NASA's Webb Telescope's Last Backbone Component Completed

          NASA's Webb Telescope's Last Backbone Component Completed

PR Newswire

WASHINGTON, June 14, 2013

WASHINGTON, June 14, 2013 /PRNewswire-USNewswire/ --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

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

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:

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

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


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