Apollo Guidance Computer History Project

Second conference

September 14, 2001

Role of the Personal Background

FRED MARTIN: I want to say that, from the background of people, it's interesting. In those days, we of course had physicists on the job and mathematicians and engineering graduates and students. We probably had a literature major here and there, too, who jumped in there. There was no computer science discipline as such. There was nobody there who was a computer scientist per se. I don't think they even taught it.

MARGARET HAMILTON: It was not taught as a course back then.

FRED MARTIN: But I often felt that part of our success at that time was due to the engineering and physical science backgrounds of a lot of those people. Maybe they weren't the most elegant programmers but they understood what the specific impulse of an engine was and the physics of what you were trying to do. You weren't taking somebody from the inside of a computer and trying to get them to understand the problem that you were trying to solve. I'm not saying they couldn't do that. But I'm just saying that, at that time, I thought that one of the reasons that we  were rapidly able to do this was that there was a great understanding of what the problem was. Even if we had to do some fast learning, people had the basic tools.

Hugh Blair Smith adds:

I think the mixture of personal backgrounds was also significant. Bill Widnall was one of the most brilliant analysts of physical systems you can imagine, yet I was able to help him with a programming problem because of my background in making mathematics-oriented code fit into tight places. One evening I found him muttering over some matrix calculations that were taking so long as to present a problem in real-time processing. He showed me what he was doing--I think they were 6x6 matrices--and I saw that the straightforward algebraic approach involved a number of operations proportional to the fourth power of 6. By combining terms differently, the number became proportional to the third power, and the performance problem disappeared. Just another example of how everybody was willing to help everybody else, and willing to listen!

ALEX KOSMALA: I remember when you joined, Margaret. One of the first things I did in interfacing with you was to explain inertial navigation system to you. And you were a math major, if I remember rightly. You understood but you hadn't worked with coordinate systems. I spent a couple of hours, a couple of days, going through what the basis of the guidance system was and how it worked and blah, blah, blah. I never talked to you about that again. Because you understood. And you became at least somebody who knew something about inertial navigation systems, how you describe them and how you control them.

Computer simulations

site last updated 12-08-2002 by Alexander Brown