NASA on Thursday delayed the flight of the space shuttle Atlantis until late January or, more likely, February to replace a suspect connector in the fuel tank.
The connector is believed to be responsible for back-to-back launch postponements last month.
Deputy shuttle program manager John Shannon said the mission to the international space station is off until at least Jan. 24. “Everything has to go exactly right for us to make the 24th,” he said.
Shannon said it’s more likely that Atlantis won't be ready to lift off until Feb. 2, or Feb. 7 if managers decide to conduct another fueling test. However, the Russians are currently scheduled to send a Progress cargo ship to the space station on Feb. 7, and that could pose a conflict.
"Today our rules say we won't dock a Progress if we have a shuttle docked there," NASA's space station program manager, Michael Suffredini, told reporters.
If the shuttle actually launches in the Jan. 24-26 time frame, the Progress would likely launch as scheduled, Suffredini told reporters. Another scenario could call for the Russians to delay their launch for a couple of days. But if prospects for launching the shuttle are still "real fluid" in late January, NASA would likely hold off on Atlantis' liftoff until after the Progress docking.
One thing is certain: The flight scheduled after Atlantis, Endeavour's mission to bring the first component of Japan's space lab to the station, won't begin on Feb. 14 as originally scheduled. NASA's rule of thumb is to leave at least five weeks between shuttle launches, which would put off Endeavour's launch until no earlier than late February.
Shannon said the picture should become clearer in "the next week to 10 days," after tests have been conducted on some modified parts for Atlantis' fuel tank.
Atlantis was poised to lift off in early December with a European space station lab named Columbus, but fuel gauges in the external fuel tank failed late in the countdown.
The problem cropped up again during a second launch attempt, prompting NASA to conduct a fueling test just before Christmas. That's when the trouble was traced to a connector that feeds circuitry through the wall of the fuel tank. The circuitry runs between the fuel gauges in the bottom of the tank and the space shuttle.
The fuel gauges are part of a critical safety system to prevent the shuttle’s main engines from running on an empty tank, and have malfunctioned off and on for more than two years. Engineers suspect a design issue.
NASA removed the external portion of the suspect connector, along with some plugs, over the weekend. It will be another two weeks before the parts are fully analyzed, mimicking the super-cold conditions of fueling, Shannon said.
In the meantime, engineers will replace the external connector and make some modifications — essentially soldering pins and changing the material of socket inserts.
“What we’re doing ... is addressing what we think is the most probable cause, and there’s a lot of information that points to that connector and that this is the right design fix,” Shannon said.
Shannon said that Atlantis' crew was taking the delay in stride. Just this week, he said, he saw shuttle commander Steve Frick "all suited up and ready to fly out" to El Paso and NASA's White Sands Space Harbor for landing practice.
"From all I can tell, [he's] very excited and ready to go whenever the shuttle is," Shannon said.
Until a firm launch date is set for Atlantis, NASA will not address the timing of subsequent flights, Shannon said.
NASA faces a 2010 deadline for retiring its three shuttles and completing the space station.
This report includes information from The Associated Press and msnbc.com.