[rbanffy]

I agree with you - the hardware and its configuration is very different between all of them. Yet, the basics are the same and a lot of code could be shared between the different spacecraft if they builders agreed on a certain level of commonality (and it doesn't even need to be a high one).

And yes - a common OS for spacecraft would be a giant leap forward, abstracting the differences in hardware and providing a unified interface for everyone using them.

The strongest barrier against sharing development is the security concerns. Nobody wants people to build missiles with that.

http://www.openpilot.org/ has, so far, avoided these problems.