It’s hard to believe that anything could have been done cheaply to save costs on the NASA space shuttle. Yet that appears to be exactly the case with the insulation problems that have been plaguing recent flights. On Friday, cracked insulation was found on all three of the fuel tanks scheduled for upcoming flights. And the cracks have probably been there a while.
Cracks are appearing in foam-covered cork insulation that is applied to aluminum alloy brackets. The brackets, which are 17 inches long and four inches wide when foamed, support the liquid oxygen feedline on the external fuel tank. The cork prevents ice from forming on the brackets. Super-cold fuel is inside the tank. Engineers are now finally developing a better solution—replacement of the aluminum alloy with titanium. For the next shuttle flight, the foam and high-density cork insulation will be removed and replaced with foam only. The titanium parts will be ready by spring.
Bad materials engineering has been one of the banes of the space shuttle program. And the problems have not exactly been rocket science. The most famous, or course, was the O-ring failure that led to the disintegration of the Challenger in 1986. It was well known that the fluoroelastomeric materials in the O-rings had extremely poor low-temperature capabilities. Once compressed, very cold O-rings take time to return to their normal shape. Temperatures were very cold the night before the Challenger launch, but temperatures at launch time were within allowable guidelines. Because of poor communications, the problems with the O-ring materials’ properties were not adequately known, and the launch proceeded. O-ring joints now have on-board heaters that are turned on when temperatures drop below 50F.
Dow Chemical and several other companies have launched a program in Omaha, Neb. to divert about 36 tons of plastics from landfills in its first phase, and convert it into energy used for cement production.
A make-your-own Star Wars Sith Lightsaber hilt is heftier and better-looking than most others out there, according to its maker, Sean Charlesworth. You can 3D print it from free source files, and there's even a hardware kit available -- not free -- so you can build one just in time for Halloween.
Some next-generation bio-based materials are superior in performance to their petro-based counterparts, but also face some commercial challenges. This is especially true of certain biopolymers, adhesives, coatings, and advanced materials.
Cars and other vehicles, as well as electronics and medical devices, continue to lead the use cases for the new plastics products we've been seeing, as engineers design products for tougher environments.
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