There were twelve Gemini missions overall, each specifically designed to test equipment and gradually increase the knowledge needed to put a human on the moon. The first manned Gemini mission, Gemini 3, blasted off on March 23, 1963. Its objective was to test the new spacecraft’s maneuverability, with the crew using rockets to change the ship’s orbit. It was also the last mission to be controlled from Cape Canaveral Air Force Station; from then on, mission control was shifted to Houston, Texas. The next mission, Gemini 4, involved the first American “walk” in space – although, to the Americans’ dismay, the Soviets had beaten them to this by three months. During this Gemini mission, Ed White depressurized the cabin and floated out into space for twenty minutes, tethered to the spacecraft by a long cord. The next Gemini missions came in quick succession. Gemini 5 stayed in orbit for eight days – the length of time needed for a moon landing – and subsequent missions attempted to practice rendezvous. The main challenge of lunar landings was transporting the astronauts to and from the moon’s surface safely. Obviously, they couldn’t use the same method used for reentering Earth’s atmosphere – these were single-use landings. Instead, NASA decided to develop a new procedure called lunar-orbit rendezvous. This would involve the astronauts putting the spacecraft into orbit around the moon, and using a smaller “bug” to leave the mothership and transport them to the surface. Upon leaving, the astronauts would launch the bug into lunar orbit and rendezvous with the mothership. Then they would have to dock their bug with the ship and transfer over to it. This was a great idea, but it was completely new territory. What problems and challenges would they face? With this in mind, Gemini 6-A went into orbit around Earth on December 15, 1965. Its objective was to rendezvous with Gemini 7, already in orbit. And for three orbits of the Earth, the two spacecraft managed to stay within 100 yards of each other. NASA had proved that, with skillful piloting, a physical docking of a bug with a mothership was possible. A few months later, on March 16, 1966, it was accomplished, when Gemini 8 crewmembers Neil Armstrong and David Scott successfully docked their spacecraft with an unmanned Agena Target Vehicle. These accomplishments marked the beginning of the end of Soviet space dominance, and paved the way for Apollo – the program to send humans to the moon.