Astronauts have installed the European space laboratory Columbus on the orbiting International Space Station, giving Europe an important foothold for the deeper exploration of space.
"The European Columbus module is officially part of the International Space Station," said French space engineer Leopold Eyharts, with NASA broadcasting live images of the installation, which took place late on Monday.
The move gives European space agencies a presence alongside US and Russian astronauts on the ISS, a preparation point for future human missions to Mars.
Two astronauts from the US space shuttle Atlantis earlier made a seven-hour space walk to prepare Columbus for its hook-up to the station, orbiting 350 kilometers above the Earth.
They fixed fittings to Columbus so it could be grabbed and maneuvered into position by the station's robotic arm, for attachment to the station's Harmony module.
The two billion-dollar, 10-tonne Columbus laboratory represents a milestone in Europe's role in space. Paid for mostly by Germany, Italy and France, it is the first ISS addition not made in the United States or Russia.
The laboratory will be used for biotechnology and medicine experiments involving microgravity.
The spacewalkers also had to install panels to protect it from the impact of micro-meteorites.
NASA plans to attach another laboratory, the Japanese module Kibo, to Harmony in March.
Clearing up concerns that launch debris may have damaged the shuttle as it took off from Florida, mission chief John Shannon said on Sunday that the thermal shield on Atlantis's nose and wing forward edges were in perfect condition.