Project Gemini was
NASA's second
human spaceflight program. It was a
United States 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 space rendezvous and docking. With these new techniques proven in Gemini, Apollo could pursue its prime mission without doing these fundamental exploratory operations.
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 had happened in NASA's history to that date.
Gerard Kitchen O'Neill (February 6, 1927 – April 27, 1992) was an
American physicist and space activist. A faculty member of
Princeton University, he invented a device called the
particle storage ring for high-energy physics experiments. Later, he invented a magnetic launcher called the
mass driver. In the 1970s, he developed a plan to build human settlements in outer space, including a
space habitat design known as the
O'Neill cylinder. He founded the
Space Studies Institute, an organization devoted to funding research into
space manufacturing and
colonization.
O'Neill began researching high-energy particle physics at Princeton in 1954 after he received his doctorate from Cornell University.
Two years later, he published his theory for a particle storage ring. This invention allowed particle physics experiments at much higher energies than had previously been possible. In 1965 at Stanford University, he performed the first colliding beam physics experiment.
While teaching physics at Princeton, O'Neill became interested in the possibility that humans could live in outer space. He researched and proposed a futuristic idea for human settlement in space, the O'Neill cylinder, in "The Colonization of Space", his first paper on the subject. He held a conference on space manufacturing at Princeton in 1975. Many who became post-Apollo-era space activists attended. O'Neill built his first mass driver prototype with professor Henry Kolm in 1976. He considered mass drivers critical for extracting the mineral resources of the Moon and asteroids. His award-winning book The High Frontier: Human Colonies in Space inspired a generation of space exploration advocates. He died of leukemia in 1992.
