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"From the dawn of the Space Age through the present, NASA has relied on resilient software running on redundant hardware to make up for physical defects, wear a
by somat 7mo ago
"From the dawn of the Space Age through the present, NASA has relied on resilient software running on redundant hardware to make up for physical defects, wear and tear, sudden failures, or even the effects of cosmic rays on equipment."
An interesting case study in this domain is to compare the Saturn V Launch Vehicle Digital Computer with the Apollo Guidance Computer
Now the LVDC, that was a real flight computer, triply redundant, every stage in the processing pipeline had to be vote confirmed, the works.
https://en.wikipedia.org/wiki/Launch_Vehicle_Digital_Computer https://en.wikipedia.org/wiki/Launch_Vehicle_Digital_Compute...
Compare the AGC, with no redundancy. a toy by comparison. But the AGC was much faster and lighter so they just shipped two of them(three if you count the one in the lunar module) and made sure it was really good at restarting fast.
There is a lesson to be learned here but I am not sure what it is. Worse is better? Can not fail vs fail gracefully?
- baud147258 7mo ago> Worse is better? Maybe if you know what the tradeoffs are and are ready to deal with the deficiencies (by rebooting fast). And didn't they had issues with the lunar module Guidance Computer on the first moon landing?
- throwup238 7mo ago> There is a lesson to be learned here but I am not sure what it is. Restart your Claude Code sessions as often as possible
- KurSix 7mo agoI think the lesson is that redundancy can exist at different layers
- budman1 7mo agoIt all depends on the failure. A transient bit failure in digital circuits? Then reboot and away you go. A coding / algorithmic defect. Reboot and you are back in the same place. Also, the AGC was directly interfaced to an astronaut. They could decide to ignore erroneous outputs from the AGC.
- anonymous_user9 7mo agoThe command module and lunar module each had one AGC. (The lunar module did include a simpler backup computer called the Abort Guidance System.) I think this is because an AGC failure is recoverable in most phases of flight, while an LVDC failure is not.