NASA’s latest Mars rover has the same processor as an iMac from 1998
theverge.com
theverge.com
There's the complexity problem, but inherently is a space device heading to a single CPU execution model? I would have expected some variant of TMR for rad error detection and sw update methods which only do one at a time. TMR is standard in flight control logic.
And, what's the emergency backup cpu? The one which halts, points a radio antenna at a fixed point known to intersect the earth in some cycle time including months, and sits at the bootloader waiting for an instruction stream...
> Mars’ atmosphere offers far less protection from harmful radiation and charged particles than Earth’s atmosphere. A bad burst of radiation can badly wreck the sensitive electronics of a modern processor — and the more complex the chip, the more can go wrong. Plus, at 138 million miles away, it’s not like NASA can just swap out the processor if things go sideways.
> To make the system even more durable, the PowerPC 750 chip in Perseverance is a little different than the one in the old iMacs. It’s technically a RAD750 chip, a special variant that’s hardened against radiation and costs upwards of $200,000