NASA on Sunday delayed the launch of the space shuttle Atlantis until January after a gauge in the fuel tank failed for the second time in four days.

The U.S. space agency began fuelling the shuttle around 6 a.m. ET, hoping that the gauges in its big external tank would work properly and allow launch controllers to proceed with an afternoon liftoff.

Shuttle managers said they would halt the countdown and call everything off if any of the four hydrogen fuel gauges acted up.

Three failed during Thursday's launch attempt; no one knows why.

Officials insisted Saturday that all four of the gauges would have to be working on Sunday to move ahead with a launch from the Kennedy Space Center in Florida.

"We're determined to get to the bottom of this," said LeRoy Cain, chairman of the mission management team.

Whether Atlantis can fly as early as Jan. 2 "is all going to depend on what we find out," he said.

The seven-member crew, including one astronaut from France and another from Germany, was set to deliver and install the European-built Columbus laboratory at the International Space Station.