On September 23, 2014 at 10:52 UTC the private U.S. unmanned supply spacecraft, the Dragon (CRS-4 flight), was successfully docked to the International Space Station. The linkup operation was carried out by astronauts Alexander Gerst (Germany) with the help of the giant 17-meter Canadarm. The Dragon spacecraft was maneuvered into position and attached to a berthing port on the space station's Harmony module. The unmanned spacecraft delivered about 2.5 tons of supplies for the space station crew and for experiments being conducted aboard the ISS. The Dragon spacecraft will stay attached to the space station until mid-October, when astronauts will install research specimens and other hardware for return to Earth.