A NASA building in which instruments and software are integrated in a spacecraft and tested. This is done at the Jet Propulsion Laboratory in Building 179 which has two clean rooms. The leading facility for creating robotic Solar Systemexplorers, SAF has assembled and tested 19 spacecraft, including Galileo, the Hubble Space Telescope, the Voyager and Viking probes, Cassini–Huygens, the Spitzer Space Telescope, and more.