SpaceX: Lessons Learned Developing Software For Space Vehicles
jrepin writes "On day two of the 2013 Embedded Linux Conference, Robert Rose of SpaceX spoke about the 'Lessons Learned Developing Software for Space Vehicles.' In his talk, he discussed how SpaceX develops its Linux-based software for a wide variety of tasks needed to put spacecraft into orbit—and eventually beyond. Linux runs everywhere at SpaceX, he said, on everything from desktops to spacecraft."
I started my career in nuclear engineering before moving into software development.
There were three really important principles: Redundancy (having several of everything); Diversity (having different implementations i.e. different designs from different manufacturers) and Segregation (keeping things physically separate and firewalled off from each other).
I'm a bigger Linux fan than many here. I've been using it since 1995 and I'm a die-hard Slackware user, but having everything running on the same OS seems like an accident waiting to happen. Yes, I know that it's great that you can have one piece of code that you can compile and run anywhere, and that's easier if you're only using one OS.
However, one of the great things about Open Standards and Open Source was (is) that for many years software was portable so that it could be compiled and run on big- or little-endian 32- and 64-bit POSIX-like systems on a wide variety of CPU architectures.
That may have been "expensive" in terms of software maintenance, but as I learned when working for a now-defunct very large UNIX company, writing your software to be portable across those systems exposes (and forces you to fix) many subtle bugs that otherwise would not have been found until deployment.
Also, relying on just one OS puts you at the mercy of any latent bug in that specific system. Having a diversity of OSes in use mitigates that problem.
The state of Software Engineering in general is still pretty primitive. I'm still amazed at the poor quality of a lot of "professional" code and the cavalier attitude towards testing...In the land of the blind, the one-eyed man is king.