Likely Looking At February Now

NASA determined Thursday the shuttle Atlantis will not fly until later this month, at the very earliest -- and, more likely, won't liftoff until sometime in February -- as the agency works to solve a persistent issue with fuel sensors inside the external fuel tank.

As ANN reported, Atlantis was scheduled to liftoff in early December on the latest construction mission to the International Space Station, but a malfunction in two of the four engine cut-off sensors inside the tank scrapped the launch -- as well as a second attempt four days later.

The sensors detect the level of liquid hydrogen in the fuel tank, to determine when to shut down the shuttle's three main engines. Failure of the sensors could shut the engines down too early, or, conversely, run them dry -- the latter a catastrophic scenario. An on-pad test of the fuel system revealed the likely cause of the glitch -- a connector that feeds wiring through the skin of the external tank, and mates up with the orbiter.

Last weekend, engineers removed the external portion of the connector -- but it will be two weeks before the parts are completely analyzed, Deputy shuttle program manager John Shannon told The Associated Press. In the meantime, NASA will replace the suspect part with a new one -- though engineers suspect the design of the connector is at fault, and the cause of similar problems over the past several years.

For the moment, NASA is holding out hope for a January 24 launch for Atlantis... but that's the best-case scenario.

"Everything has to go exactly right for us to make the 24th," Shannon said. "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 did not give a timeframe on how long the delay could last, if the quick-fix solution doesn't solve the problem. He would also not give an estimate on future shuttle launches -- though the delay to Atlantis means the scheduled February 14 launch of Endeavour won't occur as planned, either, since the agency requires at least five weeks between launches.

The deadline for the completion of the shuttle program -- as mandated by the White House -- is September 30, 2010... a date that looms large on NASA calendars, with less that two years to go to complete 11 remaining missions.

FMI: www.nasa.gov/mission_pages/shuttle/main/index.html