Wouldn’t the soviets or any other adversary prepare against letting NASA capture their satellites? You need a very small amount of C4 in the satellite to destroy the shuttle in the event of capture. Tampering with other entity‘s satellites can best be done with satellites. That also frees resources needed for bringing life support systems to orbit.

But at that point if you're building in a self-destruct for a weapon that can be so dangerous it's worth sending a shuttle to take it away from you, surely it's better to adversarially trigger the self-destruct and not bother sending the shuttle. So the C4 option might simply be a bad idea: make it more difficult and costly to remove your weapon, rather than triggering your own self-destruct.