[GioFX]

Atlantis' launch opportunity moves a day earlier

THURSDAY, JULY 27, 2006

Space shuttle program officials today formally changed the opening of Atlantis' launch window to Sunday, August 27 based on projected lighting conditions for photographing the ship's fuel tank. The window had been targeted to open August 28.

NASA has required the first three shuttle flights after Columbia be launched in daylight to allow cameras good visibility for snapping imagery of the redesigned external fuel tanks. The pictures are critical in determining how the tanks' foam insulation perform during ascent.

Engineers recently completed an analysis that showed if the launch occurred August 27 the orbital lighting would be sufficient to photograph the tank in space after its separation from Atlantis.

By moving up the launch a day, the liftoff time actually shifted later in the afternoon -- changing from 4:04 p.m. on August 28 to 4:30 p.m. on August 27.

There will be just 12 days available to launch Atlantis. The usable portion of the daylight window extends through September 7. A liftoff after that isn't believed possible due to scheduling conflicts with the Russian Soyuz mission to ferry the next Expedition resident crew to the space station.

Assuming Atlantis launches by September 3, the Soyuz with Expedition 14 commander Mike Lopez-Alegria, flight engineer Mikhail Tyurin and Japanese space tourist Daisuke Enomoto would blast off at 1:44 a.m. EDT September 14 from Baikonur Cosmodrome, Kazakhstan.

A scenario in which Atlantis' launch is delayed to the final days of the window would result in the Soyuz rescheduling to September 18.

Russian officials want the Soyuz off the ground by September 18 to start the change of command aboard the space station. The departing Expedition 13 crew will return to Earth about 10 days after Expedition 14 is launched, and beginning the handover sequence any later than September 18 would put the homeward-bound capsule's landing in darkness. The Russians are using a recovery team with new personnel and want to avoid nighttime landing activities.

If Atlantis misses the August-September opportunity for some reason, the next window would come at the end of October.

Atlantis has been attached to its fuel tank and boosters inside the Vehicle Assembly Building in preparation for Monday's early morning roll to launch pad 39B. The four-mile trek is set to begin at midnight.

The solar array truss the shuttle will launch to the station was delivered to the pad Wednesday as planned.