Countdown begins for milestone launch

Countdown begins for milestone launch
NASA says Discovery is in ‘excellent shape’ for return to flight
NASA TV image of launchpad and virtual clock
NASA TV
In this image from NASA TV, a virtual countdown clock is superimposed over a view of the shuttle launch pad. The clock shows one day, 18 hours, 56 minutes and 21 seconds. The time is less than the amount of time until the schedule liftoff, because of a series of built-in pauses that halt the countdown.

CAPE CANAVERAL, Fla. - The countdown is under way for the first space shuttle mission in 2 1/2 years — a mission whose main aim is to make sure the problems of the last disastrous shuttle flight can be caught and perhaps corrected.

After fits and starts, NASA says it has changed its hardware and its "safety culture" enough to resume flights after the breakup of the shuttle Columbia on Feb. 1, 2003, which killed all seven astronauts and brought America´s human spaceflight program to a halt.

Investigators say flying foam insulation from Columbia´s external fuel tank knocked out a portion of the orbiter´s left wing just after launch. During re-entry, 16 days later, superheated gases entered through the hole and destroyed the shuttle from within, the investigation concluded.
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"A lot has happened over the last 2½ years", NASA test director Jeff Spaulding told journalists Sunday. "Our focus during that time frame has shifted, from recovery and investigation, to one of redesign and improvement, to mission processing and now to launch."

Discovery´s countdown began at 6 p.m. ET Sunday, starting at T-minus 43 hours. In a sign of changing times, as well as the intense interest in the mission, NASA TV used some electronic tricks to display a countdown from 1:19:00:00 — one day and 19 hours — even though Kennedy Space Center´s Apollo-era outdoor clock is incapable of showing times of more than 24 hours. The virtual clock was superimposed on a view of the launch pad.

If all goes as planned, the countdown will climax with liftoff at 3:51 p.m. ET Wednesday. NASA´s official clock does not match the actual amount of time before the scheduled liftoff because it takes into account a series of built-in pauses, during which time the clock simply freezes.

Spaulding pronounced the shuttle to be in "excellent shape," with weather looming as the biggest uncertainty. Earlier worries about Hurricane Dennis led NASA to bring the shuttle crew in a day early, and at one point launch managers even considered moving Discovery off the pad. But the hurricane made landfall Sunday well to the west, and launch weather officer Kathy Winters said there was a 70 percent chance of favorable conditions for liftoff.

"Our main threat will be inland thunderstorms" that may stir up near the space center, she said.

Winters said prospects for launch could worsen slightly later in the week, partly as a consequence of Dennis´ passage. If Wednesday´s weather is unacceptable, NASA could reschedule the launch for Thursday. After that, the next two backup launch days are Saturday, then Tuesday, Spaulding said.

If Discovery is unable to launch by July 31 due to weather or mechanical problems, the mission would have to be put off until September. That timing is dictated by the requirements for a just-right rendezvous with the international space station, as well as a daytime launch that will make it easy for more than 100 cameras to monitor the shuttle´s ascent to orbit.

Long wait for the crew
It´s already been a long wait for Discovery´s crew of seven, headed by Eileen Collins, NASA´s only experienced woman commander. But former astronaut Rick Hauck, who commanded Discovery in 1988 on the first shuttle mission after the 1986 Challenger explosion, said Collins is as steady as they come.

"I´ve spent a little bit of time with Eileen ... and she is so together, and so ready, and the crew is so ready, that there´s very little advice I could give her," he told MSNBC.com.

But Hauck said he and Collins have discussed how to pay tribute to Columbia´s crew. Although Collins has kept mum about exactly what she and her crewmates will do, Hauck recalled that his crew set aside some time toward the end of the 1988 mission for personal memorials to Challenger.

"Each one of the five of us tailored some remarks," he said, "We each spoke our words."