The Experts below are selected from a list of 3480 Experts worldwide ranked by ideXlab platform

Wilkie W. Keats - One of the best experts on this subject based on the ideXlab platform.

  • Trajectory Design for a Solar-Sail Mission to Asteroid 2016 HO3
    'Springer Science and Business Media LLC', 2019
    Co-Authors: Heiligers M.j., Fernandez, Juan M., Stohlman, Olive R., Wilkie W. Keats
    Abstract:

    This paper proposes the use of solar-sail technology currently under development at NASA Langley Research Center for a CubeSat rendezvous mission with asteroid 2016 HO3, a quasi-satellite of Earth. Time-optimal trajectories are sought for within a 2022–2023 Launch Window, starting from an assumed Launcher ejection condition in the Earth-Moon system. The optimal control problem is solved through a particular implementation of a direct pseudo-spectral method for which initial guesses are generated through a relatively simple and straightforward genetic algorithm search on the optimal Launch date and sail attitude. The results show that the trajectories take 2.16–4.21 years to complete, depending on the assumed solar-sail reflectance model and solar-sail technology. To assess the performance of solar-sail propulsion for this mission, the trajectory is also designed assuming the use of solar electric propulsion. The resulting fuel-optimal trajectories take longer to complete than the solar-sail trajectories and require a propellant consumption that exceeds the expected propellant capacity onboard the CubeSat. This comparison demonstrates the superior performance of solar-sail technology for this mission.Astrodynamics & Space Mission

  • Trajectory Design for a Solar Sail Mission to Asteroid 2016 HO3
    2018
    Co-Authors: Heiligers M.j., Fernandez, Juan M., Stohlman, Olive R., Wilkie W. Keats
    Abstract:

    This paper proposes the use of solar-sail technology currently under development at NASA Langley Research Center for a CubeSat rendezvous mission with asteroid 2016 HO3, a quasi-satellite of Earth. Time-optimal trajectories are sought for within a 2022 – 2023 Launch Window, starting from an assumed Launcher ejection condition in the Earth-Moon system. The optimal control problem is solved through a particular implementation of a direct pseudo-spectral method for which initial guesses are generated through a relatively simple and straightforward genetic algorithm search on the optimal Launch date and sail attitude. The results show that the trajectories take 2.16 – 4.21 years to complete, depending on the assumed solar-sail reflectance model and solar-sail technology. To assess the performance of solar-sail propulsion for this mission, the trajectory is also designed assuming the use of near-term solar electric propulsion. The resulting fuel-optimal trajectories take longer to complete than the solar-sail trajectories and require a propellant consumption that exceeds the expected propellant capacity onboard the CubeSat. This comparison demonstrates the superior performance of solar-sail technology for this mission.Astrodynamics & Space Mission

  • Trajectory Design for a Solar Sail Mission to Asteroid 2016 HO3
    2018
    Co-Authors: Heiligers M.j., Fernandez, Juan M., Stohlman, Olive R., Wilkie W. Keats
    Abstract:

    This paper proposes the use of solar-sail technology currently under development at NASA Langley Research Center for a CubeSat rendezvous mission with asteroid 2016 HO3, a quasi-satellite of Earth. Time-optimal trajectories are sought for within a 2022 – 2023 Launch Window, starting from an assumed Launcher ejection condition in the Earth-Moon system. The optimal control problem is solved through a particular implementation of a direct pseudo-spectral method for which initial guesses are generated through a relatively simple and straightforward genetic algorithm search on the optimal Launch date and sail attitude. The results show that the trajectories take 2.16 – 4.21 years to complete, depending on the assumed solar-sail reflectance model and solar-sail technology. To assess the performance of solar-sail propulsion for this mission, the trajectory is also designed assuming the use of near-term solar electric propulsion. The resulting fuel-optimal trajectories take longer to complete than the solar-sail trajectories and require a propellant consumption that exceeds the expected propellant capacity onboard the CubeSat. This comparison demonstrates the superior performance of solar-sail technology for this mission

Mark Beckman - One of the best experts on this subject based on the ideXlab platform.

  • mission design for the lunar reconnaissance orbiter
    2007
    Co-Authors: Mark Beckman
    Abstract:

    The Lunar Reconnaissance Orbiter (LRO) will be the first mission under NASA's Vision for Space Exploration. LRO will fly in a low 50 km mean altitude lunar polar orbit. LRO will utilize a direct minimum energy lunar transfer and have a Launch Window of three days every two weeks. The Launch Window is defined by lunar orbit beta angle at times of extreme lighting conditions. This paper will define the LRO Launch Window and the science and engineering constraints that drive it. After lunar orbit insertion, LRO will be placed into a commissioning orbit for up to 60 days. This commissioning orbit will be a low altitude quasi-frozen orbit that minimizes stationkeeping costs during commissioning phase. LRO will use a repeating stationkeeping cycle with a pair of maneuvers every lunar sidereal period. The stationkeeping algorithm will bound LRO altitude, maintain ground station contact during maneuvers, and equally distribute periselene between northern and southern hemispheres. Orbit determination for LRO will be at the 50 m level with updated lunar gravity models. This paper will address the quasi-frozen orbit design, stationkeeping algorithms and low lunar orbit determination.

  • finding acceptable james webb space telescope mission orbits from a fixed ariane flight profile
    2005
    Co-Authors: Mark Beckman, Leigh Janes
    Abstract:

    The James Webb Space Telescope (JWST) will be Launched into orbit about the Sun/Earth L2 libration point. Trajectory design was recently completed which included expected separation states from the Ariane Launch vehicle, constraints such as eclipses, maximum orbit size, maximum Sun-Vehicle-Earth/Moon angles, and Launch opportunities. The results of this trajectory design give a set of possible trajectories for JWST with bounded stray light zones and provide a complete Launch Window. This data is also used to design the initial trajectory correction maneuver such that a maneuver towards the Sun is not required.

Heiligers M.j. - One of the best experts on this subject based on the ideXlab platform.

  • Trajectory Design for a Solar-Sail Mission to Asteroid 2016 HO3
    'Springer Science and Business Media LLC', 2019
    Co-Authors: Heiligers M.j., Fernandez, Juan M., Stohlman, Olive R., Wilkie W. Keats
    Abstract:

    This paper proposes the use of solar-sail technology currently under development at NASA Langley Research Center for a CubeSat rendezvous mission with asteroid 2016 HO3, a quasi-satellite of Earth. Time-optimal trajectories are sought for within a 2022–2023 Launch Window, starting from an assumed Launcher ejection condition in the Earth-Moon system. The optimal control problem is solved through a particular implementation of a direct pseudo-spectral method for which initial guesses are generated through a relatively simple and straightforward genetic algorithm search on the optimal Launch date and sail attitude. The results show that the trajectories take 2.16–4.21 years to complete, depending on the assumed solar-sail reflectance model and solar-sail technology. To assess the performance of solar-sail propulsion for this mission, the trajectory is also designed assuming the use of solar electric propulsion. The resulting fuel-optimal trajectories take longer to complete than the solar-sail trajectories and require a propellant consumption that exceeds the expected propellant capacity onboard the CubeSat. This comparison demonstrates the superior performance of solar-sail technology for this mission.Astrodynamics & Space Mission

  • Trajectory Design for a Solar Sail Mission to Asteroid 2016 HO3
    2018
    Co-Authors: Heiligers M.j., Fernandez, Juan M., Stohlman, Olive R., Wilkie W. Keats
    Abstract:

    This paper proposes the use of solar-sail technology currently under development at NASA Langley Research Center for a CubeSat rendezvous mission with asteroid 2016 HO3, a quasi-satellite of Earth. Time-optimal trajectories are sought for within a 2022 – 2023 Launch Window, starting from an assumed Launcher ejection condition in the Earth-Moon system. The optimal control problem is solved through a particular implementation of a direct pseudo-spectral method for which initial guesses are generated through a relatively simple and straightforward genetic algorithm search on the optimal Launch date and sail attitude. The results show that the trajectories take 2.16 – 4.21 years to complete, depending on the assumed solar-sail reflectance model and solar-sail technology. To assess the performance of solar-sail propulsion for this mission, the trajectory is also designed assuming the use of near-term solar electric propulsion. The resulting fuel-optimal trajectories take longer to complete than the solar-sail trajectories and require a propellant consumption that exceeds the expected propellant capacity onboard the CubeSat. This comparison demonstrates the superior performance of solar-sail technology for this mission.Astrodynamics & Space Mission

  • Trajectory Design for a Solar Sail Mission to Asteroid 2016 HO3
    2018
    Co-Authors: Heiligers M.j., Fernandez, Juan M., Stohlman, Olive R., Wilkie W. Keats
    Abstract:

    This paper proposes the use of solar-sail technology currently under development at NASA Langley Research Center for a CubeSat rendezvous mission with asteroid 2016 HO3, a quasi-satellite of Earth. Time-optimal trajectories are sought for within a 2022 – 2023 Launch Window, starting from an assumed Launcher ejection condition in the Earth-Moon system. The optimal control problem is solved through a particular implementation of a direct pseudo-spectral method for which initial guesses are generated through a relatively simple and straightforward genetic algorithm search on the optimal Launch date and sail attitude. The results show that the trajectories take 2.16 – 4.21 years to complete, depending on the assumed solar-sail reflectance model and solar-sail technology. To assess the performance of solar-sail propulsion for this mission, the trajectory is also designed assuming the use of near-term solar electric propulsion. The resulting fuel-optimal trajectories take longer to complete than the solar-sail trajectories and require a propellant consumption that exceeds the expected propellant capacity onboard the CubeSat. This comparison demonstrates the superior performance of solar-sail technology for this mission

Leigh Janes - One of the best experts on this subject based on the ideXlab platform.

  • finding acceptable james webb space telescope mission orbits from a fixed ariane flight profile
    2005
    Co-Authors: Mark Beckman, Leigh Janes
    Abstract:

    The James Webb Space Telescope (JWST) will be Launched into orbit about the Sun/Earth L2 libration point. Trajectory design was recently completed which included expected separation states from the Ariane Launch vehicle, constraints such as eclipses, maximum orbit size, maximum Sun-Vehicle-Earth/Moon angles, and Launch opportunities. The results of this trajectory design give a set of possible trajectories for JWST with bounded stray light zones and provide a complete Launch Window. This data is also used to design the initial trajectory correction maneuver such that a maneuver towards the Sun is not required.

Richon Karen - One of the best experts on this subject based on the ideXlab platform.

  • Libration Orbit Eclipse Avoidance Maneuver Study for the James Webb Space Telescope Mission
    2019
    Co-Authors: Yu Wayne, Richon Karen
    Abstract:

    Mission analysis of libration orbit trajectories at Sun-Earth/Moon L2 typically includes predictions of lunar and Earth eclipses during the mission life-time. The NASA James Webb Space Telescope (JWST) trajectory, by design, avoids these eclipses by pruning its Launch Window. In an off-nominal scenario where an eclipse is predicted, a maneuver strategy is needed. In this paper, trade studies are examined for JWST that characterize the burn magnitude, location, and epochs of multiple maneuver plans to avoid an eclipse. The results enable analysts to explore the space of feasible maneuver strategies during routine operations