Spectral Features for Re-entry Break-up Event Identification

TL;DR

This paper explores the use of spectral analysis to identify spacecraft breakup events during atmospheric re-entry by detecting characteristic alkali metal emissions in ground tests.

Contribution

It introduces a novel spectroscopic approach to detect aluminum alloy failure during re-entry, highlighting lithium lines as potential markers for spacecraft disintegration.

Findings

Lithium emission lines indicate aluminum alloy breakup.

Distinct alkali metal features differentiate alloy failure points.

Spectroscopic markers can improve re-entry event identification.

Abstract

The fragmentation of two aerospace aluminum alloys is investigated in a ground testing facility including mechanical loads as occurring due to aerodynamic forces in a real atmospheric entry event at three trajectory points. The emission spectroscopic analysis shows that these materials fail after distinct alkali metal features are observed in the spectra. The two alloys feature characteristic emissions of the different alkali metals. The presence of lithium lines that have previously been exclusively attributed to battery failure in observation campaigns may be considered as a marker for aluminum breakup. This is particularly interesting for future entry observations because it allows a new insight into the structural failure processes of the demising spacecraft. The lack of emission of alloying elements points to these spectra being a candidate for the determination of spacecraft demise. The identification of such features in ground testing will allow a more certain identification of specific break-up events