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  • 1
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    Analysis of Cislunar Transfers from a Near Rectilinear Halo Orbit with High Power Solar Electric Propulsion (2018)
    In:  CASI
    Details
    Publication Date: 2019-07-20
    Description: As government and commercial interest in the exploration of the Moon and cislunar space has grown, Near Rectilinear Halo Orbits (NRHOs) have shown to be of particular interest as staging orbits for human exploration of the Moon. Once in such staging orbits, low thrust solar electric propulsion (SEP) can enable efficient transfer to other orbits in cislunar space. This paper captures ongoing analysis to design efficient transfers of a massive spacecraft from a L2 Southern NRHO to a Distant Retrograde Orbit, L1 Northern NRHO, and Flat L2 Halo Orbit using low thrust SEP. For each transfer type, reference transfer is designed for an assumed 39 t spacecraft with 26.6 kW SEP system. For each reference transfer, analysis is completed to understand the sensitivity of the transfer to changes in initial mass and SEP power and identify the optimal number of thrusters to use for a given combination of mass and power.
    Keywords: Astrodynamics
    Type: GRC-E-DAA-TN60183 , AIAA Astrodynamics Specialist Conference 2018; Aug 19, 2018 - Aug 23, 2018; Snowbird, UT; United States
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 2
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    Analysis of Near Rectilinear Halo Orbit Insertion with a 40-kW Solar Electric Propulsion System (2018)
    In:  CASI
    Details
    Publication Date: 2019-07-20
    Description: This paper examines low thrust trajectories for delivery of a 40-kW solar electric propulsion spacecraft and potential additional payload to a desired NRHO. One option considered is a trans-lunar injection launch as a co-manifested payload on the Space Launch System. For this option, a reference trajectory is designed and a scan of launch dates is completed to understand the propellant mass sensitivity. A 15-day period cyclical variation in required propellant is observed that is attributed to solar gravity effects. A second option considered is to launch on a smaller commercial launch vehicle to a less energetic elliptical orbit and use SEP to spiral out to NRHO. For this option, analysis is completed to understand the trades between delivered mass to NRHO, total propellant required, time of flight, and solar array degradation. Results show that, while launching to lower altitudes can deliver greater payload mass to NRHO, significant solar array degradation can be observed.
    Keywords: Astrodynamics
    Type: GRC-E-DAA-TN60185 , AAS/AIAA Astrodynamics Specialist Conference; Aug 19, 2018 - Aug 23, 2018; Snowbird, UT; United States
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 3
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    Parallel Monotonic Basin Hopping for Low Thrust Trajectory Optimization (2018)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Monotonic Basin Hopping has been shown to be an effective method of solving low thrust trajectory optimization problems. This paper outlines an extension to the common serial implementation by parallelizing it over any number of available compute cores. The Parallel Monotonic Basin Hopping algorithm described herein is shown to be an effective way to more quickly locate feasible solutions, and improve locally optimal solutions in an automated way without requiring a feasible initial guess. The increased speed achieved through parallelization enables the algorithm to be applied to more complex problems that would otherwise be impractical for a serial implementation. Low thrust cislunar transfers and a hybrid Mars example case demonstrate the effectiveness of the algorithm. Finally, a preliminary scaling study quantifies the expected decrease in solve time compared to a serial implementation.
    Keywords: Astrodynamics
    Type: GRC-E-DAA-TN51148 , AIAA SciTech Forum, AAS/AIAA Space Flight Mechanics Meeting; Jan 08, 2018 - Jan 12, 2018; Kissimmee, FL; United States
    Format: application/pdf
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  • 4
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    Low Thrust Cis-Lunar Transfers Using a 40 kW-Class Solar Electric Propulsion Spacecraft (2017)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: This paper captures trajectory analysis of a representative low thrust, high power Solar Electric Propulsion (SEP) vehicle to move a mass around cis-lunar space in the range of 20 to 40 kW power to the Electric Propulsion (EP) system. These cis-lunar transfers depart from a selected Near Rectilinear Halo Orbit (NRHO) and target other cis-lunar orbits. The NRHO cannot be characterized in the classical two-body dynamics more familiar in the human spaceflight community, and the use of low thrust orbit transfers provides unique analysis challenges. Among the target orbit destinations documented in this paper are transfers between a Southern and Northern NRHO, transfers between the NRHO and a Distant Retrograde Orbit (DRO) and a transfer between the NRHO and two different Earth Moon Lagrange Point 2 (EML2) Halo orbits. Because many different NRHOs and EML2 halo orbits exist, simplifying assumptions rely on previous analysis of orbits that meet current abort and communication requirements for human mission planning. Investigation is done into the sensitivities of these low thrust transfers to EP system power. Additionally, the impact of the Thrust to Weight ratio of these low thrust SEP systems and the ability to transit between these unique orbits are investigated.
    Keywords: Astrodynamics; Spacecraft Propulsion and Power
    Type: AAS 17-583 , GRC-E-DAA-TN45566 , AAS/AIAA Astrodynamics Specialist Conference 2017; Aug 20, 2017 - Aug 24, 2017; Stevenson, WA; United States
    Format: application/pdf
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  • 5
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    Analysis of Near Rectilinear Halo Orbit Insertion with a 40-kW Solar Electric Propulsion System (2018)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: This paper examines low thrust trajectories for delivery of a 40-kW solar electric propulsion spacecraft and potential additional payload to a desired NRHO. One option considered is a trans-lunar injection launch as a co-manifested payload on the Space Launch System. For this option, a reference trajectory is designed and a scan of launch dates is completed to understand the propellant mass sensitivity. A 15-day period cyclical variation in required propellant is observed that is attributed to solar gravity effects. A second option considered is to launch on a smaller commercial launch vehicle to a less energetic elliptical orbit and use SEP to spiral out to NRHO. For this option, analysis is completed to understand the trades between delivered mass to NRHO, total propellant required, time of flight, and solar array degradation. Results show that, while launching to lower altitudes can deliver greater payload mass to NRHO, significant solar array degradation can be observed.
    Keywords: Astrodynamics
    Type: GRC-E-DAA-TN59588 , AIAA Astrodynamics Specialist Conference 2018; Aug 19, 2018 - Aug 23, 2018; Snowbird, UT; United States
    Format: application/pdf
    Location Call Number Expected Availability
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    NASA TECHNICAL REPORTS
  • 6
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    Analysis of Cislunar Transfers from a Near Rectilinear Halo Orbit with High Power Solar Electric Propulsion (2018)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: As government and commercial interest in the exploration of the Moon and cislu- nar space has grown, Near Rectilinear Halo Orbits (NRHOs) have shown to be of particular interest as staging orbits for human exploration of the Moon. Once in such staging orbits, low thrust solar electric propulsion (SEP) can enable efficient transfer to other orbits in cislunar space. This paper captures ongoing analysis to design efficient transfers of a massive spacecraft from a L2 Southern NRHO to a Distant Retrograde Orbit, L1 Northern NRHO, and Flat L2 Halo Orbit using low thrust SEP. For each transfer type, reference transfer is designed for an assumed 39 t spacecraft with 26.6 kW SEP system. For each reference transfer, analysis is completed to understand the sensitivity of the transfer to changes in initial mass and SEP power and identify the optimal number of thrusters to use for a given combination of mass and power.
    Keywords: Astrodynamics
    Type: GRC-E-DAA-TN59586 , AIAA Astrodynamics Specialist Conference 2018; Aug 19, 2018 - Aug 23, 2018; Snowbird, UT; United States
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 7
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    Overview of the Mission Design Reference Trajectory for NASA's Asteroid Redirect Robotic Mission (2017)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: The National Aeronautics and Space Administration's (NASA's) recently cancelled Asteroid Redirect Mission was proposed to rendezvous with and characterize a 100 m plus class near-Earth asteroid and provide the capability to capture and retrieve a boulder off of the surface of the asteroid and bring the asteroidal material back to cislunar space. Leveraging the best of NASA's science, technology, and human exploration efforts, this mission was originally conceived to support observation campaigns, advanced solar electric propulsion, and NASA's Space Launch System heavy-lift rocket and Orion crew vehicle. The asteroid characterization and capture portion of ARM was referred to as the Asteroid Redirect Robotic Mission (ARRM) and was focused on the robotic capture and then redirection of an asteroidal boulder mass from the reference target, asteroid 2008 EV5, into an orbit near the Moon, referred to as a Near Rectilinear Halo Orbit where astronauts would visit and study it. The purpose of this paper is to document the final reference trajectory of ARRM and the challenges and unique methods employed in the trajectory design of the mission.
    Keywords: Cybernetics, Artificial Intelligence and Robotics; Astrodynamics
    Type: AAS 17-585 , GRC-E-DAA-TN44883 , AAS/AIAA Astrodynamics Specialist Conference; Aug 20, 2017 - Aug 24, 2017; Stevenson, WA; United States
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 8
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    Implicit Formulations of Bounded-Impulse Trajectory Models for Preliminary Interplanetary Low-Thrust Analysis (2020)
    In:  CASI
    Details
    Publication Date: 2020-01-16
    Description: The bounded-impulse approach to low-thrust interplanetary trajectory optimization is widely used. In an effort to efficiently implement this approach using NASAs OpenMDAO optimization software, the authors have implemented implicit formulations of the forward shooting/backwards-shooting methods commonly used in bounded-impulse models. These implicit approaches allow for vectorization of the underlying calculations which can significantly reduce runtime in interpreted languages. An implicit approach may be either converged by using an underlying nonlinear solver to converge the state propagation, or as a constraint in an optimizer-driven multiple-shooting approach. Significant computational efficiency gains are realized through the utilization of the modular approach to unified derivatives. Further computational efficiency is achieved by capitalizing on the sparsity of the constraint Jacobian matrix. This work demonstrates that a vectorized multiple-shooting approach for propagating a state-time history is superior in terms of computational efficiency as the number of segments in the state-propagation is increased.
    Keywords: Numerical Analysis
    Type: AIAA 2020-2185 , GRC-E-DAA-TN75788 , AIAA Scitech 2020 Forum; Jan 06, 2020 - Jan 10, 2020; Orlando, FL; United States
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 9
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    Sensitivity of the Asteroid Redirect Robotic Mission (ARRM) to Launch Date and Asteroid Stay Time (2017)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: National Aeronautics and Space Administrations (NASAs) proposed Asteroid Redirect Mission (ARM) is being designed to robotically capture and then redirect an asteroidal boulder mass into a stable orbit in the vicinity of the moon, where astronauts would be able to visit and study it. The current reference trajectory for the robotic portion, ARRM, assumes a launch on a Delta IV H in the end of the calendar year 2021, with a return for astronaut operations in cislunar space in 2026. The current baseline design allocates 245 days of stay time at the asteroid for operations and boulder collection. This paper outlines analysis completed by the ARRM mission design team to understand the sensitivity of the reference trajectory to launch date and asteroid stay time.
    Keywords: Astrodynamics
    Type: GRC-E-DAA-TN38898 , AAS/AIAA Space Flight Mechanics Meeting; Feb 05, 2017 - Feb 09, 2017; San Antonio, TX; United States
    Format: application/pdf
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    NASA TECHNICAL REPORTS
  • 10
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    Sensitivity of the Asteroid Redirect Robotic Mission (ARRM) to Launch Date and Asteroid Stay Time (2017)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: National Aeronautics and Space Administrations (NASAs) proposed Asteroid Redirect Mission (ARM) is being designed to robotically capture and then redirect an asteroidal boulder into a stable orbit in the vicinity of the moon, where astronauts would be able to visit and study it. The current reference trajectory for the robotic portion, ARRM, assumes a launch on a Delta-IV H in the end of the calendar year 2021, with a return for astronaut operations in cislunar space in 2026. The current baseline design allocates 245 days of stay time at the asteroid for operations and boulder collection. This paper outlines analysis completed by the ARRM mission design team to understand the sensitivity of the reference trajectory to launch date and asteroid stay time.
    Keywords: Lunar and Planetary Science and Exploration; Astronautics (General)
    Type: GRC-E-DAA-TN39169 , AAS/AIAA Space Flight Mechanics Meeting; Feb 05, 2017 - Feb 09, 2017; San Antonio, TX; United States
    Format: application/pdf
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