"Andrew Thompson" wrote in message ...

But, would ion engines be practical for maneuvering
close to the shuttle (the inspection craft would
obviously need to 'traverse' the shuttle)?

Rather than have it in a separate orbit, why not carry it?

http://www.astronautix.com/craft/aercam.htm
http://spaceflight.nasa.gov/station/assembly/sprint/
http://aercam.nasa.gov/

Maybe 50kg if you go wild on a cargo bay dock for the full-
sized AERCam.

Mike Miller, Materials Engineer