Timeline for How did the Apollo guidance computers deal with radiation?
Current License: CC BY-SA 4.0
13 events
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| May 15, 2021 at 16:19 | history | edited | asdfex | CC BY-SA 4.0 |
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| May 15, 2021 at 16:19 | comment | added | asdfex | @fraxinus That is 'gate' as in 'logic gate', not as in 'gate of a FET'. | |
| May 15, 2021 at 14:36 | comment | added | John Doty | The other thing to note is that the AGC software was famously very robust against transient upset, although radiation was not a likely cause. | |
| May 15, 2021 at 13:47 | comment | added | asdfex | @DavidHammen Sure. You wrote "We didn't know how to do that in the 1960s" and I gave a counter example. | |
| May 15, 2021 at 13:09 | comment | added | fraxinus | Gate sizes? No one used field effect transistors in 1960s. Everything was bipolar. | |
| May 15, 2021 at 11:27 | comment | added | Foo Bar | Larger transistor gate size provides increased radiation hardness: doi.org/10.1016/j.microrel.2019.113457 | |
| May 15, 2021 at 10:55 | comment | added | David Hammen | @asdfex The question is about the Apollo Guidance Computer. The Saturn V did use triple redundancy in some places. But not the Apollo Guidance Computer. Unless you count the crew as independent computational devices, there was no triple redundancy. There was a separate computer system, the Abort Guidance System, whose services were never invoked. The AGS could only take over when one of those biological computational systems transferred digital control of the vehicle from the primary guidance system to the AGS. | |
| May 15, 2021 at 9:16 | history | edited | asdfex | CC BY-SA 4.0 |
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| May 15, 2021 at 8:55 | comment | added | asdfex | @DavidHammen That paper might be about fault tolerance in general, but fault tolerant computing as in triple redundancy, parity bits and error correction codes was known and used in the 60s. | |
| May 15, 2021 at 0:28 | comment | added | David Hammen | @OrganicMarble Leslie Lamport wrote about the Byzantine Generals Problem in 1982. That is the seminal paper on fault tolerant computing (cited ~7500 times). We didn't know how to do that in the 1960s. | |
| May 14, 2021 at 18:11 | comment | added | asdfex | @OrganicMarble Sources: My general knowledge of radiation effects, what I read about the AGC in the past years and the Wikipedia entry on the AGC... But I'd also like to see some real study about those old kinds of computers. | |
| May 14, 2021 at 18:05 | comment | added | Organic Marble | Some references would be nice! | |
| May 14, 2021 at 17:18 | history | answered | asdfex | CC BY-SA 4.0 |