Hypersonic flight strategies for supersonic retropropulsion at Mars

Future large-scale Mars surface exploration missions require landed masses beyond the capability of current entry, descent, and landing technology. High-mass missions will likely use supersonic retropropulsion to increase landed mass, a paradigm shift from current supersonic parachute systems. This work explores hypersonic flight strategies appropriate for use with supersonic retropropulsion systems at Mars. Optimal control techniques are used to determine hypersonic bank-angle profiles that achieve favorable supersonic retroprolusion ignition states. Bang-bang control in the hypersonic flight regime is shown to be optimal for targeting specific state values at terminal descent initation and for minimizing propellant use during propulsive descent. A trade-off between altitude and flight-path angle at supersonic retropropulsion ignition is identified. Minimum-propellant propulsive descent trajectories are identifed and studied parametrically. Results show that hypersonic ballistic coefficient and lift-to-drag ratio have the largest effects on minimum propellant mass fraction; changes to the vehicle state at entry interface have a smaller effect. The space of reachable supersonic retropropulsion ignition states is presented over a range of vehicle and trajectory parameters of interest. Results indicate execution of an appropriate hypersonic flight strategy can significantly reduce the amount of propellant required for supersonic retropulsion systems performing powered descent and landing at Mars.

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

2017

Author dc:creator

• Lorenz, Christopher George

Contributors dc:contributor

• Putnam, Zachary R.

• Mars
• Entry, descent, and landing (EDL)
• Optimal control
• Space systems
• Supersonic retropropulsion
• Hypersonic

Statement dc:rights

• Copyright 2017 Christopher G. Lorenz

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/97453

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/97453