Project Gemini was NASA’s second human spaceflight program. It was a United States government civilian space program started in 1961 and concluded in 1966. Project Gemini was conducted between projects Mercury and Apollo. The Gemini spacecraft carried a two-astronaut crew. Ten crews flew low Earth orbit (LEO) missions between 1965 and 1966. It put the United States in the lead during the Cold War Space Race with the Soviet Union. Its objective was to develop space travel techniques to support Apollo’s mission to land astronauts on the Moon. Gemini achieved missions long enough for a trip to the Moon and back; perfected working outside the spacecraft with extra-vehicular activity (EVA); and pioneered the orbital maneuvers necessary to achieve rendezvous and docking. With these new techniques proven in Gemini, Apollo could pursue its prime mission without doing these fundamental exploratory operations. All Gemini flights were launched from Cape Canaveral Air Force Station Launch Complex 19 (LC-19), in Florida. Its launch vehicle was the Gemini–Titan II, a modified Intercontinental Ballistic Missile (ICBM). Project Gemini was the first program to use Houston as the Mission Control for its flights. The astronaut corps that supported Project Gemini included the “Mercury Seven,” “The New Nine” and the 1963 astronaut class. During the program, three astronauts died in air crashes during training, including the prime crew for Gemini 9. This mission was performed by the backup crew, the only time that has happened in NASA’s history. Gemini was robust enough that the United States Air Force planned to use it for the Manned Orbital Laboratory (MOL) program, which was later canceled. Gemini’s chief designer, Jim Chamberlin, also made detailed plans for cislunar and lunar landing missions in late 1961. He believed Gemini could perform lunar operations before Project Apollo, and cost less. NASA’s administration did not approve those plans. In 1969, McDonnell-Douglas proposed a “Big Gemini” that could have been used to shuttle up to 12 astronauts to the planned space stations in the Apollo Applications Project (AAP). The only AAP project funded was Skylab – which used existing spacecraft and hardware – thereby eliminating the need for Big Gemini.