Digital Camera News

NASA Develops Microshutters for Webb Space Telescope

January 30, 2007 – NASA scientists announced this week that the James Webb Space Telescope is on it way, with its new microshutter array having recently passed crucial testing. The Webb Telescope is a follow-up to the Hubble Telescope, whose main camera malfunctioned today and shut down, according to BBC News. The Webb Telescope - with IR capabilities - contains over 62,000 microshutters to capture up to 100 objects in space and allow scientists to observe distant stars and galaxies, according to NASA representatives.

"The James Webb Telescope will look further back in time," said chief engineer of the Instrument Systems and Technology, Dr. Murzy Jhabvala of the Goddard Space Flight Center in an interview with DigitalCameraInfo.com.

With the microshutter array, this new telescope will be able to detect fainter objects in space that are more distant and possibly older.  The Webb Telescope may bring humans closer than ever before to the goal of reaching stars from when the universe orginally formed during the Big Bang.

After six years of development, the Webb Telescope stands apart from the Hubble and other previous telescopes with its unique microshutter array. Set to launch in the next decade, the Webb will go on a five year mission.

Jhabvala described the telescope shutter process as being like driving a car on a sunny day. The micro shutters act like sun visors, blocking out unwanted light to get a clear view of faint light, that is then optimally measured by a large-format detector.

The microshutter array is made of 62,415 tiny shutters, each measuring a tiny 100 x 200 microns or the width of a few hair strands. The entire microshutter array measures 1.5 inches and is close to the size of a postage stamp. During the mission, the thin shutter doors will open and close by applied voltage and magnets for approximately 50,000 times, according to Jhabvala.

When asked if controlling that many shutters would be difficult, Jhabvala noted that a camera has millions of pixel sensors, which makes controlling the shutters look like a much smaller task. Jhabvala said that the really difficult part will be controlling all the components together.

The microshutter array grid, with 171 rows x 365 columns of shutters, has a threshold of about 1 to 3 rows of broken shutters to yield a good result. The telescope also must operate at a frigid    -388°F (40 Kelvin), which is the temperature of the Near Infrared Spectrograph, according to a Jan. 24 NASA press release.

The microshutter array helps to detect up to one hundred objects in deep space and is a vital component of the Webb Telescope. Without the microshutters, the telescope could only detect one or two objects.

"It could enable science, revolutionize the way we look at the universe," said Jhabvala, "challenging the human imagination and future generations." Although the advantages of the Webb Telescope are hard to quantify, Jhabvala said, "the benefits that will emanate are extraordinary."

Interested readers can find more information about the James Webb Telescope at http://www.nasa.gov/home/hqnews/2007/jan/HQ_07014_Webb_microshutters.html.

Images courtesy of NASA