'Rocket entrepreneur Elon Musk believes he can get the cost of a round trip to Mars down to about half a million dollars.
'The SpaceX CEO says he has finally worked out how to do it, and told the BBC he would reveal further details later this year or early in 2013.
'Musk is one of NASA's new commercial partners, building systems to take cargo and crew to the space station.
'He has developed his own rocket and a capsule for the purpose.
'The Falcon 9 launcher and the Dragon vessel are expected to give the first full demonstration of their capabilities next month on an unmanned sortie to the orbiting outpost.' (BBC News article & audio stream).