NASA is ready for Atlantis launch and the crew of STS-122 mission has arrived in Florida. The official countdown commenced on countdown Monday evening at 5 p.m. EST. The launch time is scheduled for February 7 at 2:45 p.m. EST from NASA's Kennedy Space Center in Florida.

Last week, NASA has solved a technical problem that could affect the Atlantis launch.

During Atlantis’s launch preparations the NASA technicians noticed a small section of a braided metal hose that was bent in a shape similar to the Greek letter Omega. The radiator retract hose, part of the shuttle's cooling system that carries Freon, is designed to flex, but the engineers wanted to make sure they were not overlooking potential problems.

They designed and tested a tool to guide the hose back into the storage box. The program managers gave the go ahead to close payload bay doors using the tool on Sunday evening.

After the arrival of the astronauts at Kennedy Space Center, the STS-122 mission commander Steve Frick said the team is confident in Atlantis’ condition.

Frick noted the work of NASA and contractor specialists throughout the agency's space flight centers for modifying a connector in the external tank's engine cutoff low-level fuel sensor system. A faulty connector postponed two launch attempts in December.

"Atlantis is ready to go fly," said Charlie Blackwell-Thompson, assistant NASA Test Director.

"We're feeling very good about this opportunity. We'll keep looking at the weather, but we're very happy about the condition of Atlantis," Frick said.

A veteran space flier, Navy Cmdr. Stephen N. Frick, will command the STS-122 shuttle mission and Navy Cmdr. Alan G. Poindexter will serve as pilot. Mission specialists include Air Force Col. Rex J. Walheim, Stanley G. Love, Leland D. Melvin and European Space Agency astronaut Hans Schlegel. Poindexter, Love and Melvin will be making their first spaceflight. Expedition 16 Flight Engineer Daniel Tani will return home with the STS-122 crew.

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.

NASA has scheduled three spacewalks for the STS-122 mission. On flight day 4, Walheim and Schlegel’s main task will be to prepare the Columbus module for installation on Harmony. They will install the Power Data Grapple Fixture on Columbus, which will allow the space station’s robotic arm to grab the module and move it from the shuttle’s payload bay to Harmony. The spacewalkers also will begin work to remove the Nitrogen Tank Assembly, a part of the station’s thermal control system, from the P1 truss. The assembly needs to be replaced because the nitrogen is running low.

On flight day 6, Walheim and Schlegel will remove the old NTA and temporarily store it on an equipment cart. They will then install the new one. The old NTA will be transferred to the shuttle’s payload bay for return home.

On flight day 8, Walheim and Love will install two payloads on Columbus’ exterior: SOLAR, an observatory to monitor the sun; and the European Technology Exposure Facility (EuTEF) that will carry eight different experiments requiring exposure to the space environment. The spacewalkers also will move a failed control moment gyroscope from its storage location on the station to the shuttle’s payload bay for return to Earth.

STS-122 is the 24th shuttle mission to the International Space Station.