One of my fave punk 7"ers...
Posted on 08/13/2004 3:36:38 PM PDT by ZGuy
The foam that struck the space shuttle Columbia soon after liftoff -- resulting in the deaths of seven astronauts -- was defective, the result of applying insulation to the shuttle's external fuel tank, NASA said on Friday.
The official investigation into the accident, conducted by the Columbia Accident Investigation Board, left the matter open, since none of the foam or the fuel tank could be recovered for study.
A suitcase-sized chunk of foam from an area of the tank known as the left bipod, one of three areas where struts secure the orbiter to the fuel tank during liftoff, broke off 61 seconds into the flight on Jan. 16 of last year. It gouged a large hole in Columbia's left wing.
The damage went undetected during the shuttle's 16-day mission, but caused the nation's oldest spacecraft to break apart under the stress of re-entering the Earth's atmosphere on Feb. 1, killing the astronauts.
"We now believe, with the testing that we've done, that defects certainly played a major part in the loss. We are convinced of that," said Neil Otte, chief engineer for the external tanks project. He spoke at the Michoud Assembly Facility in New Orleans, where the half-million pieces of every shuttle fuel tank come together.
The fault apparently was not with the chemical makeup of the foam, which insulates the tanks and prevents ice from forming on the outside when 500,000 gallons of supercold liquid hydrogen and liquid oxygen are pumped aboard hours before liftoff.
Instead, Otte said NASA concluded after extensive testing that the process of applying some sections of foam by hand with spray guns was at fault.
Gaps, or voids, were often left, and tests done since the Columbia accident have shown liquid hydrogen could seep into those voids. After launch, the gas inside the voids starts to heat up and expand, causing large pieces of insulation to pop off.
NASA said this happens on about 60 percent of its shuttle launches.
For the bipod foam, the entire ramp was apparently torn away. It weighed only 1.67 pounds (0.75 kg), but at the speed involved, it hit the orbiter with enough force to shatter the reinforced carbon-carbon panels of the wing's leading edge.
NASA has made extensive changes in the foam-application process, but still has tests and perhaps more procedural changes before the tanks can be certified for flight.
"It was not the fault of the guys on the floor; they were just doing the process we gave them," Otte said. "I agree with the (accident investigation board) that we did not have a real understanding of the process. Our process for putting foam on was giving us a product different than what we certified."
Recertification is now the biggest obstacle for the tank program. New standards require that no foam pieces heavier than about half an ounce can come off the tank during the first 135 seconds of flight. That is much smaller than the divots that have routinely popped off.
NASA also hopes to recertify the 11 fuel tanks that were ready for flight prior to Columbia once modifications are made. Each tank represents about a $40 million investment.
On one of the threads here on FR concerning the "foam", IIRC , there were some Freepers who stated that the reason the "foam" composite was changed on the tanks, was due to the complaints from the "Save-The-(fill in your favorite sea creature here)."
They complained that after the tanks completed their tasks, and fell back into the ocean to be retrieved later, the "creatures of the sea", who mistook it for a food scorce, were dying because of it's "toxic" properties.
So NASA tried to come up with a substitute, and what they are using now was the substitute.
IIRC,( and if any Freepers can check this to see if I got it wrong),the tank that was used on the ill-fated was the FIRST application of the material. THAT tank was to be used on a previous shuttle flight, but that flight was canceled, the tank was "unused", so it was "returned to inventory."
The tank(the one with the FIRST attempt at applying the "new" insulation,) was brought out of "storage" because the other tanks were already with other shuttles getting prepared for future launches, so it was put into use on the mission that ended in such tragedy.
It's not like I have ever been wrong about something before,(at least according to my wife,)but IMHO, what I posted here was (seared....seared I tell you) close to what I remember freepers explaining about the "foam".
So, then, like, what are they gonna do? Wrap the environmentally-friendly foam with environmentally-friendly chicken wire to hold it all in place?
Just build the "space elevator" and be done with it. I know, we don't have the nanotube technology yet. Oh well.
Some of FR knew. The NASA-bots were quite aggressive and profane in defending NASA's denial.
They're going out of their way to try and say it's not the fault of the extreme left envirocommies. Ridiculous.
Ping!
I'm not sure how true this is. Apparently, the conpound was changed from the original formula to satisfy environmental whining. Foam shearing off has been an issue ever since.
There are more problems with that than just the material science. The top of the structure will oscillate and there is also the huge electric potential this would generate. We ran some back of the envelope numbers and hit some snags right off the top.
IMHO, the real problem was the banning of the solvents formerly used to prep the area for bonding and replacing them with the "environmentally-friendly" ones.
This was discussed heavily on bones' thread, which I can't seem to locate at the moment. Also, bones has been banned.
If the space elevator cable breaks below the midpoint, would the resulting falling cable debris be as catastrophic as some have described?
True.
Okay. We should start with a small pilot project. Maybe a couple bridges--to Cuba, across the Formosa Strait, across the Bering Strait, across the Strait of Gibralter-- would iron out some of the kinks.
thanks for the ping, Thud.
Ping Kevin
we discussed this problem years ago, and I personally posted several pictures of possible patches which may have detached.
I am very glad they are finally getting around to solving the problem, after only 20+ years.
It sure does. Thanks for the ping.
I see the folks over on the "Observation" thread have seen it also.
..w/o doubt.."lets' soar w/ the eagles and not slide w/ the slugs"..onward and upward. :/
...Hmm, Hadn't heard that before. Make sense though...Burt Rutan's effort have typically been efficient (weight/strength/$$$$) use of technology @ hand.
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