NASA halts shuttle flights over tank foam problem
Wed Jul 27, 2005 8:54 PM ET
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By Irene Klotz

HOUSTON (Reuters) - NASA grounded its space shuttle fleet on Wednesday after learning that large chunks of insulating foam broke off Discovery's external fuel tank during launch, an echo of the problem that doomed sister ship Columbia and its crew 2 1/2 years ago.

The seven Discovery astronauts were not in danger and the falling debris does not appear to have hit or damaged their ship, which took off on Tuesday on a 12-day mission to the International Space Station, deputy shuttle program manager Wayne Hale said.

But NASA said it would launch no more shuttles until it resolves the recurring problem of debris falling off during blastoff.

"Until we fix this, we're not ready to go fly again," shuttle program manager Bill Parsons said. "I don't know how long that is right now. We have a lot of work in front of us to figure that out and we're going to go do that."

Images of the shuttle's tank, which was jettisoned as planned just before Discovery slipped into orbit, show at least three areas where large chunks of insulation foam came off, Hale and Parsons said.

The finding was troubling because a 1.67-pound (0.75-kg) piece of foam insulation broke off Columbia's external tank during its launch on Jan. 16, 2003, and gouged a hole in the ship's wing.

As Columbia attempted to fly through the Earth's atmosphere for landing 16 days later, superheated gases blasted into the

Still image released by NASA July 27, 2005 and taken by Discovery's crew, shows the external fuel tank as it was jettisoned after its launch on July 26. NASA halted future shuttle flights on Wednesday after learning that a large chunk of insulating foam broke off Discovery's external fuel tank during launch, an echo of the problem that doomed sister ship Columbia and its crew 2-1/2 years ago. In this image, the area of missing foam on the tank is indicated by a light spot centered just below the liquid oxygen feedline.

 breach and tore the ship apart, killing the seven astronauts on board.

NASA has since spent more than $1 billion improving the tank and adding other safety upgrades. Discovery's flight was the space agency's first manned mission since the Columbia accident and was to be the first of two to test the new gear.

"We thought we were safe to fly as is," Parsons said. "Obviously we were wrong."

The largest of the three missing chunks of foam was about the same size as the one that hit Columbia, but "the video clearly shows that it fell away and did not strike the orbiter," Parsons said.

Engineers were also looking at two areas on the shuttle's belly where pieces of the ship's heat-resistant tile were missing

Discovery Launch Gallery

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bird STS-114_birdhit STS114 Tile Event STS114-debris
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Superheated gas in the Arc Jet machine blasts the material used in the repair kit provided for the space shuttle Discovery.
Cesar Acosta / NASA Ames Research Center
Superheated gas in the Arc Jet machine blasts the material used in the repair kit provided for the space shuttle Discovery.
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Shuttle now carries 'repair kit'


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For space shuttle astronauts, computer crashes and broken gyroscopes during flight have long been fixable glitches.

Now, on the Discovery flight, set to lift off as soon as this week, the crew will -- for the first time -- have a sturdy repair kit handy to plug holes in case the spacecraft's wings are punctured in transit.

Engineers at NASA/Ames Research Center gave the kits a rigorous workout, using a superheated tube called an Arc Jet to see if these patches can take the heat. Loose insulating foam that detached and pierced a hole in space shuttle Columbia's left wing caused the Feb. 1, 2003, disaster in which seven astronauts died. NASA experts say this could help fix a similar problem should it happen again.

``If you have a flat tire, you have a spare,'' Ernie Fretter, a mechanical engineer involved in the tests, said last week in the Arc Jet workshop. Before, if the shuttle hit a snag, crew members would be stuck or have to be rescued at the space station. ``You can't stuff space suits in the hole.''

The Arc Jet team's engineers and computer scientists are among 100 people at Ames who will be on call to help if something goes wrong with Discovery's mission. It is the first time since the National Aeronautics and Space Administration began launching space shuttles that Ames workers have been on deck to help during a flight, NASA officials say.

Other Ames employees will be running supercomputer simulations of the launch and also checking results of shuttle's aerodynamic behavior in the wind tunnel to see how parts operate in flight.

Discovery's launch, the first return to orbit since the Columbia disaster, has been delayed due to a fuel gauge malfunction.

Fretter said the Arc Jet engineers are thrilled to be involved.

``The other shuttle missions we watched on TV,'' said Fretter. ``Now, from the interns to the engineers, there is more anxiety that it works fine. But we are ready to do what it takes.''

The mending kit was developed by ATK Thiokol, an aerospace contractor based in Brigham City, Utah. To make sure their tools can withstand heat of re-entry, Ames engineers relied on the Arc Jet machine -- a 15-foot-long box of ``contained lightning'' with enough power to continuously heat 10,000 homes. The powerful machine has been used to test heat shields used on many spacecraft, such as the recently deployed Mars rovers and the old Viking probes that explored Venus. Inside, coils of cooling hoses adjust the temperature, which can heat materials up to 3,000 degrees Fahrenheit -- the temperature shuttles can reach as they re-enter Earth's atmosphere.

Into the giant flamethrower, the engineers dangle two instruments: a 4-inch-long crack repair kit made of reinforced carbon-carbon -- a dense, charcoal-like material resistant to very high temperatures that has been used on tips of ballistic missiles.

The cracked surface can be caulked by astronauts if tiny fissures appear. The other device is a flat, circular patch seven inches in diameter, which astronauts can use to plug a puncture in the spacecraft's nose or wing. Once aloft, Discovery's crew is set to conduct tests inside the cargo bay to see how well they can wield the tools in the vacuum of space.

Frank Hui, one of the Arc Jet aerospace engineers who has been running these experiments -- more than 70 tests in one year -- said his work feels personal to him. He knows Steve Robinson, a crew member on Discovery who used to work at Ames. Also, he was an intern at Ames during the 1986 Challenger disaster when seven astronauts died during a launch failure.

``It was horrendous,'' Hui said last week as he watched the Arc Jet's orange flame blast materials to be used on a future NASA flight to Mars. ``They are our buddies up there. We want to see them home and walking on the ground.''   link


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