Files in this item



application/pdfLORENZ-THESIS-2017.pdf (2MB)
(no description provided)PDF


Title:Hypersonic flight strategies for supersonic retropropulsion at Mars
Author(s):Lorenz, Christopher George
Advisor(s):Putnam, Zachary R
Department / Program:Aerospace Engineering
Discipline:Aerospace Engineering
Degree Granting Institution:University of Illinois at Urbana-Champaign
Entry, descent, and landing (EDL)
Optimal control
Space systems
Supersonic retropropulsion
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.
Issue Date:2017-04-25
Rights Information:Copyright 2017 Christopher G. Lorenz
Date Available in IDEALS:2017-08-10
Date Deposited:2017-05

This item appears in the following Collection(s)

Item Statistics