Weather Outlook Iffy For Launch

The weather outlook has deteriorated slightly for launch of the shuttle Atlantis on Sunday. The NASA range weather officer puts the odds at about 60% for a launch, down from 70%. Concerns are for electrical storms in the area.

CAPE CANAVERAL, Fla. - NASA's chances of launching the shuttle Atlantis toward the International Space Station (ISS) Sunday have dropped slightly due to impending thunderstorms, weather officials said Friday.

Shuttle weather officer Kathy Winters said Atlantis now has a 60 percent chance of rocketing spaceward at 4:29:57 p.m. EDT (2029:57 GMT) Sunday, down from 70 percent Thursday, because of stormy weather and thick clouds expected during the spacecraft's countdown.

"We'll probably go red during the countdown," Winters said, referring the weather status near Atlantis' Pad 39B launch site.

The main concern for launch involves anvil clouds, electrically charged clouds associated with thunderstorms, could be within 20 nautical miles (37 kilometers), of the Kennedy Space Center (KSC). The clouds could spawn lightning during shuttle flight and must be clear of NASA's Shuttle Landing Facility should Atlantis be forced to make an emergency landing.

Weather willing, Atlantis' STS-115 astronaut crew will carry a new pair of solar arrays and a 17.5-ton set of trusses to be installed on the port side of the ISS.

As of right now, the countdown clock is still running normally, with 1 day, 2:34 hours left. They have a picture up of a lightning strike on the launch pad last night as well.

UPDATE: Launch has been pushed back 24 hours partly because of that lightning strike.