Alliant Techsystems has started to assemble the Primary Mirror Backplane Support Structure, or spine, of NASA's James Webb Space Telescope (JWST) at its Magna, Utah, facility.

The Webb Telescope will become NASA's premier observatory following its launch in 2013, serving astronomers worldwide in their mission to investigate the formation and evolution of planets, stars, galaxies, and the early universe.

The 2,200 pound (1,000 kg) backplane will support the telescope's 21-foot diameter (6.5 meter) primary mirror on orbit nearly a million miles from Earth.

The structure is designed for unprecedented thermal dimensional stability performance and is capable of withstanding temperatures as cold as -400 degrees F, ensuring essentially motionless operations for optimum deep space imaging. The backplane will also carry 7,500 pounds (3400 kg) of telescope optics and instruments during launch.

"ATK's Backplane is the first time a composite structure will be used to support an astronomical segmented mirror in space, making it an integral part of the JWST primary mirror and requiring unprecedented dimensional stability performance, at a threefold increase in size," said Kelly Franklin, Vice President and General Manager of ATK Government Space.

Made with advanced graphite composite materials mated to titanium and invar fittings and interfaces, some 9,000 joints must be individually injection-bonded to complete the backplane. ATK will deliver it to prime contractor Northrop Grumman in late 2010 for integration into the Webb Telescope.

While the Hubble Space Telescope has captured mainly visible light images, the Webb Telescope will primarily observe light from faint and very distant objects, using instruments designed to work primarily in the infrared range of the electromagnetic spectrum.

NASA Goddard Space Flight Center (GSFC) manages the JWST program. ATK is under contract to Northrop Grumman for the engineering, design, fabrication, and testing of the Webb Telescope's composite components and subsystems.