Webb's mirror, made of 18 individual segments, will be folded up inside the rocket that carries the telescope into orbit. Engineers are constructing the frame at the back of the mirror that will adjust Webb's segments to achieve a single perfect focus.
At Northrop Grumman, engineers are testing the systems that will control Webb from the ground. Because Webb will orbit 940,000 miles (1.5 million km) from Earth, it's vital to ensure perfect long-distance control.
Visitors to the World Science Festival in New York City were greeted by a startling sight: the Webb Space Telescope. The life-sized model of the telescope gave viewers a glimpse at the next big leap for orbiting observatories.
Webb is a reflecting telescope, which means it relies on mirrors to capture the light it uses to make images. At Tinsley Laboratories in California, Webb's multiple mirrors are taking shape and being tested.
The Webb Telescope's huge primary mirror is made up of 18 smaller mirrors. At NASA's Marshall Space Flight Center in Huntsville, Ala., environmental and thermal testing of these mirrors is preparing them for the hazards of space.
Because Webb sees infrared light, it must be kept extraordinarily cold. Perhaps the most important component for that task is Webb's huge sunshield, which protects the telescope from the Sun's energy.
Webb's "detectors" convert images into a digital signal that can be beamed to Earth. Join us at the Jet Propulsion Laboratory, Calif., where these vital pieces are undergoing testing.