Sunday, November 23, 2008

Apollo 12 mission analyzer

Something you'd probably never see for a space mission in the age of ubiquitous computers is this "Guidance and Navigation Mission Analyzer" from Raytheon. It consists of three concentric circular scales on the front and two on the back. It's basically a portable flight plan for the key events of the mission. These were used by engineers and support team members. Since each mission was different, there were separate analyzers provided for each Apollo mission.

To use it, you align the arrow on the blue ring for the first key event, Translunar Insertion, with the actual day and time that it occurred, as shown on the outer ring. Then, by rotating the inner ring so that its arrow points to a day and time of interest, you can read in the cutout window the events scheduled to transpire at that time.

The back of the analyzer deals with launch, lunar module activities, and Earth reentry activities. When I scanned in the image above, I set the window to show the activities during EVA 2 at the Surveyor 3 site.

I would have killed to have something like this back during the missions! Circular slide rules still have their uses today, primarily by pilots.

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