[_Jim]

Are there hashes or keys that must be verified before being executed by the on-board computers?

There is a LUG (Linux User Group) of about 25 people who were doing some open-source work for them on flight control software - it looks like maybe there was a version control snafu or something (like perhaps an Alpha or Beta release) got mixed in with the production code ...

[Resolute]

This is the first time I have read mentioned of "open source" contribution to space shuttle flight software, in this context. If I understand your assertion, some untested and / or faulty code could have become part of the flight build. Yikes. Have you any more details at this time? (Such as links?) Thanks.

[StopGlobalWhining]

There is a LUG (Linux User Group) of about 25 people who were doing some open-source work for them on flight control software -...

One thing we do know for sure though is that at least we can rest assured that no Microsoft code was involved in the Shuttle flight control system. That in itself eliminates one of the biggest uncertainties in the integrity of the code.