Cosmic Origins Spectrograph inspection. Clean room worker inspecting the Cosmic Origins Spectrograph (COS) instrument under ultraviolet light. Also known as black light inspection, this process uses ultraviolet (UV-A) fluorescence to detect possible contamination or defects in the device. The COS, an ultraviolet spectroscope, was installed on the Hubble Space Telescope in May 2009. Its increased sensitivity is being used to probe the large-scale structure of the universe, including the gravity of dark matter and the form of galaxies and intergalactic gas. Photographed in the Payload Hazardous Processing Facility at the Kennedy Space Center, Cape Canaveral, Florida, USA.