REDONDO BEACH, Calif., May 15, 2006 (PRIMEZONE) -- A Northrop Grumman Corp. (NYSE:NOC) team successfully completed a series of stringent tests that proved a key element of the James Webb Space Telescope (JWST) can function successfully in its planned space environment. Northrop Grumman is prime contractor for JWST and leads the telescope's overall system design and development effort under contract to NASA's Goddard Space Flight Center.
The tests were conducted on JWST's sunshield membrane, a five-layer structure approximately the size of a tennis court. The sunshield will block solar light and keep the observatory operating at cryogenic temperatures, enabling its infrared sensors to see distant galaxies, early stars, planetary systems and help astronomers better understand dark matter.
Passing the tests demonstrated that the membrane has achieved Technology Readiness Level (TRL) 6. TRL is a measure used by the U.S. government to assess the maturity of evolving technologies; a level 6 rating means a system has been tested successfully in a relevant operational environment. While engineering development and testing will continue for the next three years, this milestone concludes all basic technology development required for the sunshield.
A series of 26 exacting tests was performed at facilities across the country, starting in 1999 and concluding late last year. The tests, which measured the performance of the membrane and its coatings, simulated conditions at the L2 Lagrange point nearly one million miles from Earth, where JWST will operate.
"We're inventing new testing and manufacturing techniques to ensure the sunshield membrane does its mission-critical job of keeping the JWST instruments and telescope at cryogenic temperatures," said Martin Mohan, JWST program manager for Northrop Grumman Space Technology. "It is a tribute to our strong working relationships with our government, business and academic partners that these rigorous tests were so successful."
Each sunshield membrane layer is about as thick as a human hair (one to two-thousandths of an inch thick) and is made of a polymer-based film, DuPont(tm) Kapton(r) E. The fabrication of the sunshield membranes is performed by Newport Beach, Calif.-based SRS Technologies at their Huntsville, Ala., facility and integrated with the sunshield at Northrop Grumman's Space Park facility in Redondo Beach, Calif. The layers are separated from each other and held in place by deployable booms.
During JWST's five to ten-year mission, the membrane will be subject to bombardment from micro-meteoroids similar to very fine sand particles and several different types of radiation. It will have to resist abrasion, tension, tearing and cracking, all at extreme temperatures that range from 400 K (260 F) to 30 K (-406 F).
A significant challenge was locating, modifying, or in some cases, creating equipment or testing methods that would accurately measure the exacting performance standards set for the membrane. Because no existing equipment was able to apply very low-energy proton radiation bombardment, Northrop Grumman worked with scientists at the University of Dayton Research Institute at Wright-Patterson Air Force Base, Ohio, to modify a low-energy proton gun used for tests.
Micro-meteoroid impact tests were conducted at Auburn University's Hypervelocity Impact Facility in Auburn, Ala. To run samples at cryogenic temperatures, engineers modified existing equipment and added a cryogenic cooler, which was donated by Marshall Space Flight Center in Huntsville.
There were also manufacturing and materials challenges in applying the silicon coating to the membrane. Northrop Grumman engineers worked closely with the thin-film coating supplier, Sheldahl, Inc. in Northfield, Minn., to make the silicon conductive and modify the coating process to ensure consistency when the silicon is deposited on membrane sheets using a continuous-roll coating process.
JWST will explore far beyond the reach of current telescopes, peering into the near and mid-infrared at great distances to search for answers to astronomers' fundamental questions about the birth and evolution of galaxies, the size and shape of the universe and the mysterious life cycle of matter.
Northrop Grumman Corporation is a global defense company headquartered in Los Angeles, Calif. Northrop Grumman provides technologically advanced, innovative products, services and solutions in systems integration, defense electronics, information technology, advanced aircraft, shipbuilding and space technology. With approximately 125,000 employees and operations in all 50 states and 25 countries, Northrop Grumman serves U.S. and international military, government and commercial customers.