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

Abstract

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 and ascent databases. The liftoff/transition database was developed using 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 the NASA Langley Unitary Plan Wind Tunnel. The A106 vehicle 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.

Estimation of Aerodynamic Stability Derivatives for Space Launch System and Impact on Stability Margins

“…Thereafter, the CP gradually shifts aft and closer to the CG. This observation is consistent with compressible aerodynamic theory 6 which suggests that the oblique shock off the vehicle nose lies closer to the body with increasing Mach number which shifts the aerodynamic loading aft. Figure 8 shows the total normal force coefficient gradient distribution along the x-axis of the vehicle at Mach 1.1 and 3.0.…”