This marks their fourth successful landing of stage one. After accelerating to a speed of nearly 1600 meters per second(3579Mp/H) the stage one booster sucessfully fell back to earth and landed on an unmanned drone ship in the ocean using nothing but its on board stabilizers and booster. This mission carried over 2 Tons of supplies waiting to dock with the international space station very soon.
Their goal is to get the cost of transporting materals into space below $10,000/kg. They also announced that this fall they will be relaunching one of the recycled stage 1 boosters!