MSSL has three clean rooms for assembly, integration and test of flight instrumentation. The largest of these is an ISO Class 8 (Class 100,000) clean room with a high-bay area 10m x 10m x 7m high; and a low-bay area 12m x 15m x 3m high, shown below. The second room is ISO Class 6 (Class 1,000), 12m x 10m and contains most of the vacuum equipment; and the third is ISO Class 5 (Class 100), 15m x 8m, for precision assembly and optics work, also shown below.
