A giant robotic arm practiced hanging silver and gold mirrors on the backbone of the James Webb Space Telescope, then a human engineer carefully checked its work. Eventually, the full telescope will be launched into space, then unfold in a delicate choreography of inverse origami.
Top image: Optical Engineer Larkin Carey examines test mirrors in a giant cleanroom within Goddard Space Flight Center in Greenbelt, Maryland. Credit: NASA/Chris Gunn
Central portion of the telescope backplane, tilted on its side. Image credit: NASA/Chris Gunn
Pathfinder is the giant black composite spine of the optical telescope, supporting the primary mirror segments. This is a non-flight prototype, allowing everyone to practice in advance of the real deal of assembling the flight structure next summer.
The telescope is going to be a cross between a monster machine and intricate origami, launching as a compact parcel that will blossom and unfold once it reaches orbit far above the Earth. This is the first time a space telescope will use a light, segmented primary mirror, but if it goes well, it will dramatically expand possibilities for other future space telescopes. The successor to the wildly-popular Hubble Space Telescope, James Webb Space Telescope will be the largest optical telescope yet, capable of seeing even farther into the past of our universe.
The James Webb Space Telescope is scheduled to launch in 2018, when it will start searching the most likely planets for signs of alien life. Other portions of the telescope are undergoing testing and manufacturing in cleanrooms scattered around the country.