Weather May Delay Shuttle Launch Again

As Tropical Storm Nears, NASA Officials to Decide Today Whether to Proceed

CAPE CANAVERAL, Aug. 27 -- Caught between a worrisome weather forecast and their need to launch the long-delayed space shuttle Atlantis mission, NASA officials will decide early Monday morning whether to proceed with their countdown or to roll the shuttle back into its protective hangar.

NASA officials were pessimistic Sunday night about their chances for a launch this week but said they wanted to allow Tropical Storm Ernesto a little more time to change course. Current projections bring the storm to the Kennedy Space Center by midweek, and officials said they could not risk leaving Atlantis on its launchpad if the forecast doesn't improve.

The launch has already been delayed by two days because of stormy weather and concerns that a Friday lightning strike might have damaged the vehicle. But after several days of testing for damage, NASA concluded Sunday that the shuttle is in good flying condition.

LeRoy Cain, a senior shuttle manager, said that although NASA plans to make a go/no-go decision Monday morning, the team has until noon Tuesday to rescind a decision to scrub the flight. He said that if the weather forecast then changed substantially, Atlantis could be launched later in its 12-day launch window, which will end Sept. 7.

Michael T. Suffredini, NASA's international space station project manager, held out the possibility that the Russian space agency would reschedule a planned mid-September trip to the space station to make room for a more significantly delayed Atlantis mission. If the Russians cannot delay their flight, officials said, NASA would have only three or four possible launch days the rest of the year.

Any substantial delay in the Atlantis mission would be a blow to concerted efforts underway to complete the long-delayed space station by 2010.

"This flight has to work for the next flight to occur, and then for the next after that," Suffredini said. "This one is key."

The reason is the 17-ton truss and solar energy system that Atlantis will hoist up to the station -- equipment needed before astronauts can even prepare to do many of the zero-gravity experiments the station was designed to make possible. The huge solar power grid that the shuttle will deliver must be in place and operating before two other large Japanese and European space labs can be ferried up, attached and put to work.

Only the U.S. space shuttles can deliver payloads as large as the trusses, and the shuttles either have been grounded or have been on largely safety-monitoring missions since the 2003 Columbia disaster.

Sunday was an especially hectic day at the Kennedy Space Center. Some ground crew members continued to prepare for a Tuesday liftoff; others began the process of disconnecting systems for a possible rollback. The huge "crawlers" that would pull the shuttle back to its safe haven were also tested throughout the day.

Cain said that launches have had to be scrubbed only four times because of hurricanes and tropical storms. By regulation, the shuttle is supposed to be stored safely in a hangar whenever winds of 45 mph or higher are forecast.

The area around Cape Canaveral is subject not only to late-summer hurricanes but also to lightning strikes, which have earned it the distinction of being part of Florida's "lightning alley."

The lightning that hit the launchpad on Friday did not strike Atlantis but was strong enough to create an electrical field around the shuttle.