The Voyagers
Where no spacecraft have gone before!
The renamed Voyager Interstellar Mission searches for the edge of the solar wind's influence (the heliopause) and exits the solar system.
More than 30 years after they left Earth, NASA's twin Voyager probes are now at the edge of the solar system. Not only that, they're still working. And with each passing day they are beaming back a message that, to scientists, is both unsettling and thrilling. The message is,
"Expect the unexpected."
Once Voyager is in interstellar space, it will be immersed in matter that came from explosions of nearby stars. So, in a sense, one could consider the heliopause as the final frontier.Read more about the Voyagers missions at the NASA JPL website.
Link: http://voyager.jpl.nasa.gov/mission/didyouknow.html
The first Earth orbiting satellite was Sputnik 1, which was launched 4 October 1957, and remained in orbit for several months. While Sputnik 1 was the first spacecraft to orbit the Earth, other man-made objects had previously reached an altitude of 100 km, which is the height required by the international organization Fédération Aéronautique Internationale to count as a spaceflight. This altitude is called the Kármán line. In particular, in the 1940's there were several test launches of the V-2 rocket, some of which reached altitudes well over 100 km.
The first manned spacecraft was Vostok 1, which carried Soviet cosmonaut Yuri Gagarin into space in 1961, and complete a full Earth orbit. There were five other manned missions which used a Vostok spacecraft. The second manned spacecraft was named Freedom 7, and it performed a sub-orbital spaceflight carrying American astronaut Alan Shepard to an altitude of just over 187 kilometres (116 mi). There were five other manned missions using at Mercury spacecraft, like Freedom 7.