spacetoday.net: Faulty connector blamed for shuttle sensor glitches

Posted: Wed, Dec 19, 2007, 7:30 AM ET (1230 GMT)
STS-122: Shuttle on pad before launch (NASA/KSC)

A tanking test of the space shuttle on Tuesday allowed engineers to identify the cause of faulty sensor readings that scrubbed two shuttle launch attempts earlier this month. The tanking test, conducted after shuttle workers added additional instrumentation to the shuttle's external tank, revealed that electrical connectors that carry data through the wall of the external tank were at fault, and not the sensors themselves. The engine cutoff sensors, designed to determine when the shuttle's liquid hydrogen fuel is exhausted, generated erroneous data during tests in the hours leading up to launch attempts on December 6 and 9. Tuesday's tests revealed that the sensors were not at the fault, and the connectors can be accessed while the shuttle remains on the launch pad. Shuttle officials said, however, they were not sure any repair work could be completed in advance of the currently-planned January 10 launch.