Flawed Drawings Caused Spacecraft Crash

Investigators may have discovered what caused the Genesis spacecraft to crash into the Utah desert this September. Some crucial switches were installed backwards, because of an error in the instructions.

The problem stems from the craft's design drawings, made by Lockheed Martin in 2001. They showed that some tiny cylindrical plungers, designed to detect the gravity of an incoming planet and deploy a parachute, were installed the wrong way.

There were four such switches - two as a backup in case the first two failed. But all of them had been installed backwards. As a result the parachute didn't open, and the capsule plummeted to Earth.

Redundancy doesn't work too well if your redundant system is the same as your primary system, and thus liable to the same flaws or mistakes.

None of NASA's review processes picked up the mistake. "It would be very easy to mix this up," says Michael Ryschkewitsch, chair of NASA's mishap investigation board at the Goddard Space Flight Center in Greenbelt, Maryland.

But of course, the blame rests entirely with Lockheed Martin, just as it did with the metric conversion error, right?

On the bright side, the error doesn't seem to have been repeated on Stardust:

The Stardust sample return mission, which is set to return to Utah in 2006 carrying a portion of a comet's tail, has the same switches as Genesis. Fortunately, that craft's designs show that they were installed correctly.

Posted by T.L. James on October 18, 2004 08:47 PM