Hayabusa2 Capsule Reentry: Australian Airborne Observation Emission Spectroscopy Calibration and Preliminary Analysis

This paper describes the preliminary analysis of Hayabusa2 capsule reentry data obtained from two spectrometers ('Hyper-Mono-1' and 'Hyper-IR-1') onboard the Australian Airborne Reentry Observation Mission. The image processing techniques and spectrometer calibration methodology are presented, with a methodology for defining the premium-quality frames developed. A single-temperature Planck curve was fit to the measured spectra to determine the apparent temperature of the Hayabusa capsule, as observed from 17:29:01 UTC to 17:29:22 UTC on December 5th 2020. The methods presented herein will be applied for the analysis of the data collected from an additional six spectrometers designed and operated by the University of Southern Queensland, which were used to collect data of the Hayabusa2 capsule reentry from 17:28:58 UTC to 17:29:28 UTC. The peak measured apparent temperature that was determined using the two spectrometers described herein was approximately 2760 K ± 75 K at approximately 17:29:10 UTC. The apparent capsule temperature was measured to reduce from approximately 2700 K to approximately 2200 K from 17:29:13 UTC to 17:29:21 UTC