It was obsoleted but we could get enough stock for the project. What we didn’t realize at the start was that the previous project had lower standards for development and testing and didn’t have the special debugger or great code. The debugger had to be special ordered for a ton of money and no vendors wanted to work on it.
Had a chance to revision up and changed to a pretty obscure atmega micro that was a perfect replacement. Did radiation screening again, development and testing..
That part was obsoleted too and I can’t use it for my next project. Will probably buy a space grade cpu for $20k this time. Radiation screening alone for a few components is $50k.
I've never sent any hardware into space, but some former colleagues of mine were working on OWL around the time I left: https://asd.gsfc.nasa.gov/archive/owl/science.html
I have a good friend however who is a great writer, and who has written a lot about her experiences, and who is working there again: https://www.jamiezvirzdin.com/
She didn't work much on the software/hardware side of things, however.
Maybe one day I'll sit down and put some of it to paper, I definitely have a lot of stories to tell.
It was extremely expensive, and commercial, I'm honestly surprised I could even find a website for it.
It was extremely cool to basically scroll through memory, our hardware had an on-board FPGA that gathered waveforms from a photomultiplier tube attached to a scintillator, and when I was writing the driver for it, I could watch the memory in real-time with the debugger changing.
Setting initial values of memory to something like 0xDEADBEEF, and using this thing, was an incredibly powerful debugging strategy, especially when dealing with hardware.
I cut my embedded development teeth writing device drivers and custom firmware targeting it.
The reason we used SH4 is because the Dreamcast had failed, so there was a huge surplus of them available on the market at the time.
It was easily one of the most interesting and rewarding projects of my life to work on.