The microshutters are a new technology that was developed for the Webb telescope mission. The microshutter device is a key component Webb's Near Infrared Spectrograph (NIRSpec). NIRSpec is a powerful instrument that will record the spectra of light from distant objects. The microshutter device only lets light in from selected objects to shine through NIRSpec.
What is special about the microshutter device is it can select many objects in one viewing for simultaneous observation and it is programmable for any field of objects in the sky.
Other spectroscopic instruments have flown in space before but none have had this programmable multi-object capability that enables observation of up to 100 objects simultaneously, which means much more scientific investigating can get done in less time. Moreover, because NIRSpec's operating temperature is extremely cold or "cryogenic," the microshutter device posed a particularly difficult engineering challenge.
Microshutters are basically tiny windows with shutters that each measure 100 by 200 microns, or about the size of a bundle of only a few human hairs. They were conceptualized and created at NASA Goddard.
At right are two closeup views of the microshutters themselves.
The entire microshutter device consists of more than 62,000 individual windows with shutters arrayed in a waffle-like grid. One of four array quadrants of the microshutter device (shown at left) is about the size of a postage stamp. Four of these arrays are butted together two-by-two into one microshutter device.
Prior to an observation, each individual microshutter is opened or closed when a magnetic arm sweeps past, depending on whether or not it receives an electrical signal that tells it to be opened or closed. An open shutter lets light from a selected target in a particular part of the sky to pass through NIRSpec while a closed shutter blocks unwanted light from any objects that scientists don't want to observe. It is this programmable controllability that allows the instrument to do spectroscopy on so many different selected objects simultaneously from one viewing to the next
"To build a telescope that can peer farther than Hubble 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 over six years, opening and closing the tiny shutters tens of thousands of times in order to perfect the technology."
Harvey Moseley, the Microshutter Principal Investigator, adds, "The microshutters are a remarkable engineering feat that will have applications both in space and on the ground, even outside of astronomy in biotechnology, medicine and communications."
The microshutters are being provided by NASA/GFSC.
Read a news release about the microshutters (6/29/10):