All ten instruments aboard the Upper Atmosphere Research Satellite (UARS) were brought back to full operation July 21, according to NASA. Problems with the drives for the satellite's solar array led flight controllers to shut down the satellite's instruments on July 2 (see Eos, June 16, 1992).
Subsequent tests showed that the main drive, now in use again, has a damaged but usable clutch, according to John Donley, UARS deputy project manager. The back-up drive, however, cannot be used safely. “We've lost our basic redundancy,” he said