This undated artist rendering provided by Space Exploration Technologies (SpaceX), shows Space Exploration Technology's new rocket Falcon Heavy. (AP)
This file photo from April 12, 1961, shows Soviet cosmonaut Yuri Alexeyevich Gagarin in the Vostok 1 command capsule. Gagarin became the first man in space. Gagarin orbited earth one time at an altitude of 187 3/4 miles (302 kilometers) for 108 minutes at 18,000 miles an hour. (-/AFP/GETTY IMAGES)
Elon Musk, CEO of Space Exploration Technologies Corp, speaks during a news conference at the National Press Club April 5, 2011 in Washington, DC. (Brendan Smialowski/Brendan Smialowski / Getty Images)
Children look at a poster depicting Yuri Gagarin, the first cosmonaut, in the Russian-leased Baikonur cosmodrome, Kazakhstan, Tuesday, March 29, 2011. (Dmitry Lovetsky / AP/Dmitry Lovetsky / AP)