Hail Storm Grounds Shuttle
02/28/2007
CAPE CANAVERAL, Florida (AP) -- Hail from a fast-moving thunderstorm dinged a section of space shuttle Atlantis' external fuel tank as it sat on the launch pad, putting next month's launch in jeopardy.
NASA managers met Tuesday to determine if the damage was severe enough to postpone the March 15 launch. The storm left hundreds of divots on the fuel tank, hit protective tiles on the shuttle's wing and damaged a training jet parked at the Kennedy Space Center.
"Right now, the big deal is how many divots? How deep are they? Can they be repaired at the pad? Can they not be repaired at the pad?" NASA spokesman Bill Johnson said.
The need to make repairs raised the likelihood that the launch would be delayed since NASA only has four extra days to spare in its launch-preparation schedule.
NASA managers weighed the options of making repairs to the external tank on the launch pad using an enormous crane or moving the space shuttle back into its Vehicle Assembly Building to fix the divots. NASA also has another external fuel tank at Kennedy Space Center that is being readied for a mission in June.
The damage was concentrated in the upper third of the 153-foot-tall external tank, a section which holds liquid oxygen propellant.
The shuttle's launch window ends around March 25 in order to allow Russia to launch a Soyuz vehicle to the international space station in early April.
Monday evening's thunderstorms moved quickly and had winds of up to 60 miles (96 kilometers) per hour. The size of the hail was between a half inch and two inches (1 and 5 centimeters) and landed only at the NASA space center. The National Weather Service considers three-quarters-of-an-inch-sized hail to be "severe," said David Sharp, a meteorologist with the weather service.
"Most people didn't see thunderstorms, let alone severe thunderstorms," Sharp said. "It only occured in one location, and that was NASA's Kennedy Space Center complex."
In 1999, hail from a storm made 650 divots in space shuttle Discovery's external tank, forcing NASA to delay a launch and return the spacecraft to the Vehicle Assembly Building. In 1995, space shuttle Discovery was sent back to the Vehicle Assembly Building because of fuel-tank damage caused by a pair of woodpeckers that drilled about 200 holes in the rust-colored foam insulation, apparently in an attempt to roost and build nests.
Hail also hit the external tank of space shuttle Atlantis in 1990, causing minor damage.
The insulating foam on the external tank is of special concern to NASA since foam flew off space shuttle Columbia during lift off in 2003 and struck the orbiter. The damage allowed fiery gases to penetrate Columbia during re-entry, breaking up the craft and killing its seven astronauts.
NASA redesigned the external tank, removing large amounts of foam, before last year's three successful shuttle missions. The space agency plans another design change to the tank before the shuttle program ends in 2010.
During their 11 days in space, Atlantis' astronauts are scheduled to deliver a 35,000-pound (15,875-kilogram) addition, the heaviest ever, along with a new pair of solar arrays. Crew members will unfurl the solar arrays, fold up an old pair and conduct at least three spacewalks.