Initial Results from the BOLT Flight Experiment

Abstract

View Video Presentation: https://doi.org/10.2514/6.2022-0345.vid The Boundary Layer Transition (BOLT) flight experiment was designed to study hypersonic boundary-layer transition on a geometry with low-curvature concave surfaces and highly-swept leading edges. The launch of the vehicle occurred at 0250 CEST local time (0050 UTC) on 23 June 2021. Shortly after launch, the flight vehicle exhibited unexpected aerodynamic behavior by entering into a coning motion at relatively large angles of attack. While the BOLT experiment did not reach its intended Mach 5-7 conditions in flight, the experiment did gather potentially useful boundary-layer transition measurements at supersonic conditions (Mach 2-4), primarily during the descent phase of flight. This paper will present a preliminary analysis of boundary-layer transition inferred from the data from these sensors during the supersonic descent, although at present there is uncertainty regarding the precise vehicle attitude behavior during descent.