NASA Requirements and Applications Environments for Electrical Power Wiring

Fire safety in spacecraft: Past incidents and Deep Space challenges

“…The electrical nature of the failures also highlights the lack of understanding of overheating mechanisms in this context. Later investigations revealed that high humidity had led to either shorts [50], or hydrolytic degradation of wire insulation allowing electric arcs to propagate along wiring bundles and degrade the insulating material in the process [51]. It is supposed that degradation never led to ignition of Kapton polyimide (MIL-W-81381), which had been picked as wiring insulation in the Shuttle for, among other properties, its non-flammability at normal gravity [52].…”

“…Later investigations revealed that high humidity had led to either shorts [50], or hydrolytic degradation of wire insulation allowing electric arcs to propagate along wiring bundles and degrade the insulating material in the process [51]. It is supposed that degradation never led to ignition of Kapton polyimide (MIL-W-81381), which had been picked as wiring insulation in the Shuttle for, among other properties, its non-flammability at normal gravity [52]. However, the rationale for extrapolating normal gravity data to spacecraft configuration had still not been systematically investigated, meaning Test 1 might generate an inadequate database.…”