Fault arc tests in cable bundles under microgravity conditions

This paper discusses some forms of wiring degradation and failure modes which can occur when the wiring is in operation on spacecraft. Some of the environmental conditions which will be encountered by a manned spacecraft will be introduced. In the past numerous experiments on cable bundles for space applications have been performed under different stress and environmental conditions. As part of the extensive testing, many variables were investigated such as wire gauge size, applied current and environment. Some results have been published at previous meetings as well as in publications. One major parameter, however, remained to be investigated and that is the effect of gravity on the mechanism of arcing failure. One method by which this can be studied is by making use of the opportunities offered using a parabolic flight where periods of microgravity (μg) of some 20 to 25 s can be achieved. In a μg-night campaign the effects related to this essential parameter were studied in detail. The μg-flight campaign conducted in an Airbus A300 took place in Bordeaux, France, September 1997. This paper presents results based on the performance of arcing experiments under vacuum conditions. These systematic series of tests were the first ones covering the μg-parameter under vacuum conditions to the authors knowledge