High-fidelity low-thrust trajectory optimization to the lunar gateway

Patrick, Brian Christopher

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https://hdl.handle.net/2142/120148 Copy

Description

Title

High-fidelity low-thrust trajectory optimization to the lunar gateway

Author(s)

Patrick, Brian Christopher

Issue Date

2023-05-02

Director of Research (if dissertation) or Advisor (if thesis)

Woollands , Robyn

Department of Study

Aerospace Engineering

Discipline

Aerospace Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Aerospace Engineering
• Low-Thrust Trajectory Optimization
• Indirect Optimization
• Lunar Gateway
• High-Fidelity

Abstract

In recent years, there has been growing interest from NASA and other organizations to establish a prolonged presence in orbit around and on the surface of, the moon. Initiatives such as the Artemis program and the development of the lunar space station, colloquially known as “Gateway”, will require efficient transfers to and from the Moon. Solar electric propulsion will play a key role in designing energy-efficient transfers that maximize the payload delivery to and from Gateway. As such, there is a growing need for the development and advancement of innovative tools that are capable of efficiently designing low-thrust transfers in Cislunar space. One method to aid in the design of these highly efficient transfers is to utilize the long-duration coast arcs, the result of the natural dynamics of multi-body gravitational systems. In this work, ephemeris perturbed invariant manifold “analogs” are utilized to compute end-to-end transfers to Gateway for 500kg and 1000kg spacecraft. To reduce the computational overhead required to solve for all possible transfers to the manifolds, a comprehensive analysis of the manifold trajectories is carried out to pre-filter many of the less favorable options and determine boundary conditions for the optimal control problem. Minimum-fuel and minimum-time optimal control policies are formulated using indirect methods derived from Optimal Control Theory (OCT). Fuel-optimal, low-thrust transfers from a Geosynchronous Equatorial Orbit (GEO) to Gateway’s near rectilinear halo orbit (NRHO) are computed using three methods, namely the “Strictly Optimal”, “Patched”, and “Hybrid Optimization” methods. Considering a spacecraft with thrust acceleration in the range of 0.20−0.50 mm/s2, such problems are extremely challenging to solve with single or multiple-shooting, even when continuation and smoothing are applied to thruster ON/OFF switches and eclipse entry/exit conditions. Our Hybrid Optimization scheme is formulated using particle swarm optimization (PSO) to compute the optimal sequence of intermediate target orbits between the departure orbit and the desired manifold injection point, such that the total propellant mass for the transfer is minimized. To quantify the performance of our hybrid algorithm, we compare it to optimal trajectories obtained using single or multiple-shooting for problems with a larger thrust-to-weight ratio that can be more easily converged by using shooting methods.

Graduation Semester

2023-05

Type of Resource

Thesis

Copyright and License Information

Copyright 2023 Brian Patrick

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