NASA Finds 4-5" Crack in Shuttle Insulation

PresidentKang writes "Spaceflight Now is reporting that a large crack has been found in an external tank foam of Space Shuttle Discovery on the launch pad. According to the article: "Engineers inspecting the shuttle Discovery's external tank following Sunday's launch scrub found a crack in the tank's foam insulation near a bracket holding a 17-inch oxygen feed line in place. Some engineers believe the crack must be repaired but senior managers say a variety of options are on the table, from fly as is to making repairs.""

Comments

And what about the pilots?

[DHalcyon]

"...but senior managers say a variety of options are on the table, from fly as is to making repairs."

I wonder what those managers would say if they had to fly the shuttle.

Re:And what about the pilots?

[jonnythan]

From what I hear, the actual astronauts are much, much more accepting of risk than the engineers or management.

So, I don't think you'd hear the astronauts being the most conservative on this decision just because they're in the ship.

Re:And what about the pilots?

[Anonymous Coward]

IMO, that willingness to take such risks should be rewarded with never having to do so unless absolutely necessary. Whether or not the astronauts themselves are concerned with the crack in the foam, management should be lighting fires under people to make sure they have done everything on the ground possible to ensure a safe launch.

Re:And what about the pilots?

[Anonymous Coward]

They're very well informed about the exact level of risk they're taking. Actually, I think I do remember something about the astronauts being able to stop the launch on their own say-so at any time

Yes, but who keeps them informed?

For example, for the Challenger's last liftoff, there was a "discrepancy between management claiming a 1 in 100,000 chance of serious failure and the engineers claiming 1 in only 100" [ref]. Which one did the astronauts hear? Did they know about the trouble with the O-rings, and the solid rocket booster assembly, and so forth?

I'm a software developer, and I'm pretty well-informed about how my computer works, but I'm not an expert at everything -- nobody is, or could be. And I've fixed my car before, and I'm pretty well-informed about how it works. But I can't say with any certainty the odds of my computer or my car barfing today. Is spacecraft construction so simple that astronauts can be experts at everything?

Shuttle is a political project

[Crashmarik]

Not an engineering project or a business enterprise.
This type of thing is to be expected in political endeavors. Their purpose is never to satisfy the stated goals but to advance constituencies political agendas. For a political project failure is not only an option but often the most desirable one.

Does anybody at NASA have a MEMORY?

[wowbagger]

Does anybody at NASA have a working memory? Don't they remember the results of the Challenger inquest, wherein plenty of evidence of engineers saying "DON'T LAUNCH! BAAAAD!" was ignored?

I fear we may very well get a "fourth to remember", and NOT in a good way! It is all very well for a bottlerocket to explode in flight, NOT A MANNED SHIP!

I fear that NASA is going to launch, come hell or high water, and damned be the consequences.

Re:Does anybody at NASA have a MEMORY?

[Beryllium Sphere(tm)]

>they could not offer a coherent case for changing their stance.

Didn't Boisjoly say that the seals weren't qualified for the temperature on launch day?

"Qualified" is a specialized term related to the adage "Test what you fly, fly what you test". It means that a part has proven itself for a particular use and environment. It's kind of like "rated", but with radically more testing and traceability.

By aerospace standards, as soon as the seals were outside the conditions for which they were tested, they should have been considered untested and barred from flight.

>their decision did not occur in a vacuum.

Thanks for the chuckle!

Re:Does anybody at NASA have a MEMORY?

[EvanED]

There was a small number of engineers who tried to say "Don't launch" at the eleventh hour

You mean the standardly organized preflight meeting?

this represented a near complete reversal of their previous stance

The one formed before the shuttle had been cold soaking in 28 degree weather?

they could not offer a coherent case for changing their stance

Besides the clear evidence that blow-by increased at lower temperatures within the range that they were familiar, that there was one shuttle flight already that had come dangerously close to having the ring burned entirely away, and the 28 degree point being well outside the area they knew about?

Re:Does anybody at NASA have a MEMORY?

[TubeSteak]

That might not be such a good idea.

Other than their lack of specific technical knowledge, the astronauts are also somewhat biased. They live to go into space. They have to be hypercompetitive to get where they are.

It's like asking an injured athlete if he wants to play. The answer is going to be something like "Yes, but the doctor won't let me."

Take out the doctor (engineers) and what are you left with?
"Yes"

Re:How can they fix this

[Nimey]

But if NASA does the sensible thing and mounts the Shuttle's replacement on top of the stack like they did for Apollo, you don't have to worry about ice falling and hitting heat-resistant tiles, because all that's mounted above the fuel tank.

I wouldn't be suprised if the external tank is insulated just because of how the shuttle is mounted on the assembly.

Cold? Maybe. Still needs to be said.

[voice_of_all_reason]

If you can't take a little bloody nose, maybe its time to go home and crawl back under your bed. It's not safe out here. The galaxy is wonderous -- with treasures to satiate desires both subtle and gross -- but it's not for the timid..."

-Q, "Q Who?"

Re:How can they fix this

[jwagner95]

I don't think that's the point, but you still have to take it part of the way.

By keeping the tank's metal stronger you don't need as much metal. The metal's density is much greater than that of the ice. Like the previous poster stated a pound saved on the tank almost directly relates to an extra pound of payload or less fuel required for said pool. That's part of the reason only the first shuttle's ET (external tank) was painted white. I don't remember the exact weight but they were using Titanium based paint that weighed into the thousands of pounds for something like eight coats.

Not surprising

[ClosedSource]

NASA commited itself to solving the foam problem but when it turned out to be difficult they decided they didn't have to solve it. So they found evidence that the problem wasn't solved. How could this be in any way surprising?

Re:Why is changing one's mind automatically bad?

[DerekLyons]

So, well, I won't argue a your point B for lack of enough data, but point A leaves me scratching my head in disbelief. So someone decided that those engineers aren't trustworthy... because they changed their mind? Seems like a pretty weird attitude. I definitely expected that at NASA even management would be a bit more open-minded than that. They're pretty much one continuous experiment and using experimental equipment, so it's exactly the kind of thing that should be _expected_.

The issue is more complex than simply "changing their mind".
 
If they had new data - you'd be correct, the managers would have been insane to have launched Challenger. But they *didn't* have new data - they had a new interpretation, which is what makes point B crucial to understanding the whole issue. They were taking the same data that lead to conclusion 'black' and now claiming it supported conclusion 'white' - but were unable to articulate and justify their change in stance.

Moot point

[StarKruzr]

Either way, the STS needs to go. It's 30-year-old technology, is not truly reusable, and can't do anything at all out of LEO.

We can do far, far better. End the Shuttle program, put the orbiters into museums, and put its operating budget into R&D for a new spacecraft.