That sort of mission is mostly speculation. Nabbing a Soviet spy satellite would probably be suicide, they could have easily had scuttling charges onboard that would destroy both the satellite and the shuttle.
What is known is that it was designed to go to a polar orbit, where many spy satellites are, deploy a satellite and return to the launch site after a single orbit. It's that "single orbit" part that particularly necessitates the large cross-range capability, since 90 minutes later the launch site will about 1500 miles to the east of where it was. If landing after a single launch weren't necessary, they could just orbit for a day and wait for the landing sight to come around again. Deploying a satellite in a single orbit would be an incredible feat, but capturing one in a single orbit is just too far-fetched.
The idea of doing this was apparently to launch a US spy satellite quickly without giving the Soviets much time to track the exact orbital parameters the satellite was being deployed into. TBQH it doesn't make a whole lot of sense to me, unless the spy satellites themselves are presumed to be stealthy to Soviet radars. Maybe that was the case. I can see why the Soviets thought it was a nuclear bomber. Anyway, the Shuttle never actually went to polar orbit at all, so in this sense you could say the Shuttle never fulfilled its purpose.
What is known is that it was designed to go to a polar orbit, where many spy satellites are, deploy a satellite and return to the launch site after a single orbit. It's that "single orbit" part that particularly necessitates the large cross-range capability, since 90 minutes later the launch site will about 1500 miles to the east of where it was. If landing after a single launch weren't necessary, they could just orbit for a day and wait for the landing sight to come around again. Deploying a satellite in a single orbit would be an incredible feat, but capturing one in a single orbit is just too far-fetched.
The idea of doing this was apparently to launch a US spy satellite quickly without giving the Soviets much time to track the exact orbital parameters the satellite was being deployed into. TBQH it doesn't make a whole lot of sense to me, unless the spy satellites themselves are presumed to be stealthy to Soviet radars. Maybe that was the case. I can see why the Soviets thought it was a nuclear bomber. Anyway, the Shuttle never actually went to polar orbit at all, so in this sense you could say the Shuttle never fulfilled its purpose.