SpaceX has finally landed its Falcon 9 rocket on a drone ship at sea, after launching the vehicle into space this afternoon. It's the first time the company has been able to pull off an ocean landing, after four previous attempts ended in failure. Today's success is a crucial milestone for SpaceX, as it shows the company can land its rockets both on solid ground and ocean. Scientists have found gravitational waves? The significance of that finding explained by Loren Grush and The Verge Video team: www.youtube.com/watch?v=tlch-DWaQE0&list=PL39u5ZEfYDEMEdiwwbNzybGP65-o-OTez&index=3