Aerodynamic Database Development for Lift-off/Transition and Ascent of the Ares I Vehicle

NASA Langley Research Center, in partnership with NASA Marshall Space Flight Center and NASA Ames Research Center, was involved in the aerodynamic analysis, testing, and database development for the Ares I A106 crew launch vehicle in support of the Ares design and analysis cycle. This paper discusses the development of the liftoff/transition andascent databases. The liftoff/transition databasewas developedusing data from tests on a 1.75% scale model of the A106 configuration in the NASA Langley 14 22 ft subsonic wind tunnel. The ascent database was developed using test data on a 1% A106 scale model from two different facilities, the Boeing Polysonic Wind Tunnel and theNASALangleyUnitaryPlanWindTunnel. TheA106vehicle has limited roll control authority, which in turn required that the rolling moment component in the ascent database be defined as accurately as possible, leading to increased wind-tunnel testing time. The increments in aerodynamic coefficients for differences in windtunnel and flight Reynolds numbers were estimated using computational fluid dynamics solutions. However, these increments were found to be modest.