1. Project Mercury (1958-1963): This was the first human spaceflight program for the United States. Its primary goals were to orbit a manned spacecraft around Earth and safely bring the astronaut back to Earth.
2. Project Gemini (1964-1966): This program followed Mercury and focused on developing the techniques needed for a lunar landing. It involved longer-duration missions, spacewalks, and rendezvous maneuvers.
3. Project Apollo (1961-1972): This was the culmination of the earlier programs, designed to land humans on the Moon. It involved developing powerful rockets, lunar modules, and the Apollo spacecraft that carried astronauts to the Moon and back.
