Hypersonic flight strategies for supersonic retropropulsion at Mars

Lorenz, Christopher George

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https://hdl.handle.net/2142/97453 Copy

Description

Title

Hypersonic flight strategies for supersonic retropropulsion at Mars

Author(s)

Lorenz, Christopher George

Issue Date

2017-04-25

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

Putnam, Zachary R.

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)

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

Abstract

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.

Graduation Semester

2017-05

Type of Resource

text

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

Copyright and License Information

Copyright 2017 Christopher G. Lorenz

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