Development of Supersonic Retro-Propulsion for Future Mars Entry, Descent, and Landing Systems

Abstract

Recent studies have concluded that Viking-era entry system technologies are reaching their practical limits and must be succeeded by new methods capable of delivering large payloads (> 10 metric tons) required for human exploration of Mars. One such technology, termed Supersonic Retro-Propulsion, has been proposed as an enabling deceleration technique. However, in order to be considered for future NASA flight projects, this technology will require significant maturation beyond its current state. This paper proposes a roadmap for advancing the component technologies to a point where Supersonic Retro-Propulsion can be reliably used on future Mars missions to land much larger payloads than are currently possible using Viking-based systems. The development roadmap includes technology gates that are achieved through testing and/or analysis, culminating with subscale flight tests in Earth atmosphere that demonstrate stable and controlled flight. The component technologies requiring advancement include large engines capable of throttling, computational models for entry vehicle aerodynamic/propulsive force and moment interactions, aerothermodynamic environments modeling, entry vehicle stability and control methods, integrated systems engineering and analyses, and high-fidelity six degree-offreedom trajectory simulations. Quantifiable metrics are also proposed as a means to gage the technical progress of Supersonic Retro-Propulsion. Finally, an aggressive schedule is proposed for advancing the technology through sub-scale flight tests at Earth by 2016.

Supersonic Retropropulsion Validation Experiment in the NASA Langley Unitary Plan Wind Tunnel

“…SRP has been one of the focus areas of several EDLrelated projects. For further discussions of SRP from a systems analysis and performance perspective, see [1][2][3][4][5]. A broader survey of the literature is provided in [6].…”

Propulsion System Design for a Martian Atmosphere-Breathing Supersonic Retropropulsion Engine

“…The I SP of the SRP vehicle, 370s, was based off a typical liquid oxygen, liquid methane engine. 2,16 The performance of the AB-SRP engine was based off the equilibrium combustion simulation results and estimated an I SP of 120s or 160s at OF = 4 and I SP of 160s at OF = 2. An I SP of 120s seemed reasonable for the M = 1 trajectory point and I SP = 160s seemed attainable for M = 4 or higher trajectory points.…”

“…For example, a SRP vehicle to land humans on Mars (40 MT payload) is expected to require 12 MT of propellant, 2.5 MT of fuel and 9.5 MT of oxidizer. 2 Because of this propellant mass required, currently proposed SRP configurations require a significant increase in performance before they will be seriously considered for Mars missions.…”

Tapping the Brake for Entry, Descent, and Landing

“…Supersonic retro-propulsion is a proposed solution to landing high mass to the Martian surface. 1 It addresses limitations of current systems to engage sufficient aerodynamic drag to land masses of order 10 metric tons or greater. Recent studies involving experimental 2, 3 and computational 4 simulations have been engaged to better understand capabilities and limitations of this approach.…”