* The Rosetta probe ultimately runs SCL (Spacecraft Command Language) [1], a COTS spacecraft programming language developed for sale to the military [2]; SCL is based on the syntax of Ada 83, which has a long legacy in spaceflight and other real-time applications (e.g. Boeing 777) [3]. However, what are known as Flight Control Procedures (uploaded commands), are written using another language and transformed and compiled into SCL in a two-step process that involves XSLT [1]. On-board Control Procedures, which are procedures the probe decides on its own to run, and handle tasks such as receiving FCPs and sending back telemetry, are written in SCL [1].
* The Mars rover Curiosity is programmed in C and uses the VxWorks RTOS [4], which is very much like many commercial embedded systems. It has about 2.5 million lines of code, much of it autogenerated. Curiosity's predecessors, Spirit and Opportunity, used the same software stack, as did their predecessor, Sojourner [8].
* The Voyager probe, which has now left the solar system and entered interstellar space, uses "...interrupt driven computer[s], similar to processors used in general purpose computers with a few special instructions for increased efficiency. The programming is a form of assembly language." [5]
* The Space Shuttle was programmed in a custom language called HAL/S (High-order Assembly Language/Shuttle) [6], as was the Jupiter probe Galileo [7]. The language is descended from PL/I and its compiler is written in a subset of PL/I called XPL.
[1]: http://www.rheagroup.com/wp-content/uploads/2014/01/SpaceOps...
[3]: https://en.wikipedia.org/wiki/Ada_(programming_language)
[4]: http://programmers.stackexchange.com/a/159638
[5]: http://voyager.jpl.nasa.gov/faq.html
[6]: https://en.wikipedia.org/wiki/HAL/S