NASA will not launch space shuttle Atlantis on Tuesday as Tropical Storm Ernesto threatens Florida, the space agency said Monday morning.
NASA said it will immediately begin preparations to move Atlantis from the launch pad, Dean Acosta, NASA press secretary, said.
Ernesto weakened to a tropical storm Sunday afternoon, the National Hurricane Center said, but forecasters warned the storm could regain hurricane status as it moved toward Cuba.
NASA is dealing with a tight time frame for Atlantis. The launch window is from August 27 through September 13. But NASA has a commitment to the Russian space agency to launch before September 7, so the Atlantis mission will not interfere with a scheduled Russian Soyuz flight to the space station in mid-September.
Meanwhile, the six-member crew of this shuttle mission is resting and relaxing in their quarters. Commander Brent Jett and pilot Chris Ferguson flew on the shuttle training aircraft Sunday morning, and the crew could get some time with family on Monday.
NASA hurricane guidelines call for the shuttle to be moved off of the launch pad if peak winds are forecast to reach 70 knots (79 mph). It must be moved to the assembly building before winds reach 40 knots (46 mph) and with no lightning within 20 nautical miles.
Ernesto is just one of the weather problems NASA has been dealing with over the past few days. But the other, related to a lightning strike Friday afternoon, has been resolved.
"We have been able to clear the vehicle with respect to lightning strikes," said LeRoy Cain, NASA's launch integration manager. "That is very good news for us."
Atlantis had been scheduled to launch on Sunday afternoon, but was delayed after lightning hit the launch site during a thunderstorm Friday afternoon. It was the strongest strike ever recorded at the launch site.
NASA officials had earlier cleared the orbiter and the external fuel tank of any lightning-related problems. At a Mission Management Team briefing Sunday night, Cain cleared the final questions related to the solid rocket boosters.
This Atlantis flight is being called "return to assembly." It is the first shuttle mission since the crash of Columbia in 2003 to deliver a major new portion of the International Space Station.
Once docked with space station, astronauts will conduct three spacewalks to install a second set of solar arrays to the station. That should double the station's power capability, and add more than 17 tons to its mass. The solar arrays have been packed away since May 2003, when they were originally scheduled to be delivered to the station.