Shuttle Launch Date Slips as NASA Tackles Sensor Fix

Shuttle Launch Date Slips as NASA Tackles Sensor Fix
In the late afternoon shadows, space shuttle Atlantis is still poised on the pad after its launch on mission STS-122 was postponed. The mission was rescheduled to no earlier than January 2008. (Image credit: NASA/George Shelton.)

NASA'slaunch of the space shuttle Atlantis has slipped to late January, with a pushto early February likely, as engineers work to replace a faulty fuel tankconnector, a top official said Thursday.

JohnShannon, NASA's deputy shuttle program manager, said Atlantis will not flyuntil Jan. 24 at the earliest, a two-week slip from an earlierJan. 10 target, to allow tests and modifications of a vital fuel tankconnector.

"Everythinghas to go exactly right for us to make the 24th," Shannon told reporters.

More likelylaunch targets are Feb. 2 or Feb. 7, which allows time for extra tests but nomajor unexpected surprises, Shannon said.

Atlantis'planned 11-day mission to deliver a new Europeanlaboratory to the International Space Station (ISS) has been delayedsince early December, when vital fuel gauge-like sensors failed standardcountdown checks. Known as engine cutoff sensors, the fuel gauges serve as abackup system to shutdown an orbiter's three main engines before its fuelsupply runs out.

NASAtracked the glitch to a suspectelectrical connector near the bottom of Atlantis' 15-story external tank,where sporadic open circuits may form as the tank is filled with its super-coldliquid hydrogen propellant.

Thethree-part connector consists of an interior electrical socket, a glass-and-metalpin bridge and an exterior electrical socket that work together to transmit signalsfrom four liquid hydrogen fuel gauges to a computer aboard Atlantis.

Engineershave already removed exterior portions of the electrical connector and willreplace it next week with a modified version with wires soldered directly totheir corresponding pins to avoid open circuits, NASA said.

"It'sfairly simple," said Shannon. "It's a fairly elegant change and wefeel very confident that, if the problem is where we think it is?that this willsolve that."

NASArequires at least a five-week breather between shuttle launches, which pushesthe planned Feb. 14 launch of the Endeavour orbiter and the first part of Japan's massive Kibolaboratory beyond its initial target, he added.

The spaceagency also must not conflict with the planned ISS arrival of the unmannedRussian Progress 28 cargo ship, which is currently slated to launch on Feb. 7.

"The hardconstraint today is not to have a shuttle docked while we're trying to dock aProgress," said Mike Suffredini, NASA's ISS program manager.

Suffrediniadded that ISS managers are also discussing when to add an extra spacewalk tothe chore list of the space station's Expedition 16 crew to replace a solar wingmotor.

Commanded byveteran spaceflyer Stephen Frick, Atlantis' seven astronauts expect to installthe European Space Agency's Columbus laboratory and stage at least threespacewalks slated for their shuttle mission.

"Theydid get the holidays off. I think that was a good thing," Shannon said ofthe shuttle astronauts. "They're, from all I can tell, very excited andready to go whenever the shuttle is."

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Tariq Malik

Tariq is the Editor-in-Chief of and joined the team in 2001, first as an intern and staff writer, and later as an editor. He covers human spaceflight, exploration and space science, as well as skywatching and entertainment. He became's Managing Editor in 2009 and Editor-in-Chief in 2019. Before joining, Tariq was a staff reporter for The Los Angeles Times covering education and city beats in La Habra, Fullerton and Huntington Beach. In October 2022, Tariq received the Harry Kolcum Award for excellence in space reporting from the National Space Club Florida Committee. He is also an Eagle Scout (yes, he has the Space Exploration merit badge) and went to Space Camp four times as a kid and a fifth time as an adult. He has journalism degrees from the University of Southern California and New York University. You can find Tariq at and as the co-host to the This Week In Space podcast with space historian Rod Pyle on the TWiT network. To see his latest project, you can follow Tariq on Twitter @tariqjmalik.