Posted by speckx 1 day ago
Basically, yes, radiation does cause bit flips, more often than you might expect (but still a rare event in the grand scheme of things, but enough to matter).
And radiation in space is much “worse” (in quotes because that word is glossing over a huge number of different problems, both just intensity).
That was in the 2000s though, and for embedded memory above 65nm.
And obviously on earth.
CPUs: IBM PowerPC 750FX (Single-core, 900 MHz, 32-bit, radiation hardened)
RAM: 256 MB (per processor)
OS: VxWorks (Real-time OS)
Network: TTEthernet (Time-Triggered Ethernet) at 1 Gbps
programming: MISRA C++, flight control laws from Simulink adn MATLAB.> It’s a complex machine. There’s three computers all talking to each other for a start, and they have to agree on everything.
Primary, Real-Time Secondary and Third for regulating votes.
It would be really cool to see a visualization of redundancy measures/utilization over the course of the trip to get a more tangible feel for its importance. I'm hoping a bunch of interesting data is made public after this mission!
I would expect to see multi-party-signed deterministic builds etc. Anyone have any insight here?
I would -hope- NASA does not trust their OS supply chains to a single person for high risk applications, but given even major companies I audit do this with billions of dollars on the line, it would not shock me if NASA has the same stance which worries me a bit.
They would need to be using something like heavily customized buildroot or stagex to produce deterministic OS images.