The U.S. space shuttle Atlantis is on its way home after undocking from the International Space Station, beginning the last leg of its final voyage and of the 30-year U.S. shuttle programmme.Atlantis and its four-member crew separated from the ISS early Tuesday over New Zealand after an eight-day visit to deliver a year's worth of supplies to the orbiting outpost and haul trash and used equipment back to Earth. The shuttle flew one lap around the space station before maneuvering away for the last time.