First computer on the moon

Here’s a really fascinating piece on the BBC about NASA programmer Don Eyles and the team behind the storied AGC (Apollo Guidance Computer). Don was only 23 when he got the gig. Maybe it was good that he was young and naive. As he says: “I don’t recall the risk and the responsibility and the fact that other people’s lives were to some extent in our hands.”

There are few instances in which I’m happy to be as old as I am. The fact that I got to live through and be an active observer (aka space geek!) during the Apollo program is one of those times. I still get chills reliving some of that footage.

There’s a great jargon term in here, too: “LOL memory.” It stands for “Little Old Lady memory” and refers to the “rope core memory” used in the AGC that required teams of (women) employees to weave meters and meters of copper wire around magnetic cores.

Weaving the way to the Moon [Thanks, Brian Jepson and Mike Loukides!]

7 Responses to First computer on the moon

svofski on July 16th, 2009 at 11:57 am said:

I’m not a native speaker and it bugs me every time when I see this. Isn’t the AGC famous, as in being valuable, of great service and memorable and not “infamous” or “notorious”, as in buggy and killing people?

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AndyL on July 16th, 2009 at 4:58 pm said:

Perhaps “infamous” refers to the way it failed during landing and required Armstrong to take over manual control.

Or am I thinking about a different computer?

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- Brian McNett on July 16th, 2009 at 5:32 pm said:
  
  The AGC performed flawlessly. The 1201 and 1202 alarms were due to the fact that Armstrong and Aldrin had unnecessarily left the rendezvous radar on, overloading the computer’s input buffer. The landing was supposed to be done with the radar off (it was useless in a landing situation anyway).
  
  Of course the reason for leaving the radar on, was that there was no assurance that they wouldn’t have to quickly abort and return to orbit.
  
  Complexities like this are often overlooked. Later missions left the radar off. NASA continued to use the AGC without modification for the rest of the program.
  
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- svofski on July 16th, 2009 at 5:35 pm said:
  
  Thanks. The failure wasn’t mentioned in this video and article text and I didn’t know about it at all, so this wasn’t obvious to me. It must be some universal knowledge then?
  
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Gareth Branwyn on July 16th, 2009 at 8:18 pm said:

@svofski
You’re right. There has been a meaning drift on that word, and while I agree with the idea that, in language, people ultimately vote with their usage, “infamous” is not what I meant here, even in its weaker form. I was referring to the many stories of the absurd lengths that were gone to in creating the AGC (like the hand-woven “rope core memory”), the nervousness around this system, using new technologies like ICs, and of course, the minuscule processing power and memory involved. Maybe “storied” is the right adjective.

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Anonymous on July 16th, 2009 at 9:24 pm said:

TALES FROM THE LUNAR MODULE GUIDANCE COMPUTER

http://www.doneyles.com/LM/Tales.html

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Ben on July 19th, 2009 at 2:06 pm said:

Why bother ?
They did not step on the moon

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