Testing of the James Webb Space Telescope's Center of Curvature Optical Assembly, or COCOA, recently was completed in the X-ray and Cryogenic Test Facility at NASA's Marshall Space Flight Center in Huntsville, Ala.

The optical assembly was operated in a vacuum at both room temperature and cryogenic - or deep cold - temperatures to certify its performance before it is used to test the performance of Webb's 21.3 foot primary mirror. COCOA's operation and performance must be verified alone before it can be used to test Webb under conditions that the observatory will experience in space.

The Webb telescope includes 18 six-sided mirror segments, which work together to form one large, 21.3-foot mirror.

COCOA was built by ITT Exelis of Rochester, N.Y., and its subcontractor Micro Instruments in Rochester, N.Y.

The James Webb Space Telescope is the world's next-generation space observatory and successor to the Hubble Space Telescope.

The most powerful space telescope ever built, the Webb telescope will provide images of the first galaxies ever formed, and will explore planets around distant stars. It is a joint project of NASA, the European Space Agency and the Canadian Space Agency.