Mirror polishing completed for James Webb Space Telescope

Posted by John McHaleREDONDO BEACH, Calif., 2 July 2011. Northrop Grumman engineers completed mirror polishing on NASA Goddard Space Flight Center's James Webb Space Telescope enabling the observatory to see objects as far away as the first galaxies in the universe. The prime contractor for the telescope is Northrop Grumman Corp. (NYSE:NOC).The Webb telescope has four different types of mirrors. The primary one has an area of approximately 25 square meters, which will enable experts to capture light from distant objects in the universe faster than any previous space observatory. The mirrors are made of beryllium and will work in concert to relay images of deep space to the telescope's science cameras."This milestone is the culmination of a decade-long process," says Scott Willoughby, vice president and Webb Telescope program manager for Northrop Grumman Aerospace Systems. "We had to invent an entire new mirror technology to give Webb the ability to see back in time."The mirrors were polished at L3 Integrated Optical Systems -- Tinsley located in Richmond, Calif., to accuracies of less than one millionth of an inch. Such precision is important for forming the sharpest images when the mirrors cool to -400 degrees Fahrenheit in the cold of space.Once polished, the mirrors get coated with a microscopically thin layer of gold to enable efficient reflection of infrared light. NASA experts completed coating 13 of 18 primary mirror segments and will complete the rest by early 2012. The 18 segments fit together to make one large mirror 21.3 feet across.The James Webb Space Telescope is the successor to the Hubble Space Telescope and will be the most powerful space telescope in history once built. It now has more than 75 percent of its hardware either completed, in production, or undergoing testing. The telescope is a joint project of NASA, the European Space Agency, and the Canadian Space Agency.