Payload mass improvements of supersonic retropropulsive flight for human class missions to Mars

• Main Author: Fagin, Maxwell H.
• Language: EN
• Published: Purdue University 2016
• Subjects: Aerospace engineering
• Online Access: http://pqdtopen.proquest.com/#viewpdf?dispub=10046736

<p> Supersonic retropropulsion (SRP) is the use of retrorockets to decelerate during atmospheric flight while the vehicle is still traveling in the supersonic/hypersonic flight regime. In the context of Mars exploration, <i>subsonic</i> retropropulsion has a robust flight heritage for terminal landing guidance and control, but all <i>supersonic</i> deceleration has, to date, been performed by non-propulsive (i.e. purely aerodynamic) methods, such as aeroshells and parachutes.</p><p> Extending the use of retropropulsion from the subsonic to the supersonic regime has been identified as an enabling technology for high mass humans-to-Mars architectures. However, supersonic retropropulsion still poses significant design and control challenges, stemming mainly from the complex interactions between the hypersonic engine plumes, the oncoming air flow, and the vehicle&rsquo;s exterior surface. These interactions lead to flow fields that are difficult to model and produce counter intuitive behaviors that are not present in purely propulsive or purely aerodynamic flight.</p><p> This study will provide an overview of the work done in the design of SRP systems. Optimal throttle laws for certain trajectories will be derived that leverage aero/propulsive effects to decrease propellant requirements and increase total useful landing mass. A study of the mass savings will be made for a 10 mT reference vehicle based on a propulsive version of the Orion capsule, followed by the 100 mT ellipsoid vehicle assumed by NASA&rsquo;s Mars Design Reference Architecture.</p>