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NASA Test Shows Foam Could Be Culprit
Ben Hutchings writes "The BBC has a report on an impact simulation that aimed to recreate the impact of insulating foam on Columbia's wing. The result was a large hole that probably could not be repaired in orbit even if it was known about."
It'll be interesting to see what the reaction to this failure will be.
Challenger didn't really rock the way we did Shuttle missions because the problems that led to its explosion were not core to how the Shuttles are built -- someone / some process screwed up and there was a relatively reliable way to make sure it wouldn't happen again.
Columbia, on the other hand, was destroyed because the design of the Shuttle is so fragile that once you develop an external problem, you're dead -- since they're using tiles that are individualized, there are no spares they could carry that would help them fix this sort of problem.
Hopefully, this will be a step in the right direction -- either a radical redesign of the Shuttle, or its abandonment in favor of a more robust solution.
The impact was so violent that it popped a lens off one of the cameras recording the experiment and prompted gasps from about 100-strong astonished crowd.
When I hear of "entertaining" demonstrations to prove a point, I'm reminded of magicians before an audience and furrow my brow.
Is the real "secret" here a less visually spectacular flaw, not in a bodypart but in the design process and it's assumptions?
"It's not your information. It's information about you" - John Ford, Vice President, Equifax
It's amazing to think that prior shuttle launches have had foam break off and strike the wing without this happening (according to Discovery Channel). Makes me wonder what was different, perhaps just the size of the foam chunk. It's good to know they finally tested it out to measure the impact. Tragic that people died first. Here's a link to another article on VOANews.com
Does this also account for the the angle at which the foam in the wing? They don't mention it so I thought it was a question worth asking.
My understanding was that the foam glanced off the wing at high speeds and wasn't simply "shot" into it from a right angle. I may be completely wrong (and would love to be corrected) on my misunderstanding.
This obviously wasn't the same kind of foam we use to sleep on when we go camping.
in this case, where heatup during reentry would be a huge problem with a damaged wing, I was wondering if they could bring the shuttle in at a very oblique trajectory consisting of many orbits of slightly-decreasing radii to aerobrake it orders-of-magnitude more gradually than they currently do now.
make world, not war
Can the impact speed be really that fast? Before the piece of foam fell away from the shuttle, it was moving at the same speed. To impact at 850 km (530 miles) hour, the piece of foam would have to slow down 850 km/h during the short distance between falling off and hitting the wing... during 2 seconds or so. Are the numbers really feasible?
The ISS was out - it was on a different orbit and the Shuttle didn't have enough fuel to make the transition.
On the other hand, I have also wondered why the hell they couldn't send up an empty shuttle and bring everyone back on it. Moreover, once the Columbia had been emptied, they could have tried to bring it back with out bleeding off speed using S turns. The Columbia broke apart as it was slaloming and had just loaded up the damaged wing. Had they known the wing was busted, they may have been able to slide slip the whole way in and kept the damaged wing trailing on the backside the whole way down.
All those ideas go out the door when the shuttle manager said "Even had we known, there was nothing we could have done." For that sentiment alone, he deserved to go - it was a far cry from Gene Kranz'es "failure is not an option" attitude when Apollo 13 blew an oxygen tank.
Columbia was in the wrong sort of orbit to be able to rendevous with the ISS, nor was it capable of generating enough delta-v to enter a rendevous orbit.
This is one of the reasons the board recommended that all future shuttle flights (apart from the already scheduled Hubble Servicing Mission), fly to the ISS, or in Orbits that are capable of rendevousing with the ISS.
I read the news story...including the part where they said, "we could do this again, and get a different result".
So, first, how about doing this at *least* three times?
THEN, take the average, and put the damn thing in front of a horizontally-mounted rocket engine, to simulate actual re-entry, and see if it happens...or if, as has happened in the past, the shockwave keeps the heat from penetrating.
Gee, if that happened, then they'd have to go back to looking for another cause...like (google for it) the diehard's analysis that it was stress corrosion cracking in the hydraulic lines that control the elevons. Loosing control of them would rip the wing *right* off.
But then, stress corrosion cracking shold have been caught...*if* they hadn't cut safety inspectors by 75%, and if the managers, in their own meetings, cared more for safety than for "being a team player, and meeting the schedule".
NASA's management strucure needs flattening, anyway - there's maybe 1 chief for 2 indians. Is that sane, to y'all?
mark
Because prior to this accident, the concensus opinion at NASA was that the foamed insulation was low-mass and crumbled easily enough that it didn't pose a threat to the vehicle. In fact, the mixture of foam being used had been in place for five years. In STS-87, the first time it was applied to Orbiter Columbia, foam debris caused 308 hits on the orbiter, some resulting in deep gashes. After changes in the method of application, the foam was rendered more secure, but chunks continued to break off in future flights.
Still, none of those flights exhibited the kind of damage that would lead to the Columbia tragedy until now. It seems perfectly obvious to "monday-morning quarterbacks" that the foam was a problem, but five years of experience suggested otherwise.
back in 1993, british amateur inventor maurice ward created a plastic he called "starlite", which would withstand temperatures of up to 2700 celsius (that of a nuclear explosion). does anybody know what temperatures are reached during reentry, or for that matter, what happened to ward & starlite? i tried googling but didn't find anything interesting.
ed
Let's see, prior to STS-86 and while CFC-11 was still used as propellant, sprayed-foam insulation loss was minimal, sporadic, and concentrated around a few problem areas and was characterized by small debris. After that, the loss became common, resulting in significant damage to STS-87 and other flights and was characterized by much bigger chunks shedding off random areas of the external tank.
So, yes, it most certainly is the new formula that caused the problems.