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New Technologies for James Webb Space Telescope Approved Early
05.02.07
 
More than a year ahead of schedule, a team of independent experts has approved all ten new technologies developed for NASA's James Webb Space Telescope. Many of the technologies are revolutionary and have never before been used on any satellite or space telescope. The early approval can reduce the risk of increased costs and schedule delays before the program is approved for further development.

Photo of one mirror segment of the JWST telescope Image right: This is one mirror segment. Each of the Webb telescope's 18 hexagonal shaped mirror segments is 1.3 meters (4.26 feet) in diameter, and weighs approximately 20 kilograms (46 pounds). The 18 mirror segments will form a single large mirror with a total area of 25 square-meters (almost 30 square yards) when they come together. + Click for high res image Credit: NASA

NASA commissioned the team of engineers, scientists and project managers to conduct the technical review. The group evaluated the telescope's near and mid-infrared detectors, sunshield materials, lightweight cryogenic mirrors, microshutter arrays, cryogenic detector readout application-specific integrated circuits, cryogenic heat switches, a large precision cryogenic structure, a cryocooler for the mid-infrared instrument, and wavefront sensing and control. They determined the technologies were tested successfully in a space-like environment and are mature enough to include on the telescope's upcoming mission.

The actual hardware and software that will fly on the telescope now can be engineered from working prototypes. These technologies will allow the observatory to peer back in time to about 400 million years after the Big Bang, enabling scientists to study the first generation of stars and galaxies.

Photo of the JWST testbed Image left : The Wavefront sensing and control system processes cosmic images through mathematical algorithms to calculate the mirror adjustments required to bring the image into focus. When the individual mirrors are properly aligned, the Webb telescope will be able to obtain extraordinarily sharp images and detect the faint glimmer of a distant galaxy. Ball Aerospace engineered a scaled telescope testbed, shown here, so that wavefront sensing and control can be developed and tested. + Click for high res image Credit: NASA

"The technology non-advocate review was our attempt to address one common problem that NASA missions encounter that leads to cost growth," said Eric Smith, Webb program scientist at NASA Headquarters, Washington. "That problem is late maturation of technology in a program's life-cycle. By conducting an external review of our technologies more than a year ahead of the Preliminary Design Review - when they are traditionally examined - we hope to better manage that aspect of the program's costs."

Two examples of the new technologies are the microshutter arrays and wavefront sensing and control.

Image of a JWST microshutter Image right: This is an array of microshutters, about the size of a postage stamp. Each shutter measures 100 by 200 microns, or about the width of three to six human hairs. These tiny shutters are arranged in a waffle-like grid containing over 62,000 shutters. The telescope will contain four of these waffle-looking grids. + Click for high res image Credit: NASA/Chris Gunn

Microshutters are tiny doorways, the width of a few hairs, that will allow scientists to remotely and systematically block out unwanted light and view the most distant stars and galaxies ever seen. The telescope will be the first project to employ this technology. Through a process called wavefront sensing and control, a set of algorithms and software programs, the optimum position of each of the telescope mirrors will be computed, and the positions will be adjusted as necessary, causing the individual mirrors to function as one very sensitive telescope.

"At the inception of the James Webb Space Telescope program, NASA adopted a strategy of making significant, early investments in the development of the diverse and challenging new technologies needed to conduct the mission," said Phil Sabelhaus, project manager at Goddard. "Receiving the review board's confirmation that we have met the goal more than a year early for all of our new technologies is a major accomplishment for our team and a tribute to the benefits of the early investment strategy," Sabelhaus said.

Close up of the JWST microshutter

Image above: Microshutters are tiny cells that measure 100 by 200 microns, or about the width of three to six human hairs. This is a closeup view of the microshutters. Credit: NASA

Northrop Grumman Corporation, Redondo Beach, Calif.; Ball Aerospace Corporation, Boulder, Colo.; Teledyne Imaging Systems, Thousand Oaks, Calif.; Utah State University's Space Dynamics Lab, North Logan, Utah; Raytheon Vision Systems, Santa Barbara, Calif.; Alliant Techsystems, Magna, Utah; and Sheldahl, Northfield, Minn., worked with NASA Goddard Space Flight Center, Greenbelt, Md., on these and other technologies.

The James Webb Space Telescope is expected to launch in 2013. The telescope is a joint project of NASA, the European Space Agency and the Canadian Space Agency.

Related Link:

+ JWST Project site

 
 
Rob Gutro
Goddard Space Flight Center