Can someone please give a step by step explanation of an orbital rendezvous by a spacecraft for a target that is orbiting the body it launched from? And if possible, can you explain how mission control is involved and what part computers play? When the RCS is active is it changing the spacecraft's orbit by miniscule amounts? This is what I know: NASA carried out Project Gemini to more fully understand orbital mechanics and to test its ability to carry out orbital rendezvous in addition to conducting EVAs and testing spacesuits. The main spacecrafts used in the project were the Gemini capsule and the Agena unmanned craft. The process of an orbital rendezvous: A target is already in orbit. The spacecraft launches into orbit, and uses its main engine to conduct a transfer maneuver to get into an orbit near the target. If the spacecraft is behind the target, it burns into a smaller orbit to catch up with its target. If the spacecraft is in front of the target, it burns into a larger orbit so the target can catch up to it. When spacecraft is close enough to its target (how close must this be?) its RCS takes over to carry out the docking maneuver can complete the rendezvous. I know I asked a lot, but I would be truly thankful if you could offer a response. P.S. - And if you happen to know any good books on orbital mechanics, could you please suggest them.