Performing tests on NASA's Webb Telescope in CIAF room

Performing tests on NASA's Webb Telescope in CIAF room

Technicians returning the James Webb Space Telescope ETU (engineering test unit) primary mirror segment to the cleanroom at at NASA's Goddard Space Flight Center in Greenbelt, Maryland on November 4, 2013 after undergoing some tests at the Calibration, Integration, and Alignment Facility (CIAF). The James Webb Space Telescope is the scientific successor to NASA's Hubble Space Telescope. It will be the most powerful space telescope ever built. Webb is an international project led by NASA with its partners, ESA (the European Space Agency) and the Canadian Space Agency. NASA Photo by Chris Gunn/UPI