Shuttle Fleet Grounded Again

UPDATE: NASA now says "Foam Might Have Struck Discovery."

NASA grounded the space shuttle fleet on Wednesday after determining that a large piece of insulating foam had broken off Discovery's external fuel tank shortly after liftoff Tuesday morning:

"Until we fix this, we're not ready to go fly again," William W. Parsons, the manager of the shuttle program, said at a news briefing at the Johnson Space Center here on Wednesday evening.

According to the New York Times, Discovery's foam incident occurred two minutes after the launch, at a point where the atmosphere is so thin that the piece drifted away. The Columbia accident occurred in part because the foam fell off the tank about 82 seconds after liftoff, when the air was much thicker and slowed the foam so the climbing orbiter struck it with great force:

N. Wayne Hale, the deputy manager of the shuttle program, said that if the Discovery foam had been shed earlier, "we think that it would have been really bad."

How very disappointing and extremely fortunate.

The photos are handheld still images taken by Discovery's crew of the external fuel tank as it was jettisoned after launch on July 26. Initial analysis of the imagery shows a large piece of foam that separated from the tank during the Shuttle's ascent to orbit. The foam detached from an area of the tank called the Protuberance Air Load (PAL) Ramp. This debris also was identified during ascent from a live video camera mounted on the external tank. The television view indicated the debris did not impact Discovery. In this still image, the area of missing foam on the tank is indicated by a light spot near the upper edge of the tank just below the liquid oxygen feedline. (Image Credit: NASA)

California Yankee's previous post on this debris problem are available here and here.

Comments

[mark]

I guess the word I was looking earlier for was 'cohesion'(in regards to the tiles to the ship). Looks like it may actually be the 'caulk'.

[thomas riccardo]

As far as India or China becoming the next Space Superpower Is stretching reality somewhat even though both countries are advancing.
Russia and Europe are the true competitors to the U.S. and have caught up to us and perhaps are passing us up with all the mismanagement of our Aerospace Industry from Boeing to Nasa.
The Europeans are building thier own space shuttle and other space projects are in the works.
Maybe If our press would cover what happens in the world more truthfully we would know these facts.
Instead of bashing France maybe tell the truth and let the public know that they are one of the top 3 aerospace countries of the world or the Russian Space agency who's program is again in Highgear.
Just like all the other industries that we have lost our lead in I guess It is just the same old pattern of lies while the rich take their money out of the country to other parts of the world and slowly (maybe quickly?!) destroy the country.

[mark]

I would expect them to replace the tiles and inspect them.

Still, unless all tiles are replaced and the layer between the tiles and the hull is done over each time, it seems impractical.

Spot replacement would mean that while some tiles are new, some are older.

Any debris that might accumulate between the tiles and the hull is a potential disaster. Extremely high temps will do some crazy things to matter. Dust, air, polymers, causing micro expansions/explosions is possible, or more simply poor bonding.

Heat of reentry likely exceeds the temps at which the welding(if they are welded on) occurs, and as you have noted, tiles routinely fall off. Why does it happen?

[Mashiki]

Mark, all tiles are checked after the shuttle goes in for maintance. I believe they use a gamma ray machine to check for structual fatigue as well. If you've never seen some of the tiles some are thicker then a can of pop. Bad tiles are removed, cracked tiles are replaced, most of the tiles are good for many many runs however.

Every re-entry tiles are lost as well, it's a given. If however the tiles are lost or damaged on a critcal point, then the orbiter is in real trouble.

Privatizing NASA is a poor idea, just remember all the advancements that have directly come from it that would have taken much longer if this wasn't 'public' doman; rather then private. NASA, DARPA, and other programs exist for a reason. If you haven't figured out why, you are failing to understand how much of a spin-off government sponsored research into semi-private and pubic domain has paid off.

[mark]

When I hear the word 'tiles', I inherently think of bath or shower tiles.

Over time though, that which kept them in place wears out, and they are no longer as strong.

Seems that the whole idea of tiles, implies that the tiles themselves are not part of the ship and subject to removal. I'm sure in their effort to make the shuttle resistant to heat, many layers, of varying substance are involved.

As the chain is only as strong as its weakest link, (and this is the hypothetical,) is it possible that there is a layer, or even a coat of heat resistant paint/'glue', or even solder/welding, that will over time degrade?

IT may not just be an issue of impact blowing the tiles off, but years of use, and weakened attachment to the shuttle, brought about by the intense heat of reentry?

I have an extremely bad feeling about their return, and hope this is the last (and SUCCESSFUL) flight of the shuttle.

[let the warhawks fight the war]

right. Privitize NASA and you'll have more safety problems. We learned our privitization lesson when we deregulated the airlines, didn't we?

The private sector has never shown any interest or inclination to further the American space program. Besides, why bother doing it here in the states when you can just outsource to India or China?

[No Oil For Pacifists]

The time has come to ground the shuttle and privatize NASA.