect to the Mars global control net, and to better than half a meter with respect to other features within a HiRISE orthomosaic. JPL's MIPL produces point clouds of the MER Navcam stereo images that can be processed into 1cm/pixel ORR/DEMs that are then georeferenced to a HiRISE/CTX base map and DEM. This allows compilation of seamless mosaics of the lander and rover camera-based ORR/DEMs with the HiRISE ORR/DEM that can be viewed in 3 dimensions with GIS programs with that capability. We are re-processing the Viking Lander, Mars Pathfinder, and Phoenix lander data to allow similar ORR/DEM products to be made for those missions. For the fixed landers and Spirit, we will compile merged surface/CTX/HiRISE ORR/DEMs, that will enable accurate local and regional mapping of these landing sites, and allow comparisons of the results from these missions to be made with current and future surface missions.

NASA Design Projects at UC Berkeley for NASA's HEDS-UP Program

NASA Astrophysics Data System (ADS)

Kuznetz, Lawrence

1998-01-01

Missions to Mars have been a topic for study since the advent of the space age. But funding has been largely reserved for the unmanned probes such as Viking, Pathfinder and Global Surveyer. Financial and political constraints have relegated human missions, on the other hand, to backroom efforts such as the Space Exploration Initiative (SEI) of 1989-1990. With the new found enthusiasm from Pathfinder and the meteorite ALH84001, however, there is renewed interest in human exploration of Mars. This is manifest in the new Human Exploration and Development of Space (HEDS) program that NASA has recently initiated. This program, through its University Projects (HEDS-UP) office has taken the unusual step of soliciting creative solutions from universities. For its part in the HEDS-UP program, the University of California at Berkeley was asked to study the issues of Habitat design, Space Suits for Mars, Environmental Control and Life Support Systems, Countermeasures to Hypogravity and Crew Size/Mix. These topics were investigated as design projects in "Mars by 2012", an on-going class for undergraduates and graduate students. The methodology of study was deemed to be as important as the design projects themselves and for that we were asked to create an Interactive Design Environment. The Interactive Design Environment (IDE) is an electronic "office" that allows scientists and engineers, as well as other interested parties, to interact with and critique engineering designs as they progress. It usually takes the form of a website that creates a "virtual office" environment. That environment is a place where NASA and others can interact with and critique the university designs for potential inclusion in the Mars Design Reference Mission.

Rock Abrasion on Mars: Clues from the Pathfinder and Viking Landing Sites

NASA Technical Reports Server (NTRS)

Bridges, N. T.; Parker, T. J.; Kramer, G. M.

2000-01-01

A significant discovery of the Mars Pathfinder (MPF) mission was that many rocks exhibit characteristics of ventifacts, rocks that have been sculpted by saltating particles. Diagnostic features identifying the rocks as ventifacts am elongated pits, flutes, and grooves (collectively referred to as "flutes" unless noted otherwise). Faceted rocks or rock portions, circular pits, rills, and possibly polished rock surfaces are also seen and could be due, to aeolian abrasion. Many of these features were initially identified in rover images, where spatial resolution generally exceeded that of the IMP (Imager for Mars Pathfinder) camera. These images had two major limitations: 1) Only a limited number of rocks were viewed by the rover, biasing flute statistics; and 2) The higher resolution obtained by the rover images and the lack of such pictures at the Viking landing sites hampered comparisons of rock morphologies between the Pathfinder and Viking sites. To avoid this problem, rock morphology and ventifact statistics have been examined using new "super-resolution" IMP and Viking Lander images. Analyses of these images show that: 1) Flutes are seen on about 50% or more of the rocks in the near field at the MPF site; 2) The orientation of these flutes is similar to that for flutes identified in rover images; and 3) Ventifacts are significantly more abundant at the Pathfinder landing site than at the two Viking Landing sites, where rocks have undergone only a limited amount of aeolian abrasion. This is most likely due to the ruggedness of the Pathfinder site and a greater supply of abrading particles available shortly after the Arcs and Tiu Valles outflow channel floods.

Results of the Imager for Mars Pathfinder windsock experiment

USGS Publications Warehouse

Sullivan, R.; Greeley, R.; Kraft, M.; Wilson, G.; Golombek, M.; Herkenhoff, K.; Murphy, J.; Smith, P.

2000-01-01

The Imager for Mars Pathfinder (IMP) windsock experiment measured wind speeds at three heights within 1.2 m of the Martian surface during Pathfinder landed operations. These wind data allowed direct measurement of near-surface wind profiles on Mars for the first time, including determination of aerodynamic roughness length and wind friction speeds. Winds were light during periods of windsock imaging, but data from the strongest breezes indicate aerodynamic roughness length of 3 cm at the landing site, with wind friction speeds reaching 1 m/s. Maximum wind friction speeds were about half of the threshold-of-motion friction speeds predicted for loose, fine-grained materials on smooth Martian terrain and about one third of the threshold-of-motion friction speeds predicted for the same size particles over terrain with aerodynamic roughness of 3 cm. Consistent with this, and suggesting that low wind speeds prevailed when the windsock array was not imaged and/or no particles were available for aeolian transport, no wind-related changes to the surface during mission operations have been recognized. The aerodynamic roughness length reported here implies that proposed deflation of fine particles around the landing site, or activation of duneforms seen by IMP and Sojourner, would require wind speeds >28 m/s at the Pathfinder top windsock height (or >31 m/s at the equivalent Viking wind sensor height of 1.6 m) and wind speeds >45 m/s above 10 m. These wind speeds would cause rock abrasion if a supply of durable particles were available for saltation. Previous analyses indicate that the Pathfinder landing site probably is rockier and rougher than many other plains units on Mars, so aerodynamic roughness length elsewhere probably is less than the 3-cm value reported for the Pathfinder site. Copyright 2000 by the American Geophysical Union.

Curricular/Instructional Technology Resources.

ERIC Educational Resources Information Center

Roy, Loriene, Comp.

Part of a larger report on the Four Directions Project, an American Indian technology innovation project, this section includes 10 "pathfinders" to locating information on learning and instructional technology resources. The pathfinders were designed by students in the Graduate School of Library and Information Science at the University…

Internet Technology Resources.

ERIC Educational Resources Information Center

Roy, Loriene, Comp.

Part of a larger report on the Four Directions Project, an American Indian technology innovation project, this section includes six "pathfinders" to locating information on Internet resources. The pathfinders were designed by students in the Graduate School of Library and Information Science at the University of Texas at Austin in…

Cultural Themes.

ERIC Educational Resources Information Center

Roy, Loriene, Comp.

Part of a larger report on the Four Directions Project, an American Indian technology innovation project, this section includes 10 "pathfinders" to locating information on Native American cultural themes. The pathfinders were designed by students in the Graduate School of Library and Information Science at the University of Texas at…

Correspondence and Least Squares Analyses of Soil and Rock Compositions for the Viking Lander 1 and Pathfinder Sites

NASA Technical Reports Server (NTRS)

Larsen, K. W.; Arvidson, R. E.; Jolliff, B. L.; Clark, B. C.

2000-01-01

Correspondence and Least Squares Mixing Analysis techniques are applied to the chemical composition of Viking 1 soils and Pathfinder rocks and soils. Implications for the parent composition of local and global materials are discussed.

Soil disturbance by airbags

NASA Technical Reports Server (NTRS)

1997-01-01

Disturbance of the drift at the Pathfinder landing site reveals a shallow subsurface that is slightly darker but has similar spectral properties. The top set of images, in true color, shows the soils disturbed by the last bounce of the lander on its airbags before coming to rest and the marks created by retraction of the airbags. In the bottom set of images color differences have been enhanced. The mast at center is the Atmospheric Structure Instrument/Meteorology Package (ASI/MET). The ASI/MET is an engineering subsytem that acquired atmospheric data during Pathfinder's descent, and will continue to get more data through the entire landed mission. A shadow of the ASI/MET appears on a rock at left.

Mars Pathfinder was developed and managed by the Jet Propulsion Laboratory (JPL) for the National Aeronautics and Space Administration. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Atmosphere Processing Module Automation and Catalyst Durability Analysis for Mars ISRU Pathfinder

NASA Technical Reports Server (NTRS)

Petersen, Elspeth M.

2016-01-01

The Mars In-Situ Resource Utilization Pathfinder was designed to create fuel using components found in the planet’s atmosphere and regolith for an ascension vehicle to return a potential sample return or crew return vehicle from Mars. The Atmosphere Processing Module (APM), a subunit of the pathfinder, uses cryocoolers to isolate and collect carbon dioxide from Mars simulant gas. The carbon dioxide is fed with hydrogen into a Sabatier reactor where methane is produced. The APM is currently undergoing the final stages of testing at Kennedy Space Center prior to process integration testing with the other subunits of the pathfinder. The automation software for the APM cryocoolers was tested and found to perform nominally. The catalyst used for the Sabatier reactor was investigated to determine the factors contributing to catalyst failure. The results from the catalyst testing require further analysis, but it appears that the rapid change in temperature during reactor start up or the elevated operating temperature is responsible for the changes observed in the catalyst.

Distributed Active Archive Center

NASA Technical Reports Server (NTRS)

Bodden, Lee; Pease, Phil; Bedet, Jean-Jacques; Rosen, Wayne

1993-01-01

The Goddard Space Flight Center Version 0 Distributed Active Archive Center (GSFC V0 DAAC) is being developed to enhance and improve scientific research and productivity by consolidating access to remote sensor earth science data in the pre-EOS time frame. In cooperation with scientists from the science labs at GSFC, other NASA facilities, universities, and other government agencies, the DAAC will support data acquisition, validation, archive and distribution. The DAAC is being developed in response to EOSDIS Project Functional Requirements as well as from requirements originating from individual science projects such as SeaWiFS, Meteor3/TOMS2, AVHRR Pathfinder, TOVS Pathfinder, and UARS. The GSFC V0 DAAC has begun operational support for the AVHRR Pathfinder (as of April, 1993), TOVS Pathfinder (as of July, 1993) and the UARS (September, 1993) Projects, and is preparing to provide operational support for SeaWiFS (August, 1994) data. The GSFC V0 DAAC has also incorporated the existing data, services, and functionality of the DAAC/Climate, DAAC/Land, and the Coastal Zone Color Scanner (CZCS) Systems.

Pathfinder, Volume 7, Number 5, September/October 2009. Charting the Sea and Sky

DTIC Science & Technology

2009-10-01

During the six-month season, ski-equipped LC-130s, the polar version of the C-130 Hercules transport plane, flew more than 8.7 million pounds of...collaborate closely with the Space and Naval Warfare Systems Command (SPAWAR), Office of Polar Programs; the Federal Avia- tion Administration (FAA...only worldwide vector chart coverage. Recently, the Navy implemented polar navigation using NGA charts and is now capable of true worldwide digital

Model Checking Real Time Java Using Java PathFinder

NASA Technical Reports Server (NTRS)

Lindstrom, Gary; Mehlitz, Peter C.; Visser, Willem

2005-01-01

The Real Time Specification for Java (RTSJ) is an augmentation of Java for real time applications of various degrees of hardness. The central features of RTSJ are real time threads; user defined schedulers; asynchronous events, handlers, and control transfers; a priority inheritance based default scheduler; non-heap memory areas such as immortal and scoped, and non-heap real time threads whose execution is not impeded by garbage collection. The Robust Software Systems group at NASA Ames Research Center has JAVA PATHFINDER (JPF) under development, a Java model checker. JPF at its core is a state exploring JVM which can examine alternative paths in a Java program (e.g., via backtracking) by trying all nondeterministic choices, including thread scheduling order. This paper describes our implementation of an RTSJ profile (subset) in JPF, including requirements, design decisions, and current implementation status. Two examples are analyzed: jobs on a multiprogramming operating system, and a complex resource contention example involving autonomous vehicles crossing an intersection. The utility of JPF in finding logic and timing errors is illustrated, and the remaining challenges in supporting all of RTSJ are assessed.

Diversity of soils near rover deploy region

NASA Technical Reports Server (NTRS)

1997-01-01

The surface near the rover's egress from the lander contains bright red drift (#1), dark gray rocks such as Cradle (#3), soil intermediate in color to the rocks and drift (#2), and dark red soil on and around the rock Lamb (#4). Globally, Mars is characterized by similar color variations. The spectra of these sites have been ratioed to the drift to highlight their differences. The rocks are less red and have less of a bend in the spectrum at visible wavelengths, indicating less ferric minerals and a more unweathered composition than drift. The intermediate colored soils appear intermediate in the spectral properties as well. The dark red soil at Lamb is darker than drift by about equally as red; the curvature of spectrum at visible wavelengths indicates either more ferric minerals or a larger particle size.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech).

PATHFINDER: Probing Atmospheric Flows in an Integrated and Distributed Environment

NASA Technical Reports Server (NTRS)

Wilhelmson, R. B.; Wojtowicz, D. P.; Shaw, C.; Hagedorn, J.; Koch, S.

1995-01-01

PATHFINDER is a software effort to create a flexible, modular, collaborative, and distributed environment for studying atmospheric, astrophysical, and other fluid flows in the evolving networked metacomputer environment of the 1990s. It uses existing software, such as HDF (Hierarchical Data Format), DTM (Data Transfer Mechanism), GEMPAK (General Meteorological Package), AVS, SGI Explorer, and Inventor to provide the researcher with the ability to harness the latest in desktop to teraflop computing. Software modules developed during the project are available in the public domain via anonymous FTP from the National Center for Supercomputing Applications (NCSA). The address is ftp.ncsa.uiuc.edu, and the directory is /SGI/PATHFINDER.

Pathfinder: A Retrospective

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.; Lyons, Valerie (Technical Monitor)

2002-01-01

Mars is one of the most interesting planets in the solar system, featuring enormous canyons, giant volcanoes, and indications that, early in its history, it might have had rivers and perhaps even oceans. Five years ago, in July of 1997, the Pathfinder mission landed on Mars, bringing with it the microwave-oven sized Sojourner rover to wander around on the surface and analyse rocks. Among the experiments on the mission was one designed to analyse dust deposition. Pathfinder is only the first of an armada of spacecraft which will examine Mars from the pole to the equator in the next decade, culminating with a mission to bring humans to Mars.

Holographic beam mapping of the CHIME pathfinder array

NASA Astrophysics Data System (ADS)

Berger, Philippe; Newburgh, Laura B.; Amiri, Mandana; Bandura, Kevin; Cliche, Jean-François; Connor, Liam; Deng, Meiling; Denman, Nolan; Dobbs, Matt; Fandino, Mateus; Gilbert, Adam J.; Good, Deborah; Halpern, Mark; Hanna, David; Hincks, Adam D.; Hinshaw, Gary; Höfer, Carolin; Johnson, Andre M.; Landecker, Tom L.; Masui, Kiyoshi W.; Mena Parra, Juan; Oppermann, Niels; Pen, Ue-Li; Peterson, Jeffrey B.; Recnik, Andre; Robishaw, Timothy; Shaw, J. Richard; Siegel, Seth; Sigurdson, Kris; Smith, Kendrick; Storer, Emilie; Tretyakov, Ian; Van Gassen, Kwinten; Vanderlinde, Keith; Wiebe, Donald

2016-08-01

The Canadian Hydrogen Intensity Mapping Experiment (CHIME) Pathfinder radio telescope is currently surveying the northern hemisphere between 400 and 800 MHz. By mapping the large scale structure of neutral hydrogen through its redshifted 21 cm line emission between z 0.8-2.5 CHIME will contribute to our understanding of Dark Energy. Bright astrophysical foregrounds must be separated from the neutral hydrogen signal, a task which requires precise characterization of the polarized telescope beams. Using the DRAO John A. Galt 26 m telescope, we have developed a holography instrument and technique for mapping the CHIME Pathfinder beams. We report the status of the instrument and initial results of this effort.

Pathfinder, v6 n6, Nov/Dec 2008. Foundation Data and Technology

DTIC Science & Technology

2008-12-01

Geospatial-Intelligence Agency,Office of Corporate Communications,4600 Sangamore Road ,Bethesda,MD, 20816 -5003 8. PERFORMING ORGANIZATION REPORT...Communications 4600 Sangamore Road, Mail Stop D-54 Bethesda, MD 20816 -5003 Telephone: (301) 227-7388, DSN 287-7388 E-mail: pathfinder@nga.mil

A Pathfinder for Animal Research and Animal Rights.

ERIC Educational Resources Information Center

Anderson, David C.

1992-01-01

This pathfinder was originally prepared for "Biomedical Research and Animal Rights," a session sponsored by the Veterinary Medical Libraries and Research Libraries Sections of the Medical Library Association. Current resources are described, from bibliographies to electronic bulletin boards, which relate to the issue of laboratory animal…

Is it feasible to pool funds for local children's services in England? Evidence from the national evaluation of children's trust pathfinders.

PubMed

Lorgelly, Paula; Bachmann, Max; Shreeve, Ann; Reading, Richard; Thorburn, June; Mugford, Miranda; O'Brien, Margaret; Husbands, Chris

2009-01-01

To describe how funds were pooled or otherwise jointly managed by National Health Service (NHS) primary care trusts and local authorities in England. To compare expenditure on local children's services by health, education and social services. We conducted a questionnaire survey of all 35 children's trust pathfinders, six months after they were launched, with a follow-up at 2.5 years. We also undertook an in-depth analysis of local authorities and primary care trusts, within eight pathfinder areas and three non-pathfinder areas, whereby we compared expenditure on children's services, interviewed managers and professionals and examined financial documents. Local authorities and NHS trusts coordinated expenditure in various ways, most commonly through informal agreements and aligning budgets but also by formally pooling budgets. The latter were usually for selected services such as child and adolescent mental health services, though four children's trusts pathfinders pooled (or aligned) their budgets for all children's services. Total expenditure per child was greatest for education, lowest for social services and intermediate for health. However, it was difficult to quantify education expenditure on children with health and social care needs, and health care expenditure on children. Sharing money for local children's services requires shared objectives, trust, and legal and accounting expertise. Several different mechanisms are permitted and many are feasible but programme budgeting for children's services could make them more effective.

Uncoupling nicotine mediated motoneuron axonal pathfinding errors and muscle degeneration in zebrafish

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

Welsh, Lillian; Tanguay, Robert L.; Svoboda, Kurt R.

Zebrafish embryos offer a unique opportunity to investigate the mechanisms by which nicotine exposure impacts early vertebrate development. Embryos exposed to nicotine become functionally paralyzed by 42 hpf suggesting that the neuromuscular system is compromised in exposed embryos. We previously demonstrated that secondary spinal motoneurons in nicotine-exposed embryos were delayed in development and that their axons made pathfinding errors (Svoboda, K.R., Vijayaraghaven, S., Tanguay, R.L., 2002. Nicotinic receptors mediate changes in spinal motoneuron development and axonal pathfinding in embryonic zebrafish exposed to nicotine. J. Neurosci. 22, 10731-10741). In that study, we did not consider the potential role that altered skeletalmore » muscle development caused by nicotine exposure could play in contributing to the errors in spinal motoneuron axon pathfinding. In this study, we show that an alteration in skeletal muscle development occurs in tandem with alterations in spinal motoneuron development upon exposure to nicotine. The alteration in the muscle involves the binding of nicotine to the muscle-specific AChRs. The nicotine-induced alteration in muscle development does not occur in the zebrafish mutant (sofa potato, [sop]), which lacks muscle-specific AChRs. Even though muscle development is unaffected by nicotine exposure in sop mutants, motoneuron axonal pathfinding errors still occur in these mutants, indicating a direct effect of nicotine exposure on nervous system development.« less

Advanced physical-chemical life support systems research

NASA Technical Reports Server (NTRS)

Evanich, Peggy L.

1988-01-01

A proposed NASA space research and technology development program will provide adequate data for designing closed loop life support systems for long-duration manned space missions. This program, referred to as the Pathfinder Physical-Chemical Closed Loop Life Support Program, is to identify and develop critical chemical engineering technologies for the closure of air and water loops within the spacecraft, surface habitats or mobility devices. Computerized simulation can be used both as a research and management tool. Validated models will guide the selection of the best known applicable processes and in the development of new processes. For the integration of the habitat system, a biological subsystem would be introduced to provide food production and to enhance the physical-chemical life support functions on an ever-increasing basis.

The Pathfinder Microrover

NASA Technical Reports Server (NTRS)

Matijevic, J. R.; Bickler, D. B.; Braun, D. F.; Eisen, H. J.; Matthies, L. H.; Mishkin, A. H.; Stone, H. W.; van Nieuwstadt, L. M.; Wen, L. C.; Wilcox, B. H.;

Pathfinders: An Intellectual Guide to Libraries.

ERIC Educational Resources Information Center

Jung, Claudia Ruediger; And Others

Intended as an example for other college libraries, this collection of 38 pathfinders and bibliographies was developed by the reference staff of the Calvin Coolidge Library at Castleton State College, Vermont. Designed to present the types of literature available in particular subject fields and those works readily available in the Coolidge…

Pathfinder Teaching and Learning Units.

ERIC Educational Resources Information Center

Hawaii Univ., Honolulu. Sea Grant Program.

This collection of teaching units were selected from materials developed during the Operation Pathfinder Institutes (OPI) which took place in the Pacific region between 1994 and 1999. The institutes were intended to provide upper elementary and middle school science teachers with an opportunity to develop a deeper understanding of the marine…

Sedimentary geomorphology of the Mars Pathfinder Landing Site

NASA Technical Reports Server (NTRS)

Rice, James W., Jr.; Parker, Timothy Jay

1997-01-01

The first landing on Mars in over 20 years will take place July 4, 1997, near te mouth of the Ares Vallis outflow channel located in southeastern Chryse Planitia. Mars Pathfinder, unlike Viking 1, is expected to land on a surface that has a distinct and unambiguous fluvial signature.

Teacher Job Satisfaction: Lessons from the TSW Pathfinder Project

ERIC Educational Resources Information Center

Butt, Graham; Lance, Ann; Fielding, Antony; Gunter, Helen; Rayner, Steve; Thomas, Hywel

2005-01-01

Government policy assumes that modernization and remodelling will be effective as external intervention mechanisms to improve job satisfaction. Based on data collected as part of the evaluation of the "Transforming the School Workforce Pathfinder Project", an argument is presented here which suggests that internal management models may…

Airbag Retraction

NASA Image and Video Library

1997-07-05

This image shows that the Mars Pathfinder airbags have been successfully retracted, allowing safe deployment of the rover ramps. The Sojourner rover is at lower right, and rocks are visible in the background. Mars Pathfinder landed successfully on the surface of Mars today at 10:07 a.m. PDT. http://photojournal.jpl.nasa.gov/catalog/PIA00618

Pathfinders on Black Dance in America.

ERIC Educational Resources Information Center

Roy, Loriene, Ed.

This is a compilation of 18 pathfinders (i.e., a bibliographic instruction aid) on black dance in America, prepared by graduate students in the "Information Resources in the Humanities" and the "Information Resources in the Social Sciences" classes in the Graduate School of Library and Information Science at the University of…

Mechanical design of the Mars Pathfinder mission

NASA Technical Reports Server (NTRS)

Eisen, Howard Jay; Buck, Carl W.; Gillis-Smith, Greg R.; Umland, Jeffrey W.

1997-01-01

The Mars Pathfinder mission and the Sojourner rover is reported on, with emphasis on the various mission steps and the performance of the technologies involved. The mechanical design of mission hardware was critical to the success of the entry sequence and the landing operations. The various mechanisms employed are considered.

Pathfinder, Volume 7. Number 4, Jul/Aug 2009. GEOINT in Action

DTIC Science & Technology

2009-08-01

Rd,Bethesda,MD, 20816 -5003 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S...Communications 4600 Sangamore Road, Mail Stop D-39 Bethesda, MD 20816 -5003 Telephone: (301) 227-7388, DSN 287-7388 E-mail: pathfinder@nga.mil

Pathfinder, v6 n3, May/Jun 2008. Unifying the Intelligence Profession

DTIC Science & Technology

2008-06-01

ADDRESS(ES) National Geospatial-Intelligence Agency,Office of Corporate Communications,4600 Sangamore Road ,Bethesda,MD, 20816 -5003 8. PERFORMING...Sangamore Road, Mail Stop D-54 Bethesda, MD 20816 -5003 Telephone: (301) 227-7388, DSN 287-7388 E-mail: pathfinder@nga.mil Director Vice Adm. Robert

Pathfinder, v6 n5, Sep/Oct 2008. Shielding Our Home and Nation

DTIC Science & Technology

2008-10-01

Agency,Office of Corporate Communications,4600 Sangamore Road ,Bethesda,MD, 20816 -5003 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING... 20816 -5003 Telephone: (301) 227-7388, DSN 287-7388 E-mail: pathfinder@nga.mil Director Vice Adm. Robert B. Murrett, U.S. Navy Deputy Director

The Twin Peaks in 3-D, as Viewed by the Mars Pathfinder IMP Camera

NASA Image and Video Library

1997-11-04

Twin Peaks are modest-size hills to the southwest of NASA Mars Pathfinder landing site. They were discovered on the first panoramas taken by the IMP camera on the 4th of July, 1997. 3D glasses are necessary to identify surface detail.

Conversations: with Carl Pilcher [interview by Johan Benson].

PubMed

Pilcher, C

1998-11-01

An interview with Carl Pilcher, science program director for solar system exploration at NASA, examines NASA's past, present, and planned missions to explore the solar system. Specific questions relate to the status of current and planned missions, science results of the Pathfinder mission to Mars, cooperation with the Japanese space agency, the status of the search for extraterrestrial life in solar system meteoroids and asteroids, mission size for more in-depth exploration, reports of water on the moon, and the exploration of near-Earth objects.

Progress Towards a Space-Based Gravitational-Wave Observatory Since 2010

NASA Technical Reports Server (NTRS)

Stebbins, Robin T.

2015-01-01

Laser Interferometer Space Antenna (LISA): Focus of all work since 1993; Unchanged since 1997; Project in Phase A since 2004; Extensive formulation work and products; Reviewed and recommended in many major reviews: AANM (NRC, 2001), TRIP (HQ, 2003), Connecting Quarks with the Cosmos (NRC, 2003), AETD (GSFC, 2005). Beyond Einstein Program: (NRC, 2007), NWNH (NRC, 2010): Second in large space projects after WFIRST. Recommended for a new start. Contingent on Lisa Pathfinder success and a roughly 50-50 European partnership.

Pathfinder

NASA Image and Video Library

1997-06-04

This shot offers a bird's eye-view of a Fastrac II engine duration test at Marshall's Test Stand 116. The Fastrac II engine was designed as a part of the low cost X-34 Reusable Launch Vehicle (RLV). The purpose for these tests was to test the different types of metal alloys in the nozzle. Beside the engine were six additional nozzels which spray a continuous stream of water onto the test stand to reduce damage to the test stand and the engines. The X-34 program was cancelled in 2001.

Path finding methods accounting for stoichiometry in metabolic networks

PubMed Central

2011-01-01

Graph-based methods have been widely used for the analysis of biological networks. Their application to metabolic networks has been much discussed, in particular noting that an important weakness in such methods is that reaction stoichiometry is neglected. In this study, we show that reaction stoichiometry can be incorporated into path-finding approaches via mixed-integer linear programming. This major advance at the modeling level results in improved prediction of topological and functional properties in metabolic networks. PMID:21619601

Digital photogrammetric analysis of the IMP camera images: Mapping the Mars Pathfinder landing site in three dimensions

USGS Publications Warehouse

Kirk, R.L.; Howington-Kraus, E.; Hare, T.; Dorrer, E.; Cook, D.; Becker, K.; Thompson, K.; Redding, B.; Blue, J.; Galuszka, D.; Lee, E.M.; Gaddis, L.R.; Johnson, J. R.; Soderblom, L.A.; Ward, A.W.; Smith, P.H.; Britt, D.T.

1999-01-01

This paper describes our photogrammetric analysis of the Imager for Mars Pathfinder data, part of a broader program of mapping the Mars Pathfinder landing site in support of geoscience investigations. This analysis, carried out primarily with a commercial digital photogrammetric system, supported by our in-house Integrated Software for Imagers and Spectrometers (ISIS), consists of three steps: (1) geometric control: simultaneous solution for refined estimates of camera positions and pointing plus three-dimensional (3-D) coordinates of ???103 features sitewide, based on the measured image coordinates of those features; (2) topographic modeling: identification of ???3 ?? 105 closely spaced points in the images and calculation (based on camera parameters from step 1) of their 3-D coordinates, yielding digital terrain models (DTMs); and (3) geometric manipulation of the data: combination of the DTMs from different stereo pairs into a sitewide model, and reprojection of image data to remove parallax between the different spectral filters in the two cameras and to provide an undistorted planimetric view of the site. These processes are described in detail and example products are shown. Plans for combining the photogrammetrically derived topographic data with spectrophotometry are also described. These include photometric modeling using surface orientations from the DTM to study surface microtextures and improve the accuracy of spectral measurements, and photoclinometry to refine the DTM to single-pixel resolution where photometric properties are sufficiently uniform. Finally, the inclusion of rover images in a joint photogrammetric analysis with IMP images is described. This challenging task will provide coverage of areas hidden to the IMP, but accurate ranging of distant features can be achieved only if the lander is also visible in the rover image used. Copyright 1999 by the American Geophysical Union.

Super Resolution Image of Yogi

NASA Technical Reports Server (NTRS)

1997-01-01

Yogi is a meter-size rock about 5 meters northwest of the Mars Pathfinder lander and was the second rock visited by the Sojourner Rover's alpha proton X-ray spectrometer (APXS) instrument. This mosaic shows super resolution techniques applied to the second APXS target rock, which was poorly illuminated in the rover's forward camera view taken before the instrument was deployed. Super resolution was applied to help to address questions about the texture of this rock and what it might tell us about its mode of origin.

This mosaic of Yogi was produced by combining four 'Super Pan' frames taken with the IMP camera. This composite color mosaic consists of 7 frames from the right eye, taken with different color filters that were enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution panchromatic frame that is sharper than an individual frame would be. This panchromatic frame was then colorized with the red, green, and blue filtered images from the same sequence. The color balance was adjusted to approximate the true color of Mars. Shadows were processed separately from the rest of the rock and combined with the rest of the scene to bring out details in the shadow of Yogi that would be too dark to view at the same time as the sunlit surfaces.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Topographic Map of Pathfinder Landing Site

NASA Technical Reports Server (NTRS)

1997-01-01

Topographic map of the landing site, to a distance of 60 meters from the lander in the LSC coordinate system. The lander is shown schematically in the center; 2.5 meter radius circle (black) centered on the camera was not mapped. Gentle relief [root mean square (rms) elevation variation 0.5 m; rms a directional slope 4O] and organization of topography into northwest and northeast-trending ridges about 20 meters apart are apparent. Roughly 30% of the illustrated area is hidden from the camera behind these ridges. Contours (0.2 m interval) and color coding of elevations were generated from a digital terrain model, which was interpolated by kriging from approximately 700 measured points. Angular and parallax point coordinates were measured manually on a large (5 m length) anaglyphic uncontrolled mosaic and used to calculate Cartesian (LSC) coordinates. Errors in azimuth on the order of 10 are therefore likely; elevation errors were minimized by referencing elevations to the local horizon. The uncertainty in range measurements increases quadratically with range. Given a measurement error of 1/2 pixel, the expected precision in range is 0.3 meter at 10 meter range, and 10 meters at 60 meter range. Repeated measurements were made, compared, and edited for consistency to improve the range precision. Systematic errors undoubtedly remain and will be corrected in future maps compiled digitally from geometrically controlled images. Cartographic processing by U.S. Geological Survey.

NOTE: original caption as published in Science Magazine

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Interface Generation and Compositional Verification in JavaPathfinder

NASA Technical Reports Server (NTRS)

Giannakopoulou, Dimitra; Pasareanu, Corina

2009-01-01

We present a novel algorithm for interface generation of software components. Given a component, our algorithm uses learning techniques to compute a permissive interface representing legal usage of the component. Unlike our previous work, this algorithm does not require knowledge about the component s environment. Furthermore, in contrast to other related approaches, our algorithm computes permissive interfaces even in the presence of non-determinism in the component. Our algorithm is implemented in the JavaPathfinder model checking framework for UML statechart components. We have also added support for automated assume-guarantee style compositional verification in JavaPathfinder, using component interfaces. We report on the application of the presented approach to the generation of interfaces for flight software components.

Review of the trajectory and atmospheric structure reconstruction for Mars Pathfinder

NASA Astrophysics Data System (ADS)

Withers, Paul; Towner, Martin; Hathi, Brijen; Zarnecki, John

2004-02-01

Mars Pathfinder landed on Mars on July 4, 1997. It used a novel deceleration procedure, consisting of a hypersonic aeroshell, a transonic parachute, retro-rockets, and airbags, to reach the surface safely. Its aerodynamic properties passively maintained a near-zero angle of attack throughout its entry. There were no gyroscopes to monitor attitude. Several different trajectory reconstructions have been based on the assumptions that accelerations along its symmetry axis are directed along its flight path and that accelerations in other directions are insignificant. The aerodynamics of Pathfinder once its parachute opened are still not well-understood and the available observations are probably not sufficient to improve matters significantly in the future.

James Webb Space Telescope Optical Telescope Element Integrated Science Instrument Module (OTIS) Status

NASA Technical Reports Server (NTRS)

Feinberg, Lee; Voyton, Mark; Lander, Julie; Keski-Kuha, Ritva; Matthews, Gary

2016-01-01

The James Webb Space Telescope Optical Telescope Element (OTE) and Integrated ScienceInstrument Module (ISIM)are integrated together to form the OTIS. Once integrated, the OTIS undergoes primary mirrorcenter of curvatureoptical tests, electrical and operational tests, acoustics and vibration testing at the Goddard SpaceFlight Center beforebeing shipped to the Johnson Space Center for cryogenic optical testing of the OTIS. In preparationfor the cryogenicoptical testing, the JWST project has built a Pathfinder telescope and has completed two OpticalGround SystemEquipment (OGSE) cryogenic optical tests with the Pathfinder. In this paper, we will summarize opticaltest results todate and status the final Pathfinder test and the OTIS integration and environmental test preparations

HOWARD EISEN, JPL'S LEAD MECHANICAL TECHNICIAN, HOLDS MARS PATHFINDER 'SOJOURNER' ROVER 1:1 SCALE DU

NASA Technical Reports Server (NTRS)

1996-01-01

The Mars Pathfinder 'Sojourner' rover l:l scale duplicate test vehicle is held by Howard Eisen, its lead mechanical technician from the Jet Propulsion Laboratory, with Kennedy Space Center's Vehicle Assembly Building looming in the background. The launch of NASA's Mars Pathfinder spacecraft aboard a McDonnell Douglas Delta II rocket is scheduled for Monday, Dec. 2, at 2:09:11 a.m. EST. This is a single instantaneous target launch time without a second opportunity on that day. Liftoff will occur from Pad B at Launch Complex 17 on Cape Canaveral Air Station, Fla. There is a 24-day launch opportunity which extends through Dec. 31.

LISA Pathfinder: A Mission Status

NASA Astrophysics Data System (ADS)

Hewitson, Martin; LISA Pathfinder Team Team

2016-03-01

On December 3rd at 04:04 UTC, The European Space Agency launched the LISA Pathfinder satellite on board a VEGA rocket from Kourou in French Guiana. After a series of orbit raising manoeuvres and a 2 month long transfer orbit, LISA Pathfinder arrived at L1. Following a period of commissioning, the science operations commenced at the start of March, beginning the demonstration of technologies and methodologies which pave the way for a future large-scale gravitational wave observatory in space. This talk will present the scientific goals of the mission, discuss the technologies being tested, elucidate the link to a future space-based observatory, such as LISA, and present preliminary results from the in-orbit operations and experiments.

AeroVironment's Jim Daley, Rik Meininger, Derek Lisoski and Wyatt Sadler (clockwise from bottom left) closely monitor systems testing of the Pathfinder-Plus.

NASA Image and Video Library

2004-09-17

AeroVironment's test director Jim Daley, backup pilot Rik Meininger, stability and controls engineer Derek Lisoski and pilot Wyatt Sadler (clockwise from bottom left) closely monitor systems testing of the Pathfinder-Plus solar aircraft from the control station.

Do Integrated Children's Services Improve Children's Outcomes?: Evidence from England's Children's Trust Pathfinders

ERIC Educational Resources Information Center

O'Brien, Margaret; Bachmann, Max O.; Jones, Natalia R.; Reading, Richard; Thoburn, June; Husbands, Chris; Shreeve, Ann; Watson, Jacqueline

2009-01-01

Thirty-five children's trust pathfinders, local cross-sector partnerships, were introduced across England in 2003 to promote greater integration in children's services. Using administrative performance data, this paper tracks yearly trends in child service outputs and child well-being outcomes from 1997 to 2004 in these local areas, including the…

Global Climate Change Pathfinder: A Guide to Information Resources. Second Edition.

ERIC Educational Resources Information Center

Pintozzi, Chestalene; Jones, Douglas E.

This pathfinder is a guide to scientific and technical aspects of global climate change including meteorological and climatological aspects; biological, agricultural, and public policy implications; and the chemical processes involved. Sources are arranged by type of publication and include: (1) 10 reference sources; (2) 12 bibliographies; (3) 44…

Pathfinder. Volume 8, Number 3, May/June 2010. Technology - Rendering an Ever-Clearer Picture

DTIC Science & Technology

2010-06-01

Agency,Office of Corporate Communications,4600 Sangamore Road, Mail Stop D-54,Bethesda,MD, 20816 -5003 8. PERFORMING ORGANIZATION REPORT NUMBER 9...Bethesda, MD 20816 -5003 Telephone: (301) 227-7388, DSN 287-7388 E-mail: pathfinder@nga.mil Director Vice Adm. Robert B. Murrett, U.S. Navy Deputy

Statistical analysis of soil geochemical data to identify pathfinders associated with mineral deposits: An example from the Coles Hill uranium deposit, Virginia, USA

USGS Publications Warehouse

Levitan, Denise M.; Zipper, Carl E.; Donovan, Patricia; Schreiber, Madeline E.; Seal, Robert; Engle, Mark A.; Chermak, John A.; Bodnar, Robert J.; Johnson, Daniel K.; Aylor, Joseph G.

2015-01-01

Soil geochemical anomalies can be used to identify pathfinders in exploration for ore deposits. In this study, compositional data analysis is used with multivariate statistical methods to analyse soil geochemical data collected from the Coles Hill uranium deposit, Virginia, USA, to identify pathfinders associated with this deposit. Elemental compositions and relationships were compared between the collected Coles Hill soil and reference soil samples extracted from a regional subset of a national-scale geochemical survey. Results show that pathfinders for the Coles Hill deposit include light rare earth elements (La and Ce), which, when normalised by their Al content, are correlated with U/Al, and elevated Th/Al values, which are not correlated with U/Al, supporting decoupling of U from Th during soil generation. These results can be used in genetic and weathering models of the Coles Hill deposit, and can also be applied to future prospecting for similar U deposits in the eastern United States, and in regions with similar geological/climatic conditions.

MARS PATHFINDER CAMERA TEST IN SAEF-2

NASA Technical Reports Server (NTRS)

1996-01-01

Jet Propulsion Laboratory (JPL) workers conduct a systems test of the Mars Pathfinder imager, installed atop the Pathfinder lander (with JPL insignia). The imager is the white cyclindrical structure close to the worker's gloved hand. At left is the small rover that will be deployed from the lander to explore the Martian surface. The rover is mounted on one of three petals that will be attached to the lander. The two-pronged mast extending upward from the lander is for the low-gain antenna. The imager is mounted on a mast that will be extended after the lander touches down on Mars, affording a better view of the area. The imager is a camera that will transmit images of the Martian surface as well as the trail left by the rover, helping researchers to better understand the composition of the soil. It also is equipped with selectable filters for gathering data about the atmosphere of the Red Planet. JPL manages the Mars Pathfinder project for NASA. The journey to Mars is scheduled to begin with liftoff Dec. 2 aboard a Delta II expendable launch vehicle.

Actuation crosstalk in free-falling systems: Torsion pendulum results for the engineering model of the LISA pathfinder gravitational reference sensor

NASA Astrophysics Data System (ADS)

Bassan, M.; Cavalleri, A.; De Laurentis, M.; De Marchi, F.; De Rosa, R.; Di Fiore, L.; Dolesi, R.; Finetti, N.; Garufi, F.; Grado, A.; Hueller, M.; Marconi, L.; Milano, L.; Minenkov, Y.; Pucacco, G.; Stanga, R.; Vetrugno, D.; Visco, M.; Vitale, S.; Weber, W. J.

2018-01-01

In this paper we report on measurements on actuation crosstalk, relevant to the gravitational reference sensors for LISA Pathfinder and LISA. In these sensors, a Test Mass (TM) falls freely within a system of electrodes used for readout and control. These measurements were carried out on ground with a double torsion pendulum that allowed us to estimate both the torque injected into the sensor when a control force is applied and, conversely, the force leaking into the translational degree of freedom due to the applied torque.The values measured on our apparatus (the engineering model of the LISA Pathfinder sensor) agree to within 0.2% (over a maximum measured crosstalk of 1%) with predictions of a mathematical model when measuring force to torque crosstalk, while it is somewhat larger than expected (up to 3.5%) when measuring torque to force crosstalk. However, the values in the relevant range, i.e. when the TM is well centered ( ± 10 μm) in the sensor, remain smaller than 0.2%, satisfying the LISA Pathfinder requirements.

Relating MBSE to Spacecraft Development: A NASA Pathfinder

NASA Technical Reports Server (NTRS)

Othon, Bill

2016-01-01

The NASA Engineering and Safety Center (NESC) has sponsored a Pathfinder Study to investigate how Model Based Systems Engineering (MBSE) and Model Based Engineering (MBE) techniques can be applied by NASA spacecraft development projects. The objectives of this Pathfinder Study included analyzing both the products of the modeling activity, as well as the process and tool chain through which the spacecraft design activities are executed. Several aspects of MBSE methodology and process were explored. Adoption and consistent use of the MBSE methodology within an existing development environment can be difficult. The Pathfinder Team evaluated the possibility that an "MBSE Template" could be developed as both a teaching tool as well as a baseline from which future NASA projects could leverage. Elements of this template include spacecraft system component libraries, data dictionaries and ontology specifications, as well as software services that do work on the models themselves. The Pathfinder Study also evaluated the tool chain aspects of development. Two chains were considered: 1. The Development tool chain, through which SysML model development was performed and controlled, and 2. The Analysis tool chain, through which both static and dynamic system analysis is performed. Of particular interest was the ability to exchange data between SysML and other engineering tools such as CAD and Dynamic Simulation tools. For this study, the team selected a Mars Lander vehicle as the element to be designed. The paper will discuss what system models were developed, how data was captured and exchanged, and what analyses were conducted.

NASA's Webb "Pathfinder Telescope" Successfully Completes First Super-Cold Optical Test

NASA Image and Video Library

2017-12-08

Testing is crucial part of NASA's success on Earth and in space. So, as the actual flight components of NASA's James Webb Space Telescope come together, engineers are testing the non-flight equipment to ensure that tests on the real Webb telescope later goes safely and according to plan. Recently, the "pathfinder telescope," or just “Pathfinder,” completed its first super-cold optical test that resulted in many first-of-a-kind demonstrations. "This test is the first dry-run of the equipment and procedures we will use to conduct an end-to-end optical test of the flight telescope and instruments," said Mark Clampin, Webb telescope Observatory Project Scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "It provides confidence that once the flight telescope is ready, we are fully prepared for a successful test of the flight hardware." The Pathfinder is a non-flight replica of the Webb telescope’s center section backplane, or “backbone,” that includes mirrors. The flight backplane comes in three segments, a center section and two wing-like parts, all of which will support large hexagonal mirrors on the Webb telescope. The pathfinder only consists of the center part of the backplane. However, during the test, it held two full size spare primary mirror segments and a full size spare secondary mirror to demonstrate the ability to optically test and align the telescope at the planned operating temperatures of -400 degrees Fahrenheit (-240 Celsius). Read more: www.nasa.gov/feature/goddard/nasas-webb-pathfinder-telesc... Credit: NASA/Goddard/Chris Gunn NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Coexpression of high-voltage-activated ion channels Kv3.4 and Cav1.2 in pioneer axons during pathfinding in the developing rat forebrain.

PubMed

Huang, Chia-Yi; Chu, Dachen; Hwang, Wei-Chao; Tsaur, Meei-Ling

2012-11-01

Precise axon pathfinding is crucial for establishment of the initial neuronal network during development. Pioneer axons navigate without the help of preexisting axons and pave the way for follower axons that project later. Voltage-gated ion channels make up the intrinsic electrical activity of pioneer axons and regulate axon pathfinding. To elucidate which channel molecules are present in pioneer axons, immunohistochemical analysis was performed to examine 14 voltage-gated ion channels (Kv1.1-Kv1.3, Kv3.1-Kv3.4, Kv4.3, Cav1.2, Cav1.3, Cav2.2, Nav1.2, Nav1.6, and Nav1.9) in nine axonal tracts in the developing rat forebrain, including the optic nerve, corpus callosum, corticofugal fibers, thalamocortical axons, lateral olfactory tract, hippocamposeptal projection, anterior commissure, hippocampal commissure, and medial longitudinal fasciculus. We found A-type K⁺ channel Kv3.4 in both pioneer axons and early follower axons and L-type Ca²⁺ channel Cav1.2 in pioneer axons and early and late follower axons. Spatially, Kv3.4 and Cav1.2 were colocalized with markers of pioneer neurons and pioneer axons, such as deleted in colorectal cancer (DCC), in most fiber tracts examined. Temporally, Kv3.4 and Cav1.2 were expressed abundantly in most fiber tracts during axon pathfinding but were downregulated beginning in synaptogenesis. By contrast, delayed rectifier Kv channels (e.g., Kv1.1) and Nav channels (e.g., Nav1.2) were absent from these fiber tracts (except for the corpus callosum) during pathfinding of pioneer axons. These data suggest that Kv3.4 and Cav1.2, two high-voltage-activated ion channels, may act together to control Ca²⁺ -dependent electrical activity of pioneer axons and play important roles during axon pathfinding. Copyright © 2012 Wiley Periodicals, Inc.

Assessment of Mars Pathfinder landing site predictions

USGS Publications Warehouse

Golombek, M.P.; Moore, H.J.; Haldemann, A.F.C.; Parker, T.J.; Schofield, J.T.

1999-01-01

Remote sensing data at scales of kilometers and an Earth analog were used to accurately predict the characteristics of the Mars Pathfinder landing site at a scale of meters. The surface surrounding the Mars Pathfinder lander in Ares Vallis appears consistent with orbital interpretations, namely, that it would be a rocky plain composed of materials deposited by catastrophic floods. The surface and observed maximum clast size appears similar to predictions based on an analogous surface of the Ephrata Fan in the Channeled Scabland of Washington state. The elevation of the site measured by relatively small footprint delay-Doppler radar is within 100 m of that determined by two-way ranging and Doppler tracking of the spacecraft. The nearly equal elevations of the Mars Pathfinder and Viking Lander 1 sites allowed a prediction of the atmospheric conditions with altitude (pressure, temperature, and winds) that were well within the entry, descent, and landing design margins. High-resolution (~38 m/pixel) Viking Orbiter 1 images showed a sparsely cratered surface with small knobs with relatively low slopes, consistent with observations of these features from the lander. Measured rock abundance is within 10% of that expected from Viking orbiter thermal observations and models. The fractional area covered by large, potentially hazardous rocks observed is similar to that estimated from model rock distributions based on data from the Viking landing sites, Earth analog sites, and total rock abundance. The bulk and fine-component thermal inertias measured from orbit are similar to those calculated from the observed rock size-frequency distribution. A simple radar echo model based on the reflectivity of the soil (estimated from its bulk density), and the measured fraction of area covered by rocks was used to approximate the quasi-specular and diffuse components of the Earth-based radar echos. Color and albedo orbiter data were used to predict the relatively dust free or unweathered surface around the Pathfinder lander compared to the Viking landing sites. Comparisons with the experiences of selecting the Viking landing sites demonstrate the enormous benefit the Viking data and its analyses and models had on the successful predictions of the Pathfinder site. The Pathfinder experience demonstrates that, in certain locations, geologic processes observed in orbiter data can be used to infer surface characteristics where those processes dominate over other processes affecting the Martian surface layer. Copyright 1999 by the American Geophysical Union.

NASA's Discovery Program

NASA Astrophysics Data System (ADS)

Kicza, Mary; Bruegge, Richard Vorder

1995-01-01

NASA's Discovery Program represents an new era in planetary exploration. Discovery's primary goal: to maintain U.S. scientific leadership in planetary research by conducting a series of highly focused, cost effective missions to answer critical questions in solar system science. The Program will stimulate the development of innovative management approaches by encouraging new teaming arrangements among industry, universities and the government. The program encourages the prudent use of new technologies to enable/enhance science return and to reduce life cycle cost, and it supports the transfer of these technologies to the private sector for secondary applications. The Near-Earth Asteroid Rendezvous and Mars Pathfinder missions have been selected as the first two Discovery missions. Both will be launched in 1996. Subsequent, competitively selected missions will be conceived and proposed to NASA by teams of scientists and engineers from industry, academia, and government organizations. This paper summarizes the status of Discovery Program planning.

Airbag Retraction

NASA Image and Video Library

1997-07-05

This image shows that the Mars Pathfinder airbags have been successfully retracted, allowing safe deployment of the rover ramps. The Sojourner rover, still in its deployed position, is at center image, and rocks are visible in the background. Mars Pathfinder landed successfully on the surface of Mars today at 10:07 a.m. PDT. http://photojournal.jpl.nasa.gov/catalog/PIA00617

Pathfinder: The Geospatial Intelligence Magazine Serving the Front Line, March/April 2009. Volume 7, Number 2

DTIC Science & Technology

2009-04-01

ADDRESS(ES) National Geospatial-Intelligence Agency,4600 Sangamore Rd Mail Stop D-54,Bethesda,MD, 20816 -5003 8. PERFORMING ORGANIZATION REPORT NUMBER 9...Bethesda, MD 20816 -5003 Telephone: (301) 227-7388, DSN 287-7388 E-mail: pathfinder@nga.mil Director Vice Adm. Robert B. Murrett, U.S. Navy Deputy

Global comparisons between the modified Pathfinder derived sea surface temperature and skin temperatures from the along-track scanning radiometer on board ERS-2: how close are we getting?

NASA Technical Reports Server (NTRS)

Vazquez, J.

2001-01-01

Sea Surface Temperatures (SST) as derived from the Pathfinder Sea Surface Temperature Data Set and the Along-Track Scanning Radiometer on-board the European Remote Sensing Satellite provide a unique opportunity for comparing two independent SST data sets.

James Webb Space Telescope Optical Telescope Element/Integrated Science Instrument Module (OTIS) Status

NASA Technical Reports Server (NTRS)

Feinberg, Lee; Voyton, Mark; Lander, Juli; Keski-Kuha, Ritva; Matthews, Gary

2016-01-01

The James Webb Space Telescope Optical Telescope Element (OTE) and Integrated Science Instrument Module (ISIM) are integrated together to form the OTIS. Once integrated, the OTIS undergoes primary mirror center of curvature optical tests, electrical and operational tests, acoustics and vibration testing at the Goddard Space Flight Center before being shipped to the Johnson Space Center for cryogenic optical testing of the OTIS. In preparation for the cryogenic optical testing, the JWST project has built a Pathfinder telescope and has completed two Optical Ground System Equipment (OGSE) cryogenic optical tests with the Pathfinder. In this paper, we will summarize optical test results to date and status the final Pathfinder test and the OTIS integration and environmental test preparations

New Insights into the Geology of the Mars Pathfinder Landing Site from Spectral and Morphologic Analysis of the 12-Color Superpan Panorama

NASA Technical Reports Server (NTRS)

Murchie, S.; Barnouin-Jha, O.; Barnouin-Jha, K.; Bishop, J.; Johnson, J.; McSween, H.; Morris, R.

2003-01-01

New analyses of rocks and soils at the Mars Pathfinder landing site have been completed using the full Imager for Mars Pathfinder (IMP) 12- color SuperPan panorama. These revise early conclusions that rocks at the landing site are a single lithology coated only by windblown dust. We conclude instead that there is also a second lithology in addition to the dominant gray rock, and that it is consistent with highlands material excavated from beneath a thin veneer of northern plains; that many rocks have cemented coatings that formed during an early, probably wetter climate; and that young rocks excavated after coating formation ceased are mainly breccias or conglomerates.

LISA Pathfinder Spacecraft Artist Concept

NASA Image and Video Library

2015-12-03

This artist's concept shows ESA's LISA Pathfinder spacecraft, which launched on Dec. 3, 2015, from Kourou, French Guiana, will help pave the way for a mission to detect gravitational waves. LISA Pathfinder, led by the European Space Agency (ESA), is designed to test technologies that could one day detect gravitational waves. Gravitational waves, predicted by Einstein's theory of general relativity, are ripples in spacetime produced by any accelerating body. But the waves are so weak that Earth- or space-based observatories would likely only be able to directly detect such signals coming from massive astronomical systems, such as binary black holes or exploding stars. Detecting gravitational waves would be an important piece in the puzzle of how our universe began. http://photojournal.jpl.nasa.gov/catalog/PIA20196

Using Runtime Analysis to Guide Model Checking of Java Programs

NASA Technical Reports Server (NTRS)

Havelund, Klaus; Norvig, Peter (Technical Monitor)

2001-01-01

This paper describes how two runtime analysis algorithms, an existing data race detection algorithm and a new deadlock detection algorithm, have been implemented to analyze Java programs. Runtime analysis is based on the idea of executing the program once. and observing the generated run to extract various kinds of information. This information can then be used to predict whether other different runs may violate some properties of interest, in addition of course to demonstrate whether the generated run itself violates such properties. These runtime analyses can be performed stand-alone to generate a set of warnings. It is furthermore demonstrated how these warnings can be used to guide a model checker, thereby reducing the search space. The described techniques have been implemented in the b e grown Java model checker called PathFinder.

Verification of Java Programs using Symbolic Execution and Invariant Generation

NASA Technical Reports Server (NTRS)

Pasareanu, Corina; Visser, Willem

2004-01-01

Software verification is recognized as an important and difficult problem. We present a norel framework, based on symbolic execution, for the automated verification of software. The framework uses annotations in the form of method specifications an3 loop invariants. We present a novel iterative technique that uses invariant strengthening and approximation for discovering these loop invariants automatically. The technique handles different types of data (e.g. boolean and numeric constraints, dynamically allocated structures and arrays) and it allows for checking universally quantified formulas. Our framework is built on top of the Java PathFinder model checking toolset and it was used for the verification of several non-trivial Java programs.

NAS Technical Summaries, March 1993 - February 1994

NASA Technical Reports Server (NTRS)

1995-01-01

NASA created the Numerical Aerodynamic Simulation (NAS) Program in 1987 to focus resources on solving critical problems in aeroscience and related disciplines by utilizing the power of the most advanced supercomputers available. The NAS Program provides scientists with the necessary computing power to solve today's most demanding computational fluid dynamics problems and serves as a pathfinder in integrating leading-edge supercomputing technologies, thus benefitting other supercomputer centers in government and industry. The 1993-94 operational year concluded with 448 high-speed processor projects and 95 parallel projects representing NASA, the Department of Defense, other government agencies, private industry, and universities. This document provides a glimpse at some of the significant scientific results for the year.

The Twin Peaks in 3-D, as Viewed by the Mars Pathfinder IMP Camera

NASA Technical Reports Server (NTRS)

1997-01-01

The Twin Peaks are modest-size hills to the southwest of the Mars Pathfinder landing site. They were discovered on the first panoramas taken by the IMP camera on the 4th of July, 1997, and subsequently identified in Viking Orbiter images taken over 20 years ago. The peaks are approximately 30-35 meters (-100 feet) tall. North Twin is approximately 860 meters (2800 feet) from the lander, and South Twin is about a kilometer away (3300 feet). The scene includes bouldery ridges and swales or 'hummocks' of flood debris that range from a few tens of meters away from the lander to the distance of the South Twin Peak. The large rock at the right edge of the scene is nicknamed 'Hippo'. This rock is about a meter (3 feet) across and 25 meters (80 feet) distant.

This view of the Twin Peaks was produced by combining 4 individual 'Superpan' scenes from the left and right eyes of the IMP camera to cover both peaks. Each frame consists of 8 individual frames (left eye) and 7 frames (right eye) taken with different color filters that were enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution pancromatic frame that is sharper than an individual frame would be.

The anaglyph view of the Twin Peaks was produced by combining the left and right eye mosaics (above) by assigning the left eye view to the red color plane and the right eye view to the green and blue color planes (cyan), to produce a stereo anaglyph mosaic. This mosaic can be viewed in 3-D on your computer monitor or in color print form by wearing red-blue 3-D glasses.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

Indoor A* Pathfinding Through an Octree Representation of a Point Cloud

NASA Astrophysics Data System (ADS)

Rodenberg, O. B. P. M.; Verbree, E.; Zlatanova, S.

2016-10-01

There is a growing demand of 3D indoor pathfinding applications. Researched in the field of robotics during the last decades of the 20th century, these methods focussed on 2D navigation. Nowadays we would like to have the ability to help people navigate inside buildings or send a drone inside a building when this is too dangerous for people. What these examples have in common is that an object with a certain geometry needs to find an optimal collision free path between a start and goal point. This paper presents a new workflow for pathfinding through an octree representation of a point cloud. We applied the following steps: 1) the point cloud is processed so it fits best in an octree; 2) during the octree generation the interior empty nodes are filtered and further processed; 3) for each interior empty node the distance to the closest occupied node directly under it is computed; 4) a network graph is computed for all empty nodes; 5) the A* pathfinding algorithm is conducted. This workflow takes into account the connectivity for each node to all possible neighbours (face, edge and vertex and all sizes). Besides, a collision avoidance system is pre-processed in two steps: first, the clearance of each empty node is computed, and then the maximal crossing value between two empty neighbouring nodes is computed. The clearance is used to select interior empty nodes of appropriate size and the maximal crossing value is used to filter the network graph. Finally, both these datasets are used in A* pathfinding.

Pathfinder-Plus aircraft in flight

NASA Technical Reports Server (NTRS)

1998-01-01

The Pathfinder-Plus solar-powered aircraft is shown taking off from a runway, then flying at low altitude over the ocean. The vehicle, which looks like a flying ruler, operates at low airspeed. Among the missions proposed for a solar-powered aircraft are communications relay, atmospheric studies, pipeline monitoring and gas leak detection, environmental monitoring using thermal and radar images, and disaster relief and monitoring.

Sojourner Rover View of Pathfinder Lander

NASA Technical Reports Server (NTRS)

1997-01-01

Image of Pathfinder Lander on Mars taken from Sojourner Rover left front camera on sol 33. The IMP (on the lattice mast) is looking at the rover. Airbags are prominent, and the meteorology mast is shown to the right. Lowermost rock is Ender, with Hassock behind it and Yogi on the other side of the lander.

NOTE: original caption as published in Science Magazine

A Review of Solar-Powered Aircraft Flight Activity at the Pacific Missile Range Test Facility, Kauai, Hawaii

NASA Technical Reports Server (NTRS)

Ehernberger, L. J.; Donohue, Casey; Teets, Edward H., Jr.

2004-01-01

A series of solar-powered aircraft have been designed and operated by AeroVironment, Inc. (Monrovia, CA) as a part of National Aeronautics and Space Administration (NASA) objectives to develop energy-efficient high-altitude long-endurance platforms for earth observations and communications applications. Flight operations have been conducted at NASA's Dryden Flight Research Center, Edwards CA and at the U.S. Navy Pacific Missile Range Facility (PMRF) at Barking Sands, Kauai, HI. These aircraft flown at PMRF are named Pathfinder , Pathfinder Plus and Helios . Sizes of these three aircraft range from 560 lb with a 99-ft wingspan to 2300 lb with a 247-ft wingspan. Available payload capacity reaches approximately 200 lb. Pathfinder uses six engines and propellers: Pathfinder Plus 8; and Helios 14. The 2003 Helios fuel cell configurations used 10 engines and propellers. The PMRF was selected as a base of operations because if offers optimal summertime solar exposure, low prevailing wind-speeds on the runway, modest upper-air wind-speeds and the availability of suitable airspace. Between 1997 and 2001, successive altitude records of 71,530 ft, 80,200 ft, and 96,863 ft were established. Flight durations extended to 18 hours.

A Study to Compare the Failure Rates of Current Space Shuttle Ground Support Equipment with the New Pathfinder Equipment and Investigate the Effect that the Proposed GSE Infrastructure Upgrade Might Have to Reduce GSE Infrastructure Failures

NASA Technical Reports Server (NTRS)

Kennedy, Barbara J.

2004-01-01

The purposes of this study are to compare the current Space Shuttle Ground Support Equipment (GSE) infrastructure with the proposed GSE infrastructure upgrade modification. The methodology will include analyzing the first prototype installation equipment at Launch PAD B called the "Pathfinder". This study will begin by comparing the failure rate of the current components associated with the "Hardware interface module (HIM)" at the Kennedy Space Center to the failure rate of the neW Pathfinder components. Quantitative data will be gathered specifically on HIM components and the PAD B Hypergolic Fuel facility and Hypergolic Oxidizer facility areas which has the upgraded pathfinder equipment installed. The proposed upgrades include utilizing industrial controlled modules, software, and a fiber optic network. The results of this study provide evidence that there is a significant difference in the failure rates of the two studied infrastructure equipment components. There is also evidence that the support staff for each infrastructure system is not equal. A recommendation to continue with future upgrades is based on a significant reduction of failures in the new' installed ground system components.

Extreme Rock Distributions on Mars and Implications for Landing Safety

NASA Technical Reports Server (NTRS)

Golombek, M. P.

2001-01-01

Prior to the landing of Mars Pathfinder, the size-frequency distribution of rocks from the two Viking landing sites and Earth analog surfaces was used to derive a size-frequency model, for nomimal rock distributions on Mars. This work, coupled with extensive testing of the Pathfinder airbag landing system, allowed an estimate of what total rock abundances derived from thermal differencing techniques could be considered safe for landing. Predictions based on this model proved largely correct at predicting the size-frequency distribution of rocks at the Mars Pathfinder site and the fraction of potentially hazardous rocks. In this abstract, extreme rock distributions observed in Mars Orbiter Camera (MOC) images are compared with those observed at the three landing sites and model distributions as an additional constraint on potentially hazardous surfaces on Mars.

Marie Curie during ORT4

NASA Technical Reports Server (NTRS)

2003-01-01

Marie Curie rover drives down the rear ramp during Operational Readiness Test (ORT) 4.

Pathfinder, a low-cost Discovery mission, is the first of a new fleet of spacecraft that are planned to explore Mars over thenext ten years. Mars Global Surveyor, already en route, arrives at Mars on September 11 to begin a two year orbital reconnaissance of the planet's composition, topography, and climate. Additional orbiters and landers will follow every 26 months.

The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

JAVA PathFinder

NASA Technical Reports Server (NTRS)

Mehhtz, Peter

2005-01-01

JPF is an explicit state software model checker for Java bytecode. Today, JPF is a swiss army knife for all sort of runtime based verification purposes. This basically means JPF is a Java virtual machine that executes your program not just once (like a normal VM), but theoretically in all possible ways, checking for property violations like deadlocks or unhandled exceptions along all potential execution paths. If it finds an error, JPF reports the whole execution that leads to it. Unlike a normal debugger, JPF keeps track of every step how it got to the defect.

SRB Processing Facilities Media Event

NASA Image and Video Library

2016-03-01

At the Rotation, Processing and Surge Facility (RPSF) at NASA’s Kennedy Space Center in Florida, members of the news media photograph the process as cranes are used to lift one of two pathfinders, or test versions, of solid rocket booster segments for NASA’s Space Launch System rocket. The Ground Systems Development and Operations Program and Jacobs Engineering, on the Test and Operations Support Contract, are preparing the booster segments, which are inert, for a series of lifts, moves and stacking operations to prepare for Exploration Mission-1, deep-space missions and the journey to Mars.

SRB Processing Facilities Media Event

NASA Image and Video Library

2016-03-01

At the Rotation, Processing and Surge Facility (RPSF) at NASA’s Kennedy Space Center in Florida, members of the news media watch as cranes are used to lift one of two pathfinders, or test versions, of solid rocket booster segments for NASA’s Space Launch System rocket. The Ground Systems Development and Operations Program and Jacobs Engineering, on the Test and Operations Support Contract, are preparing the booster segments, which are inert, for a series of lifts, moves and stacking operations to prepare for Exploration Mission-1, deep-space missions and the journey to Mars.

Development and testing of laser-induced breakdown spectroscopy for the Mars Rover Program : elemental analysis at stand-off distances

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

Cremers, D. A.; Wiens, R. C.; Arp, Z. A.

2003-01-01

One of the most Fundamental pieces of information about any planetary body is the elemental cornposition of its surface materials. The Viking Martian landers employed XRF (x-ray fluorescence) and the MER rovers are carrying APXS (alpha-proton x-ray spectrometer) instruments upgraded from that used on the Pathfinder rover to supply elemental composition information for soils and rocks for which direct contact is possible. These in-situ analyses require that the lander or rover be in contact with the sample

Cryogenic Test Technology 1984.

DTIC Science & Technology

1985-04-01

requirements. The material selection for the Pathfinder I was further restricted by long delivery times before Nitronic 40 was chosen. The alloys under...severe requirements of cryogenic model building. A detailed study of the characteristics of Nitronic 40 is reported in reference 36. This paper, and...remarks elsewhere about experience with Pathfinder I (made from Nitronic 40 ), suggest that quality control problems were encountered with at least one batch

JPL Experience with the Mars Pathfinder, Mission Simulation Battery

NASA Technical Reports Server (NTRS)

Perrone, Dave; Ewell, Richard

1997-01-01

A summary of the Mars Pathfinder Battery is given. The battery survived 47 days at 25 deg. C; it survived a 7 month stand at 10 to -5 deg. C; it met and exceeded 40 ampere-hour capacity for EDL; it met the 30 cycle minimum for Mars surface operation; and the project power profile for MArs surface operation does not yield energy balance.

Canadian Hydrogen Intensity Mapping Experiment (CHIME) pathfinder

NASA Astrophysics Data System (ADS)

Bandura, Kevin; Addison, Graeme E.; Amiri, Mandana; Bond, J. Richard; Campbell-Wilson, Duncan; Connor, Liam; Cliche, Jean-François; Davis, Greg; Deng, Meiling; Denman, Nolan; Dobbs, Matt; Fandino, Mateus; Gibbs, Kenneth; Gilbert, Adam; Halpern, Mark; Hanna, David; Hincks, Adam D.; Hinshaw, Gary; Höfer, Carolin; Klages, Peter; Landecker, Tom L.; Masui, Kiyoshi; Mena Parra, Juan; Newburgh, Laura B.; Pen, Ue-li; Peterson, Jeffrey B.; Recnik, Andre; Shaw, J. Richard; Sigurdson, Kris; Sitwell, Mike; Smecher, Graeme; Smegal, Rick; Vanderlinde, Keith; Wiebe, Don

2014-07-01

A pathfinder version of CHIME (the Canadian Hydrogen Intensity Mapping Experiment) is currently being commissioned at the Dominion Radio Astrophysical Observatory (DRAO) in Penticton, BC. The instrument is a hybrid cylindrical interferometer designed to measure the large scale neutral hydrogen power spectrum across the redshift range 0.8 to 2.5. The power spectrum will be used to measure the baryon acoustic oscillation (BAO) scale across this poorly probed redshift range where dark energy becomes a significant contributor to the evolution of the Universe. The instrument revives the cylinder design in radio astronomy with a wide field survey as a primary goal. Modern low-noise amplifiers and digital processing remove the necessity for the analog beam forming that characterized previous designs. The Pathfinder consists of two cylinders 37m long by 20m wide oriented north-south for a total collecting area of 1,500 square meters. The cylinders are stationary with no moving parts, and form a transit instrument with an instantaneous field of view of ~100 degrees by 1-2 degrees. Each CHIME Pathfinder cylinder has a feedline with 64 dual polarization feeds placed every ~30 cm which Nyquist sample the north-south sky over much of the frequency band. The signals from each dual-polarization feed are independently amplified, filtered to 400-800 MHz, and directly sampled at 800 MSps using 8 bits. The correlator is an FX design, where the Fourier transform channelization is performed in FPGAs, which are interfaced to a set of GPUs that compute the correlation matrix. The CHIME Pathfinder is a 1/10th scale prototype version of CHIME and is designed to detect the BAO feature and constrain the distance-redshift relation. The lessons learned from its implementation will be used to inform and improve the final CHIME design.

Testing Planetary Rovers: Technologies, Perspectives, and Lessons Learned

NASA Technical Reports Server (NTRS)

Thomas, Hans; Lau, Sonie (Technical Monitor)

1998-01-01

Rovers are a vital component of NASA's strategy for manned and unmanned exploration of space. For the past five years, the Intelligent Mechanisms Group at the NASA Ames Research Center has conducted a vigorous program of field testing of rovers from both technology and science team productivity perspective. In this talk, I will give an overview of the the last two years of the test program, focusing on tests conducted in the Painted Desert of Arizona, the Atacama desert in Chile, and on IMG participation in the Mars Pathfinder mission. An overview of autonomy, manipulation, and user interface technologies developed in response to these missions will be presented, and lesson's learned in these missions and their impact on future flight missions will be presented. I will close with some perspectives on how the testing program has affected current rover systems.

Color Mosaic of Rover & Terrain

NASA Image and Video Library

1997-07-05

NASA's Sojourner rover and undeployed ramps onboard the Mars Pathfinder spacecraft can be seen in this image, by the Imager for Mars Pathfinder (IMP) on July 4 (Sol 1). This image has been corrected for the curvature created by parallax. The microrover Sojourner is latched to the petal, and has not yet been deployed. The ramps are a pair of deployable metal reels which will provide a track for the rover as it slowly rolls off the lander, over the spacecraft's deflated airbags, and onto the surface of Mars. Pathfinder scientists will use this image to determine whether it is safe to deploy the ramps. One or both of the ramps will be unfurled, and then scientists will decide whether the rover will use either the forward or backward ramp for its descent. http://photojournal.jpl.nasa.gov/catalog/PIA00621

Marie Curie during ORT6

NASA Technical Reports Server (NTRS)

2003-01-01

Marie Curie sits on the lander petal prior to deployment during the pre launch Operations Readiness Test (ORT) 6.

Pathfinder, a low-cost Discovery mission, is the first of a new fleet of spacecraft that are planned to explore Mars over thenext ten years. Mars Global Surveyor, already en route, arrives at Mars on September 11 to begin a two year orbital reconnaissance of the planet's composition, topography, and climate. Additional orbiters and landers will follow every 26 months.

The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

DSMC Simulations of Blunt Body Flows for Mars Entries: Mars Pathfinder and Mars Microprobe Capsules

NASA Technical Reports Server (NTRS)

Moss, James N.; Wilmoth, Richard G.; Price, Joseph M.

1997-01-01

The hypersonic transitional flow aerodynamics of the Mars Pathfinder and Mars Microprobe capsules are simulated with the direct simulation Monte Carlo method. Calculations of axial, normal, and static pitching coefficients were obtained over an angle of attack range comparable to actual flight requirements. Comparisons are made with modified Newtonian and free-molecular-flow calculations. Aerothermal results were also obtained for zero incidence entry conditions.

Measuring Pilot Knowledge in Training: The Pathfinder Network Scaling Technique

DTIC Science & Technology

2007-01-01

Network Scaling Technique Leah J. Rowe Roger W. Schvaneveldt L -3 Communications Arizona State University Mesa, AZ Mesa, AZ leah.rowe...7293 Page 2 of 8 Measuring Pilot Knowledge in Training: The Pathfinder Network Scaling Technique Leah J. Rowe Roger W. Schvaneveldt L -3...training. ABOUT THE AUTHORS Leah J. Rowe is a Training Research Specialist with L -3 Communications at the Air Force Research Laboratory

Reconsidering the Theological and Ethical Implications of Extraterrestrial Life

NASA Technical Reports Server (NTRS)

Randolph, Richard O. (Editor); Race, Margaret S.; McKay, Christopher P. (Editor)

1997-01-01

As we stand on the threshold of a new millennium, we also find ourselves at the brink of a new and exciting era in space exploration. In fact, this new era has already begun, with the successful landing and exploration of Mars by the Pathfinder mission in July 1997. Pathfinder represents an important scientific accomplishment for NASA because it demonstrated the agency's ability to successfully explore space at a relatively modest price. At the same time, Pathfinder revealed once again the genuine interest and fascination that people all over planet Earth have for space exploration. The Pathfinder mission is just one of several recent events-both scientific and cultural-that reveal this deep and almost unquenchable curiosity about space-and the possibility that there is life "out there." In August 1996, the public was captivated with NASA's announcement that a meteorite from Mars may contain evidence of early microscopic life. Shortly after the NASA announcement, media coverage of the discovery-and public discourse concerning the discovery-turned to an examination of the theological implications of evidence for extraterrestrial, albeit unintelligent, life. To a lesser extent, public reaction to the Hale-Bopp comet in the Spring of 1996 is also suggestive of many persons' deep passion to know more about space.

The Integration and Test Program of the James Webb Space Telescope

NASA Technical Reports Server (NTRS)

Kimble, Randy

2012-01-01

The James Webb Space Telescope (JWST) project has entered into a comprehensive integration and test (I&T) program that over the coming years will assemble the various elements of the observatory (the Optical Telescope Element [OTE], the Integrated Science Instrument Module [ISIM], and the Spacecraft) and verify the readiness of the integrated system for launch. The I&T program as replanned for a 2018 launch readiness date has a number of interesting features. These include a streamlined ISIM cryo-vacuum test program at Goddard Space Flight Center, a streamlined OTIS (OTE + ISIM) test program at Johnson Space Center (JSC), the addition of a second Core cryo-vacuum thermal test, the enhancement of the Pathfinder program at JSC, and enhancement of the subsystem-level testing program for the MIRI cryo-cooler. These latter activities all serve to reduce the risk heading into the end-to-end optical and thermal testing of the telescope at JSC, leading to reduced cost and schedule risk for that critical activity. We report here on the overall I&T program for JWST and on the status of the hardware and plans that support it.

Generalized Symbolic Execution for Model Checking and Testing

NASA Technical Reports Server (NTRS)

Khurshid, Sarfraz; Pasareanu, Corina; Visser, Willem; Kofmeyer, David (Technical Monitor)

2003-01-01

Modern software systems, which often are concurrent and manipulate complex data structures must be extremely reliable. We present a novel framework based on symbolic execution, for automated checking of such systems. We provide a two-fold generalization of traditional symbolic execution based approaches: one, we define a program instrumentation, which enables standard model checkers to perform symbolic execution; two, we give a novel symbolic execution algorithm that handles dynamically allocated structures (e.g., lists and trees), method preconditions (e.g., acyclicity of lists), data (e.g., integers and strings) and concurrency. The program instrumentation enables a model checker to automatically explore program heap configurations (using a systematic treatment of aliasing) and manipulate logical formulae on program data values (using a decision procedure). We illustrate two applications of our framework: checking correctness of multi-threaded programs that take inputs from unbounded domains with complex structure and generation of non-isomorphic test inputs that satisfy a testing criterion. Our implementation for Java uses the Java PathFinder model checker.

Mars Pathfinder [foldout].

PubMed

1997-12-05

The following foldout present images and analysis from the Mars Pathfinder Mission that are discussed in seven subsequent Reports. The center is a four-page panorama of the surface of Mars around the lander (Plate 1). The back of the foldout contains surface images (Plate 7), a different perspective of the landing site (Plate 2), rover targets (Plate 3), locations of rocks and other features (Plate 6) and data analysis (Plates 4, 4, 8, 9, and 10).

Mars Pathfinder Project: Planetary Constants and Models

NASA Technical Reports Server (NTRS)

Vaughan, Robin

1995-01-01

This document provides a common set of astrodynamic constants and planetary models for use by the Mars Pathfinder Project. It attempts to collect in a single reference all the quantities and models in use across the project during development and for mission operations. These models are central to the navigation and mission design functions, but they are also used in other aspects of the project such as science observation planning and data reduction.

LISA Pathfinder first results

NASA Astrophysics Data System (ADS)

Vetrugno, D.

LISA Pathfinder (LPF) is an in-flight technological demonstrator designed and launched to prove the feasibility of sub-femto-g free fall of kilo-sized test masses (TM), an essential ingredient for the future gravitational wave observatory from space. Half a year after launch, the first results are available and show an incredibly well-performing instrument. The results represent a first and important step towards the long awaited construction and launch of LISA, the Laser Interferometer Space Antenna.

Mechanosensing is critical for axon growth in the developing brain

PubMed Central

Pillai, Eva K.; Sheridan, Graham K.; Svoboda, Hanno; Viana, Matheus; da F. Costa, Luciano; Guck, Jochen; Holt, Christine E.; Franze, Kristian

2016-01-01

During nervous system development, neurons extend axons along well-defined pathways. The current understanding of axon pathfinding is based mainly on chemical signalling. However, growing neurons interact not only chemically but also mechanically with their environment. Here we identify mechanical signals as important regulators of axon pathfinding. In vitro, substrate stiffness determined growth patterns of Xenopus retinal ganglion cell (RGC) axons. In vivo atomic force microscopy revealed striking stiffness gradient patterns in the embryonic brain. RGC axons grew towards the tissue’s softer side, which was reproduced in vitro in the absence of chemical gradients. To test the importance of mechanical signals for axon growth in vivo, we altered brain stiffness, blocked mechanotransduction pharmacologically, and knocked down the mechanosensitive ion channel Piezo1. All treatments resulted in aberrant axonal growth and pathfinding errors, suggesting that local tissue stiffness–read out by mechanosensitive ion channels–is critically involved in instructing neuronal growth in vivo. PMID:27643431

VR for Mars Pathfinder

NASA Technical Reports Server (NTRS)

Blackmon, Theodore

1998-01-01

Virtual reality (VR) technology has played an integral role for Mars Pathfinder mission, operations Using an automated machine vision algorithm, the 3d topography of the Martian surface was rapidly recovered fro -a the stereo images captured. by the Tender camera to produce photo-realistic 3d models, An advanced, interface was developed for visualization and interaction with. the virtual environment of the Pathfinder landing site for mission scientists at the Space Flight Operations Facility of the Jet Propulsion Laboratory. The VR aspect of the display allowed mission scientists to navigate on Mars in Bud while remaining here on Earth, thus improving their spatial awareness of the rock field that surrounds the lenders Measurements of positions, distances and angles could be easily extracted from the topographic models, providing valuable information for science analysis and mission. planning. Moreover, the VR map of Mars has also been used to assist with the archiving and planning of activities for the Sojourner rover.

The Development of a Novel High Throughput Computational Tool for Studying Individual and Collective Cellular Migration

PubMed Central

Chapnick, Douglas A.; Jacobsen, Jeremy; Liu, Xuedong

2013-01-01

Understanding how cells migrate individually and collectively during development and cancer metastasis can be significantly aided by a computation tool to accurately measure not only cellular migration speed, but also migration direction and changes in migration direction in a temporal and spatial manner. We have developed such a tool for cell migration researchers, named Pathfinder, which is capable of simultaneously measuring the migration speed, migration direction, and changes in migration directions of thousands of cells both instantaneously and over long periods of time from fluorescence microscopy data. Additionally, we demonstrate how the Pathfinder software can be used to quantify collective cell migration. The novel capability of the Pathfinder software to measure the changes in migration direction of large populations of cells in a spatiotemporal manner will aid cellular migration research by providing a robust method for determining the mechanisms of cellular guidance during individual and collective cell migration. PMID:24386097

The LISA Pathfinder Mission: Sub-picometer Interferometry in Space

NASA Astrophysics Data System (ADS)

Slutsky, Jacob; LISA Pathfinder Collaboration

2018-01-01

The European Space Agency’s LISA Pathfinder was a mission built to demonstrate the technologies essential to implement a space-based gravitational wave observatory sensitive in the milli-Hertz frequency band. ESA recently selected the LISA mission as such a future observatory, scheduled to launch in the early 2030s. LISA Pathfinder launched in late 2015 and concluded its final extended mission in July 2017, during which time it placed the two test masses into free fall and successfully measured the relative acceleration between them to a sensitivity that validates a number of critical technologies for LISA. These include drag-free control of the test masses, low noise microNewton thrusters to control the spacecraft, and sub-picometer-level laser metrology in space. The mission also served as a sensitive probe of the environmenal conditions in which LISA will operate. This poster summarizes the recent analysis results, with an eye towards the implications for the LISA mission.

Rover Touchdown on Martian Surface

NASA Image and Video Library

1997-07-06

This picture taken by the IMP (Imager for Mars Pathfinder) aboard the Mars Pathfinder spacecraft depicts the rover Sojourner's position after driving onto the Martian surface. Sojourner has become the first autonomous robot ever to traverse the surface of Mars. This image reflects the success of Pathfinder's principle objective -- to place a payload on Mars in a safe, operational configuration. The primary mission of Sojourner, scheduled to last seven days, will be to use its Alpha Proton X-ray Spectrometer (APXS) instrument to determine the elements that make up the rocks and soil on Mars. A full study using the APXS takes approximately ten hours, and can measure all elements except hydrogen at any time of the Martian day or night. The APXS will conduct its studies by bombarding rocks and soil samples with alpha particle radiation -- charged particles equivalent to the nucleus of a helium atom, consisting of two protons and two neutrons. http://photojournal.jpl.nasa.gov/catalog/PIA00623

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

Wass, P. J.; Araujo, H.; Sumner, T.

We present the concept, design and testing of the radiation monitor for LISA Pathfinder. Galactic cosmic rays (GCRs) and solar energetic particles (SEPs) will cause charging of the LISA Pathfinder test masses producing unwanted disturbances which could be significant during a large solar eruption. A radiation monitor on board LISA Pathfinder, using silicon PIN diodes as particle detectors, will measure the particle flux responsible for charging. It will also be able to record spectral information to identify solar energetic particle events. The design of the monitor was supported by Monte Carlo simulations which allow detailed predictions of the radiation monitormore » performance. We present these predictions as well as the results of high-energy proton tests carried out at the Paul Scherrer Institute, Switzerland. The tests show good agreement with our simulations and confirm the capability of the radiation monitor to perform well in the space environment, meeting all science requirements.« less

Trio combines with dock to regulate Pak activity during photoreceptor axon pathfinding in Drosophila.

PubMed

Newsome, T P; Schmidt, S; Dietzl, G; Keleman, K; Asling, B; Debant, A; Dickson, B J

2000-04-28

Correct pathfinding by Drosophila photoreceptor axons requires recruitment of p21-activated kinase (Pak) to the membrane by the SH2-SH3 adaptor Dock. Here, we identify the guanine nucleotide exchange factor (GEF) Trio as another essential component in photoreceptor axon guidance. Regulated exchange activity of one of the two Trio GEF domains is critical for accurate pathfinding. This GEF domain activates Rac, which in turn activates Pak. Mutations in trio result in projection defects similar to those observed in both Pak and dock mutants, and trio interacts genetically with Rac, Pak, and dock. These data define a signaling pathway from Trio to Rac to Pak that links guidance receptors to the growth cone cytoskeleton. We propose that distinct signals transduced via Trio and Dock act combinatorially to activate Pak in spatially restricted domains within the growth cone, thereby controlling the direction of axon extension.

Occurrence of nonspecific reactions among stool specimens tested by the Abbott TestPack rotavirus enzyme immunoassay.

PubMed Central

Lipson, S M; Leonardi, G P; Salo, R J; Schutzbank, T E; Kaplan, M H

1990-01-01

Sixty-five stool specimens obtained from children suffering from gastroenteritis were tested for the presence of antigen to rotavirus by the Abbott TestPack Rotavirus (TestPack) enzyme immunoassay kit. The Kallestad Pathfinder enzyme immunoassay, polyacrylamide gel electrophoresis, immune electron microscopy, and virus isolation were utilized as reference assays. Fifty-four specimens were in accord by TestPack and Kallestad Pathfinder. Among 11 discordant specimens positive with TestPack but negative by Kallestad Pathfinder, rotavirus was not identified by polyacrylamide gel electrophoresis, immune electron microscopy, or isolation in primary African green monkey kidney cell cultures. TestPack displayed a performance specificity of 83%. The inordinately high number of stool specimens reported as false-positive by TestPack precludes the incorporation of this antigen detection kit into our routine regimen of diagnostic virologic testing. Images PMID:2166074

Validation of Interannual Differences of AIRS Monthly Mean Parameters

NASA Technical Reports Server (NTRS)

Susskind, Joel; Iredell, Lena; Keita, Fricky; Molnar, Gyula

2005-01-01

Monthly mean fields of select geophysical parameters derived from analysis of AIRS/AMSU data, and their interannual differences, are shown and compared with analogous fields derived from other sources. All AIRS fields are derived using the AIRS Science Team Version 4 algorithm. Monthly mean results are shown for January 2004, as are interannual differences between January 2004 and January 2003. AIRS temperature and water vapor profile fields are compared with monthly mean collocated ECMWF 3 hour forecast and monthly mean TOVS Pathfinder Path A data. AIRS Tropospheric and Stratospheric coarse climate indicators are compared with analogous MSU products derived by Spencer and christy and found in the TOVS Pathfinder Path A data set. Total ozone is compared with results produced by TOMS. OLR is compared with OLR derived using CERES data and found in the TOVS Pathfinder Path A data set. AIRS results agree well in all cases, especially in the interannual difference sense.

Big Crater as Viewed by Pathfinder Lander

NASA Technical Reports Server (NTRS)

1997-01-01

The 'Big Crater' is actually a relatively small Martian crater to the southeast of the Mars Pathfinder landing site. It is 1500 meters (4900 feet) in diameter, or about the same size as Meteor Crater in Arizona. Superimposed on the rim of Big Crater (the central part of the rim as seen here) is a smaller crater nicknamed 'Rimshot Crater.' The distance to this smaller crater, and the nearest portion of the rim of Big Crater, is 2200 meters (7200 feet). To the right of Big Crater, south from the spacecraft, almost lost in the atmospheric dust 'haze,' is the large streamlined mountain nicknamed 'Far Knob.' This mountain is over 450 meters (1480 feet) tall, and is over 30 kilometers (19 miles) from the spacecraft. Another, smaller and closer knob, nicknamed 'Southeast Knob' can be seen as a triangular peak to the left of the flanks of the Big Crater rim. This knob is 21 kilometers (13 miles) southeast from the spacecraft.

The larger features visible in this scene - Big Crater, Far Knob, and Southeast Knob - were discovered on the first panoramas taken by the IMP camera on the 4th of July, 1997, and subsequently identified in Viking Orbiter images taken over 20 years ago. The scene includes rocky ridges and swales or 'hummocks' of flood debris that range from a few tens of meters away from the lander to the distance of South Twin Peak. The largest rock in the nearfield, just left of center in the foreground, nicknamed 'Otter', is about 1.5 meters (4.9 feet) long and 10 meters (33 feet) from the spacecraft.

This view of Big Crater was produced by combining 6 individual 'Superpan' scenes from the left and right eyes of the IMP camera. Each frame consists of 8 individual frames (left eye) and 7 frames (right eye) taken with different color filters that were enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution panchromatic frame that is sharper than an individual frame would be.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

SRB Processing Facilities Media Event

NASA Image and Video Library

2016-03-01

Members of the news media watch as a crane is used to move one of two pathfinders, or test versions, of solid rocket booster segments for NASA’s Space Launch System rocket to a test stand in the Rotation, Processing and Surge Facility at NASA’s Kennedy Space Center in Florida. Inside the RPSF, the Ground Systems Development and Operations Program and Jacobs Engineering, on the Test and Operations Support Contract, will prepare the booster segments, which are inert, for a series of lifts, moves and stacking operations to prepare for Exploration Mission-1, deep-space missions and the journey to Mars.

NAS: The first year

NASA Technical Reports Server (NTRS)

Bailey, F. R.; Kutler, Paul

1988-01-01

Discussed are the capabilities of NASA's Numerical Aerodynamic Simulation (NAS) Program and its application as an advanced supercomputing system for computational fluid dynamics (CFD) research. First, the paper describes the NAS computational system, called the NAS Processing System Network, and the advanced computational capabilities it offers as a consequence of carrying out the NAS pathfinder objective. Second, it presents examples of pioneering CFD research accomplished during NAS's first operational year. Examples are included which illustrate CFD applications for predicting fluid phenomena, complementing and supplementing experimentation, and aiding in design. Finally, pacing elements and future directions for CFD and NAS are discussed.

Precise and Scalable Static Program Analysis of NASA Flight Software

NASA Technical Reports Server (NTRS)

Brat, G.; Venet, A.

2005-01-01

Recent NASA mission failures (e.g., Mars Polar Lander and Mars Orbiter) illustrate the importance of having an efficient verification and validation process for such systems. One software error, as simple as it may be, can cause the loss of an expensive mission, or lead to budget overruns and crunched schedules. Unfortunately, traditional verification methods cannot guarantee the absence of errors in software systems. Therefore, we have developed the CGS static program analysis tool, which can exhaustively analyze large C programs. CGS analyzes the source code and identifies statements in which arrays are accessed out of bounds, or, pointers are used outside the memory region they should address. This paper gives a high-level description of CGS and its theoretical foundations. It also reports on the use of CGS on real NASA software systems used in Mars missions (from Mars PathFinder to Mars Exploration Rover) and on the International Space Station.

Teaching, Learning, and Planetary Exploration

NASA Technical Reports Server (NTRS)

Brown, Robert A.

2002-01-01

This is the final report of a program that examined the fundamentals of education associated with space activities, promoted educational policy development in appropriate forums, and developed pathfinder products and services to demonstrate the utility of advanced communication technologies for space-based education. Our focus was on space astrophysics and planetary exploration, with a special emphasis on the themes of the Origins Program, with which the Principal Investigator (PI) had been involved from the outset. Teaching, Learning, and Planetary Exploration was also the core funding of the Space Telescope Science Institute's (ST ScI) Special Studies Office (SSO), and as such had provided basic support for such important NASA studies as the fix for Hubble Space Telescope (HST) spherical aberration, scientific conception of the HST Advanced Camera, specification of the Next-Generation Space Telescope (NGST), and the strategic plan for the second decade of the HST science program.

Software Reuse in the Planetary Context: The JPL/MIPL Mars Program Suite

NASA Technical Reports Server (NTRS)

Deen, Robert

2012-01-01

Reuse greatly reduces development costs. Savings can be invested in new/improved capabilities Or returned to sponsor Worth the extra time to "do it right" Operator training greatly reduced. MIPL MER personnel can step into MSL easily because the programs are familiar. Application programs much easier to write. Can assume core capabilities exist already. Multimission Instrument (Image) Processing Lab at MIPL Responsible for the ground-based instrument data processing for (among other things) all recent in-situ Mars missions: Mars Pathfinder Mars Polar Lander (MPL) Mars Exploration Rovers (MER) Phoenix Mars Science Lab (MSL) Responsibilities for in-situ missions Reconstruction of instrument data from telemetry Systematic creation of Reduced Data Records (RDRs) for images Creation of special products for operations, science, and public outreach In the critical path for operations MIPL products required for planning the next Sol s activities

Characterization of the Martian surface deposits by the Mars Pathfinder rover, Sojourner.

NASA Astrophysics Data System (ADS)

Matijevic, J. R.; Crisp, J.; Bickler, D. B.; Banes, R. S.; Cooper, B. K.; Eisen, H. J.; Gensler, J.; Haldemann, A.; Hartman, F.; Jewett, K. A.; Matthies, L. H.; Laubach, S. L.; Mishkin, A. H.; Morrison, J. C.; Nguyen, T. T.; Sirota, A. R.; Stone, H. W.; Stride, S.; Sword, L. F.; Tarsala, J. A.; Thompson, A. D.; Wallace, M. T.; Welch, R.; Wellman, E.; Wilcox, B. H.; Ferguson, D.; Jenkins, P.; Kolecki, J.; Landis, G. A.; Wilt, D.; Rover Team

1997-12-01

The Mars Pathfinder rover discovered pebbles on the surface and in rocks that may be sedimentary - not volcanic - in origin. Surface pebbles may have been rounded by Ares flood waters or liberated by weathering of sedimentary rocks called conglomerates. Conglomerates imply that water existed elsewhere and earlier than the Ares flood. Most soil-like deposits are similar to moderately dense soils on Earth. Small amounts of dust are currently settling from the atmosphere.

Pathfinder Sea Surface Temperature Climate Data Record

NASA Astrophysics Data System (ADS)

Baker-Yeboah, S.; Saha, K.; Zhang, D.; Casey, K. S.

2016-02-01

Global sea surface temperature (SST) fields are important in understanding ocean and climate variability. The NOAA National Centers for Environmental Information (NCEI) develops and maintains a high resolution, long-term, climate data record (CDR) of global satellite SST. These SST values are generated at approximately 4 km resolution using Advanced Very High Resolution Radiometer (AVHRR) instruments aboard NOAA polar-orbiting satellites going back to 1981. The Pathfinder SST algorithm is based on the Non-Linear SST algorithm using the modernized NASA SeaWiFS Data Analysis System (SeaDAS). Coefficients for this SST product were generated using regression analyses with co-located in situ and satellite measurements. Previous versions of Pathfinder included level 3 collated (L3C) products. Pathfinder Version 5.3 includes level 2 pre-processed (L2P), level 3 Uncollated (L3C), and L3C products. Notably, the data were processed in the cloud using Amazon Web Services and are made available through all of the modern web visualization and subset services provided by the THREDDS Data Server, the Live Access Server, and the OPeNDAP Hyrax Server.In this version of Pathfinder SST, anomalous hot-spots at land-water boundaries are better identified and the dataset includes updated land masks and sea ice data over the Antarctic ice shelves. All quality levels of SST values are generated, giving the user greater flexibility and the option to apply their own cloud-masking procedures. Additional improvements include consistent cloud tree tests for NOAA-07 and NOAA-19 with respect to the other sensors, improved SSTs in sun glint areas, and netCDF file format improvements to ensure consistency with the latest Group for High Resolution SST (GHRSST) requirements. This quality controlled satellite SST field is a reference environmental data record utilized as a primary resource of SST for numerous regional and global marine efforts.

A design pathfinder with material correlation points for inflatable systems

NASA Astrophysics Data System (ADS)

Fulcher, Jared Terrell

The incorporation of inflatable structures into aerospace systems can produce significant advantages in stowed volume to mechanical effectiveness and overall weight. Many applications of these ultra-lightweight systems are designed to precisely control internal or external surfaces, or both, to achieve desired performance. The modeling of these structures becomes complex due to the material nonlinearities inherent to the majority of construction materials used in inflatable structures. Furthermore, accurately modeling the response and behavior of the interfacing boundaries that are common to many inflatable systems will lead to better understanding of the entire class of structures. The research presented involved using nonlinear finite element simulations correlated with photogrammetry testing to develop a procedure for defining material properties for commercially available polyurethane-coated woven nylon fabric, which is representative of coated materials that have been proven materials for use in many inflatable systems. Further, the new material model was used to design and develop an inflatable pathfinder system which employs only internal pressure to control an assembly of internal membranes. This canonical inflatable system will be used for exploration and development of general understanding of efficient design methodology and analysis of future systems. Canonical structures are incorporated into the design of the phased pathfinder system to allow for more universal insight. Nonlinear finite element simulations were performed to evaluate the effect of various boundary conditions, loading configurations, and material orientations on the geometric precision of geometries representing typical internal/external surfaces commonly incorporated into inflatable pathfinder system. The response of the inflatable system to possible damage was also studied using nonlinear finite element simulations. Development of a correlated material model for analysis of the inflatable pathfinder system has improved the efficiency of design and analysis techniques of future inflatable structures. KEYWORDS: Nonlinear Finite Element, Inflatable Structures, Gossamer Space Systems, Photogrammetry Measurements, Coated Woven Fabric.

NASA Discovery Program Workshop

NASA Technical Reports Server (NTRS)

1992-01-01

The purpose of the workshop was to review concepts for Discover-class missions that would follow the first two missions (MESUR-Pathfinder and NEAR) of this new program. The concepts had been generated by scientists involved in NASA's Solar System Exploration Program to carry out scientifically important investigations within strict guidelines -- $150 million cap on development cost and 3 year cap on development schedule. Like the Astrophysics Small Explorers (SMEX), such 'faster and cheaper' missions could provide vitality to solar system exploration research by returning high quality data more frequently and regularly and by involving many more young researchers than normally participate directly in larger missions. An announcement of opportunity (AO) to propose a Discovery mission to NASA is expected to be released in about two years time. One purpose of the workshop was to assist Code SL in deciding how to allocate its advanced programs resources. A second, complimentary purpose was to provide the concept proposers with feedback to allow them to better prepare for the AO.

Pathfinder. Volume 9, Number 3, May/June 2011

DTIC Science & Technology

2011-05-01

Pathfinder magazine .” Any reproduction of graphics, photographs and imagery is subject to the original copyright. 2 On My Mind 5 NGA in the News ›› F E A...team analyst stationed in Baghdad to search for and identify advertising billboards in Baghdad, a large and mundane task. To a CA commander, however...unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 On My Mind Putting the Power of GEOINT in the Warfighter’s Hands As a

Demonstration of a Large-Scale Tank Assembly Via Circumferential Friction Stir Welds

NASA Technical Reports Server (NTRS)

Jones, Chip; Adams, Glynn; Colligan, Kevin; McCool, A. (Technical Monitor)

2000-01-01

Five (5) each 14-foot diameter circumferential FSWelds were conducted on the modified CWT, two (2) each pathfinder and three (3) each assembly welds Tapered circumferential welds were successfully demonstrated The use of a closeout anvil was successfully demonstrated during one of the pathfinder welds Considerable difficulty maintaining joint f it-up during the weld process Anvil deflections Hardware dimensional tolerances Inadequate clamping Variations in the heat sink characteristics of the circumferential anvil as compared to the test panel anvil

Integrated Docking Simulation and Testing with the Johnson Space Center Six-Degree of Freedom Dynamic Test System

NASA Technical Reports Server (NTRS)

Mitchell, Jennifer D.; Cryan, Scott P.; Baker, Kenneth; Martin, Toby; Goode, Robert; Key, Kevin W.; Manning, Thomas; Chien, Chiun-Hong

2008-01-01

The Exploration Systems Architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in Low Earth Orbit (LEO) and in Low Lunar Orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as Automated Rendezvous and Docking, AR&D). The crewed versions may also perform AR&D, possibly with a different level of automation and/or autonomy, and must also provide the crew with relative navigation information for manual piloting. The capabilities of the RPOD sensors are critical to the success of the Constellation Program; this is carried as one of the CEV Project top risks. The Exploration Technology Development Program (ETDP) AR&D Sensor Technology Project seeks to reduce this risk by increasing technology maturation of selected relative navigation sensor technologies through testing and simulation. One of the project activities is a series of "pathfinder" testing and simulation activities to integrate relative navigation sensors with the Johnson Space Center Six-Degree-of-Freedom Test System (SDTS). The SDTS will be the primary testing location for the Orion spacecraft s Low Impact Docking System (LIDS). Project team members have integrated the Orion simulation with the SDTS computer system so that real-time closed loop testing can be performed with relative navigation sensors and the docking system in the loop during docking and undocking scenarios. Two relative navigation sensors are being used as part of a "pathfinder" activity in order to pave the way for future testing with the actual Orion sensors. This paper describes the test configuration and test results.

James Webb Space Telescope in NASA's giant thermal vacuum chamber

NASA Image and Video Library

2015-04-20

Inside NASA's giant thermal vacuum chamber, called Chamber A, at NASA's Johnson Space Center in Houston, the James Webb Space Telescope's Pathfinder backplane test model, is being prepared for its cryogenic test. Previously used for manned spaceflight missions, this historic chamber is now filled with engineers and technicians preparing for a crucial test. Exelis developed and installed the optical test equipment in the chamber. "The optical test equipment was developed and installed in the chamber by Exelis," said Thomas Scorse, Exelis JWST Program Manager. "The Pathfinder telescope gives us our first opportunity for an end-to-end checkout of our equipment." "This will be the first time on the program that we will be aligning two primary mirror segments together," said Lee Feinberg, NASA Optical Telescope Element Manager. "In the past, we have always tested one mirror at a time but this time we will use a single test system and align both mirrors to it as though they are a single monolithic mirror." The James Webb Space Telescope is the scientific successor to NASA's Hubble Space Telescope. It will be the most powerful space telescope ever built. Webb is an international project led by NASA with its partners, the European Space Agency and the Canadian Space Agency. Image credit: NASA/Chris Gunn Text credit: Laura Betz, NASA's Goddard Space Flight Center, Greenbelt, Maryland NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Feasibility of solar power for Mars

NASA Technical Reports Server (NTRS)

Appelbaum, Joseph; Landis, Geoffrey A.

1991-01-01

NASA, through Project Pathfinder, has put in place an advanced technology program to address future needs of manned space exploration. Included in the missions under study is the establishment of outposts on the surface of Mars. The Surface Power program in Pathfinder is aimed at providing photovoltaic array technology for such an application (as well as for the lunar surface). Another important application is for unmanned precursor missions, such as the photovoltaic-power aircraft, which will scout landing sites and investigate Mars geology for a 1 to 2 year mission without landing on the surface. Effective design and utilization of solar energy depend to a large extent on adequate knowledge of solar radiation characteristics in the region of solar energy system operation. The two major climatic components needed for photovoltaic system designs are the distributions of solar insolation and ambient temperature. These distributions for the Martian climate are given at the two Viking lander locations but can also be used, to the first approximation, for other latitudes. One of the most important results is that there is a large diffuse component of the insolation, even at high optical depth, so that solar energy system operation is still possible. If the power system is to continue to generate power even on high optical opacity days, it is thus important that the photovoltaic system be designed to collect diffuse irradiance as well as direct. In absence of long term insolation and temperature data for Mars, the data presented can be used until updated data are available. The ambient temperature data are given as measured directly by the temperature sensor; the insolation data are calculated from optical depth measurements of the atmosphere.

Acidalia and Chryse Plains, Mars

NASA Image and Video Library

2000-06-14

Somewhere down there sits the Mars Pathfinder lander and Sojourner rover. This Mars Global Surveyor Mars Orbiter Camera view of the red planet shows the region that includes Ares Vallis and the Chryse Plains upon which both Mars Pathfinder and the Viking 1 landed in 1997 and 1976, respectively. Acidalia Planitia is the dark surface that dominates the center left. The Pathfinder site is immediately south of Acidalia, just left of center in this view. Also shown--the north polar cap is at the top, and Arabia Terra and Sinus Meridiani are to the right. The bluish-white features are clouds. This is a color composite of 9 red and 9 blue image strips taken by the Mars Global Surveyor Mars Orbiter Camera on 9 successive orbits from pole-to-pole during the calibration phase of the mission in March 1999. The color is computer-enhanced and is not shown as it would actually appear to the human eye. http://photojournal.jpl.nasa.gov/catalog/PIA02000

Measuring fN force variations in the presence of constant nN forces: a torsion pendulum ground test of the LISA Pathfinder free-fall mode

NASA Astrophysics Data System (ADS)

Russano, G.; Cavalleri, A.; Cesarini, A.; Dolesi, R.; Ferroni, V.; Gibert, F.; Giusteri, R.; Hueller, M.; Liu, L.; Pivato, P.; Tu, H. B.; Vetrugno, D.; Vitale, S.; Weber, W. J.

2018-02-01

LISA Pathfinder is a differential accelerometer with the main goal being to demonstrate the near perfect free-fall of reference test masses, as is needed for an orbiting gravitational wave observatory, with a target sensitivity of 30 fm s‑2 Hz-1/2 at 1 mHz. Any lasting background differential acceleration between the two test masses must be actively compensated, and noise associated with the applied actuation force can be a dominant source of noise. To remove this actuation, and the associated force noise, a ‘free-fall’ actuation control scheme has been designed; actuation is limited to brief impulses, with both test masses in free-fall in the time between the impulses, allowing measurement of the remaining acceleration noise sources. In this work, we present an on-ground torsion pendulum testing campaign of this technique and associated data analysis algorithms at a level nearing the sub-femto-g/\\sqrtHz performance required for LISA Pathfinder.

New perspective of undeployed rover

NASA Technical Reports Server (NTRS)

1997-01-01

This image features a different perspective of one of the first pictures taken by the Imager for Mars Pathfinder (IMP) lander shortly after its touchdown at 10:07 AM Pacific Daylight Time on July 4. The image has been transformed to a perspective that would match that of an observer standing at the point the image was taken. Sojourner is seen in the foreground in its stowed position on a solar panel of the lander. Both ramps, the rear of which Sojourner would use on July 5 to safely descend to the Martian surface, were still undeployed when this image was taken. The double hills called 'Twin Peaks' are clearly visible in the background.

The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

PathFinder: reconstruction and dynamic visualization of metabolic pathways.

PubMed

Goesmann, Alexander; Haubrock, Martin; Meyer, Folker; Kalinowski, Jörn; Giegerich, Robert

2002-01-01

Beyond methods for a gene-wise annotation and analysis of sequenced genomes new automated methods for functional analysis on a higher level are needed. The identification of realized metabolic pathways provides valuable information on gene expression and regulation. Detection of incomplete pathways helps to improve a constantly evolving genome annotation or discover alternative biochemical pathways. To utilize automated genome analysis on the level of metabolic pathways new methods for the dynamic representation and visualization of pathways are needed. PathFinder is a tool for the dynamic visualization of metabolic pathways based on annotation data. Pathways are represented as directed acyclic graphs, graph layout algorithms accomplish the dynamic drawing and visualization of the metabolic maps. A more detailed analysis of the input data on the level of biochemical pathways helps to identify genes and detect improper parts of annotations. As an Relational Database Management System (RDBMS) based internet application PathFinder reads a list of EC-numbers or a given annotation in EMBL- or Genbank-format and dynamically generates pathway graphs.

Detection of Micrometeoroids with LISA Pathfinder

NASA Astrophysics Data System (ADS)

Thorpe, Ira; Littenberg, Tyson; Janchez, Diego; Baker, John; The LISA Pathfinder Team Team

2017-01-01

The LISA Pathfinder mission (LPF), a joint ESA/NASA technology demonstration mission currently operating at the Sun-Earth L1 point, contains the most precise accelerometry system ever flown. Analysis suggests that LPF should have sufficient sensitivity to detect impacts of small micrometeoroids and dust through their transfer of momentum to the spacecraft. Moreover, LPF's ability to fully resolve both the linear and angular momentum transfer in three dimensions allows a magnitude, direction, and location to be estimated for each impact. We present preliminary results from a systematic search of the LISA Pathfinder data for such impacts and discuss the prospects for using these and future results to inform models of the formation and evolution of dust populations in the inner solar system. These models have wide applicability to both pure and applied space science, ranging from the physics of planet formation and dynamics of minor Solar System bodies to estimates of the micrometeorite hazard for future spacecraft. 2017 NASA Science Innovation Fund.

A torsion pendulum test of the Lisa Pathfinder free-fall mode

NASA Astrophysics Data System (ADS)

Russano, Giuliana; Dolesi, Rita; Cavalleri, Antonella; Hueller, Mauro; Vitale, Stefano; Weber, William Joseph; Tu, HaiBo

The LISA Pathfinder geodesic explorer mission for gravitational wave astronomy aims to demonstrate the proof of a low acceleration noise level. The relative acceleration between two test masses free falling in orbit is perturbed by the presence of a larger constant relative acceleration that must be actively compensated in order to keep the test particles centered inside an orbiting apparatus. The actuation force applied to compensate this effect introduces a dominant source of force noise. To suppress this noise source, a “free-fall” actuation control scheme has been designed: actuation is limited to brief impulses, with test masses in free fall in between two “kicks”, with this actuation-free motion then analyzed for the remaining sources of acceleration ultra noise. In this work, we will discuss and present preliminary data for an on-ground torsion pendulum experiment to test this technique, and the associated analysis algorithms, at a level nearing the sub-femto-g/sqrt(Hz) performance required for LISA Pathfinder.

Classification and Distribution of Mars Pathfinder Rocks Using Quantitative Morphologic Indices

NASA Technical Reports Server (NTRS)

Yingst, R. A.; Biederman, K. L.; Monhead, A. M.; Haldemann, A. F. C.; Kowalczyk, M. R.

2004-01-01

The Mars Pathfinder (MPF) landing site was predicted to contain a broad sampling of rock types varying in mineralogical, physical, mechanical and geochemical characteristics. Although rocks have been divided into several spectral categories based on Imager for Mars Pathfinder visible/near-infrared spectra, it has not been fully determined which of these stem from intrinsic mineralogical differences between rocks or rock surfaces, and which result from factors such as physical or chemical weathering. This has made isolation of unique mineralogy's difficult. Efforts in isolating and classifying spectral units among MPF rocks and soils have met with varying degrees of success, and the current understanding is such that many factors influencing spectral signatures cannot be quantified to a sufficient level so they may be removed. The result is that fundamental questions regarding information needed to reveal the present and past interactions between the rocks and rock surfaces and the Martian environment remain unanswered. But it is possible to approach the issue of identifying distinct rock and rock surface types from a different angle.

The Role of APEX as a Pathfinder for AtLAST

NASA Astrophysics Data System (ADS)

Wyrowski, Friedrich

2018-01-01

Now more than 12 years in operation, the Atacama Pathfinder Experiment (APEX) 12 m submillimeter telescope has significantly contributed to a wide variety of submillimeter astronomy science areas, ranging from the discoveries of new molecules to large and deep imaging of the submillimeter sky. While ALMA operation is in full swing, APEX is strengthening its role not only as pathfinder for studying large source samples and spatial scales to prepare detailed high angular resolution ALMA follow ups, but also as fast response instruments to complement new results from ALMA. Furthermore, APEX ensures southern hemisphere access for submillimeter projects complementing archival Herschel research as well as new SOFIA science. With new broadband and multipixel receivers as well as large cameras for wide-field continuum imaging, APEX will pave the way towards the science envisioned with ATLAST. In this contribution, the current status and ongoing upgrades of APEX will be discussed, with an emphasis on the importance of continuous cutting edge science and state-of-the-art instrumentation that will bridge the gap towards ATLAST.

Hydrogeochemical prospecting for porphyry copper deposits in the tropical-marine climate of Puerto Rico

USGS Publications Warehouse

Miller, W.R.; Ficklin, W.H.; Learned, R.E.

1982-01-01

A hydrogeochemical survey utilizing waters from streams and springs was conducted in the area of two known porphyry copper deposits in the tropical-marine climate of westcentral Puerto Rico. The most important pathfinder for regional hydrogeochemical surveys is sulfate which reflects the associated pyrite mineralization. Because of increased mobility due to intense chemical weathering and the low pH environment, dissolved copper can also be used as a pathfinder for regional surveys and has the advantage of distinguishing barren pyrite from pyrite associated with copper mineralization. For follow-up surveys, the most important pathfinders are copper, sulfate, pH, zinc, and fluoride. High concentrations of dissolved copper and moderate concentrations of sulfate is a diagnostic indication of nearby sources of copper minerals. An understanding of the geochemical processes taking place in the streambeds and the weathering environment, such as the precipitation of secondary copper minerals, contributes to the interpretation of the geochemical data and the selection of the most favorable areas for further exploration. ?? 1982.

Career pathfinders: a qualitative study of career development.

PubMed

Beutell, Icholas J; O'Hare, Marianne M

2006-04-01

This paper examined the perceptions of career path and issues of MBA students in response to Lore's The Pathfinder, a comprehensive career-planning model. Using internet discussion boards, an interactive dialogue was mentioned by participants in response to the components of Lore's model. The sample consisted of 50 fully employed MBA students enrolled in a course on self-assessment and career planning. A total of 1,781 separate postings were made and analyzed, using inductive analysis derived from discussion threads based on Lore's categories: comments on Lore's Pathfinder model, living a life you love (what's the holdup, career fantasies, work and family issues, and career selection), how to get there from here (commitment and future from the present), and designing your future career. Findings indicated several interesting trends in the career planning of current MBA students, particularly the importance of self or self-reflective observations in real time as students who are also fully employed formulate career plans. Implications for psychologists and career counselors, career development models, and suggestions for research are presented.

Experiments and Spectral Studies of Martian Volcanic Rocks: Implications for the Origin of Pathfinder Rocks and Soils

NASA Technical Reports Server (NTRS)

Rutherford, Malcolm J.; Mustard, Jack; Weitz, Catherine

2002-01-01

The composition and spectral properties of the Mars Pathfinder rocks and soils together with the identification of basaltic and andesitic Mars terrains based on Thermal Emission Spectrometer (TES) data raised interesting questions regarding the nature and origin of Mars surface rocks. We have investigated the following questions: (1) are the Pathfinder rocks igneous and is it possible these rocks could have formed by known igneous processes, such as equilibrium or fractional crystallization, operating within SNC magmas known to exist on Mars? If it is possible, what P (depth) and PH2O conditions are required? (2) whether TES-based interpretations of plagioclase-rich basalt and andesitic terrains in the south and north regions of Mars respectively are unique. Are the surface compositions of these regions plagioclase-rich, possibly indicating the presence of old AI-rich crust of Mars, or are the spectra being affected by something like surface weathering processes that might determine the spectral pyroxene to plagioclase ratio?

LISA Pathfinder: First steps to observing gravitational waves from space

NASA Astrophysics Data System (ADS)

McNamara, Paul; LISA Pathfinder Collaboration

2017-01-01

With the first direct detection of gravitational waves a little over a year ago, the gravitational window to the Universe has been opened. The gravitational wave spectrum spans many orders of magnitude in frequency, with several of the most interesting astronomical sources emitting gravitational waves at frequencies only observable from space The European Space Agency (ESA) has been active in the field of space-borne gravitational wave detection for many years, and in 2013 selected the Gravitational Universe as the science theme for the third large class mission in the Cosmic Vision science programme. In addition, ESA took the step of developing the LISA Pathfinder mission to demonstrate the critical technologies required for a future mission. The goal of the LISA Pathfinder mission is to place a test body in free fall such that any external forces (acceleration) are reduced to levels lower than those expected from the passage of a gravitational wave LISA Pathfinder was launched on the 3rd December 2015 from the European Spaceport in Kourou, French Guiana. After a series of 6 apogee raising manoeuvres, the satellite left earth orbit, and travelled to its final science orbit around the first Sun-Earth Lagrange point (L1). Following a relatively short commissioning phase, science operations began on 1st March 2016. In the following 3 months over 100 experiments and over 1500hours of noise measurements have been performed, demonstrating that the observation of gravitational waves from space can be realised.

Zebrafish foxP2 Zinc Finger Nuclease Mutant Has Normal Axon Pathfinding

PubMed Central

Xing, Lingyan; Hoshijima, Kazuyuki; Grunwald, David J.; Fujimoto, Esther; Quist, Tyler S.; Sneddon, Jacob; Chien, Chi-Bin; Stevenson, Tamara J.; Bonkowsky, Joshua L.

2012-01-01

foxP2, a forkhead-domain transcription factor, is critical for speech and language development in humans, but its role in the establishment of CNS connectivity is unclear. While in vitro studies have identified axon guidance molecules as targets of foxP2 regulation, and cell culture assays suggest a role for foxP2 in neurite outgrowth, in vivo studies have been lacking regarding a role for foxP2 in axon pathfinding. We used a modified zinc finger nuclease methodology to generate mutations in the zebrafish foxP2 gene. Using PCR-based high resolution melt curve analysis (HRMA) of G0 founder animals, we screened and identified three mutants carrying nonsense mutations in the 2nd coding exon: a 17 base-pair (bp) deletion, an 8bp deletion, and a 4bp insertion. Sequence analysis of cDNA confirmed that these were frameshift mutations with predicted early protein truncations. Homozygous mutant fish were viable and fertile, with unchanged body morphology, and no apparent differences in CNS apoptosis, proliferation, or patterning at embryonic stages. There was a reduction in expression of the known foxP2 target gene cntnap2 that was rescued by injection of wild-type foxP2 transcript. When we examined axon pathfinding using a pan-axonal marker or transgenic lines, including a foxP2-neuron-specific enhancer, we did not observe any axon guidance errors. Our findings suggest that foxP2 is not necessary for axon pathfinding during development. PMID:22937139

Zebrafish foxP2 zinc finger nuclease mutant has normal axon pathfinding.

PubMed

Xing, Lingyan; Hoshijima, Kazuyuki; Grunwald, David J; Fujimoto, Esther; Quist, Tyler S; Sneddon, Jacob; Chien, Chi-Bin; Stevenson, Tamara J; Bonkowsky, Joshua L

2012-01-01

foxP2, a forkhead-domain transcription factor, is critical for speech and language development in humans, but its role in the establishment of CNS connectivity is unclear. While in vitro studies have identified axon guidance molecules as targets of foxP2 regulation, and cell culture assays suggest a role for foxP2 in neurite outgrowth, in vivo studies have been lacking regarding a role for foxP2 in axon pathfinding. We used a modified zinc finger nuclease methodology to generate mutations in the zebrafish foxP2 gene. Using PCR-based high resolution melt curve analysis (HRMA) of G0 founder animals, we screened and identified three mutants carrying nonsense mutations in the 2(nd) coding exon: a 17 base-pair (bp) deletion, an 8bp deletion, and a 4bp insertion. Sequence analysis of cDNA confirmed that these were frameshift mutations with predicted early protein truncations. Homozygous mutant fish were viable and fertile, with unchanged body morphology, and no apparent differences in CNS apoptosis, proliferation, or patterning at embryonic stages. There was a reduction in expression of the known foxP2 target gene cntnap2 that was rescued by injection of wild-type foxP2 transcript. When we examined axon pathfinding using a pan-axonal marker or transgenic lines, including a foxP2-neuron-specific enhancer, we did not observe any axon guidance errors. Our findings suggest that foxP2 is not necessary for axon pathfinding during development.

Multispectral Imaging from Mars PATHFINDER

NASA Technical Reports Server (NTRS)

Ferrand, William H.; Bell, James F., III; Johnson, Jeffrey R.; Bishop, Janice L.; Morris, Richard V.

2007-01-01

The Imager for Mars Pathfinder (IMP) was a mast-mounted instrument on the Mars Pathfinder lander which landed on Mars Ares Vallis floodplain on July 4, 1997. During the 83 sols of Mars Pathfinders landed operations, the IMP collected over 16,600 images. Multispectral images were collected using twelve narrowband filters at wavelengths between 400 and 1000 nm in the visible and near infrared (VNIR) range. The IMP provided VNIR spectra of the materials surrounding the lander including rocks, bright soils, dark soils, and atmospheric observations. During the primary mission, only a single primary rock spectral class, Gray Rock, was recognized; since then, Black Rock, has been identified. The Black Rock spectra have a stronger absorption at longer wavelengths than do Gray Rock spectra. A number of coated rocks have also been described, the Red and Maroon Rock classes, and perhaps indurated soils in the form of the Pink Rock class. A number of different soil types were also recognized with the primary ones being Bright Red Drift, Dark Soil, Brown Soil, and Disturbed Soil. Examination of spectral parameter plots indicated two trends which were interpreted as representing alteration products formed in at least two different environmental epochs of the Ares Vallis area. Subsequent analysis of the data and comparison with terrestrial analogs have supported the interpretation that the rock coatings provide evidence of earlier martian environments. However, the presence of relatively uncoated examples of the Gray and Black rock classes indicate that relatively unweathered materials can persist on the martian surface.

Reconsidering the Theological and Ethical Implications of Extraterrestrial Life

NASA Technical Reports Server (NTRS)

Randolph, Richard O. (Editor); Race, Margaret S.; McKay, Christopher P.

1997-01-01

As we stand on the threshold of a new millennium, we also find ourselves at the brink of a new and exciting era in space exploration. In fact, this new era has already begun, with the successful landing and exploration of Mars by the Pathfinder mission in July 1997. Pathfinder represents an important scientific accomplishment for NASA because it demonstrated the agency's ability to successfully explore space at a relatively modest price. At the same time, Pathfinder revealed once again the genuine interest and fascination that people all over planet Earth have for space exploration. The recent Pathfinder mission to Mars was only the first in an ambitious series of NASA missions planned for exploration of Mars, Earth's nearest planetary neighbor where extraterrestrial life is a real possibility. In March 1998, the next step in this exploration takes place, when the Mars Global Surveyor--which is already in orbit around Mars--begins photographing and mapping the Martian surface. NASA plans to continue its exploration with additional landers and orbiters taking off for Mars every 26 months, when the paths of Mars and Earth bring them in closer proximity. By the year 2005, NASA hopes to launch a mission that will return martian samples to Earth. And, as early as 2011, astronauts could be rocketing from Earth for the first human landing on the Red Planet. In the distant future, there may be even more grandiose plans, including the possibility of engineering an atmosphere on Mars that could support biological life.

Laser Interferometry for Gravitational Wave Observation: LISA and LISA Pathfinder

NASA Technical Reports Server (NTRS)

Guzman, Felipe

2010-01-01

The Laser Interferometer Space Antenna (LISA) is a planned NASA-ESA gravitational wave observatory in the frequency range of 0.1mHz-100mHz. This observation band is inaccessible to ground-based detectors due to the large ground motions of the Earth. Gravitational wave sources for LISA include galactic binaries, mergers of supermasive black-hole binaries, extreme-mass-ratio inspirals, and possibly from as yet unimagined sources. LISA is a constellation of three spacecraft separated by 5 million km in an equilateral triangle, whose center follows the Earth in a heliocentric orbit with an orbital phase offset oF 20 degrees. Challenging technology is required to ensure pure geodetic trajectories of the six onboard test masses, whose distance fluctuations will be measured by interspacecraft laser interferometers with picometer accuracy. LISA Pathfinder is an ESA-launched technology demonstration mission of key LISA subsystems such us spacecraft control with micro-newton thrusters, test mass drag-free control, and precision laser interferometry between free-flying test masses. Ground testing of flight hardware of the Gravitational Reference Sensor and Optical Metrology subsystems of LISA Pathfinder is currently ongoing. An introduction to laser interferometric gravitational wave detection, ground-based observatories, and a detailed description of the two missions together with an overview of current investigations conducted by the community will bc discussed. The current status in development and implementation of LISA Pathfinder pre-flight systems and latest results of the ongoing ground testing efforts will also be presented

Clinical pathologist in Korea--training program and its roles in laboratories.

PubMed

Cho, Han-Ik; Lee, Kap No; Park, Jong-Woo; Park, Hyosoon; Kwak, Yun Sik

2002-01-01

A rapid development of practice of laboratory medicine in Korea owes its success to the clinical pathologists (CP), who have played a role of a pathfinder for laboratories. The Korean CP postgraduate education (residency) program is unique in that it is exclusively for laboratory medicine. The training program for clinical pathologists includes diagnostic hematology, diagnostic immunology, clinical microbiology, clinical chemistry, blood bank, diagnostic genetics, informatics and laboratory management. The program has produced a strong group of about 600 laboratory physicians, officially clinical pathologists since 1963. Most of Korean clinical pathologists work as laboratory directors, directors of university hospital laboratories or teaching faculty members in medical schools. The roles of clinical pathologists are laboratory management, interpretation of laboratory test results, clinical consulting services to clinicians and patients, ordering secondary tests after reviews of requested test results and utilization management. The clinical pathologists have developed clinical laboratories to be a main contributor for improved medical practice. During the last 40 years under the turbulent healthcare system, clinical pathologists have significantly contributed to safeguard the laboratory interests. The education program and the role of clinical pathologists are described.

KSC-08pd3868

NASA Image and Video Library

2008-11-07

CAPE CANAVERAL, Fla. -- In Building 1555 at Vandenberg Air Force Base in California, workers do a fit check on the mating of the Stage 1 to Stage 2 motors for the Taurus XL rocket that will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft. At right can be seen the avionics shelf. The avionics skirt, a graphite/epoxy structure, supports the avionics shelf and carries the primary structural loads from the fairing and payload cone. The aluminum avionics shelf supports the third stage avionics. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The launch of OCO is targeted for January. Photo credit: NASA/Randy Beaudoin, VAFB

Introduction of Virtualization Technology to Multi-Process Model Checking

NASA Technical Reports Server (NTRS)

Leungwattanakit, Watcharin; Artho, Cyrille; Hagiya, Masami; Tanabe, Yoshinori; Yamamoto, Mitsuharu

2009-01-01

Model checkers find failures in software by exploring every possible execution schedule. Java PathFinder (JPF), a Java model checker, has been extended recently to cover networked applications by caching data transferred in a communication channel. A target process is executed by JPF, whereas its peer process runs on a regular virtual machine outside. However, non-deterministic target programs may produce different output data in each schedule, causing the cache to restart the peer process to handle the different set of data. Virtualization tools could help us restore previous states of peers, eliminating peer restart. This paper proposes the application of virtualization technology to networked model checking, concentrating on JPF.

SRB Processing Facilities Media Event

NASA Image and Video Library

2016-03-01

Members of the news media view the high bay inside the Rotation, Processing and Surge Facility (RPSF) at NASA’s Kennedy Space Center in Florida. Inside the RPSF, engineers and technicians with Jacobs Engineering on the Test and Operations Support Contract, explain the various test stands. In the far corner is one of two pathfinders, or test versions, of solid rocket booster segments for NASA’s Space Launch System rocket. The Ground Systems Development and Operations Program and Jacobs are preparing the booster segments, which are inert, for a series of lifts, moves and stacking operations to prepare for Exploration Mission-1, deep-space missions and the journey to Mars.

Cognitive network organization and cockpit automation

NASA Technical Reports Server (NTRS)

Roske-Hofstrand, R. J.; Paap, K. R.

1985-01-01

Attention is given to a technique for the derivation of pilot cognitive networks from empirical data, which has been successfully used to guide the redesign of the Control Display Unit that serves as the primary interface of the complex flight management system being developed by NASA's Advanced Concepts Flight Simulator program. The 'pathfinder' algorithm of Schvaneveldt et al. (1985) is used to obtain the conceptual organization of four pilots by generating a family of link-weighted networks from a set of psychological distance data derived through similarity ratings. The degree of conceptual agreement between pilots is assessed, and the means of translating a cognitive network into a menu structure are noted.

KSC-2009-1656

NASA Image and Video Library

2009-02-03

VANDENBERG AIR FORCE BASE, Calif. -- Stages 1, 2 and 3 of Orbital Sciences’ Taurus XL launch vehicle for NASA’s Orbiting Carbon Observatory, or OCO, are parked under a tent at Space Launch Complex 576-E at Vandenberg Air Force Base in California. The OCO is an Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory will collect precise global measurements of carbon dioxide in the Earth's atmosphere. Scientists will analyze the data returned to better understand the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Launch is targeted for 1:51:30 a.m. PST Feb. 24. Photo credit: VAFB

KSC-2009-1654

NASA Image and Video Library

2009-02-03

VANDENBERG AIR FORCE BASE, Calif. -- Stages 1, 2 and 3 of Orbital Sciences’ Taurus XL launch vehicle for NASA’s Orbiting Carbon Observatory, or OCO, are transported from Building 1555 to Space Launch Complex 576-E at Vandenberg Air Force Base in California. The OCO is an Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory will collect precise global measurements of carbon dioxide in the Earth's atmosphere. Scientists will analyze the data returned to better understand the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Launch is targeted for 1:51:30 a.m. PST Feb. 24. Photo credit: VAFB

KSC-2009-1658

NASA Image and Video Library

2009-02-03

VANDENBERG AIR FORCE BASE, Calif. – Stages 1, 2 and 3 of Orbital Sciences’ Taurus XL launch vehicle for NASA’s Orbiting Carbon Observatory, or OCO, have arrived and are prepared for erection at Space Launch Complex 576-E at Vandenberg Air Force Base in California. The OCO is an Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory will collect precise global measurements of carbon dioxide in the Earth's atmosphere. Scientists will analyze the data returned to better understand the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Launch is targeted for 1:51:30 a.m. PST Feb. 24. Photo credit: VAFB

KSC-2009-1655

NASA Image and Video Library

2009-02-03

VANDENBERG AIR FORCE BASE, Calif. -- Stages 1, 2 and 3 of Orbital Sciences’ Taurus XL launch vehicle for NASA’s Orbiting Carbon Observatory, or OCO, arrive at Space Launch Complex 576-E at Vandenberg Air Force Base in California. The OCO is an Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory will collect precise global measurements of carbon dioxide in the Earth's atmosphere. Scientists will analyze the data returned to better understand the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Launch is targeted for 1:51:30 a.m. PST Feb. 24. Photo credit: VAFB

KSC-2009-1659

NASA Image and Video Library

2009-02-03

VANDENBERG AIR FORCE BASE, Calif. – Stages 1, 2 and 3 of Orbital Sciences’ Taurus XL launch vehicle for NASA’s Orbiting Carbon Observatory, or OCO, have arrived and are prepared for lifting onto Space Launch Complex 576-E at Vandenberg Air Force Base in California. The OCO is an Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory will collect precise global measurements of carbon dioxide in the Earth's atmosphere. Scientists will analyze the data returned to better understand the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Launch is targeted for 1:51:30 a.m. PST Feb. 24. Photo credit: VAFB

KSC-2009-1657

NASA Image and Video Library

2009-02-03

VANDENBERG AIR FORCE BASE, Calif. – Workers prepare to erect Stages 1, 2 and 3 of Orbital Sciences’ Taurus XL launch vehicle for NASA’s Orbiting Carbon Observatory, or OCO, at Space Launch Complex 576-E at Vandenberg Air Force Base in California. The OCO is an Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory will collect precise global measurements of carbon dioxide in the Earth's atmosphere. Scientists will analyze the data returned to better understand the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Launch is targeted for 1:51:30 a.m. PST Feb. 24. Photo credit: VAFB

Path Finding for Maximum Value of Information in Multi-Modal Underwater Wireless Sensor Networks

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

Gjanci, Petrika; Petrioli, Chiara; Basagni, Stefano

Here, we consider underwater multi-modal wireless sensor networks (UWSNs) suitable for applications on submarine surveillance and monitoring, where nodes offload data to a mobile autonomous underwater vehicle (AUV) via optical technology, and coordinate using acoustic communication. Sensed data are associated with a value, decaying in time. In this scenario, we address the problem of finding the path of the AUV so that the Value of Information (VoI) of the data delivered to a sink on the surface is maximized. We define a Greedy and Adaptive AUV Path-finding (GAAP) heuristic that drives the AUV to collect data from nodes depending onmore » the VoI of their data. For benchmarking the performance of AUV path-finding heuristics, we define an integer linear programming (ILP) formulation that accurately models the considered scenario, deriving a path that drives the AUV to collect and deliver data with the maximum VoI. In our experiments GAAP consistently delivers more than 80 percent of the theoretical maximum VoI determined by the ILP model. We also compare the performance of GAAP with that of other strategies for driving the AUV among sensing nodes, namely, random paths, TSP-based paths and a “lawn mower”-like strategy. Our results show that GAAP always outperforms every other heuristic in terms of delivered VoI, also obtaining higher energy efficiency.« less

Path Finding for Maximum Value of Information in Multi-Modal Underwater Wireless Sensor Networks

DOE PAGES

Gjanci, Petrika; Petrioli, Chiara; Basagni, Stefano; ...

2017-05-19

Here, we consider underwater multi-modal wireless sensor networks (UWSNs) suitable for applications on submarine surveillance and monitoring, where nodes offload data to a mobile autonomous underwater vehicle (AUV) via optical technology, and coordinate using acoustic communication. Sensed data are associated with a value, decaying in time. In this scenario, we address the problem of finding the path of the AUV so that the Value of Information (VoI) of the data delivered to a sink on the surface is maximized. We define a Greedy and Adaptive AUV Path-finding (GAAP) heuristic that drives the AUV to collect data from nodes depending onmore » the VoI of their data. For benchmarking the performance of AUV path-finding heuristics, we define an integer linear programming (ILP) formulation that accurately models the considered scenario, deriving a path that drives the AUV to collect and deliver data with the maximum VoI. In our experiments GAAP consistently delivers more than 80 percent of the theoretical maximum VoI determined by the ILP model. We also compare the performance of GAAP with that of other strategies for driving the AUV among sensing nodes, namely, random paths, TSP-based paths and a “lawn mower”-like strategy. Our results show that GAAP always outperforms every other heuristic in terms of delivered VoI, also obtaining higher energy efficiency.« less

Hypersonic Inflatable Aerodynamic Decelerator Ground Test Development

NASA Technical Reports Server (NTRS)

Del Corso, Jospeh A.; Hughes, Stephen; Cheatwood, Neil; Johnson, Keith; Calomino, Anthony

2015-01-01

Hypersonic Inflatable Aerodynamic Decelerator (HIAD) technology readiness levels have been incrementally matured by NASA over the last thirteen years, with most recent support from NASA's Space Technology Mission Directorate (STMD) Game Changing Development Program (GCDP). Recently STMD GCDP has authorized funding and support through fiscal year 2015 (FY15) for continued HIAD ground developments which support a Mars Entry, Descent, and Landing (EDL) study. The Mars study will assess the viability of various EDL architectures to enable a Mars human architecture pathfinder mission planned for mid-2020. At its conclusion in November 2014, NASA's first HIAD ground development effort had demonstrated success with fabricating a 50 W/cm2 modular thermal protection system, a 400 C capable inflatable structure, a 10-meter scale aeroshell manufacturing capability, together with calibrated thermal and structural models. Despite the unquestionable success of the first HIAD ground development effort, it was recognized that additional investment was needed in order to realize the full potential of the HIAD technology capability to enable future flight opportunities. The second HIAD ground development effort will focus on extending performance capability in key technology areas that include thermal protection system, lifting-body structures, inflation systems, flight control, stage transitions, and 15-meter aeroshell scalability. This paper presents an overview of the accomplishments under the baseline HIAD development effort and current plans for a follow-on development effort focused on extending those critical technologies needed to enable a Mars Pathfinder mission.

A distributed analysis and visualization system for model and observational data

NASA Technical Reports Server (NTRS)

Wilhelmson, Robert B.

1994-01-01

Software was developed with NASA support to aid in the analysis and display of the massive amounts of data generated from satellites, observational field programs, and from model simulations. This software was developed in the context of the PATHFINDER (Probing ATmospHeric Flows in an Interactive and Distributed EnviRonment) Project. The overall aim of this project is to create a flexible, modular, and distributed environment for data handling, modeling simulations, data analysis, and visualization of atmospheric and fluid flows. Software completed with NASA support includes GEMPAK analysis, data handling, and display modules for which collaborators at NASA had primary responsibility, and prototype software modules for three-dimensional interactive and distributed control and display as well as data handling, for which NSCA was responsible. Overall process control was handled through a scientific and visualization application builder from Silicon Graphics known as the Iris Explorer. In addition, the GEMPAK related work (GEMVIS) was also ported to the Advanced Visualization System (AVS) application builder. Many modules were developed to enhance those already available in Iris Explorer including HDF file support, improved visualization and display, simple lattice math, and the handling of metadata through development of a new grid datatype. Complete source and runtime binaries along with on-line documentation is available via the World Wide Web at: http://redrock.ncsa.uiuc.edu/ PATHFINDER/pathre12/top/top.html.

The New Millenium Program ST-5 Mission: Nanosatellite Constellation Trailblazer

NASA Technical Reports Server (NTRS)

Slavin, James A.

1999-01-01

NASA's New Millenium Program has recently selected the Nanosatellite Constellation Trailblazer (NCT) as its fifth mission (ST-5). NCT will consist of 3 small, very capable and highly autonomous satellites which will be operated as a single "constellation" with minimal ground operations support. Each spacecraft will be approximately 40 cm in diameter by 20 cm in height and weigh only 20 kg. These small satellites will incorporate 8 new technologies essential to the further miniaturization of space science spacecraft which need space flight validation. In this talk we will describe in greater detail the NCT mission concept and goals, the exciting new technologies it will validate, and the role of miniaturized particles and fields sensors in this project. Finally, NCT's pathfinder function for such future NASA missions as Magnetotail Constellation and Inner Magnetosphere Constellation will be discussed.

Genesis Sample Return Capsule Overview

NASA Technical Reports Server (NTRS)

Willcockson, Bill

2005-01-01

I. Simple Entry Capsule Concept: a) Spin-Stabilized/No Active Control Systems; b) Ballistic Entry for 11.04 km/sec Velocity; c) No Heatshield Separation During Entry; d) Parachute Deploy via g-Switch + Timer. II. Stardust Design Inheritance a) Forebody Shape; b) Seal Concepts; c) Parachute Deploy Control; d) Utah Landing Site (UTTR). III. TPS Systems a) Heatshield - Carbon-Carbon - First Planetary Entry; b) Backshell - SLA-561V - Flight Heritage from Pathfinder, MER; d) Forebody Structural Penetrations Aerothermal and TPS Design Process has the Same Methodology as Used for Pathfinder, MER Flight Vehicles.

Cloud-Aerosol LIDAR and Infrared Pathfinder Satellite Observation (CALIPSO) Spacecraft: Independent Technical Assessment

NASA Technical Reports Server (NTRS)

Gilbrech, Richard J.; McManamen, John P.; Wilson, Timmy R.; Robinson, Frank; Schoren, William R.

2004-01-01

CALIPSO is a joint science mission between the CNES, LaRC and GSFC. It was selected as an Earth System Science Pathfinder satellite mission in December 1998 to address the role of clouds and aerosols in the Earth's radiation budget. The spacecraft includes a NASA light detecting and ranging (LIDAR) instrument, a NASA wide-field camera and a CNES imaging infrared radiometer. The scope of this effort was a review of the Proteus propulsion bus design and an assessment of the potential for personnel exposure to hydrazine propellant.

Towards a Framework for Generating Tests to Satisfy Complex Code Coverage in Java Pathfinder

NASA Technical Reports Server (NTRS)

Staats, Matt

2009-01-01

We present work on a prototype tool based on the JavaPathfinder (JPF) model checker for automatically generating tests satisfying the MC/DC code coverage criterion. Using the Eclipse IDE, developers and testers can quickly instrument Java source code with JPF annotations covering all MC/DC coverage obligations, and JPF can then be used to automatically generate tests that satisfy these obligations. The prototype extension to JPF enables various tasks useful in automatic test generation to be performed, such as test suite reduction and execution of generated tests.

Optical Bench Interferometer - From LISA Pathfinder to NGO/eLISA

NASA Astrophysics Data System (ADS)

Taylor, A.; d'Arcio, L.; Bogenstahl, J.; Danzmann, K.; Diekmann, C.; Fitzsimons, E. D.; Gerberding, O.; Heinzel, G.; Hennig, J.-S.; Hogenhuis, H.; Killow, C. J.; Lieser, M.; Lucarelli, S.; Nikolov, S.; Perreur-Lloyd, M.; Pijnenburg, J.; Robertson, D. I.; Sohmer, A.; Tröbs, M.; Ward, H.; Weise, D.

2013-01-01

We present a short summary of some optical bench construction and alignment developments that build on experience gained during the LISA Pathfinder optical bench assembly. These include evolved fibre injectors, a new beam vector measurement system, and thermally stable mounting hardware. The beam vector measurement techniques allow the alignment of beams to targets with absolute accuracy of a few microns and 20 microradians. We also describe a newly designed ultra-low-return beam dump that is expected to be a crucial element in the control of ghost beams on the optical benches.

Sojourner APXS at Shark

NASA Image and Video Library

1997-08-28

NASA's Sojourner rover is seen next to the rock "Shark," in this image taken by the Imager for Mars Pathfinder (IMP) near the end of daytime operations on Sol 52. The rover's Alpha Proton X-Ray Spectrometer is deployed against the rock. The rock "Wedge" is in the foreground. The Sojourner rover is seen next to the rock "Shark," in this image taken by the Imager for Mars Pathfinder (IMP) near the end of daytime operations on Sol 52. The rover's Alpha Proton X-Ray Spectrometer is deployed against the rock. The rock "Wedge" is in the foreground.

Physarum solver: A biologically inspired method of road-network navigation

NASA Astrophysics Data System (ADS)

Tero, Atsushi; Kobayashi, Ryo; Nakagaki, Toshiyuki

2006-04-01

We have proposed a mathematical model for the adaptive dynamics of the transport network in an amoeba-like organism, the true slime mold Physarum polycephalum. The model is based on physiological observations of this species, but can also be used for path-finding in the complicated networks of mazes and road maps. In this paper, we describe the physiological basis and the formulation of the model, as well as the results of simulations of some complicated networks. The path-finding method used by Physarum is a good example of cellular computation.

Cloud-Aerosol LIDAR and Infrared Pathfinder Satellite Observation (CALIPSO) Spacecraft: Independent Technical Assessment

NASA Technical Reports Server (NTRS)

Gilbrech, Richard J.; McManamen, John P.; Wilson, Timmy R.; Robinson, Frank; Schoren, William R.

2005-01-01

CALIPSO is a joint science mission between the CNES, LaRC and GSFC. It was selected as an Earth System Science Pathfinder satellite mission in December 1998 to address the role of clouds and aerosols in the Earth's radiation budget. The spacecraft includes a NASA light detecting and ranging (LIDAR) instrument, a NASA wide-field camera and a CNES imaging infrared radiometer. The scope of this effort was a review of the Proteus propulsion bus design and an assessment of the potential for personnel exposure to hydrazine propellant.

Selection of radio sources for Venus balloon-Pathfinder Delta-DOR navigation at 1.7 GHz

NASA Technical Reports Server (NTRS)

Liewer, K. M

1986-01-01

In order to increase the success rate of the Delta-DOR (Delta-Differential One-way Range) VLBI navigational support for the French-Soviet Venus Balloon and Halley Pathfinder projects, forty-four extragalactic radio sources were observed in advance of these projects to determine which were suitable for use as reference sources. Of these forty-four radio sources taken from the existing JPL radio source catalogue, thirty-six were determined to be of sufficient strength for use in Delta-DOR VLBI navigation.

Testing Phoenix Mars Lander Parachute in Idaho

NASA Technical Reports Server (NTRS)

2008-01-01

NASA's Phoenix Mars Lander will parachute for nearly three minutes as it descends through the Martian atmosphere on May 25, 2008. Extensive preparations for that crucial period included this drop test near Boise, Idaho, in October 2006.

The parachute used for the Phoenix mission is similar to ones used by NASA's Viking landers in 1976. It is a 'disk-gap-band' type of parachute, referring to two fabric components -- a central disk and a cylindrical band -- separated by a gap.

Although the Phoenix parachute has a smaller diameter (11.8 meters or 39 feet) than the parachute for the 2007 Mars Pathfinder landing (12.7 meters or 42 feet), its Viking configuration results in slightly larger drag area. The smaller physical size allows for a stronger system because, given the same mass and volume restrictions, a smaller parachute can be built using higher strength components. The Phoenix parachute is approximately 1.5 times stronger than Pathfinder's. Testing shows that it is nearly two times stronger than the maximum opening force expected during its use at Mars.

Engineers used a dart-like weight for the drop testing in Idaho. On the Phoenix spacecraft, the parachute is attached the the backshell. The backshell is the upper portion of a capsule around the lander during the flight from Earth to Mars and protects Phoenix during the initial portion of the descent through Mars' atmosphere.

Phoenix will deploy its parachute at about 12.6 kilometers (7.8 miles) in altitude and at a velocity of 1.7 times the speed of sound. A mortar on the spacecraft fires to deploy the parachute, propelling it away from the backshell into the supersonic flow. The mortar design for Phoenix is essentially the same as Pathfinder's. The parachute and mortar are collectively called the 'parachute decelerator system.' Pioneer Aerospace, South Windsor, Conn., produced this system for Phoenix. The same company provided the parachute decelerator systems for Pathfinder, Mars Polar Lander, Spirit, and Opportunity, ensuring that lessons learned from past programs were incorporated into the Phoenix system.

During the first 25 seconds of the three-minute period when Phoenix descends on its parachute, the spacecraft will cast away its heat shield and extend its three legs. About 43 seconds before reaching the surface of Mars, the lander will shed the parachute by separating from the backshell. The lander will begin firing its descent thrusters half a second after the separation from the backshell and continue using them until touchdown.

The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

New Earth-Observing Instrument Installed on the International Space Station

NASA Image and Video Library

2017-12-08

In January 2013, a new Earth-observing instrument was installed on the International Space Station (ISS). ISERV Pathfinder consists of a commercial camera, a telescope, and a pointing system, all positioned to look through the Earth-facing window of ISS’s Destiny module. ISERV Pathfinder is intended as an engineering exercise, with the long-term goal of developing a system for providing imagery to developing nations as they monitor natural disasters and environmental concerns. The image above is the “first light” from the new ISERV camera system, taken at 1:44 p.m. local time on February 16, 2013. It shows the Rio San Pablo as it empties into the Golfo de Montijo in Veraguas, Panama. It is an ecological transition zone, changing from agriculture and pastures to mangrove forests, swamps, and estuary systems. The area has been designated a protected area by the National Environmental Authority (ANAM) of Panama and is listed as a “wetland of international importance” under the Ramsar Convention. (Note that the image is rotated so that north is to the upper right.) “ISERV’s full potential is yet to be seen, but we hope it will really make a difference in people’s lives,” said principal investigator Burgess Howell of NASA’s Marshall Space Flight Center. “For example, if an earthen dam gives way in Bhutan, we want to be able to show officials where the bridge is out or where a road is washed out or a power substation is inundated. This kind of information is critical to focus and speed rescue efforts.” The instrument will be controlled from NASA Marshall in Huntsville, Alabama, in collaboration with researchers at hubs in Central America, East Africa, and the Hindu Kush–Himalaya region. They will rely on positioning software to know where the space station is at each moment and to calculate the next chance to view a particular area on the ground. If there's a good viewing opportunity, the SERVIR team will instruct the camera to take high-resolution photographs at 3 to 7 frames per second, totaling as many as 100 images per pass. With a resolution down to 3.2 meters (10 feet), it will be possible to spot fairly small details and objects. The current mission will test the limitations of Pathfinder and identify measures for improvements in a more permanent system. For instance, the engineering team is working to determine how the geometry of the ISS window affects the imagery; how much sunlight is needed to capture clear images; and how the atmosphere affects that clarity. This characterization phase will last several weeks to a few months. Eventually, ISERV should be made available to the natural hazards community and to basic research scientists. ISERV is short for ISS SERVIR Environmental Research and Visualization system. Together with the U.S. Agency for International Development, NASA runs the SERVIR program to provide satellite data, maps, and other tools to environmental decisionmakers in developing countries. (Servir is a Spanish word meaning “to serve.”) Learn more about the SERVIR program by clicking here: servirglobal.net/Global.aspx NASA image by Burgess Howell, SERVIR Global program. Caption by Dauna Coulter, NASA Marshall Space Flight Center, and Mike Carlowicz, NASA Earth Observatory. Instrument: ISS - ISERV Pathfinder Credit: NASA Earth Observatory - 1.usa.gov/12Aqmg9 NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Barnacle Bill in Super Resolution from Insurance Panorama

NASA Technical Reports Server (NTRS)

1998-01-01

Barnacle Bill is a small rock immediately west-northwest of the Mars Pathfinder lander and was the first rock visited by the Sojourner Rover's alpha proton X-ray spectrometer (APXS) instrument. This image shows super resolution techniques applied to the first APXS target rock, which was never imaged with the rover's forward cameras. Super resolution was applied to help to address questions about the texture of this rock and what it might tell us about its mode of origin.

This view of Barnacle Bill was produced by combining the 'Insurance Pan' frames taken while the IMP camera was still in its stowed position on sol2. The composite color frames that make up this anaglyph were produced for both the right and left eye of the IMP. The right eye composite consists of 5 frames, taken with different color filters, the left eye consists of only 1 frame. The resultant image from each eye was enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution panchromatic frame that is sharper than an individual frame would be. These panchromatic frames were then colorized with the red, green, and blue filtered images from the same sequence. The color balance was adjusted to approximate the true color of Mars.

The anaglyph view was produced by combining the left with the right eye color composite frames by assigning the left eye composite view to the red color plane and the right eye composite view to the green and blue color planes (cyan), to produce a stereo anaglyph mosaic. This mosaic can be viewed in 3-D on your computer monitor or in color print form by wearing red-blue 3-D glasses.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. Barnacle Bill is a small rock immediately west-northwest of the Mars Pathfinder lander and was the first rock visited by the Sojourner Rover's alpha proton X-ray spectrometer (APXS) instrument.

Electro-Statically Stricted Polymers (ESSP)

NASA Technical Reports Server (NTRS)

Liu, C.; Bar-Cohen, Y.; Leary, S.

1999-01-01

Miniature, lightweight, miser actuators that operate similar to biological muscles can be used to develop robotic devices with unmatched capabilities and impact many technology areas. Electroactive polymers (EAP) offer the potential to producing such actuators and their main attractive feature is their ability to induce relatively large bending or longitudinal strain. EAP actuators can change the paradigm about the complexity of robots, where robotic components such as motors, gears, bearings, and others can be eliminated with simple drive mechanisms. Generally, these materials produce a relatively low force and the applications that can be considered at the current state of the art are relatively limited. While improved material are being developed there is a need for methods to develop longitudinal actuators that can contract similar to muscles. In this study, the authors began investigating the electromechanical behavior of polymers in reaction to a complex configuration of electric fields. A computer model was used to simulate the electromechanical response. Efforts were made to develop both the material basis as well as the electromechanical modeling of the actuator.

Free-Suspension Residual Flexibility Testing of Space Station Pathfinder: Comparison to Fixed-Base Results

NASA Technical Reports Server (NTRS)

Tinker, Michael L.

1998-01-01

Application of the free-suspension residual flexibility modal test method to the International Space Station Pathfinder structure is described. The Pathfinder, a large structure of the general size and weight of Space Station module elements, was also tested in a large fixed-base fixture to simulate Shuttle Orbiter payload constraints. After correlation of the Pathfinder finite element model to residual flexibility test data, the model was coupled to a fixture model, and constrained modes and frequencies were compared to fixed-base test. modes. The residual flexibility model compared very favorably to results of the fixed-base test. This is the first known direct comparison of free-suspension residual flexibility and fixed-base test results for a large structure. The model correlation approach used by the author for residual flexibility data is presented. Frequency response functions (FRF) for the regions of the structure that interface with the environment (a test fixture or another structure) are shown to be the primary tools for model correlation that distinguish or characterize the residual flexibility approach. A number of critical issues related to use of the structure interface FRF for correlating the model are then identified and discussed, including (1) the requirement of prominent stiffness lines, (2) overcoming problems with measurement noise which makes the antiresonances or minima in the functions difficult to identify, and (3) the use of interface stiffness and lumped mass perturbations to bring the analytical responses into agreement with test data. It is shown that good comparison of analytical-to-experimental FRF is the key to obtaining good agreement of the residual flexibility values.

Navigating Without Road Maps: The Early Business of Automobile Route Guide Publishing in the United States

NASA Astrophysics Data System (ADS)

Bauer, John T.

2018-05-01

In the United States, automobile route guides were important precursors to the road maps that Americans are familiar with today. Listing turn-by-turn directions between cities, they helped drivers navigate unmarked, local roads. This paper examines the early business of route guide publishing through the Official Automobile Blue Book series of guides. It focuses specifically on the expansion, contraction, and eventual decline of the Blue Book publishing empire and also the work of professional "pathfinders" that formed the company's data-gathering infrastructure. Be- ginning in 1901 with only one volume, the series steadily grew until 1920, when thirteen volumes were required to record thousands of routes throughout the country. Bankruptcy and corporate restructuring in 1921 forced the publishers to condense the guide into a four-volume set in 1922. Competition from emerging sheet maps, along with the nationwide standardization of highway numbers, pushed a switch to an atlas format in 1926. Blue Books, however, could not remain competitive and disappeared after 1937. "Pathfinders" were employed by the publishers and equipped with reliable automobiles. Soon they developed a shorthand notation system for recording field notes and efficiently incorporating them into the development workflow. Although pathfinders did not call themselves cartographers, they were geographical data field collectors and considered their work to be an "art and a science," much the same as modern-day cartographers. The paper concludes with some comments about the place of route guides in the history of American commercial cartography and draws some parallels between "pathfinders" and the digital road mappers of today.

Notochord alters the permissiveness of myotome for pathfinding by an identified motoneuron in embryonic zebrafish.

PubMed

Beattie, C E; Eisen, J S

1997-02-01

During zebrafish development, identified motoneurons innervate cell-specific regions of each trunk myotome. One motoneuron, CaP, extends an axon along the medial surface of the ventral myotome. To learn how this pathway is established during development, the CaP axon was used as an assay to ask whether other regions of the myotome were permissive for normal CaP pathfinding. Native myotomes were replaced with donor myotomes in normal or reversed dorsoventral orientations and CaP pathfinding was assayed. Ventral myotomes were permissive for CaP axons, even when they were taken from older embryos, suggesting that the CaP pathway remained present on ventral myotome throughout development. Dorsal myotomes from young embryos were also permissive for CaP axons, however, older dorsal myotomes were non-permissive, showing that permissiveness of dorsal myotome for normal CaP pathfinding diminished over time. This process appears to depend on signals from the embryo, since dorsal myotomes matured in vitro remained permissive for CaP axons. Genetic mosaics between wild-type and floating head mutant embryos revealed notochord involvement in dorsal myotome change of permissiveness. Dorsal and ventral myotomes from both younger and older floating head mutant embryos were permissive for CaP axons. These data suggest that initially both dorsal and ventral myotomes are permissive for CaP axons but as development proceeds, there is a notochord-dependent decrease in permissiveness of dorsal myotome for CaP axonal outgrowth. This change participates in restricting the CaP pathway to the ventral myotome and thus to neuromuscular specificity.

Charge-Induced Force Noise on Free-Falling Test Masses: Results from LISA Pathfinder

NASA Astrophysics Data System (ADS)

Armano, M.; Audley, H.; Auger, G.; Baird, J. T.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Brandt, N.; Bursi, A.; Caleno, M.; Cavalleri, A.; Cesarini, A.; Cruise, M.; Danzmann, K.; de Deus Silva, M.; Diepholz, I.; Dolesi, R.; Dunbar, N.; Ferraioli, L.; Ferroni, V.; Fitzsimons, E. D.; Flatscher, R.; Freschi, M.; Gallegos, J.; García Marirrodriga, C.; Gerndt, R.; Gesa, L.; Gibert, F.; Giardini, D.; Giusteri, R.; Grimani, C.; Grzymisch, J.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hueller, M.; Huesler, J.; Inchauspé, H.; Jennrich, O.; Jetzer, P.; Johlander, B.; Karnesis, N.; Kaune, B.; Killow, C. J.; Korsakova, N.; Lloro, I.; Liu, L.; López-Zaragoza, J. P.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Martín, V.; Martin-Polo, L.; Martino, J.; Martin-Porqueras, F.; Mateos, I.; McNamara, P. W.; Mendes, J.; Mendes, L.; Moroni, A.; Nofrarias, M.; Paczkowski, S.; Perreur-Lloyd, M.; Petiteau, A.; Pivato, P.; Plagnol, E.; Prat, P.; Ragnit, U.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D. I.; Rozemeijer, H.; Rivas, F.; Russano, G.; Sarra, P.; Schleicher, A.; Slutsky, J.; Sopuerta, C.; Sumner, T. J.; Texier, D.; Thorpe, J. I.; Trenkel, C.; Vetrugno, D.; Vitale, S.; Wanner, G.; Ward, H.; Wass, P. J.; Wealthy, D.; Weber, W. J.; Wittchen, A.; Zanoni, C.; Ziegler, T.; Zweifel, P.; LISA Pathfinder Collaboration

2017-04-01

We report on electrostatic measurements made on board the European Space Agency mission LISA Pathfinder. Detailed measurements of the charge-induced electrostatic forces exerted on free-falling test masses (TMs) inside the capacitive gravitational reference sensor are the first made in a relevant environment for a space-based gravitational wave detector. Employing a combination of charge control and electric-field compensation, we show that the level of charge-induced acceleration noise on a single TM can be maintained at a level close to 1.0 fm s-2 Hz-1 /2 across the 0.1-100 mHz frequency band that is crucial to an observatory such as the Laser Interferometer Space Antenna (LISA). Using dedicated measurements that detect these effects in the differential acceleration between the two test masses, we resolve the stochastic nature of the TM charge buildup due to interplanetary cosmic rays and the TM charge-to-force coupling through stray electric fields in the sensor. All our measurements are in good agreement with predictions based on a relatively simple electrostatic model of the LISA Pathfinder instrument.

Mars Pathfinder and Mars Global Surveyor Outreach Compilation

NASA Astrophysics Data System (ADS)

1999-09-01

This videotape is a compilation of the best NASA JPL (Jet Propulsion Laboratory) videos of the Mars Pathfinder and Mars Global Surveyor missions. The mission is described using animation and narration as well as some actual footage of the entire sequence of mission events. Included within these animations are the spacecraft orbit insertion; descent to the Mars surface; deployment of the airbags and instruments; and exploration by Sojourner, the Mars rover. JPL activities at spacecraft control during significant mission events are also included at the end. The spacecraft cameras pan the surrounding Mars terrain and film Sojourner traversing the surface and inspecting rocks. A single, brief, processed image of the Cydonia region (Mars face) at an oblique angle from the Mars Global Surveyor is presented. A description of the Mars Pathfinder mission, instruments, landing and deployment process, Mars approach, spacecraft orbit insertion, rover operation are all described using computer animation. Actual color footage of Sojourner as well as a 360 deg pan of the Mars terrain surrounding the spacecraft is provided. Lower quality black and white photography depicting Sojourner traversing the Mars surface and inspecting Martian rocks also is included.

Charge-Induced Force Noise on Free-Falling Test Masses: Results from LISA Pathfinder.

PubMed

Armano, M; Audley, H; Auger, G; Baird, J T; Binetruy, P; Born, M; Bortoluzzi, D; Brandt, N; Bursi, A; Caleno, M; Cavalleri, A; Cesarini, A; Cruise, M; Danzmann, K; de Deus Silva, M; Diepholz, I; Dolesi, R; Dunbar, N; Ferraioli, L; Ferroni, V; Fitzsimons, E D; Flatscher, R; Freschi, M; Gallegos, J; García Marirrodriga, C; Gerndt, R; Gesa, L; Gibert, F; Giardini, D; Giusteri, R; Grimani, C; Grzymisch, J; Harrison, I; Heinzel, G; Hewitson, M; Hollington, D; Hueller, M; Huesler, J; Inchauspé, H; Jennrich, O; Jetzer, P; Johlander, B; Karnesis, N; Kaune, B; Killow, C J; Korsakova, N; Lloro, I; Liu, L; López-Zaragoza, J P; Maarschalkerweerd, R; Madden, S; Mance, D; Martín, V; Martin-Polo, L; Martino, J; Martin-Porqueras, F; Mateos, I; McNamara, P W; Mendes, J; Mendes, L; Moroni, A; Nofrarias, M; Paczkowski, S; Perreur-Lloyd, M; Petiteau, A; Pivato, P; Plagnol, E; Prat, P; Ragnit, U; Ramos-Castro, J; Reiche, J; Romera Perez, J A; Robertson, D I; Rozemeijer, H; Rivas, F; Russano, G; Sarra, P; Schleicher, A; Slutsky, J; Sopuerta, C; Sumner, T J; Texier, D; Thorpe, J I; Trenkel, C; Vetrugno, D; Vitale, S; Wanner, G; Ward, H; Wass, P J; Wealthy, D; Weber, W J; Wittchen, A; Zanoni, C; Ziegler, T; Zweifel, P

2017-04-28

We report on electrostatic measurements made on board the European Space Agency mission LISA Pathfinder. Detailed measurements of the charge-induced electrostatic forces exerted on free-falling test masses (TMs) inside the capacitive gravitational reference sensor are the first made in a relevant environment for a space-based gravitational wave detector. Employing a combination of charge control and electric-field compensation, we show that the level of charge-induced acceleration noise on a single TM can be maintained at a level close to 1.0  fm s^{-2} Hz^{-1/2} across the 0.1-100 mHz frequency band that is crucial to an observatory such as the Laser Interferometer Space Antenna (LISA). Using dedicated measurements that detect these effects in the differential acceleration between the two test masses, we resolve the stochastic nature of the TM charge buildup due to interplanetary cosmic rays and the TM charge-to-force coupling through stray electric fields in the sensor. All our measurements are in good agreement with predictions based on a relatively simple electrostatic model of the LISA Pathfinder instrument.

Mars Pathfinder and Mars Global Surveyor Outreach Compilation

NASA Technical Reports Server (NTRS)

1999-01-01

This videotape is a compilation of the best NASA JPL (Jet Propulsion Laboratory) videos of the Mars Pathfinder and Mars Global Surveyor missions. The mission is described using animation and narration as well as some actual footage of the entire sequence of mission events. Included within these animations are the spacecraft orbit insertion; descent to the Mars surface; deployment of the airbags and instruments; and exploration by Sojourner, the Mars rover. JPL activities at spacecraft control during significant mission events are also included at the end. The spacecraft cameras pan the surrounding Mars terrain and film Sojourner traversing the surface and inspecting rocks. A single, brief, processed image of the Cydonia region (Mars face) at an oblique angle from the Mars Global Surveyor is presented. A description of the Mars Pathfinder mission, instruments, landing and deployment process, Mars approach, spacecraft orbit insertion, rover operation are all described using computer animation. Actual color footage of Sojourner as well as a 360 deg pan of the Mars terrain surrounding the spacecraft is provided. Lower quality black and white photography depicting Sojourner traversing the Mars surface and inspecting Martian rocks also is included.

adrift, a novel bnl-induced Drosophila gene, required for tracheal pathfinding into the CNS.

PubMed

Englund, C; Uv, A E; Cantera, R; Mathies, L D; Krasnow, M A; Samakovlis, C

1999-04-01

Neurons and glial cells provide guidance cues for migrating neurons. We show here that migrating epithelial cells also contact specific neurons and glia during their pathfinding, and we describe the first gene required in the process. In wild-type Drosophila embryos, the ganglionic tracheal branch navigates a remarkably complex path along specific neural and glial substrata, switching substrata five times before reaching its ultimate target in the CNS. In adrift mutants, ganglionic branches migrate normally along the intersegmental nerve, but sporadically fail to switch to the segmental nerve and enter the CNS; they wind up meandering along the ventral epidermis instead. adrift encodes a novel nuclear protein with an evolutionarily conserved motif. The gene is required in the trachea and is expressed in the leading cells of migrating ganglionic branches where it is induced by the branchless FGF pathway. We propose that Adrift regulates expression of tracheal genes required for pathfinding on the segmental nerve, and FGF induction of adrift expression in migrating tracheal cells promotes the switch from the intersegmental to the segmental nerve.

Sedimentary Geochemistry of Martian Samples from the Pathfinder Mission

NASA Technical Reports Server (NTRS)

McLennan, Scott M.

2001-01-01

The purpose of this research project was to evaluate the APXS data collected on soils and rocks at the Pathfinder site in terms of sedimentary geochemistry. Below are described the major findings of this research: (1) An influential model to explain the chemical variation among Pathfinder soils and rocks is a two component mixing model where rocks of fairly uniform composition mix with soil of uniform composition; (2) The very strong positive correlation between MgO and SO, points to a control by a MgSO4 mineral however, spectroscopic data continue to suggest that Fe-sulfates, notably schwertmannite and jarosite, may be important components; (3) In an attempt to better understand the causes of complexities in mixing relationships, the possible influence of sedimentary transport has been evaluated; (4) Another aspect of this research has been to examine the possibility of sedimentary silica being a significant phase on Mars; and (5) On Earth, the geochemistry of sedimentary rocks has been used to constrain the chemical composition of the continental crust and an important part of this research was to evaluate this approach for Mars.

Verifying Diagnostic Software

NASA Technical Reports Server (NTRS)

Lindsey, Tony; Pecheur, Charles

2004-01-01

Livingstone PathFinder (LPF) is a simulation-based computer program for verifying autonomous diagnostic software. LPF is designed especially to be applied to NASA s Livingstone computer program, which implements a qualitative-model-based algorithm that diagnoses faults in a complex automated system (e.g., an exploratory robot, spacecraft, or aircraft). LPF forms a software test bed containing a Livingstone diagnosis engine, embedded in a simulated operating environment consisting of a simulator of the system to be diagnosed by Livingstone and a driver program that issues commands and faults according to a nondeterministic scenario provided by the user. LPF runs the test bed through all executions allowed by the scenario, checking for various selectable error conditions after each step. All components of the test bed are instrumented, so that execution can be single-stepped both backward and forward. The architecture of LPF is modular and includes generic interfaces to facilitate substitution of alternative versions of its different parts. Altogether, LPF provides a flexible, extensible framework for simulation-based analysis of diagnostic software; these characteristics also render it amenable to application to diagnostic programs other than Livingstone.

Delta II Mars Pathfinder

NASA Technical Reports Server (NTRS)

1998-01-01

Final preparations for lift off of the DELTA II Mars Pathfinder Rocket are shown. Activities include loading the liquid oxygen, completing the construction of the Rover, and placing the Rover into the Lander. After the countdown, important visual events include the launch of the Delta Rocket, burnout and separation of the three Solid Rocket Boosters, and the main engine cutoff. The cutoff of the main engine marks the beginning of the second stage engine. After the completion of the second stage, the third stage engine ignites and then cuts off. Once the third stage engine cuts off spacecraft separation occurs.

Interior structure and seasonal mass redistribution of Mars from radio tracking of Mars Pathfinder

NASA Technical Reports Server (NTRS)

Folkner, W. M.; Yoder, C. F.; Yuan, D. N.; Standish, E. M.; Preston, R. A.

1997-01-01

Doppler and range measurements to the Mars Pathfinder lander made using its radio communications system have been combined with similar measurements from the Viking landers to estimate improved values of the precession of Mars' pole of rotation and the variation in Mars' rotation rate. The observed precession of -7576 +/- 35 milliarc seconds of angle per year implies a dense core and constrains possible models of interior composition. The estimated annual variation in rotation is in good agreement with a model of seasonal mass exchange of carbon dioxide between the atmosphere and ice caps.

AGU Pathfinder: Career and Professional Development Resources for Earth and Space Scientists

NASA Astrophysics Data System (ADS)

Harwell, D. E.; Asher, P. M.; Hankin, E. R.; Janick, N. G.; Marasco, L.

2017-12-01

The American Geophysical Union (AGU) is committed to inspiring and educating present and future generations of diverse, innovative, and creative Earth and space scientists. To meet our commitment, AGU provides career and educational resources, webinars, mentoring, and support for students and professionals at each level of development to reduce barriers to achievement and to promote professional advancement. AGU is also working with other organizations and educational institutions to collaborate on projects benefiting the greater geoscience community. The presentation will include an overview of current Pathfinder efforts, collaborative efforts, and an appeal for additional partnerships.

Interior structure and seasonal mass redistribution of Mars from radio tracking of Mars Pathfinder.

PubMed

Folkner, W M; Yoder, C F; Yuan, D N; Standish, E M; Preston, R A

1997-12-05

Doppler and range measurements to the Mars Pathfinder lander made using its radio communications system have been combined with similar measurements from the Viking landers to estimate improved values of the precession of Mars' pole of rotation and the variation in Mars' rotation rate. The observed precession of -7576 +/- 35 milliarc seconds of angle per year implies a dense core and constrains possible models of interior composition. The estimated annual variation in rotation is in good agreement with a model of seasonal mass exchange of carbon dioxide between the atmosphere and ice caps.

Charge Management in LISA Pathfinder: The Continuous Discharging Experiment

NASA Astrophysics Data System (ADS)

Ewing, Becca Elizabeth

2018-01-01

Test mass charging is a significant source of excess force and force noise in LISA Pathfinder (LPF). The planned design scheme for mitigation of charge induced force noise in LISA is a continuous discharge by UV light illumination. We report on analysis of a charge management experiment on-board LPF conducted during December 2016. We discuss the measurement of test mass charging noise with and without continuous UV illumination, in addition to the dynamic response in the continuous discharge scheme. Results of the continuous discharge system will be discussed for their application to operating LISA with lower test mass charge.

Results from the Mars Pathfinder camera.

PubMed

Smith, P H; Bell, J F; Bridges, N T; Britt, D T; Gaddis, L; Greeley, R; Keller, H U; Herkenhoff, K E; Jaumann, R; Johnson, J R; Kirk, R L; Lemmon, M; Maki, J N; Malin, M C; Murchie, S L; Oberst, J; Parker, T J; Reid, R J; Sablotny, R; Soderblom, L A; Stoker, C; Sullivan, R; Thomas, N; Tomasko, M G; Wegryn, E

1997-12-05

Images of the martian surface returned by the Imager for Mars Pathfinder (IMP) show a complex surface of ridges and troughs covered by rocks that have been transported and modified by fluvial, aeolian, and impact processes. Analysis of the spectral signatures in the scene (at 440- to 1000-nanometer wavelength) reveal three types of rock and four classes of soil. Upward-looking IMP images of the predawn sky show thin, bluish clouds that probably represent water ice forming on local atmospheric haze (opacity approximately 0.5). Haze particles are about 1 micrometer in radius and the water vapor column abundance is about 10 precipitable micrometers.

Mars PathFinder Rover Traverse Image

NASA Technical Reports Server (NTRS)

1998-01-01

This figure contains an azimuth-elevation projection of the 'Gallery Panorama.' The original Simple Cylindrical mosaic has been reprojected to the inside of a sphere so that lines of constant azimuth radiate from the center and lines of constant elevation are concentric circles. This projection preserves the resolution of the original panorama. Overlaid onto the projected Martian surface is a delineation of the Sojourner rover traverse path during the 83 Sols (Martian days) of Pathfinder surface operations. The rover path was reproduced using IMP camera 'end of day' and 'Rover movie' image sequences and rover vehicle telemetry data as references.

The effect of environmental initiatives on NASA specifications and standards activities

NASA Technical Reports Server (NTRS)

Griffin, Dennis; Webb, David; Cook, Beth

1995-01-01

The NASA Operational Environment Team (NOET) has conducted a survey of NASA centers specifications and standards that require the use of Ozone Depleting Substances (ODS's) (Chlorofluorocarbons (CFCs), Halons, and chlorinated solvents). The results of this survey are presented here, along with a pathfinder approach utilized at Marshall Space Flight Center (MSFC) to eliminate the use of ODS's in targeted specifications and standards. Presented here are the lessons learned from a pathfinder effort to replace CFC-113 in a significant MSFC specification for cleaning and cleanliness verification methods for oxygen, fuel and pneumatic service, including Shuttle propulsion elements.

Mars Pathfinder Wheel Abrasion Experiment Ground Test

NASA Technical Reports Server (NTRS)

Keith, Theo G., Jr.; Siebert, Mark W.

1998-01-01

The National Aeronautics and Space Administration (NASA) sent a mission to the martian surface, called Mars Pathfinder. The mission payload consisted of a lander and a rover. The primary purpose of the mission was demonstrating a novel entry, descent, and landing method that included a heat shield, a parachute, rockets, and a cocoon of giant air bags. Once on the surface, the spacecraft returned temperature measurements near the Martian surface, atmosphere pressure, wind speed measurements, and images from the lander and rover. The rover obtained 16 elemental measurements of rocks and soils, performed soil-mechanics, atmospheric sedimentation measurements, and soil abrasiveness measurements.

Mars Pathfinder: The Wheel Abrasion Experiment

NASA Technical Reports Server (NTRS)

1996-01-01

NASA Lewis Research Center's Wheel Abrasion Experiment (WAE) will measure the amount of wear on wheel surfaces of the Mars Pathfinder rover. WAE uses thin films of Al, Ni, and Pt (ranging in thickness from 200 to 1000 angstroms) deposited on black, anodized Al strips attached to the rover wheel. As the wheel moves across the martian surface, changes in film reflectivity will be monitored by reflected sunlight. These changes, measured as output from a special photodetector mounted on the rover chassis, will be due to abrasion of the metal films by martian surface sand, dust, and clay.

Pathfinder Atomic Power Plant Nozzle Galling Test, Final Report

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

None, None

1961-12-29

Galling tests of 304, 17-4PH, and chrome-plated 304 stainless-steel nozzles with 304 stainless-steel sleeves were conducted at Pathflnder reactor conditions of 480 deg F, 600 psig. A horizontal force was imposed on the sleeve with the nozzle inserted; and the nozzle was moved axially to determine galling tendencies. Galling was produced on both the 304 and 17-4PH stainless-steel nozzles. The chrome-plated 304-stainless-steel nozzles were cycled numerous times without galling. On the basis of these tests, chrome-plated 304-stainless- steel is the material selected for the Pathfinder boiler fuel-element nozzle.

Summary of Results from the Risk Management Program for the Mars Microrover Flight Experiment

NASA Technical Reports Server (NTRS)

Shishko, Robert; Matijevic, Jacob R.

2000-01-01

On 4 July 1997, the Mars Pathfinder landed on the surface of Mars carrying the first planetary rover, known as the Sojourner. Formally known as the Microrover Flight Experiment (MFEX), the Sojourner was a low cost, high-risk technology demonstration, in which new risk management techniques were tried. This paper summarizes the activities and results of the effort to conduct a low-cost, yet meaningful risk management program for the MFEX. The specific activities focused on cost, performance, schedule, and operations risks. Just as the systems engineering process was iterative and produced successive refinements of requirements, designs, etc., so was the risk management process. Qualitative risk assessments were performed first to gain some insights for refining the microrover design and operations concept. These then evolved into more quantitative analyses. Risk management lessons from the manager's perspective is presented for other low-cost, high-risk space missions.

Report on the Loss of the Mars Polar Lander and Deep Space 2 Missions

NASA Technical Reports Server (NTRS)

Albee, Arden; Battel, Steven; Brace, Richard; Burdick, Garry; Casani, John; Lavell, Jeffrey; Leising, Charles; MacPherson, Duncan; Burr, Peter; Dipprey, Duane

2000-01-01

NASA's Mars Surveyor Program (MSP) began in 1994 with plans to send spacecraft to Mars every 26 months. Mars Global Surveyor (MGS), a global mapping mission, was launched in 1996 and is currently orbiting Mars. Mars Surveyor '98 consisted of Mars Climate Orbiter (MCO) and Mars Polar Lander (MPL). Lockheed Martin Astronautics (LMA) was the prime contractor for Mars Surveyor '98. The Jet Propulsion Laboratory (JPL), California Institute of Technology, manages the Mars Surveyor Program for NASA's Office of Space Science. MPL was developed under very tight funding constraints. The combined development cost of MPL and MCO, including the cost of the two launch vehicles, was approximately the same as the development cost of the Mars Pathfinder mission, including the cost of its single launch vehicle. The MPL project accepted the challenge to develop effective implementation methodologies consistent with programmatic requirements.

Thermal Testing of Ablators in the NASA Johnson Space Center Radiant Heat Test Facility

NASA Technical Reports Server (NTRS)

Del Papa, Steven; Milhoan, Jim; Remark, Brian; Suess, Leonard

2016-01-01

A spacecraft's thermal protection system (TPS) is required to survive the harsh environment experienced during reentry. Accurate thermal modeling of the TPS is required to since uncertainties in the thermal response result in higher design margins and an increase in mass. The Radiant Heat Test Facility (RHTF) located at the NASA Johnson Space Center (JSC) replicates the reentry temperatures and pressures on system level full scale TPS test models for the validation of thermal math models. Reusable TPS, i.e. tile or reinforced carbon-carbon (RCC), have been the primary materials tested in the past. However, current capsule designs for MPCV and commercial programs have required the use of an ablator TPS. The RHTF has successfully completed a pathfinder program on avcoat ablator material to demonstrate the feasibility of ablator testing. The test results and corresponding ablation analysis results are presented in this paper.

Exact and Approximate Probabilistic Symbolic Execution

NASA Technical Reports Server (NTRS)

Luckow, Kasper; Pasareanu, Corina S.; Dwyer, Matthew B.; Filieri, Antonio; Visser, Willem

2014-01-01

Probabilistic software analysis seeks to quantify the likelihood of reaching a target event under uncertain environments. Recent approaches compute probabilities of execution paths using symbolic execution, but do not support nondeterminism. Nondeterminism arises naturally when no suitable probabilistic model can capture a program behavior, e.g., for multithreading or distributed systems. In this work, we propose a technique, based on symbolic execution, to synthesize schedulers that resolve nondeterminism to maximize the probability of reaching a target event. To scale to large systems, we also introduce approximate algorithms to search for good schedulers, speeding up established random sampling and reinforcement learning results through the quantification of path probabilities based on symbolic execution. We implemented the techniques in Symbolic PathFinder and evaluated them on nondeterministic Java programs. We show that our algorithms significantly improve upon a state-of- the-art statistical model checking algorithm, originally developed for Markov Decision Processes.

SRB Processing Facilities Media Event

NASA Image and Video Library

2016-03-01

Members of the news media view the high bay inside the Rotation, Processing and Surge Facility (RPSF) at NASA’s Kennedy Space Center in Florida. Kerry Chreist, with Jacobs Engineering on the Test and Operations Support Contract, talks with a reporter about the booster segments for NASA’s Space Launch System (SLS) rocket. In the far corner, in the vertical position, is one of two pathfinders, or test versions, of solid rocket booster segments for the SLS rocket. The Ground Systems Development and Operations Program and Jacobs are preparing the booster segments, which are inert, for a series of lifts, moves and stacking operations to prepare for Exploration Mission-1, deep-space missions and the journey to Mars.

KSC-08pd2046

NASA Image and Video Library

2008-07-14

VANDENBERG AIR FORCE BASE, Calif. -- An Alliant motor designated for Stage 3 of a Taurus rocket is weighed by Orbital Sciences workers in Building 1555 at Vandenberg AFB. The Taurus will launch the Orbiting Carbon Observatory, or OCO, in January 2009. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. OCO will provide space-based observations of atmospheric carbon dioxide (CO2), the principal human-initiated driver of climate change. Mature technologies will be used to address NASA's highest priority carbon cycle measurement requirement. NASA's Jet Propulsion Laboratory leads the OCO effort. Orbital Sciences Corporation is providing the Taurus launch vehicle; Hamilton Sundstrand Sensor Systems, the OCO spacecraft. Photo credit: NASA/Randy Beaudoin

KSC-08pd2044

NASA Image and Video Library

2008-07-14

VANDENBERG AIR FORCE BASE, Calif. -- An Alliant motor designated for Stage 3 of a Taurus rocket is weighed by Orbital Sciences workers in Building 1555 at Vandenberg AFB. The Taurus will launch the Orbiting Carbon Observatory, or OCO, in January 2009. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. OCO will provide space-based observations of atmospheric carbon dioxide (CO2), the principal human-initiated driver of climate change. Mature technologies will be used to address NASA's highest priority carbon cycle measurement requirement. NASA's Jet Propulsion Laboratory leads the OCO effort. Orbital Sciences Corporation is providing the Taurus launch vehicle; Hamilton Sundstrand Sensor Systems, the OCO spacecraft. Photo credit: NASA/Randy Beaudoin

KSC-08pd2045

NASA Image and Video Library

2008-07-14

VANDENBERG AIR FORCE BASE, Calif. -- An Alliant motor designated for Stage 3 of a Taurus rocket is weighed by Orbital Sciences workers in Building 1555 at Vandenberg AFB. The Taurus will launch the Orbiting Carbon Observatory, or OCO, in January 2009. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. OCO will provide space-based observations of atmospheric carbon dioxide (CO2), the principal human-initiated driver of climate change. Mature technologies will be used to address NASA's highest priority carbon cycle measurement requirement. NASA's Jet Propulsion Laboratory leads the OCO effort. Orbital Sciences Corporation is providing the Taurus launch vehicle; Hamilton Sundstrand Sensor Systems, the OCO spacecraft. Photo credit: NASA/Randy Beaudoin

Automatic remote sensing detection of the convective boundary layer structure over flat and complex terrain using the novel PathfinderTURB algorithm

NASA Astrophysics Data System (ADS)

Poltera, Yann; Martucci, Giovanni; Hervo, Maxime; Haefele, Alexander; Emmenegger, Lukas; Brunner, Dominik; Henne, stephan

2016-04-01

We have developed, applied and validated a novel algorithm called PathfinderTURB for the automatic and real-time detection of the vertical structure of the planetary boundary layer. The algorithm has been applied to a year of data measured by the automatic LIDAR CHM15K at two sites in Switzerland: the rural site of Payerne (MeteoSwiss station, 491 m, asl), and the alpine site of Kleine Scheidegg (KSE, 2061 m, asl). PathfinderTURB is a gradient-based layer detection algorithm, which in addition makes use of the atmospheric variability to detect the turbulent transition zone that separates two low-turbulence regions, one characterized by homogeneous mixing (convective layer) and one above characterized by free tropospheric conditions. The PathfinderTURB retrieval of the vertical structure of the Local (5-10 km, horizontal scale) Convective Boundary Layer (LCBL) has been validated at Payerne using two established reference methods. The first reference consists of four independent human-expert manual detections of the LCBL height over the year 2014. The second reference consists of the values of LCBL height calculated using the bulk Richardson number method based on co-located radio sounding data for the same year 2014. Based on the excellent agreement with the two reference methods at Payerne, we decided to apply PathfinderTURB to the complex-terrain conditions at KSE during 2014. The LCBL height retrievals are obtained by tilting the CHM15K at an angle of 19 degrees with respect to the horizontal and aiming directly at the Sphinx Observatory (3580 m, asl) on the Jungfraujoch. This setup of the CHM15K and the processing of the data done by the PathfinderTURB allows to disentangle the long-transport from the local origin of gases and particles measured by the in-situ instrumentation at the Sphinx Observatory. The KSE measurements showed that the relation amongst the LCBL height, the aerosol layers above the LCBL top and the gas + particle concentration is all but trivial. Retrieving the structure of the LCBL along the line of sight connecting KSE to the Sphinx Observatory allows to monitor when the LCBL top reaches the altitude of the in-situ instrumentation at the Sphinx and to relate the measured gas + particle concentration with the locally-produced aerosols. On the other hand, when the LCBL top is lower than the Sphinx altitude, the measured concentration of gas + particle at the Sphinx is either due to long transport of aerosols (>100 km) or to the residual aerosol layer reaching the Sphinx's height or to non-local (> 5 km and <100 km) CBL aerosols advected at the Sphinx's height. Except when the aerosol layer is decoupled from the LCBL underneath, for all the other cases the CHM15K sees the probed layer as a continuous (not necessarily well-mixed) aerosol layer starting at the KSE surface. The depth of this continuous layer has been retrieved by the PathfinderTURB and related with the black carbon absorption coefficient measured at Sphinx. The result of the comparison shows clearly that the depth of the layer is well correlated with the absorption coefficient measured at the Sphinx. This is an important result that allows not only to retrieve real-time CBL heights in an automatic and trustworthy way, but also to adapt the retrievals to complex-terrain and complex-atmospheric conditions with customized tilted instrument settings.

Harnessing the Power of the Sun

NASA Technical Reports Server (NTRS)

2005-01-01

The Environmental Research Aircraft and Sensor Technology (ERAST) Alliance was created in 1994 and operated for 9 years as a NASA-sponsored coalition of 28 members from small companies, government, universities, and nonprofit organizations. ERAST s goal was to foster development of remotely piloted aircraft technology for scientific, humanitarian, and commercial purposes. Some of the aircraft in the ERAST Alliance were intended to fly unmanned at high altitudes for days at a time, and flying for such durations required alternative sources of power that did not add weight. The most successful solution for this type of sustained flight is the lightest solar energy. Photovoltaic cells convert sunlight directly into electricity. They are made of semi-conducting materials similar to those used in computer chips. When sunlight is absorbed, electrons are knocked loose from their atoms, allowing electricity to flow. Under the ERAST Alliance, two solar-powered technology demonstration aircraft, Pathfinder and Helios, were developed. Pathfinder is a lightweight, remotely piloted flying wing aircraft that demonstrated the technology of applying solar cells for long-duration, high-altitude flight. Solar arrays covering most of the upper wing surface provide power for the aircraft s electric motors, avionics, communications, and other electronic systems. Pathfinder also has a backup battery system that can provide power for between 2 and 5 hours to allow limited-duration flight after dark. It was designed, built, and operated by AeroVironment, Inc., of Monrovia, California. On September 11, 1995, Pathfinder reached an altitude of 50,500 feet, setting a new altitude record for solar-powered aircraft. The National Aeronautic Association presented the NASA-industry team with an award for 1 of the 10 Most Memorable Record Flights of 1995.

Apical root canal transportation of different pathfinding systems and their effects on shaping ability of ProTaper Next

PubMed Central

Türker, Sevinç-Aktemur

2015-01-01

Background This study aimed to compare glide path preparation of different pathfinding systems and their effects on the apical transportation of ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland) in mesial root canals of extracted human mandibular molars, using digital subtraction radiography. Material and Methods The mesial canals of 40 mandibular first molars (with curvature angles between 25° and 35°) were selected for this study. The specimens were divided randomly into 4 groups with 10 canals each. Glide paths were created in group 1 with #10, #15 and #20 K-type (Dentsply Maillefer, Ballaigues, Switzerland) stainless steel manual files; in group 2 with Path-File (Dentsply Maillefer) #1, #2, and #3 and in group 3 with #16 ProGlider (Dentsply Maillefer) rotary instruments; in group 4 no glide paths were created. All canals were instrumented up to ProTaper Next X2 to the working length. A double digital radiograph technique was used, pre and post-instrumentation, to assess whether apical transportation and/or aberration in root canal morphology occurred. Instrument failures were also recorded. The data were analyzed statistically using ANOVA and Tukey tests (p<0.05). Results No significant differences were found among groups regarding apical transportation (p>0.05). Two ProTaper Next instruments failed in-group 4. Conclusions Within the parameters of this study, there was no difference between the performance of path-finding files and ProTaper Next system maintained root canal curvature well and was safe to use either with path-finding files or alone. Key words:Glide path, PathFile, ProGlider, ProTaper Next, transportation. PMID:26330936

Periodontal status among adolescents in Georgia. A pathfinder study.

PubMed

Levin, Liran; Margvelashvili, Vladimer; Bilder, Leon; Kalandadze, Manana; Tsintsadze, Nino; Machtei, Eli E

2013-01-01

Objectives. The aim of the present pathfinder study was to screen and map the periodontal status of Georgian population in accordance with the guidelines of the World Health Organization for population based surveys. Methods. During 2012, a pathfinder study was conducted to collect this data. For the periodontal portion of the study, 15-year-old school children were examined in the capital city of Tbilisi as well as in two other large cities and 4 smaller villages. All participants were examined by a trained dental team in a classroom using a dental mirror and a periodontal probe. Periodontal examination included plaque scores, calculus scores, probing depth measurements and bleeding on probing. These measurements were recorded for the Ramfjord index teeth. Results. A total of 397 15-year-old participants were examined in this pathfinder study. There were 240 females (60.45%) and 157 males (39.55%). Of the total participants 196 (49.37%) were urban adolescents while 201 (50.63%) were from rural communities. Mean probing depth was 3.34 ± 0.57 mm with a range of 1 to 10 mm; a relatively high proportion (34.26%) of these subjects presented with at least one site with pockets of 5 mm or deeper. Males presented with greater plaque, calculus and probing depths than females. When urban and rural populations were compared, urban participants presented with more plaque, probing depths and bleeding on probing. Greater pocket depths were found to be related to the presence of plaque calculus and bleeding on probing. Conclusions. Overall, rather high incidences of periodontal pockets ≥ 5 mm were detected in this population. This data should serve to prepare further more detailed epidemiological studies that will serve to plan and implement prevent and treat strategies for periodontal diseases in Georgia and also help make manpower decisions.

Filopodial adhesion does not predict growth cone steering events in vivo.

PubMed

Isbister, C M; O'Connor, T P

1999-04-01

Migration of growth cones is in part mediated by adhesive interactions between filopodia and the extracellular environment, transmitting forces and signals necessary for pathfinding. To elucidate the role of substrate adhesivity in growth cone pathfinding, we developed an in vivo assay for measuring filopodial-substrate adhesivity using the well-characterized Ti pioneer neuron pathway of the embryonic grasshopper limb. Using time-lapse imaging and a combination of rhodamine-phalloidin injections and DiI labeling, we demonstrate that the filopodial retraction rate after treatment with cytochalasin D or elastase reflects the degree of filopodial-substrate adhesivity. Measurements of filopodial retraction rates along regions of known differing substrate adhesivities confirmed the use of this assay to examine filopodial-substrate adhesion during in vivo pathfinding events. We analyzed 359 filopodia from 22 Ti growth cones and found that there is no difference between the retraction rates of filopodia extending toward the correct target (on-axis) and filopodia extending away from the correct target (off-axis). These results indicate on-axis and off-axis filopodia have similar substrate adherence. Interestingly, we observed a 300% increase in the extension rates of on-axis filopodia during Ti growth cone turning events. Therefore, in addition to providing filopodia with important guidance information, regional cues are capable of modulating the filopodial extension rate. The homogeneity in filopodial retraction rates, even among these turning growth cones in which differential adhesivity might be expected to be greatest, strongly establishes that differential adhesion does not govern Ti pioneer neuron migration rate or pathfinding. We propose that the presence of local differences in receptor-mediated second messenger cascades and the resulting assembly of force-generating machinery may underlie the ability of filopodial contacts to regulate growth cone steering in vivo.

The Data Processor of the JEM-EUSO pathfinders

NASA Astrophysics Data System (ADS)

Scotti, V.; Osteria, G.

2014-06-01

JEM-EUSO is a wide-angle refractive UV telescope being proposed for attachment to the Japanese Experiment Module on ISS. The main goal of the mission is to study Extreme Energy Cosmic Rays. Two pathfinder mission are now in progress: EUSO-TA and EUSO-Balloon. The EUSO-TA project foresees the installation of a telescope prototype in the Telescope Array site. The aim of this project is to calibrate the telescope with the TA fluorescence detector. An initial run of one year starting from 2013 is foreseen. EUSO-Balloon is a pathfinder mission in which a prototype telescope will be mounted on a stratospheric balloon. The main aim of this mission is to perform a end-to-end test of all the key technologies and instrumentation of JEM-EUSO detectors and to prove the global detection chain. EUSO-Balloon will measure the UV background fundamental for the development of the simulations. EUSO-Balloon has the potential to detect Extensive Air Showers from above, paving the way for any future space-based EECR observatory. We will present the Data Processor of the pathfinders. The DP is the component of the Electronics System which performs data management and instrument control. The DP controls front-end electronics, performs 2nd level trigger filtering, tags events with arrival time and payload position through a GPS system, manages mass memory for data storage, measures live and dead time of the telescope, provides signals for time synchronization of the event, performs housekeeping monitor and handles interface to the telemetry system. We will describe the main components of the DP, the state-of-the-art and the results of the tests carried out.

Space Technology 7 Disturbance Reduction System - precision control flight Validation

NASA Technical Reports Server (NTRS)

Carmain, Andrew J.; Dunn, Charles; Folkner, William; Hruby, Vlad; Spence, Doug; O'Donnell, James; Markley, Landis; Maghami, Peiman; Hsu, Oscar; Demmons, N.;

Live Ultra-High Definition from the International Space Station

NASA Technical Reports Server (NTRS)

Grubbs, Rodney; George, Sandy

2017-01-01

The first ever live downlink of Ultra-High Definition (UHD) video from the International Space Station (ISS) was the highlight of a 'Super Session' at the National Association of Broadcasters (NAB) in April 2017. The Ultra-High Definition video downlink from the ISS all the way to the Las Vegas Convention Center required considerable planning, pushed the limits of conventional video distribution from a space-craft, and was the first use of High Efficiency Video Coding (HEVC) from a space-craft. The live event at NAB will serve as a pathfinder for more routine downlinks of UHD as well as use of HEVC for conventional HD downlinks to save bandwidth. HEVC may also enable live Virtual Reality video downlinks from the ISS. This paper will describe the overall work flow and routing of the UHD video, how audio was synchronized even though the video and audio were received many seconds apart from each other, and how the demonstration paves the way for not only more efficient video distribution from the ISS, but also serves as a pathfinder for more complex video distribution from deep space. The paper will also describe how a 'live' event was staged when the UHD coming from the ISS had a latency of 10+ seconds. Finally, the paper will discuss how NASA is leveraging commercial technologies for use on-orbit vs. creating technology as was required during the Apollo Moon Program and early space age.

Successful Completion of the JWST OGSE2 Cryogenic Test at JSC Chamber-A While Managing Numerous Challenges

NASA Technical Reports Server (NTRS)

Park, Sang C.; Brinckerhoff, Pamela; Franck, Randy; Schweickart, Rusty; Thomson, Shaun; Burt, Bill; Ousley, Wes

2016-01-01

The James Webb Space Telescope (JWST) Optical Telescope Element (OTE) assembly is the largest optically stable infrared-optimized telescope currently being manufactured and assembled, and scheduled for launch in 2018. The JWST OTE, including the primary mirrors, secondary mirror, and the Aft Optics Subsystems (AOS) are designed to be passively cooled and operate at near 45 degrees Kelvin. Due to the size of its large sunshield in relation to existing test facilities, JWST cannot be optically or thermally tested as a complete observatory-level system at flight temperatures. As a result, the telescope portion along with its instrument complement will be tested as a single unit very late in the program, and on the program schedule critical path. To mitigate schedule risks, a set of 'pathfinder' cryogenic tests will be performed to reduce program risks by demonstrating the optical testing capabilities of the facility, characterizing telescope thermal performance, and allowing project personnel to learn valuable testing lessons off-line. This paper describes the 'pathfinder' cryogenic test program, focusing on the recently completed second test in the series called the Optical Ground Support Equipment 2 (OGSE2) test. The JWST OGSE2 was successfully completed within the allocated project schedule while faced with numerous conflicting thermal requirements during cool-down to the final cryogenic operational temperatures, and during warm-up after the cryo-stable optical tests. The challenges include developing a pre-test cool-down and warm-up profiles without a reliable method to predict the thermal behaviors in a rarified helium environment, and managing the test article hardware safety driven by the project Limits and Constraints (L&C's). Furthermore, OGSE2 test included the time critical Aft Optics Subsystem (AOS), a part of the flight Optical Telescope Element that would need to be placed back in the overall telescope assembly integrations. The OGSE2 test requirements included the strict adherence of the project contamination controls due to the presence of the contamination sensitive flight optical elements. The test operations required close coordination of numerous personnel while they being exposed and trained for the 'final' combined OTE and instrument cryo-test in 2017. This paper will also encompass the OGSE2 thermal data look-back review.

Pathfinder Rover, Airbags, & Martian Terrain

NASA Image and Video Library

1997-07-05

This is one of the first pictures taken by the camera on the Mars Pathfinder lander shortly after its touchdown at 10:07 AM Pacific Daylight Time on July 4, 1997. The small rover, named Sojourner, is seen in the foreground in its position on a solar panel of the lander. The white material on either side of the rover is part of the deflated airbag system used to absorb the shock of the landing. Between the rover and the horizon is the rock-strewn martian surface. Two hills are seen in the right distance, profiled against the light brown sky. http://photojournal.jpl.nasa.gov/catalog/PIA00611

Airbags and Sojourner Rover

NASA Image and Video Library

1997-07-05

This image from the Imager for Mars Pathfinder (IMP) camera shows the rear part of the Sojourner rover, the rolled-up rear ramp, and portions of the partially deflated airbags. The Alpha Proton X-ray Spectrometer instrument is protruding from the rear (right side) of the rover. The airbags behind the rover are presently blocking the ramp from being safely unfurled. The ramps are a pair of deployable metal reels that will provide a track for the rover as it slowly rolls off the lander, and onto the surface of Mars, once Pathfinder scientists determine it is safe to do so. http://photojournal.jpl.nasa.gov/catalog/PIA00614

Cars on Mars

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.

2002-01-01

Mars is one of the most fascinating planets in the solar system, featuring an atmosphere, water, and enormous volcanoes and canyons. The Mars Pathfinder, Global Surveyor, and Odyssey missions mark the first wave of the Planet Earth's coming invasion of the red planet, changing our views of the past and future of the planet and the possibilities of life. Scientist and science-fiction writer Geoffrey A. Landis will present experiences on the Pathfinder mission, the challenges of using solar power on the surface of Mars, and present future missions to Mars such as the upcoming Mars Twin Rovers, which will launch two highly-capable vehicles in 2003 to explore the surface of Mars.

Imager for Mars Pathfinder (IMP) image calibration

USGS Publications Warehouse

Reid, R.J.; Smith, P.H.; Lemmon, M.; Tanner, R.; Burkland, M.; Wegryn, E.; Weinberg, J.; Marcialis, R.; Britt, D.T.; Thomas, N.; Kramm, R.; Dummel, A.; Crowe, D.; Bos, B.J.; Bell, J.F.; Rueffer, P.; Gliem, F.; Johnson, J. R.; Maki, J.N.; Herkenhoff, K. E.; Singer, Robert B.

1999-01-01

The Imager for Mars Pathfinder returned over 16,000 high-quality images from the surface of Mars. The camera was well-calibrated in the laboratory, with <5% radiometric uncertainty. The photometric properties of two radiometric targets were also measured with 3% uncertainty. Several data sets acquired during the cruise and on Mars confirm that the system operated nominally throughout the course of the mission. Image calibration algorithms were developed for landed operations to correct instrumental sources of noise and to calibrate images relative to observations of the radiometric targets. The uncertainties associated with these algorithms as well as current improvements to image calibration are discussed. Copyright 1999 by the American Geophysical Union.

Making a home in space

NASA Technical Reports Server (NTRS)

Aaron, John; Gabris, Edward A.; Sulzman, Frank M.; Connors, Mary M.; Pilcher, Carl

1989-01-01

NASA's Office of Aeronautics and Space Technology has undertaken a series of manned space presence-development efforts under the aegis of the Civil Space Technology Initiative (CSTI) and Project Pathfinder. Typical of these CSTI efforts is the Aeroassist Flight Experiment, which will demonstrate techniques suitable in aerobrake design for slow trajectories to Mars and for lunar mission return. Long-duration human operations in space are a major element of Pathfinder, giving attention to such problems as space radiation exposure effects that could be several orders of magnitude greater on interplanetary exploration missions than on typical Space Shuttle flights. Mars Observer and Lunar Observer orbital missions are planned as a steppingstone to manned planetary exploration.

Performance of the Primary Mirror Center-of-Curvature Optical Metrology System during Cryogenic Testing of the JWST Pathfinder Telescope

NASA Technical Reports Server (NTRS)

Hadaway, James B.; Wells, Conrad; Olczak, Gene; Waldman, Mark; Whitman, Tony; Cosentino, Joseph; Connolly, Mark; Chaney, David; Telfer, Randal

2016-01-01

The JWST primary mirror consists of 18 1.5 m hexagonal segments, each with 6-DoF and RoC adjustment. The telescope will be tested at its cryogenic operating temperature at Johnson Space Center. The testing will include center-of-curvature measurements of the PM, using the Center-of-Curvature Optical Assembly (COCOA) and the Absolute Distance Meter Assembly (ADMA). The performance of these metrology systems, including hardware, software, procedures, was assessed during two cryogenic tests at JSC, using the JWST Pathfinder telescope. This paper describes the test setup, the testing performed, and the resulting metrology system performance.

Mineralogy, Abundance, and Hydration State of Sulfates and Chlorides at the Mars Pathfinder Landing Site

NASA Technical Reports Server (NTRS)

Zolotov, M. Y.; Kuzmin, R. O.; Shock, E. L.

2004-01-01

Detection of elevated concentrations of S and Cl at the landing sites of Viking 1 and 2 [1], and Mars Pathfinder (MP) [2-5] reveals the presence of sulfates and chlorides in soil and rock samples [1-10]. These data are consistent with the findings of Ca sulfates and NaCl in Martian meteorites [11,12], and with Earth-based spectroscopic observations [13,14] tentatively indicating the presence of sulfates on Mars. Although the correlation of S and Mg in Viking and MP samples could reveal the occurrence of Mg sulfate [1-10], the mineralogy of sulfates and chlorides remains unclear.

Geologic Measurements using Rover Images: Lessons from Pathfinder with Application to Mars 2001

NASA Technical Reports Server (NTRS)

Bridges, N. T.; Haldemann, A. F. C.; Herkenhoff, K. E.

1999-01-01

The Pathfinder Sojourner rover successfully acquired images that provided important and exciting information on the geology of Mars. This included the documentation of rock textures, barchan dunes, soil crusts, wind tails, and ventifacts. It is expected that the Marie Curie rover cameras will also successfully return important information on landing site geology. Critical to a proper analysis of these images will be a rigorous determination of rover location and orientation. Here, the methods that were used to compute rover position for Sojourner image analysis are reviewed. Based on this experience, specific recommendations are made that should improve this process on the '01 mission.

Wheel Abrasion Experiment Metals Selection for Mars Pathfinder Mission

NASA Technical Reports Server (NTRS)

Hepp, Aloysius F.; Fatemi, Navid S.; Wilt, David M.; Ferguson, Dale C.; Hoffman, Richard; Hill, Maria M.; Kaloyeros, Alain E.

1996-01-01

A series of metals was examined for suitability for the Wheel Abrasion Experiment, one of ten microrover experiments of the Mars Pathfinder Mission. The seven candidate metals were: Ag, Al, Au, Cu, Ni, Pt, and W. Thin films of candidate metals from 0.1 to 1.0 micrometer thick were deposited on black anodized aluminum coupons by e-beam and resistive evaporation and chemical vapor deposition. Optical, corrosion, abrasion, and adhesion criteria were used to select Al, Ni, and Pt. A description is given of the deposition and testing of thin films, followed by a presentation of experimental data and a brief discussion of follow-on testing and flight qualification.

Mars Pathfinder flight system integration and test.

NASA Astrophysics Data System (ADS)

Muirhead, B. K.

This paper describes the system integration and test experiences, problems and lessons learned during the assembly, test and launch operations (ATLO) phase of the Mars Pathfinder flight system scheduled to land on the surface of Mars on July 4, 1997. The Mars Pathfinder spacecraft consists of three spacecraft systems: cruise stage, entry vehicle and lander. The cruise stage carries the entry and lander vehicles to Mars and is jettisoned prior to entry. The entry vehicle, including aeroshell, parachute and deceleration rockets, protects the lander during the direct entry and reduces its velocity from 7.6 to 0 km/s in stages during the 5 min entry sequence. The lander's touchdown is softened by airbags which are retracted once stopped on the surface. The lander then uprights itself, opens up fully and begins surface operations including deploying its camera and rover. This paper overviews the system design and the results of the system integration and test activities, including the entry, descent and landing subsystem elements. System test experiences including science instruments, the microrover, Sojourner, and software are discussed. The final qualification of the entry, descent and landing subsystems during this period is also discussed.

The Stratospheric Aerosol and Gas Experiment (SAGE) IV Pathfinder

NASA Astrophysics Data System (ADS)

Hill, C. A.; Damadeo, R. P.; Gasbarre, J. F.

2017-12-01

Stratospheric ozone has been the subject of observation and research for decades. Measurements from satellites provided data on the initial decline in the late 1970s and early 1980s that supported the adoption of the Montreal Protocol to current observations hinting at potential recovery. Adequate determination of that recovery requires continuous and, in the case of multiple instruments, overlapping data records. However, most current satellite systems are well beyond their expected lifetimes and thus, with only a few "younger" instruments available, we look towards the future of satellite observations of stratospheric ozone to develop the Stratospheric Aerosol and Gas Experiment (SAGE) IV Pathfinder. The SAGE IV Pathfinder project will develop and validate a technology demonstration that will pave the way for a future SAGE IV mission. Utilizing solar occultation imaging, SAGE IV will be capable of measuring ozone, aerosol, and other trace gas species with the same quality as previous SAGE instruments but with greatly improved pointing knowledge. Furthermore, current technological advancements allow SAGE IV to fit within a CubeSat framework and make use of commercial hardware, significantly reducing the size and cost when compared with traditional missions and enabling sustainability of future measurements.

The Radiative Effects of Martian Water Ice Clouds on the Local Atmospheric Temperature Profile

NASA Technical Reports Server (NTRS)

Colaprete, Anthony; Toon, Owen B.

2000-01-01

Mars Pathfinder made numerous discoveries, one of which was a deep temperature inversion that extended from about 15 km down to 8 km above the surface. It has been suggested by Haberle et al. (1999. J. Geophys. Res. 104, 8957-8974.) that radiative cooling by a water ice cloud may generate such an inversion. Clouds can strongly affect the local air temperature due to their ability to radiate efficiently in the infrared and due to the low air mass of the martian atmosphere, which allows the temperature to change during the relatively short lifetime of a cloud. We utilize a time-dependent microphysical aerosol model coupled to a radiative--convective model to explore the effects water ice clouds have on the local martian temperature profile. We constrain the dust and water vapor abundance using data from the Viking Missions and Mars Pathfinder. Water t ice clouds with visible optical depths of r > 0.1 form readily in these simulations. These clouds alter the local air temperature directly, through infrared cooling, and indirectly, by redistributing atmospheric dust. With this model we are able to reproduce the temperature inversions observed by Mars Pathfinder and Mars Global t Surveyor 2000 Academic Press

Windblown Dunes and Ripples

NASA Technical Reports Server (NTRS)

2003-01-01

MGS MOC Release No. MOC2-411, 4 July 2003

July 4, 2003, is the 6th anniversary of the Mars Pathfinder landing. One of the elements carried to the red planet by Pathfinder was the Wind Sock Experiment. This project was designed to measure wind activity by taking pictures of three aluminum 'wind socks.' While the winds at the Mars Pathfinder site did not blow particularly strong during the course of that mission, dust storms seen from orbit and Earth-based telescopes attest to the fact that wind is a major force of change on the dry, desert surface of Mars today. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) narrow angle image shows dark sand dunes and lighter-toned ripples trapped among the mountainous central peak of an old impact crater in Terra Tyrrhena near 13.9oS, 246.7oW. The dune slip faces--the steepest slope on the larger dunes--indicate sand transport is from the top/upper left toward the bottom/lower right. North is toward the top/upper right; the picture is 3 km (1.9 mi) across. Sunlight illuminates the scene from the upper left. This picture was obtained in April 2003.

PathfinderTURB: an automatic boundary layer algorithm. Development, validation and application to study the impact on in situ measurements at the Jungfraujoch

NASA Astrophysics Data System (ADS)

Poltera, Yann; Martucci, Giovanni; Collaud Coen, Martine; Hervo, Maxime; Emmenegger, Lukas; Henne, Stephan; Brunner, Dominik; Haefele, Alexander

2017-08-01

We present the development of the PathfinderTURB algorithm for the analysis of ceilometer backscatter data and the real-time detection of the vertical structure of the planetary boundary layer. Two aerosol layer heights are retrieved by PathfinderTURB: the convective boundary layer (CBL) and the continuous aerosol layer (CAL). PathfinderTURB combines the strengths of gradient- and variance-based methods and addresses the layer attribution problem by adopting a geodesic approach. The algorithm has been applied to 1 year of data measured by two ceilometers of type CHM15k, one operated at the Aerological Observatory of Payerne (491 m a.s.l.) on the Swiss plateau and one at the Kleine Scheidegg (2061 m a.s.l.) in the Swiss Alps. The retrieval of the CBL has been validated at Payerne using two reference methods: (1) manual detections of the CBL height performed by human experts using the ceilometer backscatter data; (2) values of CBL heights calculated using the Richardson's method from co-located radio sounding data. We found average biases as small as 27 m (53 m) with respect to reference method 1 (method 2). Based on the excellent agreement between the two reference methods, PathfinderTURB has been applied to the ceilometer data at the mountainous site of the Kleine Scheidegg for the period September 2014 to November 2015. At this site, the CHM15k is operated in a tilted configuration at 71° zenith angle to probe the atmosphere next to the Sphinx Observatory (3580 m a.s.l.) on the Jungfraujoch (JFJ). The analysis of the retrieved layers led to the following results: the CAL reaches the JFJ 41 % of the time in summer and 21 % of the time in winter for a total of 97 days during the two seasons. The season-averaged daily cycles show that the CBL height reaches the JFJ only during short periods (4 % of the time), but on 20 individual days in summer and never during winter. During summer in particular, the CBL and the CAL modify the air sampled in situ at JFJ, resulting in an unequivocal dependence of the measured absorption coefficient on the height of both layers. This highlights the relevance of retrieving the height of CAL and CBL automatically at the JFJ.

Dynamic Control System Mode Performance of the Space Technology-7 Disturbance Reduction System

NASA Technical Reports Server (NTRS)

O'Donnell, James R., Jr.; Hsu, Oscar; Maghami, Peiman

2017-01-01

The Space Technology-7 (ST-7) Disturbance Reduction System (DRS) is an experiment package aboard the European Space Agency (ESA) LISA Pathfinder spacecraft, launched on December 3, 2015. DRS consists of three primary components: Colloidal MicroNewton Thrusters (CMNTs), an Integrated Avionics Unit (IAU), and flight-software implementing the Command and Data Handling (C&DH) and Dynamic Control System (DCS) algorithms. The CMNTs were designed to provide thrust from 5 to 30 micro Newton, with thrust controllability and resolution of 0.1 micro Newton and thrust noise of 0.1 micro Newton/(square root of (Hz)) in the measurement band from 1-30 mHz. The IAU hosts the C&DH and DCS flight software, as well as interfaces with both the CMNT electronics and the LISA Pathfinder spacecraft. When in control, the DCS uses star tracker attitude data and capacitive or optically-measured position and attitude information from LISA Pathfinder and the LISA Technology Package (LTP) to control the attitude and position of the spacecraft and the two test masses inside the LTP. After completion of the nominal ESA LISA Pathfinder mission, the DRS experiment was commissioned followed by its nominal mission. DRS operations extended over the next five months, interspersed with station keeping, anomaly resolution, and periods where control was handed back to LISA Pathfinder for them to conduct further experiments. The primary DRS mission ended on December 6, 2016, with the experiment meeting all of its Level 1 requirements. The DCS, developed at the NASA Goddard Space Flight Center, consists of five spacecraft control modes and six test mass control modes, combined into six 'DRS Mission Modes'. Attitude Control and Zero-G were primarily used to control the spacecraft during initial handover and during many of the CMNT characterization experiments. The other Mission Modes, Drag Free Low Force, 18-DOF Transitional, and 18-DOF, were used to provide drag-free control of the spacecraft about the test masses. This paper will discuss the performance of these DCS spacecraft and test mass control modes. Flight data will be shown from each mode throughout the mission, both from nominal operations and during various flight experiments. The DCS team also made some changes to controller, filter, and limit parameters during operations; the motivation and results of these changes will be shown and discussed.

Fission Surface Power Systems (FSPS) Project Final Report for the Exploration Technology Development Program (ETDP): Fission Surface Power, Transition Face to Face

NASA Technical Reports Server (NTRS)

Palac, Donald T.

2011-01-01

The Fission Surface Power Systems Project became part of the ETDP on October 1, 2008. Its goal was to demonstrate fission power system technology readiness in an operationally relevant environment, while providing data on fission system characteristics pertinent to the use of a fission power system on planetary surfaces. During fiscal years 08 to 10, the FSPS project activities were dominated by hardware demonstrations of component technologies, to verify their readiness for inclusion in the fission surface power system. These Pathfinders demonstrated multi-kWe Stirling power conversion operating with heat delivered via liquid metal NaK, composite Ti/H2O heat pipe radiator panel operations at 400 K input water temperature, no-moving-part electromagnetic liquid metal pump operation with NaK at flight-like temperatures, and subscale performance of an electric resistance reactor simulator capable of reproducing characteristics of a nuclear reactor for the purpose of system-level testing, and a longer list of component technologies included in the attached report. Based on the successful conclusion of Pathfinder testing, work began in 2010 on design and development of the Technology Demonstration Unit (TDU), a full-scale 1/4 power system-level non-nuclear assembly of a reactor simulator, power conversion, heat rejection, instrumentation and controls, and power management and distribution. The TDU will be developed and fabricated during fiscal years 11 and 12, culminating in initial testing with water cooling replacing the heat rejection system in 2012, and complete testing of the full TDU by the end of 2014. Due to its importance for Mars exploration, potential applicability to missions preceding Mars missions, and readiness for an early system-level demonstration, the Enabling Technology Development and Demonstration program is currently planning to continue the project as the Fission Power Systems project, including emphasis on the TDU completion and testing.

NASA Fastrac Engine Gas Generator Component Test Program and Results

NASA Technical Reports Server (NTRS)

Dennis, Henry J., Jr.; Sanders, T.

2000-01-01

Low cost access to space has been a long-time goal of the National Aeronautics and Space Administration (NASA). The Fastrac engine program was begun at NASA's Marshall Space Flight Center to develop a 60,000-pound (60K) thrust, liquid oxygen/hydrocarbon (LOX/RP), gas generator-cycle booster engine for a fraction of the cost of similar engines in existence. To achieve this goal, off-the-shelf components and readily available materials and processes would have to be used. This paper will present the Fastrac gas generator (GG) design and the component level hot-fire test program and results. The Fastrac GG is a simple, 4-piece design that uses well-defined materials and processes for fabrication. Thirty-seven component level hot-fire tests were conducted at MSFC's component test stand #116 (TS116) during 1997 and 1998. The GG was operated at all expected operating ranges of the Fastrac engine. Some minor design changes were required to successfully complete the test program as development issues arose during the testing. The test program data results and conclusions determined that the Fastrac GG design was well on the way to meeting the requirements of NASA's X-34 Pathfinder Program that chose the Fastrac engine as its main propulsion system.

Community-Driven Support in the Hydrologic Sciences through Data, Education and Outreach

NASA Astrophysics Data System (ADS)

Clark, E.

2015-12-01

The Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) is a non-profit funded by the National Science Foundation to support water science research and education. As outlined in the CUAHSI Education and Outreach Strategy, our objectives are: 1) helping the member institutions communicate water science; 2) cross-disciplinary water education; 3) dissemination of research; 4) place-based water education using data services; and 5) broadening participation. Through the CUAHSI Water Data Center, online tools and resources are available to discover, download, and analyze multiple time-series water datasets across various parameters. CUAHSI supports novel graduate student research through the Pathfinder Fellowship program which has enhanced the interdisciplinary breadth of early-career research. Public outreach through the Let's Talk About Water film symposium and cyberseminar programs have proven effective in distributing research, leading to more recent development of virtual training workshops. By refining and building upon CUAHSI's existing programs, new training opportunities, collaborative projects, and community-building activities for the hydrologic sciences have come to fruition, such as the recent National Flood Interoperability Experiment with the NOAA's National Water Center.

Community-Driven Support in the Hydrologic Sciences through Data, Education and Outreach

NASA Astrophysics Data System (ADS)

Cox, P. R.

2014-12-01

The Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) is a non-profit funded by the National Science Foundation to support water science research and education. As outlined in the CUAHSI Education and Outreach Strategy, our objectives are: 1) helping the member institutions communicate water science; 2) cross-disciplinary water education; 3) dissemination of research; 4) place-based water education using data services; and 5) broadening participation. Through the CUAHSI Water Data Center, online tools and resources are available to discover, download, and analyze multiple time-series water datasets across various parameters. CUAHSI supports novel graduate student research through the Pathfinder Fellowship program which has enhanced the interdisciplinary breadth of early-career research. Public outreach through the Let's Talk About Water film symposium and cyberseminar programs have proven effective in distributing research, leading to more recent development of virtual training workshops. By refining and building upon CUAHSI's existing programs, new training opportunities, collaborative projects, and community-building activities for the hydrologic sciences have come to fruition, such as the recent National Flood Interoperability Experiment with the NOAA's National Water Center.

SRB Processing Facilities Media Event

NASA Image and Video Library

2016-03-01

Members of the news media view the high bay inside the Rotation, Processing and Surge Facility (RPSF) at NASA’s Kennedy Space Center in Florida. Kerry Chreist, with Jacobs Engineering on the Test and Operations Support Contract, explains the various test stands and how they will be used to prepare booster segments for NASA’s Space Launch System (SLS) rocket. In the far corner, in the vertical position, is one of two pathfinders, or test versions, of solid rocket booster segments for the SLS rocket. The Ground Systems Development and Operations Program and Jacobs are preparing the booster segments, which are inert, for a series of lifts, moves and stacking operations to prepare for Exploration Mission-1, deep-space missions and the journey to Mars.

Testing the Gossamer Albatross II

NASA Technical Reports Server (NTRS)

1980-01-01

The Gossamer Albatross II is seen here during a test flight at NASA's Dryden Flight Research Center, Edwards, California. The original Gossamer Albatross is best known for completing the first completely human powered flight across the English Channel on June 12, 1979. The Albatross II was the backup craft for the Channel flight. It was fitted with a small battery-powered electric motor and flight instruments for the NASA research program in low-speed flight. NASA completed its flight testing of the Gossamer Albatross II and began analysis of the results in April, 1980. During the six week program, 17 actual data gathering flights and 10 other flights were flown here as part of the joint NASA Langley/Dryden flight research program. The lightweight craft, carrying a miniaturized instrumentation system, was flown in three configurations; using human power, with a small electric motor, and towed with the propeller removed. Results from the program contributed to data on the unusual aerodynamic, performance, stability, and control characteristics of large, lightweight aircraft that fly at slow speeds for application to future high altitude aircraft. The Albatross' design and research data contributed to numerous later high altitude projects, including the Pathfinder.

Assembling the Gossamer Albatross II in hangar

NASA Technical Reports Server (NTRS)

1980-01-01

The Gossamer Albatross II is seen here being assembled in a hangar at the Dryden Flight Research Center, Edwards, California. The original Gossamer Albatross is best known for completing the first completely human powered flight across the English Channel on June 12, 1979. The Albatross II was the backup craft for the Channel flight. The aircraft was fitted with a small battery-powered electric motor and flight instruments for the NASA research program in low-speed flight. NASA completed its flight testing of the Gossamer Albatross II and began analysis of the results in April, 1980. During the six week program, 17 actual data gathering flights and 10 other flights were flown here as part of the joint NASA Langley/Dryden flight research program. The lightweight craft, carrying a miniaturized instrumentation system, was flown in three configurations; using human power, with a small electric motor, and towed with the propeller removed. Results from the program contributed to data on the unusual aerodynamic, performance, stability, and control characteristics of large, lightweight aircraft that fly at slow speeds for application to future high altitude aircraft. The Albatross' design and research data contributed to numerous later high altitude projects, including the Pathfinder.

Pathfinder Technologies Specialist, X-37

NASA Technical Reports Server (NTRS)

French, James R.

2001-01-01

The X-37 is a technology demonstrator sponsored by NASA. It includes a number of experiments both imbedded (i.e., essential aspects of the vehicle) and separate. The technologies demonstrated will be useful in future operational versions as well as having broad applications to other programs. Mr. James R. French, of JRF Engineering Services and as a consultant to SAIC, has provided technical support to the X-37 NASA Program office since the beginning of the program. In providing this service, Mr. French has maintained close contact with the Boeing Seal Beach and Rocketdyne technical teams via telephone, e-mail, and periodic visits. His interfaces were primarily with the working engineers in order to provide NASA sponsors with a different view than that achieved through management channels. Mr. French's periodic and highly detailed technical reports were submitted to NASA and SAIC (Science Applications International Corporation) on a weekly/monthly basis. These reports addressed a wide spectrum of programmatic and technical interests related to the X-37 Program including vehicle design, flight sciences, propulsion, thermal protection, Guidance Navigation & Control (GN&C), structures, and operations. This deliverable is presented as a consolidation of the twelve monthly reports submitted during the Contract's Option Year,

Terrain Modelling for Immersive Visualization for the Mars Exploration Rovers

NASA Technical Reports Server (NTRS)

Wright, J.; Hartman, F.; Cooper, B.; Maxwell, S.; Yen, J.; Morrison, J.

2004-01-01

Immersive environments are being used to support mission operations at the Jet Propulsion Laboratory. This technology contributed to the Mars Pathfinder Mission in planning sorties for the Sojourner rover and is being used for the Mars Exploration Rover (MER) missions. The stereo imagery captured by the rovers is used to create 3D terrain models, which can be viewed from any angle, to provide a powerful and information rich immersive visualization experience. These technologies contributed heavily to both the mission success and the phenomenal level of public outreach achieved by Mars Pathfinder and MER. This paper will review the utilization of terrain modelling for immersive environments in support of MER.

Sojourner View of Yogi

NASA Image and Video Library

1997-11-04

This Sojourner image, taken on Sol 70, shows rocks and rover-disturbed soil. Cleats on Sojourner's left front wheel are seen at lower left. The large rock in the distance is "Yogi." Much of Yogi visible in this image cannot be seen from the perspective of the Pathfinder lander. Sojourner spent 83 days of a planned seven-day mission exploring the Martian terrain, acquiring images, and taking chemical, atmospheric and other measurements. The final data transmission received from Pathfinder was at 10:23 UTC on September 27, 1997. Although mission managers tried to restore full communications during the following five months, the successful mission was terminated on March 10, 1998. http://photojournal.jpl.nasa.gov/catalog/PIA00998

Studies of MGS TES and MPF MET Data

NASA Technical Reports Server (NTRS)

Barnes, Jeff R.

2003-01-01

The work supported by this grant was divided into two broad areas: (1) mesoscale modeling of atmospheric circulations and analyses of Pathfinder, Viking, and other Mars data, and (2) analyses of MGS TES temperature data. The mesoscale modeling began with the development of a suitable Mars mesoscale model based upon the terrestrial MM5 model, which was then applied to the simulation of the meteorological observations at the Pathfinder and Viking Lander 1 sites during northern summer. This extended study served a dual purpose: to validate the new mesoscale model with the best of the available in-situ data, and to use the model to aid in the interpretation of the surface meteorological data.

Gravitational Reference Sensor Front-End Electronics Simulator for LISA

NASA Astrophysics Data System (ADS)

Meshksar, Neda; Ferraioli, Luigi; Mance, Davor; ten Pierick, Jan; Zweifel, Peter; Giardini, Domenico; ">LISA Pathfinder colaboration, Pathfinder autonomous rendezvous and docking project

NASA Technical Reports Server (NTRS)

Lamkin, Stephen (Editor); Mccandless, Wayne (Editor)

1990-01-01

Capabilities are being developed and demonstrated to support manned and unmanned vehicle operations in lunar and planetary orbits. In this initial phase, primary emphasis is placed on definition of the system requirements for candidate Pathfinder mission applications and correlation of these system-level requirements with specific requirements. The FY-89 activities detailed are best characterized as foundation building. The majority of the efforts were dedicated to assessing the current state of the art, identifying desired elaborations and expansions to this level of development and charting a course that will realize the desired objectives in the future. Efforts are detailed across all work packages in developing those requirements and tools needed to test, refine, and validate basic autonomous rendezvous and docking elements.

Rock Statistics at the Mars Pathfinder Landing Site, Roughness and Roving on Mars

NASA Technical Reports Server (NTRS)

Haldemann, A. F. C.; Bridges, N. T.; Anderson, R. C.; Golombek, M. P.

1999-01-01

Several rock counts have been carried out at the Mars Pathfinder landing site producing consistent statistics of rock coverage and size-frequency distributions. These rock statistics provide a primary element of "ground truth" for anchoring remote sensing information used to pick the Pathfinder, and future, landing sites. The observed rock population statistics should also be consistent with the emplacement and alteration processes postulated to govern the landing site landscape. The rock population databases can however be used in ways that go beyond the calculation of cumulative number and cumulative area distributions versus rock diameter and height. Since the spatial parameters measured to characterize each rock are determined with stereo image pairs, the rock database serves as a subset of the full landing site digital terrain model (DTM). Insofar as a rock count can be carried out in a speedier, albeit coarser, manner than the full DTM analysis, rock counting offers several operational and scientific products in the near term. Quantitative rock mapping adds further information to the geomorphic study of the landing site, and can also be used for rover traverse planning. Statistical analysis of the surface roughness using the rock count proxy DTM is sufficiently accurate when compared to the full DTM to compare with radar remote sensing roughness measures, and with rover traverse profiles.

Slits are chemorepellents endogenous to hypothalamus and steer thalamocortical axons into ventral telencephalon.

PubMed

Braisted, Janet E; Ringstedt, Thomas; O'Leary, Dennis D M

2009-07-01

Thalamocortical axons (TCAs) originate in dorsal thalamus, extend ventrally along the lateral thalamic surface, and as they approach hypothalamus make a lateral turn into ventral telencephalon. In vitro studies show that hypothalamus releases a chemorepellent for TCAs, and analyses of knockout mice indicate that Slit chemorepellents and their receptor Robo2 influence TCA pathfinding. We show that Slit chemorepellents are the hypothalamic chemorepellent and act through Robos to steer TCAs into ventral telencephalon. During TCA pathfinding, Slit1 and Slit2 are expressed in hypothalamus and ventral thalamus and Robo1 and Robo2 are expressed in dorsal thalamus. In collagen gel cocultures of dorsal thalamus and Slit2-expressing cells, axon number and length are decreased on the explant side facing Slit2-expressing cells, overall axon outgrowth is diminished, and axons turn away from the Slit2-expressing cells. Thus, Slit2 is an inhibitor and chemorepellent for dorsal thalamic axons. Collagen gel cocultures of dorsal thalamus with sections of live diencephalon, with and without the hypothalamus portion overlaid with Robo2-fc-expressing cells to block Slit function, identify Slits as the hypothalamic chemorepellent. Thus, Slits are chemorepellents for TCAs endogenous to hypothalamus and steer TCAs from diencephalon into ventral telencephalon, a critical pathfinding event defective in Slit and Robo2 mutant mice.

Mars Pathfinder mission operations concepts

NASA Technical Reports Server (NTRS)

Sturms, Francis M., Jr.; Dias, William C.; Nakata, Albert Y.; Tai, Wallace S.

1994-01-01

The Mars Pathfinder Project plans a December 1996 launch of a single spacecraft. After jettisoning a cruise stage, an entry body containing a lander and microrover will directly enter the Mars atmosphere and parachute to a hard landing near the sub-solar latitude of 15 degrees North in July 1997. Primary surface operations last for 30 days. Cost estimates for Pathfinder ground systems development and operations are not only lower in absolute dollars, but also are a lower percentage of total project costs than in past planetary missions. Operations teams will be smaller and fewer than typical flight projects. Operations scenarios have been developed early in the project and are being used to guide operations implementation and flight system design. Recovery of key engineering data from entry, descent, and landing is a top mission priority. These data will be recorded for playback after landing. Real-time tracking of a modified carrier signal through this phase can provide important insight into the spacecraft performance during entry, descent, and landing in the event recorded data is never recovered. Surface scenarios are dominated by microrover activity and lander imaging during 7 hours of the Mars day from 0700 to 1400 local solar time. Efficient uplink and downlink processes have been designed to command the lander and microrover each Mars day.

Drag-Free Performance of the ST7 Disturbance Reduction System Flight Experiment on the LISA Pathfinder

NASA Technical Reports Server (NTRS)

Maghami, Peiman; O'Donnell, James, Jr.; Hsu, Oscar; Ziemer, John; Dunn, Charles

2017-01-01

The Space Technology-7 Disturbance Reduction System (DRS) is an experiment package aboard the European Space Agency (ESA) LISA Pathfinder spacecraft. LISA Pathfinder launched from Kourou, French Guiana on December 3, 2015. The DRS is tasked to validate two specific technologies: colloidal micro-Newton thrusters (CMNT) to provide low-noise control capability of the spacecraft, and drag-free control flight. This validation is performed using highly sensitive drag-free sensors, which are provided by the LISA Technology Package of the European Space Agency. The Disturbance Reduction System is required to maintain the spacecrafts position with respect to a free-floating test mass to better than 10nmHz, along its sensitive axis (axis in optical metrology). It also has a goal of limiting the residual accelerations of any of the two test masses to below 30 (1 + [f3 mHz]) fmsHz, over the frequency range of 1 to 30 mHz.This paper briefly describes the design and the expected on-orbit performance of the control system for the two modes wherein the drag-free performance requirements are verified. The on-orbit performance of these modes are then compared to the requirements, as well as to the expected performance, and discussed.

Visualizing Mars Using Virtual Reality: A State of the Art Mapping Technique Used on Mars Pathfinder

NASA Technical Reports Server (NTRS)

Stoker, C.; Zbinden, E.; Blackmon, T.; Nguyen, L.

1999-01-01

We describe an interactive terrain visualization system which rapidly generates and interactively displays photorealistic three-dimensional (3-D) models produced from stereo images. This product, first demonstrated in Mars Pathfinder, is interactive, 3-D, and can be viewed in an immersive display which qualifies it for the name Virtual Reality (VR). The use of this technology on Mars Pathfinder was the first use of VR for geologic analysis. A primary benefit of using VR to display geologic information is that it provides an improved perception of depth and spatial layout of the remote site. The VR aspect of the display allows an operator to move freely in the environment, unconstrained by the physical limitations of the perspective from which the data were acquired. Virtual Reality offers a way to archive and retrieve information in a way that is intuitively obvious. Combining VR models with stereo display systems can give the user a sense of presence at the remote location. The capability, to interactively perform measurements from within the VR model offers unprecedented ease in performing operations that are normally time consuming and difficult using other techniques. Thus, Virtual Reality can be a powerful a cartographic tool. Additional information is contained in the original extended abstract.

The Australian SKA Pathfinder: project update and initial operations

NASA Astrophysics Data System (ADS)

Schinckel, Antony E. T.; Bock, Douglas C.-J.

2016-08-01

The Australian Square Kilometre Array Pathfinder (ASKAP) will be the fastest dedicated cm-wave survey telescope, and will consist of 36 12-meter 3-axis antennas, each with a large chequerboard phased array feed (PAF) receiver operating between 0.7 and 1.8 GHz, and digital beamforming prior to correlation. The large raw data rates involved ( 100 Tb/sec), and the need to do pipeline processing, has led to the antenna incorporating a third axis to fix the parallactic angle with respect to the entire optical system (blockages and phased array feed). It also results in innovative technical solutions to the data transport and processing issues. ASKAP is located at the Murchison Radio-astronomy Observatory (MRO), a new observatory developed for the Square Kilometre Array (SKA), 315 kilometres north-east of Geraldton, Western Australia. The MRO also hosts the SKA low frequency pathfinder instrument, the Murchison Widefield Array and will host the initial low frequency instrument of the SKA, SKA1-Low. Commissioning of ASKAP using six antennas equipped with first-generation PAFs is now complete and installation of second-generation PAFs and digital systems is underway. In this paper we review technical progress and commissioning to date, and refer the reader to relevant technical and scientific publications.

Observations at the Mars Pathfinder site: Do they provide "unequivocal" evidence of catastrophic flooding?

USGS Publications Warehouse

Chapman, M.G.; Kargel, J.S.

1999-01-01

After Mars Pathfinder landed at the mouth of Ares Vallis, a large channel that drains into the Chryse Planitia basin, the mission reports unanimously supported the interpretation that the lander site is the locus of catastrophic flooding by noting that all aspects of the scene are consistent with this interpretation. However, alternatives cannot be ruled out by any site observations, as all aspects of the scene are equally consistent with other interpretations of origin, namely, ice and mass-flow processes subsequently modified by wind erosion. The authors discuss alternative explanations for the geologic history of the channel based on a regional view of the circum-Chryse channels from Viking images (our best broad-scale information to date) and the local view from the recent Pathfinder landing site. Mega-indicators of channel origin, the regional geomorphology, geology, and planetary climatic conditions, taken together suggest some combination of flood, mass flow, glacial, and eolian processes. The macro-indicators of channel origin (sedimentologic) are also not indicative of one process of emplacement, either as single criteria or taken cumulatively. Finally, the micro-indicators of channel origin (geochemical and mineralogic composition) do not provide very tight constraints on the deposits' possible origins other than that water was in some way involved.

A New Method for Analyzing Near-Field Faraday Probe Data in Hall Thrusters

NASA Technical Reports Server (NTRS)

Huang, Wensheng; Shastry, Rohit; Herman, Daniel A.; Soulas, George C.; Kamhawi, Hani

2013-01-01

This paper presents a new method for analyzing near-field Faraday probe data obtained from Hall thrusters. Traditional methods spawned from far-field Faraday probe analysis rely on assumptions that are not applicable to near-field Faraday probe data. In particular, arbitrary choices for the point of origin and limits of integration have made interpretation of the results difficult. The new method, called iterative pathfinding, uses the evolution of the near-field plume with distance to provide feedback for determining the location of the point of origin. Although still susceptible to the choice of integration limits, this method presents a systematic approach to determining the origin point for calculating the divergence angle. The iterative pathfinding method is applied to near-field Faraday probe data taken in a previous study from the NASA-300M and NASA-457Mv2 Hall thrusters. Since these two thrusters use centrally mounted cathodes the current density associated with the cathode plume is removed before applying iterative pathfinding. A procedure is presented for removing the cathode plume. The results of the analysis are compared to far-field probe analysis results. This paper ends with checks on the validity of the new method and discussions on the implications of the results.

A New Method for Analyzing Near-Field Faraday Probe Data in Hall Thrusters

NASA Technical Reports Server (NTRS)

Huang, Wensheng; Shastry, Rohit; Herman, Daniel A.; Soulas, George C.; Kamhawi, Hani

2013-01-01

This paper presents a new method for analyzing near-field Faraday probe data obtained from Hall thrusters. Traditional methods spawned from far-field Faraday probe analysis rely on assumptions that are not applicable to near-field Faraday probe data. In particular, arbitrary choices for the point of origin and limits of integration have made interpretation of the results difficult. The new method, called iterative pathfinding, uses the evolution of the near-field plume with distance to provide feedback for determining the location of the point of origin. Although still susceptible to the choice of integration limits, this method presents a systematic approach to determining the origin point for calculating the divergence angle. The iterative pathfinding method is applied to near-field Faraday probe data taken in a previous study from the NASA-300M and NASA-457Mv2 Hall thrusters. Since these two thrusters use centrally mounted cathodes, the current density associated with the cathode plume is removed before applying iterative pathfinding. A procedure is presented for removing the cathode plume. The results of the analysis are compared to far-field probe analysis results. This paper ends with checks on the validity of the new method and discussions on the implications of the results.

The Mars Pathfinder Mission

NASA Astrophysics Data System (ADS)

Golombek, M. P.

1996-09-01

The Mars Pathfinder mission is a Discovery class mission that will place a small lander and rover on the surface of Mars on July 4, 1997. The Pathfinder flight system is a single small lander, packaged within an aeroshell and back cover with a back-pack-style cruise stage. The vehicle will be launched, fly independently to Mars, and enter the atmosphere directly on approach behind the aeroshell. The vehicle is slowed by a parachute and 3 small solid rockets before landing on inflated airbags. Petals of a small tetrahedron shaped lander open up, to right the vehicle. The lander is solar powered with batteries and will operate on the surface for up to a year, downlinking data on a high-gain antenna. Pathfinder will be the first mission to use a rover, with 3 imagers and an alpha proton X-ray spectrometer, to characterize the rocks and soils in a landing area over hundreds of square meters on Mars, which will provide a calibration point or "ground truth" for orbital remote sensing observations. The rover (includes a series of technology experiments), the instruments (including a stereo multispectral surface imager on a pop up mast and an atmospheric structure instrument-surface meteorology package) and the telemetry system will allow investigations of: the surface morphology and geology at meter scale, the petrology and geochemistry of rocks and soils, the magnetic properties of dust, soil mechanics and properties, a variety of atmospheric investigations and the rotational and orbital dynamics of Mars. Landing downstream from the mouth of a giant catastrophic outflow channel, Ares Vallis, offers the potential of identifying and analyzing a wide variety of crustal materials, from the ancient heavily cratered terrain, intermediate-aged ridged plains and reworked channel deposits, thus allowing first-order scientific investigations of the early differentiation and evolution of the crust, the development of weathering products and early environments and conditions on Mars.

Laser modulator for LISA pathfinder

NASA Astrophysics Data System (ADS)

Voland, C.; Lund, G.; Coppoolse, W.; Crosby, P.; Stadler, M.; Kudielka, K.; Özkan, C.

2017-11-01

LISA Pathfinder is an ESA experiment to demonstrate the key technologies needed for the LISA mission to detect gravitational waves in space. The LISA Pathfinder spacecraft represents one arm of the LISA interferometer, containing an optical metrology system and two proof masses as inertial references for the drag-free control system. The LISA Pathfinder payload consists of two drag-free floating test masses located in the inertial sensors with their control electronics and an optical metrology subsystem. The optical metrology subsystem monitors the movement of both test masses relative to each other and to the spacecraft with very high sensitivity and resolution. This is achieved with a heterodyne Mach- Zehnder interferometer. This interferometer requires as input two coherent laser beams with a heterodyne frequency difference of a few kHz. To generate the two laser beams with a heterodyne frequency difference a Nd:YAG laser is used together with the Laser Modulator. The Nd:YAG laser generates a single coherent laser signal at a wavelength of 1064nm which is fibre coupled to the Laser Modulator. The Laser Modulator then generates the two optical beams with the required heterodyne frequency offset. In addition, the Laser Modulator is required to perform laser amplitude stabilization and optical path difference control for the two optical signals. The Laser Modulator consists of an optical unit - the LMU - and RF synthesiser, power amplification and control electronics. These electronics are all housed in the Laser Modulator Electronics (LME). The LMU has four primary functions: • Splitting of the input laser beam into two paths for later superposition in the interferometer. • Applying different frequency shifts to each of the beams. • Providing amplitude modulation control to each of the beams. • Providing active control of the optical path length difference between the two optical paths. The present paper describes the design and performance of the LMU together with a summary of the results of the Laser Modulator engineering model test campaign.

How to Put Wellness on the Prescription Pad: Recommendations

PubMed Central

Fortin, P.R.

2008-01-01

The Integrating Wellness into Cancer Care conference was held at the University of Toronto, October 4–5, 2007, and was dedicated to the memory of the late Dr. Véronique Benk. This article summarizes the workshops at that conference. The notion of wellness and an integrated approach should be introduced from the outset as part of the cancer patient’s management. Having wellness as part of the treatment sets a standard for taking care of the patient’s emotional, spiritual, physical, and nutritional needs, and for providing information on complementary therapies. A focus on holistic supportive care during treatment and survivorship is important. The whole medical team should support an integrative program. Referral to an education program and one-to-one assessments by a point person such as an advanced nurse practitioner, a social worker, or a psychological counsellor with appropriate special training should be mandatory. The concept of a pathfinder or cancer guide was discussed. PMID:18769583

Big Crater as Viewed by Pathfinder Lander - Anaglyph

NASA Technical Reports Server (NTRS)

1997-01-01

The 'Big Crater' is actually a relatively small Martian crater to the southeast of the Mars Pathfinder landing site. It is 1500 meters (4900 feet) in diameter, or about the same size as Meteor Crater in Arizona. Superimposed on the rim of Big Crater (the central part of the rim as seen here) is a smaller crater nicknamed 'Rimshot Crater.' The distance to this smaller crater, and the nearest portion of the rim of Big Crater, is 2200 meters (7200 feet). To the right of Big Crater, south from the spacecraft, almost lost in the atmospheric dust 'haze,' is the large streamlined mountain nicknamed 'Far Knob.' This mountain is over 450 meters (1480 feet) tall, and is over 30 kilometers (19 miles) from the spacecraft. Another, smaller and closer knob, nicknamed 'Southeast Knob' can be seen as a triangular peak to the left of the flanks of the Big Crater rim. This knob is 21 kilometers (13 miles) southeast from the spacecraft.

The larger features visible in this scene - Big Crater, Far Knob, and Southeast Knob - were discovered on the first panoramas taken by the IMP camera on the 4th of July, 1997, and subsequently identified in Viking Orbiter images taken over 20 years ago. The scene includes rocky ridges and swales or 'hummocks' of flood debris that range from a few tens of meters away from the lander to the distance of South Twin Peak. The largest rock in the nearfield, just left of center in the foreground, nicknamed 'Otter', is about 1.5 meters (4.9 feet) long and 10 meters (33 feet) from the spacecraft.

This view of Big Crater was produced by combining 6 individual 'Superpan' scenes from the left and right eyes of the IMP camera. Each frame consists of 8 individual frames (left eye) and 7 frames (right eye) taken with different color filters that were enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution panchromatic frame that is sharper than an individual frame would be.

The anaglyph view of Big Crater was produced by combining the left and right eye mosaics (above) by assigning the left eye view to the red color plane and the right eye view to the green and blue color planes (cyan), to produce a stereo anaglyph mosaic. This mosaic can be viewed in 3-D on your computer monitor or in color print form by wearing red-blue 3-D glasses.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

Detection and Characterization of Micrometeoroid Impacts on LISA Pathfinder

NASA Astrophysics Data System (ADS)

Hourihane, S.; Littenberg, T.; Baker, J. G.; Pagane, N.; Slutsky, J. P.; Thorpe, J. I.

2017-12-01

LISA Pathfinder (LPF) was a joint ESA/NASA technology demonstration mission for the Laser Interferometer Space Antenna (LISA) gravitational wave observatory. LPF, the most sensitive accelerometer ever flown in space, was launched in December 2015 and successfully concluded its mission in July 2017. Due in part to LPFs success, LISA was selected by the European Space Agency for launch in the early 2030s. An ancillary benefit of LPFs capabilities made it a sensitive detector of micrometeoroid impacts. We report on the capabilities of LPF to detect and characterize impacts, and progress towards using those inferences to advance our understanding of the micrometeoroid environment in the solar system. In doing so, we assess the prospect of space-based gravitational wave observatories as micrometeoroid detection instruments.

Size Scales for Thermal Inhomogeneities in Mars' Atmosphere Surface Layer: Mars Pathfinder

NASA Technical Reports Server (NTRS)

Mihalov, John D.; Haberle, Robert M.; Seiff, Alvin; Murphy, James R.; Schofield, John T.; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

Atmospheric temperature measurement at three heights with thin wire thermocouples on the 1.1 m Mars Pathfinder meteorology must allow estimates of the integral scale of the atmospheric thermal turbulence during an 83 sol period that begins in the summer. The integral scale is a measure for regions of perturbations. In turbulent media that roughly characterizes locations where the perturbations are correlated. Excluding some to intervals with violent excursions of the mean temperatures, integral scale values are found that increase relatively rapidly from a few tenths meters or less near down to several meters by mid-morning. During mid-morning, the diurnal and shorter time scale wind direction variations often place the meteorology mast in the thermal wake of the Lander.

Mars 2024/2026 Pathfinder Mission: Mars Architectures, Systems, and Technologies for Exploration and Resources Project

NASA Technical Reports Server (NTRS)

Zeitlin, Nancy; Mueller, Robert; Muscatello, Anthony

2015-01-01

Integrate In Situ Resource Utilization (ISRU) sub-systems and examine advanced capabilities and technologies to verify Mars 2024 Forward architecture precursor pathfinder options: Integrated spacecraft/surface infrastructure fluid architecture: propulsion, power, life support center dot Power system feed and propellant scavenging from propulsion system center dot High quality oxygen for life support and EVA Fluid/cryogenic zero-loss transfer and long-term storage center dot Rapid depot-to-rover/spacecraft center dot Slow ISRU plant-to-ascent vehicle Integration of ISRU consumable production center dot Oxygen only from Mars atmosphere carbon dioxide center dot Oxygen, fuel, water, from extraterrestrial soil/regolith Test bed to evaluate long duration life, operations, maintenance on hardware, sensors, and autonomy

A rotating arm using shape-memory alloy

NASA Technical Reports Server (NTRS)

Jenkins, Phillip P.; Landis, Geoffrey A.

1995-01-01

NASA's Mars Pathfinder mission, to be launched in 1996, reflects a new philosophy of exploiting new technologies to reduce mission cost and accelerate the pace of space exploration. One of the experiments on board Pathfinder will demonstrate the first use in space of a multi-cycle, electrically-activated, shape-memory alloy (SMA) actuator. SMA's are metal alloys which, when heated, undergo a crystalline phase change. This change in phase alters the alloy lattice-constant, resulting in a change of dimension. Upon cooling, the alloy returns to its original lattice formation. Wire drawn from an SMA contracts in length when heated. The reversible change in length is 3 percent to 5 percent. The wire used in this actuator is a nickel-titanium alloy known as nitinol.

Sojourner APXS at Moe - Left Eye

NASA Image and Video Library

1999-07-02

The Sojourner rover's Alpha Proton X-ray Spectrometer (APXS) is shown deployed against the rock "Moe" on the afternoon of Sol 64 (September 7). The rocks to the left of Moe are "Shark" (left of Sojourner) and "Half Dome" (behind Sojourner). They were previously measured by the APXS. The image was taken by the Imager for Mars Pathfinder (IMP). Sojourner spent 83 days of a planned seven-day mission exploring the Martian terrain, acquiring images, and taking chemical, atmospheric and other measurements. The final data transmission received from Pathfinder was at 10:23 UTC on September 27, 1997. Although mission managers tried to restore full communications during the following five months, the successful mission was terminated on March 10, 1998. http://photojournal.jpl.nasa.gov/catalog/PIA01560

Electrodynamic Dust Shield for Solar Panels on Mars

NASA Technical Reports Server (NTRS)

Calle, C. I.; Buhler, C. R.; Mantovani, J. G.; Clements S.; Chen, A.; Mazumder, M. K.; Biris, A. S.; Nowicki, A. W.

2004-01-01

The Materials Adherence Experiment on the Mars Pathfinder mission measured an obscuration of the solar arrays due to dust deposition at a rate of about 0.2 8% per day. It was estimated that settling dust may cause degradation in performance of a solar panel of between 22% and 89% over the course of two years [1, 2]. These results were obtained without the presence of a global dust storm. Several types of adherence forces keep dust particles attached to surfaces. The most widely discussed adherence force is the electrostatic force. Laboratory experiments [3] as well as indirect evidence from the Wheel Abrasion Experiment on Pathfinder [4] indicate that it is very likely that the particles suspended in the Martian atmosphere are electrostatically charged.

Drill/borescope System for the Mars Polar Pathfinder

NASA Technical Reports Server (NTRS)

Paige, D. A.; Wood, S. E.; Vasavada, A. R.

1993-01-01

The primary goals of the Mars Polar Pathfinder (MPP) Discovery Mission are to characterize the composition and structure of Mars' north polar ice cap, and to determine whether a climate record may be preserved in layers of ice and dust. The MPP would land as close as possible to the geographic north pole of Mars and use a set of instruments similar to those used by glaciologists to study polar ice caps on Earth: a radar sounder, a drill/borescope system, and a thermal probe. The drill/borescope system will drill approximately 50 cm into the surface and image the sides of the hole at 10 micron resolution for compositional and stratigraphic analysis. Several uncertainties have guided the development of this instrument, and they are discussed.

Mars Pathfinder Near-Field Rock Distribution Re-Evaluation

NASA Technical Reports Server (NTRS)

Haldemann, A. F. C.; Golombek, M. P.

2003-01-01

We have completed analysis of a new near-field rock count at the Mars Pathfinder landing site and determined that the previously published rock count suggesting 16% cumulative fractional area (CFA) covered by rocks is incorrect. The earlier value is not so much wrong (our new CFA is 20%), as right for the wrong reason: both the old and the new CFA's are consistent with remote sensing data, however the earlier determination incorrectly calculated rock coverage using apparent width rather than average diameter. Here we present details of the new rock database and the new statistics, as well as the importance of using rock average diameter for rock population statistics. The changes to the near-field data do not affect the far-field rock statistics.

Tough Textiles Protect Payloads and Public Safety Officers

NASA Technical Reports Server (NTRS)

2009-01-01

In order to create the Mars Pathfinder s mission-critical airbags in the 1990s, NASA s Jet Propulsion Laboratory collaborated with New Ipswich, New Hampshire s Warwick Mills Inc. to weave multi-layer textiles for the airbags for both Pathfinder and the Mars Exploration Rovers. Warwick Mills applied techniques from the collaboration to its puncture- and impact-resistant TurtleSkin product line. The company's metal flex armor (MFA) vests offer stab protection comparable with rigid steel plates and over 50,000 of the vests have sold. The SoftPlate body armor offers protection from handgun bullets, and like the MFA, is designed to be more comfortable than rigid vests. International public safety and military customers are now benefiting from the TurtleSkin products.

Pathfinder operations

NASA Technical Reports Server (NTRS)

Wilcher, J.; Stelzried, C.; Finley, S.

1986-01-01

In 1981, the Inter-Agency Consultative Group (composed of European, Soviet, Japanese and American space agency representatives) conceived the idea of using the two Soviet Vega spacecraft as pathfinders for Giotto since they would arrive at Halley's Comet approximately one week before Giotto. The Vega trajectory data and the Halley camera angle data were combined to improve the comet orbit accuracy. This was used to improve the Giotto fly-by targeting. The DSN performed delta DOR (VLBI) and one-way Doppler measurements of the Vega spacecraft for orbit determination. Although the early part-up phase had many problems, the results during the critical November 30, 1985 to March 4, 1986 operational phase had an overall 95 percent success rate, with 59 successes out of 62 two-station passes.

Near-Net Forging Technology Demonstration Program

NASA Technical Reports Server (NTRS)

Hall, I. Keith

1996-01-01

Significant advantages in specific mechanical properties, when compared to conventional aluminum (Al) alloys, make aluminum-lithium (Al-Li) alloys attractive candidate materials for use in cryogenic propellant tanks and dry bay structures. However, the cost of Al-Li alloys is typically five times that of 2219 aluminum. If conventional fabrication processes are employed to fabricate launch vehicle structure, the material costs will restrict their utilization. In order to fully exploit the potential cost and performance benefits of Al-Li alloys, it is necessary that near-net manufacturing methods be developed to off-set or reduce raw material costs. Near-net forging is an advanced manufacturing method that uses elevated temperature metal movement (forging) to fabricate a single piece, near-net shape, structure. This process is termed 'near-net' because only a minimal amount of post-forge machining is required. The near-net forging process was developed to reduce the material scrap rate (buy-to-fly ratio) and fabrication costs associated with conventional manufacturing methods. The goal for the near-net forging process, when mature, is to achieve an overall cost reduction of approximately 50 percent compared with conventional manufacturing options for producing structures fabricated from Al-Li alloys. This NASA Marshall Space Flight Center (MSFC) sponsored program has been a part of a unique government / industry partnership, coordinated to develop and demonstrate near-net forging technology. The objective of this program was to demonstrate scale-up of the near-net forging process. This objective was successfully achieved by fabricating four integrally stiffened, 170- inch diameter by 20-inch tall, Al-Li alloy 2195, Y-ring adapters. Initially, two 2195 Al-Li ingots were converted and back extruded to produce four cylindrical blockers. Conventional ring rolling of the blockers was performed to produce ring preforms, which were then contour ring rolled to produce 'contour preforms'. All of the contour preforms on this first-of-a-kind effort were imperfect, and the ingot used to fabricate two of the preforms was of an earlier vintage. As lessons were learned throughout the program, the tooling and procedures evolved, and hence the preform quality. Two of the best contour preforms were near- net forged to produce a process pathfinder Y-ring adapter and a 'mechanical properties pathfinder' Y-ring adapter. At this point, Lockheed Martin Astronautics elected to procure additional 2195 aluminum-lithium ingot of the latest vintage, produce two additional preforms, and substitute them for older vintage material non-perfectly filled preforms already produced on this contract. The existing preforms could have been used to fulfill the requirements of the contract.

An Overview of Future NASA Missions, Concepts, and Technologies Related to Imaging of the World's Land Areas

NASA Technical Reports Server (NTRS)

Salomonson, Vincent V.

1999-01-01

In the near term NASA is entering into the peak activity period of the Earth Observing System (EOS). The EOS AM-1 /"Terra" spacecraft is nearing launch and operation to be followed soon by the New Millennium Program (NMP) Earth Observing (EO-1) mission. Other missions related to land imaging and studies include EOS PM-1 mission, the Earth System Sciences Program (ESSP) Vegetation Canopy Lidar (VCL) mission, the EOS/IceSat mission. These missions involve clear advances in technologies and observational capability including improvements in multispectral imaging and other observing strategies, for example, "formation flying". Plans are underway to define the next era of EOS missions, commonly called "EOS Follow-on" or EOS II. The programmatic planning includes concepts that represent advances over the present Landsat-7 mission that concomitantly recognize the advances being made in land imaging within the private sector. The National Polar Orbiting Environmental Satellite Series (NPOESS) Preparatory Project (NPP) is an effort that will help to transition EOS medium resolution (herein meaning spatial resolutions near 500 meters), multispectral measurement capabilities such as represented by the EOS Moderate Resolution Imaging Spectroradiometer (MODIS) into the NPOESS operational series of satellites. Developments in Synthetic Aperture Radar (SAR) and passive microwave land observing capabilities are also proceeding. Beyond these efforts the Earth Science Enterprise Technology Strategy is embarking efforts to advance technologies in several basic areas: instruments, flight systems and operational capability, and information systems. In the case of instruments architectures will be examined that offer significant reductions in mass, volume, power and observational flexibility. For flight systems and operational capability, formation flying including calibration and data fusion, systems operation autonomy, and mechanical and electronic innovations that can reduce spacecraft and subsystem resource requirements. The efforts in information systems will include better approaches for linking multiple data sets, extracting and visualizing information, and improvements in collecting, compressing, transmitting, processing, distributing and archiving data from multiple platforms. Overall concepts such as sensor webs, constellations of observing systems, and rapid and tailored data availability and delivery to multiple users comprise and notions Earth Science Vision for the future.

KSC-2009-1624

NASA Image and Video Library

2009-02-04

VANDENBERG AIR FORCE BASE, Calif. -- Inside the Astrotech payload processing facility at Vandenberg Air Force Base in California, Orbital Sciences technicians conduct an ultraviolet light cleanliness inspection on the payload load isolators of the Taurus XL launch vehicle for the Orbiting Carbon Observatory, or OCO, before installation on the ballast ring. From left are Dana Frederic, Bill Nelson and Randy Bone. The OCO is an Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory will collect precise global measurements of carbon dioxide in the Earth's atmosphere. Scientists will analyze the data returned to better understand the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Launch is targeted for Feb. 24 from Space Launch Complex 576-E at Vandenberg. Photo credit: NASA/Richard Nielsen, KSC

Health Physics Innovations Developed During Cassini for Future Space Applications

NASA Technical Reports Server (NTRS)

Nickell, Rodney E.; Rutherford, Theresa M.; Marmaro, George M.

1999-01-01

The long history of space flight includes missions that used Space Nuclear Auxiliary Power devices, starting with the Transit 4A Spacecraft (1961), continuing through the Apollo, Pioneer, Viking, Voyager, Galileo, Ulysses, Mars Pathfinder, and most recently, Cassini (1997). All Major Radiological Source (MRS) missions were processed at Kennedy Space Center/Cape Canaveral Air Station (KSC/CCAS) Launch Site in full compliance with program and regulatory requirements. The cumulative experience gained supporting these past missions has led to significant innovations which will be useful for benchmarking future MRS mission ground processing. Innovations developed during ground support for the Cassini mission include official declaration of sealed-source classifications, utilization of a mobile analytical laboratory, employment of a computerized dosimetry record management system, and cross-utilization of personnel from related disciplines.

Drag-Free Performance of the ST7 Disturbance Reduction System Flight Experiment on the LISA Pathfinder

NASA Technical Reports Server (NTRS)

Maghami, Peiman G.; O'Donnell, James R.; Hsu, Oscar H.; Ziemer, John K.; Dunn, Charles E.

2017-01-01

The Space Technology-7 Disturbance Reduction System (DRS) is an experiment package aboard the European Space Agency (ESA) LISA Pathfinder spacecraft. LISA Pathfinder launched from Kourou, French Guiana on December 3, 2015. The DRS is tasked to validate two specific technologies: colloidal micro-Newton thrusters (CMNT) to provide low-noise control capability of the spacecraft, and drag-free controlflight. This validation is performed using highly sensitive drag-free sensors, which are provided by the LISA Technology Package of the European Space Agency. The Disturbance Reduction System is required to maintain the spacecrafts position with respect to a free-floating test mass to better than 10nm/(square root of Hz), along its sensitive axis (axis in optical metrology). It also has a goal of limiting the residual accelerations of any of the two test masses to below 30 x 10(exp -14) (1 + ([f/3 mHz](exp 2))) m/sq s/(square root of Hz), over the frequency range of 1 to 30 mHz.This paper briefly describes the design and the expected on-orbit performance of the control system for the two modes wherein the drag-free performance requirements are verified. The on-orbit performance of these modes are then compared to the requirements, as well as to the expected performance, and discussed.