An Efficient Algorithm for Computing the Low-thrust Escape Trajectory
An Efficient Algorithm for Computing the Low-thrust Escape Trajectory

Author: John A. Gall

Publisher:

Published: 2004

Total Pages: 122

ISBN-13:

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An algorithm to improve the computational efficiency of the low-thrust escape trajectory is developed. The algorithm reduces computational effort while maintaining accuracy, making it desirable for use in computing optimal escape trajectory by direct method. As low-thrust ionic propulsion engines are considered for use in interplanetary missions, design and planning includes the optimization of the spacecraft trajectory. The low-thrust escape phase evolves in the form of a slowly unwinding spiral. The computational expense required to accurately propagate the dense spiraling trajectory of the planetocentric escape phase through the numerical integration of the ordinary differential equations is undesirable. Implementation of an algorithm that approximates the trajectory while maintaining accuracy and improving computational efficiency is beneficial. The algorithm developed is demonstrated with the optimization of a sample Earth-escape trajectory. An inexpensive trajectory calculation with little error is produced.

Escape Trajectories for Low Thrust Vehicles
Escape Trajectories for Low Thrust Vehicles

Author: John Joseph Dell

Publisher:

Published: 1962

Total Pages: 117

ISBN-13:

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The escape parameters (time, range angle and position) are studied for achieving optimum escape missions using low-thrust vehicle . Results are compared with previously reported analytical and numerical calculations. The equations of motion in addition to Euler-Lagrange optimization equations were solved using an IBM 7090 Low-Thrust Digital Computer Program. Specific impulses were varied from 1,000 to 25,000 sec and electrical power outputs were varied from 100 KW to 100 MW. Planar orbits initially circular) were assumed. Results of the parametric investigation are presented both in tabular and graphical form. Analy is of generated escape data indicate that the analytical equations previously reporte have deviations ranging from approximately -25% to 44%. Numerical results previously reported are in general agreement with this study. (Author).

Optimization of Low Thrust Spacecraft Trajectories Using a Genetic Algorithm
Optimization of Low Thrust Spacecraft Trajectories Using a Genetic Algorithm

Author: Jason Corey Eisenreich

Publisher:

Published: 1998-01-01

Total Pages: 79

ISBN-13: 9781423554493

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This thesis concerns the use of genetic algorithms in the optimization of the trajectories of low thrust spacecraft. Genetic algorithms are programming tools which use the principles of biological evolution and adaptation to optimize processes. These algorithms have been found to be very useful in many different engineering disciplines. The goal of this project is to determine their applicability to the generation and optimization of low thrust spacecraft trajectories. This thesis describes the basic operating principles of genetic algorithms and then applies them to two different missions.