Are we a step closer to getting humans on Mars?
4 December 2014 Last updated at 08:56 GMT
An American space capsule that could help get humans to Mars is making its first test flight on Thursday.
The Orion capsule will be launched into space on a powerful Delta rocket from Cape Canaveral in Florida.
Professor of Astrophysics, Tim O'Brien, talks to Ricky about whether we are a step closer to getting humans on Mars.
More on this story - 'Mars ship' set for test flight.