Shuttle Astronauts Practice Launch Pad Escape

Seven astronauts climbed aboard NASA?s space shuttle Discovery Friday for a vital drill to practice escaping from the spacecraft at the launch pad and go over plans for their late August blast off.

Clad in bright orange pressure suits, the astronauts strapped into Discovery at NASA?s seaside Kennedy Space Center in Florida and rehearsed the last few hours before liftoff before scurrying out the shuttle?s hatch to a set of baskets designed to zip down a 1,200-foot slide wire away from the launch pad in the event of an emergency.

The exercise capped a three-day training session to give Discovery?s astronauts some hands-on experience with the spacecraft before their planned Aug. 25 launch to the International Space Station.

?Everything went really well,? NASA spokesperson Candrea Thomas told SPACE.com from the Florida spaceport.

Commanded by veteran astronaut Rick Sturckow, Discovery?s crew is slated to launch a 13-day mission to the International Space Station to deliver vital supplies, experiments and a treadmill named after comedian Stephen Colbert. Three spacewalks are planned during the mission to replace experiments on the station?s European Columbus lab and install a new ammonia tank for the outpost?s cooling system.

Discovery will also ferry NASA astronaut Nicole Stott to the space station, where she will replace fellow spaceflyer Tim Kopra as a member of the outpost?s six-person crew. Stott joined NASA?s astronaut corps after years working to ready shuttles for flight as an operations engineer at the Kennedy Space Center.

?I?m just thrilled to be able to do it, and I?m looking forward to having it happen,? Stott told reporters of the upcoming flight in a Thursday briefing at the launch pad.

Friday?s launch dress rehearsal and escape drill also made an impression on Discovery astronaut Jose Hernandez, who celebrated his 47th birthday during the training session.

?Great way to spend a b-day!? Hernandez wrote on his Twitter page. Hernandez is one of several astronauts who will be using the microblogging site during the shuttle flight. He is posting updates in English and Spanish.

More work ahead

Before Discovery can launch toward the space station, engineers must close out work to replace a faulty valve on one of the shuttle?s two solid rocket boosters. The valve was replaced this week, with the final clean up work slated to be performed over the weekend, Thomas said.

Engineers are also studying whether modifications will be required for some of the foam-covered ramps on Discovery?s external tank. Some foam debris popped free from similar so-called ice frost ramps when NASA?s shuttle Endeavour launched toward the space station in July. Engineers have been studying the foam loss events to determine what changes, if any, are required for future fuel tanks.

?They're doing some studies and looking into that,? Thomas said. ?Right now we're progressing toward launch.?

Since the ramps in question can?t be reached while Discovery is at the launch pad, if a fix is ultimately required the shuttle would have to return NASA?s cavernous Vehicle Assembly Building, adding a substantial delay to its mission.

Discovery is currently targeted to launch Aug. 25, but could be ready to fly a day earlier if preparations continue to go smoothly and no fuel tank fixes are required. NASA has until the end of August to launch the shuttle mission before it would have to stand down until October due to a flurry of space traffic at the station.

Japan?s first unmanned space cargo ship - the H-2 Transfer Vehicle - is slated to launch toward the station on Sept. 10. Meanwhile, a Russian Soyuz spacecraft carrying two new crewmembers and a Canadian space tourist is also set to launch to the station on Sept. 30.

Discovery would likely have to wait until the completion of both those flights if it cannot launch by month?s end.

The shuttle?s STS-128 mission will mark NASA?s fourth shuttle flight of the year. NASA shuttle officials plan to review Discovery?s flight readiness next week and meet on Aug. 18 to officially select the mission?s launch day.

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