What you’re seeing in the video below is a 40-meter tall SpaceX rocket booster, weighing more than 20 tons, fly itself back to Earth from space and land precisely on a target at Cape Canaveral. What you may be wondering is, how did it do that?

http://www.nextgov.com/emerging-tech/2017/02/spacexs-self-landing-rocket-flying-robot-s-great-math/135600/?oref=NextgovFB