Columbia, other shuttles have history of computer glitches

Computerworld - WASHINGTON -- Columbia and other space shuttles have a history of computer glitches that have been linked to control systems, including left-wing steering controls, but NASA officials say it is too early to determine whether those glitches could have played any role in Saturday's shuttle disaster.
While suspicions about the cause of the crash of Columbia center on the spacecraft's left wing and the possibility that it could have been damaged during launch, a NASA spokesperson said it is too early in the investigation to determine if a malfunction in any of the space shuttle's five redundant control computers contributed to the craft's breakup.
William Readdy, deputy administrator of NASA, said officials are actively searching for any of the shuttle's five onboard computer systems. Although it's unlikely that they survived the crash, Readdy said, the computers have "memory resident in them" that could shed light on the status of the shuttle after communications were lost with ground control.
Each computer's memory stores "telemetry of thousands of parameters that affect the flight of the shuttle," he said.
Columbia and other space shuttles have experienced a series of control computer failures during the past two decades, including one that had a direct link to the spacecraft's left-wing control systems.
During a March 1996 return flight, NASA officials discovered a computer circuit problem that controlled steering hardware on Columbia's left wing. The computer circuit was responsible for controlling the spacecraft's left rudder, flaps and other critical landing functions.
Speaking at a news conference prior to Columbia's landing in 1996, NASA spokesman Rob Navius downplayed the seriousness of the computer problem. "There are three additional paths of data that are up and running in perfect shape, and there's multiple redundancy that would permit a safe landing," he said. Although Columbia landed without incident that time, NASA officials said in news accounts at the time that the failure was significant enough that, had it happened earlier in the flight, the agency would likely have ordered the shuttle home early.
NASA was also forced in 1983 to delay a landing by Columbia for several hours because of the failure of two onboard control computers. According to an Air Force study of early space shuttle flights, the problem was significant. After the two general-purpose computers failed, "only one of the two computers could be reinitiated," according to the Air Force study, "The Cape: Military Space Operations 1971 - 1992."
In fact, the failure of Columbia's computers was serious enough to force the flight director to wave off