Slide rule use in space

[Accutron]

(05-06-2016 01:59 PM)4ster Wrote:  my very smart, slightly older, civil engineering friend snorted and said there was no way a slide had the precision necessary to navigate a space craft.

I guess that's why NASA hires aeronautical engineers for such things instead of civil engineers. The early space program was built with slide rules. Here's a quote from NASA engineer Bob Bobola:

"Computers were around, but they were great big in size. Most reports were handwritten, and a lot of the calculations – weight, center of gravity – were mostly done by hand using a slide rule. It's a wonder we were successful."

Faith 7 (Mercury-Atlas 9) lost altitude readings on the 20th orbit, and lost power to the automatic stabilization and control system on the 21st orbit. Gordon Cooper had to manually calculate everything with a Bulova Accutron Astronaut 214 wristwatch and a circa 1949 Keuffel & Esser slide rule, and pilot the capsule manually. It was the most accurate splashdown in the whole Mercury program, landing about four miles from the recovery ship.