NASA grounds shuttle fleet

Launch debris forces halt

Discovery's flight goes on

July 28, 2005|By John Johnson Jr. | John Johnson Jr.,LOS ANGELES TIMES

HOUSTON - NASA put future space shuttle flights on indefinite hold yesterday after agency managers acknowledged that a piece of insulating foam nearly as large as the piece that doomed Columbia in 2003 fell off Discovery's external fuel tank during launch.

The announcement of what NASA called a "debris event" threw the shuttle program into disarray a day after tens of thousands, including first lady Laura Bush, cheered Discovery and its seven-member crew as they began a mission to the International Space Station.

NASA managers said that there was no evidence the shuttle orbiter was hit or damaged by the foam. But the loss of a bit of foam after two years of study and $1.4 billion in upgrades to the shuttle was a blow both unexpected and disappointing.

"We have to take a step back," said Bill Parsons, shuttle program manager. "Until we're ready, we won't go fly again."

The next planned launch was that of Atlantis, as early as September.

NASA managers said, however, that Atlantis could be used as an emergency rescue ship to retrieve the astronaut crew from the space station if Discovery did suffer serious damage. They called any quick launch of Atlantis unlikely.

During Tuesday's launch, NASA cameras and radar found that a 1 1/2 -inch section of heat-resistant tile sheared off from the nose landing-gear door. NASA managers said yesterday that they did not think the incident was a problem but they were still studying what happened.

NASA officials did not address the question of whether they would have the crew repair any damage found in space. The crew plans to use a spacewalk to test several repair techniques for the heat-resistant tiles as well as the reinforced carbon panels covering the leading edges of the wings and the nose cone. But several crew members have said that they would be reluctant to trust their lives to untested technologies.

The only other escape route would be a Soviet Soyuz vehicle, but it can't carry a full crew. And food on the space station would last only about 40 days. But NASA officials said it was far too early to speculate about damage to the orbiter.

"The good news is, the orbiter appears to be in good shape," said N. Wayne Hale Jr., the shuttle's deputy program manager. Yet Parsons could not say positively that the foam did not hit the orbiter.

Hale pointed to video images that appear to show it drifting away from the orbiter, not toward it, as the boosters separated from the shuttle about two minutes after launch.

NASA engineers are continuing to download photographic and film images of the launch and expected that by today they would be able to say more definitively whether the piece of foam hit the orbiter, and where.

The piece of foam that came off was on the Protuberance Air Load Ramp, or so-called PAL ramp, just above the liquid oxygen feed line on the external fuel tank. The ramp provides protection against the supersonic forces the shuttle is subjected to as it drives against gravity from zero to 17,500 miles an hour in the 8.5 minutes after launch.

"We cannot fly with PAL ramps coming off. We have to go fix this," said Parsons.

The foam was estimated to be up to 33 inches long and 8 inches wide. That was about the size of the foam piece that hit the leading edge of the left wing on Columbia as it lifted off in January 2003. At that time, most NASA officials believed foam, which is applied to the super-cooled external tank to keep iced from forming on the outside, could not harm the orbiter. In fact, the foam tore a hole in the wing. When Columbia attempted to land Feb. 1, 2003, air heated to 5,000 degrees Fahrenheit rushed into the cavity and tore the orbiter apart, killing all seven astronauts.

"We're treating it very seriously," Hale said of the new finding. "Are we losing sleep over it? Not yet."

Meanwhile, the Discovery crew completed their second day in space, using remote equipment to scan the hull for damage and preparing for today's scheduled docking at the space station. One purpose of the trip is to take supplies to the station and to replace a failed gyroscope.

Managers also said the crew would perform a special scanning maneuver tomorrow of the underside of the orbiter, using a boom with a camera and laser equipment installed just for that purpose. They will be looking at several places where bits of tile broke off during launch. Although a deep enough gouge could be hazardous to the orbiter, officials said they don't believe the thermal protection system has been compromised.

Still, engineers are building a mockup of the nose gear area and will test it in the heat of an arc jet before deciding whether the dings need repairing.

The crew had been informed of the problems, NASA said.

The Los Angeles Times is a Tribune Publishing newspaper.

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