SpaceX is testing another rocket and posting the results to YouTube. On Tuesday they launched the the Falcon 9 test rig code named Grasshopper. The rocket completed a divert test. This shows how the craft can perform more aggressive steering maneuvers than have been attempted in previous flights.
Grasshopper is taller than a ten story building. This can make steering it particularly challenging. This task is an important part of landing the rocket precisely back at the launch site after reentering from space.