Project Mercury Begun in 1958 and completed in 1963,Project Mercury was the first major u.s program to establish a human presence in space. The objectives of the program, which made six human flights from 1961 to 1963. To successfully orbit a manned spacecraft around earth. To investigate human kinds ability to function in space. To recover both occupant and spacecraft. Each Mercury spacecraft carried one astronaut. There were seven Mercury astronauts, all military test pilots. Six of them (Alan shepard, Gus Grissom,Gordon cooper , and Wally Schirra)flew aboard the Mercury spacecraft. The seventh ,deke slayton, was grounded due to a minor medical aliment but eventually flew as a crewman aboard the Apollo-Soyuz test project in 1975.
Project Gemmi (named for the crew of two astronauts flying aboard each Gemini spacecraft) was the second human space flight program initiated by the United states. Operating between Mercury and Apollo , project Gemini experience by developing and testing the techniques for advanced space travel and long-duration space operations necessary to land humans on the moon.Gemini missions invoked the first American extravehicular activity and new orbital maneuvers including rendezvous and docking. The objectives of the Gemini program were:Gain astronaut experience with long duration space flights. Perfect methods of reentry and landing the spacecraft. Study the effects of weightlessness on astronauts during long flights.