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The WIRE Instrument

The WIRE instrument is a cryogenically-cooled 30 cm Ritchey-Chretien telescope system that illuminates two 128x128 arsenic-doped silicon infrared detector arrays. A passive, two-stage solid hydrogen cryostat maintains the optics colder than 19 K and the detector arrays below 7.5 K. The optical system consists of the telescope primary and secondary mirrors, a dichroic beamsplitter, one optical passband filter, and baffles. The two channels of the instrument cover broad bands centered near 12 microns and 25 microns; the 25 micron band is the primary one for detecting starburst galaxies. The pixels are 15.5 arcseconds on a side, providing a 33x33 arcminute field of view in each passband. The instrument contains no moving parts. A cutaway is presented below.

  Cutaway of WIRE Instrument

The following table lists some important instrument and mission parameters:

Telescope 30 cm Ritchey Chretien
Detectors 128x128 Si:As BIB arrays
Passbands 21-27 microns, and 9-15 microns
Field of View 33x33 sq. arcminutes
Pixel Size 75 microns, or 15.5 arcsec
Final Spatial Resolution ~23 arcsec at 25 microns; ~20 arcsec at 12 microns 
Cryostat Dual-stage, solid hydrogen
Operating temperatures < 7.5 K (arrays), 12 K (optics)
Cryogen lifetime 4 months
Orbit 470x540 km, 97 deg inclination, Sun-synchronous orbit
Launch vehicle Air-launched Pegasus XL
Launch date >March 1, 1999

Please see the following for more information:

Telescope Photos Page.

Cryostat Photos Page.  


Last Updated: 9/3/97