THE Hubble Space Telescope is being battered as it orbits Earth. It has
suffered 571 hits from high-speed space debris during over ten years of
operation, according to a photographic survey of the telescope鈥檚 exterior in
1999 (Orbital Debris Quarterly News online, vol 7, issue 1).
Collisions with millimetre-scale particles at speeds reaching 36,000
kilometres per hour have left centimetre-sized craters in Hubble鈥檚 exterior. But
none has caused significant damage, say NASA officials. In fact, the continued
peppering is a useful way of keeping tabs on orbital debris. Counting the
pockmarks is one of the few ways to gather data on the increasing amounts of
troublesome sub-millimetre-sized man-made debris that鈥檚 otherwise
undetectable.
