WELCOME INSTAPUNDIT READERS! (... and thanks, Glenn)
Also many thanks to the others who have linked and tracked back to this post. Your links and comments are appreciated.
More information in this post as well.
Here's a link to my Shuttle news roundup, updated daily.
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The New York Times reports that NASA has officially announced that the Space Shuttle will be grounded indefinitely - until they figure out how to keep the exterior foam insulation from peeling off the gigantic fuel tank that is the main piece of the Shuttle's launch assembly.
The Columbia and its crew were lost because a 1.67-pound piece of
insulating foam that had fallen off the external tank during liftoff
crashed through the leading edge of the shuttle's left wing. The
resulting hole admitted superheated gases during the shuttle's fiery
re-entry into the atmosphere on Feb. 1, 2003.
That chunk fell from an area of hand-applied foam called the bipod
arm ramp. The ramp's insulating foam surrounded the struts connecting
the tank to the orbiter, and were originally designed to prevent ice
from forming and becoming a debris hazard. But NASA had noticed that
the bipod arm ramp tended to shed foam and decided to redesign it. They
planned to replace it after the Columbia flight.
... In the incident described here on Wednesday, the new piece of foam - a
hat-shaped chunk as much as 33 inches across at the widest part and 14
inches at the narrow part - sheared off another ramp on the external
tank. It is known as the protuberance air load ramp, which NASA
abbreviates as the PAL ramp, and was designed to minimize crosswise
airflow and turbulence around cable trays and lines used to pressurize
the external tank. The new piece is slightly smaller than the
briefcase-size piece that hit the Columbia, Mr. Hale said.
... Mr. Parsons and Mr. Hale said there were other surprising examples of
lost foam - including divots several inches long that popped out of
"acreage foam," which is applied robotically and had been considered to
be free of shedding problems.
But here is what no one seems to be talking about - the problems with foam peeling and breaking off the main fuel tank are relatively new. In 1997, NASA bent to pressure from environmental groups and began using a new type of foam on the main fuel tank.
Why all the fuss? Because the traditional foam insulation, the product that had been specified in the 1970 Shuttle designs, the product that was used up until 1997, was made by injecting polymer with chlorofluorocarbons -- "freon" -- compounds whose use was severely limited under the 1991 Montreal Protocol. With the adoption of this protocol by the U. S., the Environmental Protection Agency set target dates for major industries to phase out the use of freon.
After the new foam was used on Columbia mission STS-87 in November 1997, post-flight examination of the craft found that 308 of the special heat-absorbent ceramic tiles that cover the Shuttle's outer skin were damaged. The average number of damaged tiles for previous missions was 40. NASA engineers immediately suspected that the new insulating foam was breaking loose, but NASA supervisors were apparently more interested in impressive, successfully-completed missions than in adequate mission safety. The peeling foam was written off as a negligible risk.
The irony of this is that in 2001, the EPA exempted NASA from enforcement of its freon regulations because an audit determined that the amount of freon used by NASA was minuscule. But apparently NASA was more concerned with public relations and with making sure that their policies received a nod of approval from environmental groups. NASA's official report on the Columbia disaster cited a change in the foam application process -- and not the change in the foam itself -- as the most sensible reason for the foam to start peeling off.
When the Rogers Commission released their official report on the
Challenger disaster in 1987, there was one member of the panel who did
not sign it. That person was Noble laureate physicist Richard P.
Feynman. He released his own statement after the commission's hearings were published, which concluded,
For a successful technology, reality must take precedence over public
relations, for nature cannot be fooled.
Environmentalists, maybe, but certainly not the laws of physics.
Hopefully NASA will reconsider Dr. Feynman's timeless observation
again as they try to solve the problem of peeling CFC-free Space
Shuttle fuel tank foam.
Either that, or maybe they could think about investing their time
and energy in a space vehicle that is not dependent on 30-year-old
technology, and that actually costs less to operate than an a roughly
equivalent but non-reusable payload-carrying vehicle. That would be
real progress.
...
Here's more on this subject in an August 2004 post by Paul at WizBang.
Sissy Willis was having trouble tracking back here, so Sissy, here is a link to your related post. If you haven't read her excellent writing or shared in her cat fancies,then you should check out her blog.
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