← Back to Sessions

Examining Acoustic Arrivals From the OSIRIS-REx Capsule Reentry Recorded on a Large-N Infrasound Array

Description: 

Artificial object reentry from interplanetary space at speeds exceeding the escape velocity of Earth are exceptionally rare. Sources of this type that scientists have detailed foreknowledge of, including a well-constrained reentry trajectory, touchdown location, and accurately defined physical parameters is something that has only happened a handful of times since the end of the Apollo era. Meeting all of these requirements made the OSIRIS-REx sample return capsule (SRC) reentry on September 24, 2023 and its subsequent landing in Utah a singularly important event. In this study, we investigate low frequency acoustic signals generated by the SRC as it passed over a large-N infrasound array. This densely packed 121 element array was deployed across a 100 m² area at the Eureka Airport in Nevada, nearly directly under the point of maximum heating (and therefore maximum acoustic energy) of the OSIRIS-REx SRC. We first confirm that a signal from the SRC is present across the entire array, and constrain frequency content, duration, and waveform shape variability across different array elements. We then conduct statistical analyses of beamformed detections from a broad range of subarrays within the large-N configuration to determine differences in detection quality between array shapes and sizes. Our goal is to determine how much information can be gleaned about the rapidly changing backazimuth of the SRC in relation to the array using various subarrays. Additionally, we work to ascertain the incidence angle of the SRC’s acoustic pulse as it travels across the array via atmospheric temperature profiles and apparent trace velocity. To better understand the capabilities of the experimental instruments that large-N data is recorded on, we complete a comparative analysis with infrasound signals recorded on Hyperion sensors, which have well-constrained instrument response curves and dynamic ranges.

SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.

Session: Exploring Planetary Interiors and Seismology: Observations, Models, Experiments and Future Missions - I

Type: Oral

Date: 4/17/2025

Presentation Time: 09:00 AM (local time)

Presenting Author: Nora

Student Presenter: No

Invited Presentation: 

Poster Number:

Authors