Columbia Tragedy
Columbia Tragedy
(OP)
Does anyone know the current status of the Columbia investigation ? I saw some time ago that they had physically simulated the foam impact and found that it could have penetrated the wing. I recall reading that an engineer had done a study during the flight, using a "spreadsheet", and concluded that the foam impact was negligable. If so where did they go wrong ? Was it because :
a. The mass of the foam was underestimated
b. The impact velocity of the foam was underestimated
c. The strength of the tiles or their attachment quality was overestimated
d. The hardness/strength of the foam was not correctly accounted for
e. The part of the wing that was impacted was not the same as that assumed in the calculation
f. A combination of the above
g. The person who did the calculation was asked to calculate the wrong thing
h. A caveat in the person's answer was ignored
i. None of the above
Of course, I doubt if anyone reading this who really knows the answer, even if they exist, would be allowed to comment. But it seems to me that the Challenger investigation was a little more open than this one. Is this my imagination, or was it perhaps due to the presence on the committee of Richard Feynman the first time around ? I know one thing - I would not have wanted to be placed in the position of doing that quick spreadsheet calculation for management during the flight.
a. The mass of the foam was underestimated
b. The impact velocity of the foam was underestimated
c. The strength of the tiles or their attachment quality was overestimated
d. The hardness/strength of the foam was not correctly accounted for
e. The part of the wing that was impacted was not the same as that assumed in the calculation
f. A combination of the above
g. The person who did the calculation was asked to calculate the wrong thing
h. A caveat in the person's answer was ignored
i. None of the above
Of course, I doubt if anyone reading this who really knows the answer, even if they exist, would be allowed to comment. But it seems to me that the Challenger investigation was a little more open than this one. Is this my imagination, or was it perhaps due to the presence on the committee of Richard Feynman the first time around ? I know one thing - I would not have wanted to be placed in the position of doing that quick spreadsheet calculation for management during the flight.





RE: Columbia Tragedy
Rod
RE: Columbia Tragedy
RE: Columbia Tragedy
RE: Columbia Tragedy
TTFN
RE: Columbia Tragedy
http://www.aviationnow.com/avnow/spSec/sts107.jsp
That will link you to the index of their stories on the subject, but note that the list stops at May 12. I've seen stories published since then, but they don't seem to be in the index.
The ultimate conclusion, for lack of any contrary evidence, seems to be that the insulation impact is the major cause, though the board resisted (they claim) jumping to that conclusion all along. Many of the board's recommendations revolve around closer monitoring of the launch phase (to identify damage) and inspections on the ground (of course).
I would add that I saw a photo taken by Ilan Ramon that shows a big dent in the wing, which doesn't seem to have been given the amount of "coverage" that I expected. When I saw the picture, it looked like the smoking gun to me, but I haven't heard about it since.
STF
RE: Columbia Tragedy
http://www.nasa.gov/columbia/foia/index.html
http://spaceflight.nasa.gov/shuttle/investigation/
RE: Columbia Tragedy
Have not yet heard of a final report.
While Raytheon may have built the O-ring that failed in Challenger, it was the "do it at whatever cost" mindset at NASA in those days that enabled the failure.
RE: Columbia Tragedy
RE: Columbia Tragedy
http://spaceflight.nasa.gov/shuttle/investigation/, it appears that the investigators are now convinced that something like 1.67lbs of debris hit the wing at 775 ft/sec or thereabouts. Now that's a hell of an impact! They also are now saying (not surprisingly) that this probably caused "catastrophic damage", based on testing. But I distinctly recall the guy who was in charge of the program (who has since "resigned" - can't recall his name), saying within the first few days after the accident that the impact could not possibly have caused any significant damage. So somewhere between then and now, they have completely reversed themselves. I'm not saying that I or anyone else could have done any better, but I'm still fascinated to know where the error was made in the original "back of the envelope" calculation, details of which appear conspicously absent in all the above references . Whether such a calculation could have saved the crew members, even if carried out correctly and acted upon, will probably never be known of course.
RE: Columbia Tragedy
The guy you recall is Ron Dittemore - more info here:
http://spaceflight.nasa.gov/spacenews/releases/2003/H03-149.html
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Columbia Tragedy
RE: Columbia Tragedy
RE: Columbia Tragedy
RE: Columbia Tragedy
As the foam peels off the rocket it is travelling at rocket speed, ie at zero speed relative to the shuttle. At that altitude/speed how quickly would it accelerate up to the relative speed they used in the test? Does that add up?
Cheers
Greg Locock
RE: Columbia Tragedy
RE: Columbia Tragedy
My apologies if I didn't read thoroughly enough to catch this.
RE: Columbia Tragedy
RE: Columbia Tragedy
It also looks like shuttle manager Linda Ham is getting hung out to dry (among others) for not pursuing the possibility of imaging the damage:
"Linda Ham said it was no longer being pursued since even if we saw something we couldn't do anything about it".
It is sad to see how things have changed since the glory days of the Apollo 13 rescue.
RE: Columbia Tragedy
So what ?
SOFI Foam - often described as the consistancy of Shaving foam -- always breaks up into a fine mist when hit with a 1500 mph wind.
The Cameras showed this.
The Commission ignored that several percent of the Upper wing surface blew away long before any significant heating (and I mean even just 6 degrees -- the thermostats read in 6 degree steps).
Effect before Cause.
And ignored that a stress sensor went wild first, and temperature increases only occur to its left until AFTER the stress changes sign to a peak 4 times the magnitude, or that the temperature rises 4 times as fast to the right, a QUANTITATIVE agreement that Stress CAUSES the problem.
They ignored that all wires die from Top down (except the ones that drop in temperature to a cryo-death: the 7 rearmost. These die in order from the rearmost, forward --obviously a LH2 fuel leak from the fuel cells (in fact the Astronauts regained control 30 seconds after a third of 1 wing broke off and stabilized the satelite connection with 2 sensors in the Left wing still reporting good data -- then 2 seconds later EVERY electrical system blew at once).
They ignore the elevon actuator hole (so similar to Challenger's Right wing pre-breakup burnthrough).
Or to the melting of all wires in the back of STS-90, notable for sharing Wind Shears with the 2 Disasters -- which photos have proven are actually gouts of flame out of the O-ring joints (at least for Challenger (see Spaceflight May 1988: made the Cover in England but BANNED in the U.S.), but Ali AbuTaha's calculations imply locales just above the Struts are metal-fatigued at Launch thus the flames hitting the same target (control surfaces of the wing), roughly
-- and every time "they" cancel NASA's internal Accident teams and convene "unbiased" (read: ignorant, politically correct) Panels with Zero Rocket Scientists to claim (with No evidence) that they are reentry events).
-- and why do we only lose Shuttles just after a Government agency with a grudge against NASA, is allowed to "take over" NASA, gutting the budget, firing so many Scientists they have to farm out every question to companies (eg the contract to Boeing to look at the foam, or, Thiokol's to have their people "put on another hat" in order to get a second opinion (although there NASA had no SRB experts -- Mulloy was a liquid man serving under protest because all Solid Rocket Experts in the World boycotted NASA as long as the Budget people insisted Solids were "safe" when they never figured out WHY the 260 inch failed.
And of course, all 3 Shuttle hardware losses - on STS-4 both Solids sank - were drought Missions.
The 110 non-drought had a perfect record.
And the normally 1% explosion //2% overall loss rate Delta lost 2 to explosions & ran 1 into a Low orbit (of 3 just prior to Columbia's launch) due to low SRB performance from the fuel being spat out in chunks (guess which Shuttle missions had that? STS-4, Challenger Loss (not a low orbit but lots of impact damage showing chunks of fuel, though the Panel voted a violation of Conservation of energy explanation that Ice falls might break a wrist-thick steel bar & throw it several times the Fall distance, out of the search area), and the Columbia Loss.
Coincidence?
Hardly.