NASA Looks at Variables on Fuel Tank - New foam formula used for Discovery

Discovery's external fuel tank was the first to fly with a new insulating foam custom-made to satisfy environmental bans on chemicals suspected of depleting the Earth's ozone layer.

NASA is investigating why a 1-pound chunk of the foam peeled off Discovery's tank two minutes after launch July 26, missing the shuttle's right wing as it climbed toward orbit.

The incident prompted NASA to ground the shuttle fleet even as Discovery was on its way to the International Space Station.

"We are treating this very seriously. We are going to fix this before we go fly," said John Shannon, a senior shuttle manager at Johnson Space Center.

Indeed, Discovery's tank shed four pieces of foam large enough to cripple the shuttle if the pieces had hit it, and NASA records show at least two of those pieces were applied manually using the new formula of foam.

NASA officials will not discuss any emerging theories about why the foam continues to come off the tank. A team of experts from NASA and tank-builder Lockheed Martin are studying possible reasons.

The main focus is on a pillow-sized piece of foam that broke free from a ramp that runs next to fuel pipes and cables, protecting them from turbulent airflow on the violent ride to space. Alterations or repairs made to that ramp are being looked at as a possible contributor to the foam loss, as is is every other change made to the tank.

The change in the chemical make-up of the foam is unrelated to the redesign ordered by the Accident Investigation Board in the wake of the fatal 2003 Columbia accident. Instead, NASA made the change as part of an ongoing bid to meet U.S. and international environmental bans dating to the 1990s.

That's when the federal government started trying to ban ozone- depleting types of freon present in the chemicals used to spray and mold plastic foam for everything from refrigerators to furniture to rockets.

Most of the inch-thick orange foam that covers the tank is sprayed on by robots at a sprawling factory east of New Orleans.

A freon-based chemical is used in that process. For robot-sprayed portions of the tank, NASA's contractor originally used a formula called CFC-11, long since banned. By 1996, NASA had switched to a more acceptable chemical, HCFC-141b, for all but one of the four kinds of foam it was using on the tank at the time.

Then, on three flights in the late 1990s, popcorn-sized bits of the new, environmentally safe foam flaked off in record amounts. A frightening number of dings and gouges on the orbiters' heat shields got NASA's attention.

The freon-free foam was blamed. NASA found a quick fix, changing the way the new foam was applied to the tank to reduce -- but not eliminate -- the popcorning. It's unclear whether the environmentally friendly foam remained a factor in the continuing loss of small fragments of foam on subsequent missions, but NASA records show the agency knew it did not stick to the tank as well as the original foam.

When Columbia disintegrated over Texas in 2003, some blamed the environmental change. That wasn't the case. The big piece of foam that smashed the hole in Columbia's wing was made from the old foam containing the long-banned freon blowing agent. The old substance was called BX-250.

NASA and its contractors were trying to develop a freon-free version of that foam, which workers used to manually craft the aerodynamic ramps and hand-made patches of foam applied once the robots are done spraying that initial layer.

The space agency was still flying the old foam because it had won exemptions to the EPA rules and was making only progressive steps in changing the foam.

In records obtained by FLORIDA TODAY under the Freedom of Information Act, NASA told the EPA that it could not switch the foam formula faster "without jeopardizing the safety of NASA's human spaceflight program." Years of tests were needed on promising new formulas because "qualification testing must be performed to ensure that the material meets all of the requirements for mission success and human flight safety." The records note the agency's struggle with the initial change, and the resulting damage, as evidence it needed more time.

In 2003, as investigators were reviewing the Columbia accident, NASA did certify a replacement for the BX-250 foam that did not include the freon-based agent. The new foam, called BX-265, was ready for the fuel tanks for NASA's first two post-Columbia shuttle missions and is the foam under investigation.

Engineers ultimately might find that the change was inconsequential. Foam loss is not a new problem. Foam hit orbiters on at least 75 of the flights to date. Overall, Discovery appears to have come through its test flight relatively unscathed, indicating NASA's redesign reduced the foam shedding. The heat-shield tiles have taken a record-low number of hits, according to extensive inspections on orbit.

from the Jerry Pournelle web page: http://www.jerrypournelle.com/view/view372.html

What ought to have been done with NASA's billion and a half was: (1) Hire a dozen smart people to design a condom for the Shuttle Tank. Peter Glaskowsky and I discussed this last night: surely the right material for the condom would be America's Cup sailcloth which isn't a cloth but a reinforced carbon fiber film, as light as anything made for its strength. Make a condom of that, encase the tank in epoxy and that condom, and foam chunks won't fall off. It might weigh a few hundred pounds, and so what? (2) use the remaining funds -- a billion at least -- to pay a bunch of small companies out there to work on SSTO, recoverable first stage rocket boosters, and air drop. Get each to build the best X project flying hardware they can build incorporating their approach for the $333 million each will get. Fly those ships. Observe the results and decide which concepts to encourage.

Now none of this is going to happen. NASA has no competence at much of anything, even at political manipulation, and doesn't have the confidence of the public, but it can still prevent large sums from going to real rivals. NASA will instead try to get any development money pipelined to the big aerospace outfits because NASA knows they aren't much real competition.

But we all know that NASA, having spent billions since the Columbia disaster without any visible return on that investment, isn't going to get us to space. Sometimes some NASA teams can still do things right. Sometimes. But no one can count on that any longer.

http://www.chron.com/cs/CDA/ssistory.mpl/editorial/outlook/3295555

NASA's greatest risk is to give in to timidity in space
Wrong to retreat from giant leaps to tentative baby steps
By EUGENE F. KRANZ

To read and listen to the coverage about the space shuttle, you would think NASA's mission team has taken careless risks with the lives of the seven astronauts who went into space on the Discovery last week.

During the launching, foam fell off the external tank. For the risk-averse, the only acceptable thing to do now is retire the shuttle program immediately and wait for the divine arrival of the next generation of spacecraft. I am disgusted at the lack of courage and common sense this attitude shows.

All progress involves risk. Risk is essential to fuel the economic engine of our nation. And risk is essential to renew American's fundamental spirit of discovery so we remain competitive with the rest of the world.

My take on the current mission is very straightforward. The shuttle is in orbit. To a great extent mission managers have given the spacecraft a clean bill of health. Let us remember that this is a test flight. I consider it a remarkably successful test so far.

The technical response to the Columbia accident led to a significant reduction in the amount of debris striking this shuttle during launching. Mission managers have said that the external tank shed 80 percent less foam this time than on previous launchings. Only in the news media, apparently, is an 80 percent improvement considered a failure. Rather than quit, we must now try to reduce even more the amount of foam that comes off the tank.

The instruments and video equipment developed to assess the launching and monitor debris falling from the tank worked superbly. For the first time, the mission team knows what is happening, when it is happening and the flight conditions under which it occurred. This was a major mission objective, and it is an impressive achievement.

Having spent more than three decades working in the space program, I know that all of the flights of the early days involved some levels of risk. Some of those risks, in hindsight, seem incomprehensible by today's timid standards.

If we had quit when we had our first difficulties in Project Mercury, we would have never put John Glenn on the Atlas rocket Friendship 7 in 1961. Two of the previous five Atlas rockets test-fired before Friendship 7 had exploded on liftoff.

On Gemini 9, 10 and 11, all in 1966, we had complications with planned spacewalks that placed the astronauts at risk. Rather than cancel the walks, we faced the risks and solved the problems. These set the stage for Gemini 12 later that year, during which Buzz Aldrin spent more than five hours outside the capsule and confirmed to NASA that spacewalks could be considered an operational capability.

Eventually, this ability enabled astronauts to retrieve satellites and repair and maintain the Hubble space telescope; and during the current mission, spacewalks were used to repair a gyroscope on the International Space Station and allowed the crew to fix some of the damage that occurred during the launching. These are the rewards for the risks we took on those early Gemini flights.

I understand the tragedy inherent in risk-taking; I witnessed the fire aboard Apollo 1 in 1967 that killed three crew members. It filled us with anger at ourselves and with the resolve to make it right. After the fire we didn't quit; we redesigned the Apollo command module. During the Apollo missions that followed, we were never perfect. But we were determined and competent and that made these missions successful.

I see the same combination of anger, resolve and determination in the space shuttle program today. These people are professionals who understand risk, how to reduce it and how to make that which remains acceptable.

Most important, the current mission has demonstrated the maturity of the shuttle team that endured the Columbia disaster and had the guts to persevere. This is the most important aspect of the recovery from the Columbia accident, and is a credit to the great team NASA now has in place, headed by its administrator, Michael Griffin.

There are many nations that wish to surpass us in space. Does the "quit now" crowd really believe that abandoning the shuttle and the International Space Station is the way to keep America the pre-eminent space-faring nation? Do they really believe that a new spacecraft will come without an engineering challenge or a human toll?

The path the naysayers suggest is so out of touch with the American character of perseverance, hard work and discovery that they don't even realize the danger in which they are putting future astronauts — not to mention our nation.

Kranz, author of "Failure Is Not an Option: Mission Control From Mercury to Apollo 13 and Beyond," is a former Apollo flight director.

So now instead of going back to the old foam that worked they are still experimenting with another new foam that doesnt work either, endangering the lives of the astronauts. Crazy. Completely nuts. Especially since the flight they are on now is so important.

They should indeed go back to the old bonding techniques. Columbia's loss ultimately is the result of the insanity of the bureaucratic mindset. Was no one at NASA man enough to call the EPA requirements absolutely crazy? Think about it. they are what, at most 4 launches per year? What amount of damage could that amount of freon based adhesives have done to the f**king fragile ozone layer? the Freon - ozone link hasn't been proven definitively anyway Whatever leftist at the EPA that pushed the decision on NASA should be hung. It makes as much sense as forcing Ferrari to have pollution controls (wow, what about 400 Ferrari's a year are produced... that will really help the environment making them have pollution control. Most government is a waste and irrational. I absolutely despise the bureaucratic mindset. I pray all bureaucrats go to Hell.

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