Scientists and engineers finish installing the primary mirrors on NASA's next-generation space observatory.
Once assembled, the James Webb Space Telescope will be the biggest and most powerful space telescope ever built. Its 18 primary mirror segments will work together as one large 21.3-foot diameter mirror to observe very distant objects in the cosmos. In February 2016, scientists and engineers completed installation of all of Webb’s primary mirrors onto the telescope in a large clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. The team used a robotic arm reminiscent of a claw machine to meticulously place each of the hexagonal-shaped mirror segments onto the telescope structure. Each mirror is made of ultra-lightweight beryllium and coated with a thin layer of gold. The light detected by the mirrors will provide astronomers with images of the first galaxies ever formed, helping them study the many phases in the history of our universe, including the evolution of our own solar system. Watch the video to see a time-lapse of the mirror installation.