Propulsion System Design for a Martian Atmospheric Breathing Supersonic Retropropulsion Engine
Author(s)
Gonyea, Keir C.
Braun, Robert D.
Advisor(s)
Editor(s)
Collections
Supplementary to:
Permanent Link
Abstract
Design and analysis was performed on an atmospheric breathing propulsion system to
land large-scale spacecraft on Mars. Initial feasibility of the engine was investigated
analytically by employing equilibrium combustion and finite rate kinetics simulations in
addition to 1st order propellant mass and inlet sizing. ISP values (based on total propellant
usage) were determined to be on the order of 120s-160s for onboard subsystems having a 10-
to-1 oxidizer compression ratio. This corresponds to an ISP of 600s-800s based on fuel
consumption. While Mg-CO2 mixtures have significant ignition constraints, favorable
conditions were found, yielding ignition delay times of less than 1ms, by simultaneously
employing designs exploiting both large reentry Mach numbers and modest compression
ratios. These combinations allow for combustion to occur within moderately sized
combustion chambers. The 1st order sizing calculations confirmed that atmospheric
breathing supersonic retropropulsion has the potential for significant mass savings over
traditional retropropulsion architectures. Engines sized with an oxidizer-to-fuel ratio of 4
require half the propellant consumption for an equivalent change in velocity. Inlet capture
areas of the examined atmospheric breathing propulsion systems were on the order of the
corresponding entry vehicle projected area. Therefore, this study envisioned an annular inlet
design, which encircled the vehicle forebody. The aforementioned analyses address some of
the challenges that need to be solved in order to ultimately obtain a practical atmospheric
breathing supersonic retropropulsion system for Mars descent.
Sponsor
Date
2014-06
Extent
Resource Type
Text
Resource Subtype
Paper
Rights Statement
Unless otherwise noted, all materials are protected under U.S. Copyright Law and all rights are reserved