Northrop Grumman and its partner ATK have completed static testing of the primary mirror backplane support structure (PMBSS) for NASA’s James Webb Space Telescope
The static testing demonstrates that the backplane has the structural integrity to withstand the forces and vibrations of launch, and is the final test prior to starting the integration of the backplane with the rest of the telescope.
The support is one of the most lightweight structures ever designed and built. It is the stable platform that will hold the telescope’s science instruments and the 18 beryllium mirror-segments that form the 21-foot-diameter primary mirror nearly motionless while the telescope peers into deep space.
Northrop Grumman is under contract to NASA’s Goddard Space Flight Centre in Greenbelt, Maryland, and heads up the industry team that designs and develops the Telescope’s optics, sunshield and spacecraft. ATK designed, engineered and manufactured the more than 10,000 parts of the entire structure at its facilities in Magna, Utah. They used composite parts, lightweight graphite materials, contemporary material sciences and advanced fabrication techniques to build the structure.
Scott Texter, Webb optical telescope element manager, Northrop Grumman said;
This is the largest, most complex cryogenically stable structure humans have ever built. Completion of the static testing verifies that it can hold the weight it is designed to hold. Now the structural backbone of the observatory is officially verified and ready for integration.
In Autumn last year the structure underwent extreme cryogenic thermal testing at Marshall Space Flight Centre in Huntsville, Alabama. Next, Northrop Grumman will integrate the composite structures with the deployment mechanisms to create the overall optical telescope element structure, which will then be shipped to NASA Goddard for integration with the mirrors. NASA and Northrop Grumman will continue cryogenic testing of the PMBSS structure after mirror integration is complete.