Ernesto forces shuttle Atlantis off the launch pad
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: August 29, 2006
With tropical storm Ernesto threatening Florida, NASA managers today reluctantly ordered engineers to proceed with plans to move the shuttle Atlantis back to the protection of the Vehicle Assembly Building, a move that likely will delay the flight to late October.
By keeping Atlantis at the pad, NASA could, in theory, be ready for launch by Sunday or Monday assuming the storm caused no major damage. But with forecasters predicting 50-knot winds Wednesday with gusts to 65 knots, Leinbach and other senior managers decided to err on the side of caution.
Engineers operating a powerful crawler-transporter then jacked up Atlantis' mobile launch platform and began the slow trip to the VAB at 10:04 a.m.
The 4.2-mile trip from the launch pad to high bay 2 on the west side of the Vehicle Assembly Building was expected to take about 10 hours to complete. That's two hours faster than originally expected because of a decision to run the crawler at its top speed of 1 mph when possible. But the average speed will be less.
The slow speed is not surprising given the enormous mass of the shuttle and its mobile launch platform. The two-story MLP, which measures 160 feet by 135 feet, weighs 9.25 million pounds. With an unfueled space shuttle attached, the weight climbs to 12 million pounds.
The original plan called for moving Atlantis to high bay 3 on the east side of the VAB closest to the launch pad. That would have reduced the travel time to about eight hours. But problems with NASA's only other crawler prevented engineers from moving another MLP out of the way Monday. As a result, Atlantis will have to make a longer trip to the far side of the VAB.
The forecast for today's move calls for an increasing chance of showers as the day wears on with the odds of thunderstorms climbing to 30 percent between 5 p.m. and 8 p.m. Between 8 p.m. and 10 p.m., there's a 40 percent chance of thunderstorms, 60 percent between 10 p.m. and midnight.
At the launch pad, the shuttle is shielded by a very effective lightning protection system. A 100,000-amp lightning strike at the pad last Friday caused no major damage. But during the roll back to the VAB, the shuttle is exposed to the elements and NASA hopes to avoid thunderstorms if at all possible.
Today's decision to roll the shuttle back to the VAB was a critical milestone for NASA because it all but eliminates any chance of launching before the Sept. 7 end of the shuttle's current launch window.
The end of the launch window is defined by NASA's desire to launch in daylight for photo documentation of the shuttle's heat shield and external tank and by Russian plans to launch a Soyuz rocket by Sept. 18 to deliver a fresh crew to the international space station.
Based on lighting alone, Atlantis could launch as late as Sept. 13. NASA would need at least eight days to ready the shuttle for flight after a roll back out to the launch pad after Ernesto passes and if lighting alone was the limiting factor, at least a few launch attempts would be possible.
But any launch past Sept. 7 would force the Russians to delay the Soyuz beyond Sept. 18, resulting in a dead-of-night landing for the space station's outgoing crew. The Soyuz recovery team is operating under new civilian management for the first time and so far, Russian space managers, citing flight safety, have refused to move the launch date past the 18th.
If that holds up, NASA will be forced to delay Atlantis' launch on a long-awaited space station assembly mission until a two-day window that opens Oct. 26. The next lighted window after that is a one-day opportunity Dec. 23.
NASA managers already are discussing ways to expand the October window slightly, by either relaxing some of the lighting requirements or changing station operations to loosen temperature constraints.
As it now stands, a launch by Atlantis in October almost certainly would delay a planned Dec. 14 flight by the shuttle Discovery to mid January. That, in turn, would delay three critical post shuttle-undocking spacewalks by the station crew to February in a ripple effect that could have implications for other downstream flights.
But in the near term, Ernesto is the center of NASA's focus as engineers haul Atlantis back to the VAB and prepare the launch pad and other facilities for tropical storm-force winds Wednesday.
The official crew patch for the STS-115 mission of space shuttle Atlantis to resume orbital construction of the International Space Station.
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