A look at Nasa's rover prototype

Nasa is putting its newest technology through its paces in the Arizona desert, an environment it says provides a good simulation of the surface of the moon or Mars.

A rover prototype, the Space Exploration Vehicle, has a pressurised cabin, in which crew can live for up to 14 days.

Nasa astronaut Mike Gernhardt is in charge of the design - and has spent some time living on board to see how it works in practice.