[meteorite-list] NASA's Webb Telescope's Last Backbone Component Completed

[Ron Baalke]

June 14, 2013

J.D. Harrington 
Headquarters, Washington 
202-358-5241 
j.d.harrington at nasa.gov 

Christina Thompson 
Northrop Grumman Corp., Redondo Beach, Calif. 
310-812-2375 
christina.thompson at ngc.com 

Jennifer Bowman 
ATK, Magna, Utah 
435-279-3159 
jennifer.bowman at atk.com 

RELEASE: 13-184

NASA'S WEBB TELESCOPE'S LAST BACKBONE COMPONENT COMPLETED

WASHINGTON -- Assembly of the backbone of NASA's James Webb Space 
Telescope, the primary mirror backplane support structure, is a step 
closer to completion with the recent addition of the backplane 
support frame, a fixture that will be used to connect all the pieces 
of the telescope together. 

The backplane support frame will bring together Webb's center section 
and wings, secondary mirror support structure, aft optics system and 
integrated science instrument module. ATK of Magna, Utah, finished 
fabrication under the direction of the observatory's builder, 
Northrop Grumman Corp. 

The backplane support frame also will keep the light path aligned 
inside the telescope during science observations. Measuring 11.5 feet 
by 9.1 feet by 23.6 feet and weighing 1,102 pounds, it is the final 
segment needed to complete the primary mirror backplane support 
structure. This structure will support the observatory's weight 
during its launch from Earth and hold its18-piece, 21-foot-diameter 
primary mirror nearly motionless while Webb peers into deep space. 

ATK has begun final integration of the backplane support frame to the 
backplane center section, which it completed in April 2012 and two 
backplane wing assemblies, which it completed in March. 

"Fabricating and assembling the backplane support frame of this size 
and stability is a significant technological step as it is one of the 
largest cryogenic composite structures ever built," said Lee 
Feinberg, James Webb Space Telescope optical telescope element 
manager at NASA's Goddard Space Flight Center in Greenbelt, Md. 

The frame, which was built at room temperature but must operate at 
temperatures ranging from minus 406 degrees to minus 343 degrees 
Fahrenheit, will undergo extremely cold, or cryogenic, thermal 
testing at NASA's Marshall Space Flight Center in Huntsville, Ala. 
The backplane support frame and primary mirror backplane support 
structure will shrink as they cool down in space. The tests, 
exceeding the low temperatures the telescope's backbone will 
experience in space, are to verify the components will be the right 
size and operate correctly in space. 

The primary mirror backplane support structure consists of more than 
10,000 parts, all designed, engineered and built by ATK. The support 
structure will measure about 24 feet tall, 19.5 feet wide and more 
than 11 feet deep when fully deployed, but weigh only 2,138 pounds 
with the wing assemblies, center section and backplane support frame 
attached. When the mission payload and instruments are installed, the 
fully populated support structure will support more than 7,300 
pounds, more than three times its own weight. 

The primary mirror backplane support structure also will meet 
unprecedented thermal stability requirements to minimize heat 
distortion. While the telescope is operating at a range of extremely 
cold temperatures, from minus 406 degrees to minus 343 degrees 
Fahrenheit, the backplane must not vary more than 38 nanometers 
(approximately 1 one-thousandth the diameter of a human hair). 

The primary backplane support structure is made of lightweight 
graphite materials using and advanced fabrication techniques. The 
composite parts are connected with precision metallic fittings made 
of invar and titanium. 

"The ATK team is providing program hardware that is arguably the 
largest and most advanced cryogenic structure ever built," said Bob 
Hellekson, ATK's Webb telescope program manager. 

The assembled primary backplane support structure and backplane 
support frame are scheduled for delivery to Marshall later this year 
for the extreme cryogenic thermal testing. They will undergo 
structural static testing at Northrop Grumman's facilities in Redondo 
Beach, Calif. in early 2014, and then be combined with the wing 
assemblies. 

The James Webb Space Telescope, the successor to NASA's Hubble Space 
Telescope, will be the most powerful space telescope ever built. It 
will observe the most distant objects in the universe, provide images 
of the first galaxies formed and see unexplored planets around 
distant stars. The Webb telescope is a joint project of NASA, the 
European Space Agency and the Canadian Space Agency. 

For more information about the completion of the center section of the 
backplane, visit: 

http://go.nasa.gov/Zuggpq 

For a "Behind the Webb" series video about the backplane, visit: 

http://go.nasa.gov/Zugltr 

For more information about the James Webb Space Telescope, visit: 

http://www.jwst.nasa.gov 
	
-end-