Images of Endeavour's Damaged Tiles

Roland Piquepaille writes "Neptec Design Group, a Canadian company and a NASA prime contractor for 25 space missions, was kind enough to send me exclusive images of Endeavour's damaged tiles during its last take-off. So here are some of these pictures" The pictures are pretty amazing and make the urgency of this whole thing much more amazing.

Comments

Re:Err on the side of caution...don't you think?

[grommit]

You do realize that the Shuttle has landed many times before the Columbia disaster with whole tiles missing. This most likely is a non-issue although I'm glad NASA is treating it seriously. Besides, these tiles are on the belly of the orbiter. The damaged RCC panels on Columbia were on the leading edge of a wing where there are greater temperatures on reentry.

I don't think you realize the inherent danger in attempting to fix these either.

Re:How long has this been happening?

[SomeGuyTyping]

from Wikipedia (http://en.wikipedia.org/wiki/Space_Shuttle_extern al_tank):

Development of the ETs thermal protection system has been problematic, and has proven a fatal weakness to shuttle mission safety. NASA has had difficulty preventing fragments of foam from detaching during flight, ever since a 1995 decision to remove chlorofluorocarbon-11 (CFC-14) from the composition of the foam in compliance with an Environmental Protection Agency ban on CFCs under section 610 of the Clean Air Act. In its place, a hydrochlorofluorocarbon known as HCFC 141b was certified for use and phased into the shuttle program. The "new" foam containing HCFC 141b was first used on the aft dome portion of ET-82 during the flight of STS-79 in 1996. Use of HCFC 141b was expanded to the ETs acreage, or larger portions of the tank, starting with ET-88, which flew on STS-86 in 1997.

wrong

[everphilski]

Oh, and for another tidbit. Ice, since its denser, and heavier than the insulating foam, is a bigger problem than the foam is when it breaks off. It takes a smaller chunk of ice to break off and smack the orbiter to cause an equivalent amount of damager to a larger chunk of foam.

Foam does more damage than ice. Ice is dense and keeps its velocity high, which translates to a low velocity relative to the shuttle. Foam on the other hand is much less dense and slows down very quickly, translating to high velocities relative to the shuttle.

Remember, kinetic energy = 0.5 * mass * V^2. Velocity is what kills, not mass.

Re:How long has this been happening?

[Mr. Slippery]

environmentalist groups got their way and now we have a riskier space program.

This point about how the foam insulation process was changed has come up many times in discussions about the damage to Endeavor. And it's wrong.

It has its origin in one of Rush Limbaugh's lies. As it turns out, the foam that dealt Columbia the death blow was the old-style CFC foam. The problem was in the hand-spraying application method used on that area, which left gaps and voids in the foam.

Yes, when they first started using the CFC-free foam in 1997 there were some problems seen. Changes were quickly made to improve the adhesion.

There were also plenty of problems with the CFC foam - "popcorning" from trapped air bubbled was noted in 1995, while in 1992 Columbia was struck by a large piece of foam, ripping a 12cm gouge in the tiles. Both of these were before the switch to CFC-free foam.