Reuseable

(2nd of two)

It's expensive (~$70 million) to go into space when you need a brand new rocket every single time. If the same rocket can be used twice, that cuts the cost in half.

But think about the obstacles that must be overcome - enormous pressure and heat of course, plus a very tricky landing. Last month SpaceX failed in the attempt to bring a rocket back to earth safely because it ran out of hydraulic fluid.

See the animation below of how the concept is going to work later this year when SpaceX launches Falcon Heavy, and watch the rockets turn around to head back to the pad and land intact: