John Shannon, shuttle program manager at the Johnson Space Center in Houston, said the flight will likely be rescheduled for next February or April, giving NASA time to prepare a replacement computer for delivery.
NASA scientists announced last week that a data formatter and control unit had "totally failed" on Sept. 27. The Science Data Formatter is designed to take information from five onboard instruments, format it into packets, put a header on it and send it to Earth at speeds of up to 1Mbit/sec.
Michael Moore, a program executive for the Hubble Space Telescope, said that the problematic computer has been online since the telescope was put into orbit by the space shuttle Discovery in 1990. The computer was designed by IBM in the 1970s and built by the former Fairchild Camera and Instrument Corp. in the 1980s.
Moore said the computer is a relatively simple machine but is a key part of the observatory's communications system. He added that the malfunction is the first to require that a replacement machine be delivered to the telescope.
NASA scientists are now readying onboard redundant systems to take on the communications tasks. The replacement system will be the new redundant system.
Preston Burch, Hubble manager at NASA's Goddard Space Flight Center in Greenbelt, Md., said that the exact cause of the problem won't be determined until the disabled computer is returned to Earth. "It may be thermally related," he said, noting that the "unit does run at a relatively high temperature, and high temperatures tend to accelerate any kind of degradation process."
According to Moore, remotely switching over to the redundant systems should take about 10 hours. Technicians and scientists expect to do it late next week, he added.
Ed Weiler, associate administrator of NASA's Science Mission Directorate, noted that the switch-over and subsequent installation of new redundant systems should add another five to 10 years to the telescope's life.
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