Seismoacoustic measurements of the OSIRIS-REx re-entry with an off-grid Raspberry PiShake

Abstract

Hypersonic re-entries of spacecraft are valuable analogues for the identification and tracking of natural meteoroids re-entering the Earth's atmosphere. We report on the detection of seismic and acoustic signals from the OSIRIS-REx landing sequence, acquired near the point of peak capsule heating and recorded using a fully off-grid Raspberry PiShake sensor. This simple setup is able to record all the salient features of both the seismic and acoustic wavefields; including the primary shockwave, later reverberations, and possible locally induced surface waves. Peak overpressures of 0.7 Pa and ground velocities of 2x10-6m/s yield lower bound on the air-to-ground coupling factor between 3 and 44 Hz of 1.4x10-6 m/s/Pa, comparable to results from other re-entries