How astronauts prepare to go into space - underwater!

The landing of the Curiosity Rover on Mars last week was one of the few stories that grabbed people's attention away from the Olympics.

But it's not just other planets that scientists at Nasa are keen to explore. British astronaut Tim Peake has been working on a mission to get space explorers travelling to asteroids.

He's taken part in a big mission underwater to test future equipment and techniques for space exploration.

The NASA project took him to the bottom of a training tank to simulate a very specific mission that lasted nearly 7 months.