How SpaceX flips a rocket upright before landing

For sixty years, rockets were treated as single-use garbage that we simply dumped into the ocean after launch. To make them reusable, SpaceX engineers had to figure out how to parallel park a 15-story building falling from space. They use nitrogen cold gas thrusters at the top of the booster to violently flip it backwards at supersonic speeds, reigniting the engines at the last possible second just to show off.