Posted by Patrick on December 31, 1999 at 19:53:29:
In Reply to: Re: Speed of Hubble posted by Meat-pizza on December 29, 1999 at 12:34:48:
> > How fast were the astronauts moving while on the Hubble doing repairs.
> > Rumors have it that it was 4000 mph. Can you inlighten us?
>
> The astronauts actually move pretty slowly while they repair the telescope, if they moved at 4000 mph they'd have all their tasks done in a couple of seconds!
> Jokes aside, I think what you are asking was the relative speed of the shuttle and HST to someone standing on earth, which was about 17,500 mph (or 28,163 km/h for you metric fanatics). The relative velocity between the astronauts and the shuttle was zero (they were traveling at the same speed and direction), so they have really had no sensation of how fast they were traveling.
Where does the speed 17 500 mi/h come from? It seems too "exact" to be true. It would appear the real speed is something else, and that the speed was rounded to 17 500. If this is true, then you can't just convert to metric using exact conversions. You have to calculate it the same way as done with miles and round off to an even number the same way miles was done.
There is a such thing as significant figures that applies when values are converted from one unit to another.