Two astronauts made quick work of a space-walk on Tuesday despite a brief communications blackout, Russian mission control said.
Russian cosmonaut Gennady Padalka and US astronaut Michael Fincke finished a scheduled six-hour job in four and a half hours outside the International Space Station, where they have been based since April.
They installed equipment that will enable the European Space Agency to dock its first cargo ship - the Automated Transfer Vehicle (ATV) - at the station.
"They have already gone back in and closed the hatch," a mission control spokeswoman said. "They worked so well that they managed to do everything quicker than planned."
But the walk was not without hitches. The astronauts lost contact for around 20 minutes when the station shifted after the equipment controlling its position became overloaded.
The movement severed communications, but engineers on the ground swiftly re-aligned the station's position by switching on the engines of one of the modules. "It was all quickly fixed and not a major problem," the spokeswoman said.
The astronauts are due to perform another space-walk next month to make further preparations for the ATV, seen as a major contribution by Europe to the station which is predominantly serviced by Russia and the United States.
Although the European Space Agency has sent its astronauts to the station on short-term missions to conduct experiments, the provision of a cargo ship to ferry supplies to the station is considered more useful to its upkeep.
The first ATV, named the Jules Verne, is due to be launched next year and will provide a welcome helping hand as Russia struggles with the burden of being the sole lifeline to the station while US space shuttles remain grounded.
Russia has launched all manned and cargo ships to the orbital platform since February 2003, when the Columbia shuttle disintegrated on re-entry, killing the seven crew aboard and prompting NASA to withdraw the remaining fleet from service.
ATVs are capable of carrying a much bigger load of food, equipment and fuel than Russia's Progress cargo craft, which is the only way of getting supplies to the station at the moment.
The European vehicles are also big enough for astronauts based on the ISS to be able to work inside them once they dock.