Timeline
1915	Robert Goddard proves validity of rocket propulsion principles in a vacuum.
1926	Goddard launches first liquid-fuel rocket engine.
1932	Wernher von Braun begins experimenting with rocket engines for his doctoral dissertation.
1933	Russia's first liquid-fueled rocket is launched.
1934	Von Braun built his first successful rocket, the A-2.
1942	Von Braun achieves the first successful launching of a V-2 rocket.
1950	A two-stage bumper rocket is launched from Cape Canaveral.
1957	Sputnik I is launched by liquid-fueled rocket built by Sergei Korolev.
1958	The U.S. launches Explorer 1, signalling the beginning of the space program.
1959	Russian lands a Luna probe on the moon and takes the first pictures of its far side.
1961	Russian Yuri Gagarin orbits Earth one time.
1961	Alan Shepard is launched 115 miles into space, lands 15 minutes later in Atlantic Ocean.
1962	John Glenn orbits Earth three times in a Mercury capsule, Friendship 7.
1962	Mariner 2 flies past Venus, the first probe to fly beyond another planet.
1963	RL-10 rocket engine, the world's first high-energy liquid hydrogen engine.
1963	Valentina Tereshkova, Soviet cosmonaut, becomes the first woman in space.
1963	The first communications satellite to reach synchronous orbit, Syncom II, is launched.
1964	First space walk, U.S. Gemini program.
1965	Early Bird is launched for use by communications services.
1965	Gemini spacecraft makes first rendezvous in space between two spacecraft.
1969	Apollo 11 moon landing, Neil Armstrong is first person to walk on moon.
1971	Earth-orbiting space station, USSR.
1973	Skylab is placed in orbit.
1976	Mars space probes, NASA's Viking I and Viking II, launched.
1977	U.S. Space Shuttle program begins.
1981	Columbia Space Shuttle, the first reusable winged spaceship, is launched.
1997	The robotic explorer, Sojourner, lands on Mars.
1997	Pioneer 10 spacecraft exits the solar system for interstellar space, and is still functioning.
1997	Discovery Shuttle mission with John Glenn aboard at age 77.