EUROPE CONTRIBUTION TO THE LONG-DURATION EXPOSURE FACILITY (LDEF) METEOROID AND DEBRIS IMPACT ANALYSIS

The near-Earth space is increasingly populated with operational spacec raft and space debris that could become a serious hasard to future spa ce activities. To gain more information on small debris and meteoroids , surfaces and materials that have been exposed to the space environme nt are analysed after their return to ground. To further study that en vironment, NASA's Long Duration Exposure Facility (LDEF) spent 68 mont hs in low Earth orbit. About 34 000 'impact records' have been identif ied; their size ranges from a few microns to several millimetres. Seve ral European laboratories and institutes are analysing the material an d data collected. Some areas being investigated are the distribution a nd statistics of impacts, the morphology of impact features, the speed of impact and the chemical composition of the impacting particles, an d the improvement of current debris and meteoroid models. The experien ce gained with LDEF is of paramount importance for the post-flight inv estigation of ESA's Eureca satellite and the solar arrays that will be returned from the Hubble Space Telescope in December.