NASA's first human spaceflight program was Project Mercury in 1958.It was about a year after the former Soviet Union started the Space Age with the successful launch of the satellite£¬Sputnik 1.Testing the limits of the human body in space was an important aim of these two space programs.

Soviet cosmonaut£¬Yuri Gagarin£¬became the first person in space when he orbited the earth in a Vostok spaceship on April 12,1961.