An RLV-Based Plume Impingement Test Bed: Terrestrial Evaluation of Landing Pads Constructed of Granular Materials

Uncertainty regarding the consequences of a rocket engine's plume interaction with a landing surface is a fundamental challenge posed by extraterrestrial vehicle landings. Prior research has established that a vehicle's landing thrusters can undermine the stability of the landing surface, putting the exploration vehicle at risk of an off-nominal landing or an altogether mission loss - this is known as "the plume problem." Analysis and experimentation have yielded several categories of design solutions to the plume problem through various treatments or configurations of the surface to create a landing pad using in situ materials. In support of research to enable missions to other celestial bodies, the authors have developed the Plume Impingement Test Bed (PITB) to provide a means of i) gathering data relating to plume effects upon prepared and unprepared soil media and ii) evaluating the effectiveness of design solutions to the plume problem. The PITB provides a terrestrial means of evaluating realistic plume effects by incorporating a flight-rated reusable launch vehicle (RLV), equipped with a liquid-propellant rocket engine. The PITB combines a Masten Space Systems, Inc. (Masten) vertical take-off and vertical landing (VTVL) RLV with a suite of instruments and a procedural framework to gather data and characterize the effects of a plume's interaction with a surface. The PITB is well-equipped to evaluate landing surfaces that have been prepared using robotic or other experimental methods to stabilize a surface for use as a landing pad. In operation, the instrumentation suite is deployed at a test site, calibrated and then the test surface is exposed to the VTVL RLV rocket plume. This paper will describe the design, operations and capabilities of the PITB.