But Deep Space Industries Chairman Rick Tumlinson, a longtime booster of private space efforts, said the company sees itself as the 21st-century version of the "settlers and shopkeepers" who followed the Lewis and Clark expedition into the American West.

CNN: 'Fireflies' to scope out space rocks for mining

Once in flight, the plane will disengage from its capsule and return to the ground, while the capsule launches multistage booster rockets to propel it into space orbit or to the International Space Station.

BBC: The futurist: The world��s largest plane

NASA's next-generation rocket, a behemoth of a booster expected to launch astronauts deeper into space than ever before, has passed a major design milestone, space agency officials announced Wednesday.

MSN: Giant deep-space rocket passes key test - Technology & science - Space - Space.com | NBC News

This time it was not the silvery pencil of an Atlas booster carrying the 77-year-old Senator into space but the great technological temple of a space shuttle.

CNN: Victory Lap

During a question-and-answer session with "3D Robotics" editor-in-chief Chris Anderson, Musk said that affordable commercial space travel will never be possible with the current model, which relies on single-use booster rockets.

CNN: Elon Musk: Our future in space depends on reusable rockets

Vasily Moroz from the Russian Space Research Centre said the two sides had considered using a US-built probe with a Russian booster rocket and descent module, but that the project was drawn to a halt by funding issues.

BBC: Mars rover (Nasa)