[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

NASA grounds fleet until foam is fixed



NASA grounds fleet until foam is fixed

Though dinged, Discovery seems in good shape, officials believe

BY JOHN KELLY and
TODD HALVORSON


Foam chunk from external tank. Engineers believe the foam that was shed 
from the shuttle's external tank, above, is believed to be 24 to 33 
inches long, 10 to 14 inches wide, and a few inches thick. NASA


HOUSTON - NASA is grounding the shuttles again after a terrifying close 
call during Discovery's launch Tuesday.

A huge chunk of foam broke from the redesigned external fuel tank and 
narrowly missed the spaceship's right wing as it rocketed into orbit.

The 24- to 33-inch-long piece of foam insulation peeled free from a part 
of the fuel tank that NASA engineers had identified as one of the 
highest-priority modifications needed to prevent a repeat of the debris 
strike that caused the disintegration of shuttle Columbia and the death 
of its crew in 2003. NASA managers, however, decided to put off 
redesigning the suspect site until some time after returning the 
shuttles to flight.

"We were wrong," shuttle program manager Bill Parsons said Wednesday 
night in a blunt admission that NASA has failed to fix the fuel tank 
foam despite spending two-and-a-half years and more than $200 million on 
the problem.

The shuttles will not fly again until the problem is fixed, but Parsons 
said he does not know how long that will take. Any further study or 
modification of the fuel tank almost certainly will prevent the planned 
September launch of the shuttle Atlantis.

For the time being, NASA's legions of engineers and experts are focusing 
their efforts on shepherding Discovery's crew through the remainder of 
its 12-day mission to the International Space Station and bringing them 
safely back to the Earth.

NASA officials stressed that Discovery's astronauts do not appear to be 
in danger based on the early review of video and photographs from 
Tuesday morning's launch. In fact, the crew found no obvious major 
damage in an unprecedented inspection of the heat shield in orbit 
Wednesday. However, deputy shuttle program manager Wayne Hale said it's 
too soon to give Discovery a "clean bill of health."

NASA's top post-Columbia priority was to prevent foam insulation, ice 
and other debris from falling off the shuttle's external fuel tank in 
flight, a problem that dates back to the first shuttle mission in 1981. 
Accident investigators also ordered the space agency to develop ways to 
inspect the heat shield in space and repair any damage if necessary.

Last month, an independent review panel headed by former astronauts Tom 
Stafford and Dick Covey determined NASA had not fully satisfied accident 
investigators' recommendations to prevent debris coming off the tank.

On Wednesday, Parsons expressed disappointment about the large piece of 
foam whizzing past the orbiter's right wing about two minutes after 
liftoff Tuesday. The debris came from the "protuberance airload ramp," a 
thick strip of foam near an electric cable tray and 70-foot pipeline 
running down the side of the tank. The carefully-shaped foam ramp is 
critical to the shuttle's aerodynamics.

The hand-crafted foam is similar in size to the suitcase-sized wedge 
that blasted a six- to 10-inch hole in Columbia's left wing, a breach 
that went undetected during the 16-day mission and ultimately caused the 
ship to be torn apart during atmospheric re-entry on Feb. 1, 2003.

The piece of foam ramp from Discovery's tank also is many times larger 
than the size shuttle engineers deemed big enough to do catastrophic 
damage. A digital camera in the belly of the shuttle snapped 
crystal-clear pictures of the a gaping hole left by missing foam on 
Discovery's tank after it fell away from the orbiter. According to The 
Associated Press, engineers believe the irregularly sized piece of foam 
was 24 to 33 inches long, 10 to 14 inches wide, and between 2 and 8 
inches thick.

"We think that if this had come off earlier, it would have been pretty 
bad," Hale said.

The setback could push the next shuttle flight into 2006, further 
delaying resumption of space station construction. Parsons spoke in 
terms of months rather than weeks when he discussed how long it might 
take to resolve the latest foam debris problem spot.

"Until we're ready, I don't know when that might be," Parsons said. 
"Obviously, we have to go fix this."

Meanwhile, more than 200 engineers will continue studying video, 
photographs and radar data to make certain Discovery's fragile thermal 
protection system will hold up during a fiery atmospheric re-entry on 
Aug. 7.

The review thus far identified several areas of concern, which were 
forwarded to the crew of the International Space Station because they 
will get a chance to take high-resolution digital pictures of the 
orbiter this morning as it approaches the orbiting outpost.

The most notable damage sites were a chipped tile on the nose landing 
gear door and an apparent ding in a tile forward of the area where the 
orbiter's fuselage blends into its wing. The damaged tiles do not appear 
to be more serious than the kinds of flaws that shuttles survived on 
past missions, but NASA is treating every possible flaw with respect.

"The last flight ended in catastrophe, and we lost seven friends of ours 
because of (heat shield) damage," lead flight director Paul Hill said.

Consequently, any potential damage is "going to get our attention, and 
we're going to be concerned about it," he said.

The shuttle astronauts could be asked later this week to do additional 
focused inspections of some specific "areas of concern," NASA said.

Discovery's astronauts also have been trained to carry out small tile 
repair jobs, but it's unlikely they would be called on to do so. 
Techniques developed to date are considered rudimentary and have not yet 
been tested in orbit.

In a worst case, the shuttle astronauts would seek safe haven on the 
space station and Atlantis would be launched on a rescue mission. 
However, shuttle managers acknowledged Wednesday evening they would be 
faced with a tough decision about whether to launch Atlantis, knowing 
there is a major, unfixed debris hazard capable of dealing a 
catastrophic blow to the orbiter. That would put another crew at risk.
----
Via the sarex mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe sarex" to Majordomo@amsat.org



AMSAT Top AMSAT Home