According to NASA officials, the launch of space shuttle Atlantis will be launched no sooner than January 24 and a takeoff date of early February is also considered.

John Shannon, deputy manager for the Space Shuttle Program, said that the schedule depends on test results and modifications to a fuel sensor system connector on the external fuel tank Atlantis will use for launch on its STS-122 mission to the International Space Station.

Technicians at NASA's Kennedy Space Center, Fla., will modify a replacement connector for the one that was removed. Metal pins inside the connector will be soldered to the socket, Shannon explained. The new connector is scheduled to be in place by Jan. 10.

Known as Engine Cut-Off (ECO) sensors, the instruments sit on the bottom of Atlantis' 15-story external tank and serve as liquid hydrogen fuel gauges that ensure a shuttle's three main engines shut down before their hydrogen supply runs dry after liftoff.

"We're fairly confident that if the problem is where we think it is, that this will solve that," Shannon said.

Shannon also added that the connector is undergoing intensive testing at NASA's Marshall Space Flight Center in Huntsville, Ala.

Atlantis, which will carry the European space laboratory Columbus to the International Space Station, had been set for takeoff December 6 but was eventually delayed until January 10 after several scrapped launches blamed on the failing fuel sensors.

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

Space shuttle Endeavour - which itself was scheduled to go up in February and will now be postponed - will most likely have to be repaired as well. The mission STS-123 on space shuttle Endeavour should deliver the pressurized section of the Kibo (Hope) Japanese Experiment Logistics Module (ELM-PS) on the twenty-fifth mission to the International Space Station.