Weather Outlook Improves for Friday Shuttle Launch

CAPE CANAVERAL, Fla. -- The weather forecast for Friday?s evening liftoff of the shuttle Atlantis has improved and NASA officials are optimistic launch will take place as planned.

?After many months of hard work, Atlantis is nearly ready to fly,? said NASA test director Steve Payne Thursday in a mission briefing here at the Kennedy Space Center (KSC) spaceport. ?We are currently tracking no significant issues on the vehicle.?

Dark, heavy clouds poured rain and spouted lightning around KSC Wednesday evening, but the shuttle launch facility was spared the brunt of the storm?s fury.

Instead, most of the rain and even three-quarters inch hail fell some 50 miles (80 kilometers) south of KSC.

?We did have some significant weather in the area last night, but luckily, most of it came together in Melbourne, as opposed to up here over the launch pad,? said NASA shuttle weather officer Kathy Winters.

Forecasters predict favorable weather conditions for Friday evening, when Atlantis is slated to loft into space at 7:38 pm EDT (2338 GMT) with the seven STS-117 astronauts. Atlantis' astronaut crew, commanded by veteran spaceflyer Rick Sturckow, is tasked with delivering and installing two new truss segments and a pair of starboard solar arrays at the International Space Station (ISS).

The current forecast gives an 80 percent chance that Atlantis will launch on time?up from 70 percent yesterday. Favorable weather is also predicted for NASA?s contingency landing sites in the U.S. and Europe, Winters said.

In case of a delay, the weather forecast for Saturday and Sunday drop to 70 and 60 percent chance ?Go,? respectively.

?Overall, the first day is the best day for the overseas site and the U.S. site and also Kennedy Space Center,? Winters said.

Atlantis has an open launch window from June 8 to 12, after which it will have to stand down for four days to make room for a planned rocket launch on June 14. The window reopens on June 17 and runs through mid-July.

The shuttle was originally slated to fly on March 15, but was delayed when a freak thunderstorm peppered the Atlantis' foam-covered external tank with hail, leaving thousands of defects that had to be repaired.

?We have complete confidence in our repair technique, and we expect it to perform, as did STS-96? when Atlantis had to be similarly repaired, said Rob Worthy, NASA vehicle manager for Atlantis' fuel tank and solid rocket boosters. ?We feel that we are safe and ready to fly.?

Today, the STS-117 astronauts are scheduled to accompany their friends and family on special guest tours of KSC, as well as sit on a series of briefings related to launch and practice shuttle landing in a modified Shuttle Training Aircraft (STA).

The first of four scheduled holds in the launch countdown will commence at 1:00 p.m. EDT (1700 GMT) today, and will last for four hours. The rotating service structure that protects the shuttle is expected to be retracted later tonight, and fueling for launch is scheduled for tomorrow morning.

• SPACE.com Video Interplayer: Space Station Power Up with STS-117
• STS-117 Power Play: Atlantis Shuttle Crew to Deliver ISS Solar Wings
• The Great Space Quiz: Space Shuttle Countdown
• Complete Shuttle Mission Coverage