Laboratory investigations of impact residues captured on the solar cells from the Hubble Space Telescope and on insulation foils from the Space Flyer Unit demonstrate preservation of abundant and diverse micrometeoroid and space debris remnants. Micrometeoroid residues often appear as complex melts of poly-mineralic origin derived from silicates, carbonates, metals and metal sulfides. The space debris includes paint-flakes, metal alloys and possible reactor coolant, but the most abundant components are aluminium and aluminium oxide remnants from solid rocket motor operation. The impactor origins have now been compared with the theoretical flux models for Low Earth Orbit.
Our understanding of small particle populations has been aided by laboratory investigations of cosmic dust particles (approximately 1-400μm diameter). Such studies have focused mainly on material collected from 'terrestrial' locations, e.g. the ocean floor, polar ices and the stratosphere, e.g. However, these particles may have undergone selection and alteration during atmospheric entry, e.g., and it is desirable to achieve some sampling outside of the Earth's atmosphere. The Giotto spacecraft investigated particles from Comet Halley using a dust-impact detection system, but did not return samples for further examination. Particle analysers have flown on several interplanetary and earth orbital missions.