The chemistry of micrometeoroid and space debris remnants captured on Hubble Space Telescope solar cells

Prior to the retrieval in 1993 from low Earth orbit (LEO), the " -V2" Solar Array wing of the Hubble Space Telescope was exposed to hypervelocity impacts (micrometre to millimetre scale) from both micrometeoroids and space debris. The initial survey of the damage (100-3500mum diameter sized craters) identified that micrometeoroid remnants dominated the flux in the 100-1000mum size regime, with debris dominating >1000mum. These residues were composed of remnants of silicate minerals, calcite, metal sulfides and metals that often appeared as complex poly-mineralic melts within melt pits. A further survey of 10-100mum diameter craters identified that the most common chemistry was space debris with the crossover from meteoroids to debris being at around 30mum D-CO. Residues include remnants of specialised steels and paint fragments but the dominant type is aluminium and aluminium oxide, which are almost certainly remnants of solid rocket motor operations. It is found that the relative contribution of debris as a function of size, agrees remarkably with a prediction derived using flux data from Long Duration Exposure Facility and a meteoroid model. (C) 2001 Elsevier Science Ltd. All rights reserved.