The upcoming seismo-acoustic observational campaign of an artificial meteor: The OSIRIS-Rex Sample Return Capsule re-entry

Meteoroids and asteroids are of broad scientific interest, from planetary sciences to hypersonic physics. However, impacts into the Earth’s atmosphere, especially by asteroids in a meter-size range, are sporadic and unannounced, making it impractical to plan a dedicated multi-instrument observation campaign aimed at studying and characterizing these objects. Thus, well-documented scientific observations of asteroids are rare and generally happen by chance. In these cases, many parameters of interest (e.g., composition, size, porosity, rotation, ablation rate, shock characteristics, hyperthermal chemical processes) remain poorly defined, and scientific analyses largely rely on assumptions and predictions derived from the theoretical domain. Since the end of the Apollo era, only four instances of a hypersonic re-entry of an artificial body from interplanetary space with an incident speed of 11-12 km/s have been observed and studied. These were the Sample Return Capsules (SRCs) that brought physical samples of extraterrestrial material back to Earth. Arriving from interplanetary space at hypervelocity, SRCs are considered analogues for low velocity meteoroids and asteroids impacting the Earth’s atmosphere, and as such provide unprecedented and unique opportunities to perform detailed studies of meteor phenomena, test and calibrate sensors, and validate and improve models. The next opportunity will present itself on 24 September 2023 with the re-entry of OSIRIX-REx SRC that will bring samples of the carbonaceous near-Earth asteroid Bennu. The OSIRIX-REx asteroid sample return mission was launched in 2016 with the aim to collect samples from the near-Earth asteroid Bennu and bring those samples back to Earth in pristine condition. Bennu was chosen because it is a readily accessible, primitive, carbonaceous asteroid, and it is also one of the most potentially hazardous known near-Earth objects. OSIRIX-REx SRC is identical to that of the Stardust SRC; that includes the mechanical design, and all aspects of re-entry. Landing is planned for 24 September 2023.The OSIRIX-REx re-entry presents a unique and exceptional opportunity to observe a well-defined artificial meteor, to perform detailed studies of hypersonic entry and event characterization, to test sensors, and validate and improve models. We will organize and lead multi-instrument observations of the OSIRIX-REx SRC re-entry. The instruments will include infrasound and seismic sensors strategically positioned in the immediate and extended region around the projected re-entry trajectory to maximize the scientific output. Data collected during this observational campaign will be made freely available to the broad scientific community following publication.

SNL is managed and operated by NTESS under DOE NNSA contract DE-NA000352.