It was perfected (for some value of "perfect") in the 60s, during the Gemini program: https://en.wikipedia.org/wiki/Agena_target_vehicle https://en.wikipedia.or

It was perfected (for some value of "perfect") in the 60s, during the Gemini program: https://en.wikipedia.org/wiki/Agena_target_vehicle https://en.wikipedia.org/wiki/Agena_target_vehicle