(Sen) - Japan's third HTV unmanned cargo ship, named Kounotori, unberthed from the space station on Wednesday September 12, clearing the way for SpaceX's Dragon spacecraft which is scheduled to arrive with fresh supplies in October.
The HTV was unberthed from the station's Harmony node and was moved to its release position by the ISS's robotic arm. It was released at 3.50pm UTC and is now heading back to Earth where it will burn up during a controlled re-entry over the Pacific Ocean, incinerating the vehicle and the trash onboard.
Developed and operated by the Japan Aerospace Exploration Agency (JAXA), the HTV (whose long title is the H-11 Transfer Vehicle) is an unmanned cargo spacecraft that delivers supplies to the International Space Station (ISS).
The spacecraft had arrived at the ISS on July 27 delivering several tonnes of supplies which included fresh food, the YouTube SpaceLab winning experiments, five cubesats and a fish tank.
The departure marks the end of the third successful HTV mission. HTV's first mission to the ISS launched on September 11, 2009 and successfully demonstrated the cargo ship's autonomous and remotely-controlled rendezvous capabilities. HTV1 re-entered Earth's atmosphere on November 2, 2009. The second HTV flight - HTV2 - launched on January 22, 2011 and completed its mission in March 2011.
The HTV's departure has left a parking slot for SpaceX's Dragon spacecraft. SpaceX recently carried out a 'wet dress rehearsal' - a launch readiness test that simulates the countdown of the Falcon 9 rocket - which is being prepared to lift off from Cape Canaveral in early October. The mission is the first of twelve contracted resupply missions that NASA is outsourcing to SpaceX, a US space business set up by entrepreneur Elon Musk. SpaceX demonstrated the Dragon's ability to berth with the ISS in May this year.
Meanwhile, Europe's third Automated Transfer Vehicle (ATV3) called Edoardo Amaldi has begun preparations for its departure. Edoardo Amaldi is scheduled to leave the space station on September 25. The space freighter has already been loaded with over a tonne of trash and liquid waste which will burn up with the spacecraft during re-entry on September 26.
On Friday September 14 the ATV will deliver its final boost of the station's orbit ahead of its departure preparations. The boost should lift the orbiting outpost by 2.3 kilometres.
It's a busy transfer window for the space station, with three crew members due to leave on September 16. Joe Acaba, Expedition 32 Commander Gennady Padalka and flight engineer Sergei Revin will return to Earth in their Soyuz TMA-04M spacecraft. Their return will complete 125 days in space since their launch from Kazakhstan on May 15, including 123 days on the station.
Kounotori 3 successfully re-entered the atmosphere at 2:27 p.m. on September14 (Japan Standard Time.)