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LIVE: Launching astronauts from US soil to ISS for first time in last 9 years
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Mr. Scram:

--- Quote from: IDEngineer on June 01, 2020, 07:14:00 am ---Found today that SpaceX writes their code in C++, their screens in JavaScript, the OS is Linux, and the platform is PowerPC. They do not use rad-hard components but instead shield at the modular level.

--- End quote ---
They also use ridiculous amounts of redundancy. Almost every CPU is tripled and the set uses majority voting. There are many, many CPUs aboard for all kinds of subsystems.
IDEngineer:

--- Quote from: Mr. Scram on June 01, 2020, 10:23:53 pm ---They also use ridiculous amounts of redundancy. Almost every CPU is tripled and the set uses majority voting.
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That's very common. Even the Shuttle had such redundancy. IIRC, it had five computers, three of which were "live" at any one time, with one auto-backup and I can't remember when the fifth came into play. On the original launch in 1980(?) one shut down and a backup kicked in. Then a SECOND one shut down. I remember John Young saying his knees got a little weak at that point. But it all turned out fine... it wasn't CPU's that cost us two Shuttles and two groups of astronauts.
0culus:

--- Quote from: IDEngineer on June 02, 2020, 06:56:23 pm ---
--- Quote from: Mr. Scram on June 01, 2020, 10:23:53 pm ---They also use ridiculous amounts of redundancy. Almost every CPU is tripled and the set uses majority voting.
--- End quote ---
That's very common. Even the Shuttle had such redundancy. IIRC, it had five computers, three of which were "live" at any one time, with one auto-backup and I can't remember when the fifth came into play. On the original launch in 1980(?) one shut down and a backup kicked in. Then a SECOND one shut down. I remember John Young saying his knees got a little weak at that point. But it all turned out fine... it wasn't CPU's that cost us two Shuttles and two groups of astronauts.

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IIRC the final computer ran software independently developed from the primary ones.

https://history.nasa.gov/computers/Ch4-3.html
IDEngineer:

--- Quote from: 0culus on June 02, 2020, 07:01:32 pm ---IIRC the final computer ran software independently developed from the primary ones.
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That's what I thought I remembered, but wasn't sure so I didn't want to say so.

I'd be tempted to specify things at the MODULAR level and have separately developed hardware too, but rad-hard stuff isn't exactly commonplace. SpaceX's approach of hardening the enclosure is the better solution IMO because it affords such flexibility.
dr.diesel:
During the Starlink launch last night the host mentioned the SpaceX Software Team will be hosing a Q&A on Reddit in the next couple weeks.  Might be a great opportunity for further info on OS/Touchscreens etc.
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