Materials International Space Station Experiment (MISSE): Results
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Results
MISSE,
which is a passive experiment that does not rely on mechanical or electronic
parts, has been operating nominally since it was installed during mission
7A.1. However, photos taken in January 2002 indicate that one of the samples
may be peeling off its tray.
The
crew took photos of the passive experiment carrier (PEC) during an EVA conducted
by Carl Walz and Dan Bursch February 20. Scientists on the ground will examine
the photos and determine what, if any, steps should be taken to fix the
problem.
Previous
experiments that exposed materials to the space environment have yielded
information that has helped scientists design better building materials.
For example, the Evaluation of Space Environment and Effects on Materials
study (STS-85) tested thin films of phenylphosphine oxide-containing
polymers. The results showed that when the films were exposed
to atomic oxygen, they formed a phosphate barrier that protected the
films from further attacks by atomic oxygen. The films exhibited
less linear erosion after space flight than most organic polymers.
Silicones flown in low Earth orbit on the Long Duration Exposure Facility
and Mir have helped researchers at NASA Glenn Research Center
create predictive models to explain contamination and oxidation caused
by atomic oxygen. Glenn researchers have also found that Metalized
Teflon fluorinated ethylene propylene (FEP), a common thermal-control
material, degrades from extended radiation exposure in low Earth orbit.
The aluminized-FEP exterior layer on the Hubble Space Telescope has
become brittle, with cracks forming on all sides of the telescope.
MISSE will help designers, like those building the Next Generation Space
Telescope, avoid materials that may develop problems after long-term
exposure to space.
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Applications
The
materials used to build spacecraft must be able to endure incredibly harsh
conditions, such as radiation, vacuum, atomic oxygen, extreme heat and
cold – even space debris. If a material becomes too stressed, it can
cause hardware to break or the a spacecraft hull to breech. Accidents
like this are expensive and time-consuming to repair and can result in
mission failure, injury, or worse. MISSE is a safe way to make sure
that materials can withstand the rigors of space travel. The experiment
data will also help researchers develop new and better materials. Materials
that ensure successful space exploration can also be used on Earth to design
equipment and structures, like aircraft, submarines, and fire safety equipment,
that protect people in extreme environments. The results from MISSE
can also make everyday consumer products, like paints and plastics, more
sun- and weather-resistant.
Web Sites
Materials International Space Station Experiment (Langley Research Center)
