NASA Selects Material for Orion Spacecraft Heat Shield

HOUSTON, April 7 /PRNewswire-USNewswire/ -- NASA has chosen the material for a
heat shield that will protect a new generation of space explorers when they
return from the moon. After extensive study, NASA has selected the Avcoat
ablator system for the Orion crew module.

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Orion is part of the Constellation Program that is developing the country's
next-generation spacecraft system for human exploration of the moon and
further destinations in the solar system. The Orion crew module, which will
launch atop an Ares I rocket, is targeted to begin carrying astronauts to the
International Space Station in 2015 and to the moon in 2020.

Orion will face extreme conditions during its voyage to the moon and on the
journey home. On the blistering return through Earth's atmosphere, the module
will encounter temperatures as high as 5,000 degrees Fahrenheit. Heating rates
may be up to five times more extreme than rates for missions returning from
the International Space Station. Orion's heat shield, the dish-shaped thermal
protection system at the base of the spacecraft, will endure the most heat and
will erode, or "ablate," in a controlled fashion, transporting heat away from
the crew module during its descent through the atmosphere.

To protect the spacecraft and its crew from such severe conditions, the Orion
Project Office at NASA's Johnson Space Center in Houston identified a team to
develop the thermal protection system, or TPS, heat shield. For more than
three years, NASA's Orion Thermal Protection System Advanced Development
Project considered eight different candidate materials, including the two
final candidates, Avcoat and Phenolic Impregnated Carbon Ablator, or PICA,
both of which have proven successful in previous space missions.

Avcoat was used for the Apollo capsule heat shield and on select regions of
the space shuttle orbiter in its earliest flights. It was put back into
production for the study. It is made of silica fibers with an epoxy-novalic
resin filled in a fiberglass-phenolic honeycomb and is manufactured directly
onto the heat shield substructure and attached as a unit to the crew module
during spacecraft assembly. PICA, which is manufactured in blocks and attached
to the vehicle after fabrication, was used on Stardust, NASA's first robotic
space mission dedicated solely to exploring a comet, and the first sample
return mission since Apollo.

"NASA made a significant technology development effort, conducted thousands of
tests, and tapped into the facilities, talents and resources across the agency
to understand how these materials would perform on Orion's five-meter wide
heat shield," said James Reuther, the project manager of the study at NASA's
Ames Research Center at Moffett Field, Calif. "We manufactured full-scale
demonstrations to prove they could be efficiently and reliably produced for
Orion."

Ames led the study in cooperation with experts from across the agency.
Engineers performed rigorous thermal, structural and environmental testing on
both candidate materials. The team then compared the materials based on mass,
thermal and structural performance, life cycle costs, manufacturability,
reliability and certification challenges. NASA, working with Orion prime
contractor Lockheed Martin, recommended Avcoat as the more robust, reliable
and mature system.

"The biggest challenge with Avcoat has been reviving the technology to
manufacture the material such that its performance is similar to what was
demonstrated during the Apollo missions," said John Kowal, Orion's thermal
protection system manager at Johnson. "Once that had been accomplished, the
system evaluations clearly indicated that Avcoat was the preferred system."

In partnership with the material subcontractor, Textron Defense Systems of
Wilmington, Mass., Lockheed Martin will continue development of the material
for Orion. While Avcoat was selected as the better of the two candidates, more
research is needed to integrate it completely into Orion's design.

For more information about the Orion crew module, visit:
http://www.nasa.gov/orion

For more information about the Constellation Program, visit:
http://www.nasa.gov/constellation

SOURCE NASA

Ashley Edwards, ashley.edwards-1@nasa.gov, or Grey Hautaluoma,
grey.hautaluoma-1@nasa.gov, Headquarters, Washington, +1-202-358-1756, or
+1-202-358-0668, or Kylie Clem, Johnson Space Center, Houston,
+1-281-483-5111, kylie.s.clem@nasa.gov, all of NASA