The largest and most powerful rocket ever built has blasted off from Texas but blew up within minutes in a test flight that its makers, SpaceX, hope will be the first step on a human journey to Mars. After a cancelled launch earlier this week due to a pressurisation issue, the 120-metre Starship rocket system took off at 8:33am local time on Thursday. It gathered speed but then started to spin at altitude before exploding about four minutes after leaving the ground. It appeared that the two sections of the rocket system – the booster and cruise vessel – were unable to separate properly after takeoff, possibly causing the spacecraft to fail