Entry Dispersion Analysis for the Hayabusa Spacecraft using Ground Based Optical Observation

TL;DR

This paper evaluates ground-based optical observations as a reliable backup method for predicting the reentry landing dispersion of the Hayabusa spacecraft, demonstrating its effectiveness without active spacecraft involvement.

Contribution

It introduces a novel analysis of optical observation as a backup navigation method for reentry, comparing scenarios to assess accuracy and dispersion.

Findings

Optical observations can effectively predict reentry landing zones.

Ground-based optical observation provides a steady backup without spacecraft input.

Reentry dispersion estimates improve backup navigation reliability.

Abstract

Hayabusa asteroid explorer successfully released the sample capsule to Australia on June 13, 2010. Since the Earth reentry phase of sample return was critical, many backup plans for predicting the landing location were prepared. This paper investigates the reentry dispersion using ground based optical observation as a backup observation for radiometric observation. Several scenarios are calculated and compared for the reentry phase of the Hayabusa to evaluate the navigation accuracy of the ground-based observation. The optical observation doesn't require any active reaction from a spacecraft, thus these results show that optical observations could be a steady backup strategy even if a spacecraft had some trouble. We also evaluate the landing dispersion of the Hayabusa only with the optical observation.