Science.gov

Sample records for 20-meter solar sail

  1. 20 Meter Solar Sail Analysis and Correlation

    NASA Technical Reports Server (NTRS)

    Taleghani, B. K.; Lively, P. S.; Banik, J.; Murphy, D. M.; Trautt, T. A.

    2005-01-01

    This paper describes finite element analyses and correlation studies to predict deformations and vibration modes/frequencies of a 20-meter solar sail system developed by ATK Space Systems. Under the programmatic leadership of NASA Marshall Space Flight Center's In-Space Propulsion activity, the 20-meter solar sail program objectives were to verify the design, to assess structural responses of the sail system, to implement lessons learned from a previous 10-meter quadrant system analysis and test program, and to mature solar sail technology to a technology readiness level (TRL) of 5. For this 20 meter sail system, static and ground vibration tests were conducted in NASA Glenn Research Center's 100 meter diameter vacuum chamber at Plum Brook station. Prior to testing, a preliminary analysis was performed to evaluate test conditions and to determine sensor and actuator locations. After testing was completed, an analysis of each test configuration was performed. Post-test model refinements included updated properties to account for the mass of sensors, wiring, and other components used for testing. This paper describes the development of finite element models (FEM) for sail membranes and masts in each of four quadrants at both the component and system levels, as well as an optimization procedure for the static test/analyses correlation.

  2. 20 Meter Solar Sail Analysis and Correlation

    NASA Technical Reports Server (NTRS)

    Taleghani, B.; Lively, P.; Banik, J.; Murphy, D.; Trautt, T.

    2005-01-01

    This presentation discusses studies conducted to determine the element type and size that best represents a 20-meter solar sail under ground-test load conditions, the performance of test/Analysis correlation by using Static Shape Optimization Method for Q4 sail, and system dynamic. TRIA3 elements better represent wrinkle patterns than do QUAD3 elements Baseline, ten-inch elements are small enough to accurately represent sail shape, and baseline TRIA3 mesh requires a reasonable computation time of 8 min. 21 sec. In the test/analysis correlation by using Static shape optimization method for Q4 sail, ten parameters were chosen and varied during optimization. 300 sail models were created with random parameters. A response surfaces for each targets which were created based on the varied parameters. Parameters were optimized based on response surface. Deflection shape comparison for 0 and 22.5 degrees yielded a 4.3% and 2.1% error respectively. For the system dynamic study testing was done on the booms without the sails attached. The nominal boom properties produced a good correlation to test data the frequencies were within 10%. Boom dominated analysis frequencies and modes compared well with the test results.

  3. TESTING OF A 20-METER SOLAR SAIL SYSTEM

    NASA Technical Reports Server (NTRS)

    Gaspar, J. L.; Behun, V.; Mann, T.; Murphy D.; Macy, B.

    2005-01-01

    This paper describes the structural dynamic tests conducted in-vacuum on the Scalable Square Solar Sail (S(sup 4)) System 20-meter test article developed by ATK Space Systems as part of a ground demonstrator system development program funded by NASA's In-Space Propulsion program1-3. These tests were conducted for the purpose of validating analytical models that would be required by a flight test program to predict in space performance4. Specific tests included modal vibration tests on the solar sail system in a 1 Torr vacuum environment using various excitation locations and techniques including magnetic excitation at the sail quadrant corners, piezoelectric stack actuation at the mast roots, spreader bar excitation at the mast tips, and bi-morph piezoelectric patch actuation on the sail cords. The excitation methods were evaluated for their suitability to in-vacuum ground testing and their traceability to the development of on-orbit flight test techniques. The solar sail masts were also tested in ambient atmospheric conditions and these results are also discussed.

  4. TESTING OF A 20-METER SOLAR SAIL SYSTEM

    NASA Technical Reports Server (NTRS)

    Gaspar, Jim L.; Behun, Vaughan; Mann, Troy; Murphy, Dave; Macy, Brian

    2005-01-01

    This paper describes the structural dynamic tests conducted in-vacuum on the Scalable Square Solar Sail (S(sup 4)) System 20-meter test article developed by ATK Space Systems as part of a ground demonstrator system development program funded by NASA's In-Space Propulsion program. These tests were conducted for the purpose of validating analytical models that would be required by a flight test program to predict in space performance. Specific tests included modal vibration tests on the solar sail system in a 1 Torr vacuum environment using various excitation locations and techniques including magnetic excitation at the sail quadrant corners, piezoelectric stack actuation at the mast roots, spreader bar excitation at the mast tips, and bi-morph piezoelectric patch actuation on the sail cords. The excitation methods are evaluated for their suitability to in-vacuum ground testing and their traceability to the development of on-orbit flight test techniques. The solar sail masts were also tested in ambient atmospheric conditions and these results are also discussed.

  5. Ground Testing A 20-Meter Inflation Deployed Solar Sail

    NASA Technical Reports Server (NTRS)

    Mann, Troy; Behun, Vaughn; Lichodziejewski, David; Derbes, Billy; Sleight, David

    2006-01-01

    Solar sails have been proposed for a variety of future space exploration missions and provide a cost effective source of propellantless propulsion. Solar sails span very large areas to capture and reflect photons from the Sun and are propelled through space by the transfer of momentum from the photons to the solar sail. The thrust of a solar sail, though small, is continuous and acts for the life of the mission without the need for propellant. Recent advances in materials and ultra-low mass gossamer structures have enabled a host of useful space exploration missions utilizing solar sail propulsion. The team of L Garde, NASA Jet Propulsion Laboratory (JPL), Ball Aerospace, and NASA Langley Research Center, under the direction of the NASA In-Space Propulsion Office (ISP), has been developing a scalable solar sail configuration to address NASA s future space propulsion needs. The 100-m baseline solar sail concept was optimized around the one astronomical unit (AU) Geostorm mission, and features a Mylar sail membrane with a striped-net sail suspension architecture with inflation-deployed sail support beams consisting of inflatable sub-Tg (glass transition temperature) rigidizable semi-monocoque booms and a spreader system. The solar sail has vanes integrated onto the tips of the support beams to provide full 3-axis control of the solar sail. This same structural concept can be scaled to meet the requirements of a number of other NASA missions. Static and dynamic testing of a 20m scaled version of this solar sail concept have been completed in the Space Power Facility (SPF) at the NASA Glenn Plum Brook facility under vacuum and thermal conditions simulating the operation of a solar sail in space. This paper details the lessons learned from these and other similar ground based tests of gossamer structures during the three year solar sail project.

  6. Fabrication and Deployment Testing of Solar Sail Quadrants for a 20-Meter Solar Sail Ground Test System Demonstration

    NASA Technical Reports Server (NTRS)

    Laue, Greg; Case, David; Moore, Jim

    2005-01-01

    A 20-meter Scalable Square Solar Sail (S(sup 4)) System was produced and successfully completed functional vacuum testing in NASA Glenn's Space Power Facility at Plum Brook Station Ohio in May 2005. The S(sup 4) system was designed and developed by ATK Space Systems, and the design and production of the Solar Sails for this system was carried out by SRS Technologies. The S(sup 4) system consists of a central structure with four deployable carbon fiber masts that support four triangular sails. SRS has developed an effective and efficient design for triangular sail quadrants that are supported at three points and provide a flat reflective surface with a high fill factor. This sail design is robust enough for deployments in a one atmosphere, one gravity environment and incorporates several advanced features including adhesiveless seaming of membrane strips, compliant edge borders to allow for film membrane cord strain mismatch without causing wrinkling and low mass (3% of total sail mass) ripstop. This paper will outline some of the sail design and fabrication processes and the mature production, packaging and deployment processes that have been developed. This paper will also detail the successful ambient and vacuum testing of the sails and the ATK spacecraft structure. Based on recent experience and testing, SRS is confidant that high Technology Readiness Level (TRL) 5-6 solar sails in the 40-120-meter size range with areal density in the 4-5 grams per square meters (sail minus structure) range can be produced with existing technology. Additional film production research will lead to further reductions in film thickness to less than 1 micron enabling production of sails with areal densities as low as 2.0 grams per square meters using the current design, resulting in a system areal densities as low as 5.3 grams per square meters (sail and structure). These areal densities are low enough to allow nearly all of the Solar Sail missions that have been proposed by the

  7. TRL Assessment of Solar Sail Technology Development Following the 20-Meter System Ground Demonstrator Hardware Testing

    NASA Technical Reports Server (NTRS)

    Young, Roy M.; Adams, Charles L.

    2010-01-01

    The NASA In-Space Propulsion Technology (ISPT) Projects Office sponsored two separate, independent solar sail system design and development demonstration activities during 2002-2005. ATK Space Systems of Goleta, CA was the prime contractor for one development team and L' Garde, Inc. of Tustin, CA was the prime contractor for the other development team. The goal of these activities was to advance the technology readiness level (TRL) of solar sail propulsion from 3 towards 6 by the year 2006. Component and subsystem fabrication and testing were completed successfully, including the ground deployment of 10-meter and 20-meter demonstration hardware systems under vacuum conditions. The deployment and structural testing of the 20-meter solar sail systems was conducted in the 30 meter diameter Space Power Facility thermal-vacuum chamber at NASA Glenn Plum Brook in April though August, 2005. This paper will present the results of the TRL assessment following the solar sail technology development activities associated with the design, development, analysis and testing of the 20-meter system ground demonstrators.

  8. TRL Assessment of Solar Sail Technology Development Following the 20-Meter System Ground Demonstrator Hardware Testing

    NASA Technical Reports Server (NTRS)

    Young, Roy M.; Montgomery, Edward E.; Montgomery, Sandy; Adams, Charles L.

    2007-01-01

    The NASA In-Space Propulsion Technology (ISPT) Projects Office has been sponsoring 2 separate, independent system design and development hardware demonstration activities during 2002-2005. ATK Space Systems of Goleta, CA was the prime contractor for one development team and L'Garde, Inc. of Tustin, CA was the prime contractor for the other development team. The goal of these activities was to advance the technology readiness level (TRL) of solar sail propulsion from 3 towards 6 by the year 2006. Component and subsystem fabrication and testing were completed successfully, including the ground deployment of 10-meter and 20-meter ground demonstration hardware systems under vacuum conditions. The deployment and structural testing of the 20-meter solar sail systems was conducted in the 30 meter diameter Space Power Facility thermal-vacuum chamber at NASA Glenn Plum Brook in April though August, 2005. This paper will present the results of the TRL assessment following the solar sail technology development activities associated with the design, development, analysis and testing of the 20-meter system ground demonstrators. Descriptions of the system designs for both the ATK and L'Garde systems will be presented. Changes, additions and evolution of the system designs will be highlighted. A description of the modeling and analyses activities performed by both teams, as well as testing conducted to raise the TRL of solar sail technology will be presented. A summary of the results of model correlation activities will be presented. Finally, technology gaps identified during the assessment and gap closure plans will be presented, along with "lessons learned", subsequent planning activities and validation flight opportunities for solar sail propulsion technology.

  9. Structural Analysis and Test Comparison of a 20-Meter Inflation-Deployed Solar Sail

    NASA Technical Reports Server (NTRS)

    Sleight, David W.; Mann, Troy; Lichodziejewski, David; Derbes, Billy

    2006-01-01

    Under the direction of the NASA In-Space Propulsion Technology Office, the team of L Garde, NASA Jet Propulsion Laboratory, Ball Aerospace, and NASA Langley Research Center has been developing a scalable solar sail configuration to address NASA s future space propulsion needs. Prior to a flight experiment of a full-scale solar sail, a comprehensive test program was implemented to advance the technology readiness level of the solar sail design. These tests consisted of solar sail component, subsystem, and sub-scale system ground tests that simulated the aspects of the space environment such as vacuum and thermal conditions. In July 2005, a 20-m four-quadrant solar sail system test article was tested in the NASA Glenn Research Center s Space Power Facility to measure its static and dynamic structural responses. Key to the maturation of solar sail technology is the development of validated finite element analysis (FEA) models that can be used for design and analysis of solar sails. A major objective of the program was to utilize the test data to validate the FEA models simulating the solar sail ground tests. The FEA software, ABAQUS, was used to perform the structural analyses to simulate the ground tests performed on the 20-m solar sail test article. This paper presents the details of the FEA modeling, the structural analyses simulating the ground tests, and a comparison of the pretest and post-test analysis predictions with the ground test results for the 20-m solar sail system test article. The structural responses that are compared in the paper include load-deflection curves and natural frequencies for the beam structural assembly and static shape, natural frequencies, and mode shapes for the solar sail membrane. The analysis predictions were in reasonable agreement with the test data. Factors that precluded better correlation of the analyses and the tests were unmeasured initial conditions in the test set-up.

  10. Solar Sails

    NASA Technical Reports Server (NTRS)

    Young, Roy

    2006-01-01

    The Solar Sail Propulsion investment area has been one of the three highest priorities within the In-Space Propulsion Technology (ISPT) Project. In the fall of 2003, the NASA Headquarters' Science Mission Directorate provided funding and direction to mature the technology as far as possible through ground research and development from TRL 3 to 6 in three years. A group of experts from government, industry, and academia convened in Huntsville, Alabama to define technology gaps between what was needed for science missions to the inner solar system and the current state of the art in ultra1ightweight materials and gossamer structure design. This activity set the roadmap for development. The centerpiece of the development would be the ground demonstration of scalable solar sail systems including masts, sails, deployment mechanisms, and attitude control hardware and software. In addition, new materials would be subjected to anticipated space environments to quantify effects and assure mission life. Also, because solar sails are huge structures, and it is not feasible to validate the technology by ground test at full scale, a multi-discipline effort was established to develop highly reliable analytical models to serve as mission assurance evidence in future flight program decision-making. Two separate contractor teams were chosen to develop the SSP System Ground Demonstrator (SGD). After a three month conceptual mission/system design phase, the teams developed a ten meter diameter pathfinder set of hardware and subjected it to thermal vacuum tests to compare analytically predicted structural behavior with measured characteristics. This process developed manufacturing and handling techniques and refined the basic design. In 2005, both contractor teams delivered 20 meter, four quadrant sail systems to the largest thermal vacuum chamber in the world in Plum Brook, Ohio, and repeated the tests. Also demonstrated was the deployment and articulation of attitude control

  11. Solar Sailing

    NASA Technical Reports Server (NTRS)

    Johnson, Les

    2009-01-01

    Solar sailing is a topic of growing technical and popular interest. Solar sail propulsion will make space exploration more affordable and offer access to destinations within (and beyond) the solar system that are currently beyond our technical reach. The lecture will describe solar sails, how they work, and what they will be used for in the exploration of space. It will include a discussion of current plans for solar sails and how advanced technology, such as nanotechnology, might enhance their performance. Much has been accomplished recently to make solar sail technology very close to becoming an engineering reality and it will soon be used by the world s space agencies in the exploration of the solar system and beyond. The first part of the lecture will summarize state-of-the-art space propulsion systems and technologies. Though these other technologies are the key to any deep space exploration by humans, robots, or both, solar-sail propulsion will make space exploration more affordable and offer access to distant and difficult destinations. The second part of the lecture will describe the fundamentals of space solar sail propulsion and will describe the near-, mid- and far-term missions that might use solar sails as a propulsion system. The third part of the lecture will describe solar sail technology and the construction of current and future sailcraft, including the work of both government and private space organizations.

  12. Solar Sail Spaceflight Simulation

    NASA Technical Reports Server (NTRS)

    Lisano, Michael; Evans, James; Ellis, Jordan; Schimmels, John; Roberts, Timothy; Rios-Reyes, Leonel; Scheeres, Daniel; Bladt, Jeff; Lawrence, Dale; Piggott, Scott

    2007-01-01

    The Solar Sail Spaceflight Simulation Software (S5) toolkit provides solar-sail designers with an integrated environment for designing optimal solar-sail trajectories, and then studying the attitude dynamics/control, navigation, and trajectory control/correction of sails during realistic mission simulations. Unique features include a high-fidelity solar radiation pressure model suitable for arbitrarily-shaped solar sails, a solar-sail trajectory optimizer, capability to develop solar-sail navigation filter simulations, solar-sail attitude control models, and solar-sail high-fidelity force models.

  13. SMART Solar Sail

    NASA Technical Reports Server (NTRS)

    Curtis, Steven A.

    2005-01-01

    A report summarizes the design concept of a super miniaturized autonomous reconfigurable technology (SMART) solar sail a proposed deployable, fully autonomous solar sail for use in very fine station keeping of a spacecraft. The SMART solar sail would include a reflective film stretched among nodes of a SMART space frame made partly of nanotubule struts. A microelectromechanical system (MEMS) at each vertex of the frame would spool and unspool nanotubule struts between itself and neighboring nodes to vary the shape of the frame. The MEMSs would be linked, either wirelessly or by thin wires within the struts, to an evolvable neural software system (ENSS) that would control the MEMSs to reconfigure the sail as needed. The solar sail would be highly deformable from an initially highly compressed configuration, yet also capable of enabling very fine maneuvering of the spacecraft by means of small sail-surface deformations. The SMART Solar Sail would be connected to the main body of the spacecraft by a SMART multi-tether structure, which would include MEMS actuators like those of the frame plus tethers in the form of longer versions of the struts in the frame.

  14. Solar Sail Propulsion Technology Readiness Level Database

    NASA Technical Reports Server (NTRS)

    Adams, Charles L.

    2004-01-01

    The NASA In-Space Propulsion Technology (ISPT) Projects Office has been sponsoring 2 solar sail system design and development hardware demonstration activities over the past 20 months. Able Engineering Company (AEC) of Goleta, CA is leading one team and L Garde, Inc. of Tustin, CA is leading the other team. Component, subsystem and system fabrication and testing has been completed successfully. The goal of these activities is to advance the technology readiness level (TRL) of solar sail propulsion from 3 towards 6 by 2006. These activities will culminate in the deployment and testing of 20-meter solar sail system ground demonstration hardware in the 30 meter diameter thermal-vacuum chamber at NASA Glenn Plum Brook in 2005. This paper will describe the features of a computer database system that documents the results of the solar sail development activities to-date. Illustrations of the hardware components and systems, test results, analytical models, relevant space environment definition and current TRL assessment, as stored and manipulated within the database are presented. This database could serve as a central repository for all data related to the advancement of solar sail technology sponsored by the ISPT, providing an up-to-date assessment of the TRL of this technology. Current plans are to eventually make the database available to the Solar Sail community through the Space Transportation Information Network (STIN).

  15. Recent Advances in Solar Sail Propulsion at NASA

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Young, Roy M.; Montgomery, Edward E., IV

    2006-01-01

    Supporting NASA's Science Mission Directorate, the In-Space Propulsion Technology Program is developing solar sail propulsion for use in robotic science and exploration of the solar system. Solar sail propulsion will provide longer on-station operation, increased scientific payload mass fraction, and access to previously inaccessible orbits for multiple potential science missions. Two different 20-meter solar sail systems were produced and successfully completed functional vacuum testing last year in NASA Glenn's Space Power Facility at Plum Brook Station, Ohio. The sails were designed and developed by ATK Space Systems and L'Garde, respectively. These sail systems consist of a central structure with four deployable booms that support the sails. This sail designs are robust enough for deployments in a one atmosphere, one gravity environment, and are scalable to much larger solar sails-perhaps as much as 150 meters on a side. In addition, computation modeling and analytical simulations have been performed to assess the scalability of the technology to the large sizes (>150 meters) required for first generation solar sails missions. Life and space environmental effects testing of sail and component materials are also nearly complete. This paper will summarize recent technology advancements in solar sails and their successful ambient and vacuum testing.

  16. Recent Advances in Solar Sail Propulsion Systems at NASA

    NASA Technical Reports Server (NTRS)

    Johnson, Les

    2006-01-01

    Supporting NASA's Science Mission Directorate, the In-Space Propulsion Technology Program is developing solar sail propulsion for use in robotic science and exploration of the solar system. Solar sail propulsion has the potential to provide longer on-station operation, increased scientific payload mass fraction, and access to previously inaccessible orbits for multiple potential science missions. Two different 20-meter solar sail systems were produced and successfully completed functional vacuum testing last year in NASA Glenn s Space Power Facility at Plum Brook Station Ohio. The sails were designed and developed by ATK Space Systems and L'Garde, respectively. The sail systems consist of a central structure with four deployable booms that support the sails. The sail designs are robust enough for deployments in a one atmosphere, one gravity environment and are scalable to much larger solar sails - perhaps as large as 150 meters on a side. In addition, computational modeling and analytical simulations have been performed to assess the scalability of the technology to the large sizes (150 meters) required to implement the first generation of missions using solar sails. Life and space environmental effects testing of sail and component materials are also nearly complete. This paper will summarize recent technology advancements in solar sails and their successful ambient and vacuum environment testing.

  17. The Physics and Technology of Solar Sail Spacecraft.

    ERIC Educational Resources Information Center

    Dwivedi, B. N.; McInnes, C. R.

    1991-01-01

    Various aspects of the solar sail spacecraft such as solar sailing, solar sail design, navigation with solar sails, solar sail mission applications and future prospects for solar sailing are described. Several possible student projects are suggested. (KR)

  18. Solar Sail Interstellar Travel - 1. Thickness of Solar Sail Films

    NASA Astrophysics Data System (ADS)

    Ya Kezerashvili, R.

    An exploration of the outer solar system using solar sail propulsion with high cruise speed requires an acceleration of the sail craft in the near-Sun space region. When spacecraft approaches the Sun there are at least two important factors that have an effect on the thickness of solar sail film and therefore on the reflection ability of the sail: the temperature dependence of electrical conductivity of sail material and existence of a wide range of solar electromagnetic radiation frequencies. Applying the system of Maxwell's equations for linear conducting media the minimum film thickness that provides the maximum reflectance is found and dependence of this minimum thickness on temperature as well as on electromagnetic spectrum of solar radiation is investigated. It is shown that temperature dependence of the conductivity of the film under a constant temperature coefficient of conductivity requires an increase of the thickness of the solar sail by a factor 2 to 3. Consideration of the temperature coefficient of conductivity dependence on temperature also requires an increase of film thickness by more than 35% at high temperatures. When the frequency dependence of the conductivity is taken into account the minimal thickness of the solar sail film increases significantly (almost by a factor of 4), but at the same time exhibits the negligible dependence on the wavelength. We suggest that these factors should be taken into consideration in the solar sail design.

  19. Status of Solar Sail Propulsion: Moving Toward an Interstellar Probe

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Young, Roy M.; Montgomery, Edward E., IV

    2006-01-01

    NASA's In-Space Propulsion Technology Program has developed the first-generation of solar sail propulsion systems sufficient to accomplish inner solar system science and exploration missions. These first-generation solar sails, when operational, will range in size from 40 meters to well over 100 meters in diameter and have an areal density of less than 13 grams-per-square meter. A rigorous, multiyear technology development effort culminated last year in the testing of two different 20-meter solar sail systems under thermal vacuum conditions. This effort provided a number of significant insights into the optimal design and expected performance of solar sails as well as an understanding of the methods and costs of building and using them. In a separate effort, solar sail orbital analysis tools for mission design were developed and tested. Laboratory simulations of the effects of long-term space radiation exposure were also conducted on two candidate solar sail materials. Detailed radiation and charging environments were defined for mission trajectories outside the protection of the earth's magnetosphere, in the solar wind environment. These were used in other analytical tools to prove the adequacy of sail design features for accommodating the harsh space environment. Preceding, and in conjunction with these technology efforts, NASA sponsored several mission application studies for solar sails, including one that would use an evolved sail capability to support humanity's first mission into nearby interstellar space. The proposed mission is called the Interstellar Probe. The Interstellar Probe might be accomplished in several ways. A 200-meter sail, with an areal density approaching 1 gram-per-square meter, could accelerate a robotic probe to the very edge of the solar system in just under 20 years from launch. A sail using the technology just demonstrated could make the same mission, but take significantly longer. Conventional chemical propulsion systems would require

  20. Solar sail Engineering Development Mission

    NASA Technical Reports Server (NTRS)

    Price, H. W.

    1981-01-01

    Since photons have momentum, a useful force can be obtained by reflecting sunlight off of a large, low mass surface (most likely a very thin metal-coated plastic film) and robbing the light of some of its momentum. A solar sail Engineering Development Mission (EDM) is currently being planned by the World Space Foundation for the purpose of demonstrating and evaluating solar sailing technology and to gain experience in the design and operation of a spacecraft propelled by sunlight. The present plan is for the EDM spacecraft to be launched (sail stowed) in a spin-stabilized configuration into an initial elliptical orbit with an apogee of 36,000 km and a perigee of a few hundred kilometers. The spacecraft will then use its own chemical propulsion system to raise the perigee to at least 1,200 km. The deployed sail will have an area of 880 sq m and generate a solar force of about 0.007 N.

  1. The Physics of Solar Sails

    NASA Technical Reports Server (NTRS)

    Hollerman, William Andrew

    2003-01-01

    The concept of using photon pressure for propulsion has been considered since Tsiolkovsky in 1921. In fact, Tsiolkovsky and Tsander wrote of 'using tremendous mirrors of very thin sheets' and 'using the pressure of sunlight to attain cosmic velocities' in 1924. The term 'solar sailing' was coined in the late 1950s and was popularized by Arthur C. Clarke in the short story Sunjammer (The Wind From the Sun) in May 1964. The National Aeronautics and Space Administration (NASA) used sailing techniques to extend the operational life of the Mariner 10 spacecraft in 1974-1975. A problem in the control system was causing Mariner 10 to go off course. By controlling the attitude of Mariner 10 and the angle of the solar power panels relative to the Sun, ground controllers were able to correct the problem without using precious fuel. Once thought to be difficult or impossible, solar sailing has come out of science fiction and into the realm of possibility. Any spacecraft using this method would need to deploy a thin sail that could be as large as many kilometers in extent. Candidate sail materials should be: 1) strong, 2) ultra-lightweight (density of a few g/sq m), 3) able to be folded or crushed until deployed, 4) subject to minimal sagging or stretching, and 5) resistant to ionizing radiation, such as galactic and solar particles (electrons and protons), x-rays, ultraviolet light, and magnetically trapped charged particles. Solar sails must be resistant to each of these types of radiation.

  2. UltraSail CubeSat Solar Sail Flight Experiment

    NASA Technical Reports Server (NTRS)

    Carroll, David; Burton, Rodney; Coverstone, Victoria; Swenson, Gary

    2013-01-01

    UltraSail is a next-generation, highrisk, high-payoff sail system for the launch, deployment, stabilization, and control of very large (km2 class) solar sails enabling high payload mass fractions for interplanetary and deep space spacecraft. UltraSail is a non-traditional approach to propulsion technology achieved by combining propulsion and control systems developed for formation- flying microsatellites with an innovative solar sail architecture to achieve controllable sail areas approaching 1 km2, sail subsystem area densities approaching 1 g/m2, and thrust levels many times those of ion thrusters used for comparable deep space missions. UltraSail can achieve outer planetary rendezvous, a deep-space capability now reserved for high-mass nuclear and chemical systems. There is a twofold rationale behind the UltraSail concept for advanced solar sail systems. The first is that sail-andboom systems are inherently size-limited. The boom mass must be kept small, and column buckling limits the boom length to a few hundred meters. By eliminating the boom, UltraSail not only offers larger sail area, but also lower areal density, allowing larger payloads and shorter mission transit times. The second rationale for UltraSail is that sail films present deployment handling difficulties as the film thickness approaches one micrometer. The square sail requires that the film be folded in two directions for launch, and similarly unfolded for deployment. The film is stressed at the intersection of two folds, and this stress varies inversely with the film thickness. This stress can cause the film to yield, forming a permanent crease, or worse, to perforate. By rolling the film as UltraSail does, creases are prevented. Because the film is so thin, the roll thickness is small. Dynamic structural analysis of UltraSail coupled with dynamic control analysis shows that the system can be designed to eliminate longitudinal torsional waves created while controlling the pitch of the blades

  3. Status of solar sail technology within NASA

    NASA Astrophysics Data System (ADS)

    Johnson, Les; Young, Roy; Montgomery, Edward; Alhorn, Dean

    2011-12-01

    In the early 2000s, NASA made substantial progress in the development of solar sail propulsion systems for use in robotic science and exploration of the solar system. Two different 20-m solar sail systems were produced. NASA has successfully completed functional vacuum testing in their Glenn Research Center's Space Power Facility at Plum Brook Station, Ohio. The sails were designed and developed by Alliant Techsystems Space Systems and L'Garde, respectively. The sail systems consist of a central structure with four deployable booms that support each sail. These sail designs are robust enough for deployment in a one-atmosphere, one-gravity environment and are scalable to much larger solar sails - perhaps as large as 150 m on a side. Computation modeling and analytical simulations were performed in order to assess the scalability of the technology to the larger sizes that are required to implement the first generation of missions using solar sails. Furthermore, life and space environmental effects testing of sail and component materials was also conducted.NASA terminated funding for solar sails and other advanced space propulsion technologies shortly after these ground demonstrations were completed. In order to capitalize on the $30 M investment made in solar sail technology to that point, NASA Marshall Space Flight Center funded the NanoSail-D, a subscale solar sail system designed for possible small spacecraft applications. The NanoSail-D mission flew on board a Falcon-1 rocket, launched August 2, 2008. As a result of the failure of that rocket, the NanoSail-D was never successfully given the opportunity to achieve orbit. The NanoSail-D flight spare was flown in the Fall of 2010. This review paper summarizes NASA's investment in solar sail technology to date and discusses future opportunities.

  4. NanoSail-D: A Solar Sail Demonstration Mission

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Whorton, Mark; Heaton, Andy; Pinson, robin; Laue, Greg; Adams, Charles

    2009-01-01

    During the past decade, within the United States, NASA Marshall Space Flight Center (MSFC) was heavily engaged in the development of revolutionary new technologies for in-space propulsion. One of the major in-space propulsion technologies developed was a solar sail propulsion system. Solar sail propulsion uses the solar radiation pressure exerted by the momentum transfer of reflected photons to generate a net force on a spacecraft. To date, solar sail propulsion systems have been designed for large spacecraft in the tens to hundreds of kilograms mass range. Recently, however, MSFC has been investigating the application of solar sails for small satellite propulsion. Likewise, NASA Ames Research Center (ARC) has been developing small spacecraft missions that have a need for amass-efficient means of satisfying deorbit requirements. Hence, a synergistic collaboration was established between these two NASA field Centers with the objective of conducting a flight demonstration of solar sail technologies for small satellites. The NanoSail-D mission flew onboard the ill-fated Falcon Rocket launched August 2, 2008, and, due to the failure of that rocket, never achieved orbit. The NanoSail-D flight spare is ready for flight and a suitable launch arrangement is being actively pursued. Both the original sailcraft and the flight spare are hereafter referred to as NanoSail-D. The sailcraft consists of a sail subsystem stowed in a three-element CubeSat. Shortly after deployment of the NanoSail-D, the solar sail will deploy and mission operations will commence. This demonstration flight has two primary technical objectives: (1) to successfully stow and deploy the sail and (2) to demonstrate deorbit functionality. Given a near-term opportunity for launch on Falcon, the project was given the challenge of delivering the flight hardware in 6 mo, which required a significant constraint on flight system functionality. As a consequence, passive attitude stabilization of the spacecraft

  5. Solar Sail Propulsion for Interplanetary Cubesats

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Sobey, Alex; Sykes, Kevin

    2015-01-01

    NASA is developing two small satellite missions as part of the Advanced Exploration Systems (AES) Program, both of which will use a solar sail to enable their scientific objectives. Solar sails use sunlight to propel vehicles through space by reflecting solar photons from a large, mirror-like sail made of a lightweight, highly reflective material. This continuous photon pressure provides propellantless thrust, allowing for very high (Delta)V maneuvers on long-duration, deep space exploration. Since reflected light produces thrust, solar sails require no onboard propellant. Solar sail technology is rapidly maturing for space propulsion applications within NASA and around the world.

  6. UltraSail - Ultra-Lightweight Solar Sail Concept

    NASA Technical Reports Server (NTRS)

    Burton, Rodney L.; Coverstone, Victoria L.; Hargens-Rysanek, Jennifer; Ertmer, Kevin M.; Botter, Thierry; Benavides, Gabriel; Woo, Byoungsam; Carroll, David L.; Gierow, Paul A.; Farmer, Greg

    2005-01-01

    UltraSail is a next-generation high-risk, high-payoff sail system for the launch, deployment, stabilization and control of very large (sq km class) solar sails enabling high payload mass fractions for high (Delta)V. Ultrasail is an innovative, non-traditional approach to propulsion technology achieved by combining propulsion and control systems developed for formation-flying micro-satellites with an innovative solar sail architecture to achieve controllable sail areas approaching 1 sq km, sail subsystem area densities approaching 1 g/sq m, and thrust levels many times those of ion thrusters used for comparable deep space missions. Ultrasail can achieve outer planetary rendezvous, a deep space capability now reserved for high-mass nuclear and chemical systems. One of the primary innovations is the near-elimination of sail supporting structures by attaching each blade tip to a formation-flying micro-satellite which deploys the sail, and then articulates the sail to provide attitude control, including spin stabilization and precession of the spin axis. These tip micro-satellites are controlled by 3-axis micro-thruster propulsion and an on-board metrology system. It is shown that an optimum spin rate exists which maximizes payload mass.

  7. Solar sail on the track

    NASA Astrophysics Data System (ADS)

    Prado, Jean-Yves; Perret, Alain; Ozcariz, Ignazio

    Since the last IAF Congress in Malaga, where it has been stated by the IAF Education Committee that a Solar Sail Race to the Moon is worth to be recommended to IAF organization, the situation has evolved in a favorable way with respect to the U3P objectives to promote a race to the Moon with solar sails and be an entry. As the year 92 will be of great importance for Spain with the Summer Olympic Games in Barcelona, the International Exhibition of Sevilla and the celebration of the Castela sponsored Columbus odyssey, a unique opportunity for fund raising exists. A Spanish association, named Comision Vela Solar, has recently joined U3P to design and build a solar sail, ready for a launch in 1992, together with American and Japanese entries. This agreement between French and Spanish associations has given birth to an industrial cooperation between French firms, lead by MATRA-ESPACE and Spanish firms. In our paper, we describe the mission, give an update version of the rules of the race, draw the main features of the U3P-CVS sail and highlight the technological and educational benefits of this challenging project.

  8. Status of Solar Sail Technology Within NASA

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Young, Roy; Montgomery, Edward; Alhorn, Dean

    2010-01-01

    In the early 2000s, NASA made substantial progress in the development of solar sail propulsion systems for use in robotic science and exploration of the solar system. Two different 20-m solar sail systems were produced and they successfully completed functional vacuum testing in NASA Glenn Research Center's (GRC's) Space Power Facility at Plum Brook Station, Ohio. The sails were designed and developed by ATK Space Systems and L Garde, respectively. The sail systems consist of a central structure with four deployable booms that support the sails. These sail designs are robust enough for deployment in a one-atmosphere, one-gravity environment and were scalable to much larger solar sails perhaps as large as 150 m on a side. Computation modeling and analytical simulations were also performed to assess the scalability of the technology to the large sizes required to implement the first generation of missions using solar sails. Life and space environmental effects testing of sail and component materials were also conducted. NASA terminated funding for solar sails and other advanced space propulsion technologies shortly after these ground demonstrations were completed. In order to capitalize on the $30M investment made in solar sail technology to that point, NASA Marshall Space Flight Center (MSFC) funded the NanoSail-D, a subscale solar sail system designed for possible small spacecraft applications. The NanoSail-D mission flew on board the ill-fated Falcon-1 Rocket launched August 2, 2008, and due to the failure of that rocket, never achieved orbit. The NanoSail-D flight spare will be flown in the Fall of 2010. This paper will summarize NASA's investment in solar sail technology to-date and discuss future opportunities

  9. Solar Sail Readies for Early Warning Mission

    NASA Video Gallery

    NASA's Solar Sail project, directed by L’Garde of Tustin, Calif., plans to take this innovative technology beyond Earth's orbit. The spacecraft will have a "sail" one quarter the size of a footb...

  10. Solar Sailing is not Science Fiction Anymore

    NASA Technical Reports Server (NTRS)

    Alhorn, Dean C.

    2010-01-01

    Over 400 years ago Johannes Kepler envisioned the use of sunlight to propel a spacecraft. Just this year, a solar sail was deployed in orbit for the first time and proved that a spacecraft could effectively use a solar sail for propulsion. NASA's first nano-class solar sail satellite, NanoSail-D was designed and developed in only four months. Although the first unit was lost during the Falcon 1 rocket failure in 2008, the second flight unit has been refurbished and is waiting to be launched later this year. NanoSail-D will further the research into solar sail enabled spacecraft. It will be the first of several more sail enabled spacecraft to be launch in the next few years. FeatherSail is the next generation nano-class sail spacecraft being designed with the goal to prove low earth orbit operational capabilities. Future solar sail spacecraft will require novel ideas and innovative research for the continued development of space systems. One such pioneering idea is the Small Multipurpose Advanced Reconfigurable Technology (SMART) project. The SMART technology has the potential to revolutionize spacecraft avionics. Even though solar sailing is currently in its infancy, the next decade will provide great opportunities for research into sailing in outer space.

  11. Solar Sail Model Validation from Echo Trajectories

    NASA Technical Reports Server (NTRS)

    Heaton, Andrew F.; Brickerhoff, Adam T.

    2007-01-01

    The NASA In-Space Propulsion program has been engaged in a project to increase the technology readiness of solar sails. Recently, these efforts came to fruition in the form of several software tools to model solar sail guidance, navigation and control. Furthermore, solar sails are one of five technologies competing for the New Millennium Program Space Technology 9 flight demonstration mission. The historic Echo 1 and Echo 2 balloons were comprised of aluminized Mylar, which is the near-term material of choice for solar sails. Both spacecraft, but particularly Echo 2, were in low Earth orbits with characteristics similar to the proposed Space Technology 9 orbit. Therefore, the Echo balloons are excellent test cases for solar sail model validation. We present the results of studies of Echo trajectories that validate solar sail models of optics, solar radiation pressure, shape and low-thrust orbital dynamics.

  12. Electric Solar Wind Sail (E-sail) mission to asteroids

    NASA Astrophysics Data System (ADS)

    Merikallio, Sini; Janhunen, Pekka; Toivanen, Petri; Jouni Envall, M.(Tech.).

    2012-07-01

    There are an estimated one to two million asteroids of diameter over 1 km in-between the orbits of Mars and Jupiter. Impact threat, mining prospects and the understanding of solar system history make asteroids interesting objects for further in-situ studies. Electric Solar Wind Sail (E-sail) [1] technology enables touring several different asteroids with the same spacecraft. It is a propulsion technology first proposed in 2006 and currently developed with the EUs FP7 funding (http://www.electric-sailing.fi/fp7). The E-sail utilizes long, conducting, highly charged tethers to gather momentum from the solar wind ions. It does not consume any propellant and is well maneuverable. The Electric Solar Wind Sail producing 1 N of thrust at 1 AU distance from the Sun could be manufactured to weigh 100-150 kg in total. The constant acceleration gives a large advantage over traditional methods when calculated over the mission lifetime. In a ten year mission a baseline 1 N E-sail could produce 300 MNs of total impulse, Itot. As an example, such a total impulse would be able to move a 3 million ton Earth-threatening asteroid to a safer track [2]. With chemical propellant it would take 100 000 tons of fuel to achieve the same feat. Scientists and miners could have a closer look at several targets and they could decide the next target and the duration of investigations once at the vicinity of the asteroid, so the operations would be very flexible. Such a mission could characterize and map several asteroids, some with rapid fly-bys and a few chosen ones during lengthier rendezvous. [1] Janhunen, P., et. al, Electric solar wind sail: Towards test missions (Invited article), Rev. Sci. Instrum., 81, 111301, 2010. [2] Merikallio, S. and P. Janhunen, Moving an asteroid with electric solar wind sail, Astrophys. Space Sci. Trans., 6, 41-48, 2010

  13. NASA Solar Sail Propulsion Technology Development

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Montgomery, Edward E.; Young, Roy; Adams, Charles

    2007-01-01

    NASA's In-Space Propulsion Technology Program has developed the first generation of solar sail propulsion systems sufficient to accomplish inner solar system science and exploration missions. These first generation solar sails, when operational, will range in size from 40 meters to well over 100 meters in diameter and have an areal density of less than 13 grams per square meter. A rigorous, multi-year technology development effort culminated in 2005 with the testing of two different 20-m solar sail systems under thermal vacuum conditions. The first system, developed by ATK Space Systems of Goleta, California, uses rigid booms to deploy and stabilize the sail. In the second approach, L'Garde, Inc. of Tustin, California uses inflatable booms that rigidize in the coldness of space to accomplish sail deployment. This effort provided a number of significant insights into the optimal design and expected performance of solar sails as well as an understanding of the methods and costs of building and using them. In a separate effort, solar sail orbital analysis tools for mission design were developed and tested. Laboratory simulations of the effects of long-term space radiation exposure were also conducted on two candidate solar sail materials. Detailed radiation and charging environments were defined for mission trajectories outside the protection of the earth's magnetosphere, in the solar wind environment. These were used in other analytical tools to prove the adequacy of sail design features for accommodating the harsh space environment. Preceding and in conjunction with these technology efforts, NASA sponsored several mission application studies for solar sails. Potential missions include those that would be flown in the near term to study the sun and be used in space weather prediction to one that would use an evolved sail capability to support humanity's first mission into nearby interstellar space. This paper will describe the status of solar sail propulsion within

  14. Heliogyro Solar Sail Research at NASA

    NASA Technical Reports Server (NTRS)

    Wilkie, W. Keats; Warren, Jerry E.; Guerrant, Daniel V.; Lawrence, Dale A.; Gibbs, S. Chad; Dowell, Earl H.; Heaton, Andrew F.; Heaton, Andrew F.; Juang, Jer-Nan; Horta, Lucas G.; Lyle, Karen H.; Littell, Justin D.; Bryant, Robert G.; Thomson, Mark W.; Walkemeyer, Phillip E.

    2013-01-01

    The recent successful flight of the JAXA IKAROS solar sail has renewed interest within NASA in spinning solar sail concepts for high-performance solar sailing. The heliogyro solar sail, in particular, is being re-examined as a potential game-changing architecture for future solar sailing missions. In this paper, we present an overview of ongoing heliogyro technology development and feasibility assessment activities within NASA. In particular, a small-scale heliogyro solar sail technology demonstration concept will be described. We will also discuss ongoing analytical and experimental heliogyro structural dynamics and controls investigations and provide an outline of future heliogyro development work directed toward enabling a low cost heliogyro technology demonstration mission ca. 2020.

  15. Fabrication end Deployment Testing of Meter Solar Sail Quadrants for a Scaleable Square Solar Sail Ground Test System

    NASA Technical Reports Server (NTRS)

    Laue, Greg; Case, David; Moore, Jim

    2005-01-01

    In order for solar sail propulsion technologies to be considered as a viable option for a wide range of near term practical missions a predictable, stable, reliable, manufactureable, scaleable, and cost effective system must be developed and tested first on earth and then on orbit. The design and development of a Scaleable Square Solar Sail System (S^4) is well underway a t AEC-Able Engineering Co. Inc., and the design and production of the Solar Sails for this system is being carried out by SRS Technologies. In April and May of 2004 a single quadrant 10-meter system was tested at NASA LARC's vacuum chamber and a four quadrant 20-meter system has been designed and built for deployment and testing in the Spring of 2005 at NASA/Glenn Research Center's Plumb Brook Facility. SRS has developed an effective and efficient design for triangular sail quadrants that are supported are three points and provide a flat reflective surface with a high fill factor. This sail design is robust enough for deployments in a one atmosphere, one gravity environment and incorporates several advanced features including adhesiveless seaming of membrane strips, compliant edge borders to allow for film membrane cord strain mismatch without causing wrinkling and low mass (3% of total sail mass) ripstop. This paper will outline the sail design and fabrication process, the lessons learned and the resulting mature production, packaging and deployment processes that have been developed. It will also highlight the scalability of the equipment and processes that were developed to fabricate and package the sails. Based on recent experience, SRS is confidant that flight worthy solar sails in the 40-120-meter size range with areal density in the 4-5g/sq m (sail minus structure) range can be produced with existing technology. Additional film production research will lead to further reductions in film thickness to less than 1 micron enabling production of sails with areal densities as low as 20 g/sq m

  16. Graphene, the Ultimate Interstellar Solar Sail Material?

    NASA Astrophysics Data System (ADS)

    Matloff, G. L.

    Graphene (a carbon molecular monolayer) is a wonder material of great interest to materials researchers. Its molecular-layer thickness, finite fractional absorption, high melting point, and impermeability to gases coupled with the fact that doped materials, additives and multiple layers increase both fractional absorption and reflectivity indicates that it may be a superior material for application in solar-photon sailing. This paper first reviews relevant graphene physical and optical properties and then investigates the kinematics of interstellar solar sails constructed using this material. Two sail configurations are considered: thin-film probes and hollow-bodies sails. It is shown that graphene sail performance may be superior to that of beryllium sails. Less intense perihelion passes and accelerations may allow transit times to Alpha Centauri approximating a millennium. Future research should consider the interaction of graphene sails with the space environment and large-scale fabrication techniques.

  17. Similarity Rules for Scaling Solar Sail Systems

    NASA Technical Reports Server (NTRS)

    Canfield, Stephen L.; Peddieson, John; Garbe, Gregory

    2010-01-01

    Future science missions will require solar sails on the order of 200 square meters (or larger). However, ground demonstrations and flight demonstrations must be conducted at significantly smaller sizes, due to limitations of ground-based facilities and cost and availability of flight opportunities. For this reason, the ability to understand the process of scalability, as it applies to solar sail system models and test data, is crucial to the advancement of this technology. This paper will approach the problem of scaling in solar sail models by developing a set of scaling laws or similarity criteria that will provide constraints in the sail design process. These scaling laws establish functional relationships between design parameters of a prototype and model sail that are created at different geometric sizes. This work is applied to a specific solar sail configuration and results in three (four) similarity criteria for static (dynamic) sail models. Further, it is demonstrated that even in the context of unique sail material requirements and gravitational load of earth-bound experiments, it is possible to develop appropriate scaled sail experiments. In the longer term, these scaling laws can be used in the design of scaled experimental tests for solar sails and in analyzing the results from such tests.

  18. Solar sails: Modeling, estimation, and trajectory control

    NASA Astrophysics Data System (ADS)

    Rios-Reyes, Leonel

    There has been great interest in developing solar sail technology and missions by several international space agencies in recent years. However, at present there is no consensus on how one can mathematically model forces and moments acting on a solar sail. Traditional analytical models and finite element methods are not feasible for integration into a precise navigation system. This dissertation takes a step toward resolving this issue by developing tools and concepts that can be integrated into a precise solar sail navigation system. These steps are the derivation of a generalized sail model, a linear estimation method for estimating and predicting forces and moments acting on a solar sail, and a new trajectory control methodology for tracking a nominal trajectory when the sail performance exceeds the nominal design performance. The main contributions of this dissertation follow. First, the generalized sail model (GSM) is defined to analytically describe the forces and moments acting on a solar sail of arbitrary shape. The GSM is derived by performing an integration, of all the differential forces and moments acting on the sail, over the sail surface. Next, the GSM is applied to several examples to illustrate the use of the GSM's analytic equations. These examples allow comparisons of forces and moments generated by different solar sails, the computation of force derivatives, and the application of the model to orbital mechanics problems. Since it is difficult to model the sail geometry based on ground measurements; errors in the sail model are expected once the sail is deployed in space. Due to this difficulty; a least-squares estimation method for the force and moment coefficients of the GSM is derived. For realistic implementation of a sail trajectory, the deployed sail must have an excess thrust capacity. We develop and implement a control methodology for flying a nominal mission profile with such an excess capacity. Control laws for maintaining a flat, ideal

  19. Solar Sail GN and C Model Comparisons

    NASA Technical Reports Server (NTRS)

    Heaton, Andrew F.

    2004-01-01

    The Solar Sail Propulsion project is engaged in an ambitious program to raise the Technology Readiness Level of solar sails and prepare for a validation flight via a series of hardware ground demonstrations and development of a number of high fidelity simulations and models. Guidance, navigation, and control of solar sails is a key part of this effort. The large flexible structure and optical nature of solar sails create a considerable challenge for attitude control, thrust modeling, and navigation. In this paper, we present an overview and comparison of two recently delivered prototype solar sail guidance, navigation, and control software tools currently funded by the Solar Sail Propulsion project. The results of some key test cases are presented. Where possible, we also make comparisons to other software tools. We discuss the implications of the results of these comparative studies to the future direction and scope of development efforts for guidance, navigation and control software for solar sails, including the relationship to hardware test efforts such as the Thrust Vector Control Authority Demonstration.

  20. Solar sailing: mission applications and engineering challenges.

    PubMed

    McInnes, Colin R

    2003-12-15

    Solar sailing is emerging as a promising form of advanced spacecraft propulsion, which can enable exciting new space-science mission concepts. By exploiting the momentum transported by solar photons, solar sails can perform high-energy orbit-transfer manoeuvres without the need for reaction mass. Missions such as planetary-sample return, multiple small-body rendezvous and fast missions to the outer Solar System can therefore be enabled with the use of only a modest launch vehicle. In addition, new families of highly non-Keplerian orbits have been identified that are unique to solar sails, and can enable new ways of performing space-science missions. While the opportunities presented by solar sailing are appealing, engineering challenges are still to be solved before the technology finally comes to fruition. PMID:14667309

  1. Flexible Models for Solar Sail Control

    NASA Technical Reports Server (NTRS)

    Weaver Smith, Suzanne; Song, Haiping; Baker, John R.; Black, Jonathan; Muheim, Danniella M.

    2005-01-01

    Solar sails employ a unique form of propulsion, gaining momentum from incident and reflected photons. However, the momentum transferred by an individual photon is extremely small. Consequently, a solar sail must have an extremely large surface area and also be extremely light. The flexibility of the sail then must be considered when designing or evaluating control laws. In this paper, solar sail flexibility and its influence on control effectiveness is considered using idealized two-dimensional models to represent physical phenomena rather than a specific design. Differential equations of motion are derived for a distributed parameter model of a flexible solar sail idealized as a rotating central hub with two opposing flexible booms. This idealization is appropriate for solar sail designs in which the vibrational modes of the sail and supporting booms move together allowing the sail mass to be distributed along the booms in the idealized model. A reduced analytical model of the flexible response is considered. Linear feedback torque control is applied at the central hub. Two translational disturbances and a torque disturbance also act at the central hub representing the equivalent effect of deflecting sail shape about a reference line. Transient simulations explore different control designs and their effectiveness for controlling orientation, for reducing flexible motion and for disturbance rejection. A second model also is developed as a two-dimensional "pathfinder" model to calculate the effect of solar sail shape on the resultant thrust, in-plane force and torque at the hub. The analysis is then extended to larger models using the finite element method. The finite element modeling approach is verified by comparing results from a two-dimensional finite element model with those from the analytical model. The utility of the finite element modeling approach for this application is then illustrated through examples based on a full finite element model.

  2. Design Rules and Scaling for Solar Sails

    NASA Technical Reports Server (NTRS)

    Zeiders, Glenn W.

    2005-01-01

    Useful design rules and simple scaling models have been developed for solar sails. Chief among the conclusions are: 1. Sail distortions contribute to the thrust and moments primarily though the mean squared value of their derivatives (slopes), and the sail behaves like a flat sheet if the value is small. The RMS slope is therefore an important figure of merit, and sail distortion effects on the spacecraft can generally be disregarded if the RMS slope is less than about 10% or so. 2. The characteristic slope of the sail distortion varies inversely with the tension in the sail, and it is the tension that produces the principle loading on the support booms. The tension is not arbitrary, but rather is the value needed to maintain the allowable RMS slope. That corresponds to a halyard force about equal to three times the normal force on the supported sail area. 3. Both the AEC/SRS and L Garde concepts appear to be structurally capable of supporting sail sizes up to a kilometer or more with 1AU solar flux, but select transverse dimensions must be changed to do so. Operational issues such as fabrication, handling, storage and deployment will be the limiting factors.

  3. Solar Sails: Sneaking up on Interstellar Travel

    NASA Astrophysics Data System (ADS)

    Johnson, L.

    Throughout the world, government agencies, universities and private companies are developing solar sail propulsion systems to more efficiently explore the solar system and to enable science and exploration missions that are simply impossible to accomplish by any other means. Solar sail technology is rapidly advancing to support these demonstrations and missions, and in the process, is incrementally advancing one of the few approaches allowed by physics that may one day take humanity to the stars. Continuous solar pressure provides solar sails with propellantless thrust, potentially enabling them to propel a spacecraft to tremendous speeds ­ theoretically much faster than any present-day propulsion system. The next generation of sails will enable us to take our first real steps beyond the edge of the solar system, sending spacecraft out to distances of 1000 Astronomical Units, or more. In the farther term, the descendants of these first and second generation sails will augment their thrust by using high power lasers and enable travel to nearby stellar systems with flight times less than 500 years ­ a tremendous improvement over what is possible with conventional chemical rockets. By fielding these first solar sail systems, we are sneaking up on a capability to reach the stars.

  4. Solar Sail Loads, Dynamics, and Membrane Studies

    NASA Technical Reports Server (NTRS)

    Slade, K. N.; Belvin, W. K.; Behun, V.

    2002-01-01

    While a number of solar sail missions have been proposed recently, these missions have not been selected for flight validation. Although the reasons for non-selection are varied, principal among them is the lack of subsystem integration and ground testing. This paper presents some early results from a large-scale ground testing program for integrated solar sail systems. In this series of tests, a 10 meter solar sail tested is subjected to dynamic excitation both in ambient atmospheric and vacuum conditions. Laser vibrometry is used to determine resonant frequencies and deformation shapes. The results include some low-order sail modes which only can be seen in vacuum, pointing to the necessity of testing in that environment.

  5. Solar sailing - The concept made realistic

    NASA Technical Reports Server (NTRS)

    Friedman, L.; Carroll, W.; Goldstein, R.; Jacobson, R.; Kievit, J.; Landel, R.; Layman, W.; Marsh, E.; Ploszaj, R.; Rowe, W.; Ruff, W.; Stevens, J.; Stimpson, L.; Trubert, M.; Varsi, G.; Wright, J.

    1978-01-01

    The practicability of using solar sails as a means of spacecraft propulsion is discussed with reference to a Haley's comet rendezvous mission in 1981. Two types of sails are examined: square and heliogyro. Because of ease of deployment (release into space from a space shuttle, and unfolding of the blades through solar radiation pressure) the latter is preferred. Structural and mission parameters are given for the heliogyro configuration, with attention to operational temperature limits and material coefficients. A cranking orbit is described, where a sail-powered spacecraft flies first toward the sun, and then away from it in order to achieve rendezvous with a comet. Other missions using solar sails, including a back-up mission to Encke's comet in 1983, are also discussed.

  6. Electric solar wind sail mass budget model

    NASA Astrophysics Data System (ADS)

    Janhunen, P.; Quarta, A. A.; Mengali, G.

    2013-02-01

    The electric solar wind sail (E-sail) is a new type of propellantless propulsion system for Solar System transportation, which uses the natural solar wind to produce spacecraft propulsion. The E-sail consists of thin centrifugally stretched tethers that are kept charged by an onboard electron gun and, as such, experience Coulomb drag through the high-speed solar wind plasma stream. This paper discusses a mass breakdown and a performance model for an E-sail spacecraft that hosts a mission-specific payload of prescribed mass. In particular, the model is able to estimate the total spacecraft mass and its propulsive acceleration as a function of various design parameters such as the number of tethers and their length. A number of subsystem masses are calculated assuming existing or near-term E-sail technology. In light of the obtained performance estimates, an E-sail represents a promising propulsion system for a variety of transportation needs in the Solar System.

  7. Validation of Solar Sail Simulations for the NASA Solar Sail Demonstration Project

    NASA Technical Reports Server (NTRS)

    Braafladt, Alexander C.; Artusio-Glimpse, Alexandra B.; Heaton, Andrew F.

    2014-01-01

    NASA's Solar Sail Demonstration project partner L'Garde is currently assembling a flight-like sail assembly for a series of ground demonstration tests beginning in 2015. For future missions of this sail that might validate solar sail technology, it is necessary to have an accurate sail thrust model. One of the primary requirements of a proposed potential technology validation mission will be to demonstrate solar sail thrust over a set time period, which for this project is nominally 30 days. This requirement would be met by comparing a L'Garde-developed trajectory simulation to the as-flown trajectory. The current sail simulation baseline for L'Garde is a Systems Tool Kit (STK) plug-in that includes a custom-designed model of the L'Garde sail. The STK simulation has been verified for a flat plate model by comparing it to the NASA-developed Solar Sail Spaceflight Simulation Software (S5). S5 matched STK with a high degree of accuracy and the results of the validation indicate that the L'Garde STK model is accurate enough to meet the potential future mission requirements. Additionally, since the L'Garde sail deviates considerably from a flat plate, a force model for a non-flat sail provided by L'Garde sail was also tested and compared to a flat plate model in S5. This result will be used in the future as a basis of comparison to the non-flat sail model being developed for STK.

  8. Multiple NEO Rendezvous Using Solar Sail Propulsion

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Alexander, Leslie; Fabisinski, Leo; Heaton, Andy; Miernik, Janie; Stough, Rob; Wright, Roosevelt; Young, Roy

    2012-01-01

    The NASA Marshall Space Flight Center (MSFC) Advanced Concepts Office performed an assessment of the feasibility of using a near-term solar sail propulsion system to enable a single spacecraft to perform serial rendezvous operations at multiple Near Earth Objects (NEOs) within six years of launch on a small-to-moderate launch vehicle. The study baselined the use of the sail technology demonstrated in the mid-2000 s by the NASA In-Space Propulsion Technology Project and is scheduled to be demonstrated in space by 2014 as part of the NASA Technology Demonstration Mission Program. The study ground rules required that the solar sail be the only new technology on the flight; all other spacecraft systems and instruments must have had previous space test and qualification. The resulting mission concept uses an 80-m X 80-m 3-axis stabilized solar sail launched by an Athena-II rocket in 2017 to rendezvous with 1999 AO10, Apophis and 2001 QJ142. In each rendezvous, the spacecraft will perform proximity operations for approximately 30 days. The spacecraft science payload is simple and lightweight; it will consist of only the multispectral imager flown on the Near Earth Asteroid Rendezvous (NEAR) mission to 433 Eros and 253 Mathilde. Most non-sail spacecraft systems are based on the Messenger mission spacecraft. This paper will describe the objectives of the proposed mission, the solar sail technology to be employed, the spacecraft system and subsystems, as well as the overall mission profile.

  9. Empirical Model Reduction of Spinning Solar Sail

    NASA Astrophysics Data System (ADS)

    Yamazaki, Masahiko; Miyazaki, Yasuyuki

    The Spinning solar sail is expected to be a future space exploration system. Considering the dynamic deformation of the sail membrane is an indispensable factor in designing the spacecraft. But the mathematical model of the sail membrane is complex. Computational analysis is difficult and time consuming. Therefore this has a negative impact on simulation, design and control problems. The model reduction technique is required to shorten the design period. It is a necessary step in order to put the gossamer structure to practical use. In this presentation, the dynamic property of the square type spinning solar sail is revealed, and the requirements for constructing a reduction model are revealed. Then, empirical model reduction techniques are applied to gossamer structures, and the issue of constructing a low-order model is summarized.

  10. Selection and Manufacturing of Membrane Materials for Solar Sails

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G.; Seaman, Shane T.; Wilkie, W. Keats; Miyaucchi, Masahiko; Working, Dennis C.

    2013-01-01

    Commercial metallized polyimide or polyester films and hand-assembly techniques are acceptable for small solar sail technology demonstrations, although scaling this approach to large sail areas is impractical. Opportunities now exist to use new polymeric materials specifically designed for solar sailing applications, and take advantage of integrated sail manufacturing to enable large-scale solar sail construction. This approach has, in part, been demonstrated on the JAXA IKAROS solar sail demonstrator, and NASA Langley Research Center is now developing capabilities to produce ultrathin membranes for solar sails by integrating resin synthesis with film forming and sail manufacturing processes. This paper will discuss the selection and development of polymer material systems for space, and these new processes for producing ultrathin high-performance solar sail membrane films.

  11. Laboratory Facility for Simulating Solar Wind Sails

    NASA Astrophysics Data System (ADS)

    Funaki, Ikkoh; Ueno, Kazuma; Oshio, Yuya; Ayabe, Tomohiro; Horisawa, Hideyuki; Yamakawa, Hiroshi

    2008-12-01

    Magnetic sail (MagSail) is a deep space propulsion system, in which an artificial magnetic cavity captures the energy of the solar wind to propel a spacecraft in the direction leaving the sun. For a scale-model experiment of the plasma flow of MagSail, we employed a magnetoplasmadynamic arcjet as a solar wind simulator. It is observed that a plasma flow from the solar wind simulator reaches a quasi-steady state of about 0.8 ms duration after a transient phase when initiating the discharge. During this initial phase of the discharge, a blast-wave was observed to develop radially in a vacuum chamber. When a solenoidal coil (MagSail scale model) is immersed into the quasi-steady flow where the velocity is 45 km/s, and the number density is 1019 m-3, a bow shock as well as a magnetic cavity were formed in front of the coil. As a result of the interaction between the plasma flow and the magnetic cavity, the momentum of the simulated solar wind is decreased, and it is found from the thrust measurement that the solar wind momentum is transferred to the coil simulating MagSail.

  12. Laboratory Facility for Simulating Solar Wind Sails

    SciTech Connect

    Funaki, Ikkoh; Ayabe, Tomohiro; Horisawa, Hideyuki; Yamakawa, Hiroshi

    2008-12-31

    Magnetic sail (MagSail) is a deep space propulsion system, in which an artificial magnetic cavity captures the energy of the solar wind to propel a spacecraft in the direction leaving the sun. For a scale-model experiment of the plasma flow of MagSail, we employed a magnetoplasmadynamic arcjet as a solar wind simulator. It is observed that a plasma flow from the solar wind simulator reaches a quasi-steady state of about 0.8 ms duration after a transient phase when initiating the discharge. During this initial phase of the discharge, a blast-wave was observed to develop radially in a vacuum chamber. When a solenoidal coil (MagSail scale model) is immersed into the quasi-steady flow where the velocity is 45 km/s, and the number density is 10{sup 19} m-3, a bow shock as well as a magnetic cavity were formed in front of the coil. As a result of the interaction between the plasma flow and the magnetic cavity, the momentum of the simulated solar wind is decreased, and it is found from the thrust measurement that the solar wind momentum is transferred to the coil simulating MagSail.

  13. Mercury Sample Return using Solar Sails

    NASA Technical Reports Server (NTRS)

    Montgomery, Edward E.; Young, Roy M.; Adams, Charles L.

    2006-01-01

    A conventional Mercury sample return mission requires significant launch mass due to the large deltav required for the outbound and return trips, and the large mass of a planetary lander and ascent vehicle. Solar sailing can be used to reduce lander mass allocation by delivering the lander to a low, thermally safe orbit close to the terminator. Propellant mass is not an issue for solar sails so a sample can be returned relatively easily, without resorting to lengthy, multiple gravity assists. The initial Mercury sample return studies reported here were conducted under ESA contract ESTEC/16534/02/NL/NR, PI Colin McInnes, Technical Officer Peter Falkner. Updated solar sail capabilities were developed under the Ground System Demonstration program, funded by the NASA's In-Space Propulsion Technology (ISPT) Program.

  14. Station keeping of a solar sail around a Halo orbit

    NASA Astrophysics Data System (ADS)

    Farrés, Ariadna; Jorba, Àngel

    2014-01-01

    Solar sails are a concept of spacecraft propulsion that takes advantage of solar radiation pressure to propel a spacecraft. Although the thrust provided by a solar sail is small it is constant and unlimited. This offers the chance to deal with novel mission concept. In this work we want to discuss the controllability of a spacecraft around a Halo orbit by means of a solar sail. We will describe the natural dynamics for a solar sail around a Halo orbit. By natural dynamics we mean the behaviour of the trajectory of a solar sail when no control on the sail orientation is applied. We will then discuss how a sequence of changes on the sail orientation will affects the sail's trajectory, and we will use this information to derive efficient station keeping strategies. Finally we will check the robustness of these strategies including different sources of errors in our simulations.

  15. Similarity Rules for Scaling Solar Sail Systems

    NASA Technical Reports Server (NTRS)

    Canfield, Stephen L.; Beard, James W., III; Peddieson, John; Ewing, Anthony; Garbe, Greg

    2004-01-01

    Future science missions will require solar sails on the order 10,000 sq m (or larger). However, ground and flight demonstrations must be conducted at significantly smaller Sizes (400 sq m for ground demo) due to limitations of ground-based facilities and cost and availability of flight opportunities. For this reason, the ability to understand the process of scalability, as it applies to solar sail system models and test data, is crucial to the advancement of this technology. This report will address issues of scaling in solar sail systems, focusing on structural characteristics, by developing a set of similarity or similitude functions that will guide the scaling process. The primary goal of these similarity functions (process invariants) that collectively form a set of scaling rules or guidelines is to establish valid relationships between models and experiments that are performed at different orders of scale. In the near term, such an effort will help guide the size and properties of a flight validation sail that will need to be flown to accurately represent a large, mission-level sail.

  16. Attitude stability criteria of axisymmetric solar sail

    NASA Astrophysics Data System (ADS)

    Hu, Xiaosai; Gong, Shengping; Li, Junfeng

    2014-07-01

    Passive attitude stability criteria of a solar sail whose membrane surface is axisymmetric are studied in this paper under a general SRP model. This paper proves that arbitrary attitude equilibrium position can be designed through adjusting the deviation between the pressure center and the mass center of the sail. The linearized method is applied to inspect analytically the stability of the equilibrium point from two different points of views. The results show that the attitude stability depends on the membrane surface shape and area. The results of simulation with full dynamic equations confirm that the two stability criteria are effective in judging the attitude stability for axisymmetric solar sail. Several possible applications of the study are also mentioned.

  17. Multiple NEO Rendezvous Using Solar Sails

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Alexander, Leslie; Fabisinski, Leo; Heaton, Andy; Miernik, Janie; Stough, Rob; Wright, Roosevelt; Young, Roy

    2012-01-01

    Mission concept is to assess the feasibility of using solar sail propulsion to enable a robotic precursor that would survey multiple Near Earth Objects (NEOs) for potential future human visits. Single spacecraft will rendezvous with and image 3 NEOs within 6 years of launch

  18. Graphene Solar Photon Sails and Interstellar Arks

    NASA Astrophysics Data System (ADS)

    Matloff, G. L.

    2014-06-01

    A review of conceptual interstellar generation ships is followed by a presentation of optical and thermal properties of graphene and a discussion of kinematics/thermal-aspects of the solar-acceleration phase of a starship propelled by a graphene hollowbody solar-photon sail. The spacecraft departs from an initially parabolic solar orbit and the sail is oriented normal to the Sun during solar-acceleration. Perihelion is constrained to 0.1 AU because humans can tolerate ~3g for several hours without lasting effects. The 5 × 106 kg payload mass and 9.16 × 106 kg sail mass are applied as cosmic-ray shielding for the ship's 20-50 person population during the ~1,400-year cruise phase. Artificial gravity, the Coriolis Effect, closed-environment agriculture, illumination, on-board energy requirements, thermal dissipation, and hygiene/recreation are considered in a discussion of habitat design. Many concepts for mid-course trajectory correction are discussed including a new one that expels mass collected by a Cassenti toroidal ion scoop in a direction normal to the ship's trajectory. Although acceleration is affected by the unfurled sail, other options are discussed, as is the problem of protection from interstellar-dust erosion. As well as presenting the total mass budget, the conclusion reviews published variations and modifications on the generation-ship theme.

  19. Material problems in solar sail development

    NASA Technical Reports Server (NTRS)

    Steurer, W. H.

    1980-01-01

    The paper considers the solar sail principle as an effective means of space propulsion. The heliogyro configuration is discussed including the hub structures, the flap-hinge brace assembly, and the blade. The material requirements of the sail film made of metallized polymers, the tendons produced from a polymer-graphite fiber composite, and battens constructed of graphite/epoxy tubings are considered, noting that not all of these materials were readily available. It was concluded that the primary material problems are the environmental degradation of polymer films, the meteoroid hazard, and the production capacity for large polymer film quantities.

  20. A Study of Possible Solar Sail Applications for Mars Missions

    NASA Technical Reports Server (NTRS)

    Percy, Thomas K.; Taylor, Travis; Powell, T. Conley

    2004-01-01

    A study was performed in conjunction with the In Space Technology Investment Area of NASA's Marshall Space Flight Center to investigate potential applications of solar sails to Mars missions. While solar sails have been proposed as possible candidates for several missions, including Geostorm and a Polar Observer mission, Mars has often been overlooked as a potential destination. It was found that solar sails may have potential in Mars observation missions with smaller payloads. Sail aerocapture maneuvers also show an improvement in payload delivery capability. This study has shown that solar sail spacecraft rival chemical interplanetary probes to Mars and may have applications in future Mars exploration.

  1. Orbital dynamics of Sun-facing solar sails under the constraint of constant sail temperature

    NASA Astrophysics Data System (ADS)

    Yamakawa, Hiroshi

    2006-03-01

    The orbital dynamics of Sun-facing solar sails is investigated considering a constraint of constant sail temperature at the limit of the sail material. Although solar sails can normally be articulated so as to provide thrust with both a transverse and radial component, a Sunfacing attitude with the center of solar pressure behind the center of gravity may be preferred for very large or gossamer sails in order to achieve Sun-facing attitude stability. The proposed Sun-facing solar sails are applicable to space weather and geo-storm warning missions for monitoring the inner solar system environment by in-situ measurement of solar wind plasma and high-energy particle events. Constraining the temperature of the sail to the temperature limit of the sail material allows the innermost circular orbits to be attained thereby maximizing scientific returns. The stability of the heliocentric circular orbit under such radial thrust with the constant temperature constraint is investigated, and the stability conditions are obtained as functions of the radius of circular orbit and the solar sail lightness number accounting for optical/thermal properties.

  2. Spacecraft Solar Sails Containing Electrodynamic Tethers

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Matloff, Greg

    2005-01-01

    A report discusses a proposal to use large, lightweight solar sails embedded with electrodynamic tethers (essentially, networks of wires) to (1) propel robotic spacecraft to distant planets, then (2) exploit the planetary magnetic fields to capture the spacecraft into orbits around the planets. The purpose of the proposal is, of course, to make it possible to undertake long interplanetary missions without incurring the large cost and weight penalties of conventional rocket-type propulsion systems. Through transfer of momentum from reflected solar photons, a sail would generate thrust outward from the Sun. Upon arrival in the vicinity of a planet, the electrodynamic tethers would be put to use: Motion of the spacecraft across the planetary magnetic field would induce electric currents in the tether wires, giving rise to an electromagnetic drag force that would be exploited to brake the spacecraft for capture into orbit. The sail with embedded tethers would be made to spin to provide stability during capture. Depending upon the requirements of a particular application, it could be necessary to extend the tether to a diameter greater than that of the sail.

  3. Design of a Solar Sail Mission to Mars

    NASA Technical Reports Server (NTRS)

    Eastridge, Richard; Funston, Kerry; Okia, Aminat; Waldrop, Joan; Zimmerman, Christopher

    1989-01-01

    An evaluation of the design of the solar sail includes key areas such as structures, sail deployment, space environmental effects, materials, power systems, telemetry, communications, attitude control, thermal control, and trajectory analysis. Deployment and material constraints determine the basic structure of the sail, while the trajectory of the sail influences the choice of telemetry, communications, and attitude control systems. The thermal control system of the sail for the structures and electronics takes into account the effects of the space environment. Included also are a cost and weight estimate for the sail.

  4. Solar Sail Propulsion: Enabling New Capabilities for Heliophysics

    NASA Technical Reports Server (NTRS)

    Johnson, L.; Young, R.; Alhorn, D.; Heaton, A.; Vansant, T.; Campbell, B.; Pappa, R.; Keats, W.; Liewer, P. C.; Alexander, D.; Wawrzyniak, G.; Ayon, J.; Burton, R.; Carroll, D.; Matloff, G.; Kezerashvili, R. Ya.

    2010-01-01

    Solar sails can play a critical role in enabling solar and heliophysics missions. Solar sail technology within NASA is currently at 80% of TRL-6, suitable for an in-flight technology demonstration. It is conceivable that an initial demonstration could carry scientific payloads that, depending on the type of mission, are commensurate with the goals of the three study panels of the 2010 Heliophysics Survey. Follow-on solar sail missions, leveraging advances in solar sail technology to support Heliophysics Survey goals, would then be feasible. This white paper reports on a sampling of missions enabled by solar sails, the current state of the technology, and what funding is required to advance the current state of technology such that solar sails can enable these missions

  5. Mars Sample Return Using Solar Sail Propulsion

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

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

  6. Venus round trip using solar sail

    NASA Astrophysics Data System (ADS)

    Zhu, KaiJian; Zhang, RongZhi; Xu, Dong; Wang, JiaSong; Li, ShaoMin

    2012-08-01

    Trajectory optimization and simulation is performed for Venus round trip (VeRT) mission using solar sail propulsion. Solar gravity is included but atmospheric drag and shadowing effects are neglected in the planet-centered escape and capture stages. The spacecraft starts from the Geostationary orbit (GEO) at a predetermined time to prepare a good initial condition for the Earth-Venus transfer, although the launch window is not an issue for spacecraft with solar sails. The Earth-Venus phase and the return trip are divided into three segments. Two methods are adopted to maintain the mission trajectory for the VeRT mission and then compared through a numerical simulation. According to the first approach, Planet-centered and heliocentric maneuvers are modeled using a set of blended analytical control laws instead of the optimal control techniques. The second procedure is the Direct Attitude Angle Optimization in which the attitude angles of the solar sail are adopted as the optimization variables during the heliocentric transfer. Although neither of the two methods guarantees a globally optimal trajectory, they are more efficient and will produce a near-optimal solution if employed properly. The second method has produced a better result for the minimum-time transfer of the VeRT mission demonstrating the effectiveness of the methods in the preliminary design of the complex optimal interplanetary orbit transfers.

  7. Design Considerations for an Integrated Solar Sail Diagnostics System

    NASA Technical Reports Server (NTRS)

    Jenkins, Christopher H. M.; Gough, Aaron R.; Pappa, Richard S.; Carroll, Joe; Blandino, Joseph R.; Miles, Jonathan J.; Rakoczy, John

    2004-01-01

    Efforts are continuing under NASA support to improve the readiness level of solar sail technology. Solar sails have one of the best chances to be the next gossamer spacecraft flown in space. In the gossamer spacecraft community thus far, solar sails have always been considered a "low precision" application compared with, say, radar or optical devices. However, as this paper shows, even low precision gossamer applications put extraordinary demands on structural measurement systems if they are to be traceable to use in space.

  8. Space Environmental Effects on Candidate Solar Sail Materials

    NASA Technical Reports Server (NTRS)

    Edwards, David L.; Nehls, Mary; Semmel, Charles; Hovater, Mary; Gray, Perry; Hubbs, Whitney; Wertz, George

    2004-01-01

    The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) continues research into the utilization of photonic materials for spacecraft propulsion. Spacecraft propulsion, using photonic materials, will be achieved using a solar sail. A solar sail operates on the principle that photons, originating from the sun, impart pressure to the sail and therefore provide a source for spacecraft propulsion. The pressure imparted ot a solar sail can be increased, up to a factor of two, if the sun-facing surface is perfectly reflective. Therefore, these solar sails are generally composed of a highly reflective metallic sun-facing layer, a thin polymeric substrate and occasionally a highly emissive back surface. Near term solar sail propelled science missions are targeting the Lagrange point 1 (L1) as well as locations sunward of L1 as destinations. These near term missions include the Solar Polar Imager and the L1 Diamond. The Environmental Effects Group at NASA's Marshall Space Flight Center (MSFC) continues to actively characterize solar sail material in preparation for these near term solar sail missions. Previous investigations indicated that space environmental effects on sail material thermo-optical properties were minimal and would not significantly affect the propulsion efficiency of the sail. These investigations also indicated that the sail material mechanical stability degrades with increasing radiation exposure. This paper will further quantify the effect of space environmental exposure on the mechanical properties of candidate sail materials. Candidate sail materials for these missions include Aluminum coated Mylar, Teonex, and CP1 (Colorless Polyimide). These materials were subjected to uniform radiation doses of electrons and protons in individual exposures sequences. Dose values ranged from 100 Mrads to over 5 Grads. The engineering performance property responses of thermo-optical and mechanical properties were characterized

  9. Solar Sail Material Performance Property Response to Space Environmental Effects

    NASA Technical Reports Server (NTRS)

    Edwards, David L.; Semmel, Charles; Hovater, Mary; Nehls, Mary; Gray, Perry; Hubbs, Whitney; Wertz, George

    2004-01-01

    The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) continues research into the utilization of photonic materials for spacecraft propulsion. Spacecraft propulsion, using photonic materials, will be achieved using a solar sail. A solar sail operates on the principle that photons, originating from the sun, impart pressure to the sail and therefore provide a source for spacecraft propulsion. The pressure imparted to a solar sail can be increased, up to a factor of two, if the sun-facing surface is perfectly reflective. Therefore, these solar sails are generally composed of a highly reflective metallic sun-facing layer, a thin polymeric substrate and occasionally a highly emissive back surface. Near term solar sail propelled science missions are targeting the Lagrange point 1 (Ll) as well as locations sunward of L1 as destinations. These near term missions include the Solar Polar Imager and the L1 Diamond. The Environmental Effects Group at NASA s Marshall Space Flight Center (MSFC) continues to actively characterize solar sail material in preparation for these near term solar sail missions. Previous investigations indicated that space environmental effects on sail material thermo-optical properties were minimal and would not significantly affect the propulsion efficiency of the sail. These investigations also indicated that the sail material mechanical stability degrades with increasing radiation exposure. This paper will further quantify the effect of space environmental exposure on the mechanical properties of candidate sail materials. Candidate sail materials for these missions include Aluminum coated Mylar[TM], Teonex[TM], and CPl (Colorless Polyimide). These materials were subjected to uniform radiation doses of electrons and protons in individual exposures sequences. Dose values ranged from 100 Mrads to over 5 Grads. The engineering performance property responses of thermo-optical and mechanical properties were

  10. Solar Sail Attitude Control Performance Comparison

    NASA Technical Reports Server (NTRS)

    Bladt, Jeff J.; Lawrence, Dale A.

    2005-01-01

    Performance of two solar sail attitude control implementations is evaluated. One implementation employs four articulated reflective vanes located at the periphery of the sail assembly to generate control torque about all three axes. A second attitude control configuration uses mass on a gimbaled boom to alter the center-of-mass location relative to the center-of-pressure producing roll and pitch torque along with a pair of articulated control vanes for yaw control. Command generation algorithms employ linearized dynamics with a feedback inversion loop to map desired vehicle attitude control torque into vane and/or gimbal articulation angle commands. We investigate the impact on actuator deflection angle behavior due to variations in how the Jacobian matrix is incorporated into the feedback inversion loop. Additionally, we compare how well each implementation tracks a commanded thrust profile, which has been generated to follow an orbit trajectory from the sun-earth L1 point to a sub-L1 station.

  11. Solar sail attitude dynamics and control

    NASA Technical Reports Server (NTRS)

    Rodriguez, G.; Marsh, E. L.; Gunter, S. M.

    1977-01-01

    This paper describes some results of an attitude dynamics and control study for a solar sailing vehicle. This type of vehicle is currently under study and evaluation at JPL and has very high potential for interplanetary missions in and beyond the 1980s. Crucial to the success of such a vehicle would be the performance of its onboard attitude control system. Because of the vehicle's large size and its flexibility, vehicle deformations may have a potential for causing a degradation in vehicle performance. It may therefore be necessary for the control system to take into account the vehicle deformations as well as its rigid-body motions. Distributed parameter system analysis techniques are used in the paper to study certain fundamental aspects of such a control system for the sail vehicle. The techniques can, however, be more generally applicable to other large flexible vehicles.

  12. Parametric Studies of Square Solar Sails Using Finite Element Analysis

    NASA Technical Reports Server (NTRS)

    Sleight, David W.; Muheim, Danniella M.

    2004-01-01

    Parametric studies are performed on two generic square solar sail designs to identify parameters of interest. The studies are performed on systems-level models of full-scale solar sails, and include geometric nonlinearity and inertia relief, and use a Newton-Raphson scheme to apply sail pre-tensioning and solar pressure. Computational strategies and difficulties encountered during the analyses are also addressed. The purpose of this paper is not to compare the benefits of one sail design over the other. Instead, the results of the parametric studies may be used to identify general response trends, and areas of potential nonlinear structural interactions for future studies. The effects of sail size, sail membrane pre-stress, sail membrane thickness, and boom stiffness on the sail membrane and boom deformations, boom loads, and vibration frequencies are studied. Over the range of parameters studied, the maximum sail deflection and boom deformations are a nonlinear function of the sail properties. In general, the vibration frequencies and modes are closely spaced. For some vibration mode shapes, local deformation patterns that dominate the response are identified. These localized patterns are attributed to the presence of negative stresses in the sail membrane that are artifacts of the assumption of ignoring the effects of wrinkling in the modeling process, and are not believed to be physically meaningful. Over the range of parameters studied, several regions of potential nonlinear modal interaction are identified.

  13. GeoSail: Exploring the magnetosphere using a low-cost solar sail

    NASA Astrophysics Data System (ADS)

    Macdonald, Malcolm; McInnes, Colin; Alexander, David; Sandman, Anne

    2006-10-01

    GeoSail is a small, low cost, innovative mission designed to exploit the versatility of solar sail propulsion for the exploration of magnetic reconnection and electron dynamics in the Earth's magnetotail. The GeoSail mission requires only a very low performance solar sail to precess the major axis of an otherwise inertially fixed orbit, thus maintaining payload alignment within the geomagnetic tail. This constant rotation enables a near continuous observation window with the opportunity to probe the rapid dynamic evolution of energetic particle distributions in this critical region of geospace. An end-to-end system design study has been concluded and the key performance requirements identified. The level of solar sail performance required for GeoSail is typical of that currently being discussed within Europe for a near-term technology demonstration mission. GeoSail is therefore capable of providing both technology validation within the cost restrictions of a SMART mission while also returning unique science data from a first solar sail mission.

  14. Preliminary Solar Sail Design and Fabrication Assessment: Spinning Sail Blade, Square Sail Sheet

    NASA Technical Reports Server (NTRS)

    Daniels, J. B.; Dowdle, D. M.; Hahn, D. W.; Hildreth, E. N.; Lagerquist, D. R.; Mahagnoul, E. J.; Munson, J. B.; Origer, T. F.

    1977-01-01

    The designs and fabrication methods, equipment, facilities, economics, and schedules, for the square sail sheet alternate are evaluated. The baseline for the spinning sail blade design and related fabrication issues are assessed.

  15. Optical Diagnostic System for Solar Sails: Phase 1 Final Report

    NASA Technical Reports Server (NTRS)

    Pappa, Richard S.; Blandino, Joseph R.; Caldwell, Douglas W.; Carroll, Joseph A.; Jenkins, Christopher H. M.; Pollock, Thomas C.

    2004-01-01

    NASA's In-Space Propulsion program recently selected AEC-ABLE Engineering and L'Garde, Inc. to develop scale-model solar sail hardware and demonstrate its functionality on the ground. Both are square sail designs with lightweight diagonal booms (<100 g/m) and ultra-thin membranes (<10 g/sq m). To support this technology, the authors are developing an integrated diagnostics instrumentation package for monitoring solar sail structures such as these in a near-term flight experiment. We refer to this activity as the "Optical Diagnostic System (ODS) for Solar Sails" project. The approach uses lightweight optics and photogrammetric techniques to measure solar sail membrane and boom shape and dynamics, thermography to map temperature, and non-optical sensors including MEMS accelerometers and load cells. The diagnostics package must measure key structural characteristics including deployment dynamics, sail support tension, boom and sail deflection, boom and sail natural frequencies, sail temperature, and sail integrity. This report summarizes work in the initial 6-month Phase I period (conceptual design phase) and complements the final presentation given in Huntsville, AL on January 14, 2004.

  16. NASA's Next Solar Sail: Lessons Learned from NanoSail - D2

    NASA Technical Reports Server (NTRS)

    Katan, Chelsea

    2012-01-01

    NanoSail-D2 unfurled January 17th, 2011 and commenced a nine month Low Earth Orbit path to reentry to evaluate a sail's capacity to deploy in space and deorbit satellites. The orbit was strongly affected by variables including but not limited to: initial attitude, orbit lighting, solar radiation pressure, aerodynamic drag, gravity, and Center of Pressure offsets. The effects of these variables were evaluated through a 3-DOF rigid body simulation. The sail experienced stability in orbits which were continuously lit, i.e. did not orbit behind Earth. Probable drag area experienced by the sail for the mission is also estimated from orbital data and compared to the attitude simulation results. Analysis focuses on sail behavior in full lighting conditions to establish the limits of the sails stability in full lighting. Solar radiation pressure, aerodynamic drag, and gravity torque effects are described. Lastly, a reasonable upper bound on the variation of the Center of Pressure from the geometric center of the sail plane is established. Each of these results contributes to the design requirements for future solar sails.

  17. NanoSail-D: The First Flight Demonstration of Solar Sails for Nanosatellites

    NASA Technical Reports Server (NTRS)

    Whorton, Mark; Heaton, Andy; Pinson, Robin; Laue, Greg; Adams, Charles L.

    2008-01-01

    The NanoSail-D mission is currently scheduled for launch onboard a Falcon Launch Vehicle in the late June 2008 timeframe. The NanoSail-D, a CubeSat-class satellite, will consist of a sail subsystem stowed in a Cubesat 2U volume integrated with a CubeSat 1U volume bus provided by the NASA Ames Research Center (ARC). Shortly after deployment of the NanoSail-D from a Poly Picosatellite Orbital Deployer (P-POD) ejection system, the solar sail will deploy and mission operations will commence. This demonstration flight has two primary mission objectives: 1) to successfully stow and deploy the sail and 2) to demonstrate de-orbit functionality. Given a nearterm opportunity for launch, the project was met with the challenge of delivering the flight hardware in approximately six months, which required a significant constraint on flight system functionality. As a consequence, passive attitude stabilization will be achieved using permanent magnets to de-tumble and orient the body with the magnetic field lines and then rely on atmospheric drag to passively stabilize the sailcraft in an essentially maximum drag attitude. This paper will present an introduction to solar sail propulsion systems, overview the NanoSail-D spacecraft, describe the performance analysis for the passive attitude stabilization, and present a prediction of flight data results from the mission.

  18. Thermal control of a solar sail. [for Halley's Comet rendezvous

    NASA Technical Reports Server (NTRS)

    Stimpson, L. D.; Greenfield, M. L.; Jaworski, W.; Wolf, F.

    1978-01-01

    Thermal control concepts for the square and the heliogyro solar sail designs under consideration for a Halley's Comet rendezvous mission are presented. The mission, involving a 1982 launch, navigation to a 0.25-AU cranking orbit about the sun in order to develop a retrograde orbit, and rendezvous with the comet in 1986, would subject surfaces of the sail vehicle to solar constant values ranging from 16 to 0.1. A highly reflective coating to produce propulsive force is needed for one surface of the sail, while the other surface requires a highly emittive coating. The problem of maintaining the sail wrinkle-free is discussed.

  19. Sail film materials and supporting structure for a solar sail, a preliminary design, volume 4

    NASA Technical Reports Server (NTRS)

    Rowe, W. M. (Editor)

    1978-01-01

    Solar sailing technology was examined in relation to a mission to rendezvous with Halley's Comet. Development of an ultra-light, highly reflecting material system capable of operating at high solar intensity for long periods of time was emphasized. Data resulting from the sail materials study are reported. Topics covered include: basic film; coatings and thermal control; joining and handling; system performance; and supporting structures assessment for the heliogyro.

  20. Development of Deployment System for Small Size Solar Sail Mission

    NASA Astrophysics Data System (ADS)

    Mori, Osamu; Sawada, Hirotaka; Hanaoka, Fuminori; Kawaguchi, Junichiro; Shirasawa, Yoji; Sugita, Masayuki; Miyazaki, Yasuyuki; Sakamoto, Hiraku; Funase, Ryu

    The Japan Aerospace Exploration Agency (JAXA) is studying the feasibility of using the solar power sail as a new propulsion engine for deep space exploration missions. In this paper, the sail shape and equipment layout for missions utilizing small-sized solar power sails are proposed. The two-stage deployment method of the sail is also proposed. The sail need to be deployed statically at the first stage, and two types of deployment mechanisms are introduced. On the other hand the second stage of the deployment can be performed dynamically, and the oscillating motion of the membrane is converged by tethers connecting the membrane to the main body. The deployment motions are analyzed by numerical simulations using multi-particle models in order to verify the deployment. They are compared with the results calculated by finite element method models. The numerical simulation results are discussed from the technological viewpoint of the sail deployment dynamics and mechanisms.

  1. Solar sail surfing along families of equilibrium points

    NASA Astrophysics Data System (ADS)

    Farrés, Ariadna; Jorba, Àngel

    2008-07-01

    We have considered the planar circular RTBP + solar radiation pressure to model the movement of a solar sail in the Earth-Sun system. It is known that for a fixed value of the sail lightness number this model has three 1-parametric families of equilibria parametrised by the sail orientation. Most of these fixed points are unstable and require a control strategy to keep a sail close to them. We have studied the linear dynamic around them and how it varies when the sail orientation is changed. We have used this information to derive strategies to move along these families and control the trajectory of the sail close to a given fixed point. Finally, we have tested our strategies for a particular mission.

  2. Ground Deployment Demonstration and Material Testing for Solar Sail

    NASA Astrophysics Data System (ADS)

    Huang, Xiaoqi; Cheng, Zhengai; Liu, Yufei; Wang, Li

    2016-07-01

    Solar Sail is a kind of spacecraft that can achieve extremely high velocity by light pressure instead of chemical fuel. The great accelerate rely on its high area-to-mass ratio. So solar sail is always designed in huge size and it use ultra thin and light weight materials. For 100-meter class solar sail, two key points must be considered in the design process. They are fold-deployment method, and material property change in space environment. To test and verify the fold-deployment technology, a 8*8m principle prototype was developed. Sail membrane folding in method of IKAROS, Nanosail-D , and new proposed L-shape folding pattern were tested on this prototype. Their deployment properties were investigated in detail, and comparisons were made between them. Also, the space environment suitability of ultra thin polyimide films as candidate solar sail material was analyzed. The preliminary test results showed that membrane by all the folding method could deploy well. Moreover, sail membrane folding by L-shape pattern deployed more rapidly and more organized among the three folding pattern tested. The mechanical properties of the polyimide had no significant change after electron irradiation. As the preliminary research on the key technology of solar sail spacecraft, in this paper, the results of the study would provide important basis on large-scale solar sail membrane select and fold-deploying method design.

  3. Electron Radiation Effects on Candidate Solar Sail Material

    NASA Technical Reports Server (NTRS)

    Edwards, David L.; Hollerman, William A.; Hubbs, Whitney S.; Gray, Perry A.; Wertz, George E.; Hoppe, David T.; Nehls, Mary K.; Semmel, Charles L.

    2003-01-01

    Solar sailing is a unique form of propulsion where a spacecraft gains momentum from incident photons. Solar sails are not limited by reaction mass and provide continual acceleration, reduced only by the lifetime of the lightweight film in the space environment and the distance to the Sun. Once thought to be difficult or impossible, solar sailing has come out of science fiction and into the realm of possibility. Any spacecraft using this propulsion method would need to deploy a thin sail that could be as large as many kilometers in extent. The availability of strong, ultra lightweight, and radiation resistant materials will determine the future of solar sailing. The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) is concentrating research into the utilization of ultra lightweight materials for spacecraft propulsion. The Space Environmental Effects Team at MSFC is actively characterizing candidate solar sail material to evaluate the thermo-optical and mechanical properties after exposure to space environmental effects. This paper will describe the irradiation of candidate solar sail materials to energetic electrons, in vacuum, to determine the hardness of several candidate sail materials.

  4. Control of large angle maneuvers for the flexible solar sail

    NASA Astrophysics Data System (ADS)

    Zhang, Jin; Zhai, Kun; Wang, TianShu

    2011-04-01

    Solar sail is a new type of spacecraft for deep space exploration, which flies by the pressure of sunlight. The attitude of the sail determines its orbit, so altitude control plays an important role in the mission. However, the large flexible structure leads to some difficulty in attitude control. This paper establishes the reduced dynamic model of a flexible solar sail with foreshortening deformation, and coupling with its attitude and vibration. As usual, large angle maneuvering will lead to the vibration of flexible structure, so the time optimal control of solar sail maneuvering is considered. Bang-Bang control of the solar sail generates large amplitude and sustained vibration, while the combined control based on input shaping can eliminate the vibration efficiently. With the comparison of two reduced models, it is demonstrated that the choice of two models depends on the attention to the stretching deformation.

  5. Dynamical analysis of a spinning solar sail

    NASA Astrophysics Data System (ADS)

    Gong, Shengping; Li, Junfeng; Zhu, Kaijian

    2011-12-01

    This paper discusses the orbit and attitude dynamics of a solar sail, and gives the sufficient conditions of a stable orbit and attitude coupled system. The stability of the coupled system is determined by the orbit stability and attitude stability. Based on the sufficient conditions, a spin-stabilized solar sail of cone configuration is proposed to evolve in the heliocentric displaced orbit. For this kind of configuration, the attitude is always stable by spinning itself. The orbit stability depends on the orbit parameters of the heliocentric displaced orbit, the ratio of the orbit radius to displaced distance and orbit angular velocity. If the center of mass and center of pressure overlap, it can be proved that the coupled system is stable when the orbit parameters are chosen in the stable region. When the center of mass and center of pressure offset exists, the stability of the coupled system can not be judged. A numerical example is given and the result shows that both the orbit and attitude are stable for the case.

  6. Charged Particle Effects on Solar Sails - An Overview

    NASA Technical Reports Server (NTRS)

    Garrett, Henry B.; Minow, Joseph I.

    2004-01-01

    The NASA In-Space Propulsion Program is currently sponsoring a comprehensive look at the effects of the charged particle environment on the first generation of Solar Sail propulsion systems. As part of this, a joint NASA MSFC/JPL team is investigating the effects of spacecraft charging on the preliminary ISP Solar Sail mission designs. This paper will begin by reviewing the plasma environments being proposed for such missions-these range from the ambient solar wind at approximately 1 AU in the ecliptic plane, approximately 0.5 AU solar-polar orbit, and geosynchronous orbit. Following a discussion of the critical design issues associated with Solar Sails from a charging standpoint, a simple Sail configuration for modeling purposes will be presented. Results for the various environments will be illustrated in terms of the estimated surface potentials for the Solar Sail using the NASCAP-2K charging analysis program. Based on these potentials, representative plasma flow fields and potential contours surrounding the Solar Sail will then be presented. The implications of these results--the surface potentials and plasma flow--will be discussed in the context of their effects on Solar Sail operations and structural configurations.

  7. Solar and Drag Sail Propulsion: From Theory to Mission Implementation

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Alhorn, Dean; Boudreaux, Mark; Casas, Joe; Stetson, Doug; Young, Roy

    2014-01-01

    Solar and drag sail technology is entering the mainstream for space propulsion applications within NASA and around the world. Solar sails derive propulsion by reflecting sunlight from a large, mirror- like sail made of a lightweight, reflective material. The continuous sunlight pressure provides efficient primary propulsion without the expenditure of propellant or any other consumable, allowing for very high V maneuvers and long-duration deep space exploration. Drag sails increase the aerodynamic drag on Low Earth Orbit (LEO) spacecraft, providing a lightweight and relatively inexpensive approach for end-of-life deorbit and reentry. Since NASA began investing in the technology in the late 1990's, significant progress has been made toward their demonstration and implementation in space. NASA's Marshall Space Flight Center (MSFC) managed the development and testing of two different 20-m solar sail systems and rigorously tested them under simulated space conditions in the Glenn Research Center's Space Power Facility at Plum Brook Station, Ohio. One of these systems, developed by L'Garde, Inc., is planned for flight in 2015. Called Sunjammer, the 38m sailcraft will unfurl in deep space and demonstrate solar sail propulsion and navigation as it flies to Earth-Sun L1. In the interim, NASA MSFC funded the NanoSail-D, a subscale drag sail system designed for small spacecraft applications. The NanoSail-D flew aboard the Fast Affordable Science and Technology SATellite (FASTSAT) in 2010, also developed by MSFC, and began its mission after it was was ejected from the FASTSAT into Earth orbit, where it remained for several weeks before deorbiting as planned. NASA recently selected two small satellite missions as part of the Advanced Exploration Systems (AES) Program, both of which will use solar sails to enable their scientific objectives. Lunar Flashlight, managed by JPL, will search for and map volatiles in permanently shadowed Lunar craters using a solar sail as a gigantic

  8. Asteroid body-fixed hovering using nonideal solar sails

    NASA Astrophysics Data System (ADS)

    Zeng, Xiang-Yuan; Jiang, Fang-Hua; Li, Jun-Feng

    2015-04-01

    The problem of body-fixed hovering over an asteroid using a compact form of nonideal solar sails with a controllable area is investigated. Nonlinear dynamic equations describing the hovering problem are constructed for a spherically symmetric asteroid. Numerical solutions of the feasible region for body-fixed hovering are obtained. Different sail models, including the cases of ideal, optical, parametric and solar photon thrust, on the feasible region is studied through numerical simulations. The influence of the asteroid spinning rate and the sail area-to-mass ratio on the feasible region is discussed. The required orientations for the sail and their corresponding variable lightness numbers are given for different hovering radii to identify the feasible region of the body-fixed hovering. An attractive scenario for a mission is introduced to take advantage of solar sail hovering.

  9. Solar Sail Material Performance Property Response to Space Environmental Effects

    NASA Technical Reports Server (NTRS)

    Edwards, David L.; Semmel, Charles; Hovater, Mary; Nehls, Mary; Gray, Perry; Hubbs, Whitney; Wertz, George

    2004-01-01

    The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) continues research into the utilization of photonic materials for spacecraft propulsion. Spacecraft propulsion, using photonic materials, will be achieved using a solar sail. A solar sail operates on the principle that photons, originating from the sun, impart pressure to the sail and therefore provide a source for spacecraft propulsion. The pressure imparted to a solar sail can be increased, up to a factor of two if the sun-facing surface is perfectly reflective. Therefore, these solar sails are generally composed of a highly reflective metallic sun-facing layer, a thin polymeric substrate and occasionally a highly emissive back surface. Near term solar sail propelled science missions are targeting the Lagrange point 1 (L1) as well as locations sunward of L1 as destinations. These near term missions include the Solar Polar Imager' and the L1 Diamond '. The Environmental Effects Group at NASA's Marshall Space Fliglit Center (MSFC) continues to actively characterize solar sail material in preparation for these near term solar sail missions. Previous investigations indicated that space environmental effects on sail material thermo-optical properties were minimal and would not significantly affect the propulsion efficiency of the sail3-'. These investigations also indicated that the sail material mechanical stability degrades with increasing radiation exposure. This paper will further quantify the effect of space environmental exposure on the mechanical properties of candidate sail materials. Candidate sail materials for these missions include Aluminum coated Mylar TM, Teonexm, and CP1 (Colorless Polyimide). These materials were subjected to uniform radiation doses of electrons and protons in individual exposures sequences. Dose values ranged from 100 Mrads to over 5 Grads. The engineering performance property responses of thermo-optical and mechanical properties were

  10. Attitude Dynamics and Control of Solar Sails

    NASA Astrophysics Data System (ADS)

    Sperber, Evan

    Solar sails are space vehicles that rely on solar radiation pressure in order to generate forces for thrust and attitude control torques. They exhibit characteristics such as large moments of inertia, fragility of various system components, and long mission durations that make attitude control a particularly difficult engineering problem. Thrust vector control (TVC) is a family of sailcraft attitude control techniques that is on a short list of strategies thought to be suitable for the primary attitude control of solar sails. Every sailcraft TVC device functions by manipulating the relative locations of the composite mass center (cm) of the sailcraft and the center of pressure (cp) of at least one of its reflectors. Relative displacement of these two points results in body torques that can be used to steer the sailcraft. This dissertation presents a strategy for the large-angle reorientation of a sailcraft using TVC. Two forms of TVC, namely the panel and ballast mass translation methods are well represented in the literature, while rigorous studies regarding a third form, gimballed mass rotation, are conspicuously absent. The gimballed mass method is physically realized by placing a ballast mass, commonly the sailcraft's scientific payload, at the tip of a gimballed boom that has its base fixed at some point on the sailcraft. A TVC algorithm will then strategically manipulate the payload boom's gimbal angles, thereby changing the projection of the sailcraft cm in the plane of the sail. This research demonstrates effective three-axis attitude control of a model sailcraft using numerical simulation of its nonlinear equations of motion. The particular TVC algorithm developed herein involves two phases---the first phase selects appropriate gimbal rates with the objective that the sailcraft be placed in the neighborhood of its target orientation. It was discovered, however that concomitantly minimizing attitude error as well as residual body rate was not possible using

  11. Testing of a 10-meter Quadrant Solar Sail

    NASA Technical Reports Server (NTRS)

    Gaspar, James L.; Mann, Troy; Behun, Vaughn; Macy, Brian; Barker, Peter; Murphy, David

    2006-01-01

    The purpose of this paper is to address the technical challenges and requirements of modal testing a solar sail system (Fig. 1). Specific objectives of this work are to investigate the effectiveness (i.e. accuracy, precision, repeatability, etc.) of laser vibrometer measurements obtained on solar sail components (i.e. sail membrane quadrant and masts) actuated with various excitation methods in vacuum conditions. Results from this work will be used to determine the appropriate test technique for testing large scale full quadrant flight-like solar sail system hardware in vacuum conditions. This paper will focus on the dynamic tests conducted in-vacuum on a 10-meter solar sail quadrant development by AEC-ABLE as part of a ground demonstrator system development program funded by NASA's In-Space Propulsion program. One triangular shaped quadrant of a solar sail membrane (Fig. 2) was modal tested in a 1 Torr vacuum environment using various excitation techniques including, shaker excitation through the masts, magnetic excitation (Ref. 3), and surface-bonded piezoelectric patch actuators (Ref. 4 & 5). The excitation methods are evaluated for their applicability to in-vacuum ground testing and their traceability to the development of on-orbit flight test techniques. The solar sail masts (Fig. 3) were also tested in ambient atmospheric conditions and vacuum using various excitation techniques and these methods will also be assessed for their ground test capabilities and traceability to on-orbit flight testing.

  12. A practical six-degree of freedom solar sail dynamics model for optimizing solar sail trajectories with torque constraints

    NASA Technical Reports Server (NTRS)

    Lisano, Michael E.

    2004-01-01

    Controlled flight of a solar sail-propelled spacecraft ('sailcraft') is a six-degree-of-freedom dynamics problem. Current state-of-the-art tools that simulate and optimize the trajectories flown by sailcraft do not treat the full kinetic (i.e. force and torque-constrained) motion, instead treating a discrete history of commanded sail attitudes, and either neglecting the sail attitude motion over an integration timestep, or treating the attitude evolution kinematically with a spline or similar treatment. The present paper discusses an aspect of developing a next generation sailcraf trajectory designing optimization tool JPL, for NASA's Solar Sail Spaceflight Simulation Software (SS). The aspect discussed in an experimental approach to modeling full six-degree-of-freedom kinetic motion of a solar sail in a trajectory propagator. Early results from implementing this approach in a new trajectory propagation tool are given.

  13. World Ships: The Solar-Photon Sail Option

    NASA Astrophysics Data System (ADS)

    Matloff, G. L.

    The World Ship, a spacecraft large enough to simulate a small-scale terrestrial internal environment, may be the best feasible option to transfer members of a technological civilization between neighboring stars. Because of the projected size of these spacecraft, journey durations of ~1,000 years seem likely. One of the propulsion options for World Ships is the hyper-thin, likely space-manufactured solar-photon sail, unfurled as close to the migrating civilization's home star as possible. Because the sail and associated structure can be wound around the habitat while not in use, it represents the only known ultimately feasible interstellar propulsion system that can be applied for en route galactic-cosmic ray shielding as well as acceleration/ deceleration. This paper reviews the three suggested sail configurations that can be applied to world ship propulsion: parachute, hollow-body and hoop sails. Possible existing and advanced sail and structure materials and the predicted effects on the sail of the near-Sun space environment are reviewed. Consideration of solar-photon-sail World Ships also affects SETI (the Search for Extraterrestrial Intelligence). Can we detect such craft in flight? When in a star's lifetime is migration using such craft likely? What classes of stars are good candidates for solar-sail World-Ship searches?

  14. Solar Sail Trajectories for Solar Polar and Heliopause Missions

    NASA Technical Reports Server (NTRS)

    Sauer, Carl G., Jr.

    2000-01-01

    Over the last several years, interest in a more vigorous space exploration program has renewed interest in the use of solar sails for the more demanding space missions. Solar sail is eminently suited for some of the higher energy missions since no fuel is consumed and the only criteria is that of the total time required to perform a particular mission. Although solar sail missions to planets and small bodies have been examined previously, and reported in the literature' classes of space missions with no well defined target body have received little attention. These Space Physics missions include some with extremely high energy requirements. Not only are these missions difficult, if not impractical, to accomplish with conventional chemical propulsion spacecraft, but they are also difficult to perform in the near future using projected electric-propulsion systems. Solar sail trajectories for two of the high energy Space Physics missions, a Solar Polar mission and a Heliopause mission, are examined in this paper. The object of the Solar Polar mission is to place 'a payload into a short period orbit around the Sun at a 90 degree inclination to either the ecliptic plane or the equatorial plane of the sun. A forerunner for this type of mission was the Ulysses spacecraft which used a gravity assist of Jupiter to place the spacecraft into a 90 degree inclination orbit around the Sun with a perihelion distance of around .55 AU. The orbital period for the Ulysses mission was around 5 years however, and future Solar Polar missions require many observational passes over the pole of the Sun each year thus implying a significantly shorter orbit period than that for Ulysses.

  15. Chasing a Comet with a Solar Sail

    NASA Technical Reports Server (NTRS)

    Stough, Robert W.; Heaton, Andrew F.; Whorton, Mark S.

    2008-01-01

    Solar sail propulsion systems enable a wide range of missions that require constant thrust or high delta-V over long mission times. One particularly challenging mission type is a comet rendezvous mission. This paper presents optimal low-thrust trajectory designs for a range of sailcraft performance metrics and mission transit times that enables a comet rendezvous mission. These optimal trajectory results provide a trade space which can be parameterized in terms of mission duration and sailcraft performance parameters such that a design space for a small satellite comet chaser mission is identified. These results show that a feasible space exists for a small satellite to perform a comet chaser mission in a reasonable mission time.

  16. Solar sail elastic displacement effects on interplanetary trajectories

    NASA Astrophysics Data System (ADS)

    Ingrassia, T.; Faccin, V.; Bolle, A.; Circi, C.; Sgubini, S.

    2013-02-01

    Space agencies are paying greater attention to solar sail technologies and missions. Actually, one of the most demanding issues when considering solar sailing is to assess the sail deformation as well as the following trajectory modifications. The main purpose of this paper is to show the order of accuracy that can be reached when coupling structural and dynamical behavior of a solar sail. Based on the application of the Finite Element Method, the deformations affecting the large structure of the sail, up to the second order of accuracy, are estimated, together with the real-time updated thrust vector according to such deformations. The new thrust vector, evaluated for an Earth-Venus mission, allows one to find a more realistic sailcraft trajectory. The results obtained show a change in the thrust's magnitude with a not negligible variation of the sailcraft trajectory with respect to the undeformed case. Another issue deserving particular attention concerns solar sail deployment. Both structural and dynamical behavior affecting a solar sail's performance will be analyzed even in the event of partial deployment. The results obtained show the importance of the right sizing of the attitude control, which may not be able to compensate such a failure and what strategies could be used to save the mission including the need for a new mission analysis.

  17. An Update to the NASA Reference Solar Sail Thrust Model

    NASA Technical Reports Server (NTRS)

    Heaton, Andrew F.; Artusio-Glimpse, Alexandra B.

    2015-01-01

    An optical model of solar sail material originally derived at JPL in 1978 has since served as the de facto standard for NASA and other solar sail researchers. The optical model includes terms for specular and diffuse reflection, thermal emission, and non-Lambertian diffuse reflection. The standard coefficients for these terms are based on tests of 2.5 micrometer Kapton sail material coated with 100 nm of aluminum on the front side and chromium on the back side. The original derivation of these coefficients was documented in an internal JPL technical memorandum that is no longer available. Additionally more recent optical testing has taken place and different materials have been used or are under consideration by various researchers for solar sails. Here, where possible, we re-derive the optical coefficients from the 1978 model and update them to accommodate newer test results and sail material. The source of the commonly used value for the front side non-Lambertian coefficient is not clear, so we investigate that coefficient in detail. Although this research is primarily designed to support the upcoming NASA NEA Scout and Lunar Flashlight solar sail missions, the results are also of interest to the wider solar sail community.

  18. Solar and Drag Sail Propulsion: From Theory to Mission Implementation

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Alhorn, Dean; Boudreaux, Mark; Casas, Joe; Stetson, Doug; Young, Roy

    2014-01-01

    Solar and drag sail technology is entering the mainstream for space propulsion applications within NASA and around the world. Solar sails derive propulsion by reflecting sunlight from a large, mirror- like sail made of a lightweight, reflective material. The continuous sunlight pressure provides efficient primary propulsion, without the expenditure of propellant or any other consumable, allowing for very high V maneuvers and long-duration deep space exploration. Drag sails increase the aerodynamic drag on Low Earth Orbit (LEO) spacecraft, providing a lightweight and relatively inexpensive approach for end-of-life deorbit and reentry. Since NASA began investing in the technology in the late 1990's, significant progress has been made toward their demonstration and implementation in space. NASA's Marshall Space Flight Center (MSFC) managed the development and testing of two different 20-m solar sail systems and rigorously tested them under simulated space conditions in the Glenn Research Center's Space Power Facility at Plum Brook Station, Ohio. One of these systems, developed by L'Garde, Inc., is planned for flight in 2015. Called Sunjammer, the 38m sailcraft will unfurl in deep space and demonstrate solar sail propulsion and navigation as it flies to Earth-Sun L1. In the Flight Center (MSFC) managed the development and testing of two different 20-m solar sail systems and rigorously tested them under simulated space conditions in the Glenn Research Center's Space Power Facility at Plum Brook Station, Ohio. One of these systems, developed by L'Garde, Inc., is planned for flight in 2015. Called Sunjammer, the 38m sailcraft will unfurl in deep space and demonstrate solar sail propulsion and navigation as it flies to Earth-Sun L1. In the interim, NASA MSFC funded the NanoSail-D, a subscale drag sail system designed for small spacecraft applications. The NanoSail-D flew aboard the Fast Affordable Science and Technology SATellite (FASTSAT) in 2010, also developed by MSFC

  19. NEA Scout Solar Sail: Half-scale Fold Time Lapse

    NASA Video Gallery

    In this time lapse, the Near-Earth Asteroid Scout (NEA Scout) CubeSat team rolls a half-scale prototype of the small satellite's solar sail in preparation for a deployment test. During its mission,...

  20. Space exploration with a solar sail coated by materials that undergo thermal desorption

    NASA Astrophysics Data System (ADS)

    Kezerashvili, Roman Ya.

    2015-12-01

    For extrasolar space exploration it is suggested to use space environmental effects such as solar radiation heating to accelerate a solar sail coated by materials that undergo thermal desorption at a particular temperature. The developed approach allows the perihelion of the solar sail orbits to be determined based on the temperature requirement for the solar sail materials. Our study shows that the temperature of a solar sail increases as r - 2 / 5 when the heliocentric distance r decreases. The proposed sail has two coats of the materials that undergo desorption at different solar sail temperatures depending on the heliocentric distance. The first desorption occurs at the Earth orbit and provides the thrust needed to propel the solar sail toward the Sun. When the solar sail approaches the Sun, its temperature increases, and the second coat undergoes desorption at the perihelion of the heliocentric escape orbit. This provides a second thrust and boosts the solar sail to its escape velocity.

  1. Consideration of puncture by micrometeors in the equations of motion of a solar-sail vehicle

    NASA Astrophysics Data System (ADS)

    Poliakhova, E. N.; Sharifkulova, G. A.; Shuvalov, V. V.

    The problem of the motion of a degrading solar sail is analyzed with allowance for the irreversible changes in the solar sail material (a metallized polymer film), including both erosion of the sail surface and puncture of the sail by micrometeors. The minimum mass and diameter of particles capable of puncturing the sail are estimated as a function of sail density, relative collision velocity, sail thickness, and its strength characteristic. The contribution of erosion due to collisions with micrometeor particles to the degradation of the sail is also estimated.

  2. The dynamics and control of the CubeSail mission: A solar sailing demonstration

    NASA Astrophysics Data System (ADS)

    Pukniel, Andrew; Coverstone, Victoria; Burton, Rodney; Carroll, David

    2011-12-01

    The CubeSail mission is a low-cost demonstration of the UltraSail solar sailing concept ( Burton et al., 2005; Botter et al., 2006; Hargens-Rysanek, 2006; Pukniel, 2009), using two near-identical CubeSat satellites to deploy a 260 m-long, 20 m 2 reflecting film. The two satellites are launched as a unit, detumbled, and separated, with the film unwinding symmetrically from motorized reels. The conformity to the CubeSat specification allows for reduction in launch costs as a secondary payload and utilization of the University of Illinois-developed spacecraft bus. The CubeSail demonstration is the first in a series of increasingly-complex missions aimed at validating several spacecraft subsystems, including attitude determination and control, the separation release unit, reel-based film deployment, as well as the dynamical behavior of the sail and on-orbit solar propulsion. The presented work describes dynamical behavior and control methods used during three main phases of the mission. The three phases include initial detumbling and stabilization using magnetic torque actuators, gravity-gradient-based deployment of the film, and steady-state film deformations in low Earth orbit in the presence of external forces of solar radiation pressure, aerodynamic drag, and gravity-gradient.

  3. Attitude control requirements for various solar sail missions

    NASA Technical Reports Server (NTRS)

    Williams, Trevor

    1990-01-01

    The differences are summarized between the attitude control requirements for various types of proposed solar sail missions (Earth orbiting; heliocentric; asteroid rendezvous). In particular, it is pointed out that the most demanding type of mission is the Earth orbiting one, with the solar orbit case quite benign and asteroid station keeping only slightly more difficult. It is then shown, using numerical results derived for the British Solar Sail Group Earth orbiting design, that the disturbance torques acting on a realistic sail can completely dominate the torques required for nominal maneuvering of an 'ideal' sail. This is obviously an important consideration when sizing control actuators; not so obvious is the fact that it makes the standard rotating vane actuator unsatisfactory in practice. The reason for this is given, and a set of new actuators described which avoids the difficulty.

  4. Moving an asteroid with electric solar wind sail

    NASA Astrophysics Data System (ADS)

    Merikallio, S.; Janhunen, P.

    2010-12-01

    The electric solar wind sail (E-Sail) is a new propulsion method for interplanetary travel which was invented in 2006 and is currently under development. The E-Sail uses charged tethers to extract momentum from the solar wind particles to obtain propulsive thrust. According to current estimates, the E-Sail is 2-3 orders of magnitude better than traditional propulsion methods (chemical rockets and ion engines) in terms of produced lifetime-integrated impulse per propulsion system mass. Here we analyze the problem of using the E-Sail for directly deflecting an Earth-threatening asteroid. The problem then culminates into how to attach the E-Sail device to the asteroid. We assess alternative attachment strategies, namely straightforward direct towing with a cable and the gravity tractor method which works for a wider variety of situations. We also consider possible techniques to scale up the E-Sail force beyond the baseline one Newton level to deal with more imminent or larger asteroid or cometary threats. As a baseline case we consider an asteroid of effective diameter of 140 m and mass of 3 million tons, which can be deflected with a baseline 1 N E-Sail within 10 years. With a 5 N E-Sail the deflection could be achieved in 5 years. Once developed, the E-Sail would appear to provide a safe and reasonably low-cost way of deflecting dangerous asteroids and other heavenly bodies in cases where the collision threat becomes known several years in advance.

  5. Invited Article: Electric solar wind sail: Toward test missions

    NASA Astrophysics Data System (ADS)

    Janhunen, P.; Toivanen, P. K.; Polkko, J.; Merikallio, S.; Salminen, P.; Haeggström, E.; Seppänen, H.; Kurppa, R.; Ukkonen, J.; Kiprich, S.; Thornell, G.; Kratz, H.; Richter, L.; Krömer, O.; Rosta, R.; Noorma, M.; Envall, J.; Lätt, S.; Mengali, G.; Quarta, A. A.; Koivisto, H.; Tarvainen, O.; Kalvas, T.; Kauppinen, J.; Nuottajärvi, A.; Obraztsov, A.

    2010-11-01

    The electric solar wind sail (E-sail) is a space propulsion concept that uses the natural solar wind dynamic pressure for producing spacecraft thrust. In its baseline form, the E-sail consists of a number of long, thin, conducting, and centrifugally stretched tethers, which are kept in a high positive potential by an onboard electron gun. The concept gains its efficiency from the fact that the effective sail area, i.e., the potential structure of the tethers, can be millions of times larger than the physical area of the thin tethers wires, which offsets the fact that the dynamic pressure of the solar wind is very weak. Indeed, according to the most recent published estimates, an E-sail of 1 N thrust and 100 kg mass could be built in the rather near future, providing a revolutionary level of propulsive performance (specific acceleration) for travel in the solar system. Here we give a review of the ongoing technical development work of the E-sail, covering tether construction, overall mechanical design alternatives, guidance and navigation strategies, and dynamical and orbital simulations.

  6. Invited article: Electric solar wind sail: toward test missions.

    PubMed

    Janhunen, P; Toivanen, P K; Polkko, J; Merikallio, S; Salminen, P; Haeggström, E; Seppänen, H; Kurppa, R; Ukkonen, J; Kiprich, S; Thornell, G; Kratz, H; Richter, L; Krömer, O; Rosta, R; Noorma, M; Envall, J; Lätt, S; Mengali, G; Quarta, A A; Koivisto, H; Tarvainen, O; Kalvas, T; Kauppinen, J; Nuottajärvi, A; Obraztsov, A

    2010-11-01

    The electric solar wind sail (E-sail) is a space propulsion concept that uses the natural solar wind dynamic pressure for producing spacecraft thrust. In its baseline form, the E-sail consists of a number of long, thin, conducting, and centrifugally stretched tethers, which are kept in a high positive potential by an onboard electron gun. The concept gains its efficiency from the fact that the effective sail area, i.e., the potential structure of the tethers, can be millions of times larger than the physical area of the thin tethers wires, which offsets the fact that the dynamic pressure of the solar wind is very weak. Indeed, according to the most recent published estimates, an E-sail of 1 N thrust and 100 kg mass could be built in the rather near future, providing a revolutionary level of propulsive performance (specific acceleration) for travel in the solar system. Here we give a review of the ongoing technical development work of the E-sail, covering tether construction, overall mechanical design alternatives, guidance and navigation strategies, and dynamical and orbital simulations. PMID:21133454

  7. Solar Sail Propulsion: An Enabling Technology for Fundamental Physics Missions

    NASA Astrophysics Data System (ADS)

    Dachwald, Bernd; Seboldt, Wolfgang; Lämmerzahl, Claus

    Solar sails enable a wide range of high-energy missions, many of which are difficult or even impossible to accomplish with any other type of conventional propulsion system. They are also an enabling propulsion technology for two types of deep-space missions that are very favorable for testing current gravitational theories and the large-scale gravitational field of the solar system: the first type comprises missions that go very close to the Sun (<8 solar radii) and the second one comprises missions that go fast very far away from the Sun (~200AU). Being propelled solely by the freely available solar radiation pressure, solar sails do not consume any propellant. Therefore, their capability to gain (or reduce) orbital energy is theoretically unlimited and practically only limited by their lifetime in the space environment and their distance from the Sun (because the solar radiation pressure decreases with the square of solar distance). Nevertheless, solar sails make also missions that go far away from the Sun feasible because they can gain a large amount of orbital energy by first making one or more close solar approaches that turn the trajectory hyperbolic. For both mission types, the temperature limit of the sail film is a critical issue. In this chapter, we briefly review the physics and the current technological status of solar sails, and then present mission outlines and trade-offs for both mission types. Thereby, we will show that even near- or medium-term solar sails with a relatively moderate performance enable these kinds of missions.

  8. Strong thin membrane structure. [solar sails

    NASA Technical Reports Server (NTRS)

    Frazer, R. E. (Inventor)

    1979-01-01

    A continuous process is described for producing strong lightweight structures for use as solar sails for spacecraft propulsion by radiation pressure. A thin reflective coating, such as aluminum, is applied to a rotating cylinder. A nylon mesh, applied over the aluminum coating, is then coated with a polymerizing material such as a para-xylylene monomer gas to polymerize as a film bound to the mesh and the aluminum. An emissivity increasing material such as chromium or silicon monoxide is applied to the polymer film to disperse such material colloidally into the growing polymer film, or to the final polymer film. The resulting membrane structure is then removed from the cylinder. Alternately, the membrane structure can be formed by etching a substrate in the form of an organic film such as a polymide, or a metal foil, to remove material from the substrate and reduce its thickness. A thin reflective coating (aluminum) is applied on one side of the substrate, and an emissivity increasing coating is applied on the reverse side of the substrate.

  9. Demonstration of a 10-m Solar Sail System

    NASA Technical Reports Server (NTRS)

    Murphy, David M.; Macy, Brian D.; Gaspar, James L.

    2004-01-01

    The NASA In-Space Propulsion (ISP) program has been sponsoring system design development and hardware demonstration activities of solar sail technology over the past 16 months. Efforts to validate by test a moderate-scale (10-m) 1/4 symmetry ground demonstration sail system are nearly complete. Results of testing and analytical model validation of component and assembly functional, strength, stiffness, shape, and dynamic behavior are discussed.

  10. Hybrids of Solar Sail, Solar Electric, and Solar Thermal Propulsion for Solar-System Exploration

    NASA Technical Reports Server (NTRS)

    Wilcox, Brian H.

    2012-01-01

    Solar sails have long been known to be an attractive method of propulsion in the inner solar system if the areal density of the overall spacecraft (S/C) could be reduced to approx.10 g/sq m. It has also long been recognized that the figure (precise shape) of useful solar sails needs to be reasonably good, so that the reflected light goes mostly in the desired direction. If one could make large reflective surfaces with reasonable figure at an areal density of approx.10 g/sq m, then several other attractive options emerge. One is to use such sails as solar concentrators for solar-electric propulsion. Current flight solar arrays have a specific output of approx. 100W/kg at 1 Astronomical Unit (AU) from the sun, and near-term advances promise to significantly increase this figure. A S/C with an areal density of 10 g/sq m could accelerate up to 29 km/s per year as a solar sail at 1 AU. Using the same sail as a concentrator at 30 AU, the same spacecraft could have up to approx. 45 W of electric power per kg of total S/C mass available for electric propulsion (EP). With an EP system that is 50% power-efficient, exhausting 10% of the initial S/C mass per year as propellant, the exhaust velocity is approx. 119 km/s and the acceleration is approx. 12 km/s per year. This hybrid thus opens attractive options for missions to the outer solar system, including sample-return missions. If solar-thermal propulsion were perfected, it would offer an attractive intermediate between solar sailing in the inner solar system and solar electric propulsion for the outer solar system. In the example above, both the solar sail and solar electric systems don't have a specific impulse that is near-optimal for the mission. Solar thermal propulsion, with an exhaust velocity of the order of 10 km/s, is better matched to many solar system exploration missions. This paper derives the basic relationships between these three propulsion options and gives examples of missions that might be enabled by

  11. Phobos/Deimos Sample Return via Solar Sail

    NASA Technical Reports Server (NTRS)

    Matloff, Gregory L.; Taylor, Travis; Powell, Conley; Moton, Tryshanda

    2004-01-01

    Abstract A sample-return mission to the martian satellites using a contemporary solar sail for all post-Earth-escape propulsion is proposed. The 0.015 kg/sq m areal mass-thickness sail unfurls after launch and injection onto a Mars-bound Hohmann-transfer ellipse. Structure and pay!oad increase spacecraft areal mass thickness to 0.028 kg/sq m. During Mars-encounter, the sail functions parachute-like in Mars s outer atmosphere to accomplish aerocapture. On-board thrusters or the sail maneuver the spacecraft into an orbit with periapsis near Mars and apoapsis near Phobos. The orbit is circularized for Phobos-rendezvous; surface samples are collected. The sail then raises the orbit for Deimos-rendezvous and sample collection. The sail next places the spacecraft on an Earth-bound Hohmann-transfer ellipse. During Earth-encounter, the sail accomplishes Earth-aerocapture or partially decelerates the sample container for entry into Earth s atmosphere. Mission mass budget is about 218 grams and; mission duration is <5 years.

  12. Photon Acceleration Model of Flexible Spinning Solar Sail

    NASA Astrophysics Data System (ADS)

    Mimasu, Yuya; Kitajima, Akifumi; Yamaguchi, Tomohiro; Funase, Ryu; Y. Morimoto, Mutsuko; Sawada, Hirotaka; Takeuchi, Hiroshi; Mori, Osamu; Tsuda, Yuichi; Kawaguchi, Jun'ichiro

    The solar sailing spacecraft is one of the promising propulsion systems for the future deep space exploration mission. Japan Aerospace Exploration Agency (JAXA) has been studying the spin solar sail spacecraft which has a squared-shape type solar sail. One of the most significant objective to control the satellite orbit of the spacecraft is to estimate the thrust force induced by the photon, namely to establish the acceleration model before the launch. In a view point to use this model in orbit, the calibration of the acceleration model and evaluation of the dynamics on orbit are also important issue. This paper presents the way to construct the acceleration model of the Solar Radiation Pressure (SRP) on ground, and the calibration and evaluation strategy for this model by using the on-orbit data.

  13. Solar Sail Application to Comet Nucleus Sample Return

    NASA Technical Reports Server (NTRS)

    Taylor, Travis S.; Moton, Tryshanda T.; Robinson, Don; Anding, R. Charles; Matloff, Gregory L.; Garbe, Gregory; Montgomery, Edward

    2003-01-01

    Many comets have perihelions at distances within 1.0 Astronomical Unit (AU) from the sun. These comets typically are inclined out of the ecliptic. We propose that a solar sail spacecraft could be used to increase the inclination of the orbit to match that of these 1.0 AU comets. The solar sail spacecraft would match the orbit velocity for a short period of time, which would be long enough for a container to be injected into the comet's nucleus. The container would be extended from a long durable tether so that the solar sail would not be required to enter into the potentially degrading environment of the comet s atmosphere. Once the container has been filled with sample material, the tether is retracted. The solar sail would then lower its inclination and fly back to Earth for the sample return. In this paper, we describe the selection of cometary targets, the mission design, and the solar sailcraft design suitable for sail-comet rendezvous as well as possible rendezvous scenarios.

  14. Control of Lagrange point orbits using solar sail propulsion

    NASA Astrophysics Data System (ADS)

    Bookless, John; McInnes, Colin

    2008-01-01

    Several missions have utilised halo orbits around the L1 and L2 Lagrange points of the Earth-Sun system. Due to the instability of these orbits, station-keeping techniques are required to prevent escape after orbit insertion. This paper considers using solar sail propulsion to provide station-keeping at quasi-periodic orbits around L1 and L2. Stable manifolds will be identified which provide near-Earth insertion to a quasi-periodic trajectory around the libration point. The possible control techniques investigated include solar sail area variation and solar sail pitch and yaw angle variation. Hill's equations are used to model the dynamics of the problem and optimal control laws are developed to minimise the control requirements. The constant thrust available using solar sails can be used to generate artificial libration points Sunwards of L1 or Earthwards of L2. A possible mission to position a science payload Sunward of L1 will be investigated. After insertion to a halo orbit at L1, gradual solar sail deployment can be performed to spiral Sunwards along the Sun-Earth axis. Insertion ΔV requirements and area variation control requirements will be examined. This mission could provide advance warning of Earthbound coronal mass ejections (CMEs) responsible for magnetic storms.

  15. Combination Solar Sail and Electrodynamic Tether Propulsion System

    NASA Technical Reports Server (NTRS)

    Johnson, Charles L. (Inventor); Matloff, Gregory L. (Inventor)

    2003-01-01

    A propulsion system for a spacecraft includes a solar sail system and an electrodynamic tether system is presented. The solar sail system is used to generate propulsion to propel the spacecraft through space using solar photons and the electrodynamic tether system is used to generate propulsion to steer the spacecraft into orbit and to perform orbital maneuvers around a planet using the planet's magnetic field. The electrodynamic tether system can also be used to generate power for the spacecraft using the planet's magnetic field.

  16. Recent Progress in Heliogyro Solar Sail Structural Dynamics

    NASA Technical Reports Server (NTRS)

    Wilkie, William K.; Warren, Jerry E.; Horta, Lucas G.; Juang, Jer-Nan; Gibbs, Samuel C.; Dowell, E.; Guerrant, Daniel; Lawrence Dale

    2014-01-01

    Results from recent National Aeronautics and Space Administration (NASA) research on the structural dynamics and control characteristics of heliogyro solar sails are summarized. Specific areas under investigation include coupled nonlinear finite element analysis of heliogyro membrane blade with solar radiation pressure effects, system identification of spinning membrane structures, solarelastic stability analysis of heliogyro solar sails, including stability during blade deployment, and results from small-scale in vacuo dynamics experiments with spinning high-aspect ratio membranes. A low-cost, rideshare payload heliogyro technology demonstration mission concept, used as a mission context for these heliogyro structural dynamics and solarelasticity investigations, is also described.

  17. Safety criteria for flying E-sail through solar eclipse

    NASA Astrophysics Data System (ADS)

    Janhunen, Pekka; Toivanen, Petri

    2015-09-01

    The electric solar wind sail (E-sail) propellantless propulsion device uses long, charged metallic tethers to tap momentum from the solar wind to produce spacecraft propulsion. If flying through planetary or moon eclipse, the long E-sail tethers can undergo significant thermal contraction and expansion. Rapid shortening of the tether increases its tension due to inertia of the tether and a Remote Unit that is located on the tether tip (a Remote Unit is part of typical E-sail designs). We analyse by numerical simulation the conditions under which eclipse induced stresses are safe for E-sail tethers. We calculate the closest safe approach distances for Earth, Moon, Venus, Mars, Jupiter, Ceres and an exemplary 300 km main belt asteroid Interamnia for circular, parabolic and hyperbolic orbits. We find that any kind of eclipsing is safe beyond approximately 2.5 au distance, but for terrestrial planets safety depends on the parameters of the orbit. For example, for Mars the safe distance with 20 km E-sail tether lies between Phobos and Deimos orbits.

  18. Characterization of Space Environmental Effects on Candidate Solar Sail Material

    NASA Technical Reports Server (NTRS)

    Edwards, David; Hubbs, Whitney; Stanaland, Tesia; Altstatt, Richard

    2002-01-01

    The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) is concentrating research into the utilization of photonic materials for spacecraft propulsion. Spacecraft propulsion, using photonic materials, will be achieved using a solar sail. A sail operates on the principle that photons, originating from the sun, impart pressure and provide a source of spacecraft propulsion. The pressure can be increased, by a factor of two if the sun-facing surface is perfectly reflective. Solar sails are generally composed of a highly reflective metallic front layer, a thin polymeric substrate, and occasionally a highly emissive back surface. The Space Environmental Effects Team at MSFC is actively characterizing candidate solar sail materials to evaluate the thermo-optical and mechanical properties after exposure to a simulated Geosynchronous Transfer Orbit (GTO) radiation environment. The technique of radiation dose verses material depth profiling was used to determine the orbital equivalent exposure doses. The solar sail exposure procedures and results of the material characterization will be discussed.

  19. Design and Development of NEA Scout Solar Sail Deployer Mechanism

    NASA Technical Reports Server (NTRS)

    Sobey, Alexander R.; Lockett, Tiffany Russell

    2016-01-01

    The 6U (approximately10cm x 20cm x 30cm) cubesat Near Earth Asteroid (NEA) Scout, projected for launch in September 2018 aboard the maiden voyage of the Space Launch System (SLS), will utilize a solar sail as its main method of propulsion throughout its approximately 3 year mission to a near earth asteroid. Due to the extreme volume constraints levied onto the mission, an acutely compact solar sail deployment mechanism has been designed to meet the volume and mass constraints, as well as provide enough propulsive solar sail area and quality in order to achieve mission success. The design of such a compact system required the development of approximately half a dozen prototypes in order to identify unforeseen problems and advance solutions. Though finite element analysis was performed during this process in an attempt to quantify forces present within the mechanism during deployment, both the boom and the sail materials do not lend themselves to achieving high-confidence results. This paper focuses on the obstacles of developing a solar sail deployment mechanism for such an application and the lessons learned from a thorough development process. The lessons presented here will have significant applications beyond the NEA Scout mission, such as the development of other deployable boom mechanisms and uses for gossamer-thin films in space.

  20. Equilibria near asteroids for solar sails with reflection control devices

    NASA Astrophysics Data System (ADS)

    Gong, Shengping; Li, Junfeng

    2015-02-01

    Solar sails are well-suited for long-term, multiple-asteroid missions. The dynamics of solar sails near an asteroid have not yet been studied in detail. In this paper, out-of-plane artificial equilibria in a Sun-asteroid rotating frame and hovering points in a body-fixed rotating frame are studied (using a solar sail equipped with reflection control devices). First, the dynamics and the stability of out-of-plane artificial equilibria are studied as an elliptical restricted three body problem. Next, the body-fixed hovering problem is discussed as a two-body problem. Hovering flight is only possible for certain values of the latitude of the asteroid's orbit. In addition, the feasible range of latitudes is determined for each landmark on the asteroid's surface. The influence of the sail lightness number on the feasible range is also illustrated. Several special families of hovering points are discussed. These points include points above the equator and poles and points with an altitude equal to the radius of the synchronous orbit. In both of these types of problems, the solar sail (equipped with reflection control devices) can equilibrate over a large range of locations.

  1. The Role of Structural Models in the Solar Sail Flight Validation Process

    NASA Technical Reports Server (NTRS)

    Johnston, John D.

    2004-01-01

    NASA is currently soliciting proposals via the New Millennium Program ST-9 opportunity for a potential Solar Sail Flight Validation (SSFV) experiment to develop and operate in space a deployable solar sail that can be steered and provides measurable acceleration. The approach planned for this experiment is to test and validate models and processes for solar sail design, fabrication, deployment, and flight. These models and processes would then be used to design, fabricate, and operate scaleable solar sails for future space science missions. There are six validation objectives planned for the ST9 SSFV experiment: 1) Validate solar sail design tools and fabrication methods; 2) Validate controlled deployment; 3) Validate in space structural characteristics (focus of poster); 4) Validate solar sail attitude control; 5) Validate solar sail thrust performance; 6) Characterize the sail's electromagnetic interaction with the space environment. This poster presents a top-level assessment of the role of structural models in the validation process for in-space structural characteristics.

  2. Flexible Dynamics and Attitude Control of a Square Solar Sail

    NASA Astrophysics Data System (ADS)

    Choi, Mirue

    This thesis presents a comprehensive analysis of attitude and structural dynamics of a square solar sail. In particular, this research examines the use of corner-attached reflective vanes to control the attitude of the spacecraft. An introduction to known solar sail designs is given, then the mathematics involved in calculating solar radiation pressure forces are presented. A detailed derivation and implementation of the unconstrained nonlinear flexible structural dynamics with Finite Element Method (FEM) models are explored, with several sample simulations of published large deflection experiments used as verification measures. To simulate the inability of a thin membrane to resist compression, the sail membrane elements are augmented with a method that approximates the wrinkling and the slacking dynamics, which is followed by a simulation of another well-known experiment as a verification measure. Once the structural dynamics are established, the usage of the tip vanes is explored. Specifically, a control allocation problem formed by having two degrees of freedom for each tip vane is defined and an efficient solution to this problem is presented, allowing desired control torques to be converted to appropriate vane angles. A randomized testing mechanism is implemented to show the efficacy of this algorithm. The sail shadowing problem is explored as well, where a component of the spacecraft casts shadow upon the sail and prevents solar radiation pressure force from being produced. A method to calculate the region of shadow is presented, and two different shadowing examples are examined --- due to the spacecraft bus, and due to the sail itself. Combining all of the above, an attitude control simulation of the sail model is presented. A simple PD controller combined with the control allocation scheme is used to provide the control torque for the sail, with which the spacecraft must orient towards a number of pre-specified attitude targets. Several attitude

  3. An Overview of Solar Sail Propulsion within NASA

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Swartzlander, Grover A.; Artusio-Glimpse, Alexandra

    2013-01-01

    Solar Sail Propulsion (SSP) is a high-priority new technology within The National Aeronautics and Space Administration (NASA), and several potential future space missions have been identified that will require SSP. Small and mid-sized technology demonstration missions using solar sails have flown or will soon fly in space. Multiple mission concept studies have been performed to determine the system level SSP requirements for their implementation and, subsequently, to drive the content of relevant technology programs. The status of SSP technology and potential future mission implementation within the United States (US) will be described.

  4. Solar Sail Roadmap Mission GN and C Challenges

    NASA Technical Reports Server (NTRS)

    Heaton, Andrew F.

    2005-01-01

    The NASA In-Space Propulsion program is funding development work for solar sails to enhance future scientific opportunities. Key to this effort are scientific solar sail roadmap missions identified by peer review. The two near-term missions of interest are L1 Diamond and Solar Polar Imager. Additionally, the New Millennium Program is sponsoring the Space Technology 9 (ST9) demonstration mission. Solar sails are one of five technologies competing for the ST9 flight demonstration. Two candidate solar sail missions have been identified for a potential ST9 flight. All the roadmap missions and candidate flight demonstration missions face various GN&C challenges. A variety of efforts are underway to address these challenges. These include control actuator design and testing, low thrust optimization studies, attitude control system design and modeling, control-structure interaction studies, trajectory control design, and solar radiation pressure model development. Here we survey the various efforts underway and identify a few of specific recent interest and focus.

  5. In-Vacuum Photogrammetry of a 10-Meter Solar Sail

    NASA Technical Reports Server (NTRS)

    Meyer, Chris G.; Jones, Thomas W.; Lunsford, Charles B.; Pappa, Richard S.

    2005-01-01

    In July 2004, a 10-meter solar sail structure developed by L Garde, Inc. was tested in vacuum at the NASA Glenn 30-meter Plum Brook Space Power Facility in Sandusky, Ohio. The three main objections of the test were to demonstrate unattended deployment from a stowed configuration, to measure the deployed shape of the sail at both ambient and cryogenic room temperatures, and to measure the deployed structural dynamic characteristics (vibration modes). This paper summarizes the work conducted to fulfill the second test objective. The deployed shape was measured photogrammetrically in vacuum conditions with four 2-megapixel digital video cameras contained in custom made pressurized canisters. The canisters included high-intensity LED ring lights to illuminate a grid of retroreflective targets distributed on the solar sail. The test results closely matched pre-test photogrammetry numerical simulations and compare well with ABAQUS finite-element model predictions.

  6. Fuel consumption for interplanetary missions of solar sailing

    NASA Astrophysics Data System (ADS)

    Gong, ShengPing; Li, JunFeng

    2014-03-01

    The orbits of solar sails can be changed by adjusting the sail's attitude through external control torques. The resulting momentum will be changed, either provided by a typical attitude control subsystem or by a propellantless device. This paper investigates the extra momentum input and fuel consumption for a typical attitude control subsystem. The minimum-time transfer trajectories are designed for two rendezvous missions using both indirect and direct methods, generating continuous and discrete attitude histories, respectively. The results show that the momentum variation is almost wholly due to the solar radiation pressure. The feasibility of using tip-mounted microthrusters for attitude control is evaluated. The results show that less than 0.1 kg of propellant are required for an interplanetary transfer mission when pulsed plasma thrusters with a specific impulse of 700 s and a thrust of 150 mN are mounted at the tip of a 20 m square solar sail. The fuel consumptions of two transfer missions indicate that a tip-mounted pulsed plasma thruster is a viable technique for the attitude control of a solar sail.

  7. Solar Sail Optimal Orbit Transfers to Synchronous Orbits

    NASA Technical Reports Server (NTRS)

    Powers, Robert B.; Coverstone, Victoria; Prussing, John E.; Lunney, Bryan C. (Technical Monitor)

    1999-01-01

    A constant outward radial thrust acceleration can be used to reduce the radius of a circular orbit of specified period. Heliocentric circular orbits are designed to match the orbital period of Earth or Mars for various radial thrust accelerations and are defined as synchronous orbits. Minimum-time solar sail orbit transfers to these synchronous heliocentric orbits are presented.

  8. Design and Development of NEA Scout Solar Sail Deployer Mechanism

    NASA Technical Reports Server (NTRS)

    Sobey, Alexander R.; Lockett, Tiffany Russell

    2016-01-01

    The 6U (approx.10 cm x 20 cm x 30 cm) cubesat Near Earth Asteroid (NEA) Scout1, projected for launch in September 2018 aboard the maiden voyage of the Space Launch System, will utilize a solar sail as its main method of propulsion throughout its approx.3-year mission to a Near Earth Asteroid. Due to the extreme volume constraints levied onto the mission, an acutely compact solar sail deployment mechanism has been designed to meet the volume and mass constraints, as well as provide enough propulsive solar sail area and quality in order to achieve mission success. The design of such a compact system required the development of approximately half a dozen prototypes in order to identify unforeseen problems, advance solutions, and build confidence in the final design product. This paper focuses on the obstacles of developing a solar sail deployment mechanism for such an application and the lessons learned from a thorough development process. The lessons presented will have significant applications beyond the NEA Scout mission, such as the development of other deployable boom mechanisms and uses for gossamer-thin films in space.

  9. Design and Development of NEA Scout Solar Sail Deployer Mechanism

    NASA Technical Reports Server (NTRS)

    Sobey, Alexander R.; Lockett, Tiffany Russell

    2016-01-01

    The 6U (approximately 10cm x 20cm x 30cm) cubesat Near Earth Asteroid (NEA) Scout1, projected for launch in September 2018 aboard the maiden voyage of the Space Launch System (SLS), will utilize a solar sail as its main method of propulsion throughout its approximately 3 year mission to a Near Earth Asteroid (NEA). Due to the extreme volume constraints levied onto the mission, an acutely compact solar sail deployment mechanism has been designed to meet the volume and mass constraints, as well as provide enough propulsive solar sail area and quality in order to achieve mission success. The design of such a compact system required the development of approximately half a dozen prototypes in order to identify unforeseen problems, advance solutions, and build confidence in the final design product. This paper focuses on the obstacles of developing a solar sail deployment mechanism for such an application and the lessons learned from a thorough development process. The lessons presented will have significant applications beyond the NEA Scout mission, such as the development of other deployable boom mechanisms and uses for gossamer-thin films in space.

  10. Solar Array Sails: Possible Space Plasma Environmental Effects

    NASA Technical Reports Server (NTRS)

    Mackey, Willie R.

    2005-01-01

    An examination of the interactions between proposed "solar sail" propulsion systems with photovoltaic energy generation capabilities and the space plasma environments. Major areas of interactions ere: Acting from high voltage arrays, ram and wake effects, V and B current loops and EMI. Preliminary analysis indicates that arcing will be a major risk factor for voltages greater than 300V. Electron temperature enhancement in the wake will be produce noise that can be transmitted via the wake echo process. In addition, V and B induced potential will generate sheath voltages with potential tether like breakage effects in the thin film sails. Advocacy of further attention to these processes is emphasized so that plasma environmental mitigation will be instituted in photovoltaic sail design.

  11. Interplanetary Radiation and Internal Charging Environment Models for Solar Sails

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.; Altstatt, Richard L.; NeegaardParker, Linda

    2005-01-01

    A Solar Sail Radiation Environment (SSRE) model has been developed for defining charged particle environments over an energy range from 0.01 keV to 1 MeV for hydrogen ions, helium ions, and electrons. The SSRE model provides the free field charged particle environment required for characterizing energy deposition per unit mass, charge deposition, and dose rate dependent conductivity processes required to evaluate radiation dose and internal (bulk) charging processes in the solar sail membrane in interplanetary space. Solar wind and energetic particle measurements from instruments aboard the Ulysses spacecraft in a solar, near-polar orbit provide the particle data over a range of heliospheric latitudes used to derive the environment that can be used for radiation and charging environments for both high inclination 0.5 AU Solar Polar Imager mission and the 1.0 AU L1 solar missions. This paper describes the techniques used to model comprehensive electron, proton, and helium spectra over the range of particle energies of significance to energy and charge deposition in thin (less than 25 micrometers) solar sail materials.

  12. Solar sailing trajectory optimization with planetary gravity assist

    NASA Astrophysics Data System (ADS)

    Cai, XingShan; Li, JunFeng; Gong, ShengPing

    2015-01-01

    Significant propellant mass saving can be obtained with the use of complex multiple intermediate flyby maneuvers for conventional propulsion systems, and trip time also decreases for a portion of the proper solar sail missions. This paper discusses the performance of gravity assist (GA) in the time-optimal control problem of solar sailing with respect to sail lightness number and the energy difference between the initial and final orbit in the rendezvous problem in a two-body model, in which the GA is modeled as a substantial change in the velocity of the sailcraft at the GA time. In addition, this paper presents a method to solve the time-optimal problem of solar sailing with GA in a full ephemeris model, which introduces the third body's gravity in a dynamic equation. This study builds a set of inner constraints that can describe the GA process accurately. Finally, this study presents an example for evaluating the accuracy and rationality of the two-body model's simplification of GA by comparison with the full ephemeris model.

  13. Bringing an Effective Solar Sail Design Toward TRL 6

    NASA Technical Reports Server (NTRS)

    Lichodziejewski, David; West, John; Reinert, Rich; Belvin, Keith; Pappa, Richard; Derbes, Billy

    2003-01-01

    Solar sails reflect photons streaming from the sun and convert some of the energy into thrust. This thrust, though small, is continuous and acts for the life of the mission without the need for propellant ( I ) . Recent advances in sail materials and ultra-low mass structures have enabled a host of useful missions utilizing solar sail propulsion. The team of L Garde, Jet Propulsion Laboratories, Ball Aerospace, and Langley Research Center, under the direction of NASA, has been developing a solar sail configuration to address NASA s future space propulsion needs. Utilizing inflatably deployed and Sub Tg rigidized boom components, this 10,000 sq m sailcraft achieves an areal density of 14.1 g/sq m and a characteristic acceleration of 0.58 mm/s . The entire configuration released by the upper stage has a mass of 232.9 kg and requires just 1.7 d of volume in the booster. After deployment, 92.2 kg of non-flight required equipment is jettisoned resulting in a sailcraft mass, including payload and control system, of 140.7 kg. This document outlines the accomplishments of a Phase 1 effort to advance the technology readiness level (TRL) of the concept from 3 toward a TRL of 6. The Phase 1 effort, the first of three proposed phases, addressed the design of the solar sail, its application to several missions currently under review at NASA, and developed a ground tes plan to bring the technology toward a TRL of 6.

  14. Large Area Dust Detector onboard Solar Power Sail Spacecraft

    NASA Astrophysics Data System (ADS)

    Yano, Hajime

    JAXA is aiming to launch the solar power sail engineering demonstrator to the outer planet region of the solar system like Jupiter and the Jovian Trojan asteroids in 2010's. Its interplanetary cruise is a relevant and rare opportunity to monitor physical properties that may be varied by heliocentric distances continuously such as solar wind, solar magnetosphere and micrometeoroid flux. We have been developing the largest but still light-weight dust detector ever to be onboard deep space probes since 2000. PVDF films of a few to 10's of micron thickness are attached as a small part of the solar sail membrane to count and time hypervelocity impacts by micrometeoroids larger than micron size. The first spaceflight test of this dust detector in the order of 100 cm2 detection area was conducted onboard SSSAT (Solar Sail Satellite) as the M-V sub-payload launched to LEO in September 2006. The second opportunity of this series will be the 4- channel impact sensors onboard Kagayaki nano-satellite as an H-IIA piggyback to be launched in 2008. Actual interplanetary measurements can be achieved by the Small Solar Power Sail Demonstrator that will go inside the orbit of the Earth (1 AU) close to Venus around 2010. On this spacecraft, the 8-channel PVDF sensors of about 1 m2 detection area will be onboard to test this system in the interplanetary operation and to hopefully measure dust flux anisotropy in the trailing edge of the Earth, heliocentric flux variance inside 1 AU, and opportunistic detections of possible cometary dust trails and flux enhancement near Venus. The sensors filter electronic, thermal and vibration noises and record time, peak hold value, and relax duration of signals of micrometeoroid impacts. When the full-size solar power sail mission goes beyond 1 AU passing the main asteroid belt to 5 AU in 2010's, this dust detector system will be onboard in the order of several m2 active area. It will also compare its results with infrared observation of zodiacal

  15. Solar sail orbits at the Earth-Moon libration points

    NASA Astrophysics Data System (ADS)

    Simo, Jules; McInnes, Colin R.

    2009-12-01

    Solar sail technology offer new capabilities for the analysis and design of space missions. This new concept promises to be useful in overcoming the challenges of moving throughout the solar system. In this paper, novel families of highly non-Keplerian orbits for solar sail spacecraft at linear order are investigated in the Earth-Moon circular restricted three-body problem, where the third body is a solar sail. In particular, periodic orbits near the collinear libration points in the Earth-Moon system will be explored along with their applications. The dynamics are completely different from the Earth-Sun system in that the sun line direction constantly changes in the rotating frame but rotates once per synodic lunar month. Using an approximate, first-order analytical solution to the nonlinear nonautonomous ordinary differential equations, periodic orbits can be constructed that are displaced above the plane of the restricted three-body system. This new family of orbits have the property of ensuring visibility of both the lunar far-side and the equatorial regions of the Earth, and can enable new ways of performing lunar telecommunications.

  16. Staggering Inflation To Stabilize Attitude of a Solar Sail

    NASA Technical Reports Server (NTRS)

    Quadrelli, Marco; West, John

    2007-01-01

    A document presents computational-simulation studies of a concept for stabilizing the attitude of a spacecraft during deployment of such structures as a solar sail or other structures supported by inflatable booms. Specifically, the solar sail considered in this paper is a square sail with inflatable booms and attitude control vanes at the corners. The sail inflates from its stowed configuration into a square sail with four segments and four vanes at the tips. Basically, the concept is one of controlling the rates of inflation of the booms to utilize in mass-distribution properties to effect changes in the system s angular momentum. More specifically, what was studied were the effects of staggering inflation of each boom by holding it at constant length for specified intervals between intervals of increasing length until full length is reached. The studies included sensitivity analyses of effects of variations in mass properties, boom lengths, rates of increase in boom length, initial rates of rotation of the spacecraft, and several asymmetries that could arise during deployment. The studies led to the conclusion that the final attitude of the spacecraft could be modified by varying the parameters of staggered inflation. Computational studies also showed that by feeding back attitude and attitude-rate measurements so that corrective action is taken during the deployment, the final attitude can be maintained very closely to the initial attitude, thus mitigating the attitude changes incurred during deployment and caused by modeling errors. Moreover, it was found that by optimizing the ratio between the holding and length-increasing intervals in deployment of a boom, one could cause deployment to track a desired deployment profile to place the entire spacecraft in a desired attitude at the end of deployment.

  17. EMMI-Electric solar wind sail facilitated Manned Mars Initiative

    NASA Astrophysics Data System (ADS)

    Janhunen, Pekka; Merikallio, Sini; Paton, Mark

    2015-08-01

    The novel propellantless electric solar wind sail concept promises efficient low thrust transportation in the Solar System outside Earth's magnetosphere. Combined with asteroid mining to provide water and synthetic cryogenic rocket fuel in orbits of Earth and Mars, possibilities for affordable continuous manned presence on Mars open up. Orbital fuel and water enable reusable bidirectional Earth-Mars vehicles for continuous manned presence on Mars and allow smaller fuel fraction of spacecraft than what is achievable by traditional means. Water can also be used as radiation shielding of the manned compartment, thus reducing the launch mass further. In addition, the presence of fuel in the orbit of Mars provides the option for an all-propulsive landing, thus potentially eliminating issues of heavy heat shields and augmenting the capability of pinpoint landing. With this E-sail enabled scheme, the recurrent cost of continuous bidirectional traffic between Earth and Mars might ultimately approach the recurrent cost of running the International Space Station, ISS.

  18. Controlling Attitude of a Solar-Sail Spacecraft Using Vanes

    NASA Technical Reports Server (NTRS)

    Mettler, Edward; Acikmese, Ahmet; Ploen, Scott

    2006-01-01

    A paper discusses a concept for controlling the attitude and thrust vector of a three-axis stabilized Solar Sail spacecraft using only four single degree-of-freedom articulated spar-tip vanes. The vanes, at the corners of the sail, would be turned to commanded angles about the diagonals of the square sail. Commands would be generated by an adaptive controller that would track a given trajectory while rejecting effects of such disturbance torques as those attributable to offsets between the center of pressure on the sail and the center of mass. The controller would include a standard proportional + derivative part, a feedforward part, and a dynamic component that would act like a generalized integrator. The controller would globally track reference signals, and in the presence of such control-actuator constraints as saturation and delay, the controller would utilize strategies to cancel or reduce their effects. The control scheme would be embodied in a robust, nonlinear algorithm that would allocate torques among the vanes, always finding a stable solution arbitrarily close to the global optimum solution of the control effort allocation problem. The solution would include an acceptably small angle, slow limit-cycle oscillation of the vanes, while providing overall thrust vector pointing stability and performance.

  19. Solar sail attitude dynamics and coning control: On Developing Control Methods for Solar Sail Coning at Orbit Rate to Attain Desired Orbital Effects

    NASA Astrophysics Data System (ADS)

    Rizvi, Farheen

    In this thesis, a control method is developed for the solar sail normal vector to trace a desired circular coning trajectory at orbit rate. The coning trajectory is defined in the local vertical local horizontal (LVLH) frame and the coning occurs about an LVLH equilibrium sail attitude. Past research has shown that sail attitude equilibria exist in the LVLH frame under the influence of aerodynamic, gravity gradient and solar torques. Precession of the sail normal from these equilibria causes sail normal coning about that equilibrium attitude. If the coning happens at orbit rate, wide variety of orbital effects can be induced with minimum excitation of the sailcraft structure. This results in an inexpensive spacecraft with a longer duration mission as compared to other conventional efforts. A special case of analyzing circular cones (at orbit rate coning) revealed that new Sun-synchronous orbits were created and launch injection errors were overcome by employing the sail coning method. The control method herein minimizes the angular momentum error between the sail and desired angular momentum vectors at orbit rate. Since angular momentum is a function of sail normal, angular momentum error reduction raises hope in reducing the sail normal error between the sail normal and desired sail normal vector as well. The results show that even though the control method enables the sail angular momentum to track the desired angular momentum on the coning trajectory, the sail normal tracing can only occur about certain LVLH equilibrium points, for small cones and small initial condition angular position/velocity errors. The control method is robust for tracking the desired angular momentum at orbit rate, but not always for tracking the desired sail normal. The case where the sail normal does track the desired at orbit rate corresponds to tracing a 1° circular cone about an orbit lowering LVLH equilibrium point. Even though the control torques are on the order of 10-6 Nm

  20. The effect of environmental plasma interactions on the performance of the solar sail system

    NASA Technical Reports Server (NTRS)

    Douglas, M.; Laquey, R.; Deforest, S. E.

    1977-01-01

    Interaction between the solar sail and the natural plasma environment were examined for deleterious impacts upon the operation of the sail and its associated payload. Electrostatic charging of the sail in the solar wind and in near earth environment were examined. Deployment problems were studied. An analysis of electromechanical oscillations coupling the sail to the natural plasma was performed. As a result of these studies, it was concluded that none of these effects will have a significant negative impact upon the sail operation. The natural environment will be significantly perturbed and this will preclude measurements of electric and magnetic fields from an attached payload.

  1. The optimal control for the tethered system formed by an asteroid and a solar sail

    NASA Astrophysics Data System (ADS)

    Gao, Youtao; Wu, Jingyun

    2016-02-01

    This paper focuses on a method of changing the orbit of an asteroid by attaching a solar sail to the asteroid. First, the dynamic model of the tethered system is derived. Legendre pseudospectral method is then used to discretize the system, and the sequence of two quadratic programming is utilized to obtain the optimal control law. Simulation results show that the tethered solar sail can efficiently change the asteroid's orbit. Moreover, the problem of the tether twining around the asteroid caused by the relative orbit motion between the solar sail and the asteroid can be avoided. Finally, the effectiveness of altering an asteroid's orbit by different solar sails is analyzed. Simulation results show that when the area of the solar sail is 106 m2, the asteroid can be deflected at 1.227 × 108 m by the solar sail after about 20 years, which is better than the effect of a gravitational tractor.

  2. SOLAR SAIL PROPULSION SENSITIVITY TO MEMBRANE SHAPE AND OPTICAL PROPERTIES USING THE SOLAR VECTORING EVALUATION TOOL (SVET)

    NASA Technical Reports Server (NTRS)

    Ewing, Anthony

    2005-01-01

    Solar sail propulsive performance is dependent on sail membrane optical properties and on sail membrane shape. Assumptions of an ideal sail (flat, perfect reflector) can result in errors which can affect spacecraft control, trajectory analyses, and overall evaluation of solar sail performance. A MATLAB(R) program has been developed to generate sail shape point cloud files for two square-architecture solar sail designs. Simple parabolic profiles are assumed for sail shape under solar pressure loading. These files are then input into the Solar Vectoring Evaluation Tool (SVET) software to determine the propulsive force vector, center of pressure, and moments about the sail body axes as a function of sail shape and optical properties. Also, the impact of the center-line angle, due to non-perfect optical properties, is addressed since this constrains sail force vector cone angle and is often overlooked when assuming ideal-reflector membranes. Preliminary sensitivity analysis using these tools aids in determining the key geometric and optical parameters that drive solar sail propulsive performance.

  3. Attitude Control for a Solar-Sail Spacecraft

    NASA Technical Reports Server (NTRS)

    Mettler, Edward; Ploen, Scott

    2004-01-01

    A report discusses the attitude-control system of a proposed spacecraft that would derive at least part of its propulsion from a solar sail. The spacecraft would include a bus module containing three or more reaction wheels, a boom attached at one end to the bus module and attached at its other end to a two-degree-of-freedom (DOF) gimbal at the nominal center of mass of a sail module. Each DOF of the gimbal could be independently locked against rotation or allowed to rotate freely. By using the reaction wheels to rotate the bus when at least one gimbal DOF was in the free state, the center of mass (CM) of the spacecraft could be shifted relative to the center of pressure (CP) on the solar sail. The resulting offset between the CM and CP would result in a solar torque, which could be used to change the attitude of the spacecraft. The report discusses numerous aspects of the dynamics and kinematics of the spacecraft, along with the relationships between these aspects and the designs of such attitude-control- system components as sensors, motors, brakes, clutches, and gimbals.

  4. Attitude and Translation Control of a Solar Sail Vehicle

    NASA Technical Reports Server (NTRS)

    Singh, Gurkirpal

    2008-01-01

    A report discusses the ability to control the attitude and translation degrees-of-freedom of a solar sail vehicle by changing its center of gravity. A movement of the spacecraft s center of mass causes solar-pressure force to apply a torque to the vehicle. At the compact core of the solar-sail vehicle lies the spacecraft bus which is a large fraction of the total vehicle mass. In this concept, the bus is attached to the spacecraft by two single degree-of-freedom linear tracks. This allows relative movement of the bus in the sail plane. At the null position, the resulting solar pressure applies no torque to the vehicle. But any deviation of the bus from the null creates an offset between the spacecraft center of mass and center of solar radiation pressure, resulting in a solar-pressure torque on the vehicle which changes the vehicle attitude. Two of the three vehicle degrees of freedom can be actively controlled in this manner. The third, the roll about the sunline, requires a low-authority vane/propulsive subsystem. Translation control of the vehicle is achieved by directing the solar-pressure-induced force in the proper inertial direction. This requires attitude control. Attitude and translation degrees-of-freedom are therefore coupled. A guidance law is proposed, which allows the vehicle to stationkeep at an appropriate point on the inertially-rotating Sun-Earth line. Power requirements for moving the bus are minimal. Extensive software simulations have been performed to demonstrate the feasibility of this concept.

  5. Reduction of Martian Sample Return Mission Launch Mass with Solar Sail Propulsion

    NASA Technical Reports Server (NTRS)

    Russell, Tiffany E.; Heaton, Andy F.; Young, Roy; Baysinger, Mike; Schnell, Andrew R.

    2013-01-01

    Solar sails have the potential to provide mass and cost savings for spacecraft traveling within the innter solar system. Companies like L'Garde have demonstrated sail manufacturability and various i-space development methods. The purpose of this study was to evaluate a current Mars sample return architecture and to determine how cost and mass would be reduced by incorporating a solar sail propulsion system. The team validated the design proposed by L'Garde, and scaled the design based on a trajectory analysis. Using the solar sail design reduced the required mass, eliminating one of the three launches required in the original architecture.

  6. Reduction of Martian Sample Return Mission Launch Mass with Solar Sail Propulsion

    NASA Technical Reports Server (NTRS)

    Russell, Tiffany E.; Heaton, Andrew; Thomas, Scott; Thomas, Dan; Young, Roy; Baysinger, Mike; Capizzo, Pete; Fabisinski, Leo; Hornsby, Linda; Maples, Dauphne; Miernik, Janie

    2013-01-01

    Solar sails have the potential to provide mass and cost savings for spacecraft traveling within the inner solar system. Companies like L'Garde have demonstrated sail manufacturability and various in-space deployment methods. The purpose of this study was to evaluate a current Mars sample return architecture and to determine how cost and mass would be reduced by incorporating a solar sail propulsion system. The team validated the design proposed by L'Garde, and scaled the design based on a trajectory analysis. Using the solar sail design reduced the required mass, eliminating one of the three launches required in the original architecture.

  7. A Summary fo Solar Sail Technology Developments and Proposed Demonstration Missions

    NASA Technical Reports Server (NTRS)

    Garner, Charles; Diedrich, Benjamin; Leipold, Manfred

    1999-01-01

    NASA's drive to reduce mission costs and accept the risk of incorporating innovative, high payoff technologies into it's missions while simultaneously undertaking ever more difficult missions has sparked a greatly renewed interest in solar sails. From virtually no technology or flight mission studies activity three years ago solar sails are now included in NOAA, NASA, DOD, DLR, ESA and ESTEC technology development programs and technology roadmaps. NASA programs include activities at Langley Research Center, Jet Propulsion Laboratory, Marshall Space Flight Center, Goddard Space Flight Center, and the NASA Institute for Advanced Concepts; NOAA has received funding for a proposed solar sail mission; DLR is designing and fabricating a 20-m laboratory model sail, there are four demonstration missions under study at industry, NASA, DOD and Europe, two new text books on solar sailing were recently published and one new test book is planned. This paper summarizes these on-going developments in solar sails.

  8. Dynamics and control of flexible spinning solar sails under reflectivity modulation

    NASA Astrophysics Data System (ADS)

    Mu, Junshan; Gong, Shengping; Ma, Pengbin; Li, Junfeng

    2015-10-01

    Electrochromic devices have been used for the attitude control of a spinning solar sail in a deep space mission by modulating the reflectivity of the sail membrane. As a flexible spinning solar sail has no rigid structure to support its membrane, the distributed load due to solar radiation will lead to the deformation of the sail membrane, and the control torque generated by reflectivity modulation can introduce oscillatory motion to the membrane. By contrast, the deformation and oscillatory motion of the sail membrane have an impact on the performance of the reflectivity control. This paper investigates the dynamics and control of flexible spinning solar sails under reflectivity modulation. The static deformation of a spinning sail membrane subjected to solar radiation pressure in an equilibrium state is analyzed. The von Karman theory is used to obtain the displacements and the stress distribution in the equilibrium states. A simplified analytical first-order mode is chosen to model the membrane oscillation. The coupled membrane oscillation-attitude-orbit dynamics are considered for a GeoSail formation flying mission. The relative attitude and orbit control of flexible spinning solar sails under reflectivity modulation are numerically tested. The simulations indicate that the membrane deformation and oscillation have a lower impact on the control of the reflectivity modulated sails than the increase of the spinning rate.

  9. In-Space Propulsion (ISP) Solar Sail Propulsion Technology Development

    NASA Technical Reports Server (NTRS)

    Montgomery, Edward E., IV

    2004-01-01

    An overview of the rationale and content for Solar Sail Propulsion (SSP), the on-going project to advance solar technology from technology readiness level 3 to 6 will be provided. A descriptive summary of the major and minor component efforts underway will include identification of the technology providers and a listing of anticipated products Recent important results from major system ground demonstrators will be provided. Finally, a current status of all activities will provided along with the most recent roadmap for the SSP technology development program.

  10. Extrasolar solar-sail trajectories and dark matter

    NASA Astrophysics Data System (ADS)

    Matloff, Gregory L.

    2014-11-01

    Hyper-thin, high-speed solar-photon sail space probes exploring the Sun's Oort comet cloud could also be used to set an upper bound to the concentration of WIMPS (weakly interacting massive particles), one of the suggested (but unconfirmed) forms of dark matter within the vicinity of the solar system. Newton's Shell Theorem would be applied to determine variations in apparent solar mass as the probe moves further out from the Sun. Application of this technique to the trajectories of Pioneer 10/11 reveals that the upper limit to WIMP concentration within ~60 AU of the Sun is ~0.2 Earth masses, as revealed in studies of the Pioneer Anomaly. If the published accuracy of the Pioneer acceleration measurements can be increased by an order of magnitude, probe trajectory measurements out to ~10,000 AU may confirm or falsify the hypothesis that WIMP mass within the solar vicinity is ~3X star mass. It is shown that a space-manufactured ~40-nm thick beryllium hollow-body solar sail deployed from a ~0.07 AU perihelion is a candidate spacecraft for such a mission. Possible science-team organization strategy for a ~100-year mission to ~10,000 AU is discussed.

  11. Dynamic and Static Shape Test/Analysis Correlation of a 10 Meter Quadrant Solar Sail

    NASA Technical Reports Server (NTRS)

    Taleghani, Barmac K.; Lively, Peter S.; Gaspar, James L.; Murphy, David M.; Trautt, Thomas A.

    2005-01-01

    This paper describes finite element analyses and correlation studies to predict deformations and vibration modes/frequencies of a 10-meter quadrant solar sail system. Thin film membranes and booms were analyzed at the component and system-level. The objective was to verify the design and structural responses of the sail system and to mature solar sail technology to a TRL 5. The focus of this paper is in test/analysis correlation.

  12. Status of Solar Sail Material Characterization at NASA's Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Edwards, David L.; Semmel, Charles; Hovater, Mary; Nehles, Mary; Gray, Perry; Hubbs, Whitney; Wertz, George

    2004-01-01

    Near term solar sail propelled science missions are targeting the Lagrange point 1 (Ll) as well as locations sunward of L1 as destinations. These near term missions include the Solar Polar Imager' and the L1 Diamond '. The Environmental Effects Group at NASA's Marshall Space Flight Center (MSFC) continues to actively characterize solar sail material in preparation for these near term solar sail missions. Previous investigations indicated that space environmental effects on sail material thermo-optical properties were minimal and would not significantly affect the propulsion efficiency of the sail. These investigations also indicated that the sail material mechanical stability degrades with increasing radiation exposure. This paper will further quantify the effect of space environmental exposure on the mechanical properties of candidate sail materials. Candidate sail materials for these missions include Aluminum coated Mylar(TradeMark), Teonex(TraeMark), and CP1 (Colorless Polyimide). Experimental data will be presented on sail material response to charged particle radiation and subsequent Hypervelocity Impact (HVI). Data will also be presented indicating mechanical property variations in sail material resulting from electron exposure, proton exposure, and a combined electron and proton exposure. Tabular data consisting of areal density, thickness, thermo-optical, mechanical, and electrical properties, vacuum stability and outgassing will be presented.

  13. Accelerator-Based PIXE and STIM Analysis of Candidate Solar Sail Materials

    SciTech Connect

    Hollerman, W.A.; Stanaland, T.L.; Boudreaux, P.; Elberson, L.; Fontenot, J.; Gates, E.; Greco, R.; McBride, M.; Woodward, A.; Edwards, D.

    2003-08-26

    Solar sailing is a unique form of propulsion where a spacecraft gains momentum from incident photons. A totally reflective sail experiences a pressure of 9.1 {mu}Pa at a distance of 1 AU from the Sun. Since sails are not limited by reaction mass, they provide continual acceleration, reduced only by the lifetime of the lightweight film in the space environment and the distance to the Sun. Practical solar sails can expand the number of possible missions, enabling new concepts that are difficult by conventional means. One of the current challenges is to develop strong, lightweight, and radiation resistant sail materials. This paper will discuss initial results from a Particle Induced X-Ray Emission (PIXE) and Scanning Transmission Ion Microscopy (STIM) analysis of candidate solar sail materials.

  14. Electrodynamic sailing - Beating into the solar wind.

    NASA Technical Reports Server (NTRS)

    Sonett, C. P.; Fahleson, U.; Alfven, H.

    1972-01-01

    The recent suggestion by Alfven (1972) of a novel means of spacecraft propulsion based upon energy extraction from the electromagnetic field of the solar wind is critically reviewed. In response to this review, the original suggestion is somewhat amplified and clarified by its author.

  15. Conceptual analyses of extensible booms to support a solar sail

    NASA Technical Reports Server (NTRS)

    Crawford, R. F.; Benton, M. D.

    1977-01-01

    Extensible booms which could function as the diagonal spars and central mast of an 800 meter square, non-rotating Solar Sailing Vehicle were conceptually designed and analyzed. The boom design concept that was investigated is an extensible lattice boom which is stowed and deployed by elastically coiling and uncoiling its continuous longerons. The seven different free-span lengths in each spar which would minimize the total weights of the spars and mast were determined. Boom weights were calculated by using a semi-empirical formulation which related the overall weight of a boom to the weight of its longerons.

  16. Simulations of Solar Wind Plasma Flow Around a Simple Solar Sail

    NASA Technical Reports Server (NTRS)

    Garrett, Henry B.; Wang, Joseph

    2004-01-01

    In recent years, a number of solar sail missions of various designs and sizes have been proposed (e.g., Geostorm). Of importance to these missions is the interaction between the ambient solar wind plasma environment and the sail. Assuming a typical 1 AU solar wind environment of 400 km/s velocity, 3.5 cu cm density, ion temperature of approx.10 eV, electron temperature of 40 eV, and an ambient magnetic field strength of 10(exp -4) G, a first order estimate of the plasma interaction with square solar sails on the order of the sizes being considered for a Geostorm mission (50 m x 50 m and 75 m x 75 m corresponding to approx.2 and approx.3 times the Debye length in the plasma) is carried out. First, a crude current balance for the sail surface immersed in the plasma environment and in sunlight was used to estimate the surface potential of the model sails. This gave surface potentials of approx.10 V positive relative to the solar wind plasma. A 3-D, Electrostatic Particle-in-Cell (PIC) code was then used to simulate the solar wind flowing around the solar sail. It is assumed in the code that the solar wind protons can be treated as particles while the electrons follow a Boltzmann distribution. Next, the electric field and particle trajectories are solved self-consistently to give the proton flow field, the electrostatic field around the sail, and the plasma density in 3-D. The model sail was found to be surrounded by a plasma sheath within which the potential is positive compared to the ambient plasma and followed by a separate plasma wake which is negative relative to the plasma. This structure departs dramatically from a negatively charged plate such as might be found in the Earth s ionosphere on the night side where both the plate and its negative wake are contiguous. The implications of these findings are discussed as they apply to the proposed Geostorm solar sail mission.

  17. Characterization of Candidate Solar Sail Material Exposed to Space Environmental Effects

    NASA Technical Reports Server (NTRS)

    Edwards, David; Hovater, Mary; Hubbs, Whitney; Wertz, George; Hollerman, William; Gray, Perry

    2003-01-01

    Solar sailing is a unique form of propulsion where a spacecraft gains momentum from incident photons. Solar sails are not limited by reaction mass and provide continual acceleration, reduced only by the lifetime of the lightweight film in the space environment and the distance to the Sun. Once thought to be difficult or impossible, solar sailing has come out of science fiction and into the realm of possibility. Any spacecraft using this method would need to deploy a thin sail that could be as large as many kilometers in extent. The availability of strong, ultra lightweight, and radiation resistant materials will determine the future of solar sailing. The National Aeronautics and Space Administration's Marshall Space Flight Center (MSFC) is concentrating research into the utilization of ultra lightweight materials for spacecraft propulsion. The Space Environmental Effects Team at MSFC is actively characterizing candidate solar sail material to evaluate the thermo-optical and mechanical properties after exposure to space environmental effects. This paper will describe the exposure of candidate solar sail materials to emulated space environmental effects including energetic electrons, combined electrons and Ultraviolet radiation, and hypervelocity impact of irradiated solar sail material. This paper will describe the testing procedure and the material characterization results of this investigation.

  18. Status of Solar Sail Propulsion Within NASA - Moving Toward Interstellar Travel

    NASA Technical Reports Server (NTRS)

    Johnson, Les

    2015-01-01

    NASA is developing solar sail propulsion for two near-term missions and laying the groundwork for their future use in deep space and interstellar precursor missions. Solar sails use sunlight to propel vehicles through space by reflecting solar photons from a large, mirror-like sail made of a lightweight, highly reflective material. This continuous photon pressure provides propellantless thrust, allowing for very high (Delta)V maneuvers on long-duration, deep space exploration. Since reflected light produces thrust, solar sails require no onboard propellant. The Near Earth Asteroid (NEA) Scout mission, managed by MSFC, will use the sail as primary propulsion allowing it to survey and image one or more NEA's of interest for possible future human exploration. Lunar Flashlight, managed by JPL, will search for and map volatiles in permanently shadowed Lunar craters using a solar sail as a gigantic mirror to steer sunlight into the shaded craters. The Lunar Flashlight spacecraft will also use the propulsive solar sail to maneuver into a lunar polar orbit. Both missions use a 6U cubesat architecture, a common an 85 sq m solar sail, and will weigh less than 12 kilograms. Both missions will be launched on the first flight of the Space Launch System in 2018. NEA Scout and Lunar Flashlight will serve as important milestones in the development of solar sail propulsion technology for future, more ambitious missions including the Interstellar Probe - a mission long desired by the space science community which would send a robotic probe beyond the edge of the solar system to a distance of 250 Astronomical Units or more. This paper will summarize the development status of NEA Scout and Lunar Flashlight and describe the next steps required to enable an interstellar solar sail capability.

  19. Solar Sail Topology Variations Due to On-Orbit Thermal Effects

    NASA Technical Reports Server (NTRS)

    Banik, Jeremy A.; Lively, Peter S.; Taleghani, Barmac K.; Jenkins, Chrostopher H.

    2006-01-01

    The objective of this research was to predict the influence of non-uniform temperature distribution on solar sail topology and the effect of such topology variations on sail performance (thrust, torque). Specifically considered were the thermal effects due to on orbit attitude control maneuvers. Such maneuvers are expected to advance the sail to a position off-normal to the sun by as much as 35 degrees; a solar sail initially deformed by typical pre-tension and solar pressure loads may suffer significant thermally induced strains due to the non-uniform heating caused by these maneuvers. This on-orbit scenario was investigated through development of an automated analytical shape model that iterates many times between sail shape and sail temperature distribution before converging on a final coupled thermal structural affected sail topology. This model utilizes a validated geometrically non-linear finite element model and a thermal radiation subroutine. It was discovered that temperature gradients were deterministic for the off-normal solar angle cases as were thermally induced strains. Performance effects were found to be moderately significant but not as large as initially suspected. A roll torque was detected, and the sail center of pressure shifted by a distance that may influence on-orbit sail control stability.

  20. Attitude Dynamics of Spinning Solar Sail “IKAROS” Considering Thruster Plume

    NASA Astrophysics Data System (ADS)

    Mori, Osamu; Shirasawa, Yoji; Sawada, Hirotaka; Tsuda, Yuichi; Funase, Ryu; Saiki, Takanao; Yamamoto, Takayuki; Motooka, Norizumi; Jifuku, Ryo

    In this paper, the attitude dynamics of IKAROS, which is spinning solar sail, are presented. The first mode model of out-of-plane sail deformation (FMM) and multi-particle model (MPM) are introduced to analyze the oscillatory motion of the spinning solar sail. Three oscillation modes are derived from the FMM. They are caused by the nutation motion of the main body, as well as the nutation motion and the out-of-plane oscillation of the sail. The precise attitude motion after sail deployment and reorientation using thrusters is calculated using the MPM considering thruster plume. The IKAROS flight data of the nutation angular velocities of the main body after sail deployment or reorientation using thrusters are nearly equal to the analytical data found using the FMM and MPM.

  1. A dynamical system approach for the station keeping of a solar sail

    NASA Astrophysics Data System (ADS)

    Farrés, Ariadna; Jorba, Àngel

    2008-06-01

    In this paper we have considered the movement of a solar sail in the Sun-Earth system. As a model we have used the restricted three-body problem adding the solar radiation pressure. It can be seen that we have a two-dimensional family of equilibria parameterized by the two angles defining the sail's orientation. Most of these equilibrium points are unstable and require a control strategy to keep the sail close to them. We have designed a control strategy that uses the knowledge of the position of the invariant manifolds and how they vary when the sail orientation is changed. We have tested our strategy with two known missions: the Polar Observer and the Geostorm Warning Mission. Simulations of up to 30 years have been performed taking into account errors on the position and velocity determination of the sail and on the sail's orientation.

  2. On the station keeping of a solar sail in the elliptic Sun-Earth system

    NASA Astrophysics Data System (ADS)

    Farrés, Ariadna; Jorba, Àngel

    2011-12-01

    In this work we focus on the dynamics of a solar sail in the Sun-Earth Elliptic Restricted Three-Body Problem with solar radiation pressure. The considered situation is the motion of a sail close to the L1 point, but displacing the equilibrium point with the sail so that it is possible to have continuous communication with the Earth. In previous works we derived a station keeping strategy for this situation but using the Circular RTBP as a model. In this paper we discuss the effect of the eccentricity in the region close to the sail-displaced L1 point of the Circular RTBP. Then we show how to use the information on this dynamics to design a station keeping strategy. Finally, we apply these results to the GeoStorm mission, including errors in the sail orientation and on the estimation of the position of the sail in the simulations.

  3. DAPHNE: Energy Generation and storage, using Solar Sails

    NASA Astrophysics Data System (ADS)

    Argelagós Palau, Ana Maria; Savio Bradford, Brandon

    Space travel is still in it's adolescent stages. Having embarked beyond the limit of our atmosphere for a mere 50 years, it is easy to imagine how much is yet to be discovered, in other solar systems and our own. One of the main factors that slow us down is the need for Energy. Long distance space travel requires a lot of energy, both for propulsion and operations alike. The principle of solar sails shows that the momentum of solar energy can be used beneficially, as can be seen in NASA's Sun-Jammer project. So, why not generate energy from this system? The DAPHNE system will utilize the simple principle of wind mills that is used here on Earth; using the force created by Solar wind to rotate an axle that in turn, generates energy. And this mill can be used to recharge spacecraft that need to fly further than it's own initial energy system will allow. Another benefit to developing this system is the fact that it is an alternative to nuclear energy generation for space, that a lot of modern research is being done on. The DAPHNE system can be considered a solution to long term propellant storage in space for interplanetary and interstellar travel. This paper proposes the design of an energy recharge technology, we called DAPHNE, which will utilize Nanotechnology, using solar sails to generate and store energy for future long-distance space craft to dock with, recharge and continue on their journey/mission. Examples of spacecraft in development that might benefit from a recharging station are the LISA Pathfinder, terrestrial exploration missions and eventually, the long interstellar missions that will be launched in the distant future. Thereby, allowing mankind to push the boundaries of our solar system and accelerate our ability to know what's out there. This technology would help the future generations of Space researchers move further than we can.

  4. Power Beamed Photon Sails: New Capabilities Resulting From Recent Maturation Of Key Solar Sail And High Power Laser Technologies

    SciTech Connect

    Montgomery, Edward E. IV

    2010-05-06

    This paper revisits some content in the First International Symposium on Beamed Energy Propulsion in 2002 related to the concept of propellantless in-space propulsion utilizing an external high energy laser to provide momentum to an ultralightweight (gossamer) spacecraft. The design and construction of the NanoSail-D solar sail demonstration spacecraft has demonstrated in space flight hardware the concept of small, very light--yet capable--spacecraft. The results of the Joint High Power Solid State Laser (JHPSSL) have also increased the effectiveness and reduced the cost of an entry level laser source. This paper identifies the impact from improved system parameters on current mission applications.

  5. Power Beamed Photon Sails: New Capabilities Resulting From Recent Maturation Of Key Solar Sail And High Power Laser Technologies

    NASA Astrophysics Data System (ADS)

    Montgomery, Edward E.

    2010-05-01

    This paper revisits some content in the First International Symposium on Beamed Energy Propulsion in 2002 related to the concept of propellantless in-space propulsion utilizing an external high energy laser to provide momentum to an ultralightweight (gossamer) spacecraft. The design and construction of the NanoSail-D solar sail demonstration spacecraft has demonstrated in space flight hardware the concept of small, very light—yet capable—spacecraft. The results of the Joint High Power Solid State Laser (JHPSSL) have also increased the effectiveness and reduced the cost of an entry level laser source. This paper identifies the impact from improved system parameters on current mission applications.

  6. Utilization of an H-reversal trajectory of a solar sail for asteroid deflection

    NASA Astrophysics Data System (ADS)

    Gong, Sheng-Ping; Li, Jun-Feng; Zeng, Xiang-Yuan

    2011-10-01

    Near Earth Asteroids have a possibility of impacting the Earth and always represent a threat. This paper proposes a way of changing the orbit of the asteroid to avoid an impact. A solar sail evolving in an H-reversal trajectory is utilized for asteroid deflection. Firstly, the dynamics of the solar sail and the characteristics of the H-reversal trajectory are analyzed. Then, the attitude of the solar sail is optimized to guide the sail to impact the target asteroid along an H-reversal trajectory. The impact velocity depends on two important parameters: the minimum solar distance along the trajectory and lightness number of the solar sail. A larger lightness number and a smaller solar distance lead to a higher impact velocity. Finally, the deflection capability of a solar sail impacting the asteroid along the H-reversal trajectory is discussed. The results show that a 10 kg solar sail with a lead-time of one year can move Apophis out of a 600-m keyhole area in 2029 to eliminate the possibility of its resonant return in 2036.

  7. Attitude Dynamics and Control of Solar Sails with Articulated Vanes

    NASA Technical Reports Server (NTRS)

    Mettler, Edward; Acikmese, A. Behcet; Ploen, Scott R.

    2005-01-01

    In this paper we develop a robust nonlinear algorithm for the attitude control of a solar sailcraft with M single degree-of-freedom articulated control vanes. A general attitude controller that tracks an admissible trajectory while rejecting disturbances such as torques due to center-of-mass to center-of-pressure offsets is applied to this problem. We then describe a methodology based on nonlinear programming to allocate the required control torques among the control vanes. A simplified allocation strategy is then applied to a solar sail with four articulated control vanes, and simulation results are given. The performance of the control algorithm and possible limitations of vane-only control are then discussed.

  8. Thermo-Optical and Mechanical Property Testing of Candidate Solar Sail Materials

    NASA Technical Reports Server (NTRS)

    Hollerman, WIlliam A.; Stanaland, T. L.; Womack, F.; Edwards, David; Hubbs, Whitney; Semmel, Charles

    2003-01-01

    Solar sailing is a unique form of propulsion where a spacecraft gains momentum from incident photons. Since sails are not limited by reaction mass, they provide continual acceleration, reduced only by the lifetime of the lightweight film in the space environment and the distance to the Sun. Practical solar sails can expand the number of possible missions, enabling new concepts that are difficult by conventional means. The National Aeronautics and Space Administration's Marshall Space Flight Center (MSFC) is concentrating research into the utilization of ultra-lightweight materials for spacecraft propulsion. Solar sails are generally composed of a highly reflective metallic front layer, a thin polymeric substrate, and occasionally a highly emissive back surface. The Space Environmental Effects Team at MSFC is actively characterizing candidate sails to evaluate the thermo-optical and mechanical properties after exposure to electrons. This poster will discuss the preliminary results of this research.

  9. Extension of Earth-Moon libration point orbits with solar sail propulsion

    NASA Astrophysics Data System (ADS)

    Heiligers, Jeannette; Macdonald, Malcolm; Parker, Jeffrey S.

    2016-07-01

    This paper presents families of libration point orbits in the Earth-Moon system that originate from complementing the classical circular restricted three-body problem with a solar sail. Through the use of a differential correction scheme in combination with a continuation on the solar sail induced acceleration, families of Lyapunov, halo, vertical Lyapunov, Earth-centred, and distant retrograde orbits are created. As the solar sail circular restricted three-body problem is non-autonomous, a constraint defined within the differential correction scheme ensures that all orbits are periodic with the Sun's motion around the Earth-Moon system. The continuation method then starts from a classical libration point orbit with a suitable period and increases the solar sail acceleration magnitude to obtain families of orbits that are parametrised by this acceleration. Furthermore, different solar sail steering laws are considered (both in-plane and out-of-plane, and either fixed in the synodic frame or fixed with respect to the direction of Sunlight), adding to the wealth of families of solar sail enabled libration point orbits presented. Finally, the linear stability properties of the generated orbits are investigated to assess the need for active orbital control. It is shown that the solar sail induced acceleration can have a positive effect on the stability of some orbit families, especially those at the L2 point, but that it most often (further) destabilises the orbit. Active control will therefore be needed to ensure long-term survivability of these orbits.

  10. On Possibility of Direct Asteroid Deflection by Electric Solar Wind Sail

    NASA Astrophysics Data System (ADS)

    Merikallio, Sini; Janhunen, Pekka

    2010-05-01

    The Electric Solar Wind Sail (E-sail) is a new propulsion method for interplanetary travel which was invented in 2006 and is currently under development. The E-sail uses charged tethers to extract momentum from the solar wind particles to obtain propulsive thrust. According to current estimates, the E-sail is 2-3 orders of magnitude better than traditional propulsion methods (chemical rockets and ion engines) in terms of produced lifetime-integrated impulse per propulsion system mass. Here we analyze the problem of using the E-sail for directly deflecting an Earth-threatening asteroid. The problem then culminates into how to attach the E-sail device to the asteroid. We assess a number of alternative attachment strategies and arrive at a recommendation of using the gravity tractor method because of its workability for a wide variety of asteroid types. We also consider possible techniques to scale up the E-sail force beyond the baseline one Newton level to deal with more imminent or larger asteroid or cometary threats. As a baseline case we consider a 3 million ton asteroid which can be deflected with a baseline 1 N E-sail in 5-10 years. Once developed, the E-sail would appear to provide a safe and reasonably low-cost way of deflecting dangerous asteroids and other heavenly bodies in cases where the collision threat becomes known several years in advance.

  11. Near-Earth Asteroid Flyby Survey Mission Using Solar Sailing Technology

    NASA Astrophysics Data System (ADS)

    Bando, Mai; Yamakawa, Hiroshi

    2011-10-01

    The purpose of this paper is to investigate the possibility of on asteroid (NEA) survey mission enabled by advanced solar sailing technology. The study is focused not on the solar sail spacecraft itself but on its orbital dynamics to realize the missions. A novel NEA flyby survey mission with a lightweight solar sail spacecraft to increase the accessibility to NEA flybys located in the vicinity of the Earth's orbit is proposed. A numerical study suggests that our approach increases the opportunities in proximity to NEAs, which have eccentric and inclined orbits.

  12. Deployment Technology of a Heliogyro Solar Sail for Long Duration Propulsion

    NASA Technical Reports Server (NTRS)

    Peerawan, Wiwattananon; Bryant, Robert G.; Edmonson, William W.; Moore, William B.; Bell, Jared M.

    2015-01-01

    Interplanetary, multi-mission, station-keeping capabilities will require that a spacecraft employ a highly efficient propulsion-navigation system. The majority of space propulsion systems are fuel-based and require the vehicle to carry and consume fuel as part of the mission. Once the fuel is consumed, the mission is set, thereby limiting the potential capability. Alternatively, a method that derives its acceleration and direction from solar photon pressure using a solar sail would eliminate the requirement of onboard fuel to meet mission objectives. MacNeal theorized that the heliogyro-configured solar sail architecture would be lighter, less complex, cheaper, and less risky to deploy a large sail area versus a masted sail. As sail size increases, the masted sail requires longer booms resulting in increased mass, and chaotic uncontrollable deployment. With a heliogyro, the sail membrane is stowed as a roll of thin film forming a blade when deployed that can extend up to kilometers. Thus, a benefit of using a heliogyro-configured solar sail propulsion technology is the mission scalability as compared to masted versions, which are size constrained. Studies have shown that interplanetary travel is achievable by the heliogyro solar sail concept. Heliogyro solar sail concept also enables multi-mission missions such as sample returns, and supply transportation from Earth to Mars as well as station-keeping missions to provide enhanced warning of solar storm. This paper describes deployment technology being developed at NASA Langley Research Center to deploy and control the center-of-mass/center-of-pressure using a twin bladed heliogyro solar sail 6-unit (6U) CubeSat. The 6U comprises 2x2U blade deployers and 2U for payload. The 2U blade deployers can be mounted to 6U or larger scaled systems to serve as a non-chemical in-space propulsion system. A single solar sail blade length is estimated to be 2.4 km with a total area from two blades of 720 m2; total allowable weight

  13. An analysis of thrust of a realistic solar sail with focus on a flight validation mission in a geocentric orbit

    NASA Astrophysics Data System (ADS)

    Campbell, Bruce A.

    Several scientifically important space flight missions have been identified that, at this time, can only be practically achieved using a solar sail propulsion system. These missions take advantage of the potentially continuous force on the sail, provided by solar radiation, to produce significant changes in the spacecraft's velocity, in both magnitude and/or direction, without the need for carrying the enormous amount of fuel that conventional propulsion systems would require to provide the same performance. However, to provide thrust levels that would support these missions requires solar sail areas in the (tens of) thousands of square meter sizes. To realize this, many technical areas must be developed further and demonstrated in space before solar sails will be accepted as a viable space mission propulsion system. One of these areas concerns understanding the propulsion performance of a realistic solar sail well enough for mission planning. Without this understanding, solar sail orbits could not be predicted well enough to meet defined mission requirements, such as rendezvous or station-keeping, and solar sail orbit optimization, such as minimizing flight time, could be close to impossible. In most mission studies, either an "ideal" sail's performance is used for mission planning, or some top-level assumptions of certain nonideal sail characteristics are incorporated to give a slightly better estimate of the sail performance. This paper identifies the major sources of solar sail thrust performance uncertainty, and analyzes the most significant ones to provide a more comprehensive understanding of thrust generation by a "realistic" solar sail. With this understanding, mission planners will be able to more confidently and accurately estimate the capabilities of such a system. The first solar sail mission will likely be a system validation mission, using a relatively small sail in a geocentric (Earth-centered) orbit. The author has been involved in conceptual

  14. Development of Oscillation-Free Attitude Maneuvering System for Spinning Solar Sail

    NASA Astrophysics Data System (ADS)

    Funase, Ryu; Hanaoka, Fuminori; Mori, Osamu; Tsuda, Yuichi; Kawaguchi, Junichiro

    Solar sail is one of the promising propulsion systems for future deep space exploration missions as it does not require any fuel to acquire propulsive force. Although folding method and deployment mechanism of the sail have been intensively developed, attitude control of the solar sail, which is necessary for the orbital control by the solar sail, has not been much studied. This paper discusses the attitude dynamics and the control method of a spinning type solar sail spacecraft. The spinning type solar sail, where the sail equipped around the spacecraft hub is to be deployed and extended by centrifugal force, has no rigid structure supporting its membrane. This type of mechanism has the advantage in its simple and lightweight structure, however, the attitude control is difficult due to the flexibility of the membrane. In this paper, we introduced a mathematical dynamics model including first oscillation mode of the membrane which can handle coupled motion of a rigid spacecraft and a flexible membrane, and analytically developed a controller that can avoid unnecessary oscillatory motion. The performance of the controller was verified by numerical simulations using more precise multi-particle numerical model.

  15. Experimental and Numerical Correlation of Gravity Sag in Solar Sail Quality Membranes

    NASA Technical Reports Server (NTRS)

    Black, Jonathan T.; Leifer, Jack; DeMoss, Joshua A.; Walker, Eric N.; Belvin, W. Keith

    2004-01-01

    Solar sails are among the most studied members of the ultra-lightweight and inflatable (Gossamer) space structures family due to their potential to provide propellentless propulsion. They are comprised of ultra-thin membrane panels that, to date, have proven very difficult to experimentally characterize and numerically model due to their reflectivity and flexibility, and the effects of gravity sag and air damping. Numerical models must be correlated with experimental measurements of sub-scale solar sails to verify that the models can be scaled up to represent full-sized solar sails. In this paper, the surface shapes of five horizontally supported 25 micron thick aluminized Kapton membranes were measured to a 1.0 mm resolution using photogrammetry. Several simple numerical models closely match the experimental data, proving the ability of finite element simulations to predict actual behavior of solar sails.

  16. Achievement of IKAROS — Japanese deep space solar sail demonstration mission

    NASA Astrophysics Data System (ADS)

    Tsuda, Yuichi; Mori, Osamu; Funase, Ryu; Sawada, Hirotaka; Yamamoto, Takayuki; Saiki, Takanao; Endo, Tatsuya; Yonekura, Katsuhide; Hoshino, Hirokazu; Kawaguchi, Jun'ichiro

    2013-02-01

    This paper describes achievements of the IKAROS project, the world's first successful interplanetary solar power sail technology demonstration mission. It was developed by the Japan Aerospace Exploration Agency (JAXA) and was launched from Tanegashima Space Center on May 21, 2010. IKAROS successfully deployed a 20 m-span sail on June 9, 2010. Since then IKAROS has performed interplanetary solar-sailing taking advantage of an Earth-Venus leg of the interplanetary trajectory. We declared the completion of the nominal mission phase in the end of December 2010 when IKAROS successfully passed by Venus with the assist of solar sailing. This paper describes the overview of the IKAROS spacecraft system, how the world's first interplanetary solar sailer has been operated and what were achieved by the end of the nominal mission phase.

  17. Hybrid solar sail and solar electric propulsion for novel Earth observation missions

    NASA Astrophysics Data System (ADS)

    Ceriotti, Matteo; McInnes, Colin R.

    2011-11-01

    In this paper we propose a pole-sitter spacecraft hybridising solar electric propulsion (SEP) and solar sailing. The intriguing concept of a hybrid propulsion spacecraft is attractive: by combining the two forms of propulsion, the drawbacks of the two systems cancel each other, potentially enabling propellant mass saving, increased reliability, versatility and lifetime over the two independent systems. This almost completely unexplored concept will be applied to the continuous monitoring of the Earth's polar regions through a pole-sitter, i.e. a spacecraft that is stationary above one pole of the Earth. The continuous, hemispherical, real-time view of the pole will enable a wide range of new applications for Earth observation and telecommunications. In this paper, families of 1-year-periodic, minimum-propellant orbits are found, for different values of the sail lightness number and distance from the pole. The optimal control problem is solved using a pseudo-spectral method. The process gives a reference control to maintain these orbits. In addition, for stability issues, a feedback control is designed to guarantee station-keeping in the presence of injection errors, sail degradation and temporary SEP failure. Results show that propellant mass can be saved using a medium-sized solar sail. Finally, it is shown that the feedback control is able to maintain the spacecraft on-track with only minimal additional effort from the SEP thruster.

  18. Optimal solar sail transfers between Halo orbits of different Sun-planet systems

    NASA Astrophysics Data System (ADS)

    Heiligers, Jeannette; Mingotti, Giorgio; McInnes, Colin R.

    2015-03-01

    This paper investigates time-optimal solar sail trajectories between Libration Point Orbits (LPOs) of different circular restricted Sun-planet three-body systems. Key in the investigations is the search for transfers that require little steering effort to enable the transfers with low-control authority solar sail-like devices such as SpaceChips. Two transfers are considered: (1) from a Sun-Earth L2-Halo orbit to a Sun-Mars L1-Halo orbit and (2) from a Sun-Earth L1-Halo orbit to a Sun-Mercury L2-Halo orbit. The optimal control problem to find these time-optimal transfers is derived, including a constraint to mimic limited steering capabilities, and is solved with a direct pseudospectral method for which novel first guess solutions are developed. For a near-term sail performance comparable to that of NASA's Sunjammer sail, the results show transfers that indeed require very little steering effort: the sail acceleration vector can be bounded to a cone around the Sun-sail line with a half-angle of 7.5 deg. These transfers can serve a range of novel solar sail applications covering the entire spectrum of sail length-scales: micro-sized SpaceChips could establish a continuous Earth-Mars communication link, a traditional-sized sail provides opportunities for in-situ observations of Mercury and a future kilometer-sized sail could create an Earth-Mars cargo transport gateway for human exploration of Mars.

  19. Solar Sail Models and Test Measurements Correspondence for Validation Requirements Definition

    NASA Technical Reports Server (NTRS)

    Ewing, Anthony; Adams, Charles

    2004-01-01

    Solar sails are being developed as a mission-enabling technology in support of future NASA science missions. Current efforts have advanced solar sail technology sufficient to justify a flight validation program. A primary objective of this activity is to test and validate solar sail models that are currently under development so that they may be used with confidence in future science mission development (e.g., scalable to larger sails). Both system and model validation requirements must be defined early in the program to guide design cycles and to ensure that relevant and sufficient test data will be obtained to conduct model validation to the level required. A process of model identification, model input/output documentation, model sensitivity analyses, and test measurement correspondence is required so that decisions can be made to satisfy validation requirements within program constraints.

  20. Mass breakdown model of solar-photon sail shuttle: The case for Mars

    NASA Astrophysics Data System (ADS)

    Vulpetti, Giovanni; Circi, Christian

    2016-02-01

    The main aim of this paper is to set up a many-parameter model of mass breakdown to be applied to a reusable Earth-Mars-Earth solar-photon sail shuttle, and analyze the system behavior in two sub-problems: (1) the zero-payload shuttle, and (2) given the sailcraft sail loading and the gross payload mass, find the sail area of the shuttle. The solution to the subproblem-1 is of technological and programmatic importance. The general analysis of subproblem-2 is presented as a function of the sail side length, system mass, sail loading and thickness. In addition to the behaviors of the main system masses, useful information for future work on the sailcraft trajectory optimization is obtained via (a) a detailed mass model for the descent/ascent Martian Excursion Module, and (b) the fifty-fifty solution to the sailcraft sail loading breakdown equation. Of considerable importance is the evaluation of the minimum altitude for the rendezvous between the ascent rocket vehicle and the solar-photon sail propulsion module, a task performed via the Mars Climate Database 2014-2015. The analysis shows that such altitude is 300 km; below it, the atmospheric drag prevails over the solar-radiation thrust. By this value, an example of excursion module of 1500 kg in total mass is built, and the sailcraft sail loading and the return payload are calculated. Finally, the concept of launch opportunity-wide for a shuttle driven by solar-photon sail is introduced. The previous fifty-fifty solution may be a good initial guess for the trajectory optimization of this type of shuttle.

  1. Analysis of Surface Charging for a Candidate Solar Sail Mission Using NASCAP-2K

    NASA Technical Reports Server (NTRS)

    Parker, Linda Neergaard; Minow, Joseph L.; Davis, V. A.; Mandell, Myron; Gardner, Barbara

    2005-01-01

    The characterization of the electromagnetic interaction for a solar sail in the solar wind environment and identification of viable charging mitigation strategies are critical solar sail mission design tasks. Spacecraft charging has important implications both for science applications and for lifetime and reliability issues of sail propulsion systems. To that end, surface charging calculations of a candidate 150-meter-class solar sail spacecraft for the 0.5 AU solar polar and 1.9 AU LI solar wind environments are performed. A model of the spacecraft with candidate materials having appropriate electrical properties is constructed using Object Toolkit. The spacecraft charging analysis is performed using Nascap-2k. the NASA/AFRL sponsored spacecraft charging analysis tool. Nominal and atypical solar wind environments appropriate for the 0.5 AU and 1.0 AU missions are used to establish current collection of solar wind ions and electrons. Finally, a geostationary orbit environment case is included to demonstrate a bounding example of extreme (negative) charging of a solar sail spacecraft. Results from the charging analyses demonstrate that minimal differential potentials (and resulting threat of electrostatic discharge) occur when the spacecraft is constructed entirely of conducting materials, as anticipated from standard guidelines for mitigation of spacecraft charging issues. Examples with dielectric materials exposed to the space environment exhibit differential potentials ranging from a few volts to extreme potentials in the kilovolt range.

  2. Analysis of Surface Charging for a Candidate Solar Sail Mission Using Nascap-2k

    NASA Technical Reports Server (NTRS)

    Parker, Linda Neergaard; Minow, Joseph I.; Davis, Victoria; Mandell, Myron; Gardner, Barbara

    2005-01-01

    The characterization of the electromagnetic interaction for a solar sail in the solar wind environment and identification of viable charging mitigation strategies are critical solar sail mission design task. Spacecraft charging has important implications both for science applications and for lifetime and reliability issues of sail propulsion systems. To that end, surface charging calculations of a candidate 150-meter-class solar sail spacecraft for the 0.5 AU solar polar and 1.0 AU L1 solar wind environments are performed. A model of the spacecraft with candidate materials having appropriate electrical properties is constructed using Object Toolkit. The spacecraft charging analysis is performed using Nascap-2k, the NASA/AFRL sponsored spacecraft charging analysis tool. Nominal and atypical solar wind environments appropriate for the 0.5 AU and 1.0 AU missions are used to establish current collection of solar wind ions and electrons. Finally, a geostationary orbit environment case is included to demonstrate a bounding example of extreme (negative) charging of a solar sail spacecraft. Results from the charging analyses demonstrate that minimal differential potentials (and resulting threat of electrostatic discharge) occur when the spacecraft is constructed entirely of conducting materials, as anticipated from standard guidelines for mitigation of spacecraft charging issues. Examples with dielectric materials exposed to the space environment exhibit differential potentials ranging from a few volts to extreme potentials in the kilovolt range.

  3. Effect of a drag force due to absorption of solar radiation on solar sail orbital dynamics

    NASA Astrophysics Data System (ADS)

    Kezerashvili, Roman Ya.; Vázquez-Poritz, Justin F.

    2013-03-01

    While solar electromagnetic radiation can be used to propel a solar sail, it is shown that the Poynting-Robertson effect related to the absorbed portion of the radiation leads to a drag force in the transversal direction. The Poynting-Robertson effect is considered for escape trajectories, Heliocentric bound orbits and non-Keplerian bound orbits. For escape trajectories, this drag force diminishes the cruising velocity, which has a cumulative effect on the Heliocentric distance. For Heliocentric and non-Keplerian bound orbits, the Poynting-Robertson effect decreases its orbital speed, thereby causing it to slowly spiral towards the Sun. Since the Poynting-Robertson effect is due to the absorbed portion of the electromagnetic radiation, degradation of a solar sail implies that this effect becomes enhanced during a mission.

  4. A passive, sun-pointing, millimeter-scale solar sail

    NASA Astrophysics Data System (ADS)

    Atchison, Justin A.; Peck, Mason A.

    2010-07-01

    Taking inspiration from the orbital dynamics of dust, we find that spacecraft length scaling is a means of enabling infinite-impulse orbits that require no feedback control. Our candidate spacecraft is a 25 μm thick, 1 cm square silicon chip equipped with signal transmitting circuitry. This design reduces the total mass to less than 7.5 mg and enables the spacecraft bus itself to serve as a solar sail with characteristic acceleration on the order of 0.1 mm/s 2. It is passive in that it maneuvers with no closed-loop actuation of orbital or attitude states. The unforced dynamics that result from an insertion orbit and a launch-vehicle separation determine its subsequent state evolution. We have developed a system architecture that uses solar radiation torques to maintain a sun-pointing heading and can be fabricated with standard microfabrication processes. This architecture has potential applications in heliocentric, geocentric, and three-body orbits.

  5. MESSENGER's use of solar sailing for cost and risk reduction

    NASA Astrophysics Data System (ADS)

    O'Shaughnessy, Daniel J.; McAdams, James V.; Bedini, Peter D.; Calloway, Andrew B.; Williams, Kenneth E.; Page, Brian R.

    2014-01-01

    The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission used six planetary gravity assists in order to enable capture into orbit about Mercury. A key element of MESSENGER's successful trajectory was achieving the proper gravity assist from each planetary flyby. The criticality of the MESSENGER gravity assists levied tight accuracy requirements on the planetary-flyby targeting. Major errors could have precluded Mercury orbit insertion or required modifications to the trajectory that increased mission complexity, cost, and risk by requiring additional Mercury flybys and extending mission duration. Throughout the mission, MESSENGER modified its strategy for achieving accurate planetary flybys. By using solar sailing, the MESSENGER team was able to eliminate all of the flyby approach maneuvers without sacrificing flyby accuracy, thereby saving mission ΔV margin. The elimination of these approach maneuvers also markedly reduced mission risk, as these approach maneuvers were nominally planned during a time of heightened sensitivity to errors and precluded unique flyby science opportunities. The paradigm shift used by MESSENGER may be useful for other interplanetary missions, particularly if their trajectories require gravity assists in the inner solar system.

  6. Development of Modal Test Techniques for Validation of a Solar Sail Design

    NASA Technical Reports Server (NTRS)

    Gaspar, James L.; Mann, Troy; Behun, Vaughn; Wilkie, W. Keats; Pappa, Richard

    2004-01-01

    This paper focuses on the development of modal test techniques for validation of a solar sail gossamer space structure design. The major focus is on validating and comparing the capabilities of various excitation techniques for modal testing solar sail components. One triangular shaped quadrant of a solar sail membrane was tested in a 1 Torr vacuum environment using various excitation techniques including, magnetic excitation, and surface-bonded piezoelectric patch actuators. Results from modal tests performed on the sail using piezoelectric patches at different positions are discussed. The excitation methods were evaluated for their applicability to in-vacuum ground testing and to the development of on orbit flight test techniques. The solar sail membrane was tested in the horizontal configuration at various tension levels to assess the variation in frequency with tension in a vacuum environment. A segment of a solar sail mast prototype was also tested in ambient atmospheric conditions using various excitation techniques, and these methods are also assessed for their ground test capabilities and on-orbit flight testing.

  7. Preliminary Design and Fabrication Assessment for Two Solar Sail Candidates

    NASA Technical Reports Server (NTRS)

    Weis, R.

    1977-01-01

    Primary emphasis is directed to the spinning sail design and fabrication assessment. Several methods of fabricating the spinning sail blades are presented and compared. Evaluations are made of each proposed design, as well as the baseline design. These efforts resulted in the recommendation of an apparent optimum design and fabrication plan with an assessment of the major advantages/disadvantages of each concept considered.

  8. Analysis of Surface Charging for a Candidate Solar Sail Mission Using Nascap-2k

    NASA Technical Reports Server (NTRS)

    Neergaard, Linda F.; Davis, Victoria A.; Gardner, Barbara; Mandell, Myron; Minow, Joseph I.

    2004-01-01

    The characterization of the electromagnetic interaction for a solar sail in the solar wind environment, and identification of viable charging mitigation strategies, is a critical solar sail mission design task, as spacecraft charging has important implications both for science applications and for sail lifetime. To that end, we have pexformed some preliminary surface charging calculations of a candidate 150 meter class solar sail spacecraft for the 0.5 AU solar polar orbit and a 1.0 AU L1 orbit. We construct a model of the spacecraft with candidate materials having appropriate electrical properties using Object Toolkit and perform the spacecraft charging analysis using Nascap-2k, the NASA/AFRL sponsored spacecraft charging analysis tool. We use mean and extreme solar wind environments appropriate for the 0.5 AU and 1.0 AU missions to establish current collection of solar wind ions and electrons. In addition, we include a geostationary orbit case to demonstrate a bounding example of extreme (negative) charging of a solar sail spacecraft in the geostationary orbit environment. Results from the charging analysis demonstrate that minimal differential potentials (and resulting threat of electrostatic discharge) occur when the spacecraft is constructed entirely of conducting materials, as expected. Examples with dielectric materials exposed to the space environment exhibit differential potentials ranging from a few volts to extreme potentials in the kilovolt range. Recommendations for further analyses include calculations of wake effects, surface current densities, and environments effects on conductivities.

  9. Analysis Of Surface Charging For A Candidate Solar Sail Mission Using Nascap-2k

    NASA Technical Reports Server (NTRS)

    Minow, Joseph; Parker, Linda Neergaard; Davis, Victoria

    2005-01-01

    The characterization of the electromagnetic interaction for a solar sail in the solar wind environment, and identification of viable charging mitigation strategies, is a critical solar sail mission design task, as spacecraft charging has important implications both for science applications and for sail lifetime. To that end, we have performed surface charging calculations of a candidate 150-meter-class solar sail spacecraft for the 0.5 solar polar orbit and a 1.0 AU L1 orbit. We construct a model of the spacecraft with candidate materials having appropriate electrical properties using Object Toolkit and perform the spacecraft charging analysis using NASCAP-2k, the NASA/AFRL sponsored spacecraft charging analysis tool. We use nominal and atypical solar wind environments appropriate for the 0.5 AU and 1.0 AU missions to establish current collection of solar wind ions and electrons. In addition, we include a geostationary orbit case to demonstrate a bounding example of extreme (negative) charging of a solar sail spacecraft in the geostationary orbit environment. Results form the charging analysis demonstrate that minimal differential potentials (and resulting threat of electrostatic discharge) occur when the spacecraft is constructed entirely of conducting materials, as expected. Examples with dielectric materials exposed to the space environment exhibit differential potentials ranging from a few volts to extreme potentials in the kilovolt range.

  10. Analysis of Surface Charging for a Candidate Solar Sail Mission Using NASCAP-2K

    NASA Technical Reports Server (NTRS)

    Parker, Linda Neergaard; Minow, Joseph I.; Davis, V. A.; Gardner, Barbara; Mandell, Myron

    2004-01-01

    The characterization of the electromagnetic interaction for a solar sail in the solar wind environment, and identification of viable charging mitigation strategies, is a critical solar sail mission design task, as spacecraft charging has important implications both for science applications and for sail lifetime. To that end, we have performed surface charging calculations of a candidate 150-meter-class solar sail spacecraft for the 0.5 AU solar polar orbit and a 1.0 AU L1 orbit. We construct a model of the spacecraft with candidate materials having appropriate electrical properties using Object Toolkit and perform the spacecraft charging analysis using NASCAP-2k, the NASA/AFRL sponsored spacecraft charging analysis tool. We use nominal and atypical solar wind environments appropriate for the 0.5 AU and 1.0 AU missions to establish current collection of solar wind ions and electrons. In addition, we include a geostationary orbit case to demonstrate a bounding example of extreme (negative) charging of a solar sail spacecraft in the geostationary orbit environment. Results from the charging analysis demonstrate that minimal differential potentials (and resulting threat of electrostatic discharge) occur when the spacecraft is constructed entirely of conducting materials, as expected. Examples with dielectric materials exposed to the space environment exhibit differential potentials ranging from a few volts to extreme potentials in the kilovolt range.

  11. Physics of Thrust Prediction of the Solar Wind Electric Sail Propulsion System

    NASA Astrophysics Data System (ADS)

    Janhunen, P.

    2010-09-01

    The electric solar wind sail is a newly invented way for using the solar wind dynamic pressure for providing thrust for a spacecraft. An electric sail spacecraft deploys long, thin, conducting tethers which are centrifugally stretched and kept in a high positive potential by an onboard electron gun. Scientifically, the essential problem is to predict the thrust force per unit length that the plasma stream exerts on the tether when the tether is kept in a 15-40 kV voltage. Recently, theoretical arguments were put forward which suggest that trapped electrons are almost completely absent from the electric sail. In view of these arguments, we make here the assumption that trapped electrons are absent and proceed to derive a simplified analytical thrust formula. This formula predicts about five times higher electric sail thrust than the original estimates which included trapped electrons.

  12. Structural Analysis of an Inflation-Deployed Solar Sail With Experimental Validation

    NASA Technical Reports Server (NTRS)

    Sleight, David W.; Michii, Yuki; Lichodziejewski, David; Derbes, Billy; Mann, Troy O.

    2005-01-01

    Under the direction of the NASA In-Space Propulsion Technology Office, the team of L Garde, NASA Jet Propulsion Laboratory, Ball Aerospace, and NASA Langley Research Center has been developing a scalable solar sail configuration to address NASA s future space propulsion needs. Prior to a flight experiment of a full-scale solar sail, a comprehensive phased test plan is currently being implemented to advance the technology readiness level of the solar sail design. These tests consist of solar sail component, subsystem, and sub-scale system ground tests that simulate the vacuum and thermal conditions of the space environment. Recently, two solar sail test articles, a 7.4-m beam assembly subsystem test article and a 10-m four-quadrant solar sail system test article, were tested in vacuum conditions with a gravity-offload system to mitigate the effects of gravity. This paper presents the structural analyses simulating the ground tests and the correlation of the analyses with the test results. For programmatic risk reduction, a two-prong analysis approach was undertaken in which two separate teams independently developed computational models of the solar sail test articles using the finite element analysis software packages: NEiNastran and ABAQUS. This paper compares the pre-test and post-test analysis predictions from both software packages with the test data including load-deflection curves from static load tests, and vibration frequencies and mode shapes from structural dynamics tests. The analysis predictions were in reasonable agreement with the test data. Factors that precluded better correlation of the analyses and the tests were uncertainties in the material properties, test conditions, and modeling assumptions used in the analyses.

  13. Finite Element Analysis and Test Correlation of a 10-Meter Inflation-Deployed Solar Sail

    NASA Technical Reports Server (NTRS)

    Sleight, David W.; Michii, Yuki; Lichodziejewski, David; Derbes, Billy; Mann. Troy O.; Slade, Kara N.; Wang, John T.

    2005-01-01

    Under the direction of the NASA In-Space Propulsion Technology Office, the team of L Garde, NASA Jet Propulsion Laboratory, Ball Aerospace, and NASA Langley Research Center has been developing a scalable solar sail configuration to address NASA's future space propulsion needs. Prior to a flight experiment of a full-scale solar sail, a comprehensive phased test plan is currently being implemented to advance the technology readiness level of the solar sail design. These tests consist of solar sail component, subsystem, and sub-scale system ground tests that simulate the vacuum and thermal conditions of the space environment. Recently, two solar sail test articles, a 7.4-m beam assembly subsystem test article and a 10-m four-quadrant solar sail system test article, were tested in vacuum conditions with a gravity-offload system to mitigate the effects of gravity. This paper presents the structural analyses simulating the ground tests and the correlation of the analyses with the test results. For programmatic risk reduction, a two-prong analysis approach was undertaken in which two separate teams independently developed computational models of the solar sail test articles using the finite element analysis software packages: NEiNastran and ABAQUS. This paper compares the pre-test and post-test analysis predictions from both software packages with the test data including load-deflection curves from static load tests, and vibration frequencies and mode shapes from vibration tests. The analysis predictions were in reasonable agreement with the test data. Factors that precluded better correlation of the analyses and the tests were uncertainties in the material properties, test conditions, and modeling assumptions used in the analyses.

  14. Polestitters: Using Solar Sails for Constant Real-time Sensing of Earth's Polar Regions

    NASA Astrophysics Data System (ADS)

    Mulligan, P.; Diedrich, B. L.; Barnes, N.; Derbes, B.

    2012-12-01

    NASA has funded the Sunjammer mission - a near term demonstration of solar sail technology (2014/15). Sunjammer has the potential to demonstrate stationkeeping out of Earth's orbital plane. This is a first step in achieving "polesitter" orbits with year-round, real-time visibility of Earth's polar regions. Potential applications for such missions are illustrated. Solar sails have long been a concept for spacecraft propulsion that works by exchanging momentum with sunlight reflected by large, lightweight, mirrored sails. In addition to enabling propellantless propulsion throughout the solar system and beyond, their continuous thrust enables artificial Lagrange orbits (ALOs), some of which can be called "polesitter" orbits, with 24-hour, year-round visibility of Earth's polar regions. Several potential Earth remote sensing applications have been identified that address the limited temporal and spatial coverage from traditional polar and geostationary satellites. The Galileo spacecraft during its 1990 Earth flyby acquired imagery and radiometer data similar to the view from a polesitter. The Galileo imagery was used to derive aerosols and cloud variations used in atmospheric motion vector (AMV) derivations. Composites of satellite imagery over the South Pole is routinely used to derive atmospheric motion vectors like those performed regularly from geostationary satellites. The JAXA IKAROS mission flew a 14x14m solar sail past Venus in 2010. Sunjammer will demonstrate a state of the art 38x38m solar sail from Earth to an artificial Lagrange orbit located sunward and north of the sun-Earth L1 point. Traditional spacecraft can orbit naturally occurring Lagrange equilibrium points between the sun and Earth. The low, continuous thrust of solar sails can change where these points occur, creating new orbits with a variety of potential applications including polar remote sensing, space weather monitoring, and polar communications. This figure illustrates a selection of

  15. Application of Semi Active Control Techniques to the Damping Suppression Problem of Solar Sail Booms

    NASA Technical Reports Server (NTRS)

    Adetona, O.; Keel, L. H.; Whorton, M. S.

    2007-01-01

    Solar sails provide a propellant free form for space propulsion. These are large flat surfaces that generate thrust when they are impacted by light. When attached to a space vehicle, the thrust generated can propel the space vehicle to great distances at significant speeds. For optimal performance the sail must be kept from excessive vibration. Active control techniques can provide the best performance. However, they require an external power-source that may create significant parasitic mass to the solar sail. However, solar sails require low mass for optimal performance. Secondly, active control techniques typically require a good system model to ensure stability and performance. However, the accuracy of solar sail models validated on earth for a space environment is questionable. An alternative approach is passive vibration techniques. These do not require an external power supply, and do not destabilize the system. A third alternative is referred to as semi-active control. This approach tries to get the best of both active and passive control, while avoiding their pitfalls. In semi-active control, an active control law is designed for the system, and passive control techniques are used to implement it. As a result, no external power supply is needed so the system is not destabilize-able. Though it typically underperforms active control techniques, it has been shown to out-perform passive control approaches and can be unobtrusively installed on a solar sail boom. Motivated by this, the objective of this research is to study the suitability of a Piezoelectric (PZT) patch actuator/sensor based semi-active control system for the vibration suppression problem of solar sail booms. Accordingly, we develop a suitable mathematical and computer model for such studies and demonstrate the capabilities of the proposed approach with computer simulations.

  16. Innovative Structural Design Features for a 10 m Solar Sail Demonstrator

    NASA Technical Reports Server (NTRS)

    Laue, G.; Moore, J.; Clayton, W.

    2004-01-01

    The successful development of sail architectures will require careful attention to a number of key issues including but not limited to material strength issues, stress conditions for the membrane, load interactions between membrane and structure, and membrane material planarity. Along with the inherent challenges of fabricating and handling very large membrane structures these issues will pose real challenges for the near-term development of practical sail technologies. SRS has developed innovative technologies that deal directly with the challenges of developing very large sail membranes. Some of these technologies include edge reinforcements and innovative reinforcement attachment techniques, production of flight durable sail materials of less than 2.5 micron thicknesses and large scale fabrication techniques. SRS has employed these technologies in several large 10 m demonstrators that have been delivered to LaRC for solar vacuum testing. Details of the design of this system will be discussed.

  17. Earth orbital assessment of solar electric and solar sail propulsion systems

    NASA Technical Reports Server (NTRS)

    Teeter, R. R.

    1977-01-01

    The earth orbital applications potential of Solar Electric (Ion Drive) and Solar Sail low-thrust propulsion systems are evaluated. Emphasis is placed on mission application in the 1980s. The two low-thrust systems are compared with each other and with two chemical propulsion Shuttle upper stages (the IUS and SSUS) expected to be available in the 1980s. The results indicate limited Earth orbital application potential for the low-thrust systems in the 1980s (primarily due to cost disadvantages). The longer term potential is viewed as more promising. Of the two systems, the Ion Drive exhibits better performance and appears to have better overall application potential.

  18. The finite-element behaviour simulation of the rotary-type and frame-type solar sails on the geocentric orbits

    NASA Astrophysics Data System (ADS)

    Gorbunova, I.; Khabibullin, R.; Chernyakin, S.; Starinova, O.

    2016-04-01

    This paper discusses the research of functioning of different construction types for the spacecraft with a solar sail. Two types of the solar sail are considered, such as frame-type and rotary-type. The research is performed by means of application of the computer-assisted design system. The movement simulation of the spacecraft center mass and the forces acting on the solar sail is described. The finite element models of the two solar sail constructions are developed and compared.

  19. Electric Solar Wind Sail Kinetic Energy Impactor for Asteroid Deflection Missions

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Kouhei; Yamakawa, Hiroshi

    2016-03-01

    An electric solar wind sail uses the natural solar wind stream to produce low but continuous thrust by interacting with a number of long thin charged tethers. It allows a spacecraft to generate a thrust without consuming any reaction mass. The aim of this paper is to investigate the use of a spacecraft with such a propulsion system to deflect an asteroid with a high relative velocity away from an Earth collision trajectory. To this end, we formulate a simulation model for the electric solar wind sail. By summing thrust vectors exerted on each tether, a dynamic model which gives the relation between the thrust and sail attitude is proposed. Orbital maneuvering by fixing the sail's attitude and changing tether voltage is considered. A detailed study of the deflection of fictional asteroids, which are assumed to be identified 15 years before Earth impact, is also presented. Assuming a spacecraft characteristic acceleration of 0.5 mm/s 2, and a projectile mass of 1,000 kg, we show that the trajectory of asteroids with one million tons can be changed enough to avoid a collision with the Earth. Finally, the effectiveness of using this method of propulsion in an asteroid deflection mission is evaluated in comparison with using flat photonic solar sails.

  20. Propellantless Attitude Control of Solar Sail Technology Utilizing Reflective Control Devices

    NASA Technical Reports Server (NTRS)

    Munday, Jeremy

    2016-01-01

    Solar sails offer an opportunity for a CubeSatscale, propellant-free spacecraft technology that enables long-term and long-distance missions not possible with traditional methods. Solar sails operate using the transfer of linear momentum from photons of sunlight reflected from the surface of the sail. To propel the spacecraft, no mechanically moving parts, thrusters, or propellant are needed. However, attitude control, or orientation, is still performed using traditional methods involving reaction wheels and propellant ejection, which severely limit mission lifetime. For example, the current state of the art solutions employed by upcoming missions couple solar sails with a state of the art propellant ejection gas system. Here, the use of the gas thruster has limited the lifetime of the mission. To solve the limited mission lifetime problem, the Propellantless Attitude Control of Solar Sail Technology Utilizing Reflective Control Devices project team is working on propellantless attitude control using thin layers of material, an optical film, electrically switchable from transparent to reflective. The technology is based on a polymer-dispersed liquid crystal (PDLC), which allows this switch upon application of a voltage. This technology removes the need for propellant, which reduces weight and cost while improving performance and lifetime.

  1. Solar sail periodic orbits in the elliptic restricted three-body problem

    NASA Astrophysics Data System (ADS)

    Gong, Shengping; Li, Junfeng

    2015-02-01

    The periodic orbits of a solar sail in the elliptic restricted three-body problem are designed in this paper. The dynamical equation of a solar sail is derived in a non-uniformly rotating and pulsating coordinate frame, where out-of-plane artificial equilibria do not exist. Two families of displaced periodic orbits in the vicinity of the out-of-plane fixed points are generated by adjusting the solar sail parameters and the motion in the out-of-plane direction to satisfy the equilibrium equations. The analytical solutions to the linearized equations are obtained with average method. The stability of these orbits is studied, and the results indicate that they are always unstable. Finally, the controllability of these orbits is discussed and a typical time-varying linear quadratic regulator is used to stabilize the system.

  2. Vacuum Deployment and Testing of a 4-Quadrant Scalable Inflatable Solar Sail System

    NASA Technical Reports Server (NTRS)

    Lichodziejewski, David; Derbes, Billy; Galena, Daisy; Friese, Dave

    2005-01-01

    Solar sails reflect photons streaming from the sun and transfer momentum to the sail. The thrust, though small, is continuous and acts for the life of the mission without the need for propellant. Recent advances in materials and ultra-low mass gossamer structures have enabled a host of useful missions utilizing solar sail propulsion. The team of L'Garde, Jet Propulsion Laboratories, Ball Aerospace, and Langley Research Center, under the direction of the NASA In-Space Propulsion office, has been developing a scalable solar sail configuration to address NASA s future space propulsion needs. The baseline design currently in development and testing was optimized around the 1 AU solar sentinel mission. Featuring inflatably deployed sub-T(sub g), rigidized beam components, the 10,000 sq m sail and support structure weighs only 47.5 kg, including margin, yielding an areal density of 4.8 g/sq m. Striped sail architecture, net/membrane sail design, and L'Garde's conical boom deployment technique allows scalability without high mass penalties. This same structural concept can be scaled to meet and exceed the requirements of a number of other useful NASA missions. This paper discusses the interim accomplishments of phase 3 of a 3-phase NASA program to advance the technology readiness level (TRL) of the solar sail system from 3 toward a technology readiness level of 6 in 2005. Under earlier phases of the program many test articles have been fabricated and tested successfully. Most notably an unprecedented 4-quadrant 10 m solar sail ground test article was fabricated, subjected to launch environment tests, and was successfully deployed under simulated space conditions at NASA Plum Brook s 30m vacuum facility. Phase 2 of the program has seen much development and testing of this design validating assumptions, mass estimates, and predicted mission scalability. Under Phase 3 a much larger 20 m square test article including subscale vane has been fabricated and tested. A 20 m system

  3. An analysis of the orbital Evolution of a solar sail around Mercury

    NASA Astrophysics Data System (ADS)

    Vilhena de Moraes, Rodolpho; Prado, Antonio; Carvalho, Jean Paulo; Treasaco, Eva

    2016-07-01

    Solar sails are a new concept of spacecraft propulsion that uses solar radiation pressure to generate acceleration: this way the sail experiences a small but unlimited and continuous acceleration. This work presents a method for finding initial conditions for frozen orbits for a solar sail around Mercury Frozen orbits are those whose orbital elements remain constant on average. Thus, at a given latitude, the satellite always passes at the same altitude. The orbital dynamics of the solar sail is governed by the potential attraction of the main body and the Sun. Besides the J2, J3 and C22 of Mercury gravity field, the dynamical model also includes the eccentricity and inclination of the orbit of the third body (Sun) and the solar acceleration pressure. In order to remove short-period terms of the dynamical system, a double averaging technique is applied to the disturbig potential. This algorithm is a two-fold process which firstly averages over the period of the satellite and secondly averages with respect to the period of the third body. The double-averaged potential is introduced in the Lagrange Planetary equations. Thus, frozen orbits are characterized by a surface depending on three variables: the orbital semi-major axis, eccentricity and inclination. These surfaces determine orbits ranging in altitude from 300 to 1000 km, which include the altitude values considered in future scientific missions around Mercury such as BepiColombo. Finally, this work delves into the influence on the dynamics of the spacecraft for different values of the sail area-to-mass ratio, which is a parameter related to the efficiency of the solar sail Sponsored by CNPq - Brazil. The author is grateful to CNPq- Brazil for contract 306953/2014-5.

  4. Proximal Blade Twist Feedback Control for Heliogyro Solar Sails

    NASA Astrophysics Data System (ADS)

    Smith, Sarah Mitchell

    A heliogyro spacecraft is a specific type of solar sail that generates thrust from the reflection of solar photons. It consists of multiple long (200 to 600 meters), thin blades, similar to a helicopter. The heliogyro's blades remain in tension by spinning around the central hub of the spacecraft. The individual blades are pitched collectively or cyclically to produce the desired maneuver profile. The propellant-free heliogyro is a long-duration sustainable spacecraft whose maneuverability allows it to attain previously inaccessible orbits for traditional spacecraft. The blades are constructed from thin Mylar sheets, approximately 2.5 ?m thick, which have very little inherent damping making it necessary to include some other way of attenuating blade vibration caused by maneuvering. The most common approach is to incorporate damping through the root pitch actuator. However, due to the small root pitch control torques required, on the order of 2 ?Nm, compared to the large friction torques associated with a root pitch actuator, it is challenging to design a root control system that takes friction into account and can still add damping to the blade. The purpose of this research is to address the limitations of current control designs for a heliogyro spacecraft and to develop a physically realizable root pitch controller that effectively damps the torsional structural modes of a single heliogyro blade. Classical control theory in conjunction with impedance control techniques are used to design a position-source root pitch controller to dominate friction with high gains, wrapped with an outer loop that adds damping to the blade by sensing differential twist outboard of the blade root. First, modal parameter characterization experiments were performed on a small-scale heliogyro blade in a high vacuum chamber to determine a damping constant to be used in the membrane ladder finite element model of the blade. The experimental damping ratio of the lowest frequency torsional

  5. Solar Sailing Kinetic Energy Interceptor (KEI) Mission for Impacting/Deflecting Near-Earth Asteroids

    NASA Technical Reports Server (NTRS)

    Wie, Bong

    2005-01-01

    A solar sailing mission architecture, which requires a t least ten 160-m, 300-kg solar sail spacecraft with a characteristic acceleration of 0.5 mm/sqs, is proposed as a realistic near- term option for mitigating the threat posed by near-Earth asteroids (NEAs). Its mission feasibility is demonstrated for a fictional asteroid mitigation problem created by AIAA. This problem assumes that a 200-m asteroid, designated 2004WR, was detected on July 4, 2004, and that the expected impact will occur on January 14, 2015. The solar sailing phase of the proposed mission for the AIAA asteroid mitigation problem is comprised of the initial cruise phase from 1 AU t o 0.25 AU (1.5 years), the cranking orbit phase (3.5 years), and the retrograde orbit phase (1 year) prior to impacting the target asteroid at its perihelion (0.75 AU from the sun) on January 1, 2012. The proposed mission will require at least ten kinetic energy interceptor (KEI) solar sail spacecraft. Each KEI sailcraft consists of a 160- m, 150-kg solar sail and a 150-kg microsatellite impactor. The impactor is to be separated from a large solar sail prior to impacting the 200-m target asteroid at its perihelion. Each 150-kg microsatellite impactor, with a relative impact velocity of at least 70 km/s, will cause a conservatively estimated AV of 0.3 cm/s in the trajectory of the 200-m target asteroid, due largely to the impulsive effect of material ejected from the newly-formed crater. The deflection caused by a single impactor will increase the Earth-miss-distance by 0.45Re (where Re denotes the Earth radius of 6,378 km). Therefore, at least ten KEI sailcraft will be required for consecutive impacts, but probably without causing fragmentation, to increase the total Earth-miss-distance by 4.5Re. This miss-distance increase of 29,000 km is outside of a typical uncertainty/error of about 10,000 km in predicting the Earth-miss- distance. A conventional Delta I1 2925 launch vehicle is capable of injecting at least two KEI

  6. Towing Asteroids with Gravity Tractors Enhanced by Tethers and Solar Sails

    NASA Technical Reports Server (NTRS)

    Shen, Haijun; Roithmayr, Carlos M.

    2015-01-01

    Material collected from an asteroid's surface can be used to increase gravitational attraction between the asteroid and a Gravity Tractor (GT); the spacecraft therefore operates more effectively and is referred to as an Enhanced Gravity Tractor (EGT). The use of tethers and solar sails to further improve effectiveness and simplify operations is investigated. By employing a tether, the asteroidal material can be placed close to the asteroid while the spacecraft is stationed farther away, resulting in a better safety margin and improved thruster efficiency. A solar sail on a spacecraft can naturally provide radial offset and inter-spacecraft separation required for multiple EGTs.

  7. Modeling the Multi-Body System Dynamics of a Flexible Solar Sail Spacecraft

    NASA Technical Reports Server (NTRS)

    Kim, Young; Stough, Robert; Whorton, Mark

    2005-01-01

    Solar sail propulsion systems enable a wide range of space missions that are not feasible with current propulsion technology. Hardware concepts and analytical methods have matured through ground development to the point that a flight validation mission is now realizable. Much attention has been given to modeling the structural dynamics of the constituent elements, but to date an integrated system level dynamics analysis has been lacking. Using a multi-body dynamics and control analysis tool called TREETOPS, the coupled dynamics of the sailcraft bus, sail membranes, flexible booms, and control system sensors and actuators of a representative solar sail spacecraft are investigated to assess system level dynamics and control issues. With this tool, scaling issues and parametric trade studies can be performed to study achievable performance, control authority requirements, and control/structure interaction assessments.

  8. Deployment dynamics of a simplified spinning IKAROS solar sail via absolute coordinate based method

    NASA Astrophysics Data System (ADS)

    Zhao, Jiang; Tian, Qiang; Hu, Hai-Yan

    2013-02-01

    The spinning solar sail of large scale has been well developed in recent years. Such a solar sail can be considered as a rigid-flexible multibody system mainly composed of a spinning central rigid hub, a number of flexible thin tethers, sail membranes, and tip masses. A simplified interplanetary kite-craft accelerated by radiation of the Sun (IKAROS) model is established in this study by using the absolute-coordinate-based (ACB) method that combines the natural coordinate formulation (NCF) describing the central rigid hub and the absolute nodal coordinate formulation (ANCF) describing flexible parts. The initial configuration of the system in the second-stage deployment is determined through both dynamic and static analyses. The huge set of stiff equations of system dynamics is solved by using the generalized-alpha method, and thus the deployment dynamics of the system can be well understood.

  9. Photogrammetry and Videogrammetry Methods for Solar Sails and Other Gossamer Structures

    NASA Technical Reports Server (NTRS)

    Black, Jonathan T.; Pappa, Richard S.

    2004-01-01

    Ultra-lightweight and inflatable gossamer space structures are designed to be tightly packaged for launch, then deploy or inflate once in space. These properties will allow for in-space construction of very large structures 10 to 1000 meters in size such as solar sails, inflatable antennae, and space solar power stations using a single launch. Solar sails are of particular interest because of their potential for propellantless propulsion. Gossamer structures do, however, have significant complications. Their low mass and high flexibility make them very difficult to test on the ground. The added mass and stiffness of attached measurement devices can significantly alter the static and dynamic properties of the structure. This complication necessitates an alternative approach for characterization. This paper discusses the development and application of photogrammetry and videogrammetry methods for the static and dynamic characterization of gossamer structures, as four specific solar sail applications demonstrate. The applications prove that high-resolution, full-field, non-contact static measurements of solar sails using dot projection photogrammetry are possible as well as full-field, noncontact, dynamic characterization using dot projection videogrammetry.

  10. The Development of Solar Sail Propulsion for NASA Science Missions to the Inner Solar System

    NASA Technical Reports Server (NTRS)

    Montgomery, Edward E, IV; Johnson, Charles Les

    2004-01-01

    This paper examines recent assessments of the technology challenges facing solar sails, identifies the systems and technologies needing development, and the approach employed by NASA's In-space Propulsion Program in NASA to achieve near term products that move this important technology from low technology readiness level (TRL) toward the goal of application to science missions in near earth space and beyond. The status of on-going efforts to design, build, and test ground demonstrators of alternate approaches to structures (inflatable versus rigid), membrane materials, optical shape sensing, and attitude control will be presented along with planned future investments.

  11. Formation control of multi-robots for on-orbit assembly of large solar sails

    NASA Astrophysics Data System (ADS)

    Hu, Quan; Zhang, Yao; Zhang, Jingrui; Hu, Haiyan

    2016-06-01

    This study focuses on the formation control of four robots used for the on-orbit construction of a large solar sail. The solar sail under consideration is non-spinning and has a 1 km2 area. It includes a hub as the central body and four large booms supporting the lightweight films. Four formation operating space robots capable of walking on the boom structure are utilized to deploy the sail films. Because of the large size and mass of the sail, the robots should remain in formation during the sail deployment to avoid dramatic changes in the system properties. In this paper, the formation control issue of the four robots is solved by an adaptive sliding mode controller. A disturbance observer with finite-time convergence is embedded to improve the control performance. The proposed controller is capable of resisting the strong uncertainties in the operation and do not require the accurate parameters of the system. The stability is proven, and numerical simulations are provided to validate the effectiveness of the control strategy.

  12. The role of solar sails in the investigation and exploration of Mars

    NASA Technical Reports Server (NTRS)

    Krivenchenko, Eugene

    1989-01-01

    One of the projects designed by the Student Space Design Bureau (ISKRA) of the Moscow Aviation Institute (MAI) is a space vehicle equipped with solar sails for stabilization and orientation control and, partly, as a propulsion unit. This report is a summary of work done on this project.

  13. Solar Power Sail, the Jovian Trojan Explorer and Deep Space Astronomical Platform

    NASA Astrophysics Data System (ADS)

    Yano, H.; Mori, O.; Funase, R.; Matsuura, S.; Fujimoto, M.; Takashima, T.; Solar Power Sail/Jovian Trojan Working Group

    2012-05-01

    Solar Power Sail is an engineering verification spacecraft for Jupiter and Trojan exploration and deep space astronomical platform during its long cruising period in the early 2020's. It is hoped to co-ordinate observations of Jupiter with the EJSM spacecraft fleet.

  14. AOCS Performance and Stability Validation for a 160-m Solar Sail with Control-Structure Interactions

    NASA Technical Reports Server (NTRS)

    Wie, Bong; Murphy, David

    2005-01-01

    Future solar sail missions, such as NASA's Solar Polar Imager Vision, will require sails with dimensions on the order of 50-500 m. We are examining a square sail design with moving mass (trim control mass, TCM) and quadrant rotation primary actuators plus pulsed plasma thrusters (PPTs) at the mast tips for backup attitude control. Quadrant rotation is achieved via roll stabilizer bars (RSB) at the mast tips. At these sizes, given the gossamer nature of the sail supporting structures, flexible modes may be low enough to interact with the control system, especially as these actuators are located on the flexible structure itself and not on the rigid core. This paper develops a practical analysis of the flexible interactions using state-space systems and modal data from finite element models of the system. Torsion and bending of the masts during maneuvers could significantly affect the function of the actuators while activation of the membrane modes could adversely affect the thrust vector direction and magnitude. Analysis of the RSB and TCM dynamics for developing high-fidelity simulations is included. For control analysis of the flexible system, standard finite-element models of the flexible sail body are loaded and the modal data is used to create a modal coordinate state-space system. Key parameters include which modes to include, which nodes are of interest for force inputs and displacement outputs, connecting nodes through which external forces and torques are applied from the flex body to the core, any nominal momentum in the system, and any steady rates. The system is linearized about the nominal attitude and rate. The state-space plant can then be analyzed with a state-space controller, and Bode, Nyquist, step and impulse responses generated. The approach is general for any rigid core with a flexible appendage. This paper develops a compensator for a simple two-mass flex system and extrapolates the results to the solar sail. A finite element model of the 20 m

  15. The Solar-Sail Launched Interstellar Probe: Pre-Perihelion Trajectories and Application of Holography

    NASA Technical Reports Server (NTRS)

    Matloff, Gregory L.

    2002-01-01

    Design of missions beyond our solar system presents many challenges. Here, we consider certain aspects of the solar-sail launched interstellar probe (ISP), a spacecraft slated for launch in the 2010 time period that is planned to reach the heliopause, at 200 Astronomical Units (AU) from the Sun after a flight of about 20-years duration. The baseline mission under consideration by NASA / JPL has a sail radius of 200 m, a science payload of 25 kg, a spacecraft areal mass thickness of about two grams per square meter and is accelerated out of the solar system at about 14 AU per year after performing a perihelion pass of about 0.25 AU. In current plans, the sail is to be dropped near Jupiter's orbit (5.2 AU from the Sun) on the outbound trajectory leg. One aspect of this study is application of a realistic model of sail thermo-optics to sail kinematics that includes diffuse / specular reflectance and sail roughness. The effects of solar-wind degradation of sail material, based on recent measurements at the NASA MSFC (Marshall Space Flight Center) Space Environment Facility were incorporated in the kinematical model. After setting initial and final conditions for the spacecraft, trajectory was optimized using the provision of variable sail aspect angle. The second phase of the study included consideration of rainbow holography as a medium for a message plaque that would be carried aboard the ISP in the spirit of the message plaques aboard Pioneer 10 /11 and Voyager 1 /2. A prototype holographic message plaque was designed and created by artist C. Bangs with the assistance of Ana Maria Nicholson and Dan Schweitzer of the Center for Holographic Arts in Long Island City, NY. The piece was framed by Simon Liu Inc. of Brooklyn, NY. Concurrent to the creation of the prototype message plaque, we explored the potential of this medium to transmit large amounts of visual information to any extraterrestrial civilization that might detect and intercept ISP. It was also necessary to

  16. Displaced orbits generated by solar sails for the hyperbolic and degenerated cases

    NASA Astrophysics Data System (ADS)

    Xu, Ming; Xu, Shi-Jie

    2012-02-01

    Displaced non-Keplerian orbits above planetary bodies can be achieved by orientating the solar sail normal to the sun line. The dynamical systems techniques are employed to analyze the nonlinear dynamics of a displaced orbit and different topologies of equilibria are yielded from the basic configurations of Hill's region, which have a saddle-node bifurcation point at the degenerated case. The solar sail near hyperbolic or degenerated equilibrium is quite unstable. Therefore, a controller preserving Hamiltonian structure is presented to stabilize the solar sail near hyperbolic or degenerated equilibrium, and to generate the stable Lissajous orbits that stay stable inside the stabilizing region of the controller. The main contribution of this paper is that the controller preserving Hamiltonian structure not only changes the instability of the equilibrium, but also makes the modified elliptic equilibrium become unique for the controlled system. The allocation law of the controller on the sail's attitude and lightness number is obtained, which verifies that the controller is realizable.

  17. Solar Sail - Fresnel Zone Plate Lens for a Large Space Based Telescope

    SciTech Connect

    Early, J T

    2002-02-13

    A Fresnel zone plate lens made with solar sail material could be used as the primary optic for a very large aperture telescope on deep space probes propelled by solar sails. The large aperture telescope capability could enable significant science on fly-by missions to the asteroids, Pluto, Kuiper belt or the tort cloud and could also enable meaningful interstellar fly-by missions for laser propelled sails. This type of lens may also have some potential for laser communications and as a solar concentrator. The techniques for fabrication of meter size and larger Fresnel phase plate optics are under development at LLNL, and we are extending this technology to amplitude zone plates made from sail materials. Corrector optics to greatly extend the bandwidth of these Fresnel optics will be demonstrated in the future. This novel telescope concept will require new understanding of the fabrication, deployment and control of gossamer space structures. It will also require new materials technology for fabricating these optics and understanding their long term stability in a space environment.

  18. Rendezvous, Landing and Sample Return Mission to Jupiter Trojans by the Solar Power Sail

    NASA Astrophysics Data System (ADS)

    Yano, Hajime; Matsuura, Shuji; Mori, Osamu; Yonetoku, Daisuke; Nakamura, Ryosuke; Sekine, Yasuhito; Abe, Shinsuke

    JAXA/ISAS has been preparing for the Solar Power Sail mission, Japan’s first outer planet region exploration. Its precursor was successfully realized by IKAROS, the world's first deep space solar sail spacecraft, in 2010 between the Earth and Venus orbits. The Solar Power Sail is defined primarily as a technology demonstration mission; yet it will also present game-changing opportunities for both space astronomy and solar system exploration. The former will benefit the cruising operation, which will enable ”dust free” infrared astronomy beyond the cocoon of the zodiacal light to search for the first generation light of the Universe. Interplanetary-long baseline will allow gamma-ray burst observation to identify their source locations much more precise than ever. As for solar system exploration, the Solar Power Sail, which is not depended upon RTG technology, will offer the world's first possibility of rendezvous, landing and sample return from the outer planet region, i.e., in the Jupiter region and beyond. With this technology, we are aiming to visit Jupiter Trojan asteroids, one of the last uncharted frontiers of the Solar System. Jupiter Trojans may hold fundamental clues of the Solar System formation and revolution discussed by two competing hypotheses between the classic model and the planetary migration model. The former suggests that Trojan asteroids are mainly survivors of building blocks of the Jupiter system, while the latter claims that they must be intruders from outer regions after the planetary migration of gas planets settled. This paper outlines scientific objectives of Jupiter Trojan exploration, its mission design and major aspects of the spacecraft system, nature of candidate target asteroids, in-situ observation and lander instruments including optical camera, imaging spectrometer, high-resolution TOF mass spectrometer, and large-area dust counter, together with a strategy of the sample return option from the surface of a Trojan asteroid.

  19. Study of a 30-M Boom For Solar Sail-Craft: Model Extendibility and Control Strategy

    NASA Technical Reports Server (NTRS)

    Keel, Leehyun

    2005-01-01

    Space travel propelled by solar sails is motivated by the fact that the momentum exchange that occurs when photons are reflected and/or absorbed by a large solar sail generates a small but constant acceleration. This acceleration can induce a constant thrust in very large sails that is sufficient to maintain a polar observing satellite in a constant position relative to the Sun or Earth. For long distance propulsion, square sails (with side length greater than 150 meters) can reach Jupiter in two years and Pluto in less than ten years. Converting such design concepts to real-world systems will require accurate analytical models and model parameters. This requires extensive structural dynamics tests. However, the low mass and high flexibility of large and light weight structures such as solar sails makes them unsuitable for ground testing. As a result, validating analytical models is an extremely difficult problem. On the other hand, a fundamental question can be asked. That is whether an analytical model that represents a small-scale version of a solar-sail boom can be extended to much larger versions of the same boom. To answer this question, we considered a long deployable boom that will be used to support the solar sails of the sail-craft. The length of fully deployed booms of the actual solar sail-craft will exceed 100 meters. However, the test-bed we used in our study is a 30 meter retractable boom at MSFC. We first develop analytical models based on Lagrange s equations and the standard Euler-Bernoulli beam. Then the response of the models will be compared with test data of the 30 meter boom at various deployed lengths. For this stage of study, our analysis was limited to experimental data obtained at 12ft and 18ft deployment lengths. The comparison results are positive but speculative. To observe properly validate the analytic model, experiments at longer deployment lengths, up to the full 30 meter, have been requested. We expect the study to answer the

  20. Performance quantification of heliogyro solar sails using structural, attitude, and orbital dynamics and control analysis

    NASA Astrophysics Data System (ADS)

    Guerrant, Daniel Vernon

    Solar sails enable or enhance exploration of a variety of destinations both within and without the solar system. The heliogyro solar sail architecture divides the sail into blades spun about a central hub and centrifugally stiffened. The resulting structural mass savings can often double acceleration verses kite-type square sails of the same mass. Pitching the blades collectively and cyclically, similar to a helicopter, creates attitude control moments and vectors thrust. The principal hurdle preventing heliogyros' implementation is the uncertainty in their dynamics. This thesis investigates attitude, orbital and structural control using a combination of analytical studies and simulations. Furthermore, it quantifies the heliogyro's ability to create attitude control moments, change the thrust direction, and stably actuate blade pitch. This provides engineers a toolbox from which to estimate the heliogyro's performance and perform trades during preliminary mission design. It is shown that heliogyros can create an attitude control moment in any direction from any orientation. While their large angular momentum limits attitude slewing to only a few degrees per hour, cyclic blade pitching can slew the thrust vector within a few minutes. This approach is only 13% less efficient than slewing a square sail during Earth escape, so it does not offset the overall acceleration benefits of heliogyros. Lastly, a root pitch motor should be able to settle torsional disturbances within a few rotations and achieve thrust performance comparable to that of flat blades. This work found no significant dynamic hurdles for heliogyros, and it provides key insight into their practical capabilities and limitations for future mission designers.

  1. Elements of solar sail navigation with application to a Halley's comet rendezvous

    NASA Technical Reports Server (NTRS)

    Jacobson, R. A.; Thornton, C. L.

    1978-01-01

    The problem of interplanetary navigation of a solar sail spacecraft is examined and found to be analogous to that of solar electric spacecraft. The dominant navigation error sources are shown to be accelerations that are unaccounted for in the description of the vehicle's motion, due to the inability to precisely model the solar radiation pressure. A strategy for navigation in the presence of these accelerations is devised, based on techniques previously developed for solar electric vehicles. An evaluation of the strategy is made for a Halley's comet rendezvous mission, and the results of that evaluation indicate that the strategy gives acceptable performance.

  2. Periodic and quasi-periodic motions of a solar sail close to SL 1 in the Earth-Sun system

    NASA Astrophysics Data System (ADS)

    Farrés, Ariadna; Jorba, Àngel

    2010-06-01

    Solar sails are a proposed form of spacecraft propulsion using large membrane mirrors to propel a satellite taking advantage of the solar radiation pressure. To model the dynamics of a solar sail we have considered the Earth-Sun Restricted Three Body Problem including the Solar radiation pressure (RTBPS). This model has a 2D surface of equilibrium points parametrised by the two angles that define the sail orientation. In this paper we study the non-linear dynamics close to an equilibrium point, with special interest in the bounded motion. We focus on the region of equilibria close to SL 1, a collinear equilibrium point that lies between the Earth and the Sun when the sail is perpendicular to the Sun-sail direction. For different fixed sail orientations we find families of planar, vertical and Halo-type orbits. We have also computed the centre manifold around different equilibria and used it to describe the quasi-periodic motion around them. We also show how the geometry of the phase space varies with the sail orientation. These kind of studies can be very useful for future mission applications.

  3. In-Vacuum Photogrammetry of a Ten-Meter Square Solar Sail

    NASA Technical Reports Server (NTRS)

    Pappa, Richard S.; Jones, Thomas W.; Lunsford, Charles B.; Meyer, Christopher G.

    2006-01-01

    Solar sailing is a promising, future in-space propulsion method that uses the small force of reflecting sunlight to accelerate a large, reflective membrane without expendable propellants. One of two solar sail configurations under development by NASA is a striped net approach by L'Garde, Inc. This design uses four inflatably deployed, lightweight booms supporting a network of thin strings onto which four quadrants of ultrathin aluminized membranes are attached. The NASA Langley Research Center (LaRC) provided both experimental and analytical support to L'Garde for validating the structural characteristics of this unique, ultralightweight spacecraft concept. One of LaRC's responsibilities was to develop and apply photogrammetric methods to measure sail shape. The deployed shape provides important information for validating the accuracy of finite-element modeling techniques. Photogrammetry is the science and art of calculating 3D coordinates of targets or other distinguishing features on structures using images. A minimum of two camera views of each target is required for 3D determination, but having four or more camera views is preferable for improved reliability and accuracy. Using retroreflective circular targets typically provides the highest measurement accuracy and automation. References 3 and 4 provide details of photogrammetry technology, and reference 5 discusses previous experiences with photogrammetry for measuring gossamer spacecraft structures such as solar sails. This paper discusses the experimental techniques used to measure a L Garde 10-m solar sail test in vacuum with photogrammetry. The test was conducted at the NASA-Glenn Space Power Facility (SPF) located at Plum Brook Station in Sandusky, Ohio. The SPF is the largest vacuum chamber in the United States, measuring 30 m in diameter by 37 m in height. High vacuum levels (10(exp -6) torr) can be maintained inside the chamber, and cold environments (-195 C) are possible using variable

  4. Influence of attitude control on transfer mission for a flexible solar sail

    NASA Astrophysics Data System (ADS)

    Jin, Zhang; Tianshu, Wang; Shengping, Gong

    2014-04-01

    A solar-photon sail space vehicle, or a sailcraft, is a new type of vehicle apt also for deep-space exploration. A sailcraft is pushed by the pressure of the solar irradiance on the sail. The sailcraft has large and highly flexible structure, and its motion involves a coupling of the orbit, the attitude and structural vibration. Based on the coupling effect of the orbit and the attitude, the theory of time-optimal control is used to design the transfer trajectory from an earth-centric orbit to a heliocentric polar orbit. This paper establishes the reduced dynamic model for a flexible solar sail with foreshortening deformation and coupling of its attitude and vibration. In the process of attitude control, the sailcraft will generate orbital deviations from the designed orbit as well as structural vibration. This is especially true when the sailcraft makes large-angle maneuvers: larger orbital deviations and structural vibrations are generated. When initial deviations and solar pressure disturbance torques are considered, the process of attitude control leads to greater accumulated error in the transfer trajectory, which demonstrates that the process of attitude control is important to the sailcraft mission.

  5. Recent Advances in Heliogyro Solar Sail Structural Dynamics, Stability, and Control Research

    NASA Technical Reports Server (NTRS)

    Wilkie, W. Keats; Warren, Jerry E.; Horta, Lucas G.; Lyle, Karen H.; Juang, Jer-Nan; Gibbs, S. Chad; Dowell, Earl H.; Guerrant, Daniel V.; Lawrence, Dale

    2015-01-01

    Results from recent NASA sponsored research on the structural dynamics, stability, and control characteristics of heliogyro solar sails are summarized. Specific areas under investigation include coupled nonlinear finite element analysis of heliogyro membrane blade with solar radiation pressure effects, system identification of spinning membrane structures, and solarelastic stability analysis of heliogyro solar sails, including stability during blade deployment. Recent results from terrestrial 1-g blade dynamics and control experiments on "rope ladder" membrane blade analogs, and small-scale in vacuo system identification experiments with hanging and spinning high-aspect ratio membranes will also be presented. A low-cost, rideshare payload heliogyro technology demonstration mission concept is used as a mission context for these heliogyro structural dynamics and solarelasticity investigations, and is also described. Blade torsional dynamic response and control are also shown to be significantly improved through the use of edge stiffening structural features or inclusion of modest tip masses to increase centrifugal stiffening of the blade structure. An output-only system identification procedure suitable for on-orbit blade dynamics investigations is also developed and validated using ground tests of spinning sub-scale heliogyro blade models. Overall, analytical and experimental investigations to date indicate no intractable stability or control issues for the heliogyro solar sail concept.

  6. Jovian Trojan Exploration and Deep Space Cruising Sciences by the Solar Power Sail

    NASA Astrophysics Data System (ADS)

    Yano, Hajime

    2012-07-01

    Jovian Trojan asteroids are as one of a few remaining final frontiers within our Solar System, which may hold fundamental clues of the Solar System formation and revolution. Their genesis is discussed by two competing hypotheses between the classic model and the more recent Nice model. The former suggests that Trojan asteroids are mainly survivors of building blocks of the Jupiter system, while the latter claims that they must be intruders from outer regions after the planetary migration of gas planets settled. In previous years, scientific investigations of these dark, distant asteroid reservoirs were largely depended upon ground observations by large optical and spectroscopic telescopes, while few D-type asteroid analog meteorites were collected on the earth with an exception of Tagish Lake meteorites. However, thanks to recent development of observational technologies such as adaptive optics, statistical studies of asteroids in Jovian L4 and L5 regions have been made possible and raised new questions about their compositions far beyond the current snow line and internal structures implied by binary system measurements. This presentation discusses major scientific objectives of an exploration mission to Jovian Trojans for the first time in the history, its mission design and spacecraft system using solar power sail, a hybrid propulsion system of electric propulsion and photon sail, which inherited from the IKAROS deep space solar sail spacecraft, together with major engineering challenges, in-situ observation instruments and operational options.

  7. MODEL CORRELATION STUDY OF A RETRACTABLE BOOM FOR A SOLAR SAIL SPACECRAFT

    NASA Technical Reports Server (NTRS)

    Adetona, O.; Keel, L. H.; Oakley, J. D.; Kappus, K.; Whorton, M. S.; Kim, Y. K.; Rakpczy, J. M.

    2005-01-01

    To realize design concepts, predict dynamic behavior and develop appropriate control strategies for high performance operation of a solar-sail spacecraft, we developed a simple analytical model that represents dynamic behavior of spacecraft with various sizes. Since motion of the vehicle is dominated by retractable booms that support the structure, our study concentrates on developing and validating a dynamic model of a long retractable boom. Extensive tests with various configurations were conducted for the 30 Meter, light-weight, retractable, lattice boom at NASA MSFC that is structurally and dynamically similar to those of a solar-sail spacecraft currently under construction. Experimental data were then compared with the corresponding response of the analytical model. Though mixed results were obtained, the analytical model emulates several key characteristics of the boom. The paper concludes with a detailed discussion of issues observed during the study.

  8. Photogrammetry and Videogrammetry Methods Development for Solar Sail Structures. Masters Thesis awarded by George Washington Univ.

    NASA Technical Reports Server (NTRS)

    Pappa, Richard S. (Technical Monitor); Black, Jonathan T.

    2003-01-01

    This report discusses the development and application of metrology methods called photogrammetry and videogrammetry that make accurate measurements from photographs. These methods have been adapted for the static and dynamic characterization of gossamer structures, as four specific solar sail applications demonstrate. The applications prove that high-resolution, full-field, non-contact static measurements of solar sails using dot projection photogrammetry are possible as well as full-field, non-contact, dynamic characterization using dot projection videogrammetry. The accuracy of the measurement of the resonant frequencies and operating deflection shapes that were extracted surpassed expectations. While other non-contact measurement methods exist, they are not full-field and require significantly more time to take data.

  9. Switch programming of reflectivity control devices for the coupled dynamics of a solar sail

    NASA Astrophysics Data System (ADS)

    Hu, Tianjian; Gong, Shengping; Mu, Junshan; Li, Junfeng; Wang, Tianshu; Qian, Weiping

    2016-03-01

    As demonstrated in the Interplanetary Kite-craft Accelerated by Radiation Of the Sun (IKAROS), reflectivity control devices (RCDs) are switched on or off independently with each other, which has nevertheless been ignored by many previous researches. This paper emphasizes the discrete property of RCDs, and aims to obtain an appropriate switch law of RCDs for a rigid spinning solar sail. First, the coupled attitude-orbit dynamics is derived from the basic solar force and torque model into an underdetermined linear system with a binary set constraint. Subsequently, the coupled dynamics is reformulated into a constrained quadratic programming and a basic gradient projection method is designed to search for the optimal solution. Finally, a circular sail flying in the Venus rendezvous mission demonstrates the model and method numerically, which illustrates approximately 103 km terminal position error and 0.5 m/s terminal velocity error as 80 independent RCDs are switched on or off appropriately.

  10. Investigation of Structural Dynamics in a 2-Meter Square Solar Sail Model Including Axial Load Effects

    NASA Technical Reports Server (NTRS)

    Holland, D. B.; Virgin, L. N.; Belvin, W. K.

    2003-01-01

    This paper presents a parameter study of the effect of boom axial loading on the global dynamics of a 2-meter solar sail scale model. The experimental model used is meant for building expertise in finite element analysis and experimental execution, not as a predecessor to any planned flight mission or particular design concept. The results here are to demonstrate the ability to predict and measure structural dynamics and mode shapes in the presence of axial loading.

  11. The dynamics and control of solar-sail spacecraft in displaced lunar orbits

    NASA Astrophysics Data System (ADS)

    Wawrzyniak, Geoffrey George

    Trajectory generation for any spacecraft mission application typically involves either well-developed analytical approximations or a linearization with respect to a known solution. Such approximations are based on the well-understood dynamics of behavior in the system. However, when two or more large bodies (e.g., the Earth and the Moon or the Sun, the Earth and the Moon) are present, trajectories in the multi-body gravitational field can evolve chaotically. The problem is further complicated when an additional force from a solar sail is included. Solar sail trajectories are often developed in a Sun-centered reference frame in which the sunlight direction is fixed. New challenges arise when modeling a solar-sail trajectory in a reference frame attached to the Earth and the Moon (a frame that rotates in inertial space). Advantages accrue from geometry and symmetry properties that are available in this Earth--Moon reference frame, but the Sun location and the sunlight direction change with time. Current trajectory design tools can reveal many solutions within these regimes. Recent work using numerical boundary value problem (BVP) solvers has demonstrated great promise for uncovering additional and, sometimes, "better" solutions to problems in spacecraft trajectory design involving solar sails. One such approach to solving BVPs is the finite-difference method. Derivatives that appear in the differential equations are replaced with their respective finite differences and evaluated at node points along the trajectory. The solution process is iterative. A candidate solution, such as an offset circle or a point, is discretized into nodes, and the equations that represent the relationships at the nodes are solved simultaneously. Finite-difference methods (FDMs) exploit coarse initial approximations and, with the system constraints (such as the continuous visibility of the spacecraft from a point on the lunar surface), to develop orbital solutions in regions where the

  12. MicroPPT-Based Secondary/Backup ACS for a 160-m, 450-kg Solar Sail Spacecraft

    NASA Technical Reports Server (NTRS)

    Wie, Bong; Murphy, David

    2005-01-01

    Solar sail tip-mounted, lightweight pulsed plasma thrusters (PPTs) are proposed for a secondary (or backup) attitude control system (ACS) of a 160-m, 450-kg solar sail spacecraft of the Solar Polar Imager (SPI) mission. A propellantless primary ACS of the SPI sailcraft employs trim control masses running along mast lanyards for pitch/yaw control together with roll stabilizer bars at the mast tips for quadrant tilt (roll) control. The robustness of such a propellantless primary ACS would be further enhanced by a secondary ACS utilizing tip-mounted, lightweight PPTs. The microPPT-based ACS is intended mainly for attitude recovery maneuvers from various off-nominal conditions that cannot be reliably handled by the propellantless primary ACS. However, it can also be employed for: i) the checkout or standby mode prior to and during sail deployment, ii) the post-deployment transition mode (prior to the propellantless primary ACS mode operation), iii) the solar sailing cruise mode of a trimmed sailcraft, and iv) the spin-stabilized, sun-pointing, safe mode. Although a conventional bus ACS is required for the SPI mission as the sail is jettisoned at the start of its science mission phase, the microPPT-based ACS option promises greater redundancy and robustness for the SPI mission. For other sailing missions, where the sail is never jettisoned, this secondary ACS provides a lower-cost, lower-mass propulsion for deployment control and greater redundancy than any traditional reaction-jet control system. This paper presents an overview nf the state--of-the--art microPPT technology, the design requirements of microPPTs for solar sail attitude control, and the preliminary ACS design and simulation results.

  13. Three-dimensional time optimal double angular momentum reversal trajectory using solar sails

    NASA Astrophysics Data System (ADS)

    Zeng, Xiangyuan; Baoyin, Hexi; Li, Junfeng; Gong, Shengping

    2011-12-01

    A new concept of three dimensional non-Keplerian trajectories with double angular momentum reversal is investigated with high performance solar sails. The main discussion of this paper is about such 3D solar inverse orbits with inner constraints. The problem is addressed in a time optimal control framework solved by an indirect method. Two typical solar inverse orbits have been achieved and presented in a 3D non-dimensional dynamic model in the Heliocentric Inertial Frame. Starting from the Earth orbit ecliptic plane, a sailcraft in the inverse orbit exhibits a butterfly shape trajectory. As such, the new orbits are symmetrical with respect to a plane which contains the Sun-perihelion line. The relation of the sail attitude angles between the two symmetrical parts of the orbits are used to reduce the simulation effort. The quasi-heliostationary property at its aphelia is demonstrated with variation of the orbital radius. Evolutions of the orbital velocity and optimal sail orientations are also outlined and discussed to benefit future design work. As is suited for space observation guaranteed by its butterfly shape, the inverse orbits are thoroughly studied in terms of the concerned parameters. The discussion of the parametric influence is ranked in order as perihelion distance r E , required maximum position z max, perihelion position z f and the sail lightness number β. Suitable ranges of each parameter are adopted to illustrate the orbital variation trend. Through numerical simulations the features of such inverse orbits are further emphasized to provide an initial reference for future researchers.

  14. An unconditionally stable method for numerically solving solar sail spacecraft equations of motion

    NASA Astrophysics Data System (ADS)

    Karwas, Alex

    Solar sails use the endless supply of the Sun's radiation to propel spacecraft through space. The sails use the momentum transfer from the impinging solar radiation to provide thrust to the spacecraft while expending zero fuel. Recently, the first solar sail spacecraft, or sailcraft, named IKAROS completed a successful mission to Venus and proved the concept of solar sail propulsion. Sailcraft experimental data is difficult to gather due to the large expenses of space travel, therefore, a reliable and accurate computational method is needed to make the process more efficient. Presented in this document is a new approach to simulating solar sail spacecraft trajectories. The new method provides unconditionally stable numerical solutions for trajectory propagation and includes an improved physical description over other methods. The unconditional stability of the new method means that a unique numerical solution is always determined. The improved physical description of the trajectory provides a numerical solution and time derivatives that are continuous throughout the entire trajectory. The error of the continuous numerical solution is also known for the entire trajectory. Optimal control for maximizing thrust is also provided within the framework of the new method. Verification of the new approach is presented through a mathematical description and through numerical simulations. The mathematical description provides details of the sailcraft equations of motion, the numerical method used to solve the equations, and the formulation for implementing the equations of motion into the numerical solver. Previous work in the field is summarized to show that the new approach can act as a replacement to previous trajectory propagation methods. A code was developed to perform the simulations and it is also described in this document. Results of the simulations are compared to the flight data from the IKAROS mission. Comparison of the two sets of data show that the new approach

  15. Electric solar-wind sail for asteroid touring missions and planetary protection

    NASA Astrophysics Data System (ADS)

    Janhunen, P.

    2014-07-01

    The electric solar-wind sail (electric sail, E-sail [1,2]) is a relatively new concept for moving around in the solar system without consuming propellant and by using the thrust provided by the natural solar wind to produce propulsion. The E-sail is based on deploying, using the centrifugal force, a set of long, thin metallic tethers and charging them to high positive voltage by actively removing negative charge from the system by an electron gun. To make the tethers resistant towards inevitable wire cuts by micrometeoroids, they must be made by bonding from multiple (typically 4) thin (25--50 μ m) aluminium wires. Production of the tethers was a technical challenge which was recently overcome. According to present numerical estimates, the E-sail could produce up to 1 N of propellantless thrust out of less than 200 kg package which is enough to give characteristic acceleration of 1 mm/s^2 to a spacecraft weighing 1 tonne, thus producing 30 km/s of delta-v per year. The thrust scales as ˜ 1/r where r is the solar distance. There are ways to control and vector the thrust enough to enable inward and outward spiralling missions in the solar system. The E-sail working principle has been indirectly measured in a laboratory, and ESTCube-1 CubeSat experiment is underway in orbit (in late March 2014 it was waiting to be started) to measure the E-sail thrust acting on a short 10-m long tether. A full-scale mission requires ˜ 1000 km of tether altogether (weighing ˜10 kg). The production of a 1-km piece of tether has been demonstrated in laboratory [3]. If the E-sail holds up its present promise, it would be ideally suited for asteroid missions because it enables production of similar level of thrust than ion engines, but needs only a small fraction of the electric power and never runs out of propellant because it does not use any (the ''propellant'' being the natural solar-wind plasma flow). Here we consider especially a mission which would tour the asteroid belt for a

  16. Gamma-Ray Burst Polarimeter (GAP) aboard the Small Solar Power Sail Demonstrator IKAROS

    NASA Astrophysics Data System (ADS)

    Yonetoku, Daisuke; Murakami, Toshio; Gunji, Shuichi; Mihara, Tatehiro; Sakashita, Tomonori; Morihara, Yoshiyuki; Kikuchi, Yukihiro; Takahashi, Takuya; Fujimoto, Hirofumi; Toukairin, Noriyuki; Kodama, Yoshiki; Kubo, Shin; Ikaros Demonstration Team

    2011-06-01

    The small solar-power sail demonstrator ``IKAROS'' is a Japanese engineering verification spacecraft launched by the H-IIA rocket on 2010 May 21 at Japan Aerospace Exploration Agency (JAXA) Tanegashima Space Center. IKAROS has a 20 m diameter sail, which is made of a thin polyimide membrane. The sail converts the solar radiation-pressure into the propulsion force of IKAROS, and accelerates the spacecraft. The Gamma-Ray Burst Polarimeter (GAP) aboard IKAROS is the first polarimeter specifically designed to measure the polarization of Gamma-Ray Bursts (GRBs) from space, and will do so in the cruising phase of the IKAROS mission. GAP is a modest detector of 3.8 kg in weight and 17 cm in size with an energy range of between 50-300 keV. The GAP detector is now a member of the interplanetary network (IPN) for determining the GRB direction. The detection principle of gamma-ray polarization is the anisotropy of the Compton scattering. Coincidence between the central plastic Compton scattering medium and discrete CsI detectors distributed around the sides of the plastic defines the Compton-scattering angle, which is expected to show an angular dependence if polarization is present in a given GRB. In this paper, we present the GAP detector and its ground-based and onboard calibrations.

  17. COSMOS 1: the Attempt to Fly the First Solar Sail Mission

    NASA Astrophysics Data System (ADS)

    Friedman, L.; Pichkhadze, K.; Kudryashov, V.; Rogovsky, G.; Linkin, V.; Gotlib, V.; Lipatov, A.; Cantrell, J.; Garvey, J.

    Cosmos 1 is a privately funded mission, the first ever attempted by a space interest organization. Sponsored by Cosmos Studios and the Arts and Entertainment Network, it is being carried out by The Planetary Society. The spacecraft is being developed and will be launched in Russia by a team headed by the Babakin Space Center and the Space Research Institute. The goal is to provide the first demonstration of solar sailing. It is hoped that such a technology demonstration mission that will open the way for solar sailing to reach its documented potential for low cost and round trip interplanetary missions, (Friedman et. al., 1978) and eventually for interstellar flight. Cosmos 1's mission success is defined as the spacecraft's orbital period (energy or semi-major axis) being measurably increased by controlled flight using sunlight pressure to increase orbital velocity. To achieve this goal, the spacecraft must fly above the sensible atmosphere so that atmospheric drag is inconsequential compared to the solar radiation pressure. Normally, a solar sail is designed to fly in deep space away from planetary gravity wells such as Earth's. The complexity of our task of demonstrating the flight of the solar sail is dramatically increased by the need to re-orient the sails several times per orbit and the presence of Earth's atmosphere. Further complicating matters is our launch date in 2002, which is near a time of solar maximum when the atmosphere extends to higher altitudes than normal. To avoid being trapped by the Earth's atmosphere, we have to go to at least 800 kilometers altitude to begin our orbital flight. This can be achieved with our planned launch on a Volna rocket from the Barents Sea in Russia. Volna is a converted submarine launched ballistic missile, the SS-N-18, developed and operated by the Makeev Rocket Design Bureau, within RosAviaKosmos, the Russian space agency. In addition to the 3-stage Volna, an orbit insertion motor is required. Babakin Space Center

  18. High performance two degrees of freedom attitude control for solar sails

    NASA Astrophysics Data System (ADS)

    Romagnoli, Daniele; Oehlschlägel, Thimo

    2011-12-01

    The purpose of this paper is to present a high performance solar sail attitude controller which uses ballast masses moving inside the sail's booms as actuators and to demonstrate its ability of performing time efficient reorientation maneuvers. The proposed controller consists of a combination of a feedforward and a feedback controller, which takes advantage of the feedforward's fast response and the feedback's ability of responding to unpredicted disturbances. The feedforward controller considers the attitude dynamics of the sailcraft as well as the disturbance torque due to the center of pressure offset to the center of mass of the sailcraft. Additional disturbance torques, like those coming from the environment or from asymmetry of the spacecraft structure, are then handled by the feedback controller. Simulation performance results are finally compared against results available in the literature.

  19. Large Angle Reorientation of a Solar Sail Using Gimballed Mass Control

    NASA Astrophysics Data System (ADS)

    Sperber, E.; Fu, B.; Eke, F. O.

    2016-03-01

    This paper proposes a control strategy for the large angle reorientation of a solar sail equipped with a gimballed mass. The algorithm consists of a first stage that manipulates the gimbal angle in order to minimize the attitude error about a single principal axis. Once certain termination conditions are reached, a regulator is employed that selects a single gimbal angle for minimizing both the residual attitude error concomitantly with the body rate. Because the force due to the specular reflection of radiation is always directed along a reflector's surface normal, this form of thrust vector control cannot generate torques about an axis normal to the plane of the sail. Thus, in order to achieve three-axis control authority a 1-2-1 or 2-1-2 sequence of rotations about principal axes is performed. The control algorithm is implemented directly in-line with the nonlinear equations of motion and key performance characteristics are identified.

  20. Large Angle Reorientation of a Solar Sail Using Gimballed Mass Control

    NASA Astrophysics Data System (ADS)

    Sperber, E.; Fu, B.; Eke, F. O.

    2016-06-01

    This paper proposes a control strategy for the large angle reorientation of a solar sail equipped with a gimballed mass. The algorithm consists of a first stage that manipulates the gimbal angle in order to minimize the attitude error about a single principal axis. Once certain termination conditions are reached, a regulator is employed that selects a single gimbal angle for minimizing both the residual attitude error concomitantly with the body rate. Because the force due to the specular reflection of radiation is always directed along a reflector's surface normal, this form of thrust vector control cannot generate torques about an axis normal to the plane of the sail. Thus, in order to achieve three-axis control authority a 1-2-1 or 2-1-2 sequence of rotations about principal axes is performed. The control algorithm is implemented directly in-line with the nonlinear equations of motion and key performance characteristics are identified.

  1. Solar sailing for radio astronomy and seti: An extrasolar mission to 550 AU

    NASA Astrophysics Data System (ADS)

    Matloff, Gregory L.

    1994-11-01

    Current or near-term technology is capable of propelling small payloads to 550 Astronomical Units (AU) on flights of decades duration. Beyond 550 AU, natural or artificial electromagnetic (EM) radiation emitted by galactic objects occulted by the Sun is greatly amplified by solar gravitational focusing. Propulsion systems capable of launching such an extrasolar probe include Jupiter gravity-assist, flat or inflatable solar sails unfurled from parabolic solar orbits sunward of the Earth, and the proton-reflecting 'Magsail'. Best performance for a near-future probe is obtained using the solar sail; a superconducting Magsail has great potential for course-correction purposes. A properly configured solar sail can also serve as a radio telescope and as a solar-energy collector to power the probe's instrumentation. The best direction for the probe's trajectory is towards the galactic anti-center. This is because of the astrophysical interest in amplified EM radiation from the galactic center and the large number of Sunlike stars in the galactic arm. Many of these stars could be surveyed for artificial radio emissions using the proposed probe by astronomers engaged in SETI (Search for ExtraTerrestrial Intelligence). By chance, the anti-galactic-center is not too far from the positions on the celestial sphere of the nearby Sunlike stars Tau Ceti and Epsilon Eridani. This random celestial arrangement increases the potential interest of the proposed mission. While focused on or near the galactic center, the probe could also examine a number of objects of astrophysical interest. These include supernova remnants, HI and HIII regions, and neutron stars or black holes near the galctic center. A number of alternative directions for probes of this type exists. Missions could be flown to sample amplified radio emissions from globular clusters such as M13 and M22 and extra-galactic objects such as the Magellanic Clouds and the Great Spiral Galaxy (M31) in Andromeda. For a number of

  2. Dynamics of highly-flexible solar sail subjected to various forces

    NASA Astrophysics Data System (ADS)

    Liu, Jiafu; Cui, Naigang; Shen, Fan; Rong, Siyuan

    2014-10-01

    Solar sail is a novel spacecraft and has the potential applications in the near future. The large amplitude vibration should be considered because it is characterized by its huge and lightweight structure. In this paper, the supporting beam of solar sail is regarded as the most important structure and used to model the sailcraft as it accounts for most of the mechanical energies when it is in deformed configuration, also as the Euler beam can model the bending motion dominant sailcraft when it experiences attitude motions. The structural dynamics of solar sail supporting beam with geometric nonlinearity undergoing the forces generated by solar radiation pressure, sliding masses and control vanes are presented. The axial and transverse vibration equations with the properties of strong coupling, nonlinearity and time-varying coefficient matrices are obtained by using Lagrange equation method after calculating the related energies and works. The vibration equations are transformed into nonlinear algebraic equations utilizing implicit unconditionally stable Newmark-β algorithm for each time step. The nonlinear algebraic equations are solved by Newton-iterative algorithm. We compute and analyze the linear and nonlinear vibration responses affected by the mass and velocity of the sliding mass, the angular velocity of the force generated by control vane in detail. The computational results indicate that the mass and velocity of sliding mass affect the vibration responses (including the vibration frequency), but the angular velocity of the force generated by control vane hardly affects the vibration responses. Moreover, the linear and nonlinear vibrations are distinct obviously by comparing the linear and nonlinear responses. It is demonstrated that the geometric nonlinearity of the highly-flexible structure should be considered for performing vibration analysis exactly, and the vibration responses excited by the prescribed motion of the attitude control actuators should

  3. Development and Ground Testing of a Compactly Stowed Scalable Inflatably Deployed Solar Sail

    NASA Technical Reports Server (NTRS)

    Lichodziejewski, David; Derbes, Billy; Reinert, Rich; Belvin, Keith; Slade, Kara; Mann, Troy

    2004-01-01

    This paper discusses the solar sail design and outlines the interim accomplishments to advance the technology readiness level (TRL) of the subsystem from 3 toward a technology readiness level of 6 in 2005. Under Phase II of the program many component test articles have been fabricated and tested successfully. Most notably an unprecedented section of the conically deployed rigidizable sail support beam, the heart of the inflatable rigidizable structure, has been deployed and tested in the NASA Goddard thermal vacuum chamber with good results. The development testing validated the beam packaging and deployment. The inflatable conically deployed, Sub Tg rigidizable beam technology is now in the TRL 5-6 range. The fabricated masses and structural test results of our beam components have met predictions and no changes to the mass estimates or design assumptions have been identified adding great credibility to the design. Several quadrants of the Mylar sail have also been fabricated and successfully deployed validating our design, manufacturing, and deployment techniques.

  4. New applications of the H-reversal trajectory using solar sails

    NASA Astrophysics Data System (ADS)

    Zeng, Xiang-Yuan; Baoyin, Hexi; Li, Jun-Feng; Gong, Sheng-Ping

    2011-07-01

    Advanced solar sailing has been an increasingly attractive propulsion system for highly non-Keplerian orbits. Three new applications of the orbital angular momentum reversal (H-reversal) trajectories using solar sails are presented: space observation, heliocentric orbit transfer and collision orbits with asteroids. A theoretical proof for the existence of double H-reversal trajectories (referred to as ‘H2RTs’) is given, and the characteristics of the H2RTs are introduced before a discussion of the mission applications. A new family of H2RTs was obtained using a 3D dynamic model of the two-body frame. In a time-optimal control model, the minimum period H2RTs both inside and outside the ecliptic plane were examined using an ideal solar sail. Due to the quasi-heliostationary property at its two symmetrical aphelia, the H2RTs were deemed suitable for space observation. For the second application, the heliocentric transfer orbit was able to function as the time-optimal H-reversal trajectory, since its perihelion velocity is a circular or elliptic velocity. Such a transfer orbit can place the sailcraft into a clockwise orbit in the ecliptic plane, with a high inclination or displacement above or below the Sun. The third application of the H-reversal trajectory was simulated impacting an asteroid passing near Earth in a head-on collision. The collision point can be designed through selecting different perihelia or different launch windows. Sample orbits of each application were presented through numerical simulation. The results can serve as a reference for theoretical research and engineering design.

  5. A Jovian Small Orbiter for Magnetospheric and Auroral Studies with the Solar-Sail Project

    NASA Astrophysics Data System (ADS)

    Kasaba, Y.; Takashima, T.; Misawa, H.

    2009-06-01

    The Solar-Sail Project has been investigated by JAXA as an engineering mission with a small orbiter into the Jovian orbit. This paper summarizes the basic design of this project and possible Jovian system studies by this opportunity. The large-scale Jovian mission has been discussed as a long future plan since the 1970s, when the investigation of the future planetary exploration program started in Japan. The largest planet and its complex planetary system would be studied by several main objectives: (1) The structure of a gas planet: the internal and atmospheric structures of a gas planet which could not be a star. (2) The Jovian-type magnetosphere: the structure and processes of the largest and strongest magnetosphere in the solar system. (3) The structure, composition, and evolution of Jupiter and its satellite system. The small Jovian orbiter accompanied with the Solar-Sail Project will try to establish the technical feasibility of such future outer planet missions in Japan. The main objective is the second target, the Jovian magnetospheric and auroral studies with its limited payload resources.

  6. Mercury Sample Return and Small-Body Encounters Using Solar Sail Propulsion

    NASA Astrophysics Data System (ADS)

    Hughes, Gareth W.; McInnes, Colin R.

    Missions to planet Mercury have large V requirements, which impose almost unattainable demands on a Chemical propellant budget. Ion Propulsion is a viable alternative, but single or multiple gravity assists are necessary to conserve propellant. The propellant budget required to return a sample makes Chemical and Ion propulsion seem very unattractive. Solar sails exhibit an extremely high effective specific impulse over long mission durations at minimal mission expenditure. Propellant mass is not an issue, so large changes in V can be realised without necessitating the implementation of complex gravity assists, which prolong mission duration and restrict launch opportunities. Solar sails are ideal candidates for enabling orbital operations within the inner Solar System, and particularly for sample return missions, because of the inverse square proportionality of the heliocentric distance to the thrust magnitude. In this research work we have used a parameterised approach to sail control representation. The sail cone and clock angle histories were characterised by linear interpolation across a set of discrete nodes. The optimal control problem was thus transcribed to a Non-Linear Programming problem to select the optimal controls at the nodes that minimised the transfer time while enforcing the cartesian end-point boundary constraints (6 states for rendezvous). The Fortran77 optimisation package NPSOL 5.0 was used for this purpose with the variational equations of motion formulated in modified equinoctial orbital elements and integrated using a variable-order, adaptive step-size Adams-Moulton-Bashforth method. It has been ascertained that a sample could be returned from Mercury with a total interplanetary transit time of 4.5 years. The total sample return mission duration was 5.73 years if solar sail propulsion was utilised for the planetary capture and escape phases and to allow for lander descent, sample acquisition and ascent from the surface. This total mission

  7. Sail '76

    ERIC Educational Resources Information Center

    Vandewalle, Raymond

    1976-01-01

    A new nationwide program called Sail '76 has been launched to give more people the opportunity to try the sport of sailing and to teach people the proper sailing techniques before they invest in a sailboat. (SK)

  8. Solar sail applications for mission design in sun-planet systems from the perspective of the circular restricted three-body problem

    NASA Astrophysics Data System (ADS)

    Sood, Rohan

    2012-06-01

    As a consequence of the successful harnessing of solar radiation pressure demonstrated by JAXA's IKAROS mission, the interest and developments in the field of solar sails has gained a significant momentum. Sail-based spacecraft potentially offer indefinite maneuvering capability by exploiting photons from the Sun as a means of propulsion. Incorporating a solar sail model within the context of the circular restricted three-body problem extends trajectory design options. In the last few decades, the Lagrangian points, L i, as defined in the restricted problem, have increasingly become a focus for scientific spacecraft mission applications. In this investigation, a hybrid model that incorporates a solar sail force into the circular restricted three-body problem (SS-CR3BP) is developed. As a result of the additional force, the displaced locations of artificial collinear Lagrangian points are determined and exploited for trajectory design. In fact, various trajectories are constructed that employ only sail orientation angles to move through this dynamical regime. In particular, periodic orbits are computed in the vicinity of the displaced artificial L1 equilibrium point, located between the Sun and the Earth in this Sun-planet system. A sample offset periodic orbit is demonstrated that hovers over the displaced L1 point. Trajectory modifications are performed in the vicinity of the L1 equilibrium point using solar sail angles. Three-dimensional transfers between halos at three different sizes is also constructed to exhibit the capabilities of solar sails based on specific mission objectives. Thus, in this investigation, solar sail capabilities that widen the design space for mission design in the restricted three-body problem are explored.

  9. Surface Experiments on a Jupiter Trojan Asteroid in the Solar Powered Sail Mission

    NASA Astrophysics Data System (ADS)

    Okada, Tatsuaki

    2016-04-01

    Introduction: A new mission to a Jupiter Trojan asteroid is under study us-ing a solar-powered sail (SPS), and a science lander is being investigated in the joint study between Japan and Europe [1]. We present here the key sci-entific objectives and the strawman payloads of science experiments on the asteroid. Science Objectives: Jupiter Trojan asteroids are located around the Sun-Jupiter Lagrange points (L4 or L5) and most of them are classified as D- or P-type in asteroid taxonomy, but their origin still remains unknown. A classi-cal (static) model of solar system evolution indicates that they were formed around the Jupiter region and survived until now as the outer end members of asteroids. A new (dynamical) model such as Nice model suggests that they were formed at the far end of the solar system and transferred inward due to dynamical migration of giant planets [2]. Therefore physical, miner-alogical, and isotopic studies of surface materials and volatile compounds could solve their origin, and then the solar system formation [3]. Strawman Payloads: The SPS orbiter will be able to carry a 100 kg class lander with 20 kg mission payloads. Just after landing of the lander, geolog-ical, mineralogical, and geophysical observations will be performed to char-acterize the site using a panoramic optical camera, an infrared hyperspectral imager, a magnetometer, and a thermal radiometer. The surface and subsur-face materials of the asteroid will be collected into a carousel by the bullet-type and the pneumatic drill type samplers, respectively. Samples in the carousel will be investigated by a visible and an infrared microscope, and transferred for performing high resolution mass spectrometry (HRMS). Mass resolution m/dm > 30,000 is expected to investigate isotopic ratios of D/H, 15N/14N, and 18O/16O, as well as molecules from organic matters. A set of strawman payloads are tentatively determined during the lander system study [4]. The constraints to select the strawman

  10. FeatherSail--Design, Development and Future Impact

    NASA Technical Reports Server (NTRS)

    Alhorn, Dean C.; Scheierl, John M.

    2010-01-01

    This CD contains the slide presentation and a brief video of the solar sail concept. Solar Sailing is a method of space flight propulsion, which utilizes the light photons to propel spacecrafts through the vacuum of space. The goal of the FeatherSail project is to create a sail vehicle with the ability to provide steering from the sails and increase the areal density.

  11. FeatherSail - The Next Generation Nano-Class Sail Vehicle

    NASA Technical Reports Server (NTRS)

    Alhom, Dave C.

    2010-01-01

    Solar sail propulsion is a concept, which will soon become a reality. Solar sailing is a method of space flight propulsion, which utilizes the light photons to propel spacecrafts through the vacuum of space. Solar sail vehicles have generally been designed to have a very large area. This requires significant time and expenditures to develop, test and launch such a vehicle. Several notable solar propulsion missions and experiments have been performed and more are still in the development stage. This concept will be tested in the near future with the launch of the NanoSail-D satellite. NanoSail-D is a nano-class satellite, less than 10kg, which will deploy a thin lightweight sheet of reflective material used to propel the satellite in its low earth orbit. The NanoSail-D solar sail design is used for the basic design concept for the next generation of nanoclass solar sail vehicles. The FeatherSail project was started to develop a solar sail vehicle with the capability to perform attitude control via rotating or feathering the solar sails. In addition to using the robust deployment method of the NanoSail-D system, the FeatherSail design incorporates other novel technologies. These technologies include deployable thin film solar arrays and low power, low temperature Silicon-Germanium electronics. Together, these three technological advancements provide a starting point for smaller class sail vehicles. These smaller solar sail vehicles provide a capability for inexpensive missions to explore beyond the realms of low earth orbit.

  12. Solar sail trajectory design in the Earth-Moon circular restricted three body problem

    NASA Astrophysics Data System (ADS)

    Das, Ashwati

    The quest to explore the Moon has helped resolve scientific questions, has spurred leaps in technology development, and has revealed Earth's celestial companion to be a gateway to other destinations. With a renewed focus on returning to the Moon in this decade, alternatives to chemical propulsion systems are becoming attractive methods to efficiently use scarce resources and support extended mission durations. Thus, an investigation is conducted to develop a general framework, that facilitates propellant-free Earth-Moon transfers by exploiting sail dynamics in combination with advantageous transfer options offered in the Earth-Moon circular restricted multi-body dynamical model. Both periodic orbits in the vicinity of the Earth-Moon libration points, and lunar-centric long-term capture orbits are incorporated as target destinations to demonstrate the applicability of the general framework to varied design scanarios, each incorporating a variety of complexities and challenges. The transfers are comprised of three phases - a spiral Earth escape, a transit period, and, finally, the capture into a desirable orbit in the vicinity of the Moon. The Earth-escape phase consists of spiral trajectories constructed using three different sail steering strategies - locally optimal, on/off and velocity tangent. In the case of the Earth-libration point transfers, naturally occurring flow structures (e.g., invariant manifolds) arising from the mutual gravitational interaction of the Earth and Moon are exploited to link an Earth departure spiral with a destination orbit. In contrast, sail steering alone is employed to establish a link between the Earth-escape phase and capture orbits about the Moon due to a lack of applicable natural structures for the required connection. Metrics associated with the transfers including flight-time and the influence of operational constraints, such as occultation events, are investigated to determine the available capabilities for Earth

  13. Near-Term Interstellar Sailing

    NASA Technical Reports Server (NTRS)

    Matloff, Gregory L.; Taylor, Travis; Powell, Conley; Moton, Tryshanda; Robinson, Don

    2004-01-01

    A number of techniques are investigated that allow the possibility of near- ecliptic exploration beyond the Sun's heliopause (200 AU) using contemporary solar-sail spacecraft (with areal mass thickness about 0.0082 kilograms per square meters). Maximum mission duration to the heliopause was defined as one human working lifetime; missions to the Sun's gravity focus at 550 AU from the sun must take less time than one human lifetime. Options include unfurling the sail at the 0.2-AU perihelion of a parabolic solar orbit, unfurling the sail at the 0.2-AU perihelion of a 2.5-AU aphelion solar orbit, and performing a grazing gravity-assist flyby of Jupiter. Although these techniques are capable of performing the defined mission, higher-technology sails are faster.

  14. On the Trojan asteroid sample and return mission via solar-power sail -- an innovative engineering demonstration

    NASA Astrophysics Data System (ADS)

    Kawaguchi, J.; Mori, O.; Shirasawa, Y.; Yoshikawa, M.

    2014-07-01

    The science and engineering communities in the world are seeking what comes next. Especially for asteroids and comets, as those objects lie in relatively far area in our solar system, and new engineering solutions are essential to explore them. JAXA has studied the next-step mission since 2000, a solar-power sail demonstrator combining the use of photon propulsion with electric propulsion, ion thruster, targeting the untrodden challenge for the sample return attempt from a Trojan asteroid around the libration points in the Sun-Jupiter system. The Ikaros spacecraft was literally developed and launched as a preliminary technology demonstration. The mission will perform in-situ measurement and on-site analysis of the samples in addition to the sample return to the Earth, and will also deploy a small lander on the surface for collecting surface samples and convey them to the mother spacecraft. From a scientific point of view, there is an enormous reward in the most primitive samples containing information about the ancient solar system and also about the origin of life in our solar system. JAXA presently looks for international partners to develop and build the lander. The presentation will elaborate the current mission scenario as well as what we think the international collaboration will be.

  15. Performance Comparisons and Down Selection of Small Motors for Two-Blade Heliogyro Solar Sail 6U CubeSat

    NASA Technical Reports Server (NTRS)

    Wiwattananon, Peerawan; Bryant, Robert G.

    2015-01-01

    This report compiles a review of 130 commercial small scale motors (piezoelectric and electric motors) and almost 20 researched-type small scale piezoelectricmotors for potential use in a 2 blades Heliogyro Solar Sail 6U CubeSat. In this application, a motor and gearhead (drive system) will deploy a roll of solar sailthin film (2 um thick)accommodated in a 2U CubeSat (100 x 200 x 100 mm) housing. The application requirements are: space rated, output torque at fulldeployment of 0.8 Nm, reel speed of 3 rpm, drive system weight limited to 150 grams, diameter limited to 50 mm, and the length not to exceed 40 mm. The 50mm diameter limit was imposed as motors with larger diameters would likely weigh too much and use more space on the satellite wall. This would limit theamount of the payload. The motors performance are compared between small scale, volume within 3x102 cm3 (3x105 mm3), commercial electric DC motors,commercial piezoelectric motors, and researched-type (non-commercial) piezoelectric motors extracted from scientific and product literature. The comparisonssuggest that piezoelectric motors without a gearhead exhibit larger output torque with respect to their volume and weight and require less input power toproduce high torque. A commercially available electric motor plus a gearhead was chosen through a proposed selection process to meet the applications designrequirements.

  16. FeatherSail - Design, Development and Future Impact

    NASA Technical Reports Server (NTRS)

    Alhorn, Dean C.; Scheierl, J. M.

    2010-01-01

    To the present day, the idea of using solar sails for space propulsion is still just a concept, but one that provides a great potential for future space exploration missions. Several notable solar propulsion missions and experiments have been performed and more are still in the development stage. Solar Sailing is a method of space flight propulsion, which utilizes the light photons to propel spacecrafts through the vacuum of space. This concept will be tested in the near future with the launch of the NanoSail-D satellite. NanoSail-D is a nano-class satellite, <10kg, which will deploy a thin lightweight sheet of reflective material used to propel the satellite in its low earth orbit. Using the features of the NanoSail-D architecture, a second-generation solar sail design concept, dubbed FeatherSail, has been developed. The goal of the FeatherSail project is to create a sail vehicle with the ability to provide steering from the sails and increase the areal density. The FeatherSail design will utilize the NanoSail-D based extendable boom technology with only one sail on each set of booms. This design also allows each of the four sails to feather as much as ninety degrees. The FeatherSail concept uses deployable solar arrays to generate the power necessary for deep space missions. In addition, recent developments in low power, low temperature Silicon-Germanium electronics provide the capability for long duration deep space missions. It is envisioned that the FeatherSail conceptual design will provide the impetus for future sail vehicles, which may someday visit distant places that mankind has only observed.

  17. Revealing Exo-Zody and Exo-Planets from Solar System Dust Measurements: ALADDIN-2 for the Solar Power Sail Mission

    NASA Astrophysics Data System (ADS)

    Yano, Hajime; Hirai, Takayuki

    2016-07-01

    The dust structure of our Solar System provides a benchmark information of dust disks of other exo-planetary systems in general, just like the Sun as the closest main sequence G-star that we can study with the most details. Heliocentric dust distributions and gravitational and orbital interactions with planets such as mean motion resonances (MMRs) of dust flux of our Solar System are what we can transfer the knowledge of our Solar System dust apply to infer anisotropic exo-zodiacal brightness, or spatial structures within a exo-planetary dust disks with information about potentially embedded planets inside. In the coming era of disk resolved observations by ALMA, TMT and other new telescopes, we will be able to apply what we find in the Solar System to the rest of planetary systems. In 2010-11, the IKAROS solar sail spacecraft carried the ALADDIN large area dust detector array to study large meteoroids between the Earth and Venus orbits. Yano et al. directly detected both the Earth's and Venus' MMRs dust structures, being consistent with numerical simulations that predict the existence of such local enhancements of dust distribution around these terrestrial planets, as well as Neptune. JAXA's Solar Power Sail mission plans to carry even larger dust detector inherited the technology onboard IKAROS, namely ALADDIN-2 in order to search for such MMRs in the Mars and Jupiter orbits, as predicted by Kuchner et al.(2000), in addition to make a continuous measurement of large dust flux from 1.0 to 5.2 AU crossing the main asteroid belt up to Jupiter Trojan region. It is also noted that recent reanalysis of the Pioneer 10 and 11 photo polarimeter data suggests a small enhancement of the brightness towards the anti-solar direction near Jupiter the largest planet of our Solar System, implying a possible existence of a dust belt related to the planet. The spatial density of dust particles directly measured by the ALADDIN-2 will provide a more conclusive and direct proof due to

  18. TENEX SAIL

    NASA Technical Reports Server (NTRS)

    Smith, R.

    1975-01-01

    SAIL, a high level ALGOL language for the PDP-10, is extended to operate under the TENEX time sharing system without executing DEC system calls. A large set of TENEX oriented runtime routines are added to allow complete access to TENEX. The emphasis is on compatibility of programs across time sharing systems and integrity of the language.

  19. Flying on Sun Shine: Sailing in Space

    SciTech Connect

    Alhorn, Dean

    2012-03-28

    On January 20th, 2011, NanoSail-D successfully deployed its sail in space. It was the first solar sail vehicle to orbit the earth and the second sail ever unfurled in space. The 10m2 sail, deployment mechanism and electronics were packed into a 3U CubeSat with a volume of about 3500cc. The NanoSail-D mission had two objectives: eject a nanosatellite from a minisatellite; deploy its sail from a highly compacted volume to validate large structure deployment and potential de-orbit technologies. NanoSail-D was jointly developed by NASA's Marshall Space Flight Center and Ames Research Center. The ManTech/NeXolve Corporation provided key sail design support. NanoSail-D is managed by Marshall and jointly sponsored by the Army Space and Missile Defense Command, the Space Test Program, the Von Braun Center for Science and Innovation and Dynetics Inc. The presentation will provide insights into sailcraft advances and potential missions enabled by this emerging in-space propulsion technology.

  20. The life cycle of Ice Sails

    NASA Astrophysics Data System (ADS)

    Evatt, Geoff; Mayer, Christoph; Abrahams, I. d.; Nicholson, Lindsey; Mallinson, Amy; Heil, Matthias

    2016-04-01

    The Karakoram mountain region is host to many debris-covered glaciers. A notable feature from a sub-set of mainly larger glaciers with flat tongues, is the phenomenon of `Ice Sails'. These Ice Sails are clean ice structures that protrude out of the surrounding debris-covered glacier. They can be up to 20 meters in height, with widths of up to 90 meters, and generally have flat-sided faces. They appear to grow out of areas of glacier with thin debris coverage, then persist for decades as the glacier flows downstream, before declining back into the glacier several kilometres later. Here we aim to define and categorise these ice structures, and then explain their growth, persistence and decay. In particular, we show that their growth is due to the melt rate of inclined clean-ice being smaller than that of the surrounding flat thinly-debris-covered ice, allowing these structures to appear to grow out of the debris layer. But as the glacier flows downstream, this debris thickness slowly thickens, causing the corresponding melt-rate of the underlying ice to decline. Eventually, the melt-rate of the debris-covered ice becomes lower than that of the Ice Sail's melt-rate, at which point the decaying process of the Ice Sail commences. We develop a model to quantify this process, and in so doing, draw out the key parameters that govern the existence of Ice Sails.

  1. Photon Sail History, Engineering, and Mission Analysis. Appendix

    NASA Technical Reports Server (NTRS)

    Matloff, Gregory L.; Taylor, Travis; Powell, Conley

    2004-01-01

    This Appendix summarizes the results of a Teledyne Brown Engineering, Inc. report to the In-Space propulsion research group of the NASA Marshall Space Flight Center (MSFC) that was authored by Taylor et al. in 2003. The subject of this report is the technological maturity, readiness, and capability of the photon solar sail to support space-exploration missions. Technological maturity for solar photon sail concepts is extremely high high for rectangular (or square) solar sail configurations due to the historical development of the rectangular design by the NASA Jet Propulsion Laboratory (JPL). L'Garde Inc., ILC Dover Inc., DLR, and many other corporations and agencies. However, future missions and mission analysis may prove that the rectangular sail design is not the best architecture for achieving mission goals. Due to the historical focus on rectangular solar sail spacecraft designs, the maturity of other architectures such as hoop-supported disks, multiple small disk arrays, parachute sails, heliogyro sails, perforated sails, multiple vane sails (such as the Planetary Society's Cosmos 1), inflated pillow sails, etc., have not reached a high level of technological readiness. (Some sail architectures are shown in Fig. A.1.) The possibilities of different sail architectures and some possible mission concepts are discussed in this Appendix.

  2. Solar sail attitude control including active nutation damping in a fixed-momentum wheel satellite

    NASA Technical Reports Server (NTRS)

    Azor, Ruth

    1992-01-01

    In geostationary cruise of a momentum biased satellite, it is necessary to stabilize the roll/yaw attitude due to disturbances, caused mainly by solar radiation pressure. This work presents a roll/yaw control which is obtained by the use of solar arrays and fixed flaps as actuators, with a horizon sensor for roll measurement. The design also includes an active nutation damping.

  3. Sailing the Sun field and the mathematics of the Solar System

    NASA Astrophysics Data System (ADS)

    Gómez de Castro, A. I.; López-Martinez, F.; Lozano, C.; Rodrigo-Gudiel, V.

    2012-09-01

    The Solar System is an explendid laboratory for students to think and apply the mathematics learnt at high school level. To assist teachers to introduce some concepts making use of Solar System exploration we have developed a set of tools that are interfaced through a wiki service. This contribution is aimed at presenting this service and some of the tools made available to the community.

  4. SUNSPOT: A computer program for producing optimal solar sail planetocentric trajectories

    NASA Technical Reports Server (NTRS)

    Sackett, L. L.

    1977-01-01

    The input, output and subroutines, including listings, for the SUNSPOT code are described. SUNSPOT can calculate time optimal planetocentric trajectories including orbit-to-orbit transfer and orbit to a subescape point. Trajectories about the the four inner planets can be calculated, and shadowing, oblateness, and solar motion may be included. A penalty function may be included to prevent trajectories which intersect the planet's surface.

  5. European Sail Tower SPS concept

    NASA Astrophysics Data System (ADS)

    Seboldt, W.; Klimke, M.; Leipold, M.; Hanowski, N.

    2001-03-01

    Based on a DLR-study in 1998/99 on behalf of ESA/ESTEC called "System Concepts, Architectures and Technologies for Space Exploration and Utilization (SE&U)" a new design for an Earth-orbiting Solar Power Satellite (SPS) has been developed. The design is called "European Sail Tower SPS" and consists mainly of deployable sail-like structures derived from the ongoing DLR/ESA solar sail technology development activity. Such a SPS satellite features an extremely light-weight and large tower-like orbital system and could supply Europe with significant amounts of electrical power generated by photovoltaic cells and subsequently transmitted to Earth via microwaves. In order to build up the sail tower, 60 units - each consisting of a pair of square-shaped sails - are moved from LEO to GEO with electric propulsion and successively assembled in GEO robotically on a central strut. Each single sail has dimensions of 150m × 150 m and is automatically deployed, using four diagonal light-weight carbon fiber (CFRP) booms which are initially rolled up on a central hub. The electric thrusters for the transport to GEO could also be used for orbit and attitude control of the assembled tower which has a total length of about 15 km and would be mainly gravity gradient stabilized. Employing thin film solar cell technology, each sail is used as a solar array and produces an electric power in orbit of about 3.7 MW e. A microwave antenna with a diameter of 1 km transmits the power to a 10 km rectenna on the ground. The total mass of this 450 MW SPS is about 2100 tons. First estimates indicate that the costs for one kWh delivered in this way could compete with present day energy costs, if launch costs would decrease by two orders of magnitude. Furthermore, mass production and large numbers of installed SPS systems must be assumed in order to lower significantly the production costs and to reduce the influence of the expensive technology development. The paper presents the technical concept

  6. An Interstellar Sail before 2020?

    NASA Astrophysics Data System (ADS)

    Matloff, G. L.; Johnson, L.

    In 2017, NASA plans to launch the Near Earth Asteroid (NEA) Scout, a solar-photon-sail propelled probe to rendezvous with one or more near-Earth asteroids. According to a publication describing early design parameters, the spacecraft mass is 12 kg and the square sail has an area of 83 square meters. This craft, like many other NASA science missions, will likely remain functional after the completion of its primary mission. This paper investigates options for application of this spacecraft during its extended mission as an Interstellar Trailblazer. As well as kinematics, thermal aspects and the communications challenges are discussed. Although interstellar velocities for this craft will not be high and engineering the pre-perihelion trajectory will be challenging, an extended demonstration mission of this type would certainly spur interest in the development of true interstellar sails. As of December 2014, the design of this spacecraft continues to evolve. The performance estimates presented here may be overly conservative.

  7. Recent Advances in Electric Sail Development

    NASA Astrophysics Data System (ADS)

    Janhunen, P.

    2009-04-01

    The electric solar wind sail is a newly invented way for using the solar wind dynamic pressure for providing thrust for a spacecraft. An electric sail spacecraft deploys long, thin, conducting tethers which are centrifugally stretched and kept in a high positive potential by a continuously working onboard electron gun. A positively charged wire embedded in solar wind plasma produces a Debye sheath around itself. Inside the sheath, the wire electric field repels solar wind protons so that they are deflected from their originally straight trajectories and thereby give some of their momentum to the wire. The solar wind dynamic pressure (on average 2 nPa at 1 AU distance) is about 5000 times weaker than the radiation pressure of the Sun, but since the wire's Debye sheath can be more than million times larger than the wire's physical diameter, the electric sail can be a mass-efficient method of spacecraft propulsion. If realised, the Electric Sail will be a significant and direct technical utilisation of a naturally occurring space plasma flow. We give an overview of the present status of the Electric Sail effort, reviewing its plasma physical basis and some technical aspects and potential applications. One application for the Electric Sail could be to implement the Interstellar Heliopause Probe, that is, a flight across the heliopause with less than 20-25 years of traveltime.

  8. Plasma Sail Concept Fundamentals

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Delamere, P.; Kabin, K.; Linde, T. J.

    2004-01-01

    The mini-magnetospheric plasma propulsion (M2P2) device, originally proposed by Winglee et al., predicts that a 15-km standoff distance (or 20-km cross-sectional dimension) of the magnetic bubble will provide for sufficient momentum transfer from the solar wind to accelerate a spacecraft to unprecedented speeds of 50 C80 km/s after an acceleration period of 3 mo. Such velocities will enable travel out of the solar system in period of 7 yr almost an order of magnitude improvement over present chemical-based propulsion systems. However, for the parameters of the simulation of Winglee et al., a fluid model for the interaction of M2P2 with the solar wind is not valid. It is assumed in the magnetohydrodynamic (MHD) fluid model, normally applied to planetary magnetospheres, that the characteristic scale size is much greater than the Larmor radius and ion skin depth of the solar wind. In the case of M2P2, the size of the magnetic bubble is actually less than or comparable to the scale of these characteristic parameters. Therefore, a kinetic approach, which addresses the small-scale physical mechanisms, must be used. A two-component approach to determining a preliminary estimate of the momentum transfer to the plasma sail has been adopted. The first component is a self-consistent MHD simulation of the small-scale expansion phase of the magnetic bubble. The fluid treatment is valid to roughly 5 km from the source and the steady-state MHD solution at the 5 km boundary was then used as initial conditions for the hybrid simulation. The hybrid simulations showed that the forces delivered to the innermost regions of the plasma sail are considerably ( 10 times) smaller than the MHD counterpart, are dominated by the magnetic field pressure gradient, and are directed primarily in the transverse direction.

  9. Sailing through Leadership Theory

    ERIC Educational Resources Information Center

    Northup, Kimberly R.

    2006-01-01

    The University of Tampa's Leadership and Sailing program introduces students to leadership and sailing simultaneously by situating their learning about leadership in the context of sailing. By combining outdoor adventure and leadership training, the program is designed to help students learn the basic components of a sailboat and operate the boat…

  10. Magnetic sails and interplanetary travel

    SciTech Connect

    Zubrin, R.M.; Andrews, D.G.

    1989-01-01

    A new concept, the magnetic sail, or 'magsail' is proposed which propels spacecraft by using the magnetic field generated by a loop of superconducting cable to deflect interplanetary or interstellar plasma winds. The performance of such a device is evaluated using both a plasma particle model and a fluid model, and the results of a series of investigations are presented. It is found that a magsail sailing on the solar wind at a radius of one astronautical unit can attain accelerations on the order of 0.01 m/sec squared, much greater than that available from a conventional solar lightsail, and also greater than the acceleration due to the sun's gravitational attraction. A net tangential force, or 'lift' can also be generated. Lift to drag ratios of about 0.3 appear attainable. Equations are derived whereby orbital transfers using magsail propulsion can be calculated analytically.

  11. NASA Sails for the Stars

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Engineers at Marshall Space Flight Center's Interstellar Propulsion Research department are proposing different solutions to combustion propellants for future space travel. Pictured here is one alternative, the solar sail, depicted through an artist's concept. The idea is, once deployed, the sail will allow solar winds to propel a spacecraft away from Earth and towards its destination. This would allow a spacecraft to travel indefinitely without the need to refuel during its prolong journey. Thin reflective sails could be propelled through space by sunlight, microwave beams, or laser beams, just as the wind pushes sailboats on Earth. The sail will be the largest spacecraft ever built, sparning 440 yards, twice the diameter of the Louisiana Super Dome. Construction materials are being tested in a simulated space environment, where they are exposed to harsh conditions to test their performance and durability in extremely hot and cold temperatures. A leading candidate for the construction material is a carbon fiber material whose density is less than 1/10 ounce per square yard, the equivalent of flattening one raisin to the point that it covers a square yard. In space, the material would unfurl like a fan when it is deployed from an expendable rocket. Mankind's first venture outside of our solar system is proposed for launch in a 2010 timeframe. An interstellar probe, powered by the fastest spacecraft ever flown, will zoom toward the stars at 58 miles per second. It will cover the distance from New York to Los Angeles in less than a minute and will travel over 23 billion miles beyond the edge of the solar system.

  12. NanoSail - D Orbital and Attitude Dynamics

    NASA Technical Reports Server (NTRS)

    Heaton, Andrew F.; Faller, Brent F.; Katan, Chelsea K.

    2013-01-01

    NanoSail-D unfurled January 20th, 2011 and successfully demonstrated the deployment and deorbit capability of a solar sail in low Earth orbit. The orbit was strongly perturbed by solar radiation pressure, aerodynamic drag, and oblate gravity which were modeled using STK HPOP. A comparison of the ballistic coefficient history to the orbit parameters exhibits a strong relationship between orbital lighting, the decay rate of the mean semi-major axis and mean eccentricity. A similar comparison of mean solar area using the STK HPOP solar radiation pressure model exhibits a strong correlation of solar radiation pressure to mean eccentricity and mean argument of perigee. NanoSail-D was not actively controlled and had no capability on-board for attitude or orbit determination. To estimate attitude dynamics we created a 3-DOF attitude dynamics simulation that incorporated highly realistic estimates of perturbing forces into NanoSail-D torque models. By comparing the results of this simulation to the orbital behavior and ground observations of NanoSail-D, we conclude that there is a coupling between the orbit and attitude dynamics as well as establish approximate limits on the location of the NanoSail-D solar center of pressure. Both of these observations contribute valuable data for future solar sail designs and missions.

  13. Laser driven light sails: An examination of the possibilities for interstellar probes and other missions

    NASA Technical Reports Server (NTRS)

    Rather, J. D. G.; Zeiders, G. W.; Vogelsang, K. R.

    1976-01-01

    A theoretical discussion of high energy laser propelled light sails is presented. Selection of sail materials, interstellar drag forces, beam pointing, flight velocity, probe mass, and radiation shielding are among the factors discussed. Interstellar probe missions and colonization of the solar system via the light sail are considered.

  14. New age of sail

    SciTech Connect

    Robb, D.

    1982-08-01

    Wind power activities currently underway in the United States are discussed, in particular, the American conference on sail-equipped working vessel technology at Norfolk, Virginia. Lloyd Bergeson, founder of Wind Sail, and keynote speaker, discussed factory-built sail rigs which would be retrofitted aboard cargo ships and would function as a form of auxiliary propulsion for fuel conservation. An expedition from Sea World intends to build a 67 meter sailing research vessel and conduct a 3-1/2 year oceanographic research cruise. (MJF)

  15. Combining Electric and Sail Propulsion for Interplanetary Sample Return

    SciTech Connect

    Noble, Robert

    2003-02-04

    Fast sample return from the outer Solar System would open an entirely new avenue for space science, but the vast distances make this a daunting task. The achievable transit velocity and the need for extra propellant on the return trip limit the feasibility of returning extraterrestrial samples to Earth. To keep the mission duration short enough to be of interest, sample return from objects farther out in the Solar System requires increasingly higher velocities. High specific impulse, electric propulsion reduces the propellant required for the outbound and return trips, but decelerating the spacecraft at the inner Solar System from high velocity still involves a long, inward spiral trajectory. The use of solar sails to rapidly decelerate incoming sample capsules and eliminate propellant is explored in this paper. The sail is essentially a ''solar parachute'' used for braking at the end of the interplanetary return flight, permitting a higher transit speed and truncating the deceleration spiral. In this application the sail is relatively small and manageable since only the sample capsule and its sail are decelerated. A comparison is made between using all-electric propulsion versus combining electric propulsive acceleration with sail deceleration for sample return from the distances of Saturn, Uranus, and Pluto. Solar-sail braking dramatically reduces the return flight time by one-third or more compared to using electric rocket deceleration. To elucidate the technology requirements, wide ranges for both the loaded sail density and electric propulsion specific mass are considered in this initial parametric study.

  16. Electric sail missions to potentially hazardous asteroids

    NASA Astrophysics Data System (ADS)

    Quarta, Alessandro A.; Mengali, Giovanni

    2010-05-01

    Missions towards potentially hazardous asteroids require considerable propellant-mass consumption and complex flybys maneuvers with conventional propulsion systems. A very promising option is offered by an electric sail, an innovative propulsion concept, that uses the solar-wind dynamic pressure for generating a continuous and nearly radial thrust without the need for reaction mass. The aim of this paper is to investigate the performance of such a propulsion system for performing rendezvous missions towards all the currently known potentially hazardous asteroids, a total of 1025 missions. The problem is studied in an optimal framework by minimizing the total flight time. Assuming a canonical value of sail characteristic acceleration, we show that about 67% of the potentially hazardous asteroids may be reached within one year of mission time, with 137 rendezvous in the first six months. A detailed study towards asteroid 99942 Apophis is reported, and a comparison with the corresponding performance achievable with a flat solar sail is discussed.

  17. Drag and propulsive forces in electric sails with negative polarity

    NASA Astrophysics Data System (ADS)

    Sanchez-Torres, Antonio

    2016-02-01

    An electric solar sail (E-sail) is a recent propellantless propulsion concept for a direct exploration of the Solar System. An E-sail consists of a set of bare, conductive tethers at high positive/negative bias, prone to extract solar wind momentum by Coulomb deflection of protons. Additionally, a negatively biased E-sail has been proposed as a concept for de-orbiting space debris with drag forces produced in Low Earth Orbit (LEO). The present work focuses on the negative-bias case with a sheath that must be correctly modeled for a flowing plasma ambient. Ion scattering within the sheath and the resulting force are determined for several plasma conditions. Since the plasma flow does reduce the effective range for the ion scattering within the sheath, the resulting force is then reduced. Tethers at very high negative bias should be required for extremely high plasma flow.

  18. Les Johnson Views Interstellar Sail Material

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Engineers at Marshall Space Flight Center's (MSFC) Interstellar Propulsion Research department are proposing different solutions to combustion propellants for future space travel. One alternative being tested is the solar sail. The idea is, once deployed, the sail will allow solar winds to propel a spacecraft away from Earth and towards its destination. This would allow a spacecraft to travel indefinitely without the need to refuel during its ong journey. Thin reflective sails could be propelled through space by sunlight, microwave beams, or laser beams, just as the wind pushes sailboats on Earth. The sail will be the largest spacecraft ever built, sparning 440 yards, twice the diameter of the Louisiana Super Dome. Construction materials are being tested in a simulated space environment, where they are exposed to harsh conditions to test their performance and durability in extremely hot and cold temperatures. A leading candidate for the construction material is a carbon fiber material whose density is less than 1/10 ounce per square yard, the equivalent of flattening one raisin to the point that it covers a square yard. In space, the material would unfurl like a fan when it is deployed from an expendable rocket. This photo shows Les Johnson, manager of MSFC's Interstellar Propulsion Research Center holding the rigid, lightweight carbon fiber. An artist's concept of the sail is on the right. Mankind's first venture outside of our solar system is proposed for launch in a 2010 timeframe. An interstellar probe, powered by the fastest spacecraft ever flown, will zoom toward the stars at 58 miles per second. It will cover the distance from New York to Los Angeles in less than a minute and will travel over 23 billion miles beyond the edge of the solar system.

  19. Thrust Measurement of Pure Magnetic Sail

    NASA Astrophysics Data System (ADS)

    Ueno, Kazuma; Kimura, Toshiyuki; Ayabe, Tomohiro; Funaki, Ikkoh; Yamakawa, Hiroshi; Horisawa, Hideyuki

    A Pure Magnetic Sail is a deep space propulsion system consisting of a coil mounted on a spacecraft. In order to predict the thrust characteristics of a Pure Magnetic Sail in space, thrust measurement and magnetic field measurement were conducted using a scale model in a laboratory. To simulate the solar wind, a magnetoplasmadynamic arcjet provides a high density (2×1019 m-3) and high velocity (47 km/s) plasma flow that impinges on a 20-turn 25-mm-radius coil simulating a Pure Magnetic Sail. When the magnetic cavity size of the scale model (L) is increased from 0.12 to 0.17 m, the thrust increases from 0.47 to 0.92 N. Scaling up, this experiment corresponds to a 300-km diameter Pure Magnetic Sail in space. The thrust also depends on the coil tilt angle, which is the angle between the direction of the solar wind flow and the coil axis. The maximum thrust of 1.5 N is obtained for a tilt angle of 90 degrees.

  20. Numerical Analysis of Magnetic Sail Spacecraft

    SciTech Connect

    Sasaki, Daisuke; Yamakawa, Hiroshi; Usui, Hideyuki; Funaki, Ikkoh; Kojima, Hirotsugu

    2008-12-31

    To capture the kinetic energy of the solar wind by creating a large magnetosphere around the spacecraft, magneto-plasma sail injects a plasma jet into a strong magnetic field produced by an electromagnet onboard the spacecraft. The aim of this paper is to investigate the effect of the IMF (interplanetary magnetic field) on the magnetosphere of magneto-plasma sail. First, using an axi-symmetric two-dimensional MHD code, we numerically confirm the magnetic field inflation, and the formation of a magnetosphere by the interaction between the solar wind and the magnetic field. The expansion of an artificial magnetosphere by the plasma injection is then simulated, and we show that the magnetosphere is formed by the interaction between the solar wind and the magnetic field expanded by the plasma jet from the spacecraft. This simulation indicates the size of the artificial magnetosphere becomes smaller when applying the IMF.

  1. Microparticle impact calibration of the Arrayed Large-Area Dust Detectors in INterplanetary space (ALADDIN) onboard the solar power sail demonstrator IKAROS

    NASA Astrophysics Data System (ADS)

    Hirai, Takayuki; Cole, Michael J.; Fujii, Masayuki; Hasegawa, Sunao; Iwai, Takeo; Kobayashi, Masanori; Srama, Ralf; Yano, Hajime

    2014-10-01

    The Arrayed Large-Area Dust Detectors in INterplanetary space (ALADDIN) is an array of polyvinylidene fluoride (PVDF) based dust detectors aboard the solar power sail demonstrator named IKAROS (Interplanetary Kite-craft Accelerated by Radiation Of the Sun). The total sensor area of ALADDIN (0.54 m2) is the world's largest among the past PVDF-based dust detectors. IKAROS was launched in May 2010 and then ALADDIN measured cosmic dust impacts for 16 months while orbiting around between 0.7 and 1.1 AU. The main scientific objective of ALADDIN is to reveal number density of ≥10-μm-sized dust in the zodiacal cloud with much higher time-space resolution than that achieved by any past in-situ measurements. The distribution of ≥10-μm-sized dust can be also observed mainly with the light scattering by optical instruments. This paper gives the scientific objectives, the instrumental description, and the results of microparticle impact calibration of ALADDIN conducted in ground laboratories. For the calibration tests we used Van de Graaf accelerators (VdG), two-stage light gas guns (LGG), and a nano-second pulsed Nd:YAG laser (nsPL). Through these experiments, we obtained depolarization charge signal caused by hypervelocity impacts or laser irradiation using the flight spare of 20-μm-thick PVDF sensor and the electronics box of ALADDIN. In the VdG experiment we accelerated iron, carbon, and silver microparticles at 1-30 km/s, while in the LGG experiment we performed to shoot 100's-μm-sized particles of soda-lime glass and stainless steel at 3-7 km/s as single projectile. For interpolation to ≥10-μm size, we irradiated infrared laser at the energy of 15-20 mJ directly onto the PVDF sensor. From the signal analysis, we developed a calibration law for estimation of masses of impacted dust particles. The dynamic range of ALADDIN corresponds from 9×10-14 kg to 2×10-10 kg (4-56 μm in diameter at density of 2.0 g/cm3) at the expected impact velocity of 10 km/s at 1 AU

  2. Sails, Wind and Water.

    ERIC Educational Resources Information Center

    Hubbard, Guy

    1999-01-01

    Discusses maritime paintings addressing such topics as why artists are attracted to sailing vessels and the content of the paintings. Includes reproductions of paintings by Edward Hopper, John H. B. Everett, Lyonel Feininger, and Willem van de Velde the Younger. Selects works to help students realize that maritime art is quite varied. (CMK)

  3. Sailing to the Colonies.

    ERIC Educational Resources Information Center

    Carter, Dorothy S.

    1990-01-01

    Presents a class activity designed to foster an understanding of rules, develop analytical skills, and introduce students to early colonial history. Divides the class into groups who are sailing to the New World, and presents them with ethical and practical problems to be solved on board the ship. (RW)

  4. Construction of optimum controls and trajectories of motion of the center of masses of a spacecraft equipped with the solar sail and low-thrust engine, using quaternions and Kustaanheimo-Stiefel variables

    NASA Astrophysics Data System (ADS)

    Sapunkov, Ya. G.; Chelnokov, Yu. N.

    2014-11-01

    The problem of optimum rendezvous of a controllable spacecraft (SC) with an uncontrollable spacecraft, moving over a Keplerian elliptic orbit in the gravitational field of the Sun, is considered. Control of the SC is performed using a solar sail and low-thrust engine. For solving the problem, the regular quaternion equations of the two-body problem with the Kustaanheimo-Stiefel variables and the Pontryagin maximum principle are used. The combined integral quality functional, which characterizes energy consumption for controllable SC transition from an initial to final state and the time spent for this transition, is used as a minimized functional. The differential boundary-value optimization problems are formulated, and their first integrals are found. Examples of numerical solution of problems are presented. The paper develops the application [1-6] of quaternion regular equations with the Kustaanheimo-Stiefel variables in the space flight mechanics.

  5. Fast E-sail Uranus entry probe mission

    NASA Astrophysics Data System (ADS)

    Janhunen, Pekka; Lebreton, Jean-Pierre; Merikallio, Sini; Paton, Mark; Mengali, Giovanni; Quarta, Alessandro A.

    2014-12-01

    The electric solar wind sail is a novel propellantless space propulsion concept. According to numerical estimates, the electric solar wind sail can produce a large total impulse per propulsion system mass. Here we consider using a 0.5 N electric solar wind sail for boosting a 550 kg spacecraft to Uranus in less than 6 years. The spacecraft is a stack consisting of the electric solar wind sail module which is jettisoned roughly at Saturn distance, a carrier module and a probe for Uranus atmospheric entry. The carrier module has a chemical propulsion ability for orbital corrections and it uses its antenna for picking up the probe's data transmission and later relaying it to Earth. The scientific output of the mission is similar to what the Galileo Probe did at Jupiter. Measurements of the chemical and isotope composition of the Uranian atmosphere can give key constraints to different formation theories of the Solar System. A similar method could also be applied to other giant planets and Titan by using a fleet of more or less identical probes.

  6. Electric Sail Propulsion for Exploring Nearby Interstellar Space

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Wiegmann, Bruce; Bangham, Mike

    2015-01-01

    An Electric Sail is a revolutionary propellant-less propulsion system that is ideal for deep space missions to the outer planets, the Heliopause, and beyond. It is revolutionary in that it uses momentum exchange with the hypersonic solar wind to propel a spacecraft within the heliosphere. The momentum exchange is affected by the deflection of charged solar wind particles by an array of electrically biased wires that extend outward up to 30 km from a slowly rotating spacecraft. A high-voltage, positive bias on the wires, which are oriented normal to the solar wind flow, deflects the streaming protons, resulting in a reaction force on the wires that is also directed radially away from the sun. Over a period of months, this small force can accelerate the spacecraft to enormous speeds-on the order of 100-150 km/s (approximately 20 to 30 AU/yr). Unlike solar sails, Electric Sails do not rely on a fixed area to produce thrust. In fact, as they move away from the Sun and solar wind pressure decreases, the area for solar proton momentum transfer becomes larger, increasing system efficiency. As a result, thrust decreases at ˜1/r**(7/6) instead of the ˜1/r**2 rate typical for solar sails. The net effect is that an increased radial range of operation, together with increased thrust, both contribute to higher velocities and shorter total trip times to distant destinations. The MSFC Advanced Concepts Office (ACO) was awarded a Phase II NASA Innovative Advanced Concepts (NIAC) study to mature the technology for possible future demonstration and implementation. Preliminary results indicate that the physics of the system is viable and that a spacecraft propelled by an Electric Sail could reach the Heliopause in less than 15 years - and could be developed within a decade.

  7. Inside NanoSail-D: A Tiny Satellite with Big Ideas

    NASA Technical Reports Server (NTRS)

    Alhorn, Dean C.; Agasid, Elwood; Casas, Joseph; Adams, Charles; O'Brien, Sue; Laue, Greg; Kitts, Chris

    2011-01-01

    "Small But Mighty" certainly describes the NanoSail-D experiment and mission. Its unique goals and designs were simple, but the implications of this technology are far reaching. From a tiny 3U CubeSat, NanoSail-D deployed a 10 square meter solar sail. This was the first sail vehicle to orbit the earth and was only the second time a sail was unfurled in space. The NanoSail-D team included: two NASA centers, Marshall and Ames, the universities of Alabama in Huntsville and Santa Clara in California, the Air Force Research Laboratory and many contractors including NeXolve, Gray Research and several others. The collaborative nature was imperative to the success of this project. In addition, the Army Space and Missile Defense Command, the Von Braun Center for Science and Innovation and Dynetics Inc. jointly sponsored the NanoSail-D project. This paper presents in-depth insight into the NanoSail-D development. Its design was a combination of left over space hardware coupled with cutting edge technology. Since this NanoSail-D mission was different from the first, several modifications were necessary for the second NanoSail-D unit. Unforeseen problems arose during refurbishment of the second unit and the team had to overcome these obstacles. Simple interfaces, clear responsibilities and division of effort allowed the team members to work independently on the common goal. This endeavor formed working relationships lasting well beyond the end of this mission. NanoSail-D pushed the technology envelop with future applications for all classes of satellites. NanoSail-D is truly a small but mighty satellite, which may cast a very big shadow for years to come.

  8. 'Light Sail' Acceleration Reexamined

    SciTech Connect

    Macchi, Andrea; Veghini, Silvia; Pegoraro, Francesco

    2009-08-21

    The dynamics of the acceleration of ultrathin foil targets by the radiation pressure of superintense, circularly polarized laser pulses is investigated by analytical modeling and particle-in-cell simulations. By addressing self-induced transparency and charge separation effects, it is shown that for 'optimal' values of the foil thickness only a thin layer at the rear side is accelerated by radiation pressure. The simple 'light sail' model gives a good estimate of the energy per nucleon, but overestimates the conversion efficiency of laser energy into monoenergetic ions.

  9. Electric sail control mode for amplified transverse thrust

    NASA Astrophysics Data System (ADS)

    Toivanen, P.; Janhunen, P.; Envall, J.

    2015-01-01

    The electric solar wind sail produces thrust by centrifugally spanned high voltage tethers interacting with the solar wind protons. The sail attitude can be controlled and attitude maneuvers are possible by tether voltage modulation synchronous with the sail rotation. Especially, the sail can be inclined with respect to the solar wind direction to obtain transverse thrust to change the osculating orbit angular momentum. Such an inclination has to be maintained by a continual control voltage modulation. Consequently, the tether voltage available for the thrust is less than the maximum voltage provided by the power system. Using a spherical pendulum as a model for a single rotating tether, we derive analytical estimations for the control efficiency for two separate sail control modes. One is a continuous control modulation that corresponds to strictly planar tether tip motion. The other is an on-off modulation with the tether tip moving along a closed loop on a saddle surface. The novel on-off mode is introduced here to both amplify the transverse thrust and reduce the power consumption. During the rotation cycle, the maximum voltage is applied to the tether only over two thrusting arcs when most of the transverse thrust is produced. In addition to the transverse thrust, we obtain the thrusting angle and electric power consumption for the two control modes. It is concluded that while the thrusting angle is about half of the sail inclination for the continuous modulation it approximately equals to the inclination angle for the on-off modulation. The efficiency of the on-off mode is emphasized when power consumption is considered, and the on-off mode can be used to improve the propulsive acceleration through the reduced power system mass.

  10. Aerodynamics of Unsteady Sailing Kinetics

    NASA Astrophysics Data System (ADS)

    Keil, Colin; Schutt, Riley; Borshoff, Jennifer; Alley, Philip; de Zegher, Maximilien; Williamson, Chk

    2015-11-01

    In small sailboats, the bodyweight of the sailor is proportionately large enough to induce significant unsteady motion of the boat and sail. Sailors use a variety of kinetic techniques to create sail dynamics which can provide an increment in thrust, thereby increasing the boatspeed. In this study, we experimentally investigate the unsteady aerodynamics associated with two techniques, ``upwind leech flicking'' and ``downwind S-turns''. We explore the dynamics of an Olympic class Laser sailboat equipped with a GPS, IMU, wind sensor, and camera array, sailed expertly by a member of the US Olympic team. The velocity heading of a sailing boat is oriented at an apparent wind angle to the flow. In contrast to classic flapping propulsion, the heaving of the sail section is not perpendicular to the sail's motion through the air. This leads to heave with components parallel and perpendicular to the incident flow. The characteristic motion is recreated in a towing tank where the vortex structures generated by a representative 2-D sail section are observed using Particle Image Velocimetry and the measurement of thrust and lift forces. Amongst other results, we show that the increase in driving force, generated due to heave, is larger for greater apparent wind angles.

  11. Physical requirements in Olympic sailing.

    PubMed

    Bojsen-Møller, J; Larsson, B; Aagaard, P

    2015-01-01

    Physical fitness and muscular strength are important performance parameters in Olympic sailing although their relative importance changes between classes. The Olympic format consists of eight yacht types combined into 10 so-called events with total 15 sailors (male and female) in a complete national Olympic delegation. The yachts have different requirements with respect to handling, and moreover, each sailor plays a specific role when sailing. Therefore physical demands remain heterogeneous for Olympic sailors. Previous studies have mainly examined sailors where 'hiking' (the task of leaning over the side of the yacht to increase righting moment) is the primary requirement. Other than the ability to sustain prolonged quasi-isometric contractions, hiking seems to require significant maximal muscle strength especially in knee extensors, hip flexors and abdominal and lower back muscles. Another group of studies has investigated boardsailing and provided evidence to show that windsurfing requires very high aerobic and anaerobic capacity. Although data exist on other types of sailors, the information is limited, and moreover the profile of the Olympic events has changed markedly over the last few years to involve more agile, fast and spectacular yachts. The change of events in Olympic sailing has likely added to physical requirements; however, data on sailors in the modern-type yachts are scarce. The present paper describes the recent developments in Olympic sailing with respect to yacht types, and reviews the existing knowledge on physical requirements in modern Olympic sailing. Finally, recommendations for future research in sailing are given. PMID:25232650

  12. Scale-model Experiment of Magnetoplasma Sail for Future Deep Space Missions

    NASA Astrophysics Data System (ADS)

    Funaki, Ikkoh; Yamakawa, Hiroshi; Ueno, Kazuma; Kimura, Toshiyuki; Ayabe, Tomohiro; Horisawa, Hideyuki

    2008-04-01

    When Magnetic sail (MagSail) spacecraft is operated in space, the supersonic solar wind plasma flow is blocked by an artificially produced magnetic cavity to accelerate the spacecraft in the direction leaving the Sun. To evaluate the momentum transferring process from the solar wind to the coil onboard the MagSail spacecraft, we arranged a laboratory experiment of MagSail spacecraft. Based on scaling considerations, a solenoidal coil was immersed into the plasma flow from a magnetoplasmadynamic arcjet in a quasi-steady mode of about 1 ms duration. In this setup, it is confirmed that a magnetic cavity, which is similar to that of the geomagnetic field, was formed around the coil to produce thrust in the ion Larmor scale interaction. Also, the controllability of magnetic cavity size by a plasma jet from inside the coil of MagSail is demonstrated, although the thrust characteristic of the MagSail with plasma jet, which is so called plasma sail, is to be clarified in our next step.

  13. Boltzmann electron PIC simulation of the E-sail effect

    NASA Astrophysics Data System (ADS)

    Janhunen, P.

    2015-12-01

    The solar wind electric sail (E-sail) is a planned in-space propulsion device that uses the natural solar wind momentum flux for spacecraft propulsion with the help of long, charged, centrifugally stretched tethers. The problem of accurately predicting the E-sail thrust is still somewhat open, however, due to a possible electron population trapped by the tether. Here we develop a new type of particle-in-cell (PIC) simulation for predicting E-sail thrust. In the new simulation, electrons are modelled as a fluid, hence resembling hybrid simulation, but in contrast to normal hybrid simulation, the Poisson equation is used as in normal PIC to calculate the self-consistent electrostatic field. For electron-repulsive parts of the potential, the Boltzmann relation is used. For electron-attractive parts of the potential we employ a power law which contains a parameter that can be used to control the number of trapped electrons. We perform a set of runs varying the parameter and select the one with the smallest number of trapped electrons which still behaves in a physically meaningful way in the sense of producing not more than one solar wind ion deflection shock upstream of the tether. By this prescription we obtain thrust per tether length values that are in line with earlier estimates, although somewhat smaller. We conclude that the Boltzmann PIC simulation is a new tool for simulating the E-sail thrust. This tool enables us to calculate solutions rapidly and allows to easily study different scenarios for trapped electrons.

  14. Sailing: An Introduction to the Wonders of Sailing for Blind and Physically Handicapped Individuals.

    ERIC Educational Resources Information Center

    Cylke, Frank Kurt, Ed.

    This annotated bilbiography of materials focuses on sailing. Two articles are presented in full. They are: "Sailing in Tall Ships" (Tony Elbourn) and "Sailing Blind" (Charles E. Leonard). Each article tells the true story of a blind person's experience with sailing. Material listings are presented for adults under the following categories:…

  15. SailSpy: a vision system for yacht sail shape measurement

    NASA Astrophysics Data System (ADS)

    Olsson, Olof J.; Power, P. Wayne; Bowman, Chris C.; Palmer, G. Terry; Clist, Roger S.

    1992-11-01

    SailSpy is a real-time vision system which we have developed for automatically measuring sail shapes and masthead rotation on racing yachts. Versions have been used by the New Zealand team in two America's Cup challenges in 1988 and 1992. SailSpy uses four miniature video cameras mounted at the top of the mast to provide views of the headsail and mainsail on either tack. The cameras are connected to the SailSpy computer below deck using lightweight cables mounted inside the mast. Images received from the cameras are automatically analyzed by the SailSpy computer, and sail shape and mast rotation parameters are calculated. The sail shape parameters are calculated by recognizing sail markers (ellipses) that have been attached to the sails, and the mast rotation parameters by recognizing deck markers painted on the deck. This paper describes the SailSpy system and some of the vision algorithms used.

  16. Sailing and sports medicine: a literature review

    PubMed Central

    Allen, J B; De Jong, M R

    2006-01-01

    Sailing medicine has been mainly addressed by healthcare professionals who happen to sail. Although there has been an increase in the number of studies of various aspects of sailing over the last 15 years, efforts to advance evidence based knowledge of sailing and sports medicine face unique obstacles. Recent interest in research by groups such as Olympic and America's Cup teams has produced beneficial changes. PMID:16547146

  17. 46 CFR 116.330 - Sailing vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Sailing vessels. 116.330 Section 116.330 Shipping COAST... Structure § 116.330 Sailing vessels. The design, materials, and construction of masts, posts, yards, booms, bowsprits, and standing rigging on a sailing vessel must be suitable for the intended service. The...

  18. 46 CFR 116.330 - Sailing vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Sailing vessels. 116.330 Section 116.330 Shipping COAST... Structure § 116.330 Sailing vessels. The design, materials, and construction of masts, posts, yards, booms, bowsprits, and standing rigging on a sailing vessel must be suitable for the intended service. The...

  19. 46 CFR 15.725 - Sailing short.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Sailing short. 15.725 Section 15.725 Shipping COAST... Limitations and Qualifying Factors § 15.725 Sailing short. Whenever a vessel is deprived of the service of a... vessel is sufficiently manned for the voyage. A report of sailing short must be filed in writing with...

  20. 46 CFR 15.725 - Sailing short.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Sailing short. 15.725 Section 15.725 Shipping COAST... Limitations and Qualifying Factors § 15.725 Sailing short. Whenever a vessel is deprived of the service of a... vessel is sufficiently manned for the voyage. A report of sailing short must be filed in writing with...

  1. 46 CFR 116.330 - Sailing vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Sailing vessels. 116.330 Section 116.330 Shipping COAST... Structure § 116.330 Sailing vessels. The design, materials, and construction of masts, posts, yards, booms, bowsprits, and standing rigging on a sailing vessel must be suitable for the intended service. The...

  2. 46 CFR 15.725 - Sailing short.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Sailing short. 15.725 Section 15.725 Shipping COAST... Limitations and Qualifying Factors § 15.725 Sailing short. Whenever a vessel is deprived of the service of a... vessel is sufficiently manned for the voyage. A report of sailing short must be filed in writing with...

  3. 46 CFR 15.725 - Sailing short.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Sailing short. 15.725 Section 15.725 Shipping COAST... Limitations and Qualifying Factors § 15.725 Sailing short. Whenever a vessel is deprived of the service of a... vessel is sufficiently manned for the voyage. A report of sailing short must be filed in writing with...

  4. 46 CFR 177.330 - Sailing vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Sailing vessels. 177.330 Section 177.330 Shipping COAST...) CONSTRUCTION AND ARRANGEMENT Hull Structure § 177.330 Sailing vessels. The design, materials, and construction of masts, posts, yards, booms, bowsprits, and standing rigging on a sailing vessel must be...

  5. 46 CFR 116.330 - Sailing vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Sailing vessels. 116.330 Section 116.330 Shipping COAST... Structure § 116.330 Sailing vessels. The design, materials, and construction of masts, posts, yards, booms, bowsprits, and standing rigging on a sailing vessel must be suitable for the intended service. The...

  6. 46 CFR 116.330 - Sailing vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Sailing vessels. 116.330 Section 116.330 Shipping COAST... Structure § 116.330 Sailing vessels. The design, materials, and construction of masts, posts, yards, booms, bowsprits, and standing rigging on a sailing vessel must be suitable for the intended service. The...

  7. 46 CFR 177.330 - Sailing vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Sailing vessels. 177.330 Section 177.330 Shipping COAST...) CONSTRUCTION AND ARRANGEMENT Hull Structure § 177.330 Sailing vessels. The design, materials, and construction of masts, posts, yards, booms, bowsprits, and standing rigging on a sailing vessel must be...

  8. 46 CFR 15.725 - Sailing short.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Sailing short. 15.725 Section 15.725 Shipping COAST... Limitations and Qualifying Factors § 15.725 Sailing short. Whenever a vessel is deprived of the service of a... vessel is sufficiently manned for the voyage. A report of sailing short must be filed with the...

  9. SETI via Leakage from Light Sails in Exoplanetary Systems

    NASA Astrophysics Data System (ADS)

    Guillochon, James; Loeb, Abraham

    2015-10-01

    The primary challenge of rocket propulsion is the burden of needing to accelerate the spacecraft’s own fuel, resulting in only a logarithmic gain in maximum speed as propellant is added to the spacecraft. Light sails offer an attractive alternative in which fuel is not carried by the spacecraft, with acceleration being provided by an external source of light. By artificially illuminating the spacecraft with beamed radiation, speeds are only limited by the area of the sail, heat resistance of its material, and power use of the accelerating apparatus. In this paper, we show that leakage from a light sail propulsion apparatus in operation around a solar system analogue would be detectable. To demonstrate this, we model the launch and arrival of a microwave beam-driven light sail constructed for transit between planets in orbit around a single star, and find an optimal beam frequency on the order of tens of GHz. Leakage from these beams yields transients with flux densities of Jy and durations of tens of seconds at 100 pc. Because most travel within a planetary system would be conducted between the habitable worlds within that system, multiply transiting exoplanetary systems offer the greatest chance of detection, especially when the planets are in projected conjunction as viewed from Earth. If interplanetary travel via beam-driven light sails is commonly employed in our galaxy, this activity could be revealed by radio follow-up of nearby transiting exoplanetary systems. The expected signal properties define a new strategy in the search for extraterrestrial intelligence (SETI).

  10. Indicators of sailing performance in youth dinghy sailing.

    PubMed

    Callewaert, Margot; Boone, Jan; Celie, Bert; De Clercq, Dirk; Bourgois, Jan G

    2015-01-01

    This study aimed to determine indicators of sailing performance in 2 (age) groups of youth sailors by investigating the anthropometric, physical and motor coordination differences and factors discriminating between elite and non-elite male optimist sailors and young dynamic hikers. Anthropometric measurements from 23 optimist sailors (mean ± SD age = 12.3 ± 1.4 years) and 24 dynamic youth hikers (i.e. Laser 4.7, Laser radial and Europe sailors <18 years who have to sail the boat in a very dynamic manner, due to a high sailor to yacht weight ratio) (mean ± SD age = 16.5 ± 1.6 years) were conducted. They performed a physical fitness test battery (EUROFIT), motor coordination test battery (Körperkoordinationstest für Kinder) and the Bucket test. Both groups of sailors were divided into two subgroups (i.e. elites and non-elites) based on sailing expertise. The significant differences, taking biological maturation into account and factors discriminating between elite and non-elite optimist sailors and dynamic hikers were explored by means of multivariate analysis of covariance and discriminant analysis, respectively. The main results indicated that 100.0% of elite optimist sailors and 88.9% of elite dynamic hikers could be correctly classified by means of two motor coordination tests (i.e. side step and side jump) and Bucket test, respectively. As such, strength- and speed-oriented motor coordination and isometric knee-extension strength endurance can be identified as indicators of sailing performance in young optimist and dynamic youth sailors, respectively. Therefore, we emphasise the importance of motor coordination skill training in optimist sailors (<15 years) and maximum strength training later on (>15 years) in order to increase their isometric knee-extension strength endurance. PMID:24720497

  11. The Speed Limit for Graphene Interstellar Photon Sails

    NASA Astrophysics Data System (ADS)

    Matloff, G. L.

    Graphene, a two-dimensional carbon molecular monolayer, has properties that may render it very useful for application to interstellar solar photon sailing. These include very low areal mass thickness, high melting point, high impermeability to fill gas in a hollow-body sail configuration, and high tensile strength. With appropriate "additives," graphene has a finite reflectance to sunlight and sunlight absorption of 40% or higher. Here, we evaluate the probably unobtainable ultimate performance of this material. It is assumed that absorption can be raised to 95% and reflectance to 5% without increasing areal mass thickness over the graphene value of 7.4 * 10-7 kg/m2. It is also assumed that the only limitations on perihelion distance are thermal; spaceenvironment effects and possible variation of optical properties with temperature are ignored. To evaluate ultimate performance, an initially parabolic solar orbit with a ~0.01 AU perihelion is assumed. A thin-film probe with the payload integrated with the sail can achieve an interstellar cruise velocity of ~0.046c in the highly unlikely event that accelerations of ~6,000g can be tolerated. Regardless of the final velocity, graphene "Starwisps" might see application in interstellar particle-beam propulsion.

  12. Natural and sail-displaced doubly-symmetric Lagrange point orbits for polar coverage

    NASA Astrophysics Data System (ADS)

    Ceriotti, Matteo; McInnes, Colin R.

    2012-10-01

    This paper proposes the use of doubly-symmetric, eight-shaped orbits in the circular restricted three-body problem for continuous coverage of the high-latitude regions of the Earth. These orbits, for a range of amplitudes, spend a large fraction of their period above either pole of the Earth. It is shown that they complement Sun-synchronous polar and highly eccentric Molniya orbits, and present a possible alternative to low thrust pole-sitter orbits. Both natural and solar-sail displaced orbits are considered. Continuation methods are described and used to generate families of these orbits. Starting from ballistic orbits, other families are created either by increasing the sail lightness number, varying the period or changing the sail attitude. Some representative orbits are then chosen to demonstrate the visibility of high-latitude regions throughout the year. A stability analysis is also performed, revealing that the orbits are unstable: it is found that for particular orbits, a solar sail can reduce their instability. A preliminary design of a linear quadratic regulator is presented as a solution to stabilize the system by using the solar sail only. Finally, invariant manifolds are exploited to identify orbits that present the opportunity of a ballistic transfer directly from low Earth orbit.

  13. 1993 triggered lighnting test program: Environments within 20 meters of the lighting channel and small area temporary protection concepts

    SciTech Connect

    Fisher, R.J.; Schnetzer, G.H.

    1994-03-01

    Vertical electric fields, azimuthal magnetic fields, and earth step potentials at ground level have been measured at 10 and 20 meters from the base of triggered lightning flashes. For incident stroke peak currents in the range of 4.4 to 29 kA, vertical electric field change amplitudes as high as 210 kV/m were observed at 10 m, with rise times of the order of a few microseconds. Magnetic fields were found to follow Ampere`s law closely at both 10 and 20 m. Earth step potentials measured over a 0.5-m radial distance at the 10-m and 20m stations were linear with and had the same waveforms as the stroke currents. The step voltages exhibited a l/r distance dependence between the two measurement distances. A model that incorporates the presence of a thin surface layer, due to rain water saturation, of much higher conductivity than the bulk of the underlying earth is proposed to explain the observed behavior. Tests were also carried out to evaluate the effectiveness of several concepts for protecting a small exposed object, such as a piece of ordnance at the site of a transportation accident, from either a direct strike or from the indirect effects of electromagnetic fields produced by a nearby lightning flash to ground. Photographs of the occurrence of significant radial filamentary arcing along the surface of the ground from the strike points were acquired. This type of arcing, with a maximum radial extent of at least 20 m, was observed on six of seven of triggered flashes and on all strokes of 15-kA peak amplitude or higher.

  14. Time step size and model stiffness in the simulated slew of a tow of square sails

    NASA Astrophysics Data System (ADS)

    Greschik, Gyula

    2011-12-01

    In order to assess space tow solar sail stability and control feasibility, slew simulations are performed for a simplified but dynamically representative km-class tow-like sail of sixteen 25 m square units (10,000 m 2 total area and 110 kg gross mass) with a 250 kg payload. It is seen that, for the dimensions considered, the space tow concept is structurally sound and its control is feasible. While observed instabilities are identified as numeric in nature and are eliminated accordingly, their very occurrence highlights the need for a refinement of the model for future studies. The analyses are carried out with custom software implementing non-standard implicit-iterative time integration with innovative elements. A new damping model, specifically tailored for the analysis of truly gossamer systems such as solar sails, is also proposed.

  15. 33 CFR 83.12 - Sailing vessels (Rule 12).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Sailing vessels (Rule 12). 83.12... NAVIGATION RULES RULES Steering and Sailing Rules Conduct of Vessels in Sight of One Another § 83.12 Sailing vessels (Rule 12). (a) Keeping out of the way. When two sailing vessels are approaching one another, so...

  16. 33 CFR 83.12 - Sailing vessels (Rule 12).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Sailing vessels (Rule 12). 83.12... NAVIGATION RULES RULES Steering and Sailing Rules Conduct of Vessels in Sight of One Another § 83.12 Sailing vessels (Rule 12). (a) Keeping out of the way. When two sailing vessels are approaching one another, so...

  17. Sustained Manned Mars Presence Enabled by E-sail Technology and Asteroid Water Mining

    NASA Astrophysics Data System (ADS)

    Janhunen, Pekka; Merikallio, Sini; Toivanen, Petri; Envall, M. Jouni

    The Electric Solar Wind Sail (E-sail) can produce 0.5-1 N of inexhaustible and controllable propellantless thrust [1]. The E-sail is based on electrostatic Coulomb interaction between charged thin tethers and solar wind ions. It was invented in 2006, was developed to TRL 4-5 in 2011-2013 with ESAIL FP7 project (http://www.electric-sailing.fi/fp7) and a CubeSat small-scale flight test is in course (ESTCube-1). The E-sail provides a flexible and efficient way of moving 0-2 tonne sized cargo payloads in the solar system without consuming propellant. Given the E-sail, one could use it to make manned exploration of the solar system more affordable by combining it with asteroid water mining. One first sends a miner spacecraft to an asteroid or asteroids, either by E-sail or traditional means. Many asteroids are known to contain water and liberating it only requires heating the material one piece at a time in a leak tight container. About 2 tonne miner can produce 50 tonnes of water per year which is sufficient to sustain continuous manned traffic between Earth and Mars. If the ice-bearing asteroid resides roughly at Mars distance, it takes 3 years for a 0.7 N E-sailer to transport a 10 tonne water/ice payload to Mars orbit or Earth C3 orbit. Thus one needs a fleet of 15 E-sail transport spacecraft plus replacements to ferry 50 tonnes of water yearly to Earth C3 (1/3) and Mars orbit (2/3). The mass of one transporter is 300 kg [2]. One needs to launch max 1.5 tonne mass of new E-sail transporters per year and in practice much less since it is simple to reuse them. This infrastructure is enough to supply 17 tonnes of water yearly at Earth C3 and 33 tonnes in Mars orbit. Orbital water can be used by manned exploration in three ways: (1) for potable water and for making oxygen, (2) for radiation shielding, (3) for LH2/LOX propellant. Up to 75 % of the wet mass of the manned module could be water (50 % propellant and 25 % radiation shield water). On top of this the total mass

  18. Numerical analysis and design of upwind sails

    NASA Astrophysics Data System (ADS)

    Shankaran, Sriram

    The use of computational techniques that solve the Euler or the Navier-Stokes equations are increasingly being used by competing syndicates in races like the Americas Cup. For sail configurations, this desire stems from a need to understand the influence of the mast on the boundary layer and pressure distribution on the main sail, the effect of camber and planform variations of the sails on the driving and heeling force produced by them and the interaction of the boundary layer profile of the air over the surface of the water and the gap between the boom and the deck on the performance of the sail. Traditionally, experimental methods along with potential flow solvers have been widely used to quantify these effects. While these approaches are invaluable either for validation purposes or during the early stages of design, the potential advantages of high fidelity computational methods makes them attractive candidates during the later stages of the design process. The aim of this study is to develop and validate numerical methods that solve the inviscid field equations (Euler) to simulate and design upwind sails. The three dimensional compressible Euler equations are modified using the idea of artificial compressibility and discretized on unstructured tetrahedral grids to provide estimates of lift and drag for upwind sail configurations. Convergence acceleration techniques like multigrid and residual averaging are used along with parallel computing platforms to enable these simulations to be performed in a few minutes. To account for the elastic nature of the sail cloth, this flow solver was coupled to NASTRAN to provide estimates of the deflections caused by the pressure loading. The results of this aeroclastic simulation, showed that the major effect of the sail elasticity; was in altering the pressure distribution around the leading edge of the head and the main sail. Adjoint based design methods were developed next and were used to induce changes to the camber

  19. Coupled attitude-orbit dynamics and control for an electric sail in a heliocentric transfer mission.

    PubMed

    Huo, Mingying; Zhao, Jun; Xie, Shaobiao; Qi, Naiming

    2015-01-01

    The paper discusses the coupled attitude-orbit dynamics and control of an electric-sail-based spacecraft in a heliocentric transfer mission. The mathematical model characterizing the propulsive thrust is first described as a function of the orbital radius and the sail angle. Since the solar wind dynamic pressure acceleration is induced by the sail attitude, the orbital and attitude dynamics of electric sails are coupled, and are discussed together. Based on the coupled equations, the flight control is investigated, wherein the orbital control is studied in an optimal framework via a hybrid optimization method and the attitude controller is designed based on feedback linearization control. To verify the effectiveness of the proposed control strategy, a transfer problem from Earth to Mars is considered. The numerical results show that the proposed strategy can control the coupled system very well, and a small control torque can control both the attitude and orbit. The study in this paper will contribute to the theory study and application of electric sail. PMID:25950179

  20. Coupled Attitude-Orbit Dynamics and Control for an Electric Sail in a Heliocentric Transfer Mission

    PubMed Central

    Huo, Mingying; Zhao, Jun; Xie, Shaobiao; Qi, Naiming

    2015-01-01

    The paper discusses the coupled attitude-orbit dynamics and control of an electric-sail-based spacecraft in a heliocentric transfer mission. The mathematical model characterizing the propulsive thrust is first described as a function of the orbital radius and the sail angle. Since the solar wind dynamic pressure acceleration is induced by the sail attitude, the orbital and attitude dynamics of electric sails are coupled, and are discussed together. Based on the coupled equations, the flight control is investigated, wherein the orbital control is studied in an optimal framework via a hybrid optimization method and the attitude controller is designed based on feedback linearization control. To verify the effectiveness of the proposed control strategy, a transfer problem from Earth to Mars is considered. The numerical results show that the proposed strategy can control the coupled system very well, and a small control torque can control both the attitude and orbit. The study in this paper will contribute to the theory study and application of electric sail. PMID:25950179

  1. 46 CFR 177.330 - Sailing vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... of masts, posts, yards, booms, bowsprits, and standing rigging on a sailing vessel must be suitable... calculations on the strength of the mast, post, yards, booms, bowsprits, and standing rigging to the...

  2. 46 CFR 177.330 - Sailing vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... of masts, posts, yards, booms, bowsprits, and standing rigging on a sailing vessel must be suitable... calculations on the strength of the mast, post, yards, booms, bowsprits, and standing rigging to the...

  3. 46 CFR 177.330 - Sailing vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... of masts, posts, yards, booms, bowsprits, and standing rigging on a sailing vessel must be suitable... calculations on the strength of the mast, post, yards, booms, bowsprits, and standing rigging to the...

  4. Set Your Water Program Full Sail.

    ERIC Educational Resources Information Center

    Farkas, Dick

    1989-01-01

    This article describes the community sailing program established by the Wilmette Park District, in suburban Chicago. This program, without losing money, provides affordable instruction and other services to beginning sailors of various ages. (IAH)

  5. Aerodynamics of high aspect-ratio sails

    NASA Astrophysics Data System (ADS)

    Crook, Andrew; Gerritsen, Margot

    2003-11-01

    Experiments studying the aerodynamics of a 25circular-arc sail section (representative of an AC gennaker cross-section) have been undertaken in the 7x10 ft tunnels at NASA-Ames and Georgia Tech. The aims of the study are to gain a deeper physical understanding of the flow past downwind sails at various angles of incidence and Reynolds numbers, and to create a comprehensive database for validation of numerical models and turbulence models used by the yacht research community and competitive sailing industry. The reason for testing a rectangular planform sail with no spanwise variation in twist or cross-section is to first provide a detailed understanding of the flow topology around generic sail sections. Currently, data of sufficient accuracy to be used for CFD validation are not available. 3D experiments with realistic sail planforms and twisted onset flow are planned for the future. Two models have been tested, one with an AR of 15 and constructed from steel and the other with an AR of 10 and constructed from carbon-fiber and foam. The latter model has pressure tappings, whilst the former was coated with PSP. Pressure distributions, surface flow visualization and PIV reveal the details of the changing flow patterns and separation types with varying angle of incidence.

  6. A Deweyian Framework for Youth Development in Experiential Education: Perspectives from Sail Training and Sailing Instruction

    ERIC Educational Resources Information Center

    Wojcikiewicz, Steven K.; Mural, Zachary B.

    2010-01-01

    In this piece, we put forth a Deweyian framework for youth development activities in outdoor and adventure education programs, and we show how such a framework may be exemplified by activities in sail training and sailing instruction. The paper begins with a discussion of the theoretical features of Deweyian educational experiences and makes…

  7. Isometric quadriceps strength determines sailing performance and neuromuscular fatigue during an upwind sailing emulation.

    PubMed

    Bourgois, Jan G; Callewaert, Margot; Celie, Bert; De Clercq, Dirk; Boone, Jan

    2016-01-01

    This study investigates the physiological responses to upwind sailing on a laser emulation ergometer and analyses the components of the physical profile that determine the physiological responses related to sailing level. Ten male high-level laser sailors performed an upwind sailing test, incremental cycling test and quadriceps strength test. During the upwind sailing test, heart rate (HR), oxygen uptake, ventilation, respiratory exchange ratio, rating of perceived exertion (RPE) and lactate concentration were measured, combined with near-infrared spectroscopy (NIRS) and electromyography (EMG) registration of the M. Vastus lateralis. Repeated measures ANOVA showed for the cardio-respiratory, metabolic and muscles responses (mean power frequency [MPF], root mean square [RMS], deoxy[Hb+Mb]) during the upwind sailing test an initial significant increase followed by a stabilisation, despite a constant increase in RPE. Stepwise regression analysis showed that better sailing level was for 46.5% predicted by lower MPF decrease. Lower MPF decrease was for 57.8% predicted by a higher maximal isometric quadriceps strength. In conclusion, this study indicates that higher sailing level was mainly determined by a lower rate of neuromuscular fatigue during the upwind sailing test (as indicated by MPF decrease). Additionally, the level of neuromuscular fatigue was mainly determined by higher maximal isometric quadriceps strength stressing the importance of resistance training in the planning of training. PMID:26323461

  8. Fundamentals of the Plasma Sail Concept: MHD and Kinetic Studies

    NASA Technical Reports Server (NTRS)

    Khazanov, G.; Delamere, P.; Kabin, K.; Linde, T. J.; Krivorutsky, E.

    2003-01-01

    The Mini-Magnetospheric Plasma Propulsion (M2P2), originally proposed by Winglee et al. [2000] predicts that a 15-km standoff distance (or 20-km cross-sectional dimension) of the magnetic bubble will provide for sufficient momentum transfer from the solar wind to accelerate a spacecraft to the unprecedented speeds of 50-80 km/s after an acceleration period of about three months. Such velocities will enable travel out of the solar system in period of about seven years-almost an order of magnitude improvement over present chemical based propulsion systems. However, for the parameters of the simulation of Winglee et al. [2000], a fluid model for the interaction of M2P2 with the solar wind is not valid. It is assumed in the MHD fluid model, normally applied to planetary magnetospheres, that the characteristic scale-size is much greater than the Larmor radius and ion skin depth of the solar wind. In the case of M2P2, the size of the magnetic bubble is actually less than or, comparable to, the scale of these characteristic parameters. Therefore, a kinetic approach, which addresses the small-scale physical mechanisms, must be used. We have adopted a two-component approach to determining a preliminary estimate of the momentum transfer to the plasma sail. The first component is a self-consistent MHD simulation of the small-scale expansion phase of the magnetic bubble. The fluid treatment is valid to roughly 5 km from the source and the steady-state MHD solution at the 5 km boundary was then used as initial conditions for the hybrid simulation. The hybrid simulations showed that the momentum transfer to the innermost regions of the plasma sail is negligible.

  9. 46 CFR 173.053 - Sailing school vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Sailing school vessels. 173.053 Section 173.053 Shipping... PERTAINING TO VESSEL USE School Ships § 173.053 Sailing school vessels. (a) In addition to the requirements in §§ 173.054 through 173.063, each sailing school vessel must comply with the provisions of...

  10. 46 CFR 173.053 - Sailing school vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Sailing school vessels. 173.053 Section 173.053 Shipping... PERTAINING TO VESSEL USE School Ships § 173.053 Sailing school vessels. (a) In addition to the requirements in §§ 173.054 through 173.063, each sailing school vessel must comply with the provisions of...

  11. 46 CFR 173.053 - Sailing school vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Sailing school vessels. 173.053 Section 173.053 Shipping... PERTAINING TO VESSEL USE School Ships § 173.053 Sailing school vessels. (a) In addition to the requirements in §§ 173.054 through 173.063, each sailing school vessel must comply with the provisions of...

  12. 46 CFR 173.053 - Sailing school vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Sailing school vessels. 173.053 Section 173.053 Shipping... PERTAINING TO VESSEL USE School Ships § 173.053 Sailing school vessels. (a) In addition to the requirements in §§ 173.054 through 173.063, each sailing school vessel must comply with the provisions of...

  13. 46 CFR 173.053 - Sailing school vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Sailing school vessels. 173.053 Section 173.053 Shipping... PERTAINING TO VESSEL USE School Ships § 173.053 Sailing school vessels. (a) In addition to the requirements in §§ 173.054 through 173.063, each sailing school vessel must comply with the provisions of...

  14. Rethinking Use of the OML Model in Electric Sail Development

    NASA Technical Reports Server (NTRS)

    Stone, Nobie H.

    2016-01-01

    In 1924, Irvin Langmuir and H. M. Mott-Smith published a theoretical model for the complex plasma sheath phenomenon in which they identified some very special cases which greatly simplified the sheath and allowed a closed solution to the problem. The most widely used application is for an electrostatic, or "Langmuir," probe in laboratory plasma. Although the Langmuir probe is physically simple (a biased wire) the theory describing its functional behavior and its current-voltage characteristic is extremely complex and, accordingly, a number of assumptions and approximations are used in the LMS model. These simplifications, correspondingly, place limits on the model's range of application. Adapting the LMS model to real-life conditions is the subject of numerous papers and dissertations. The Orbit-Motion Limited (OML) model that is widely used today is one of these adaptions that is a convenient means of calculating sheath effects. Since the Langmuir probe is a simple biased wire immersed in plasma, it is particularly tempting to use the OML equation in calculating the characteristics of the long, highly biased wires of an Electric Sail in the solar wind plasma. However, in order to arrive at the OML equation, a number of additional simplifying assumptions and approximations (beyond those made by Langmuir-Mott-Smith) are necessary. The OML equation is a good approximation when all conditions are met, but it would appear that the Electric Sail problem lies outside of the limits of applicability.

  15. Communicating LightSail: Embedded Reporting and Web Strategies for Citizen-Funded Space Missions

    NASA Astrophysics Data System (ADS)

    Hilverda, M.; Davis, J.

    2015-12-01

    The Planetary Society (TPS) is a non-profit space advocacy group with a stated mission to "empower the world's citizens to advance space science and exploration." In 2009, TPS began work on LightSail, a small, citizen-funded spacecraft to demonstrate solar sailing propulsion technology. The program included a test flight, completed in June 2015, with a primary mission slated for late 2016. TPS initiated a LightSail public engagement campaign to provide the public with transparent mission updates, and foster educational outreach. A credentialed science journalist was given unrestricted access to the team and data, and provided regular reports without editorial oversight. An accompanying website, sail.planetary.org, provided project updates, multimedia, and real-time spacecraft data during the mission. Design approaches included a clean layout with text optimized for easy reading, balanced by strong visual elements to enhance reader comprehension and interest. A dedicated "Mission Control" page featured social media feeds, links to most recent articles, and a ground track showing the spacecraft's position, including overflight predictions based on user location. A responsive, cross-platform design allowed easy access across a broad range of devices. Efficient web server performance was prioritized by implementing a static content management system (CMS). Despite two spacecraft contingencies, the test mission successfully completed its primary objective of solar sail deployment. Qualitative feedback on the transparent, embedded reporting style was positive, and website metrics showed high user retention times. The website also grew awareness and support for the primary 2016 mission, driving traffic to a Kickstarter campaign that raised $1.24 million. Websites constantly evolve, and changes for the primary mission will include a new CMS to better support multiple authors and a custom dashboard to display real-time spacecraft sensor data.

  16. Holographic Solar Photon Thrusters

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Matloff, Greg

    2006-01-01

    A document discusses a proposal to incorporate holographic optical elements into solar photon thrusters (SPTs). First suggested in 1990, SPTs would be systems of multiple reflective, emissive, and absorptive surfaces (solar sails) that would be attached to spacecraft orbiting the Earth to derive small propulsive forces from radiation pressures. An SPT according to the proposal would include, among other things, a main sail. One side of the sail would be highly emissive and would normally face away from the Earth. The other side would be reflective and would be covered by white-light holographic images that would alternately become reflective, transmissive, and absorptive with small changes in the viewing angle. When the spacecraft was at a favorable orbital position, the main sail would be oriented to reflect sunlight in a direction to maximize the solar thrust; when not in a favorable position, the main sail would be oriented to present a substantially absorptive/emissive aspect to minimize the solar drag. By turning the main sail slightly to alternate between the reflective and absorptive/ emissive extremes, one could achieve nearly a doubling or halving of the radiational momentum transfer and, hence, of the solar thrust.

  17. Design and development of a gossamer sail system for deorbiting in low earth orbit

    NASA Astrophysics Data System (ADS)

    Fernandez, Juan M.; Visagie, Lourens; Schenk, Mark; Stohlman, Olive R.; Aglietti, Guglielmo S.; Lappas, Vaios J.; Erb, Sven

    2014-10-01

    The accumulation of space debris in low Earth orbits poses an increasing threat of collisions and damage to spacecraft. As a low-cost solution to the space debris problem the Gossamer Deorbiter proposed herein is designed as a scalable stand-alone system that can be attached to a low-to-medium mass host satellite for end-of-life disposal from low Earth orbit. It consists of a 5 m by 5 m square solar/drag sail that uses four bistable carbon fiber booms for deployment and support. Prior to deployment of the gossamer structure, a telescopic enclosure system is used to displace the sail from the host craft in order to extend the sail without hindrance from the host peripherals, and also provide passive stabilization. The principal advantage of an entirely passive operational mode allows the drag augmentation system to act as a “fail-safe” device that would activate if the spacecraft suffers a catastrophic failure. Several scenarios are analyzed to study the potential application and performance of the system to current and future missions. A detailed breakdown of the mechanical subsystems of the Gossamer Deorbiter is presented, as well as the characterization process of the deployable booms and sail membrane and the full qualification testing campaign at component and system levels. Finally, the performance scalability of the concept is analyzed.

  18. Voyager Sails into Market for Reading

    ERIC Educational Resources Information Center

    Manzo, Kathleen Kennedy

    2006-01-01

    This article reports how the Voyager Universal Literacy core program, which is sailing successively into the market for reading programs, has been the target of several speculations over its secrets of success. Use of the Voyager Universal Literacy program has since spread to 1,000 districts throughout the country since its introduction into the…

  19. Combining Magnetic and Electric Sails for Interstellar Deceleration

    NASA Astrophysics Data System (ADS)

    Perakis, Nikolaos; Hein, Andreas M.

    2016-07-01

    The main benefit of an interstellar mission is to carry out in-situ measurements within a target star system. To allow for extended in-situ measurements, the spacecraft needs to be decelerated. One of the currently most promising technologies for deceleration is the magnetic sail which uses the deflection of interstellar matter via a magnetic field to decelerate the spacecraft. However, while the magnetic sail is very efficient at high velocities, its performance decreases with lower speeds. This leads to deceleration durations of several decades depending on the spacecraft mass. Within the context of Project Dragonfly, initiated by the Initiative of Interstellar Studies (i4is), this paper proposes a novel concept for decelerating a spacecraft on an interstellar mission by combining a magnetic sail with an electric sail. Combining the sails compensates for each technologys shortcomings: A magnetic sail is more effective at higher velocities than the electric sail and vice versa. It is demonstrated that using both sails sequentially outperforms using only the magnetic or electric sail for various mission scenarios and velocity ranges, at a constant total spacecraft mass. For example, for decelerating from 5% c, to interplanetary velocities, a spacecraft with both sails needs about 29 years, whereas the electric sail alone would take 35 years and the magnetic sail about 40 years with a total spacecraft mass of 8250 kg. Furthermore, it is assessed how the combined deceleration system affects the optimal overall mission architecture for different spacecraft masses and cruising speeds. Future work would investigate how operating both systems in parallel instead of sequentially would affect its performance. Moreover, uncertainties in the density of interstellar matter and sail properties need to be explored.

  20. [A paraplegic skipper of his own sailing yacht].

    PubMed

    Christians, U

    1985-05-01

    Drawing on personal experience, the author points out that paraplegics too are capable of independent sailing. Physical restrictions relative to on-board mobility, sail manoeuvring and change of sides can be made up for by structural adaptions and special techniques. Certain safety precautions are indispensable. The sailing performance of paraplegics compares with that of ablebodied sailors, and cruising under a paraplegic skipper's responsibility is certainly possible. PMID:4012026

  1. Validation of a Scalable Solar Sailcraft

    NASA Technical Reports Server (NTRS)

    Murphy, D. M.

    2006-01-01

    The NASA In-Space Propulsion (ISP) program sponsored intensive solar sail technology and systems design, development, and hardware demonstration activities over the past 3 years. Efforts to validate a scalable solar sail system by functional demonstration in relevant environments, together with test-analysis correlation activities on a scalable solar sail system have recently been successfully completed. A review of the program, with descriptions of the design, results of testing, and analytical model validations of component and assembly functional, strength, stiffness, shape, and dynamic behavior are discussed. The scaled performance of the validated system is projected to demonstrate the applicability to flight demonstration and important NASA road-map missions.

  2. A first course in optimum design of yacht sails

    NASA Astrophysics Data System (ADS)

    Sugimoto, Takeshi

    1993-03-01

    The optimum sail geometry is analytically obtained for the case of maximizing the thrust under equality and inequality constraints on the lift and the heeling moment. A single mainsail is assumed to be set close-hauled in uniform wind and upright on the flat sea surface. The governing parameters are the mast height and the gap between the sail foot and the sea surface. The lifting line theory is applied to analyze the aerodynamic forces acting on a sail. The design method consists of the variational principle and a feasibility study. Almost triangular sails are found to be optimum. Their advantages are discussed.

  3. Sail-assisted commercial marine vehicles: bibliography and abstracts

    SciTech Connect

    Shortall, J.W. III

    1983-01-01

    A bibliography that contains abstracts of 331 articles published on the subject of commercial sailing vessels and sail-assisted work boats of all kinds is presented. This is part of a continuing project supported both by the University of South Florida and the Florida Sea Grant College, and is an update of the previous publication of abstracts, Florida Sea Grant College Technical Paper No.24, May, 1982. Abstracts are compiled regularly, and subsequent reports will be issued periodically. A brief discussion of modern and historical commercial sail, the reasons for serious interest in same, and commercial sailing fishing vessels is presented.

  4. Experimental tests of beam-riding sail dynamics

    NASA Astrophysics Data System (ADS)

    Benford, James; Benford, Gregory; Gornostaeva, Olga; Garate, Eusebio; Anderson, Michael; Prichard, Alan; Harris, Henry

    2002-01-01

    Stability is a neglected issue in concepts for propelling ultralight sails by beamed power. Whether the beam comes from a laser or a microwave antenna, power falls with angle from the beam center. This drives a sail sideways under any lateral perturbation-``tumbling down the hill.'' The basic mechanics of pressures and sail averaging of them across its area remain unexplored in experiment, and have only recently been treated in theory. Here we report the first experiments on beam-riding dynamics in the laboratory, using a slightly over-weighted pendulum. In the experiments, a sail attached to the pendulum bottom is made unstable by adding weight to the top end. Sail stability and oscillation are possible if this is countered by electrodynamic beam pressure on the sail, directed from below, torquing the pendulum into a stable state. We present both data and analysis that shows that the beam-riding effect does in fact occur: microwave powers of a few hundred W can hold an otherwise unstable sail steady. This is made possible because of the gradient in beam power with sidewise angle. Our experiments verify the University of New Mexico simulations, which show similar stability conditions. Beam powers comparable to the strength of perturbing forces can plausibly achieve these stability effects in free sail flight. .

  5. Success and Interactive Learning: Sailing toward Student Achievement

    ERIC Educational Resources Information Center

    Midcap, Richard; Seitzer, Joan; Holliday, Randy; Childs, Amy; Bowser, Dana

    2008-01-01

    Success and Interactive Learning's (SAIL) front-loaded retention activities and unique financial incentives have combined to improve retention, persistence, and success of first-time college students. Its effectiveness has been validated through a comparison of retention rates and aggregate quality-point averages of SAIL cohorts with those rates…

  6. 33 CFR 161.19 - Sailing Plan (SP).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Sailing Plan (SP). 161.19 Section 161.19 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY VESSEL TRAFFIC MANAGEMENT Vessel Movement Reporting System § 161.19 Sailing...

  7. 33 CFR 161.19 - Sailing Plan (SP).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Sailing Plan (SP). 161.19 Section 161.19 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY VESSEL TRAFFIC MANAGEMENT Vessel Movement Reporting System § 161.19 Sailing...

  8. 33 CFR 161.19 - Sailing Plan (SP).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Sailing Plan (SP). 161.19 Section 161.19 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY VESSEL TRAFFIC MANAGEMENT Vessel Movement Reporting System § 161.19 Sailing...

  9. 33 CFR 161.19 - Sailing Plan (SP).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Sailing Plan (SP). 161.19 Section 161.19 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY VESSEL TRAFFIC MANAGEMENT Vessel Movement Reporting System § 161.19 Sailing...

  10. 33 CFR 161.19 - Sailing Plan (SP).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Sailing Plan (SP). 161.19 Section 161.19 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY VESSEL TRAFFIC MANAGEMENT Vessel Movement Reporting System § 161.19 Sailing...

  11. Large Space Telescopes Using Fresnel Lens for Power Beaming, Astronomy and Sail Missions

    SciTech Connect

    Early, J T

    2002-10-15

    The concept of using Fresnel optics as part of power beaming, astronomy or sail systems has been suggested by several authors. The primary issues for large Fresnel optics are the difficulties in fabricating these structures and deploying them in space and for astronomy missions the extremely narrow frequency range of these optics. In proposals where the telescope is used to transmit narrow frequency laser power, the narrow bandwidth has not been an issue. In applications where the optic is to be used as part of a telescope, only around 10{sup -5} to limited frequency response of a Fresnel optic is addressed by the use of a corrective optic that will broaden the frequency response of the telescope by three or four orders of magnitude. This broadening will dramatically increase the optical power capabilities of the system and will allow some spectroscopy studies over a limited range. Both the fabrication of Fresnel optics as large as five meters and the use of corrector optics for telescopes have been demonstrated at LLNL. For solar and laser sail missions the use of Fresnel amplitude zone plates made of very thin sail material is also discussed.

  12. 46 CFR 171.057 - Intact stability requirements for a sailing catamaran.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Intact stability requirements for a sailing catamaran... Intact stability requirements for a sailing catamaran. (a) A sailing vessel that operates on protected...) A sailing vessel that operates on partially protected or exposed waters must be designed to...

  13. 46 CFR 171.057 - Intact stability requirements for a sailing catamaran.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Intact stability requirements for a sailing catamaran... Intact stability requirements for a sailing catamaran. (a) A sailing vessel that operates on protected...) A sailing vessel that operates on partially protected or exposed waters must be designed to...

  14. 46 CFR 171.057 - Intact stability requirements for a sailing catamaran.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Intact stability requirements for a sailing catamaran... Intact stability requirements for a sailing catamaran. (a) A sailing vessel that operates on protected...) A sailing vessel that operates on partially protected or exposed waters must be designed to...

  15. 46 CFR 171.057 - Intact stability requirements for a sailing catamaran.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Intact stability requirements for a sailing catamaran... Intact stability requirements for a sailing catamaran. (a) A sailing vessel that operates on protected...) A sailing vessel that operates on partially protected or exposed waters must be designed to...

  16. Space Applications Industrial Laser System (SAILS)

    NASA Astrophysics Data System (ADS)

    McCay, T. D.; Bible, J. B.; Mueller, R. E.

    1993-10-01

    A program is underway to develop a YAG laser based materials processing workstation to fly in the cargo bay of the Space Shuttle. This workstation, called Space Applications Industrial Laser System (SAILS), will be capable of cutting and welding steel, aluminum, and Inconel alloys of the type planned for use in constructing the Space Station Freedom. As well as demonstrating the ability of a YAG laser to perform remote (fiber-optic delivered) repair and fabrication operations in space, fundamental data will be collected on these interactions for comparison with terrestrial data and models. The flight system, scheduled to fly in 1996, will be constructed as three modules using standard Get-Away-Special (GAS) canisters. The first module holds the laser head and cooling system, while the second contains a high peak power electrical supply. The third module houses the materials processing workstation and the command and data acquisition subsystems. The laser head and workstation cansisters are linked by a fiber-optic cable to transmit the laser light. The team assembled to carry out this project includes Lumonics Industrial Products (laser), Tennessee Technological University (structural analysis and fabrication), Auburn University Center for Space Power (electrical engineering), University of Waterloo (low-g laser process consulting), and CSTAR/UTSI (data acquisition, control, software, integration, experiment design). This report describes the SAILS program and highlights recent activities undertaken at CSTAR.

  17. The biology and medicine of sailing.

    PubMed

    Shephard, R J

    1990-02-01

    The physiological demands of sailing are highly specific, varying with wind conditions, type of craft, and crew position. In a light wind, the only physiological variable yet shown to influence performance is the resting blood sugar. Under high wind conditions, the skipper should be light (less than 60 kg), but crew members should be heavy (greater than 80 kg). Height does not seem a great advantage to crew, possibly because they then lack the muscular strength to exploit the added leverage. Muscle strength, endurance and a tolerance of anaerobic metabolism are all desirable attributes of crew, and competitive performance can be improved by a winter training programme that develops these aspects of muscle performance in the abdominal and thigh regions. The skipper must meet intense and prolonged cerebral demands in the face of periodic isometric work; performance may thus be helped by ingestion of carbohydrate over the course of a race. The ability to sustain isometric contractions in the 'hiking' position may also be improved if the muscles are preloaded with glycogen. The combination of a heavy body build, above average age for an athlete and sustained isometric contraction probably makes the yachting enthusiast vulnerable to ischaemic heart disease. Advisors to a sailing team must further take account of the risks presented by immersion in cold water, loss of sleep, circadian variations of performance over an event, and problems of motion sickness in rough weather. PMID:2180027

  18. Space Applications Industrial Laser System (SAILS)

    NASA Technical Reports Server (NTRS)

    Mccay, T. D.; Bible, J. B.; Mueller, R. E.

    1993-01-01

    A program is underway to develop a YAG laser based materials processing workstation to fly in the cargo bay of the Space Shuttle. This workstation, called Space Applications Industrial Laser System (SAILS), will be capable of cutting and welding steel, aluminum, and Inconel alloys of the type planned for use in constructing the Space Station Freedom. As well as demonstrating the ability of a YAG laser to perform remote (fiber-optic delivered) repair and fabrication operations in space, fundamental data will be collected on these interactions for comparison with terrestrial data and models. The flight system, scheduled to fly in 1996, will be constructed as three modules using standard Get-Away-Special (GAS) canisters. The first module holds the laser head and cooling system, while the second contains a high peak power electrical supply. The third module houses the materials processing workstation and the command and data acquisition subsystems. The laser head and workstation cansisters are linked by a fiber-optic cable to transmit the laser light. The team assembled to carry out this project includes Lumonics Industrial Products (laser), Tennessee Technological University (structural analysis and fabrication), Auburn University Center for Space Power (electrical engineering), University of Waterloo (low-g laser process consulting), and CSTAR/UTSI (data acquisition, control, software, integration, experiment design). This report describes the SAILS program and highlights recent activities undertaken at CSTAR.

  19. Exploring Unsteady Sail Propulsion in Olympic Class Sailboats

    NASA Astrophysics Data System (ADS)

    Schutt, Riley; Williamson, C. H. K.

    2014-11-01

    Unsteady sailing techniques, defined as ``flicking,'' ``roll-tacking'' and ``roll-gybing'' are used by athletes to propel their boats on an Olympic race course faster than using the wind alone. Body weight movements induce unsteady sail motion, increasing driving force and enhancing maneuvering performance. In this research, we explore the dynamics of an Olympic class Laser sailboat equipped with a GPS, IMU, wind sensor, and camera array. The velocity heading of a sailing boat is oriented at an apparent wind angle to the flow. In contrast to classic flapping propulsion, the heaving of the sail section (induced by the sailor's body movement) is not perpendicular to the sail's motion through the air. This leads to an ``exotic heave,'' with components parallel and perpendicular to the incident flow. The characteristic motion is recreated in a towing tank where the vortex structures generated by a representative 2-D sail section are observed, along with a measurement of thrust and lift forces. When combined with turning maneuvers, these heaving sail motions can lead to significant increases in velocity made good, a critical variable used when assessing racing performance.

  20. Optimal nodal flyby with near-Earth asteroids using electric sail

    NASA Astrophysics Data System (ADS)

    Mengali, Giovanni; Quarta, Alessandro A.

    2014-11-01

    The aim of this paper is to quantify the performance of an Electric Solar Wind Sail for accomplishing flyby missions toward one of the two orbital nodes of a near-Earth asteroid. Assuming a simplified, two-dimensional mission scenario, a preliminary mission analysis has been conducted involving the whole known population of those asteroids at the beginning of the 2013 year. The analysis of each mission scenario has been performed within an optimal framework, by calculating the minimum-time trajectory required to reach each orbital node of the target asteroid. A considerable amount of simulation data have been collected, using the spacecraft characteristic acceleration as a parameter to quantify the Electric Solar Wind Sail propulsive performance. The minimum time trajectory exhibits a different structure, which may or may not include a solar wind assist maneuver, depending both on the Sun-node distance and the value of the spacecraft characteristic acceleration. Simulations show that over 60% of near-Earth asteroids can be reached with a total mission time less than 100 days, whereas the entire population can be reached in less than 10 months with a spacecraft characteristic acceleration of 1 mm/s2.

  1. Non-linear phenomena in films of solar arrays

    NASA Technical Reports Server (NTRS)

    Zak, M.

    1979-01-01

    The paper assesses nonlinear effects in films which are associated with the instability of their shape as a result of contractions during longitudinal and transverse in-plane oscillations. The following problems are solved analytically: transverse in-plane oscillations, longitudinal oscillations in films of rotating solar sail, transverse in-plane oscillations in films of a rotating solar sail, and effect of damping in films of a rotating solar sail. The reason for damping lies in the loss of kinetic energy during absorption of the film particles by root wrinkles without reflection (absolutely inelastic shock).

  2. Re-Thinking the Use of the OML Model in Electric-Sail Development

    NASA Technical Reports Server (NTRS)

    Stone, Nobie H.

    2016-01-01

    The Orbit Motion Limited (OML) model commonly forms the basis for calculations made to determine the effect of the long, biased wires of an Electric Sail on solar wind protons and electrons (which determines the thrust generated and the required operating power). A new analysis of the results of previously conducted ground-based experimental studies of spacecraft-space plasma interactions indicate that the expected thrust created by deflected solar wind protons and the current of collected solar wind electrons could be considerably higher than the OML model would suggest. Herein the experimental analysis will be summarized and the assumptions and approximations required to derive the OML equation-and the limitations they impose-will be considered.

  3. Astronaut Terry Hart in orbiter training in the SAIL

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Astronaut Terry J. Hart, 41-C mission specialist, 'punches up' a display in an orbiter trainer in the JSC Shuttle Avionics Integration Laboratory (SAIL). The scenes Hart controls here appear in the 'windows' of the trainer.

  4. 26. STARBOARD PROFILE OF ALABAMA (ALABAMIAN) WITH SAILS SET Original ...

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

    26. STARBOARD PROFILE OF ALABAMA (ALABAMIAN) WITH SAILS SET Original 2-3/4'x2-1/4' photograph taken c. 1930? - Pilot Schooner "Alabama", Moored in harbor at Vineyard Haven, Vineyard Haven, Dukes County, MA

  5. View south of sail loft mid loft area. Note ...

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

    View south of sail loft - mid- loft area. Note inflatable boats undergoing pressure testing. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Structure Shop, League Island, Philadelphia, Philadelphia County, PA

  6. 56. AERIAL VIEW OF WIDE MEDIAN NEXT TO WASHINGTON SAILING ...

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

    56. AERIAL VIEW OF WIDE MEDIAN NEXT TO WASHINGTON SAILING MARINA LOOKING NORTH. - George Washington Memorial Parkway, Along Potomac River from McLean to Mount Vernon, VA, Mount Vernon, Fairfax County, VA

  7. STS-2: SAIL non-avionics subsystems math model requirements

    NASA Technical Reports Server (NTRS)

    Bennett, W. P.; Herold, R. W.

    1980-01-01

    Simulation of the STS-2 Shuttle nonavionics subsystems in the shuttle avionics integration laboratory (SAIL) is necessary for verification of the integrated shuttle avionics system. The math model (simulation) requirements for each of the nonavionics subsystems that interfaces with the Shuttle avionics system is documented and a single source document for controlling approved changes (by the SAIL change control panel) to the math models is provided.

  8. A Solar Sailcraft Simulation Application

    ERIC Educational Resources Information Center

    Celeda, Tomáš

    2013-01-01

    An application was created to encourage students' practical knowledge of gravitational fields, the law of conservation of energy and other phenomena, such as gravitational slingshots. The educational software simulates the flight of a solar sail spacecraft between two planets of the Solar System using the laws of gravity and radiation…

  9. Fundamentals of Plasma Sails Propulsion Concept

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Kabin, K.; Delamere, P. A.

    2002-01-01

    The Mini-Magnetospheric Plasma Propulsion (M2P2), originally proposed by Winglee et al. [2000], is based on the two-fluid plasma model and requires a 15-km frontal standoff distance (or 20-km cross-sectional diameter) in order for the magnetic bubble to absorb sufficient momentum from the SW to accelerate a spacecraft to the unprecedented speeds of 50-80 km/s after an acceleration period of about three months. Winglee et al. [2000] derived the above size requirement based on an extrapolation of their simulated results in which a system much smaller than a M2P2 was used (p. 21,074 of their study). We submit, however, that a fluid model has no validity for such a small scale size-even in the region near the plasma source! It is assumed in the MHD fluid model, normally applied to the magnetosphere, that the characteristic scale-size is much greater than the Larmor radius and ion skin depth of the SW. In the case of the M2P2, however, the size of the magnetic bubble is actually less than or, at best, comparable to, the scale of these characteristic parameters and, therefore, a kinetic approach, which addresses the smallscale physical mechanisms involved, must be used. A fully three-dimensional version of the hybrid code is used in our M2P2 (Plasma Sails) studies was originally developed by Delamere et al. [1999]. The M2P2 plasma sail is an excellent application for this hybrid code. The primary advantage of this code is the seamless interface between fluid and kinetic descriptions of the ion populations. A kinetic description is not necessary for the dense inner regions of the magnetic bubble and tremendous computational savings can be realized by treating this dense, magnetized ion population with the fluid description. It is essential, however, that the outer bubble regions be treated kinetically as well as the SW protons. Comparison of full size M2P2 simulation based on 3D MHD and kinetic models show that kinetic treatment introduces much more asymmetry to the

  10. Aerodynamic-structural model of offwind yacht sails

    NASA Astrophysics Data System (ADS)

    Mairs, Christopher M.

    An aerodynamic-structural model of offwind yacht sails was created that is useful in predicting sail forces. Two sails were examined experimentally and computationally at several wind angles to explore a variety of flow regimes. The accuracy of the numerical solutions was measured by comparing to experimental results. The two sails examined were a Code 0 and a reaching asymmetric spinnaker. During experiment, balance, wake, and sail shape data were recorded for both sails in various configurations. Two computational steps were used to evaluate the computational model. First, an aerodynamic flow model that includes viscosity effects was used to examine the experimental flying shapes that were recorded. Second, the aerodynamic model was combined with a nonlinear, structural, finite element analysis (FEA) model. The aerodynamic and structural models were used iteratively to predict final flying shapes of offwind sails, starting with the design shapes. The Code 0 has relatively low camber and is used at small angles of attack. It was examined experimentally and computationally at a single angle of attack in two trim configurations, a baseline and overtrimmed setting. Experimentally, the Code 0 was stable and maintained large flow attachment regions. The digitized flying shapes from experiment were examined in the aerodynamic model. Force area predictions matched experimental results well. When the aerodynamic-structural tool was employed, the predictive capability was slightly worse. The reaching asymmetric spinnaker has higher camber and operates at higher angles of attack than the Code 0. Experimentally and computationally, it was examined at two angles of attack. Like the Code 0, at each wind angle, baseline and overtrimmed settings were examined. Experimentally, sail oscillations and large flow detachment regions were encountered. The computational analysis began by examining the experimental flying shapes in the aerodynamic model. In the baseline setting, the

  11. 46 CFR 173.054 - Watertight subdivision and damage stability standards for new sailing school vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... for new sailing school vessels. 173.054 Section 173.054 Shipping COAST GUARD, DEPARTMENT OF HOMELAND....054 Watertight subdivision and damage stability standards for new sailing school vessels. (a) Each new sailing school vessel which has a mean length greater than 75 feet (22.8 meters) or which carries...

  12. 46 CFR 178.325 - Intact stability requirements for a sailing vessel.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Intact stability requirements for a sailing vessel. 178... Intact stability requirements for a sailing vessel. (a) Except as provided in paragraphs (b), (c) and (e) of this section, each sailing vessel must undergo a simplified stability proof test in...

  13. 46 CFR 178.325 - Intact stability requirements-monohull sailing vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Intact stability requirements-monohull sailing vessels....325 Intact stability requirements—monohull sailing vessels. (a) As permitted by § 178.310(c) of this part, a monohull sailing vessel may demonstrate compliance with paragraphs (b) or (c) of this...

  14. 46 CFR 169.218 - Procedures for designating sailing school vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Procedures for designating sailing school vessels. 169... SAILING SCHOOL VESSELS Inspection and Certification Letter of Designation § 169.218 Procedures for designating sailing school vessels. (a) Upon written request by a qualified institution, a determination...

  15. 46 CFR 173.054 - Watertight subdivision and damage stability standards for new sailing school vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... for new sailing school vessels. 173.054 Section 173.054 Shipping COAST GUARD, DEPARTMENT OF HOMELAND....054 Watertight subdivision and damage stability standards for new sailing school vessels. (a) Each new sailing school vessel which has a mean length greater than 75 feet (22.8 meters) or which carries...

  16. 46 CFR 169.218 - Procedures for designating sailing school vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Procedures for designating sailing school vessels. 169... SAILING SCHOOL VESSELS Inspection and Certification Letter of Designation § 169.218 Procedures for designating sailing school vessels. (a) Upon written request by a qualified institution, a determination...

  17. 46 CFR 173.055 - Watertight subdivision and damage stability standards for existing sailing school vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... for existing sailing school vessels. 173.055 Section 173.055 Shipping COAST GUARD, DEPARTMENT OF... § 173.055 Watertight subdivision and damage stability standards for existing sailing school vessels. (a) Except as provided in paragraph (c) of this section, an existing sailing school vessel which carries...

  18. 46 CFR 171.057 - Intact stability requirements for a sailing catamaran.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Intact stability requirements for a sailing catamaran... stability requirements for a sailing catamaran. (a) A sailing vessel that operates on protected waters must... vessel, in kilograms (pounds). X=4.88 kilograms/square meter (1.0 pounds/square foot). (b) A...

  19. 46 CFR 173.055 - Watertight subdivision and damage stability standards for existing sailing school vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... for existing sailing school vessels. 173.055 Section 173.055 Shipping COAST GUARD, DEPARTMENT OF... § 173.055 Watertight subdivision and damage stability standards for existing sailing school vessels. (a) Except as provided in paragraph (c) of this section, an existing sailing school vessel which carries...

  20. 46 CFR 178.325 - Intact stability requirements-monohull sailing vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Intact stability requirements-monohull sailing vessels....325 Intact stability requirements—monohull sailing vessels. (a) As permitted by § 178.310(c) of this part, a monohull sailing vessel may demonstrate compliance with paragraphs (b) or (c) of this...

  1. 46 CFR 173.054 - Watertight subdivision and damage stability standards for new sailing school vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... for new sailing school vessels. 173.054 Section 173.054 Shipping COAST GUARD, DEPARTMENT OF HOMELAND....054 Watertight subdivision and damage stability standards for new sailing school vessels. (a) Each new sailing school vessel which has a mean length greater than 75 feet (22.8 meters) or which carries...

  2. 46 CFR 173.055 - Watertight subdivision and damage stability standards for existing sailing school vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... for existing sailing school vessels. 173.055 Section 173.055 Shipping COAST GUARD, DEPARTMENT OF... § 173.055 Watertight subdivision and damage stability standards for existing sailing school vessels. (a) Except as provided in paragraph (c) of this section, an existing sailing school vessel which carries...

  3. 46 CFR 173.055 - Watertight subdivision and damage stability standards for existing sailing school vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... for existing sailing school vessels. 173.055 Section 173.055 Shipping COAST GUARD, DEPARTMENT OF... § 173.055 Watertight subdivision and damage stability standards for existing sailing school vessels. (a) Except as provided in paragraph (c) of this section, an existing sailing school vessel which carries...

  4. 46 CFR 169.218 - Procedures for designating sailing school vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Procedures for designating sailing school vessels. 169... SAILING SCHOOL VESSELS Inspection and Certification Letter of Designation § 169.218 Procedures for designating sailing school vessels. (a) Upon written request by a qualified institution, a determination...

  5. 46 CFR 173.054 - Watertight subdivision and damage stability standards for new sailing school vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... for new sailing school vessels. 173.054 Section 173.054 Shipping COAST GUARD, DEPARTMENT OF HOMELAND....054 Watertight subdivision and damage stability standards for new sailing school vessels. (a) Each new sailing school vessel which has a mean length greater than 75 feet (22.8 meters) or which carries...

  6. 46 CFR 169.218 - Procedures for designating sailing school vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Procedures for designating sailing school vessels. 169... SAILING SCHOOL VESSELS Inspection and Certification Letter of Designation § 169.218 Procedures for designating sailing school vessels. (a) Upon written request by a qualified institution, a determination...

  7. 46 CFR 169.218 - Procedures for designating sailing school vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Procedures for designating sailing school vessels. 169... SAILING SCHOOL VESSELS Inspection and Certification Letter of Designation § 169.218 Procedures for designating sailing school vessels. (a) Upon written request by a qualified institution, a determination...

  8. 46 CFR 178.325 - Intact stability requirements-monohull sailing vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Intact stability requirements-monohull sailing vessels....325 Intact stability requirements—monohull sailing vessels. (a) As permitted by § 178.310(c) of this part, a monohull sailing vessel may demonstrate compliance with paragraphs (b) or (c) of this...

  9. 46 CFR 173.054 - Watertight subdivision and damage stability standards for new sailing school vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... for new sailing school vessels. 173.054 Section 173.054 Shipping COAST GUARD, DEPARTMENT OF HOMELAND....054 Watertight subdivision and damage stability standards for new sailing school vessels. (a) Each new sailing school vessel which has a mean length greater than 75 feet (22.8 meters) or which carries...

  10. 46 CFR 173.055 - Watertight subdivision and damage stability standards for existing sailing school vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... for existing sailing school vessels. 173.055 Section 173.055 Shipping COAST GUARD, DEPARTMENT OF... § 173.055 Watertight subdivision and damage stability standards for existing sailing school vessels. (a) Except as provided in paragraph (c) of this section, an existing sailing school vessel which carries...

  11. 46 CFR 178.325 - Intact stability requirements-monohull sailing vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Intact stability requirements-monohull sailing vessels....325 Intact stability requirements—monohull sailing vessels. (a) As permitted by § 178.310(c) of this part, a monohull sailing vessel may demonstrate compliance with paragraphs (b) or (c) of this...

  12. System identification and the modeling of sailing yachts

    NASA Astrophysics Data System (ADS)

    Legursky, Katrina

    This research represents an exploration of sailing yacht dynamics with full-scale sailing motion data, physics-based models, and system identification techniques. The goal is to provide a method of obtaining and validating suitable physics-based dynamics models for use in control system design on autonomous sailing platforms, which have the capacity to serve as mobile, long range, high endurance autonomous ocean sensing platforms. The primary contributions of this study to the state-of-the-art are the formulation of a five degree-of-freedom (DOF) linear multi-input multi-output (MIMO) state space model of sailing yacht dynamics, the process for identification of this model from full-scale data, a description of the maneuvers performed during on-water tests, and an analysis method to validate estimated models. The techniques and results described herein can be directly applied to and tested on existing autonomous sailing platforms. A full-scale experiment on a 23ft monohull sailing yacht is developed to collect motion data for physics-based model identification. Measurements include 3 axes of accelerations, velocities, angular rates, and attitude angles in addition to apparent wind speed and direction. The sailing yacht herein is treated as a dynamic system with two control inputs, the rudder angle, deltaR, and the mainsail angle, delta B, which are also measured. Over 20 hours of full scale sailing motion data is collected, representing three sail configurations corresponding to a range of wind speeds: the Full Main and Genoa (abbrev. Genoa) for lower wind speeds, the Full Main and Jib (abbrev. Jib) for mid-range wind speeds, and the Reefed Main and Jib (abbrev. Reef) for the highest wind speeds. The data also covers true wind angles from upwind through a beam reach. A physics-based non-linear model to describe sailing yacht motion is outlined, including descriptions of methods to model the aerodynamics and hydrodynamics of a sailing yacht in surge, sway, roll, and

  13. Effects of DeOrbitSail as applied to Lifetime predictions of Low Earth Orbit Satellites

    NASA Astrophysics Data System (ADS)

    Afful, Andoh; Opperman, Ben; Steyn, Herman

    2016-07-01

    Orbit lifetime prediction is an important component of satellite mission design and post-launch space operations. Throughout its lifetime in space, a spacecraft is exposed to risk of collision with orbital debris or operational satellites. This risk is especially high within the Low Earth Orbit (LEO) region where the highest density of space debris is accumulated. This paper investigates orbital decay of some LEO micro-satellites and accelerating orbit decay by using a deorbitsail. The Semi-Analytical Liu Theory (SALT) and the Satellite Toolkit was employed to determine the mean elements and expressions for the time rates of change. Test cases of observed decayed satellites (Iridium-85 and Starshine-1) are used to evaluate the predicted theory. Results for the test cases indicated that the theory fitted observational data well within acceptable limits. Orbit decay progress of the SUNSAT micro-satellite was analysed using relevant orbital parameters derived from historic Two Line Element (TLE) sets and comparing with decay and lifetime prediction models. This paper also explored the deorbit date and time for a 1U CubeSat (ZACUBE-01). The use of solar sails as devices to speed up the deorbiting of LEO satellites is considered. In a drag sail mode, the deorbitsail technique significantly increases the effective cross-sectional area of a satellite, subsequently increasing atmospheric drag and accelerating orbit decay. The concept proposed in this study introduced a very useful technique of orbit decay as well as deorbiting of spacecraft.

  14. Comparative study of Suits and SAIL canopy reflectance models

    NASA Technical Reports Server (NTRS)

    Badhwar, G. D.; Verhoef, W.; Bunnik, N. J. J.

    1985-01-01

    A detailed understanding of the relationships between the canopy reflectance and the characteristics of canopy elements is an important factor for the full exploitation of the potential of remote sensing from aircraft and spacecraft altitudes to map vegetation and estimate key agronomic parameters such as the leaf area index (LAI) and biomass (BM). Suits (1972) idealized the canopy geometry by replacing each plant component with three orthogonal projections of that component. Verhoeff and Bunnik (1981) extended the Suits model, henceforth called the SAIL (Scattering from Arbitrarily Inclined Leaves) model, by removing certain constraints. The present investigation is concerned with an evaluation of the performance of the Suits and SAIL models, taking into account two data sets on soybean and corn. It was found that the tested models have significant deficiencies. However, the performance of the SAIL model is better than that of the Suits model because it provides a more realistic description of the canopy architecture.

  15. BOREAS TE-18 GeoSail Canopy Reflectance Model

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Huemmrich, K. Fred

    2000-01-01

    The SAIL (Scattering from Arbitrarily Inclined Leaves) model was combined with the Jasinski geo metric model to simulate canopy spectral reflectance and absorption of photosynthetically active radiation for discontinuous canopies. This model is called the GeoSail model. Tree shapes are described by cylinders or cones distributed over a plane. Spectral reflectance and transmittance of trees are calculated from the SAIL model to determine the reflectance of the three components used in the geometric model: illuminated canopy, illuminated background, shadowed canopy, and shadowed background. The model code is Fortran. sample input and output data are provided in ASCII text files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Activity Archive Center (DAAC).

  16. Kiteships, sailing vessels pulled and powered with a kite

    SciTech Connect

    Winter, F. de; Swenson, R.B.; Culp, D.

    1999-07-01

    Current windpower technology and future petroleum supply scenarios make it likely that it will become desirable to consider sailing vessels again for the merchant marine. For the wind-powered propulsion it seems possible to use tethered kites, instead of the traditional combination of masts and booms supporting a system of sails. This may be both safer and more cost-effective. The authors are on boat No. 2 in an R and D program aimed at this large scale application, and the present paper represents a progress report. Boat No. 1 was used to achieve speed and power, achieving a speed of 33 knots (over 60 km per hour), and sailing speeds at times of twice the wind velocity. Boat No. 2 will not be used for speed, but for the development of kite deployment and retrieval techniques, with kites of up to 300 sq ft (28 sq m) in surface area.

  17. Simulation of upwind maneuvering of a sailing yacht

    NASA Astrophysics Data System (ADS)

    Harris, Daniel Hartrick

    A time domain maneuvering simulation of an IACC class yacht suitable for the analysis of unsteady upwind sailing including tacking is presented. The simulation considers motions in six degrees of freedom. The hydrodynamic and aerodynamic loads are calculated primarily with unsteady potential theory supplemented by empirical viscous models. The hydrodynamic model includes the effects of incident waves. Control of the rudder is provided by a simple rate feedback autopilot which is augmented with open loop additions to mimic human steering. The hydrodynamic models are based on the superposition of force components. These components fall into two groups, those which the yacht will experience in calm water, and those due to incident waves. The calm water loads are further divided into zero Froude number, or "double body" maneuvering loads, hydrostatic loads, gravitational loads, free surface radiation loads, and viscous/residual loads. The maneuvering loads are calculated with an unsteady panel code which treats the instantaneous geometry of the yacht below the undisturbed free surface. The free surface radiation loads are calculated via convolution of impulse response functions derived from seakeeping strip theory. The viscous/residual loads are based upon empirical estimates. The aerodynamic model consists primarily of a database of steady state sail coefficients. These coefficients treat the individual contributions to the total sail force of a number of chordwise strips on both the main and jib. Dynamic effects are modeled by using the instantaneous incident wind velocity and direction as the independent variables for the sail load contribution of each strip. The sail coefficient database was calculated numerically with potential methods and simple empirical viscous corrections. Additional aerodynamic load calculations are made to determine the parasitic contributions of the rig and hull. Validation studies compare the steady sailing hydro and aerodynamic loads

  18. Hydrodynamics of sailing of the Portuguese man-of-war Physalia physalis

    PubMed Central

    Iosilevskii, G.; Weihs, D.

    2008-01-01

    Physalia physalis, commonly known as the Portuguese man-of-war (PMW), is a peculiar looking colony of specialized polyps. The most conspicuous members of this colony are the gas-filled sail-like float and the long tentacles, budding asymmetrically beneath the float. This study addresses the sailing of the PMW, and, in particular, the hydrodynamics of its trailing tentacles, the interaction between the tentacles and the float and the actual sailing performance. This paper attempts to provide answers for two of the many open questions concerning P. physalis: why does it need a sail? and how does it harness the sail? PMID:19091687

  19. Assessment of Inquiry Skills in the SAILS Project

    ERIC Educational Resources Information Center

    Harrison, Chris

    2014-01-01

    Inquiry provides both the impetus and experience that helps students acquire problem solving and lifelong learning skills. Teachers on the Strategies for Assessment of Inquiry Learning in Science Project (SAILS) strengthened their inquiry pedagogy, through focusing on seeking assessment evidence for formative action. This paper reports on both the…

  20. Learning the Ropes: A SpeyGrian Sailing Tale.

    ERIC Educational Resources Information Center

    McEwen, Christian

    2003-01-01

    Fourteen educators went Scottish island-hopping on a 100-year-old sailing boat to learn journal writing and new techniques in outdoor learning, gain confidence for teaching about controversial issues, and experience creative education in general. This narrative of their journey eloquently captures the essence and power of experiential, outdoor…

  1. Sail Training as Education: More than Mere Adventure

    ERIC Educational Resources Information Center

    McCulloch, K.; McLaughlin, P.; Allison, P.; Edwards, V.; Tett, L.

    2010-01-01

    This paper describes the process and findings of a multinational study of the characteristics of sail training for young people. The study used a structured qualitative method and involved "indigenous practitioner-researchers" who collected the majority of the data. Our findings show that participation provides an opportunity for learning in the…

  2. Starship Sails Propelled by Cost-Optimized Directed Energy

    NASA Astrophysics Data System (ADS)

    Benford, J.

    Microwave and laser-propelled sails are a new class of spacecraft using photon acceleration. It is the only method of interstellar flight that has no physics issues. Laboratory demonstrations of basic features of beam-driven propulsion, flight, stability (`beam-riding'), and induced spin, have been completed in the last decade, primarily in the microwave. It offers much lower cost probes after a substantial investment in the launcher. Engineering issues are being addressed by other applications: fusion (microwave, millimeter and laser sources) and astronomy (large aperture antennas). There are many candidate sail materials: carbon nanotubes and microtrusses, beryllium, graphene, etc. For acceleration of a sail, what is the cost-optimum high power system? Here the cost is used to constrain design parameters to estimate system power, aperture and elements of capital and operating cost. From general relations for cost-optimal transmitter aperture and power, system cost scales with kinetic energy and inversely with sail diameter and frequency. So optimal sails will be larger, lower in mass and driven by higher frequency beams. Estimated costs include economies of scale. We present several starship point concepts. Systems based on microwave, millimeter wave and laser technologies are of equal cost at today's costs. The frequency advantage of lasers is cancelled by the high cost of both the laser and the radiating optic. Cost of interstellar sailships is very high, driven by current costs for radiation source, antennas and especially electrical power. The high speeds necessary for fast interstellar missions make the operating cost exceed the capital cost. Such sailcraft will not be flown until the cost of electrical power in space is reduced orders of magnitude below current levels.

  3. Solar Kites for Earth magneto-tail monitoring

    NASA Astrophysics Data System (ADS)

    Lappas, Vaios; Wie, Bong; McInnes, Colin; Tarabini, Lorenzo; Gomes, Luis; Wallace, Kotska

    2006-08-01

    Solar Sails have been studied in the past as an alternative means of propulsion for spacecraft. Recent advances in Solar Sail technology and the miniaturisation of technology can drive these systems much smaller (<5 kg mass, <10m sail diameter) than existing sails, while still having a high delta-V and acceleration capability. With these unique capabilities of miniature Solar Sails, called Solar Kites, some very unique space science missions can be achieved which are difficult to be implemented using conventional propulsion techniques. One such unique candidate mission is to study the Earth's magnetotail. The paper lays out the main design features and technologies of a Solar Kite mission/platform and demonstrates that a cluster of Solar Kites with science payloads can provide multiple, in-situ measurments of the dynamic evolution of energetic particle distributions of the rotating geomagnetic tail of Earth. With a unique design, a Solar Kite proves to be an efficient, affordable and versatile solution for the mission analysed with a significant science return.

  4. Fluid-structure interaction analysis of deformation of sail of 30-foot yacht

    NASA Astrophysics Data System (ADS)

    Bak, Sera; Yoo, Jaehoon; Song, Chang Yong

    2013-06-01

    Most yacht sails are made of thin fabric, and they have a cambered shape to generate lift force; however, their shape can be easily deformed by wind pressure. Deformation of the sail shape changes the flow characteristics over the sail, which in turn further deforms the sail shape. Therefore, fluid-structure interaction (FSI) analysis is applied for the precise evaluation or optimization of the sail design. In this study, fluid flow analyses are performed for the main sail of a 30-foot yacht, and the results are applied to loading conditions for structural analyses. By applying the supporting forces from the rig, such as the mast and boom-end outhaul, as boundary conditions for structural analysis, the deformed sail shape is identified. Both the flow analyses and the structural analyses are iteratively carried out for the deformed sail shape. A comparison of the flow characteristics and surface pressures over the deformed sail shape with those over the initial shape shows that a considerable difference exists between the two and that FSI analysis is suitable for application to sail design.

  5. Assembly Of Space CFRP Structures With Racing Sailing Boats Technology

    NASA Astrophysics Data System (ADS)

    Nieto, Jose; Pipo, Alvaro; Santarsiero, Pablo; Yuste, Laura; Jaredson, Daniel

    2012-07-01

    Carbon Fiber Reinforced Plastic (CFRP) is commonly used in space applications due to the high payload costs derived from the launchers limitations. Most of larger parts of spatial structures are already made of CFRP but the achieved weight gain for that reason is seriously jeopardized because of the joints that usually consist of metallic brackets. This paper describes the work carried out to study and evaluate ways of reducing weight and cost of the joints between structural elements commonly used in space applications. The main objective of this project is to adapt design solutions coming from the racing sailing boats technology to space applications: the use of out-of autoclave cured CFRP joints. This study compares in terms of mechanical performances at theoretical level between traditional metallic solutions and innovative CFRP ones. Compatibility between a typical racing sailing boats material and space standards is also checked. Weight and cost of presented solutions are also compared.

  6. The physiological demands of sail pumping in Olympic level windsurfers.

    PubMed

    Vogiatzis, I; De Vito, G; Rodio, A; Madaffari, A; Marchetti, M

    2002-03-01

    This study investigated the physiological effects of sail pumping (PB)--a manoeuvre often adopted to provide additional propulsion to the board--in Olympic Class Windsurfing, following relaxation of the "no-pumping" rules by the International Federation. Fifteen Olympic-level windsurfers (10 men) from nine different countries volunteered for the study, which was performed during two international Olympic regattas. The measurements were carried out during actual sailing when both PB and not-pumping (NPB) using a portable metabolimeter. Windsurfing, when PB, elicited a dramatic increase in cardiorespiratory responses compared to NPB. Mean (SD) values for oxygen uptake and heart rate during NPB for the men and women were: 19.2 (4.4) and 15.7 (3.3) ml x kg(-1) x min(-1), and 110 (10) and 122 (12) beats x min(-1), respectively, whereas the values in PB were: 48.4 (5.7) and 40.2 (4.2) ml x kg(-1) x min(-1), and 165 (12) and 172 (13) beats x min(-1), respectively. All the PB parameters, with the exception of heart rate (HR), were significantly higher in the men than in the women but no differences were observed between the sexes in NPB with the exception of HR, which was higher in the women. Our results suggest sail pumping is as physically demanding as most aerobic sporting activities. In the context of the need to deal with a highly demanding athletic branch of sailing as part of an Olympic regatta, recommendations are made on how best to make physical and dietary preparations. PMID:11882932

  7. A multi-purpose SAIL demonstrator design and its principle experimental verification

    NASA Astrophysics Data System (ADS)

    Zhou, Yu; Yan, Aimin; Xu, Nan; Wang, Lijuan; Luan, Zhu; Sun, Jianfeng; Liu, Liren

    2009-08-01

    A fully 2-D synthetic aperture imaging ladar (SAIL) demonstrator is designed and being fabricated to experimentally investigate and theoretically analyze the beam diffraction properties, antenna function, imaging resolution and signal processing algorithm of SAIL. The design details of the multi-purpose SAIL demonstrator are given and, as the first phase, a laboratory-scaled SAIL system based on bulk optical elements has been built to verify the principle of design, which is similar in construction to the demonstrator but without the major antenna telescope. The system has the aperture diameter of about 1mm and the target distance of 3.2m.

  8. The sail wing windmill and its adaptation for use in rural India

    NASA Technical Reports Server (NTRS)

    Sherman, M. M.

    1973-01-01

    An 8 meter-diameter prototype sail wing windmill is reported that uses a one meter-diameter bullock cartwheel to which three bamboo poles are latched in a triangular pattern with overlapping ends, to form the airframe for cloth sails. This device lifts 300 pounds to a height of 20 feet in one minute in a 10 mph wind.

  9. 76 FR 36311 - Special Local Regulation; Extreme Sailing Series Boston; Boston Harbor, Boston, MA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-22

    ... Sailing Series Boston; Boston Harbor, Boston, Massachusetts, in the Federal Register (76 FR 20595). We... race area: All waters of Boston Harbor near Boston, MA, surface to bottom, encompassed by an area... participating in the Extreme Sailing Series event from entering the designated race area. DATES: This rule...

  10. 46 CFR 169.721 - Storm sails and halyards (exposed and partially protected waters only).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Storm sails and halyards (exposed and partially... § 169.721 Storm sails and halyards (exposed and partially protected waters only). (a) Unless clearly unsuitable, each vessel must have one storm trysail of appropriate size. It must be sheeted independently...

  11. 46 CFR 169.721 - Storm sails and halyards (exposed and partially protected waters only).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Storm sails and halyards (exposed and partially... § 169.721 Storm sails and halyards (exposed and partially protected waters only). (a) Unless clearly unsuitable, each vessel must have one storm trysail of appropriate size. It must be sheeted independently...

  12. 46 CFR 169.721 - Storm sails and halyards (exposed and partially protected waters only).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Storm sails and halyards (exposed and partially... § 169.721 Storm sails and halyards (exposed and partially protected waters only). (a) Unless clearly unsuitable, each vessel must have one storm trysail of appropriate size. It must be sheeted independently...

  13. 46 CFR 169.721 - Storm sails and halyards (exposed and partially protected waters only).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Storm sails and halyards (exposed and partially... § 169.721 Storm sails and halyards (exposed and partially protected waters only). (a) Unless clearly unsuitable, each vessel must have one storm trysail of appropriate size. It must be sheeted independently...

  14. 46 CFR 169.721 - Storm sails and halyards (exposed and partially protected waters only).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Storm sails and halyards (exposed and partially... § 169.721 Storm sails and halyards (exposed and partially protected waters only). (a) Unless clearly unsuitable, each vessel must have one storm trysail of appropriate size. It must be sheeted independently...

  15. Living at Sea: Learning from Communal Life Aboard Sail Training Vessels

    ERIC Educational Resources Information Center

    McCulloch, Ken

    2007-01-01

    This paper considers features of domestic and social life aboard sail training vessels, exploring the particular character of life at sea, and how these features contribute to the distinctive character of sail training experience as a context for learning. Methodologically, the study lies in the sociological tradition of ethnography, focusing on…

  16. 33 CFR 165.T11-0551 - Safety Zone; America's Cup Sailing Events.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... provisions of 33 CFR 165.23 apply to this safety zone. No person or vessel underway may enter or remain... Sailing Events. 165.T11-0551 Section 165.T11-0551 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 165.T11-0551 Safety Zone; America's Cup Sailing Events. (a) Definitions—(1) America's Cup...

  17. 46 CFR 178.320 - Intact stability requirements-non-sailing vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Intact stability requirements-non-sailing vessels. 178.320 Section 178.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER... Intact stability requirements—non-sailing vessels. (a) As permitted by § 178.310(c) of this part,...

  18. 46 CFR 178.320 - Intact stability requirements-non-sailing vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Intact stability requirements-non-sailing vessels. 178.320 Section 178.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER... Intact stability requirements—non-sailing vessels. (a) As permitted by § 178.310(c) of this part,...

  19. 46 CFR 178.320 - Intact stability requirements-non-sailing vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Intact stability requirements-non-sailing vessels. 178.320 Section 178.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER... Intact stability requirements—non-sailing vessels. (a) As permitted by § 178.310(c) of this part,...

  20. 46 CFR 178.320 - Intact stability requirements-non-sailing vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Intact stability requirements-non-sailing vessels. 178.320 Section 178.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER... Intact stability requirements—non-sailing vessels. (a) As permitted by § 178.310(c) of this part,...

  1. What Is Our Maritime Heritage? A Marine Education Infusion Unit on Ships and Sailing. Revised Edition.

    ERIC Educational Resources Information Center

    Butzow, John W.; And Others

    The heritage of ships and boats of northern New England serves as the focal point of this interdisciplinary unit for fifth- through ninth-grade students. Information on maritime heritage, buoyancy and flotation, building a whitehall rowing boat, masts and sails, basics of sailing, and northern New England ships and shipping is provided in the…

  2. Performance Evaluation of Leading Edge Slats on Rigid Wing Sail Catamarans

    NASA Astrophysics Data System (ADS)

    Johnson, Chelsea; O'Neill, Charles

    2015-11-01

    Rigid wing sails have created the fastest catamarans in history, however with the addition of a leading edge slat higher lift and faster speeds may be achieved. Slats are currently used on airplane wings to increase lift, but have not been implemented on a rigid wing sail catamaran. Using 3D modeling and computational fluid dynamics software, this research investigates the effect that slats have on the performance of rigid wing sail catamarans. Aerodynamics and hydrodynamics form the basis of the research. The preliminary results show an increase in the coefficient of lift for sail models with slats over sail models without slats, allowing the catamaran to perform at higher speeds. The ability of the slat to rotate has also been identified as a key factor in increasing the benefit of the slat. This work was supported by NSF site award 1358991.

  3. Power augmentation of cheap, sail-type, horizontal-axis wind-turbines

    NASA Astrophysics Data System (ADS)

    Fleming, P. D.; Probert, S. D.

    1982-09-01

    A history of the development of windpowered machinery is presented, and the installation of tipvanes and centerbodies to enhance the performance of low cost WECS for developing countries are examined experimentally. Particular attention is given to sail wing rotors equipped with tip fins, peristaltic pumps reparable by semiskilled labor, and various configurations of tip fins and center bodies, which deflect the wind outward from the hub to the sails. Cheap, flat-plate tip fins were found to effective in augmenting rotor performance by as much as 1.6 when facing only downwind. Best results were obtained with one tip vane per sail, with the fins downwind a distance at least equal to the pitch of a wind-filled sail. Further experimentation with stationary deflectors which redirect wind into the buckets of a Savonius rotor or the sails of a horizontal axis WECS are suggested.

  4. Use of a Virtual-Technological Sailing Program to Prepare Children With Disabilities for a Real Sailing Course: Effects on Balance and Quality of Life.

    PubMed

    Aprile, Irene; Iacovelli, Chiara; Iuvone, Laura; Imbimbo, Isabella; Cruciani, Arianna; Pecchioli, Cristiano; Manozzi, Francesco Maria; Padua, Luca

    2016-07-01

    Sailing might produce a positive effect on a patient's general health and become an integrated part of rehabilitation. Our hypothesis was that a specific technological rehabilitation program might be used to prepare a group of disabled subjects for sailing. Seventeen patients (age range: 9-20) with impairments in motor coordination and balance and 15 healthy subjects participated in the study. The study was divided into the virtual-technological sailing phase, theory-practice phase, and sports phase. Proprioceptive platforms were used to evaluate balance, and the Child Health Questionnaire-PF50 was used to evaluate quality of life. Trunk displacement and the center of pressure velocity improved significantly after the virtual-technological sailing program. As regards quality of life, the physical and psychosocial score significantly improved at the end of the program. A technological rehabilitation training improved balance in disabled subjects and may be used to prepare them for a real sailing course. Sailing improves the quality of life of disabled subjects and could be used in the rehabilitation. PMID:27021144

  5. Sail Plan Configuration Optimization for a Modern Clipper Ship

    NASA Astrophysics Data System (ADS)

    Gerritsen, Margot; Doyle, Tyler; Iaccarino, Gianluca; Moin, Parviz

    2002-11-01

    We investigate the use of gradient-based and evolutionary algorithms for sail shape optimization. We present preliminary results for the optimization of sheeting angles for the rig of the future three-masted clipper yacht Maltese Falcon. This yacht will be equipped with square-rigged masts made up of yards of circular arc cross sections. This design is especially attractive for megayachts because it provides a large sail area while maintaining aerodynamic and structural efficiency. The rig remains almost rigid in a large range of wind conditions and therefore a simple geometrical model can be constructed without accounting for the true flying shape. The sheeting angle optimization studies are performed using both gradient-based cost function minimization and evolutionary algorithms. The fluid flow is modeled by the Reynolds-averaged Navier-Stokes equations with the Spallart-Allmaras turbulence model. Unstructured non-conforming grids are used to increase robustness and computational efficiency. The optimization process is automated by integrating the system components (geometry construction, grid generation, flow solver, force calculator, optimization). We compare the optimization results to those done previously by user-controlled parametric studies using simple cost functions and user intuition. We also investigate the effectiveness of various cost functions in the optimization (driving force maximization, ratio of driving force to heeling force maximization).

  6. Gulf of Mexico Monitoring Via The Remotely Controlled CMR SailBuoy

    NASA Astrophysics Data System (ADS)

    Wienders, N.; Hole, L. R.; Peddie, D.

    2013-12-01

    The CMR SailBuoy is an unmanned ocean vessel capable of traveling the oceans for extended periods of time. It navigates the oceans autonomously - transmitting data at regular intervals using the Iridium network for two way communication. The SailBuoy can be used for a wide variety of ocean applications from measuring ocean and atmospheric parameters to tracking oil spills or acting as a communication relay station for subsea instrumentation. As part of the Deep-C project(Deep Sea to Coast Connectivity in the Eastern Gulf of Mexico), a two month campaign was carried out from March to May 2013 with the purpose of collecting sea surface data (temperature, salinity and oxygen) during the spring bloom. The campaign was unique in that the SailBouy was remotely controlled from Norway after being deployed from the RV Apalachee. The SailBuoy was deployed approximately 11 nautical miles (nm) south of Cape San Blas. During its mission she sailed approximately 840nm on a cruise track across the Gulf coast, from the Florida Panhandle to Louisiana. The SailBuoy project is part of Deep-C's physical oceanography research which seeks to, among other things, understand how particles and dissolved substances (such as oil) travel from the deep sea to the Louisiana, Mississippi, Alabama and Florida shorelines. This involves cross-shelf transport and upwelling mechanisms, which the SailBuoy is capable of measuring. An other focus was the sampling of the Mississippi river plume, which has been shown to influence the distribution of particles, oil, dissolved substances in the water, at least at the surface level. Sea surface salinity measurement via satellite do not provide, at the moment, sufficient resolution and accuracy and instead, the SailBuoy seems to be a very convenient instrument to track river plumes. In this presentation we describe the collected data and include comparisons with high resolution ocean model outputs. We also present further plans for SailBuoy campaigns.

  7. Enhancements in Photon Pressure Measurements Using a Solar Simulator

    NASA Technical Reports Server (NTRS)

    Gray, P. A.; Edwards, D. L.; Carruth, M. R., Jr.; Munafo, Paul (Technical Monitor)

    2001-01-01

    Initial proof of concept photon momentum measurements were reported at the AIAA Conference in Reno Nevada, January 8-11, 2001. That presentation verified that photon pressure on a simulated solar sail material can be measured under high vacuum conditions using a full spectrum solar simulator and a vacuum compatible force measurement system. Modifications to this test system were implemented to enhance the accuracy of the photon pressure measurement. This paper describes the photon pressure measurement technique and modifications to increase the measurement accuracy using a candidate sail material, aluminized Mylar.

  8. Intelligent annunciator for solar water heater

    NASA Astrophysics Data System (ADS)

    Chen, Xiao

    2009-07-01

    The solar water heater has advantages of low cost, no pollution, safety, energy conservation and is very suitable for users in rural area. But many now used solar water heater has no alarm device resulting water and resource wasting because of forgetting to turn off the valve after water sailing upstream. To overcome this defect, an intelligent annunciator for solar water heater installed at the end of the return pipe is presented and designed in order to remind the user. Firstly, the advantages and disadvantages of automatic and manual sailing upstream are compared concluding that manual sailing upstream is more trustiness. Then an annunciator for solar water heater is studied and ameliorated. Its principle, parameters index and functions are introduced. The annunciator uses CD4069 chip as the core circuit with very little assistant circuit. It can provide sound and light alarm at the same time. This annunciator for solar water heater water is very simple in production, low cost, the use of safe and convenient. The annunciator is applicable to all solar power products, including various types of early installation of solar power water heaters and water tanks without changing their structures. It can meet family and industrial environmental applications.

  9. Solar breeze power package and saucer ship

    SciTech Connect

    Veazey, S. E.

    1985-11-12

    A solar breeze power package having versatile sail and windmast options useful both on land and sea and especially useful in the saucer ship type design. The Vertical Axis Wind Turbine (VAWT) of the several Darrieus designs in conjunction with roll-up or permanently mounted solar cells combine in a hybrid or are used separately to provide power to a battery bank or other storage device.

  10. Saksenaea erythrospora infection following a serious sailing accident.

    PubMed

    Relloso, Silvia; Romano, Vanesa; Landaburu, Maria Fernanda; Herrera, Fabian; Smayevsky, Jorgelina; Veciño, Cecilia; Mujica, Maria Teresa

    2014-02-01

    Saksenaea erythrospora is a species of the order Mucorales recently described and reported as a cause of human mucormycosis. We report a case of S. erythrospora in a man involved in a serious sailing accident causing deep skin and soft tissue contamination with soil and water. Direct microscopic examination of the clinical sample with Giemsa stains showed hyaline and non-septate hyphae belonging to the order Mucorales. Fungal identification was performed by culture of biopsy material on SDA, and identification of species by floating an agar block containing the fungus in a nutritionally deficient medium consisting of sterile distilled water supplemented with 0.05 % yeast extract; and by sequencing the ITS region of the rDNA. This is the first report to our knowledge of infection with S. erythrospora in Argentina, confirming the presence of this fungus in this country. PMID:24298050

  11. POSTMAN: Point of Sail Tacking for Maritime Autonomous Navigation

    NASA Technical Reports Server (NTRS)

    Huntsberger, Terrance L.; Reinhart, Felix

    2012-01-01

    Waves apply significant forces to small boats, in particular when such vessels are moving at a high speed in severe sea conditions. In addition, small high-speed boats run the risk of diving with the bow into the next wave crest during operations in the wavelengths and wave speeds that are typical for shallow water. In order to mitigate the issues of autonomous navigation in rough water, a hybrid controller called POSTMAN combines the concept of POS (point of sail) tack planning from the sailing domain with a standard PID (proportional-integral-derivative) controller that implements reliable target reaching for the motorized small boat control task. This is an embedded, adaptive software controller that uses look-ahead sensing in a closed loop method to perform path planning for safer navigation in rough waters. State-of-the-art controllers for small boats are based on complex models of the vessel's kinematics and dynamics. They enable the vessel to follow preplanned paths accurately and can theoretically control all of the small boat s six degrees of freedom. However, the problems of bow diving and other undesirable incidents are not addressed, and it is questionable if a six-DOF controller with basically a single actuator is possible at all. POSTMAN builds an adaptive capability into the controller based on sensed wave characteristics. This software will bring a muchneeded capability to unmanned small boats moving at high speeds. Previously, this class of boat was limited to wave heights of less than one meter in the sea states in which it could operate. POSTMAN is a major advance in autonomous safety for small maritime craft.

  12. 33 CFR 83.25 - Sailing vessels underway and vessels under oars (Rule 25).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... shall have ready at hand an electric torch or lighted lantern showing a white light which shall be... in this Rule for sailing vessels, but if she does not, she shall have ready at hand an electric...

  13. 33 CFR 83.25 - Sailing vessels underway and vessels under oars (Rule 25).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... shall have ready at hand an electric torch or lighted lantern showing a white light which shall be... in this Rule for sailing vessels, but if she does not, she shall have ready at hand an electric...

  14. 33 CFR 83.25 - Sailing vessels underway and vessels under oars (Rule 25).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... shall have ready at hand an electric torch or lighted lantern showing a white light which shall be... in this Rule for sailing vessels, but if she does not, she shall have ready at hand an electric...

  15. 33 CFR 83.25 - Sailing vessels underway and vessels under oars (Rule 25).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... shall have ready at hand an electric torch or lighted lantern showing a white light which shall be... in this Rule for sailing vessels, but if she does not, she shall have ready at hand an electric...

  16. 33 CFR 83.25 - Sailing vessels underway and vessels under oars (Rule 25).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... shall have ready at hand an electric torch or lighted lantern showing a white light which shall be... in this Rule for sailing vessels, but if she does not, she shall have ready at hand an electric...

  17. Quantifying external focus of attention in sailing by means of action sport cameras.

    PubMed

    Pluijms, Joost P; Cañal-Bruland, Rouwen; Hoozemans, Marco J M; Van Beek, Morris W; Böcker, Kaj; Savelsbergh, Geert J P

    2016-08-01

    The aim of the current study was twofold: (1) to validate the use of action sport cameras for quantifying focus of visual attention in sailing and (2) to apply this method to examine whether an external focus of attention is associated with better performance in upwind sailing. To test the validity of this novel quantification method, we first calculated the agreement between gaze location measures and head orientation measures in 13 sailors sailing upwind during training regattas using a head mounted eye tracker. The results confirmed that for measuring visual focus of attention in upwind sailing, the agreement for the two measures was high (intraclass correlation coefficient (ICC) = 0.97) and the 95% limits of agreement were acceptable (between -8.0% and 14.6%). In a next step, we quantified the focus of visual attention in sailing upwind as fast as possible by means of an action sport camera. We captured sailing performance, operationalised as boat speed in the direction of the wind, and environmental conditions using a GPS, compass and wind meter. Four trials, each lasting 1 min, were analysed for 15 sailors each, resulting in a total of 30 upwind speed trials on port tack and 30 upwind speed trials on starboard tack. The results revealed that in sailing - within constantly changing environments - the focus of attention is not a significant predictor for better upwind sailing performances. This implicates that neither external nor internal foci of attention was per se correlated with better performances. Rather, relatively large interindividual differences seem to indicate that different visual attention strategies can lead to similar performance outcomes. PMID:26651850

  18. A novel antibody–drug conjugate targeting SAIL for the treatment of hematologic malignancies

    PubMed Central

    Kim, S Y; Theunissen, J-W; Balibalos, J; Liao-Chan, S; Babcock, M C; Wong, T; Cairns, B; Gonzalez, D; van der Horst, E H; Perez, M; Levashova, Z; Chinn, L; D‘Alessio, J A; Flory, M; Bermudez, A; Jackson, D Y; Ha, E; Monteon, J; Bruhns, M F; Chen, G; Migone, T-S

    2015-01-01

    Although several new therapeutic approaches have improved outcomes in the treatment of hematologic malignancies, unmet need persists in acute myeloid leukemia (AML), multiple myeloma (MM) and non-Hodgkin's lymphoma. Here we describe the proteomic identification of a novel cancer target, SAIL (Surface Antigen In Leukemia), whose expression is observed in AML, MM, chronic lymphocytic leukemia (CLL), diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). While SAIL is widely expressed in CLL, AML, MM, DLBCL and FL patient samples, expression in cancer cell lines is mostly limited to cells of AML origin. We evaluated the antitumor activity of anti-SAIL monoclonal antibodies, 7-1C and 67-7A, conjugated to monomethyl auristatin F. Following internalization, anti-SAIL antibody–drug conjugates (ADCs) exhibited subnanomolar IC50 values against AML cell lines in vitro. In pharmacology studies employing AML cell line xenografts, anti-SAIL ADCs resulted in significant tumor growth inhibition. The restricted expression profile of this target in normal tissues, the high prevalence in different types of hematologic cancers and the observed preclinical activity support the clinical development of SAIL-targeted ADCs. PMID:26024286

  19. Aerodynamics of yacht sails: viscous flow features and surface pressure distributions

    NASA Astrophysics Data System (ADS)

    Viola, Ignazio Maria

    2014-11-01

    The present paper presents the first Detached Eddy Simulation (DES) on a yacht sails. Wind tunnel experiments on a 1:15th model-scale sailing yacht with an asymmetric spinnaker (fore sail) and a mainsails (aft sail) were modelled using several time and grid resolutions. Also the Reynolds-average Navier-Stokes (RANS) equations were solved for comparison with DES. The computed forces and surface pressure distributions were compared with those measured with both flexible and rigid sails in the wind tunnel and good agreement was found. For the first time it was possible to recognise the coherent and steady nature of the leading edge vortex that develops on the leeward side of the asymmetric spinnaker and which significantly contributes to the overall drive force. The leading edge vortex increases in diameter from the foot to the head of the sail, where it becomes the tip vortex and convects downstream in the direction of the far field velocity. The tip vortex from the head of the mainsail rolls around the one of the spinnaker. The spanwise twist of the spinnaker leads to a mid-span helicoidal vortex, which has never been reported by previous authors, with an horizontal axis and rotating in the same direction of the tip vortex.

  20. NewsMars: Express journey to Mars ASE 2003: Knocked out by meteorites Events: Sun-Earth Day ASE 2003: Fun Physics - popular as ever Appointments: Sykes to bring science to the people UK Science Education: The future's bright, the future's science ASE 2003: A grand finale for Catherine Teaching Resources: UK goes to the planets Cambridge Physics Update: Basement physics Conferences: Earth Science Teachers' Association Conference 2003 New Website: JESEI sets sail GIREP: Teacher education seminar Malaysia: Rewards for curriculum change Cambridge Physics Update: My boomerang will come back! Teaching Resources: Widening particiption through ideas and evidence with the University of Surrey Wales: First Ffiseg Events: Nuna: Solar car on tour Physics on Stage: Physics on Stage 3 embraces life Symposium: In what sense a nuclear 'debate'? Gifted and Talented: Able pupils experiencing challenging science Australia: ISS flies high Down Under

    NASA Astrophysics Data System (ADS)

    2003-03-01

    Mars: Express journey to Mars ASE 2003: Knocked out by meteorites Events: Sun-Earth Day ASE 2003: Fun Physics - popular as ever Appointments: Sykes to bring science to the people UK Science Education: The future's bright, the future's science ASE 2003: A grand finale for Catherine Teaching Resources: UK goes to the planets Cambridge Physics Update: Basement physics Conferences: Earth Science Teachers' Association Conference 2003 New Website: JESEI sets sail GIREP: Teacher education seminar Malaysia: Rewards for curriculum change Cambridge Physics Update: My boomerang will come back! Teaching Resources: Widening particiption through ideas and evidence with the University of Surrey Wales: First Ffiseg Events: Nuna: Solar car on tour Physics on Stage: Physics on Stage 3 embraces life Symposium: In what sense a nuclear 'debate'? Gifted and Talented: Able pupils experiencing challenging science Australia: ISS flies high Down Under

  1. Replicas of the Santa Maria, Nina, Pinta sail by OV-105 on KSC LC Pad 39B

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Replicas of Christopher Columbus' sailing ships Santa Maria, Nina, and Pinta sail by Endeavour, Orbiter Vehicle (OV) 105, on Kennedy Space Center (KSC) Launch Complex (LC) Pad 39B awaiting liftoff on its maiden voyage, STS-49. Taken from the water, the silhouettes of the three sailing ships appear in the foreground with OV-105 atop the mobile launcher platform barely visible in the distant background. View provided by KSC with alternate number KSC-92PC-976.

  2. Inversion of vegetation canopy reflectance models for estimating agronomic variables. III - Estimation using only canopy reflectance data as illustrated by the suits model. IV - Total inversion of the SAIL model. [Scattering by Arbitrarily Inclined Leaves

    NASA Technical Reports Server (NTRS)

    Goel, N. S.; Thompson, R. L.

    1984-01-01

    The possibility of estimating agronomic and spectral parameters for a vegetation canopy from the canopy reflectance (CR) data in the infrared region is investigated for a set of solar/view directions. It is shown that such an estimation is possible, in principle, for the Suits (1972) model for a homogeneous canopy. The technique is then applied to a more complex model, the SAIL (scattering by arbitrarily inclined leaves) model which explicitly includes the leaf angle distribution in the computation of the canopy reflectance. It is concluded that, given the expected accuracy of CR measurements and the accuracy of the SAIL model in representing CR in the infrared region, the agronomic parameters, leaf area index, and leaf angle distribution can be estimated fairly accurately using ancillary data on spectral parameters.

  3. In-Space Propulsion Technologies for Robotic Exploration of the Solar System

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Meyer, Rae Ann; Frame, Kyle

    2006-01-01

    Supporting NASA's Science Mission Directorate, the In-Space Propulsion Technology Program is developing the next generation of space propulsion technologies for robotic, deep-space exploration. Recent technological advancements and demonstrations of key, high-payoff propulsion technologies have been achieved and will be described. Technologies under development and test include aerocapture, solar electric propulsion, solar sail propulsion, and advanced chemical propulsion.

  4. Optimizing ships’ behaviour when sailing in following seas

    NASA Astrophysics Data System (ADS)

    Acomi, O. C.; Boştină, A.; Boştină, A. L.; Acomi, N.

    2015-11-01

    Ships are built for sailing and transporting cargo on seas and oceans in weather conditions that are not friendly all the time. Even if the weather forecast is transmitted to vessels, the way of acting is a matter of officers’ judgement, based on their knowledge and experience. The subject of this paper is to analyse the behaviour of a port container vessel in different weather conditions. The method consists in using a specially developed software which takes into account the main particulars, the actual stability and the dynamic characteristics of the individual ship in the real voyage conditions, in order to obtain the Dangerous Zone Diagram. In order to avoid surf-riding and broaching the master should reduce speed to less than the critical speed. The results of the study are presented in a diagram that allow us to analyse the situation and to determine the ways for avoiding dangerous conditions by changing the course or the speed. The study should be regarded as a supporting tool during the decision making process.

  5. The influence of a yacht's heeling stability on optimum sail design

    NASA Astrophysics Data System (ADS)

    Sneyd, A. D.; Sugimoto, T.

    1997-01-01

    This paper presents fundamental results concerning the optimum design of yacht sails and masts. The aerodynamics of a high aspect ratio sail in uniform flow is analysed using lifting line theory to maximise thrust for a given sail area. The novel feature of this work is that thrust is optimised subject to the constraint that the aerodynamic heeling moment generated by the sail is balanced by the righting moment due to hull buoyancy (and the weight of the keel). Initially, the heel angle is therefore unknown, and determined as part of the solution process. Under the assumption of small heel angle, the problem reduces to minimising a quadratic form in the Fourier coefficients for the circulation distribution along the mast, and a simple analytic solution can be derived. It is found that if the mast is too high, the upper section is unused, and as a consequence there is a theoretically ideal mast height for a yacht of given heeling stability. Under the constraints of given sail area and heeling equilibrium it is found that no advantage is to be gained by allowing reverse circulation near the top of the mast. Various implications for yacht performance are discussed.

  6. Replicas of the Santa Maria, Nina, Pinta sail by OV-105 on KSC LC Pad 39B

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Replicas of Christopher Columbus' sailing ships Santa Maria, Nina, and Pinta sail by Endeavour, Orbiter Vehicle (OV) 105, on Kennedy Space Center (KSC) Launch Complex (LC) Pad 39B awaiting liftoff on its maiden voyage, STS-49. This view is a closeup of the ships with KSC launch complex in the distant background. View provided by KSC with alternate number KSC-92PC-968.

  7. Progress in outdoor navigation by the SAIL developmental robot

    NASA Astrophysics Data System (ADS)

    Zhang, Nan; Weng, John J.; Huang, Xiao

    2002-02-01

    A sensory mapping method, called Staggered Hierarchical Mapping (SHM), and its developmental algorithm are described in this paper. SHM is a model motivated by human early visual pathways including processing performed by the retina, Lateral Geniculate Nucleus (LGN) and the primary visual cortex. The work reported here concerns not only the design of such a series of processors but also their autonomous development. The primary goal is to address a long standing open problem of visual information processing in that processing elements that are dedicated to receptive fields of different retinal positions and different scales (sizes) must be concurrently functioning, in robotic and other applications in unstructured environments. A new Incremental Principal Component Analysis (IPCA) method is used to automatically develop orientation sensitive and other needed filters. For a fast convergence, the lateral inhibition of sensory neurons is modelled by what is called residual images. A set of staggered receptive fields models the pattern of positioning of processing cells. From sequentially sensed video frames, the proposed developing algorithm develops a hierarchy of filters, whose outputs are uncorrelated within each layer, but with increasing scale of receptive fields from low to higher layers. To study the completeness of the representation generated by the SHM, we experimentally show that the response produced at any layer is sufficient to corresponding retinal image. As an application domain, we describe out preliminary experiments of autonomous navigation by the SAIL robot, and why a mapping like the SHM is needed in our next phase of work of vision guided autonomous navigation in outdoor environments.

  8. Physiological demands of different sailing techniques of the new Olympic windsurfing class.

    PubMed

    Castagna, Olivier; Brisswalter, Jeanick; Lacour, Jean-René; Vogiatzis, Ioannis

    2008-12-01

    The introduction of the new Olympic class windsurf-board has prompted sailors to develop a new technique of sail "pumping" (rhythmically pulling the sail so that it acts as a wing). Contrary to the old technique that mainly involved upper body activity, the new one requires both upper and lower body muscle activity. Accordingly, the aim of the present study was to compare the performance characteristics of the board (speed and pointing angle ability relative to the direction of the wind) as well as the sailors' physiological demands during sail pumping with the old and new pumping techniques. Nineteen male, highly-trained (V(O)(2max)): 65.1 +/- 5.9 ml min(-1) kg(-1)), international level windsurfers from six different countries underwent two testing sessions on-water in a balanced order. Compared to the old pumping technique the mean distance sailed with the new technique (1,872 +/- 15 and 1,764 +/- 13 m, respectively) and the board speed (3.42 +/- 0.49 and 3.81 +/- 0.28 m s(-1), respectively) were significantly (P < 0.05) shorter and greater, respectively. Consequently, the time taken to sail the testing course was significantly shorter with the new compared to the old technique (390 +/- 8 vs. 420 +/- 16 s). Despite the finding that the new technique was sustained at a significantly higher fraction of V(O)(2max) (80.5 +/- 5.2 and 72.7 +/- 4.5%, respectively) compared to the old technique, total energy expenditure (130.7 +/- 11.3 and 128.1 +/- 9.2 Kcal, respectively) and blood lactate concentration 3 min into recovery (9.4 +/- 2.2 and 8.5 +/- 1.7 mmol l(-1), respectively) were not different. It is concluded that application of the new sail pumping technique improves the performance characteristics of the board without increasing the sailors' total metabolic requirement. PMID:18777039

  9. Economic feasibility of sail power devices on Great Lakes bulk carriers

    SciTech Connect

    1982-09-22

    Three ships were examined, the ED RYERSON, the ST. CLAIR, and the STEWART CORT to determine if retro-fitting these ships with a 3000 sq ft soft sail cat rig is economically feasible. By using existing weather data taken from recorded observations on Lake Michigan and Lake Superior and known performance characteristics of both the sailplan and hull, a computer program was written to model the problem. Three cases for each ship were estimated. The first was the average fuel savings, second was an optimistic estimate of fuel savings, and the third was a pessimistic estimate of fuel savings. Several considerations had to be taken into account that had serious consequences for the economic viability of the idea. One was the fact that all of the aforementioned ships have self unloading equipment that require about 80% of the deck space to be clear. This limited the choice of sailplans to one per ship. Another consideration is that due to bridge clearance problems an air draft of less than 125' was required. These two factors limited the size and efficiency of the sail plan. The third consideration is that due to the very tight shipping channels on the Great Lakes, there is no provision for altering course to take advantage of prevailing winds in order to maximize the usefulness of the sail device. The sail device on the ED RYERSON does not seem to be economically feasible. Even at the lowest interest rate investigated in this study (8%) the average annual cost improves only in the optimistic estimates. At 12% interest even this slight advantage disappears. The sail devices on the STEWART CORT and ST. CLAIR seem to be marginally feasible at low interest rates and the present cost of fuel. The STEWART CORT seems to benefit most from the fitting of a sail device. A modest increase in fuel prices, perhaps possible, will make both of these ships look substantially better.

  10. High energy gain in three-dimensional simulations of light sail acceleration

    SciTech Connect

    Sgattoni, A.; Sinigardi, S.; Macchi, A.

    2014-08-25

    The dynamics of radiation pressure acceleration in the relativistic light sail regime are analysed by means of large scale, three-dimensional (3D) particle-in-cell simulations. Differently to other mechanisms, the 3D dynamics leads to faster and higher energy gain than in 1D or 2D geometry. This effect is caused by the local decrease of the target density due to transverse expansion leading to a “lighter sail.” However, the rarefaction of the target leads to an earlier transition to transparency limiting the energy gain. A transverse instability leads to a structured and inhomogeneous ion distribution.

  11. Becoming a Coach in Developmental Adaptive Sailing: A Lifelong Learning Perspective

    PubMed Central

    Duarte, Tiago; Culver, Diane M.

    2014-01-01

    Life-story methodology and innovative methods were used to explore the process of becoming a developmental adaptive sailing coach. Jarvis's (2009) lifelong learning theory framed the thematic analysis. The findings revealed that the coach, Jenny, was exposed from a young age to collaborative environments. Social interactions with others such as mentors, colleagues, and athletes made major contributions to her coaching knowledge. As Jenny was exposed to a mixture of challenges and learning situations, she advanced from recreational para-swimming instructor to developmental adaptive sailing coach. The conclusions inform future research in disability sport coaching, coach education, and applied sport psychology. PMID:25210408

  12. Becoming a Coach in Developmental Adaptive Sailing: A Lifelong Learning Perspective.

    PubMed

    Duarte, Tiago; Culver, Diane M

    2014-10-01

    Life-story methodology and innovative methods were used to explore the process of becoming a developmental adaptive sailing coach. Jarvis's (2009) lifelong learning theory framed the thematic analysis. The findings revealed that the coach, Jenny, was exposed from a young age to collaborative environments. Social interactions with others such as mentors, colleagues, and athletes made major contributions to her coaching knowledge. As Jenny was exposed to a mixture of challenges and learning situations, she advanced from recreational para-swimming instructor to developmental adaptive sailing coach. The conclusions inform future research in disability sport coaching, coach education, and applied sport psychology. PMID:25210408

  13. Fission thrust sail as booster for high Δv fusion based propulsion

    NASA Astrophysics Data System (ADS)

    Ceyssens, Frederik; Wouters, Kristof; Driesen, Maarten

    2015-12-01

    The fission thrust sail as booster for nuclear fusion-based rocket propulsion for future starships is introduced and studied. First order calculations are used together with Monte Carlo simulations to assess system performance. If a D-D fusion rocket such as e.g. considered in Project Icarus has relatively low efficiency (~30%) in converting fusion fuel to a directed exhaust, adding a fission sail is shown to be beneficial for the obtainable delta-v. In addition, this type of fission-fusion hybrid propulsion has the potential to improve acceleration and act as a micrometeorite shield.

  14. Improved prediction of parachute line sail during lines-first deployment

    SciTech Connect

    Purvis, J.W.

    1984-04-01

    A numerical deployment simulation with the capability to predict line sail is presented. A finite element approach is used in which both canopy and suspension lines are modeled as flexible, distributed-mass structures connected to a finite-mass forebody. Translation and rotation of both the forebody and the deployment bag are determined from three-degree-of-freedom flight mechanics equations. The model includes all aspects of the deployment problem, such as suspension line aerodynamics, line ties, and canopy/deployment bag friction. The model has been verified by comparison with experimental data and used to investigate proposed solutions for a system with a line sail problem.

  15. The solar photon thruster as a terrestrial pole sitter.

    PubMed

    Matloff, Gregory L

    2004-05-01

    Geosynchronous satellites are invisible at high latitudes. A pole-sitting spacecraft would have communication, climate-studies, and near-polar Earth observation applications. We present a pole-sitter based on the solar photon thruster (SPT), a two-sail variant of the solar sail using a large curved collector sail (always normal to the Sun) to direct sunlight against a much smaller thruster. Thrust decreases slower for an SPT than for a conventional sail arrangement as the angle between sunlight and the collector normal increases. An SPT pole-sitter is offset from the terrestrial pole so that a component of Earth gravity balances the solar radiation-pressure component pushing the SPT off station. The component of gravitational attraction of the Earth pulling the spacecraft towards Earth is also balanced by a solar radiation-pressure component. Results are presented for 80-100% collector/thruster reflectivities. For a spacecraft areal mass thickness of 0.002 kg/m(2), collector and thruster reflectivities of 0.9, the SPT can be situated above latitude 45 degrees at a distance of approximately 60 Earth radii. An SPT pole sitter would be affected by lunar perturbation, which can be compensated for by an on-board rocket thruster producing 2 x 10(-6) g acceleration, a second SPT thruster sail thrusting against the influence of the Moon, or by directing a microwave beam against the spacecraft. Since an SPT pole sitter is in a position rather than an orbit, the effect of terrestrial gravitation limits the size and design of the payload package, which limits terrestrial target resolution. PMID:15220163

  16. Effects of a Tall Ship Sail Training Experience on Adolescents' Self-Concept

    ERIC Educational Resources Information Center

    Capurso, Michele; Borsci, Simone

    2013-01-01

    This study investigates the impact of a sail training education programme on the self-concept of a group of 147 adolescents. The Competence and Social domains of Bracken's self-concept scale were assessed by a quasi-experimental design in three phases: before commencement of the activities, on the last day of the voyage, and three months after…

  17. 76 FR 20595 - Special Local Regulation; Extreme Sailing Series Boston; Boston Harbor, Boston, MA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-13

    ..., 2008, issue of the Federal Register (73 FR 3316). Public Meeting We do not now plan to hold a public... prohibit vessels not participating in the Extreme Sailing Series event from entering the designated race... at high speeds on the race course, and large numbers of spectators on the adjacent Fan Pier in...

  18. Operation SAIL: One Effective Model for the Assimilation of New Students into a School District.

    ERIC Educational Resources Information Center

    Panagos, Jane L.; And Others

    1981-01-01

    Operation SAIL was designed to facilitate the assimilation of children who relocate from the inner city to suburban schools. The project includes faculty inservice training, parent orientation and involvement, and student cognitive and affective development. The methodology and results of the program's first year are described herein. (GC)

  19. Artificial equilibrium points for a generalized sail in the elliptic restricted three-body problem

    NASA Astrophysics Data System (ADS)

    Aliasi, Generoso; Mengali, Giovanni; Quarta, Alessandro A.

    2012-10-01

    Different types of propulsion systems with continuous and purely radial thrust, whose modulus depends on the distance from a massive body, may be conveniently described within a single mathematical model by means of the concept of generalized sail. This paper discusses the existence and stability of artificial equilibrium points maintained by a generalized sail within an elliptic restricted three-body problem. Similar to the classical case in the absence of thrust, a generalized sail guarantees the existence of equilibrium points belonging only to the orbital plane of the two primaries. The geometrical loci of existing artificial equilibrium points are shown to coincide with those obtained for the circular three body problem when a non-uniformly rotating and pulsating coordinate system is chosen to describe the spacecraft motion. However, the generalized sail has to provide a periodically variable acceleration to maintain a given artificial equilibrium point. A linear stability analysis of the artificial equilibrium points is provided by means of the Floquet theory.

  20. SAIL payload accommodations study. [ground handling for payload and avionics verification

    NASA Technical Reports Server (NTRS)

    Neubaur, R. J.

    1977-01-01

    Methods for accommodating payloads in SAIL are evaluated. It is concluded that a special payload be used as the standard method for verifying avionics systems and experiments. It is recommended that the baselined North door entrance method be retained for accommodation of flight type payloads.

  1. Deep Play. Rationality in the Life World with Special Reference to Sailing

    ERIC Educational Resources Information Center

    Goold, Patrick

    2014-01-01

    In an essay on the rationality of play, the author characterizes rationality by the three distinct demands it makes on the individual--demands for autonomy, solidarity, and integrity. He develops each of these as they apply to the sport of sailing, using the example of two deep-ocean expeditions to arrive at a concept of deep play he sees as one…

  2. 77 FR 4501 - Special Local Regulation and Safety Zone; America's Cup Sailing Events, San Francisco, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-30

    ...The Coast Guard proposes to adopt a temporary special local regulation and temporary safety zone for those portions of the ``America's Cup World Series,'' the ``Louis Vuitton Cup'' challenger selection series, and the ``America's Cup Finals Match'' sailing regattas that may be conducted in the waters of San Francisco Bay adjacent to the City of San Francisco waterfront in the vicinity of the......

  3. Submillimeter Astronomy Investigation of Line Specra (SAILS) - a balloon borne instrument

    NASA Technical Reports Server (NTRS)

    Seiffert, M. D.; Langer, W. D.; Lord, S. D.; Pearson, J.; McGrath, W. R.

    2000-01-01

    The Submillimeter Astronomy Investigation of Line Specra (SAILS) is a balloon-borne experiment under study for a 100 day ultra-long duration balloon mission. The experiment would survey the galactic plane with 1 arc minute angular resolution and 1 km/sec velocity resolution in the important submillimeter lines of CII, NII, and OI.

  4. Corrigendum: Sailing From the Seas of Chaos Into the Corridor of Stability.

    PubMed

    2016-03-01

    Lakens, D., & Evers, E. R. K. (2014). Sailing from the seas of chaos into the corridor of stability: Practical recommendations to increase the informational value of studies. Perspectives in Psychological Science, 9, 278-292. doi:10.1177/1745691614528520. PMID:26993282

  5. A Trip on the Oslofiord on the Training Sailing Vessel, Svanen.

    ERIC Educational Resources Information Center

    Larner, Tom

    1978-01-01

    Describing activities of secondary students who participate in a 5 1/2 day trip on the sailing training vessel, Svanen, this article illustrates outdoor education aboard a 96-foot, 3-masted schooner built in 1916 and currently used by the Oslo American School (a U.S. Dependent School) for field experiences. (JC)

  6. Propellantless AOCS Design for a 160-m, 450-kg Sailcraft of the Solar Polar Imager Mission

    NASA Technical Reports Server (NTRS)

    Wie, Bong; Thomas, Stephanie; Paluszek, Michael; Murphy, David

    2005-01-01

    An attitude and orbit control system (AOCS) is developed for a 160-m, 450-kg solar sail spacecraft of the Solar Polar Imager (SPI) mission. The SPI mission is one of several Sun- Earth Connections solar sail roadmap missions currently envisioned by NASA. A reference SPI sailcraft consists of a 160-m, 150-kg square solar sail, a 250-kg spacecraft bus, and 50-kg science payloads, The 160-m reference sailcraft has a nominal solar thrust force of 160 mN (at 1 AU), an uncertain center-of-mass/center-of-pressure offset of +/- 0.4 m, and a characteristic acceleration of 0.35 mm/sq s. The solar sail is to be deployed after being placed into an earth escaping orbit by a conventional launch vehicle such as a Delta 11. The SPI sailcraft first spirals inwards from 1 AU to a heliocentric circular orbit at 0.48 AU, followed by a cranking orbit phase to achieve a science mission orbit at a 75-deg inclination, over a total sailing time of 6.6 yr. The solar sail will be jettisoned after achieving the science mission orbit. This paper focuses on the solar sailing phase of the SPI mission, with emphasis on the design of a reference AOCS consisting of a propellantless primary ACS and a microthruster-based secondary (optional) ACS. The primary ACS employs trim control masses running along mast lanyards for pitch/yaw control together with roll stabilizer bars at the mast tips for quadrant tilt (roll) control. The robustness and effectiveness of such a propellantless primary ACS would be enhanced by the secondary ACS which employs tip-mounted, lightweight pulsed plasma thrusters (PPTs). The microPPT-based ACS is mainly intended for attitude recovery maneuvers from off-nominal conditions. A relatively fast, 70-deg pitch reorientation within 3 hrs every half orbit during the orbit cranking phase is shown to be feasible, with the primary ACS, for possible solar observations even during the 5-yr cranking orbit phase.

  7. Feasibility Study of Interstellar Missions Using Laser Sail Probes Ranging in Size from the Nano to the Macro

    NASA Technical Reports Server (NTRS)

    Malroy, Eric T.

    2010-01-01

    This paper presents the analysis examining the feasibility of interstellar travel using laser sail probes ranging in size from the nano to the macro. The relativistic differential equations of motion for a laser sail are set up and solved using the Pasic Method. The limitations of the analysis are presented and discussed. The requirements for the laser system are examined, including the thermal analysis of the laser sails. Black holes, plasma fields, atmospheric collisions and sun light are several methods discussed to enable the deceleration of the interstellar probe. A number of novel mission scenarios are presented including the embryonic transport of plant life as a precursor to the arrival of space colonies

  8. Replicas of the Santa Maria, Nina, Pinta sail by OV-105 on KSC LC Pad 39B

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Replicas of Christopher Columbus' sailing ships Santa Maria, Nina, and Pinta sail by Endeavour, Orbiter Vehicle (OV) 105, on Kennedy Space Center (KSC) Launch Complex (LC) Pad 39B awaiting liftoff on its maiden voyage, STS-49. This view, taken from behind the fixed service structure (FSS) tower and retracted rotating service structure (RSS), shows the three ships as they sail by in the distance. OV-105 and its orange external tank (ET) are only partially visible. View provided by KSC with alternate KSC number KSC-92PC-977.

  9. ASPEC: Solar power satellite

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The solar power satellite (SPS) will provide a clean, reliable source of energy for large-scale consumption. The system will use satellites in geostationary orbits around the Earth to capture the Sun's energy. The intercepted sunlight will be converted to laser beam energy that can be transmitted to the Earth's surface. Ground systems on the Earth will convert the transmissions from space into electric power. The preliminary design for the SPS consists of one satellite in orbit around the Earth transmitting energy to a single ground station. The SPS design uses multilayer solar cell technology arranged on a 20 km squared planar array to intercept sunlight and convert it to an electric voltage. Power conditioning devices then send the electricity to a laser, which transmits the power to the surface of the Earth. A ground station will convert the beam into electricity. Typically, a single SPS will supply 5 GW of power to the ground station. Due to the large mass of the SPS, about 41 million kg, construction in space is needed in order to keep the structural mass low. The orbit configuration for this design is to operate a single satellite in geosynchronous orbit (GEO). The GEO allows the system to be positioned above a single receiving station and remain in sunlight 99 percent of the time. Construction will take place in low Earth orbit (LEO); array sections, 20 in total, will be sailed on solar wind out to the GEO location in 150 days. These individual transportation sections are referred to as solar sailing array panels (SSAP's). The primary truss elements used to support the array are composed of composite tubular members in a pentahedral arrangement. Smart segments consisting of passive and active damping devices will increase the control of dynamic SPS modes.

  10. 33 CFR 83.09 - Narrow channels (Rule 9).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... NAVIGATION RULES RULES Steering and Sailing Rules Conduct of Vessels in Any Condition of Visibility § 83.09... necessary to permit safe passing. (b) Vessels of less than 20 meters in length; sailing vessels. A vessel of less than 20 meters in length or a sailing vessel shall not impede the passage of a vessel that...

  11. Simulation of synthetic aperture imaging ladar (SAIL) for three-dimensional target model

    NASA Astrophysics Data System (ADS)

    Yi, Ning; Wu, Zhen-Sen

    2010-11-01

    In conventional imaging laser radar, the resolution of target is constrained by the diffraction-limited, which includes the beamwidth of the laser in the target plane and the telescope's aperture. Synthetic aperture imaging Ladar (SAIL) is an imaging technique which employs aperture synthesis with coherent laser radar, the resolution is determined by the total frequency spread of the source and is independent of range, so can achieve fine resolution in long range. Ray tracing is utilized here to obtain two-dimensional scattering properties from three-dimensional geometric model of actual target, and range-doppler algorithm is used for synthetic aperture process in laser image simulation. The results show that the SAIL can support better resolution.

  12. 75 FR 41373 - Special Local Regulations for Marine Events; Port Huron to Mackinac Island Sail Race

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-16

    ...The Coast Guard will enforce a special local regulation for the annual Port Huron to Mackinac Island Sail Race. This action is necessary to safely control vessel movements in the vicinity of the race starting point and provide for the safety of the general boating public and commercial shipping. During this period, no person or vessel may enter the regulated area without the permission of the......

  13. Coupled attitude-orbit dynamics and control for displaced solar orbits

    NASA Astrophysics Data System (ADS)

    Gong, Shengping; Baoyin, Hexi; Li, Junfeng

    2009-09-01

    The paper discusses the coupled attitude-orbit dynamics of a solar sail. The equilibrium point of the coupled dynamical equations is obtained by designing the inertia of the sail. The stability of the equilibrium is analyzed through a linearization. It is found that the stability of the coupled equilibrium is determined by the stability of the attitude and orbital equilibrium point, respectively. For the sail discussed in this paper, the stability of the orbital equilibrium determines the stability of coupled system since the attitude is always marginally stable. Several numerical examples are employed to validate the conclusions. For unstable displaced orbits, active control is employed to stabilize the attitude and orbit. The results show that a small control torque can stabilize both the attitude and orbit.

  14. Speed control device for a heavy duty shaft. [solar sails for spacecraft propulsion

    NASA Technical Reports Server (NTRS)

    Ford, A. G. (Inventor)

    1980-01-01

    A speed control device is characterized by a reference speed shaft spatially related to a heavy duty shaft, a drive train for driving the reference speed shaft at a constant angular velocity, a drive train for driving the heavy duty shaft at a variable angular velocity and a speed control assembly for continuously comparing the angular velocity of the heavy duty shaft with the angular velocity of the reference speed shaft. A brake assembly is connected to the heavy duty shaft and is adapted to respond to errors in the angular velocity of the heavy duty shaft in order to reduce the angular velocity of the heavy duty shaft to that of the reference speed shaft.

  15. High-temperature adhesives for bonding polyimide film. [bonding Kapton film for solar sails

    NASA Technical Reports Server (NTRS)

    St.clair, A. K.; Slemp, W. S.; St.clair, T. L.

    1980-01-01

    Experimental polyimide resins were developed and evaluated as potential high temperature adhesives for bonding Kapton polyimide film. Lap shear strengths of Kapton/Kapton bonds were obtained as a function of test temperature, adherend thickness, and long term aging at 575 K (575 F) in vacuum. Glass transition temperatures of the polyimide/"Kapton" bondlines were monitored by thermomechanical analysis.

  16. Analysis and assessment of film materials and associated manufacturing processes for a solar sail

    NASA Technical Reports Server (NTRS)

    Bradbury, E. J.; Jakobsen, R. J.; Sliemers, F. A.

    1978-01-01

    Candidate resin manufacturers and film producers were surveyed to determine the availability of key materials and to establish the capabilities of fabricators to prepare ultrathin films of these materials within the capacity/cost/time constraints of the Halley program. Infrared spectra of three candidate samples were obtained by pressing each sample against an internal reflection crystal with the polymer sandwiched between the crystal and the metal backing. The sample size was such that less than one-fourth of the surface of the crystal was covered with the sample. This resulted in weak spectra requiring a six-fold expansion. Internal reflection spectra of the three samples were obtained using both a KRS-5 and a Ge internal reflection crystal. Subtracted infrared spectra of the three samples are presented.

  17. Cardiorespiratory and muscular responses to simulated upwind sailing exercise in Optimist sailors.

    PubMed

    Callewaert, Margot; Boone, Jan; Celie, Bert; De Clercq, Dirk; Bourgois, Jan G

    2014-02-01

    The aim of this work was to gain more insight into the cardiorespiratory and muscular (m. vastus lateralis) responses to simulated upwind sailing exercise in 10 high-level male and female Optimist sailors (10.8-14.4 years old). Hiking strap load (HSL) and cardiorespiratory variables were measured while exercising on a specially developed Optimist sailing ergometer. Electromyography (EMG) was used to determine mean power frequency (MPF) and root mean square (RMS). Near-infrared spectroscopy was used to measure deoxygenated Hemoglobin and Myoglobin concentration (deoxy[Hb+Mb]) and re-oxygenation. Results indicated that HSL and integrated EMG of the vastus lateralis muscle changed in accordance with the hiking intensity. Cardiorespiratory response demonstrated an initial significant increase and subsequently steady state in oxygen uptake (VO₂), ventilation (VE), and heart rate (HR) up to circa 40% VO₂peak, 30% VEpeak and 70% HRpeak respectively. At muscle level, results showed that highly trained Optimist sailors manage to stabilize the muscular demand and fatigue development during upwind sailing (after an initial increase). However, approaching the end of the hiking exercise, the MPF decrease, RMS increase, and deoxy[Hb+Mb] increase possibly indicate the onset of muscle fatigue. PMID:24018866

  18. Visual search, movement behaviour and boat control during the windward mark rounding in sailing.

    PubMed

    Pluijms, Joost P; Cañal-Bruland, Rouwen; Hoozemans, Marco J M; Savelsbergh, Geert J P

    2015-01-01

    In search of key-performance predictors in sailing, we examined to what degree visual search, movement behaviour and boat control contribute to skilled performance while rounding the windward mark. To this end, we analysed 62 windward mark roundings sailed without opponents and 40 windward mark roundings sailed with opponents while competing in small regattas. Across conditions, results revealed that better performances were related to gazing more to the tangent point during the actual rounding. More specifically, in the condition without opponents, skilled performance was associated with gazing more outside the dinghy during the actual rounding, while in the condition with opponents, superior performance was related to gazing less outside the dinghy. With respect to movement behaviour, superior performance was associated with the release of the trimming lines close to rounding the mark. In addition, better performances were related to approaching the mark with little heel, yet heeling the boat more to the windward side when being close to the mark. Potential implications for practice are suggested for each phase of the windward mark rounding. PMID:25105956

  19. Ecological dynamics of continuous and categorical decision-making: the regatta start in sailing.

    PubMed

    Araújo, Duarte; Davids, Keith; Diniz, Ana; Rocha, Luis; Santos, João Coelho; Dias, Gonçalo; Fernandes, Orlando

    2015-01-01

    Ecological dynamics of decision-making in the sport of sailing exemplifies emergent, conditionally coupled, co-adaptive behaviours. In this study, observation of the coupling dynamics of paired boats during competitive sailing showed that decision-making can be modelled as a self-sustained, co-adapting system of informationally coupled oscillators (boats). Bytracing the spatial-temporal displacements of the boats, time series analyses (autocorrelations, periodograms and running correlations) revealed that trajectories of match racing boats are coupled more than 88% of the time during a pre-start race, via continuous, competing co-adaptions between boats. Results showed that both the continuously selected trajectories of the sailors (12 years of age) and their categorical starting point locations were examples of emergent decisions. In this dynamical conception of decision-making behaviours, strategic positioning (categorical) and continuous displacement of a boat over the course in match-race sailing emerged as a function of interacting task, personal and environmental constraints. Results suggest how key interacting constraints could be manipulated in practice to enhance sailors' perceptual attunement to them in competition. PMID:24935665

  20. Solar-C Conceptual Spacecraft Design Study: Final Review. Release 2

    NASA Technical Reports Server (NTRS)

    Hopkins, Randall; Baysinger, Mike; Thomas, Dan; Heaton, Andy; Stough, Rob; Hill, Spencer; Owens, Jerry; Young, Roy; Fabisinski, Leo; Thomas, Scott; Kim, Tony; Cirtain, Jonathan

    2010-01-01

    This briefing package contains the conceptual spacecraft design completed by the Advanced Concepts Office (ED04) in support of the Solar-C Study. The mission is to succeed Hinode (Solar B), and is designed to study the polar regions of the sun. Included in the slide presentation are sections that review the payload data, and overall ground rules and assumptions, mission analysis and trajectory design, the conceptual spacecraft design section includes: (1) Integrated Systems Design, (2) Mass Properties (3) Cost, (4) Solar Sail Systems, (6) Propulsion, (7) Structures, (8) Thermal (9) Power (10) Avionics / GN&C. There are also conclusions and follow-up work that must be done. In the Back-up section there is information about the JAXA H-11A Launch Vehicle, scalability and spiral development, Mass Projections, a comparison of the TRL assessment for two potential vendors of solar sails, and a chart with the mass properties,

  1. Dietary supplementation and doping-related factors in high-level sailing

    PubMed Central

    2012-01-01

    Background Although dietary supplements (DSs) in sports are considered a natural need resulting from athletes’ increased physical demands, and although they are often consumed by athletes, data on DS usage in Olympic sailing are scarce. The aim of this study was to study the use of and attitudes towards DSs and doping problems in high-level competitive sailing. Methods The sample consisted of 44 high-level sailing athletes (5 of whom were female; total mean age 24.13 ± 6.67 years) and 34 coaches (1 of whom was female; total mean age 37.01 ± 11.70). An extensive, self-administered questionnaire of substance use was used, and the subjects were asked about sociodemographic data, sport-related factors, DS-related factors (i.e., usage of and knowledge about DSs, sources of information), and doping-related factors. The Kruskal-Wallis ANOVA was used to determine the differences in group characteristics, and Spearman’s rank order correlation and a logistic regression analysis were used to define the relationships between the studied variables. Results DS usage is relatively high. More than 77% of athletes consume DSs, and 38% do so on a regular basis (daily). The athletes place a high degree of trust in their coaches and/or physicians regarding DSs and doping. The most important reason for not consuming DSs is the opinion that DSs are useless and a lack of knowledge about DSs. The likelihood of doping is low, and one-third of the subjects believe that doping occurs in sailing (no significant differences between athletes and coaches). The logistic regression found crew number (i.e., single vs. double crew) to be the single significant predictor of DS usage, with a higher probability of DS consumption among single crews. Conclusion Because of the high consumption of DSs future investigations should focus on real nutritional needs in sailing sport. Also, since athletes reported that their coaches are the primary source of information about nutrition and DSs, further

  2. Sailing for Rehabilitation of Patients with Severe Mental Disorders: Results of a Cross Over Randomized Controlled Trial

    PubMed Central

    Carta, Mauro G; Maggiani, Federica; Pilutzu, Laura; Moro, Maria F; Mura, Gioia; Cadoni, Federica; Sancassiani, Federica; Vellante, Marcello; Machado, Sergio; Preti, Antonio

    2014-01-01

    This study set out to evaluate the effectiveness of a sailing and learning-to-sail rehabilitation protocol in a sample of patients diagnosed with severe mental disorders. The study was a randomized, crossover, waiting-list controlled trial, following recruitment in the Departments of Mental Health of South Sardinia. Participants were outpatients diagnosed with severe mental disorders, recruited through announcements to the directors of the Departments of Mental Health of South Sardinia. Out of the 40 patients enrolled in the study, those exposed to rehabilitation with sailing during a series of guided and supervised sea expeditions near the beach of Cagliari (Sardinia), where the aim to explore the marine environment while sailing was emphasized, showed a statistically significant improvement of their clinical status (measured by BPRS) and, as well, of their general functioning (measured by HoNOS Scale) against the control group. The improvement was maintained at follow-up for some months only: after 12 months, the patients returned to their baseline values on the measures of psychopathology and showed a worsening trend of their quality of life. Sailing can represent a substitute of important experiences that the patients with severe mental disorders miss because of their illness. PMID:25191520

  3. Sailing can improve quality of life of people with severe mental disorders: results of a cross over randomized controlled trial.

    PubMed

    Carta, Mauro Giovanni; Maggiani, Federica; Pilutzu, Laura; Moro, Maria Francesca; Mura, Gioia; Sancassiani, Federica; Vellante, Vellante; Migliaccio, Gian Mario; Machado, Sergio; Nardi, Antonio Egidio; Preti, Antonio

    2014-01-01

    The aim of this study was to evaluate the impact of a sailing rehabilitation program on the quality of life (QoL) in a sample of patients with severe mental disorders. The study adopted a randomized, crossover, waiting-list controlled design. The participants enrolled in the study were outpatients diagnosed with severe chronic mental disorders. The participants (N=40) exposed to rehabilitation with sailing took part in a series of supervised cruises near the gulf of Cagliari, South Sardinia, and showed a statistically significant improvement of their quality of life compared to the control group. This improvement was comparable to the improvement in psychopathologic status and social functioning as shown in a previous report of the same research project. The improvement was maintained at follow-up only during the trial and for a few months later: after 12 months, patients returned to their baseline values and their quality of life showed a worsening trend. This is the first study to show that rehabilitation with sailing may improve the quality of life of people with severe chronic mental disorders. In all likelihood, a program grounded on learning how to manage a sailing vessel - during which patients perform cruises that emphasize the exploration of the marine environment by sailing - might be interesting enough and capture the attention of the patients so as to favour greater effectiveness of standard rehabilitation protocols, but this should be specifically tested. PMID:25191521

  4. Sailing for rehabilitation of patients with severe mental disorders: results of a cross over randomized controlled trial.

    PubMed

    Carta, Mauro G; Maggiani, Federica; Pilutzu, Laura; Moro, Maria F; Mura, Gioia; Cadoni, Federica; Sancassiani, Federica; Vellante, Marcello; Machado, Sergio; Preti, Antonio

    2014-01-01

    This study set out to evaluate the effectiveness of a sailing and learning-to-sail rehabilitation protocol in a sample of patients diagnosed with severe mental disorders. The study was a randomized, crossover, waiting-list controlled trial, following recruitment in the Departments of Mental Health of South Sardinia. Participants were outpatients diagnosed with severe mental disorders, recruited through announcements to the directors of the Departments of Mental Health of South Sardinia. Out of the 40 patients enrolled in the study, those exposed to rehabilitation with sailing during a series of guided and supervised sea expeditions near the beach of Cagliari (Sardinia), where the aim to explore the marine environment while sailing was emphasized, showed a statistically significant improvement of their clinical status (measured by BPRS) and, as well, of their general functioning (measured by HoNOS Scale) against the control group. The improvement was maintained at follow-up for some months only: after 12 months, the patients returned to their baseline values on the measures of psychopathology and showed a worsening trend of their quality of life. Sailing can represent a substitute of important experiences that the patients with severe mental disorders miss because of their illness. PMID:25191520

  5. Sea Education Association's sailing research vessels as innovative platforms for long-term research and education

    NASA Astrophysics Data System (ADS)

    Joyce, P.; Carruthers, E. A.; Engels, M.; Goodwin, D.; Lavender Law, K. L.; Lea, C.; Schell, J.; Siuda, A.; Witting, J.; Zettler, E.

    2012-12-01

    Sea Education Association's (SEA) two research vessels, the SSV Corwith Cramer and the SSV Robert C. Seamans are unique in the research world. Not only do these ships perform advanced research using state of the art equipment, they do so under sail with high school, undergraduate, and graduate students serving as both the science team and the crew. Because of SEA's educational mission and reliance on prevailing winds for sailing, the vessels have been studying repeated tracks for decades, providing valuable long-term data sets while educating future marine scientists. The Corwith Cramer has been collecting data in the North Atlantic between New England, the Sargasso Sea, Bermuda, and the Caribbean since 1987 while the Robert C. Seamans has been operating in the Eastern Pacific between the US West Coast, Hawaii, and French Polynesia since 2001. The ships collect continuous electronic data from hull mounted ADCP, chirp, and a clean flowing seawater system logging temperature, salinity, in-vivo chlorophyll and CDOM fluorescence, and beam attenuation. The ships also periodically collect data from profiling CTDs with chlorophyll and CDOM fluorometers, transmissometers, and dissolved oxygen and PAR sensors. In addition to electronic data, archived long term data sets include physical samples from net tows such as marine plastic debris and tar, and plankton including Halobates (a marine insect), leptocephali (eel larvae), and phyllosoma (spiny lobster larvae). Both vessels are 134' brigantine rig tall ships and are designated sailing school vessels (SSV) by the US Coast Guard, and both have received instrumentation grants from NSF to provide high quality, reliable data that is submitted to the NSF R2R archives. Students sailing on these ships spend time on shore at the SEA campus in Woods Hole, MA taking classes in oceanography, nautical science, maritime studies and public policy. Each student is required to write a proposal for their research before heading to sea, and

  6. Plasmonic nanoparticle chain in a light field: a resonant optical sail.

    PubMed

    Albaladejo, Silvia; Sáenz, Juan José; Marqués, Manuel I

    2011-11-01

    Optical trapping and driving of small objects has become a topic of increasing interest in multidisciplinary sciences. We propose to use a chain made of metallic nanoparticles as a resonant light sail, attached by one end point to a transparent object and propelling it by the use of electromagnetic radiation. Driving forces exerted on the chain are theoretically studied as a function of radiation's wavelength and chain's alignments with respect to the direction of radiation. Interestingly, there is a window in the frequency spectrum in which null-torque equilibrium configuration, with minimum geometric cross section, corresponds to a maximum in the driving force. PMID:21942220

  7. Replicas of the Santa Maria, Nina, Pinta sail by OV-105 on KSC LC Pad 39B

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Replicas of Christopher Columbus' sailing ships Santa Maria, Nina, and Pinta sail by Endeavour, Orbiter Vehicle (OV) 105, on Kennedy Space Center (KSC) Launch Complex (LC) Pad 39B awaiting liftoff on its maiden voyage, STS-49. This view was taken from the water showing the three ships silhouetted in the foreground with OV-105 on mobile launcher platform profiled against fixed service structure (FSS) tower and rectracted rotating service structure (RSS) in the background. Next to the launch pad (at right) are the sound suppression water system tower and the liquid hydrogen (LH2) storage tank. View provided by KSC with alternate number KSC-92PC-970.

  8. Replicas of the Santa Maria, Nina, Pinta sail by OV-105 on KSC LC Pad 39B

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Replicas of Christopher Columbus' sailing ships Santa Maria, Nina, and Pinta sail by Endeavour, Orbiter Vehicle (OV) 105, on Kennedy Space Center (KSC) Launch Complex (LC) Pad 39B awaiting liftoff on its maiden voyage, STS-49. This view was taken from the water showing the three ships silhouetted in the foreground with OV-105 on mobile launcher platform profiled against fixed service structure (FSS) tower and rectracted rotating service structure (RSS) in the background. Next to the launch pad (at right) are the sound suppression water system tower and the liquid hydrogen (LH2) storage tank. View provided by KSC with alternate number KSC-92PC-971.

  9. Replicas of the Santa Maria, Nina, Pinta sail by OV-105 on KSC LC Pad 39B

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Replicas of Christopher Columbus' sailing ships Santa Maria, Nina, and Pinta sail by Endeavour, Orbiter Vehicle (OV) 105, on Kennedy Space Center (KSC) Launch Complex (LC) Pad 39B awaiting liftoff on its maiden voyage, STS-49. This view was taken from the water showing the three ships in the foreground with OV-105 on mobile launcher platform profiled against fixed service structure (FSS) tower and rectracted rotating service structure (RSS) in the background. Next to the launch pad (at right) are the sound suppression water system tower and the liquid hydrogen (LH2) storage tank. View provided by KSC with alternate number KSC-92PC-967.

  10. The 2009 NCTE Presidential Address: Sailing over the Edge--Navigating the Uncharted Waters of a World Gone Flat

    ERIC Educational Resources Information Center

    Beers, Kylene

    2010-01-01

    This article presents the text of the author's presidential address, delivered at the National Council of Teachers of English (NCTE) Annual Convention in Philadelphia, Pennsylvania, on November 22, 2009. For the author, the title of this president's address, "Sailing over the Edge: Navigating the Uncharted Waters of a World Gone Flat," calls to…

  11. The high speed buffer board: A SAIL EIA-485 communications accelerator card for the vector measuring current meter

    NASA Astrophysics Data System (ADS)

    Singer, Robin; Butler, Douglas M.

    1990-07-01

    A High Speed Buffer Board (HSBB) was developed for the Vector Measuring Current Meter (VMCM) to implement the transmission of data at 9600 baud over an EIA-485 link. The HSBB significantly extends the VMCM communication functionality, which was previously limited to 300 baud transmission via 20mA current loop or FSK telemetry. The increased speed allows rapid sampling of a large number of current meters on a common cable and the EIA-485 circuitry, which was designed for low power operation, provides a useful multipoint communication method for data transmission over long cable lengths. SAIL protocol (IEEE 997) was utilized to coordinate data transfer by the instruments on a common link. An MC68HC11 microcontroller resides in the VMCM, buffering data it receives at 300 baud from the VMCM UART. In response to a jumper selectable SAIL address, the MC68HC11 offloads the data 9600 baud via EIA-485 to the SAIL controller. Synchronous data collection from many instruments is ensured by the SAIL synoptic set command and an embedded resynchronization/reset command. The low power consumption allows deployments of six months or more with a standard VMCM battery stack.

  12. GONG Observations of Solar Surface Flows

    PubMed

    Hathaway; Gilman; Harvey; Hill; Howard; Jones; Kasher; Leibacher; Pintar; Simon

    1996-05-31

    Doppler velocity observations obtained by the Global Oscillation Network Group (GONG) instruments directly measure the nearly steady flows in the solar photosphere. The sun's differential rotation is accurately determined from single observations. The rotation profile with respect to latitude agrees well with previous measures, but it also shows a slight north-south asymmetry. Rotation profiles averaged over 27-day rotations of the sun reveal the torsional oscillation signal-weak, jetlike features, with amplitudes of 5 meters per second, that are associated with the sunspot latitude activity belts. A meridional circulation with a poleward flow of about 20 meters per second is also evident. Several characteristics of the surface flows suggest the presence of large convection cells. PMID:8662460

  13. Smooth Sailing.

    ERIC Educational Resources Information Center

    Price, Beverley; Pincott, Maxine; Rebman, Ashley; Northcutt, Jen; Barsanti, Amy; Silkunas, Betty; Brighton, Susan K.; Reitz, David; Winkler, Maureen

    1999-01-01

    Presents discipline tips from several teachers to keep classrooms running smoothly all year. Some of the suggestions include the following: a bear-cave warning system, peer mediation, a motivational mystery, problem students acting as the teacher's assistant, a positive-behavior-reward chain, a hallway scavenger hunt (to ensure quiet passage…

  14. Collimated proton acceleration in light sail regime with a tailored pinhole target

    SciTech Connect

    Wang, H. Y.; Zepf, M.; Yan, X. Q.

    2014-06-15

    A scheme for producing collimated protons from laser interactions with a diamond-like-carbon + pinhole target is proposed. The process is based on radiation pressure acceleration in the multi-species light-sail regime [B. Qiao et al., Phys. Rev. Lett. 105, 155002 (2010); T. P. Yu et al., Phys. Rev. Lett. 105, 065002 (2010)]. Particle-in-cell simulations demonstrate that transverse quasistatic electric field at TV/m level can be generated in the pinhole. The transverse electric field suppresses the transverse expansion of protons effectively, resulting in a higher density and more collimated proton beam compared with a single foil target. The dependence of the proton beam divergence on the parameters of the pinhole is also investigated.

  15. Lessons learned at sea--ocean sailing as a metaphor for surgical training.

    PubMed

    Fabri, Peter J

    2003-09-01

    Surgical education is in the process of tumultuous change. Mastering this change will require a new set of competencies and a new understanding of the medical education process. While accreditation agencies are rapidly working to define the new criteria and benchmarks, training programs are quickly pulling together curricula, objectives, and evaluation tools. Yet much has already been learned in other complex, high-risk activities. Blue water sailing, ocean racing, and trans-Atlantic crossing are all activities that require a renewed form of leadership and an understanding of how knowledge, skill, and behavior come together to define the competent sailor. Ideas learned in such endeavors may assist the surgical educator in defining the horizons and the hazards of this uncharted voyage. PMID:12946827

  16. Radiation-Pressure Acceleration of Ion Beams from Nanofoil Targets: The Leaky Light-Sail Regime

    SciTech Connect

    Qiao, B.; Zepf, M.; Borghesi, M.; Dromey, B.; Geissler, M.; Karmakar, A.; Gibbon, P.

    2010-10-08

    A new ion radiation-pressure acceleration regime, the 'leaky light sail', is proposed which uses sub-skin-depth nanometer foils irradiated by circularly polarized laser pulses. In the regime, the foil is partially transparent, continuously leaking electrons out along with the transmitted laser field. This feature can be exploited by a multispecies nanofoil configuration to stabilize the acceleration of the light ion component, supplementing the latter with an excess of electrons leaked from those associated with the heavy ions to avoid Coulomb explosion. It is shown by 2D particle-in-cell simulations that a monoenergetic proton beam with energy 18 MeV is produced by circularly polarized lasers at intensities of just 10{sup 19} W/cm{sup 2}. 100 MeV proton beams are obtained by increasing the intensities to 2x10{sup 20} W/cm{sup 2}.

  17. A Lunar-Based Spacecraft Propulsion Concept - The Ion Beam Sail

    NASA Technical Reports Server (NTRS)

    Brown, Ian G.; Lane, John E.; Youngquist, Robert C.

    2006-01-01

    We describe a concept for spacecraft propulsion by means of an energetic ion beam, with the ion source fixed at the spacecraft starting point (e.g., a lunar-based ion beam generator) and not onboard the vessel. This approach avoids the substantial mass penalty associated with the onboard ion source and power supply hardware, and vastly more energetic ion beam systems can be entertained. We estimate the ion beam parameters required for various scenarios, and consider some of the constraints limiting the concept. We find that the "ion beam sail' approach can be viable and attractive for journey distances not too great, for example within the Earth-Moon system, and could potentially provide support for journeys to the inner planets.

  18. Heliopause Explorer—a sailcraft mission to the outer boundaries of the solar system

    NASA Astrophysics Data System (ADS)

    Leipold, M.; Fichtner, H.; Heber, B.; Groepper, P.; Lascar, S.; Burger, F.; Eiden, M.; Niederstadt, T.; Sickinger, C.; Herbeck, L.; Dachwald, B.; Seboldt, W.

    2006-10-01

    Solar sail technology holds the promise of enhancing the interplanetary transportation infrastructure for low-cost space exploration missions in the new millennium, by exploiting the freely available, space-pervading resource of solar radiation pressure for primary propulsion. Despite the large distances to the Sun and the reduced solar radiation pressure, fast missions to the outer edge of our solar system belong to the promising mission applications of solar sails. In order to realize such a mission, the sailcraft would first perform a so-called "solar photonic assist", approaching the Sun to less than 0.3 AU thus exploiting the increased solar radiation pressure, to pick up enough orbital energy to enter a hyperbolic orbit. This concept has been extended to a double and triple solar approach which reduces the requirement for very high area-to-mass ratios of the sailcraft. The target distance of the Heliopause Explorer mission is set to 200 AU. The science objective was defined as to allow the Heliopause Explorer to perform in situ observations which cannot be obtained within the remaining life time of the two Voyager spacecraft. A first feasibility study was initiated to derive technology requirements for the realization of such a challenging deep space mission.

  19. Illumination from space with orbiting solar-reflector spacecraft

    NASA Technical Reports Server (NTRS)

    Canady, J. E., Jr.; Allen, J. L., Jr.

    1982-01-01

    The feasibility of using orbiting mirrors to reflect sunlight to Earth for several illumination applications is studied. A constellation of sixteen 1 km solar reflector spacecraft in geosynchronous orbit can illuminate a region 333 km in diameter to 8 lux, which is brighter than most existing expressway lighting systems. This constellation can serve one region all night long or can provide illumination during mornings and evenings to five regions across the United States. Preliminary cost estimates indicate such an endeavor is economically feasible. The studies also explain how two solar reflectors can illuminate the in-orbit nighttime operations of Space Shuttle. An unfurlable, 1 km diameter solar reflector spacecraft design concept was derived. This spacecraft can be packaged in the Space, Shuttle, transported to low Earth orbit, unfurled, and solar sailed to operational orbits up to geosynchronous. The necessary technical studies and improvements in technology are described, and potential environmental concerns are discussed.

  20. The SAIL Databank: building a national architecture for e-health research and evaluation

    PubMed Central

    Ford, David V; Jones, Kerina H; Verplancke, Jean-Philippe; Lyons, Ronan A; John, Gareth; Brown, Ginevra; Brooks, Caroline J; Thompson, Simon; Bodger, Owen; Couch, Tony; Leake, Ken

    2009-01-01

    Background Vast quantities of electronic data are collected about patients and service users as they pass through health service and other public sector organisations, and these data present enormous potential for research and policy evaluation. The Health Information Research Unit (HIRU) aims to realise the potential of electronically-held, person-based, routinely-collected data to conduct and support health-related studies. However, there are considerable challenges that must be addressed before such data can be used for these purposes, to ensure compliance with the legislation and guidelines generally known as Information Governance. Methods A set of objectives was identified to address the challenges and establish the Secure Anonymised Information Linkage (SAIL) system in accordance with Information Governance. These were to: 1) ensure data transportation is secure; 2) operate a reliable record matching technique to enable accurate record linkage across datasets; 3) anonymise and encrypt the data to prevent re-identification of individuals; 4) apply measures to address disclosure risk in data views created for researchers; 5) ensure data access is controlled and authorised; 6) establish methods for scrutinising proposals for data utilisation and approving output; and 7) gain external verification of compliance with Information Governance. Results The SAIL databank has been established and it operates on a DB2 platform (Data Warehouse Edition on AIX) running on an IBM 'P' series Supercomputer: Blue-C. The findings of an independent internal audit were favourable and concluded that the systems in place provide adequate assurance of compliance with Information Governance. This expanding databank already holds over 500 million anonymised and encrypted individual-level records from a range of sources relevant to health and well-being. This includes national datasets covering the whole of Wales (approximately 3 million population) and local provider-level datasets