"The vehicle's looking good and the weather's looking good, too," Shuttle Weather Officer Kathy Winters said.

Mission STS-122 is scheduled to launch at 4:31 p.m. EST from NASA's Florida launch base.

The mission marks he beginning of a new chapter in international space flight that will give Europe its first real foothold in space with the installation of the European Space Agency laboratory. Space travel has been dominated by Russia and the United States for half a century.

Atlantis will carry the European-developed Columbus laboratory and attach it to the International Space Station. Seven astronauts, including two from the European Space Agency, will fly aboard Atlantis.

Columbus is about 23 feet long and 15 feet wide, allowing it to hold 10 "racks" of experiments, each approximately the size of a phone booth. Five NASA racks will be added to the laboratory once it is in orbit. Each rack provides independent controls for power and cooling, as well as communication links to earthbound controllers and researchers. These links will allow scientists all over Europe to participate in their own experiments in space from several user centers and, in some cases, even from their own work locations.

The Columbus laboratory's flexibility provides room for the researchers on the ground, aided by the station's crew, to conduct thousands of experiments in life sciences, materials sciences, fluid physics and other research in a weightless environment not possible on Earth.

In addition, the station crew can conduct experiments outside the module within the vacuum of space, thanks to four exterior mounting platforms that can accommodate external payloads. With a clear view of Earth and the vastness of space, external experiments can run the gamut from the microscopic world of bacteria to the limitlessness of space. The first two experiment packages will fly to the station on the shuttle with the module.

Columbus will be installed by German astronaut Hans Schlegel, a physicist and German army paratrooper. He must make two space walks during the 11-day shuttle mission.

During the first walk, a giant robotic arm will lift Columbus out of the shuttle's payload bay. Schlegel and US astronaut Rex Walheim will then prepare the lab for docking. They will also replace a nitrogen tank assembly used to pressurize the ISS's outside cooling system.

Schlegel's duties also include testing all the seals on the dock and connecting electrical power, water and air cooling systems, air ducts and data cables so that Columbus becomes part of the space station, Schlegel said in an interview posted on the NASA website.

"It's not easy to imagine what kind of provisions you really need to make Columbus an integral part of the space station, interacting as well, and all that is done during the first day," Schlegel said.

Last month ISS astronauts Peggy Whitson and Dan Tani completed a final seven-hour spacewalk to finish hooking up the Harmony module to the International Space Station (ISS).

Harmony, which was delivered by the space shuttle Discovery, will serve as a docking port for the Columbus module.

Next year, a series of space shuttle missions will carry the components of a Japanese laboratory into orbit.

In February 2008 the mission STS-123 on Space Shuttle Endeavour will deliver the pressurized section of the Kibo (Hope) Japanese Experiment Logistics Module (ELM-PS) on the twenty-fifth mission to the International Space Station.

For April 2008 NASA plans the STS-124 shuttle mission which will deliver the Pressurized Module and robotic arm of the Kibo Module.