Featured Research

from universities, journals, and other organizations

James Webb Space Telescope’s mirrors get 'shrouded'

Date:
June 7, 2012
Source:
NASA
Summary:
Earlier this year, NASA completed deep-freeze tests on the James Webb Space Telescope mirrors in a "shroud" at the X-ray & Cryogenic Facility (XRCF) at Marshall Space Flight Center in Huntsville, Ala.

In the photo, a batch of mirror segments sit on a stand that was placed inside a helium cooled shroud.
Credit: NASA

Earlier this year, NASA completed deep-freeze tests on the James Webb Space Telescope mirrors in a "shroud" at the X-ray & Cryogenic Facility (XRCF) at Marshall Space Flight Center in Huntsville, Ala.

All of the Webb's 18 main mirror segments were tested under conditions that they will experience when operating in space to verify they will work as expected. Tested in batches of six, the mirrors were transferred to the cryogenic testing chamber where they were plunged to a chilly -414 degrees Fahrenheit (-248 C). In the photo above, a batch of mirror segments sit on a stand that was placed inside a helium-cooled "shroud." The base of the shroud is visible in the lower left. The part that looks like a swing is a counterbalance weight for the crane that lifted the fully populated test stand into place.

"The large tube is the back of the helium shroud that will go around the mirrors and cool them," says Lee Feinberg, the NASA Optical Telescope Element Manager for the James Webb Space Telescope at the Goddard Space Flight Center in Greenbelt, Md., "The gaseous helium shroud sits inside of a liquid nitrogen shroud…which sits inside of a vacuum chamber. All three work together to create a vacuum and cold environment to test the mirrors."

That cold environment mimics the harsh cold of space. Once at sub-zero temperatures, the testing team measured the surface shape of the mirror segments to see how they performed at cryogenic temperatures. The team measured the mirror segments by using laser systems to illuminate them for reflection of the light back into a sensor. The sensor then measures the change in shape of the mirror as the temperature changes.

When fully deployed, the Webb's mirror will be over six times larger than that of the Hubble Space Telescope's mirror. It's designed to look farther away and further back in time, and will be able to detect light from distant galaxies.

But despite Webb's size, its segmented beryllium mirror technology is significantly lighter than Hubble's one-piece glass mirror technology. Each of the 18 hexagonal, gold-coated primary mirror segments is hollowed out and ribbed on the backside, which Feinberg explains "lightweights" them to reduce their mass while keeping their precise shape.

More information about the James Webb Space Telescope can be found at: http://www.jwst.nasa.gov/


Story Source:

The above story is based on materials provided by NASA. Note: Materials may be edited for content and length.


Cite This Page:

NASA. "James Webb Space Telescope’s mirrors get 'shrouded'." ScienceDaily. ScienceDaily, 7 June 2012. <www.sciencedaily.com/releases/2012/06/120607123555.htm>.
NASA. (2012, June 7). James Webb Space Telescope’s mirrors get 'shrouded'. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2012/06/120607123555.htm
NASA. "James Webb Space Telescope’s mirrors get 'shrouded'." ScienceDaily. www.sciencedaily.com/releases/2012/06/120607123555.htm (accessed July 24, 2014).

Share This




More Space & Time News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Cargo Craft Undocks from Space Station

Raw: Cargo Craft Undocks from Space Station

AP (July 22, 2014) A Russian Soyuz cargo-carrying spacecraft undocked from the International Space Station on Monday. The craft is due to undergo about ten days of engineering tests before it burns up in the Earth's atmosphere. (July 22) Video provided by AP
Powered by NewsLook.com
NASA Ceremony Honors Moon Walker Neil Armstrong

NASA Ceremony Honors Moon Walker Neil Armstrong

AP (July 21, 2014) NASA honored one of its most famous astronauts Monday by renaming a historic building at the Kennedy Space Center in Florida. It now bears the name of Neil Armstrong, the first man to walk on the moon. (July 21) Video provided by AP
Powered by NewsLook.com
Neil Armstrong's Post-Apollo 11 Life

Neil Armstrong's Post-Apollo 11 Life

Newsy (July 19, 2014) Neil Armstrong gained international fame after becoming the first man to walk on the moon in 1969. But what was his life like after the historic trip? Video provided by Newsy
Powered by NewsLook.com
This Week @ NASA, July 18, 2014

This Week @ NASA, July 18, 2014

NASA (July 18, 2014) Apollo 11 yesterday, Next Giant Leap tomorrow, Science instruments for Europa mission, and more... Video provided by NASA
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins