Now reading: Digital Apollo

David Mindell, Digital Apollo: Human and Machine in Spaceflight (2008). (Goodreads/review - notes)


I found this book while searching for more information about the Apollo Guidance Computer in preparation for a talk (see: Landing on the moon: three visions attained). Fortunately for me, the nearest St. Louis County Library branch to work had a copy.

I had assumed the book was just about the computer itself, which was why I got it, but at ~80 pages in, it really hasn't been covered except by reference. Instead, what the book has covered is something that I recognize from developing flight controls back at Mason, and to some extent in systems engineering in my current position: the tension between the human pilot and the automatic pilot (and by extension its designers). It's an inevitable tension—in simplistic ego terms, the fight between controlling and being controlled. In more sympathetic terms: it takes more than equations to design and more than human experience to fly a sufficiently complex aircraft.

So: straight ahead, learning more about X-15, etc., until I get to the parts about the AGC and flight software that I wanted to learn more about. In the meantime, the book has also been the source of some interesting citations:

[p. 73] In those days, airplanes were unreliable and I thought they might become more so. I never flew without a pair of pliers, a screwdriver, and a crescent wrench in pocket so I could fix things on the airplane. This was being a mechanic, not an engineer. I had applied for the Engineering School because I thought there should be a better rapport between the aeronautical engineer and the pilot. It seemed to me that the engineers felt pilots were all a little crazy or else they wouldn't be pilots. The pilots felt the engineers as a group were, if not incompetent, at least not thoroughly acquainted with the pilot's viewpoint—that all the engineers did was zip slide rules back and forth and come out with erroneous results and bad aircraft. I thought from a philosophical point of view that it would be good to have engineers and pilots understand one another better. It seemed desirable to marry these two capabilities in one person—and I wanted to be that person.

—General Jimmy Doolittle, I Could Never Be So Lucky Again: An Autobiography (1991)

To train the pilots for the X-15 landing phase, several methods were considered. First, an analog computer was used with an oscilloscope presentation to indicate approach attitude. This gave the pilots and engineers an understanding of the relative importance of the factors affecting the landing flare, but definitely lacked the in-flight realism afforded by the rapid approach of the ground.

—Dick Day, Training Considerations of the X-15 Development, NSIA Meeting (1959-11-17). In: Gene Waltman, Black Magic and Gremlins: Analog Flight Simulations at NASA's Flight Research Center, NASA SP-2000-4520 (2000).

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