Europe's sophisticated space freighter, Johannes Kepler, has docked with the International Space Station (ISS).

欧洲精密的太空飞船开普勒号已与国际空间站成功对接。

The unmanned robotic truck attached itself to the Zvezda module¹ on the rear of the platform at 1559 GMT.

The ship is delivering new supplies of fuel, food, air, and equipment to the ISS's astronauts.

Kepler is totally automatic and used its own computerised systems and sensors² to find the station in orbit and make the connection.

Having travelled half a million kilometres since its launch eight days ago, the freighter made the docking with an accuracy that could be measured in centimetres.

Confirmation³ that the seal between the freighter and Zvezda was fully⁴ satisfactory came at 1608 GMT.

"It went as smooth as we could have dreamed it would," European Space Agency Director-General Jean-Jacques Dordain told BBC News.

The 20-tonne ship's mission managers, based in Toulouse, France, oversaw⁵ the final automated⁶ manoeuvres（调动，演习） but had no need to intervene.

Italian astronaut Paolo Nespoli and Russian cosmonaut Aleksandr Kaleri were inside Zvezda when Kepler made its final approach.

They will need to scrub（用力擦洗） the air inside the ship before entering.

The docking permits the US shuttle Discovery to launch from Florida later in the day. It has a date with the ISS, too, and will be carrying up six visiting astronauts and a smart humanoid robot（人形机器人） .

The truck - also known by its generic⁷ name of Automated Transfer Vehicle (ATV) - is the second such ship launched to the ISS by the European Space Agency.

The first, nicknamed Jules Verne, completed its mission in 2008.
 
Mission control for the freighter is in Toulouse in southern France

One of the freighter's main tasks in the coming months will be to raise the altitude of the station, which is currently at about 350km.

The ISS has a tendency to fall back to Earth over time as it drags through the top of the atmosphere.

Every few weeks the freighter will fire its thrusters（推进器） to accelerate the platform, taking it higher into the sky.

The freighter will be used like a store cupboard by the ISS astronauts.

They will go into the pressurised（增压的） vessel⁸ to obtain food, clothing and equipment when they need it. Additional fuel will be piped across to the main station complex; air will simply be vented⁹（排放） from taps.

As Kepler's supplies are depleted¹⁰, the void will be filled with rubbish. The vehicle will take this waste into a controlled burn-up over the Pacific Ocean when it leaves the station sometime from June onwards.