A one-minute launch window for space shuttle Atlantis was closed Sunday after NASA technicians discovered a malfunctioning sensor.
The faulty sensor was discovered while the shuttle was being fueled Sunday morning. The launch cancellation was announced on NASA TV at 7:24 a.m. ET.
NASA subsequently made the decision to scrap any further launch attempts until January.
Atlantis and its seven-person crew first intended to launch Thursday. The attempt was scrapped when two of four gauges in its hydrogen tank failed as it was filled for liftoff.
A third sensor later acted up, prompting NASA managers to investigate the problem and impose strict rules on today's launch.
NASA representative Steve Roy told Â鶹´«Ã½net on Sunday that safety measures imposed after Thursday's launch was canceled led to today's decision.
"Launch criteria this morning did include having all four of those censors providing accurate information, and one of them failed," he said. "We've decided not to go forward with our plans to launch the space shuttle this afternoon."
Roy said NASA has had problems with faulty fuel gauges for about two-and-a-half years. While the cause of the problems is unknown, it is believed to be a wiring issue, he said.
"If I knew the answer to that question I'd be the most popular person here on the launch centre this morning," he said.
They will continue filling the fuel tank in order to "troubleshoot" for the next launch, Roy said.
NASA officials said Saturday the countdown would proceed only if all four gauges were working properly.
They also narrowed the launch window from five minutes to one minute to put Atlantis on a more precise path to the space station and limit fuel consumption in case of sensor trouble after launch.
"We are approaching this in a very cautious manner," shuttle program manager Wayne Hale told the Associated Press on Saturday. "Now could something bad happen in spite of all our caution? Yes. This is a risky business."
NASA officials have said that Atlantis would have had an opportunity to launch at 3:21 p.m. ET Sunday from NASA's Kennedy Space Center in Florida.
Shuttle commander Stephen Frick and his crew are to deliver and install Columbus, a European science lab, at the International Space Station.
Columbus would be the second scientific laboratory to be added to the International Space Station, following the Destiny lab brought up in 2001.
Japan's huge lab, Kibo, will be sent up to the ISS in three sections starting in February.
