In-situ detection of micrometeoroids and orbital debris: The PIE experiment on MIR Original Research Article

During the last few years, investigation of impact features found on material retrieved after exposure to space for a long period of time, in low earth orbits, has provided us with a great deal of data on the particulate environment, either natural or man-made. The PIE detection device presented here has been deployed outside the Kvant-2 module attached to the Russian MIR station, between June 1996 and April 1997. Part of the experiment uses a detection technique similar to the one used in previous experiments flown on LDEF and MIR. Passive sensors are composed primarly of stacked thin metal foils (gold and aluminium). According to the size of the particles, they are either decelerated or fragmented upon high velocity impact. The size of holes or impact craters give information on the size or shape of the impacting particles. Samples have been retrieved for laboratory analysis. Comparison with data from LDEF, EuReCa, HST and previous experiments on MIR provides insight in the long term evolution of small particle population and in the debris environment of a permanently manned station. Some of the samples show evidence of secondary impact cratering: an attempt is made to locate the origin of the primary impact site. Some results about the possible origin of the impactors are provided by the chemical identification of particle remnants inside the craters.