Re:Shouldn't that be too bloated to test? (Score 2, Informative)

Besides which, once the flight control system version x.y is finished, the development tea doesn't then immediately start working on flight control system version x.y+1 (or worse, versionn x+1.0). It isn't as if NASA finishes a shutttle, and then immediately starts building a new, improved shuttle.

Every flight requires a new version of the primary flight control software and, because of the long lead time to prepare a version, they often have 2 or more in the works at the same time. At one time in 1983 there were 5 versions being worked on simultaniously.

Reliability in the flight control software for the space shuttle comes at a price. Their cost per line of code is $350*. That buys more quality than most commercial vendors can afford.

Eddie Burris

*http://www.stsc.hill.af.mil/crosstalk/1998/11/k rasner.asp/