Acoustic Observations of the OSIRIS-REx Sample Return Capsule Re-Entry from Wendover Airport

Abstract The Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer sample return capsule (SRC) re-entered the Earth’s atmosphere at hypersonic speeds from interplanetary space on 24 September 2023. The current work reports on 18 ground-based acoustic sensors deployed at Wendover Airport, the same location that the Genesis and Stardust SRC re-entries were recorded. Four different sensors (Chaparral Physics, Gem, Wilson Engineering Research and Development [WERD], and RedVox) were deployed in close proximity to compare their performance. All the sensors captured an N-wave signal associated with the SRC re-entry shock wave followed by a broadband coda. The Chaparral Physics array served as the high-fidelity reference measurement. The N-wave signal had a peak-to-peak amplitude of 4.07 Pa with a fundamental frequency of 4.98 Hz from 167.5° measured clockwise from north, nearly perpendicular to the SRC trajectory. In addition, high coherence in the coda was shown to be associated reflections from the surrounding mountains. In general, the more economical sensors (Gem, WERD, and RedVox) produced results that were consistent with these observations and sensor specifications. Beamforming with these single sensors arranged as an array showed agreement with the high-fidelity array to within a couple of degrees. Furthermore, the current high-fidelity results were compared with the measurements during the Genesis and Stardust SRC re-entries. All three entries produced a broadband fundamental peak at a frequency that was inversely related to the SRC diameter as well as evidence of reflections from the surrounding topography.