The Webb Telescope's COCOA (IMAGE) NASA/Goddard Space Flight Center Caption The Center Of Curvature Optical Assembly (COCOA) will allow the program to verify the optical performance of the 21.3-foot (6.5-meter) primary mirror at its 40 degrees Kelvin (-233 Celsius) operating temperature. The COCOA contains mechanical and optical instruments that allow the test team to identify, align and test the 18-segments from outside the vacuum chamber. Credit Note: The background of this image has been digitally removed. Credit: ITT Exelis Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.