Countdown clocks start ticking for Friday's launch
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: May 11, 2010
The countdown began Tuesday for launch of the shuttle Atlantis Friday on its 32nd and final planned mission, a 12-day three-spacewalk flight to deliver a Russian module and fresh solar array batteries to the International Space Station.
The countdown began on time at 4 p.m. EDT, setting the stage for a launch attempt at 2:20:08 p.m. Friday, roughly the moment Earth's rotation carries launch pad 39A into the plane of the space station's orbit.
"We are ready to launch," Ham said from the shuttle runway. "We've completed every bit of training we can and we're confident. We appreciate all the hard work from the (Atlantis) team down here, they've done an amazing job getting the vehicle turned around, on the pad and ready to go. From absolutely every report I've read, the airplane, the spaceship is ready to go. And we're ready to fly! So look for a good show on Friday."
Forecasters are predicting a 70 percent chance of acceptable weather, with the major concern being a chance of low clouds. The forecast remains 70 percent "go" through the weekend.
"Weather is looking favorable for launch," said Kathy Winters, a shuttle forecaster. "Right now, we have a high pressure area to our northeast and an easterly flow over the area. It's a little breezy today, but the winds are going to come down over the next few days and that's going to allow us to have favorable weather for launch.
"Our only concern is sometimes when we get in this pattern we get these convergent bands of clouds and those can sometimes come over the area and cause a low-cloud ceiling. So that's our primary concern."
Going into the countdown, NASA Test Director Steve Payne said processing has gone smoothly and "our vehicle systems are in great shape."
"Atlantis, her crew and the launch team are ready to go," Payne said. "We're looking forward to a beautiful launch on Friday afternoon."
If all goes well, engineers will pump a half-million gallons of liquid oxygen and hydrogen rocket fuel into Atlantis' external tank starting at 4:55 a.m. Friday. The procedure should be complete by around 8 a.m., clearing the way for Ham and his crewmates to begin strapping in around 11 a.m.
The current launch window extends through May 18 and NASA managers say they can make four launch attempts in five days. If the shuttle is not off the ground by then, the flight would slip to June 29 because of conflicts with an upcoming Delta launch, a Russian space station mission and because of temperature constraints related to the station's orbit.
This will be the 32nd and last planned mission for Atlantis as NASA works through a final three missions before retiring the shuttle fleet. The shuttle Discovery is scheduled for launch in September, followed by a flight by Endeavour in late November or early December.
But Atlantis will be processed for launch on a possible rescue mission in case of major problems that might prevent Endeavour's crew from returning to Earth. And NASA has not ruled out the possibility of actually launching Atlantis on a station resupply mission, using the last available external tank and booster set. With a reduced crew of four, a launch-on-need shuttle mission would not be required. But no such decisions have been made.
While it's not yet clear whether the current mission is, in fact, Atlantis' last, Payne said no special events have been planned to mark the occasion.
"Everybody realizes there's a lot of history going on here and that they're part of it and they're living it," Payne said. "So we're making a point of savoring the moment while we can, because this has really been a privilege for us to work out here and be associated with this program."
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