View of the Dragon CRS-3 cargo spacecraft.
SpaceX's CRS-3 Dragon mission has ended today, splashing down in the Pacific Ocean at about 1 pm MDT. It was the 4th time that the company had successfully sent an unmanned cargo spacecraft to rendezvous or dock with the ISS. Using the Canadian-built robotic arm, astronauts pulled the craft away from the docking port and gently released it on its own. The craft was then moved away from the station using thrusters. Eventually the craft spent 5 hours of free floating time while engineers checked all systems and made sure the outer cargo doors were shut, then firing a de-orbit burn to return to the surface.
You can find a great description of the undocking and the mission of CRS 3 at: