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Is aluminum the best choice for building the bodies of space vehicles? Pure aluminum lacks the tensile strength needed for airplanes and helicopters, but aluminum alloys with magnesium and silicon are materials of choice in spacecraft. Pound for pound, alloys such as aluminum 6061 with T6 temper are stronger than some steel alloys. Aluminum aerospace alloys offer flame and chemical resistance, too.
So why would scientists and engineers consider plastic parts instead? Although aluminum alloys are lightweight – a key consideration in applications where every pound or kilogram counts – they provide relatively little protection against the high-energy cosmic rays that would harm humans on a mission to Mars. High-performance aerospace plastics offer additional benefits as well.
Tissue-Equivalent Plastics (TEP)
Spaceflight exposes travelers to several forms of radiation. Radiation belts around Earth trap charged particles from the Sun, which also erupts in solar flares that release intense radiation. Cosmic rays from objects outside our solar system also bombard spacecraft with high-energy particles. Like solar flares, these cosmic rays can also cause electromagnetic interference (EMI) with spacecraft instruments.
Astronauts with the Apollo program were subjected to only minor doses of radiation because they were outside of Earth’s orbit for just a few days. A manned mission to Mars, or even a long-term stay on the Moon, would require scientists and engineers to develop space vehicles with much more shielding. At the same time, any such “space age” material must all meet all other mission requirements.
According to researchers from the University of New Hampshire and Southwest Research Institute, tissue-equivalent plastics (TEP) have promise. Using observations made by the Cosmic Ray Telescope for the Effects of Radiation (CRaTER), the researchers determined that TEP, which simulates human muscle, provides better shielding than aluminum against radiation in space.
High-Performance Aerospace Plastics
The advantages of high-performance plastics are well-known in the aviation and aerospace industries. Plastics are approximately 50% lighter than aluminum and, unlike other metals, do not corrode. Modern polymers also provide a high degree of design freedom and can be fabricated into custom components. Fiber-reinforced plastics (FRP) offer increased strength and resistance to deformation.
Aerospace manufacturers also use transparent plastics, a lightweight, impact-resistant alternative to glass. Plastics with modified sliding properties are recommended for dry applications under extreme conditions because of their lubrication properties. High-performance aerospace plastics also offer high thermal and mechanical stability, inherent flame resistance, and a low degree of thermal expansion.
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The global aerospace market is growing, and Elasto Proxy will continue to bring you insights about the role of high-quality rubber and plastic components. As a supplier of sealing solutions to the aerospace industry, our custom fabrication capabilities include hatch seals, door and window seals, interior sealing products, and thermal and acoustic insulation for airframes aircraft engines. Keep in touch!