[Beowulf] Why We Need a Supercomputer on the Moon

Lux, Jim (337C) james.p.lux at jpl.nasa.gov
Tue Oct 16 10:04:04 PDT 2012



Jim Lux
> Not as bad as all that.  I've actually been looking for an actual 
> documented instance of a commercial non-space part failing in space.
> There's quite a few flying, but nobody has been able to point to a 
> specific case.

I see. But, do you know how far away from Earth those parts were traveling? I understand that the farther they will go, the worse they will fare (a rather simplistic way to say it, since this is probably more complicated).

> Once you get above LEO, it's all pretty much the same.  Your big issue is CMEs and Galactic Cosmic Rays, and they're everywhere.  Well, if you're a bold sort and heading to, say, Io or Europa, you can count on megarad kind of doses.. As they say.. the auroral displays on Io are probably pretty cool looking, until you die of radiation exposure.




Atmosphere and magnetosphere give us (and our computers) quite good protection. But on Moon's orbit, no more. For one example, there was solar storm between Apollo 16 returned home and 17 started. But it seems astronauts would easily survive if they stayed inside, from what they write here:

http://science.nasa.gov/science-news/science-at-nasa/2005/27jan_solarflares/

So, I take it the people are going to be safe. Do you think computers would be safe, too? I mean off the shelf equipment.


> I understand that Apollo "got lucky" in terms of radiation exposure of astronauts.  Only a week in space (I think that "could have saved life" for a 400 rem dose is being pretty optimistic. LD50 is around 5 Gray (500 rem) with *prompt* medical assistance, which doesn't do you much good when it takes 3 days to get home, best case).  Yes, the moon would shield you if you are on the dark side, but unfortunately, the moon does rotate, so you get 2 weeks of shielding, then 2 weeks of exposure, etc.    I don't know that ISS is all that shielded:  maybe a few cm of Aluminum in some directions, but it also has windows, and scattering is a real issue. And when you're looking at 100 MeV protons, they zip right through 1 cm of Aluminum.  

> As far as equipment.. they do tests all the time on commercial gear going to ISS (and on shuttle). 
https://nepp.nasa.gov/files/18365/Proton_RHAGuide_NASAAug09.pdf
https://escies.org/download/webDocumentFile?id=305
http://klabs.org/richcontent/eeelinks/EEE_Links_Index.htm
http://klabs.org/papers.htm



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