Launched in June 1999 and originally designed for a three-year mission, NASA's Far Ultraviolet Spectroscopic Explorer astronomy satellite is back in full operation. The FUSE satellite is working again thanks to a team of scientists and engineers at the operations centre in Johns Hopkins University who reprogrammed its onboard software control system during 2005 to continue the mission. FUSE had a near-death experience in December 2004 when the third of four onboard reaction wheels stopped spinning, depriving the satellite of stability and fine-pointing capacity.
"This return to operation is great news," declared Jean Dupuis, astronomer at the Canadian Space Agency. " With its high sensitivity and great powers of resolution, FUSE will keep providing Canadian and foreign astronomers with very interesting research opportunities."
FUSE now operates using onboard magnetometers for slewing, and uses its Canadian-built Fine Error Sensor cameras to measure drift rates after slews. Such functions were never intended for these components in the original design. In January 2006, FUSE operations were returned to efficiency levels seen early in the mission. Now the satellite will continue a broad range of science programs for hundreds of astronomers from around the world. To date, more than 350 publications based on FUSE observations have been published in the professional astronomy literature and many more are on the way. Canadian scientists have authored 74 of these publications.
FUSE is an orbiting telescope jointly run by NASA, the Canadian Space Agency, and the Centre national d'études spatiales, in Toulouse, France. Canada contributed the Fine Error Sensor camera system for tracking the telescope; it was built by COM DEV with technical advice and design work from the Herzberg Institute of Astrophysics in Victoria, B.C. FUSE partners also include Honeywell Technical Services Inc., the Johns Hopkins Applied Physics Laboratory, the University of Colorado at Boulder, the University of California, Berkeley, and the Orbital Sciences Corporation. France supplied the unique spectroscopic gratings.
Observations from the satellite have been used to discover an extended, tenuous halo of very hot gas surrounding our Milky Way galaxy, and evidence of similar hot gas haloes around other galaxies has been found. FUSE has also detected molecular hydrogen in the atmosphere of the planet Mars for the first time. This has implications for the water history of our frozen neighbour. In addition, FUSE observations first detected molecular nitrogen in dense interstellar gas and dust clouds, but at levels well below what astronomers had expected, requiring a return to the drawing board for theories of interstellar chemistry.
For more information
Canadian Space Agency
Tel.: (450) 926-4370