Posted: Fri, Dec 14, 2001, 8:05 PM ET (0105 GMT)
NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) spacecraft entered safe mode earlier this week because of a reaction wheel problem, project officials said Friday. On December 10 the second of four reaction wheels on FUSE stopped spinning, triggering a safe mode condition where the spacecraft stops scientific operations and orients its solar panels towards the Sun. The first reaction wheel shut down last month. Engineers have been unable to spin up the wheels, and are looking at an alternative method for attitude control using magnetic torquer bars on the spacecraft. Engineers and managers at NASA, Johns Hopkins University, and Orbital Sciences Corporation are looking into this alternative but did not mention when they believe when the spacecraft's attitude control will be restored. FUSE was launched in June of 1999 on a three-year mission to study the universe at far ultraviolet wavelengths.
