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More on Shuttle Foam Damage from STS-87

This NASA page has notes by a NASA worker from 1997 about the “significant damage” done to STS-87 from the reformulated, Freon-free foam insulation flaking off during the Shuttle’s ascent (emphasis added),

During the STS-87 mission, there was a change made on the external tank. Because of NASA’s goal to use environmentally friendly products, a new method of “foaming” the external tank had been used for this mission and the STS-86 mission. It is suspected that large amounts of foam separated from the external tank and impacted the orbiter. This caused significant damage to the protective tiles of the orbiter. Foam cause damage to a ceramic tile?! That seems unlikly, however, when that foam is combined with a flight velocity between speeds of MACH two to MACH four, it becomes a projectile with incredible damage potential. The big question? At what phase of the flight did it happen and what changes need to be made to correct this for future missions? I will explain the entire process.

And intriguing comments about similar issues during STS-86,

The STS-86 mission revealed a similar damage pattern but to a much lesser degree than STS-87. The STS-86 tile damage was accepted ruled as an unexplained anomaly because it was a night launch and did not provide the opportunity for the photographic evidence the STS-87 mission did. A review of the records of the STS-86 records revealed that a change to the type of foam was used on the external tank. This event is significant because the pattern of damage on this flight was similar to STS-87 but to a much lesser degree. The reason for the change in the type of foam is due to the desire of NASA to use “environmentally friendly” materials in the space program. Freon was used in the production of the previous foam. This method was eliminated in favor of foam that did not require freon for its production. MSFC is investigating the consideration that some characteristics of the new foam may not be known for the ascent environment.

Reporting from the Intersection of Christianity and Capitalism

Jeremy Lott has a fascinating report about the comingly of commerce and religion with a long, excellent piece reporting on the Christian Booksellers Association convention. I especially liked his concluding paragraphs, which echoed similar sentiments aired by Paul Freund in another brilliant Reason essay about the “culture industry.” Lott writes,

Are many of these products merely a way to make a fast and cynical buck? They probably are. But the more revealing question is not about what the products do for their producers; it is about what they may be doing for their consumers.

The anti-materialistic/anti-consumerist criticism overlooks an essential fact: that material artifacts, even kitsch, can embody real meaning for those who use them.

The products, good and bad, that dominated the CBA both reflected and validated the subculture that generated the demand for them. The people who read the books, listen to the music, hang the Thomas Kinkade paintings in their homes, and use the other products of this industry are surrounding themselves with artifacts that reflect their values and beliefs, that validate who they are. For such consumers, the Left Behind novels, the evangelical pop music, and all the rest serve as the building blocks of a shared evangelical cultural identity. In brief, evangelicals are using the market to fashion and refashion themselves, and to project the resulting identity to others, in just the way that all consumers do.

EPA vs. Space Shuttle?

In the wake of the Challenger disaster there was a myth spread by some conservatives that went like this: the sealant used on the O-rings that failed was changed from an asbestos-formulated sealant to a non-asbestos version. Hysteria over asbestos, therefore, led directly to the Challenger disaster.

This turns out to be less than accurate, and made me suspicious when someone on a mailing list I read posted that environmentalists had forced a changed in the foam insulation sprayed on the shuttle’s external fuel tank. The reformulated spray-on insulation, so the story goes, was known to have problems with flaking — exactly the problem that seems likely to have caused the recent Columbia disaster.

Unlike the Challenger/asbestos claim, however, this one seems to actually have some basis in fact. A 1999 NASA press release on the matter has been yanked off the web, but is still available thanks to Google. Here’s the full text (emphasis added),

DRYDEN F-15B SUPPORTS SHUTTLE EXTERNAL TANK INSULATION TESTS
January 28, 1999
Release: 99-1
Flight tests at the NASA Dryden Flight Research Center, Edwards, Calif., recently demonstrated that a new type of insulation foam used on the Space Shuttle’s giant external tank remains intact under some of the dynamic environments seen during the initial stage of the Shuttle’s ascent.

Mimicking a Space Shuttle launch profile, an F-15B research aircraft based at NASA Dryden flew a series of missions to evaluate the dynamic response characteristics of the new insulation material. The Shuttle External Tank Experiment involved six research flights over a two-week period by Dryden’s F-15B in partnership with NASA’s Marshall Space Flight Center, Huntsville, Ala., and the Michoud Assembly Facility near New Orleans, La.

“This experiment was a perfect example of the versatility of the F-15B and its Flight Test Fixture,” said Dave Richwine, Dryden’s F-15B project manager. “It shows how we can customize our capability for any particular experiment’s requirements.”

The experiment was part of an effort to determine why small particles of spray-on foam insulation flaked off of the inter-tank section of the external fuel tank on Space Shuttle mission STS-87 as the Shuttle ascended. The new lightweight insulation material was developed to comply with an EPA mandate to reduce ozone-depleting chemicals released into the atmosphere. Although such flaking or erosion of the insulation off the external tank posed no safety hazard to the Shuttle or its crew, engineers wanted to determine its cause to prevent future maintenance and operational problems. The flights aboard Dryden’s F-15B were just one of many tests to which the new insulation material is being subjected.

Initial results of the flight tests at Dryden, which were designed to replicate the pressure environment the Shuttle encounters in the first 65 seconds after launch, indicate the new foam survived the tests in perfect shape, with no evidence of flaking or erosion found.

For the tests on Dryden’s F-15B, test panels covered with the foam insulation were mounted on the left side of the Flight Test Fixture that is carried underneath the aircraft’s center fuselage. Six different panel configurations were flown one on each flight. Five of the panels were covered with the insulation now used on the sidewalls of the Shuttle’s external tank, while one was covered with an alternate formulation of slightly higher density that is used on the dome atop the tank. While several panels were left in wavy as-sprayed configurations, others were finely machined to duplicate the thrust panel rib structure of the thrust panels where the solid rocket boosters are attached to the new “super-lightweight” external tanks now flown on Shuttle missions. Four panels had the ribs aligned with the airflow, while two others had the ribs mounted vertically in order to simulate the complex airflow around the Shuttle and its external tank during its ascent.

On each flight, Dryden research pilot Dana Purifoy flew the F-15B through a series of side-to-side yaw maneuvers beginning at 7,300 feet altitude. He then increased speed and altitude in a stair-step approach, finally zooming up to 61,000 feet at speeds of up to Mach 1.5 (1.5 times the speed of sound) before descending for landing.

“It was important that the F-15B could match part of our (shuttle launch) profile, and it does a fantastic job of doing that,” said aerodynamicist Roy Steinbock of Lockheed-Martin Michoud Space Systems, staff engineer on the experiment.

“Our main goal was to try to match the dynamic pressure history (that the external tank encounters during a shuttle launch). The Dryden F-15B can match the high-altitude, low-pressure environment that the Shuttle encounters, and can test a multitude of Mach numbers in (one) flight. That’s something we cannot do anywhere else–we can’t replicate that in a wind tunnel.”

“Marshall’s objectives included flying at Mach 1.5, reaching 60,000 feet and completing six research flights in two weeks,” added Richwine. “We were proud to be able to meet Marshall’s performance and schedule objectives for this experiment.”

“The successful completion of the tests at Dryden, along with wind tunnel testing at the Arnold Engineering Development Center in Tullohoma, Tenn., hot gas testing at Marshall and a multitude of other tests, has given us additional data to further improve the foam insulation on the Space Shuttle’s External Tank,” said Parker Counts, Marshall’s Space Shuttle External Tank program manager. “This was a fine example of the team work between NASA centers and other government agencies.”
–nasa–
NASA Dryden Flight Research Center
Public Affairs Office
Edwards, CA 93523
(661) 276-3449
FAX (661) 276-3566

The line about the flaking posing no risk to the shuttle itself is downright eerie.

CDC Reports on Two Vegan Children Who Suffered from B-12 Deficiencies

The U.S. Centers for Disease Control and Prevention reported in January on the case of two infants who suffer from brain abnormalities due to a B-12 deficiency in the diets of their vegan mothers.

The main source of B-12 for most people is meat, dairy products and eggs. Vegan and vegetarian diets tend to be deficient in B-12 and most responsible vegan and vegetarian literature notes this fact and offers guidance on how to ensure and adequate supply of this important nutrient.

The CDC’s Dr. Maria Elena Jefferds reported on the two infants in the January 31st issue of the CDC’s Morbidity and Mortality Weekly Report. Jefferds describes the first case,

During August 2001, a girl aged 15 months was hospitalized for lethargy and failure to thrive. She was born after a full-term pregnancy complicated by prolonged nausea and vomiting. She was breastfed for 8 months, but the extent (exclusivity) of breast milk consumed relative to other food was unknown. Her mother reported following a vegan diet during the preceding 7 years and took nutritional and vitamin supplements. The cobalamin content of the supplements was unknown. When the child was aged approximately 8 months, organic whole-grain cereals and fruit shakes were introduced, but she had a poor appetite and vomited regularly. Her parents became concerned about her growth and development, and she was evaluated by a pediatrician at age 15 months. The pediatrician diagnosed failure to thrive, developmental delay, and severe macrocytic anemia. The child was hospitalized, and cobalamin deficiency was diagnosed (marked elevation [not quantified] of urine methylmalonic acid; serum B12:100 pg/mL.

And the second case,

During March 2001, a boy aged 30 months with failure to thrive and mild global developmental delays was taken to a genetics clinic. He was born after a full-term pregnancy and breastfed exclusively until age 9 months. The mother reported following a vegetarian diet during the preceding 20 years, with negligible amounts of meat, fish, and dairy products. She reported intermittent intake of a vitamin supplement (TwinLab® Stress B Complex Caps, containing 250 mcg of “cobalamin concentrate,” according to the label). When the boy was age 9 months, the health-care provider and his parents became concerned about the child’s growth and development (Table 1). His diet was supplemented with fruit and dry cereals to improve growth. When this was unsuccessful, he underwent a frenectomy at age 11 months to free tongue movements and improve coordination of swallowing and chewing. Despite this intervention, growth was inadequate. His diet was supplemented with soy- and cow’s milk–based formulas. He tolerated neither and started a multigrain nondairy formula (Multigrain Milk®) in addition to fruit, vegetables, chicken, an unknown vitamin supplement, and a product called Greens Plus® (no cobalamin content listed on label). Because of poor motor and speech development at age 11 months, the child was evaluated by a developmental pediatrician, who ordered genetic and metabolic studies and prescribed speech, occupational, and physical therapies. The child had persistent elevation of urine methylmalonic acid on three occasions but received no treatment for cobalamin deficiency until after the third measurement, which was ordered for a genetics clinic evaluation.

The CDC report noted that the prevalence of B-12 deficiency in children under 4 is not known and, “No clinical practice guidelines exist for diagnosing cobalamin deficiency in young children” since said deficiency results in a number of nonspecific symptoms such as lethargy and deficient growth.

The CDC recommended that,

Health-care providers should be vigilant about the potential for cobalamin deficiency in breastfed children of vegetarian mothers. Potential cobalamin deficiency should be included in the differential diagnosis when assessing young children of vegetarian mothers who have symptoms consistent with cobalamin deficiency, including failure to thrive, developmental delay, neurologic/psychiatric manifestations, and hematologic abnormalities (4).

Health-care providers who care for mothers in the preconceptional, prenatal, and postpartum periods and their young children should ask pregnant and lactating mothers about their diets to identify those who are vegetarians. Pregnant and lactating women should eat foods rich in cobalamin or take a daily supplement containing at least the recommended dietary intake of cobalamin (Table 2). For those eating no or very limited food of animal origin or a known cobalamin source, a cobalamin assessment is indicated. If lactating mothers are cobalamin deficient, their infants should be evaluated for cobalamin deficiency and treated appropriately.

Of course more research into pregnant vegan and vegetarian women might also be helpful, but such research is often attacked as little more than an attempt to undermine vegan and vegetarian diets (such as Jeff Nelson’s tirade against the very thought of funding research to examine choline deficiencies in pregnant vegetarian and vegan women).

Sources:

Babies’ mental delay tied to moms’ vegan diet. Alison McCook, Reuters, January 30, 2003.

Neurologic Impairment in Children Associated with Maternal Dietary Deficiency of Cobalamin — Georgia, 2001. Morbidity and Mortality Weekly Report, Centers for Disease Control, 52(04);61-64.

EU Pig Toy Hoax Story

Reports recently circulated on the Internet and in some newspapers that British farmers would soon be required by the European Union to supply their pigs with toys or else face fines of up to 2,500 pounds. As reported by Reuters, for example, the EU directive supposedly required farmers to “put a football, metal chains or hay in their pigsties.”

Both British and EU officials deny the story, however, and report that nowhere in the EU directive is any mention made of footballs or any toys. The directive does require farmers to supply pigs with rooting materials such as straw, hay, wood, sawdust, compost or peat.

The misunderstanding seems to have started with the UK Department of the Environment, Food and Rural Affairs whose announcement of the new regulations related to pigs led some observers to believe that the directive required the use of toys. A spokesman for DEFRA was quoted in some news stories as saying,

While straw and hay would do, obviously the use of a football or a chain would also do. For many years now vets have been suggesting that you put a football or something to kick around into the stall with a horse if it is restless. Basically, the same is true for pigs. If you put in a football or you dangle a chain they could nose it around and play with it, it is helpful.

This interpretation of the EU directive seems to rest solely with DEFRA.

Sources:

Pig toy tale ‘anti-Europe rubbish’. CNN, January 29, 2003.

Pigs can go hog wild with new toys. Reuters, February 1, 2003.

Foodborne Illnesses from Fruits and Vegetables on the Rise

While foodborne illnesses such as E. coli are usually associated with meat eating, the American Phytopathological Society reports that the incidence of foodborne disease related to fruit and vegetable consumption is on the rise.

According to the plant pathologist J.W. Buck, the annual number of produce-related food disease outbreaks doubled between 1973-1987 and 1988-1992 and continue to rise. The outbreaks include,

Pathogen Product
Aeromonas alfalfa sprouts, asparagus, broccoli, cauliflower, celery, lettuce, pepper, spinach
Bacillus cereus alfalfa sprouts, cress sprouts, cucumbers, mustard sprouts, soybean sprouts
Campylobacter jejuni green onions, lettuce, mushroom, potato, parsley, pepper, spinach
Clostridium botulinum cabbage, mushrooms, pepper
E. coli O157:H7 alfalfa sprouts, apple juice, cabbage, celery, cilantro, coriander, cress sprouts, lettuce
Listeria monocytogenes bean sprouts, cabbage, chicory, cucumber, eggplant, lettuce, mushrooms, potatoes, radish, salad vegetables, tomato
Salmonella alfalfa sprouts, artichokes, beet leaves, celery, cabbage, cantaloupe, cauliflower,
chili, cilantro, eggplant, endive, fennel, green onions, lettuce, mungbean
sprouts, mustard cress, orange juice, parsley, pepper, salad greens,
spinach, strawberries, tomato, watermelon
Shigella celery, cantaloupe, lettuce, parsley, scallions
Staphylococcus alfalfa sprouts, carrot, lettuce, onions sprouts, parsley, radish
Vibrio cholerae cabbage, coconut milk, lettuce

Among the large outbreaks, an E. coli outbreak in Japan in 1996 affected 4,000 school children and killed four. The source of the outbreak was traced back to radishes. In the United States 1995-1998 saw nine separate outbreaks of Salmonella or E. coli traced back to contaminated sprouts.

Why the increase? Part of the reason is due to good news on the nutrition front — people are simply eating more fruits and vegetables. From 1988 to 1996, per capita consumption of fruits and vegetables in the United States increased by 20 pounds. With the increase in consumption, the amount of fruits and vegetables imported from abroad has increased while methods of storage and processing have changed as well.

Unfortunately, according to the American Phytopathological Society, while there is an apparatus in place to inspect meat and reduce the risk of foodborne pathogens, there is no parallel system in place for inspecting fruits and vegetables.

Sources:

More people are getting sick from eating fresh fruits. American Phytopathological Society, Press Release, January 27, 2003.

Recent Trends in Microbiological Safety of Fruits and Vegetables. J.W. Buck, R.R. Walcott, L. R. Beuchat, Plant Health Progress, Jan./Feb. 2003.