How to put a human on Mars: Artificial gravity
22 July 2013 Last updated at 18:28 BST
An Imperial College team discuss how we could create artificial gravity to prevent muscle and bone loss in a human crew on a trip to Mars.
They start in the playground with a demonstration of how centrifugal forces can be used to generate artificial gravity.
Video journalist: Neil Bowdler. Animation: George Spencer. Music: Spiro.