Optimal low-thrust, Earth-Moon trajectories

Thumbnail Image
Date
1993
Authors
Kluever, Craig
Major Professor
Advisor
Bion L. Pierson
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Altmetrics
Authors
Research Projects
Organizational Units
Organizational Unit
Journal Issue
Is Version Of
Versions
Series
Department
Aerospace Engineering
Abstract

A variety of optimal trajectories from a circular low-Earth parking orbit to a circular low-lunar parking orbit are computed for a range of low-thrust spacecraft. The problem is studied in the context of the classical restricted three-body problem. Minimum-fuel, planar trajectories with a fixed thrust-coast-thrust engine sequence are computed for both a "high-end" low-thrust spacecraft and "moderate" low-thrust nuclear electric propulsion (NEP) spacecraft. Since a low-thrust trajectory is a long duration transfer with slowly developing spirals about the Earth and Moon, the minimum-fuel Earth-Moon trajectory is obtained by formulating and successively solving a hierarchy of sub-problems. The subproblems include optimal Earth-escape and Moon-capture trajectories and sub-optimal translunar trajectories. The complete minimum-fuel trajectory problem is eventually solved using a "hybrid" direct/indirect method which utilizes the benefits of a direct optimization method and an indirect method from optimal control theory. Minimum-fuel transfers are also computed using a switching function structure which results in multiple thrust and coast arcs. In addition, a new combined vehicle and trajectory optimization problem of maximum payload fraction is formulated and solved. Finally, three-dimensional minimum-fuel trajectories are obtained for both the "high-end" and "moderate" low-thrust spacecraft. Numerical results are presented for various optimal Earth-Moon trajectories.

Comments
Description
Keywords
Citation
Source
Subject Categories
Copyright
Fri Jan 01 00:00:00 UTC 1993