Summary: The countdown is on for the launch, scheduled for Wednesday morning NZ time, of the world's most powerful rocket. SpaceX's giant Falcon Heavy, will lift off from Cape Canaveral in Florida with thrust at liftoff equal to 18 Jumbo Jets all firing up simultaneously. It can blast 57 tons into orbit, and according to Space X and its CEO Elon Musk it's a stepping stone on the quest to send humans to Mars. We speak to Sarah Lewin who is covering the launch for space.com.
