Supersonic Flight Test Of The SIAD-R: Supersonic Inflatable Aerodynamic Decelerator for Robotic Missions to Mars

Abstract

An inflatable supersonic decelerator that enables p ayloads larger than the Mars Science Lab to be delivered to the surface of Mars has been developed. This decelerator, the SIAD- R, underwent a full-scale suborbital supersonic tes t flight in 2014. During that flight, the SIAD-R deployed at roughly Mach 4.1 at a dynamic pressure of 350 Pa. The SIAD-R performed flawlessly throughout this test flight an d has achieved Technology Readiness Level 6. This paper describes the test flight envir onment and the response of the SIAD-R to the test flight environment. Specifically, characte rization of the SIAD-R deployment, the inflation pressure of the SIAD-R, and the aeroelast ic distortion of the SIAD-R were measured and recorded during the flight and are discussed. Notably, the approximate proportionality of SIAD-R aeroelastic distortion to the ratio of dynamic pressure to SIAD-R inflation pressure that had been previously identif ied in subsonic testing was also found to be valid during in this supersonic test flight; this a pproximation allows for extrapolation of the aeroelastic distortion under a dynamic pressure of 2200 Pa even though this dynamic pressure was not achieved during the 2014 test flig ht. This paper also discusses the current design of the SIAD-R, with the emphasis on the inte rfaces to the supersonic test flight vehicle and design updates that have been made to the SIAD-R following the completion of subsonic testing and vacuum chamber inflation testing.