Optimal finite-thrust Trans-Earth Injection (TEI) maneuvers for a Low Lunar Orbit (LLO) earth return mission
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Authors
Wheatley, Omar J.
Subjects
Optimal Control; Singular Arc; Pontryagin's Principle; Bellman's Principle; pseudospectral;
Advisors
Ross, I. Michael
Kang, Wei
Date of Issue
2010-12
Date
December 2010
Publisher
Monterey, California. Naval Postgraduate School
Language
Abstract
Pseudospectral methods are used to efficiently solve complex, non-linear optimal control problems and can be used to develop rapid and robust control solutions in astrodynamics applications. With the renewed efforts in resuming future manned missions to the moon or near-earth asteroids, fuel optimal flight trajectories are desired in order to alleviate the need for overestimates in fuel carried onboard, which has a negative impact on the overall spacecraft design. This thesis uses a pseudospectral optimal control solver, DIDO, to solve for a fuel optimal moon-to-earth trajectory using only the auxiliary engines of the Orion Crew Exploration Vehicle (CEV) for the entire mission. Additionally, higher-order necessary conditions are examined to test the extremality of the computed solution. Singular arcs that appear in a main engine variable thrust, fuel optimal trajectory are examined by applying the Bellman Pseudospectral method. The feasibility of using the CEV auxiliary engines in place of the main engines for the singular arc maneuver is also investigated.
Type
Description
Series/Report No
Department
Applied Mathematics
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
Format
xiv, 113 p. : col. ill. ; 28 cm.
Citation
Distribution Statement
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.