In aerospace you’re often dealing with low-level hardware integration, and tight control of timing is usually pretty important. So you’re quite often working on embedded systems (usually C/C++) and real-time operating systems. To get the hardware components working together in a tightly integrated fashion you need to be directly interfacing with I/O pins… for example, using bit-banging to build a software driver for a new hardware component (like a custom radio) that needs to be controlled directly from the CPU. Aside from practical experience with embedded processors and the debugging tools like oscilloscopes, you need at least some background in electrical engineering to understand the circuit designs.


Some of the higher level systems in a satellite or rocket run a unix operating system with a full TCP/IP stack and higher-level languages like Java. On bigger vehicles I’ve seen the communications pipeline to a ground station (telemetry about the performance of the vehicle, video feeds, etc.) built on Linux+Java. For these kinds of higher-level systems, the skill base is software engineering more akin to internet web development. Except that you have to assume near-constant network outages and packet loss, and bandwidth will be severely limited! So you have to use the appropriate messaging protocols to overcome those kinds of constraints.