Astronauts Steve Smith and John Grunsfeld service the Hubble Space Telescope during a repair mission last December on shuttle mission STS-103. Photo: NASA/JSC

The Hubble Space Telescope team at NASA's Goddard Space Flight Center in Greenbelt, Md., has partnered with a private-industry manufacturer to rigorously test and flight qualify a carbon coating that is critical to the successful operation of a new piece of Hubble hardware.

Goddard's Hubble Project and Surmet Corporation in Burlington, Mass., put the diamond-hard coating, which the company calls UltraC Diamond(TM), through a rigorous test program to verify it could operate in the extremes of space. The coating covers tiny parts of an experimental cryogenic cooler, or "cryocooler," that will be attached onto Hubble's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) during a servicing mission in 2001. The cryocooler cools the detectors in the instrument and maintains them at 70 degrees Kelvin. This infrared instrument has been dormant since exhausting its supply of nitrogen ice in 1999. The cryocooler will restore NICMOS to full operation and extend its useful life.

"This new coating virtually eliminates wear and tear on moving parts," said Frank Cepollina, Manager of NASA's Hubble Space Telescope Development Project. "It has enormous potential for U.S. manufacturing -- especially in high tech, rotating machinery such as high speed turbines and pumps. The new coating also has many medical uses, such as in heart pumps and artificial hips and knees."

Tiny bearings and turbine shafts like these are part of a new cooling system for Hubble¹s infrared NICMOS instrument. To minimize friction and wear, shafts and bearings are covered with a slippery, diamond-hard coating approximately 1/100th the thickness of a human hair. These tiny parts are pictured with a dime for size comparison. Photo: NASA/GSFC

During the cryocooler's normal operation, a tiny circulator shaft spins at a speed of 6000 revolutions per second. To minimize friction and wear, the circulator shaft and bearings required a very thin, hard, slippery coating. The film-like UltraC Diamond(TM) coating (approximately 1/100th the thickness of a human hair) has a microscopically uniform structure and the way it is applied enables its use on very small parts with just millionths of an inch between them. The Hubble Project funded extensive testing of the coating to verify its qualification for flight. Use of the coating will mark the material's first space use on titanium and the first use of any hard, carbon coating on such small, complex, and precise machinery.

According to its manufacturer, UltraC Diamond(TM) can be deposited on a wide range of materials, including titanium (heart pump), ceramics, polymers, and prosthetics. The coating functions in a wide range of temperatures, from extremely low to moderately high. The UltraC Diamond(TM) coating is manufactured and applied at the Burlington, Mass. facilities of Surmet Corporation. A technology-based small business, Surmet specializes in developing and commercializing innovative coating technologies.

The next servicing mission is currently scheduled for next year.