Crawler problems add hours to rollback time
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: August 28, 2006
If rollback is, in fact, ordered, NASA will be in a race against the clock to get Atlantis moved before any thunderstorms develop along Florida's space coast. NASA safety rules forbid moving a shuttle "stack" in winds above 40 knots or if lightning is present within 20 nautical miles.
At the launch pad, a shuttle and its propellant-loaded solid-fuel boosters are protected from the weather by a lightning protection system and rain barriers that effectively surround the orbiter. No such protection is available during a roll to or from the pad.
NASA has not yet committed to hauling Atlantis off pad 39B, but Ernesto's projected track and the prospect of tropical storm- or hurricane-force winds Wednesday could leave the agency with little choice. But a final decision is not required until Tuesday morning, when a crawler-transporter picks up the shuttle's mobile launch platform.
NASA had planned to move Atlantis into high bay 3 in the VAB, which faces the launch pad, after moving another mobile launch platform out of the way. A crawler-transporter moved that MLP out of the bay earlier today, but had to put it back after hydraulic problems developed.
The forecast for Tuesday calls for winds out of the southeast at 8 knots in the morning, increasing to 14 to 20 knots in the afternoon. After 8 p.m., the winds will jump to 17 to 25 knots, still well below the 40-knot limit. There is a 30 percent chance of rain showers in the morning with a 20 percent chance of thunderstorms, a forecast that currently extends to 5 p.m. Tuesday. Between 5 p.m. and 8 p.m., the chance of showers increases to 40 percent with a 30 percent chance of thunderstorms. Between 8 p.m. and 10 p.m., the rain chance goes up to 60 percent with a 40 percent chance of thunderstorms and after 10 p.m., the probability of rain increases to 70 percent with a 60 percent chance of thunderstorms.
"They would like to be moving as soon as they can in the morning so they can be in the barn by eight o'clock," said NASA spokesman George Diller.
If an electrical storm develops during the roll back to the VAB, the safety plan calls for the crawler crew to stop the move and leave the transporter until the storm passes.
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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