A Nasa scientist has proposed using the replacement to the space shuttle to land on a near-Earth asteroid.
The Crew Exploration Vehicle (CEV) is due to make its maiden flight in 2014, with the eventual aim of ferrying astronauts to and from the Moon.
Dr Paul Abell said such a mission could help efforts to protect against an asteroid on course to hit Earth.
More: http://news.bbc.co.uk/2/hi/science/nature/6452311.stm