A space debris impact detector for the UNISAT microsatellite

UNISAT is a microsatellite developed with didactical purposes at the University of Rome by the Group of Astrodynamics (GAUSS). One of the payloads onboard the satellite should be an impact sensor for detection of natural and artificial microparticles colliding with the spacecraft. The use of different kinds of piezoelectric impact sensors is presently being investigated and test sessions have started to select the best candidate. Such a selection can happen not to have an unique solution: for detection of very small particles (some 1 mum) probably we need to use an external sensor characterised by an "active" material directly exposed to the debris environment; as the greatest part of the satellite surface will be covered by solar panels, this kind of sensor could only count on a small detection area (to say some square decimetres). On the other hand, it is possible to put a certain number of piezoelectric devices on the internal surfaces of UNISAT. The goal is to have a sensible area as great as the total spacecraft surface, but the cost is a lower sensitivity of the piezoelectric sensors, possibly resulting in being able to detect only particles well above 1 mum size.