Study on Prefire Phenomena of Wire Insulation at Microgravity

The experimental hardware was developed to perform the experiments of prefire characteristics of wire insulation caused by overload on board the SJ-8 China recoverable satellite. In the experiments, the prefire characteristics including the temperature and radiation characteristics of the wire insulations were presented. The temperature histories of the wire insulation in microgravity and the low-pressure environment in normal gravity were obtained. Effects of overloaded currents on the fire initiation were investigated for different wire coiled states. The results indicate that the natural convection almost vanished and the heat loss of the electric components decreased in the microgravity environment. It might cause overheating of the electric components and then results in fire, and thus the fire risks of wire in the microgravity condition are much more dangerous than that in normal gravity under the condition of overload.