Reducing spacecraft thruster plume contamination using convex optimization

Commercialization of space has opened the door to a multitude of possibilities for on-orbit servicing, assembly and manufacturing missions. Rendezvous, proximity operations and docking are key elements of such missions, and extreme care must be taken to avoid thruster plume contamination of delicate sensors or payloads onboard either vehicle. In this paper we present a thorough investigation into the key sources of contamination for chemical and electric thrusters operating in close proximity to another vehicle. We develop first order plume models, to approximate thruster induced contamination, for use in our trajectory planning simulations. Fuel-optimal approach trajectories from the chaser/servicer satellite to the target/client satellite are computed using convex optimization, where the Clohessy-Wilteshire equations are used to represent the system dynamics. We then re-solve the problem while restricting the thruster pointing region by formulating a non-convex pointing constraint. This constraint is incorporated using a successive approximations method and leads to converged trajectories that reduce contamination of designated areas on the target vehicle, while keeping the required ∆V for the maneuver relatively low compared with the unconstrained problem. As expected, results confirm that incorporating this pointing constraint into the convex optimization problem leads to trajectories that are significantly more fuel efficient than those where an arbitrary non-optimal pointing constraint is simply enforced at specific times to avoid contamination.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Aerospace Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2023

Author dc:creator

• Panag, Himmat Singh

Contributors dc:contributor

• Woollands, Robyn

• Convex Optimization
• Plume Contamination
• Thruster Pointing Constraints
• Successive Approximations

Statement dc:rights

• Copyright 2023 Himmat Panag

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/120145

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F120145