Surprise. Fortran was used as well but Forth was used quite a bit by NASA. In some ways it is extremely auditable. A handful of assembler functions sit at the bottom the rest is Forth. Minimal numbers of variables in memory if code is written to use the data stack for inputs and outputs to functions. Much easier to certify than GCC. :-)
There were a number of Shuttle experiments where the control software was written in Forth. It gives you a control interpreter out of the box and also bit level access to hardware so you can write custom drivers and then script the hardware control in the functions you wrote or compile them where speed is required, using an 8K..12K kernel.
The Cassini probe used Forth software running on a Forth 2-stack CPU.
There were a number of Shuttle experiments where the control software was written in Forth. It gives you a control interpreter out of the box and also bit level access to hardware so you can write custom drivers and then script the hardware control in the functions you wrote or compile them where speed is required, using an 8K..12K kernel.
The Cassini probe used Forth software running on a Forth 2-stack CPU.