Electrical Problems on the Shuttle

[Tuckerfan]

This doesn’t look good at all.

“Without new evaluation technology, the inability to detect unseen wiring problems will continue to be a safety risk for the orbiter and any next-generation space vehicles,” the NASA Office of Inspector General said in a summary of the agency’s response to accident board recommendations.

A July 1999 shuttle launch illustrates the kind of disaster that could be triggered by faulty wiring.

With five astronauts aboard Columbia, an electrical short knocked out two main engine computers five seconds after launch, leaving the crew one failure away from a risky and unprecedented emergency-landing attempt.

Investigators later determined that a frayed Kapton wire “arced,” sending an electrical current from an exposed conductor to a nearby metal screw head, triggering the short and the resulting failure of the engine computers.

Currently, NASA and contractor engineers visually inspect wiring they can see. But some wires – such as those located beneath the crew cabin – are inaccessible. About 1,700 feet of Kapton wiring cannot be reached.

For some reason, I’m reminded of Apollo 1.

The Apollo program was put on hold while an exhaustive investigation was made of the accident. It was concluded that the most likely cause was a spark from a short circuit in a bundle of wires that ran to the left and just in front of Grissom’s seat. The large amount of flammable material in the cabin in the oxygen environment allowed the fire to start and spread quickly.