Tank work forces NASA to revise shuttle schedule

Cape Canereal (Fla), Oct 18: NASA this week revised its space shuttle flight schedules for next year due to a slowdown in production of the ships' remodeled external fuel tanks, officials said.

The disposable 154-foot-tall tank has been the focus of the U.S.

space agency's ongoing shuttle safety upgrades since it was pegged as the cause of the 2003 Columbia disaster.

Columbia's tank shed a large piece of its insulating foam during launch that hit and damaged the shuttle's heat shield. The ship broke apart during the plunge through Earth's atmosphere before landing, killing its seven crew members.

''Delivery schedules have always been a factor, but in the past it's just been more behind-the-scenes,'' said June Malone, a spokeswoman at NASA's Marshall Space Flight Center in Huntsville, Alabama yesterday, which oversees the shuttle tank, engine and booster programs.

Now, instead of keeping a stockpile of flight-ready tanks stashed at the shuttle's launch site in Florida, managers are setting schedules around dates when a new tank is due to arrive from the Lockheed Martin-operated manufacturing plant near New Orleans.

Workers were pulled off tank production to handle extensive testing and modifications ordered after the Columbia accident, Malone said.

Damage to the manufacturing plant by Hurricane Katrina in 2005 also contributed to tank production delays, she added.

Fuel tank production is now the pacesetter in NASA's quest to resume routine shuttle service, which is key to completing assembly of the half-built International Space Station.

The 100 billion dollar research outpost, a multinational project led by the United States and Russia, must be assembled before the shuttle fleet is retired in 2010.

First 2007 Launch in March

NASA is on track to fly its third mission of the year in December, but now plans a later start for its five shuttle flights in 2007. Rather than launching shuttle Atlantis with the station's third set of solar arrays on February 22, managers have rescheduled the flight for March 16.

Shuttle Endeavour, which has been out of service since before the Columbia accident for routine maintenance and upgrades, would return to flight on June 28, followed by the launch of the station's long-awaited second connecting node on September 7.

The node marks the arrival of the last major U.S.-built station component and serves as the attachment point for partner laboratories built by Europe and Japan.

The last two missions of 2007, slated for launch on October 17 and December 8, would be devoted to installing the European Space Agency's Columbus research module and the first part of Japan's Kibo complex onto the station.

The shuttle's new flight schedule holds a slot for a possible Hubble Space Telescope servicing mission in April 2008 and two contingency missions to the station to deliver heavy equipment and supplies.

NASA needs at least 14 more flights to the station to finish the complex. Under the new plan, the final flight of the shuttle to the station would be launched on July 9, 2010.

Reuters