Using fireball networks to track more frequent reentries: Falcon 9 upper stage orbit determination from video recordings

TL;DR

This paper demonstrates how fireball detection networks can be used to track and analyze artificial reentry objects like Falcon 9 upper stages from video recordings, enhancing space debris monitoring.

Contribution

It adapts meteoroid trajectory analysis methods for slow, curved artificial object reentries and validates results with government catalog data.

Findings

Successful orbit determination of Falcon 9 upper stage from video data

Identification of potential hazard zones for reentry debris

Highlighting the role of fireball networks in space debris monitoring

Abstract

On February 16, 2021, an artificial object was recorded by the Spanish Meteor Network (SPMN) moving slowly over the Mediterranean. From the astrometric measurements, we identify this event as the reentry engine burn of a SpaceX Falcon 9 launch vehicle's upper stage. To study this event in detail, we adapted the plane intersection method for near-straight meteoroid trajectories to analyze slow and curved orbits associated with artificial objects. To corroborate our results, we approximated the orbital elements for the upper stage using four pieces of "debris" cataloged by the U.S. Government Combined Space Operations Center (CSpOC). Based on these calculations, we also estimated the possible deorbit hazard zone using the MSISE90 model atmosphere. We warn of the interference that these artificial bolides might have in fireball studies. In addition, given that artificial bolides will be probably more frequent in the future, we point out the new role that ground-based detection networks can play in the monitoring of potentially hazardous artificial objects in near-Earth space and determining the strewn field of artificial space debris.