A sanitized interior area used by NASA to prepare a spacecraft for launch. This is where the engineering components and instruments of the spacecraft are put together and tested by computer programs. The Cassini spacecraft, for instance, was taken to a 21 × 21-m/70 × 70-ft ‘high bay’ that was certified as a class 100 000 clean room. In such a clean room, the air is filtered so that there is less than one particle of dust bigger than 1 micron per 100 000 cu ft (2832 cu m) of air. Astromaterials such as Moon rocks and meteorites are handled and studied in clean-room laboratories to prevent terrestrial contamination. The Lunar Sample Laboratory, for example, is a class 10 000 clean room and the recently constructed Genesis Laboratory is a class 10 clean room.