Storm Puts Launch Date on the Bubble

The space shuttle Atlantis was caught between storms Sunday that made it increasingly unlikely that the shuttle will be able to launch this week.

The latest problem for the shuttle, which suffered a major lightning strike from a storm Friday, occurred when Tropical Storm Ernesto turned away from the Gulf Coast. As of late Sunday, it was heading east on a track that could carry it over the central Florida launch facilities later this week.

NASA managers, scrambling to save the mission, temporarily slipped the launch date one more day, to Tuesday. But with the approach of bad weather, managers were scheduled to decide this morning whether to begin preparing Atlantis for rollback into the giant Vehicle Assembly Building, where it could safely ride out the storm.

The rollback process takes two days but could still be halted in time for a Tuesday launch, if Ernesto veers away. But experienced weather watchers at NASA said that appeared unlikely.

“This looks like a storm that is fairly predictable,” said the launch director, Mike Leinbach. “Something unusual would have to happen for us not to start rollback preparations tomorrow.”

Rollback requires workers to un-mate the orbiter, its twin solid rocket boosters and its external fuel tank from the launch platform. Then, the 4.5-million-pound shuttle is loaded onto a giant crawler for the slow ride back to the assembly building.

Rollbacks because of bad weather are unusual, even in storm-ridden Florida. There have been four previous rollbacks, three of them in 1995 and 1996.

One bit of good news Sunday was the announcement that NASA engineers were no longer concerned that Friday’s lightning strike might have damaged the orbiter. Measuring 100,000 amps, the largest strike ever recorded at the launchpad, it hit the lightning mast above the shuttle. After the strike, some instruments on the orbiter and at the pad produced questionable readings.

Engineers were particularly concerned that an electrical bus in the orbiter and the pyrotechnic devices that separate the solid rocket boosters from the orbiter after launch might have been fried. As it turned out, the lightning mast did its job.

“We’ve been able to clear the vehicle from the concerns over the lightning strike,” said LeRoy E. Cain, chairman of the Mission Management Team, which has final authority over launch decisions.

But that news was tempered by the growing concern over the approach of a new storm.

Weather restrictions call for a launch postponement when winds rise to 40 knots. Caleb Nordgren, a Navy weather forecaster, said those winds were likely to hit the cape as early as Wednesday afternoon.

Even though that appeared to give Atlantis a launch opening Tuesday afternoon, taking a shuttle from the pad is a slow process, and nobody wants to have it sitting out in a hurricane.

Ernesto has been downgraded to a tropical storm, but weather officials said it could become a hurricane again when it passed over Cuba and into warm waters.

Once rollback preparations begin, it becomes increasingly difficult to return to launch mode.

Conceivably, Atlantis could be returned to its hangar for the storm and then return to the launchpad. But it takes about a week to get the vehicle ready for a launch once it’s back in the assembly building.

A further problem is that though the current launch window extends into mid-September, Atlantis could be facing a traffic jam at the International Space Station.

The Russians are scheduled to send another mission to the station next month.

Only one vehicle can dock at the station at a time.

NASA officials were planning to confer overnight with the Russians to work out a plan of action if Atlantis was further delayed.

The next launch window opens in late October.