Atlantis sits on the launch pad

The U.S. space agency, NASA, says the launch of the space shuttle Atlantis could happen in late January or early February.

Deputy shuttle program manager John Shannon told reporters Thursday during a conference call that everything would have to "go exactly right" to meet the earliest possible launch date of January 24.

Shannon added that a February lift-off is more likely.

The launch of Atlantis was delayed twice in December due to faulty sensors in the shuttle's external fuel tank. Shannon said engineers now believe the problem lies with a connector in the tank.

The next mission is meant to transport a European space laboratory, named Columbus, to the International Space Station.

NASA is on deadline to finish construction of the space station before the shuttles are retired in 2010.

Previous missions attached Russian- and U.S.-made laboratories. A Japanese lab, the Kibo, is scheduled for delivery to the station later this year.