The
Far Ultraviolet Spectroscopic Explorer (
FUSE) is a space-based
telescope operated by the
Johns Hopkins University Applied Physics Laboratory.
FUSE was launched on a
Delta II rocket on June 24, 1999, as a part of
NASA's
Origins program.
FUSE detected light in the far
ultraviolet portion of the electromagnetic spectrum, between 90.5-119.5
nanometres, which is mostly unobservable by other telescopes. Its primary mission was to characterize universal
deuterium in an effort to learn about the stellar processing times of deuterium left over from the
Big Bang.
FUSE resides in a
low Earth orbit, approximately 760 km (410
nmi) in altitude, with an inclination of 25 degrees and just less than a 100-minute orbital period. Its
Explorer designation is
Explorer 77.