[Des]

Des asked the Naked Scientists:
   
Hi, do space shuttles have speedometers that work in space? If so how do they gauge their speed?

Cheers

Dublin Bus Driver.

What do you think?

[LeeE]

I think that radar would be the simplest solution.

[Soul Surfer]

There are several ways  A variant of GPS is probably the most accurate.  I say a variant because normal GPS does assume that you are reasonably close to the surface of the earth space shuttles do go a few hundred miles up and this may require more calculation.