Jan. 24, 2007

Tabatha Thompson/Grey Hautaluoma
Headquarters, Washington 
202-358-3895/0668

Rob Gutro
Goddard Space Flight Center, Greenbelt, Md.
301-286-4044
RELEASE: 07-014

NASA CREATES MICROSCOPIC TECHNOLOGY FOR WEBB SPACE TELESCOPE

GREENBELT, Md. - NASA engineers and scientists building the James Webb 
Space Telescope have created a new telescope technology called 
"microshutters." Microshutters are tiny doorways the width of a few 
hairs that will allow the telescope to view the most distant stars 
and galaxies humans have ever seen.

The microshutters will enable scientists to mask unwanted light from 
foreground objects so the telescope can focus on the faint light of 
the first stars and galaxies that formed in the universe. Only the 
Webb Telescope has this technology. The Webb Telescope will launch in 
the next decade.

In December 2006, the microshutters passed crucial environmental 
testing to demonstrate that they can withstand the rigors of 
launching and placement in deep space. NASA's Goddard Space Flight 
Center, Greenbelt, Md., designed, tested and built the instrument 
technology. The microshutters will work in conjunction with the 
telescope's Near Infrared Spectrograph that is being built by the 
European Space Agency.

"To build a telescope that can peer farther than the Hubble Space 
Telescope can, we needed brand new technology," said Murzy Jhabvala, 
chief engineer of Goddard's Instrument Technology and Systems 
Division. "We've worked on this design for more than six years, 
opening and closing the tiny shutters tens of thousands of times to 
perfect the technology."

Each of the 62,000 shutters measures 100 by 200 microns, or roughly 
the width of three to six human hairs. The shutters are arranged in 
four identical grids that have a layout of 171 rows by 365 columns. 
These shutter grids are in front of an eight million-pixel infrared 
detector that records the light passing through the open shutters. 
The detector itself represents a technology breakthrough.

Astronomers using ground-based telescopes first take a picture of the 
sky and map all the objects in which they are interested. They then 
create a mask resembling a sieve to place on the telescope so that 
only the light from areas of interest can reach the telescope's 
detectors. 

In space, the Webb Telescope will have a wide field of view, and its 
deep, long observation of the sky will contain millions of light 
sources. Microshutters allow scientists to remotely and 
systematically block out light that they do not want, allowing the 
large-format detector to measure infrared spectra optimally. 
Previously, masks of space telescopes only covered large regions of a 
field of view at any one time. 

"The microshutters provide a conduit for faint light to reach the 
telescope detectors with very little loss," said Harvey Moseley, the 
Microshutter Principal Investigator at Goddard. "The shutters allow 
us to perform spectroscopy on up to 100 targets simultaneously. We 
will be able to see deeper in less time." 

Each shutter grid array is etched from a single piece of silicon, 
leaving a sculpture of cavities and doorframes with microscopic 
hinges and moving doors. The tiny shutters are laced with magnetic 
cobalt-iron strips. 

A passing magnet will open all the doors, pulling them down into the 
cavity. While the doors are opened, engineers can apply a combination 
of voltages to keep the selected microshutters open. The remainder 
close when the magnet moves away.

The microshutters must perform at a temperature of minus 388 degrees 
Fahrenheit (40 Kelvin, -233 degrees Celsius), which is the 
temperature of the Near Infrared Spectrograph. 

The microshutters are needed for observing distant, faint sources. 
Hubble's Ultra-Deep Field provides the deepest view of the universe, 
an image containing tens of thousands of light sources. Some of these 
light sources are relatively close and some are from an era just 
after galaxies and stars formed. To go deeper, scientists need to 
mask the brighter, closer sources and focus only on the most distant. 
The same microshutter technology also will efficiently reveal faint 
features in relatively nearby star fields, where scientists will 
analyze multiple sources at once.

"The microshutters are a remarkable engineering feat that will have 
applications both in space and on the ground, even outside the realm 
of astronomy in biotechnology, medicine and communications," said 
Moseley.

For diagrams and images of the microshutters, visit:



http://www.nasa.gov/vision/universe/starsgalaxies/microshutters.html

	
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