Greg Laden's Blog

Surveyor was a wonderful series of spacecraft -- if only they made it to their destination. In summer camp as a kid, I hung around the canteen waiting to hear news on radio on how they were doing. I know two crashed, but don't recall the postmortems on the causes. I got deep into 3, 6 and 7 because of their robotic aspects -- that shovel -- and because of 6's being the first to lift off the lunar surface and settle back down. (I believe one of the series didn't have the arm in order to save weight for something else, but I could be wrong.) I also know the JPL report kindly sent me by NASA on Surveyor 3 made a big impression because of a figure it had, one with two non-orthogonal coordinate systems overlaid on a picture of 3's work area. It was used to figure out where to position and place the arm and shovel.

I learned a lot from these reports, even as a junior high school kid:

• * How non-orthogonal coordinate systems can be really useful and not hard to deal with; they can be your friends, especially in coordinate-free formulations
• * How a series of commands could be sent to a controller remotely, and it wasn't necessary to assume feedback for them to be useful, akin to UDP vs TCP on the Internet
• * How sending commands to a motor controller was really not much different than writing assembly code for the computers I was just beginning to explore
• * How clever experimenters could use proxies for measures of interest, like using the amperage drawn by Surveyor's arm motors for how dense the material was it was trawling through
• * How simulations of activity could be used to plan and debug a complicated sequence of actions
• * How even the simplest of technical devices -- a magnet, a surveyors mark -- could be very useful if you had a camera and an arm

Posted by: ekzept | June 2, 2008 12:34 PM