The Mars Curiosity rover has landed successfully, and one of the promo videos "7 minutes of terror" brags about there being 500,000 lines of code. It's a complicated problem, no doubt. But that is a lot of code, surely there was a pretty big programming effort behind it. Does anyone know anything about this project? I can only imagine it's some kind of embedded C.
It's running 2.5 million lines of C on a RAD750 processor manufactured by BAE. The JPL has a bit more information but I do suspect many of the details are not publicized. It does appear that the testing scripts were written in Python. 

The underlying operating system is Wind River's VxWorks RTOS. The RTOS in question can be programmed in C, C++, Ada or Java. However, only C and C++ are standard to the OS, Ada and Java are supported by extensions. Wind River supplies a tremendous amount of detail as to the hows and whys of VxWorks.

The underlying chipset is almost absurdly robust. Its specs may not seem like much at first but it is allowed to have one and only one "bluescreen" every 15 years. Bear in mind, this is under bombardment from radiation that would kill a human many times over. In space, robustness wins out over speed. Of course, robustness like that comes at a cost. In this case, it's a cool $200,000 to $500,000.

An Erlang programmer talks about the features of the computers and codebase on Curiosity.
