the way through the crew rotation for Lovell and Aldrin to become the prime crew of Gemini 12. Along with the deaths of Grissom, White, and Roger Chaffee in the fire of Apollo 1, this final arrangement helped determine the makeup of the first seven Apollo crews, and who would be in position for a chance to be the first to walk on the Moon. Missions In 1964 and 1965, two Gemini missions were flown without crews to test systems and the heat shield. These were followed by 10 flights with crews in 1965 and 1966. All were launched by Titan II launch vehicles. Some highlights from the Gemini program: On Gemini 4, Ed White became the first American to make an extravehicular activity (EVA, or "spacewalk") on June 3, 1965. Gemini 5 (August 21–29, 1965) demonstrated the 8-day endurance necessary for an Apollo lunar mission with the first use of fuel cells to generate its electrical power. Gemini 6A accomplished the first space rendezvous with its sister craft Gemini 7 in December 1965, with Gemini 7 setting a 14-day endurance record for its flight. Gemini 8 achieved the first space docking with an unmanned Agena target vehicle. Gemini 10 established that radiation at high altitude was not a problem, further demonstrated the ability to rendezvous with a passive object, and was the first Gemini mission to fire the Agena's own rocket. Michael Collins would be the first person to meet another spacecraft in orbit, during his second successful EVA. Gemini 11 first direct-ascent (first orbit) rendezvous with an Agena Target Vehicle, docking with it 1 hour 34 minutes after launch. Set a crewed Earth orbital altitude record of in September 1966, using the Agena target vehicle's propulsion system. This record still stands as of 2022. On Gemini 12, Edwin "Buzz" Aldrin became the first space traveler to prove that useful work (EVA) could be done outside a spacecraft without life-threatening exhaustion, due to newly implemented footholds, handholds, and scheduled rest periods. Rendezvous in orbit is not a straightforward maneuver. Should a spacecraft increase its speed to catch up with another, the result is that it goes into a higher and slower orbit and the distance thereby increases. The right procedure is to go to a lower orbit first and which increases relative speed, and then approach the target spacecraft from below and decrease orbital speed to meet it. To