Development of Unsteady Aerodynamic Environments for the SLS Core Stage from High Spatial Resolution Wind Tunnel Data

Post-flight assessment of Artemis I Space Launch System (SLS) instrumentation revealed a global high vibration response that could not be represented by the existing end-to-end modeling approach. Further investigation showed this response corresponded to the vortex shedding environment created by the forward attach hardware between the SLS Core Stage and Boosters. Traditional unsteady aerodynamic environments, such as zonal maximax aeroacoustic or centerline buffet environments, were found to be insufficient representations of this vortex shedding due to its strong tonal and anti-correlated nature and its mode shape, which excited primary structure shell modes. A wind tunnel test campaign was conducted at the NASA Ames Unitary Plan Wind Tunnel (UPWT) to capture high spatial resolution unsteady aerodynamic data in the SLS multi-body region. This presentation will detail this wind tunnel test and as well as how the resulting data were developed into forcing functions that better represent this environment.