After it has been delayed from December to February, due to some problems with the ECO sensors, the STS-122 mission has started today with the successful launch of the space shuttle Atlantis.

Despite weather concerns, the Mission Management Team gave a green light this morning, after loading Atlantis’ fuel tank with 500,000 gallons of liquid oxygen and liquid hydrogen and the liftoff was scheduled for 2:45 p.m. EST. The sky was cloudy at launch time, but rain and thunderstorms remained off to the west.

"All systems are go," launch director Doug Lyons told the astronauts. "I'd like to wish you a successful mission and safe return."

Replied shuttle commander Stephen Frick: "Looks like today's a good day, and we're ready to go fly."

Cheers and shouts could be heard throughout the space center as Atlantis, carrying the STS-122 crew and Columbus Laboratory, roared off the launch pad into the mid-afternoon sky to begin the 24th mission to the International Space Station.

At 2:53 p.m. EST NASA reported Atlantis is in orbit. The three main engines on Atlantis have shut down as planned and the external tank that held the cryogenic propellant for the engines has been jettisoned. The main engines fired throughout the 8 ½-minute flight into orbit. Atlantis is now speeding through low Earth orbit at about 17,500 mph in its chase of the International Space Station.

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.

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.

Click here to watch a NASA Video Overview of STS-122 Mission and here for a video presentation of Columbus module.

Atlantis is scheduled to arrive at the International Space Station on Saturday.