A NASA ultraviolet astronomy satellite, launched in 1999 June. It performed high-resolution spectroscopy in the wavelength range 90–120 nm using four mirrors each 0.39 by 0.35 m. It was many thousands of times more sensitive than the Copernicus satellite, the only previous mission to cover this region. Observations ceased in 2007 July.

http://archive.stsci.edu/fuse/ Official mission website.