NASA: Last Wednesday (16), NASA announced that the Hubble Space Telescope had malfunctioned. The flaw in one of the computers, identified last Sunday (13), still remains unsolved as the agency works to resolve it.
On Friday night (18), an agency statement said the operations team has been running tests and gathering more information “about the system to further isolate the problem.” Meanwhile, the scientific instruments remain in a safe mode to avoid further problems.
On the other hand, the agency claims that both the telescope and its instruments are in good condition. Earlier in the week, NASA tried to restart the computer, but the attempt failed. Initially, the problem was suspected in a degraded memory module. However, after switching to a backup module, the problem persisted.
Midweek, the agency ran new tests with both modules “for more diagnostic information.” Unfortunately, the attempt was also unsuccessful.
Specifically, the agency reports that the payload computer is an NSSC-1 (NASA Standard Spacecraft Computer-1), built in the 1980s. The computer is responsible for controlling and coordinating scientific instruments, in addition to monitoring their health and safety.
NASA further details that there is a second computer in orbit to be used in case of a problem. Both can access and use “any of four independent memory modules, each with 64 kilobits of CMOS (Complementary Metal-Oxide Semiconductor) memory,” which she believes is redundancy.