The SPectral and Imaging REceiver is one of a suite of three instruments on board the Herschel Space Observatory, which is intended for launch in 2007.  Herschel and SPIRE will be used to observe the cool interstellar medium and sites of star formation in the Milky Way, as well as high star formation-rate galaxies out to high redshifts (z>1). 

SPIRE has two compononents:  A 3-color, 337-pixel mapping photometer and a two-band imaging Fourier Transform Spectrometer for 200 - 670 um.  The 300 mK bolometers are composed of silicon nitride micromesh absorbers and germanium thermistors, with a similar design as Bolocam's bolometers. The radiation from the telescope is coupled to the bolometers by a close-packed array of precision-machined feedhorns.  The photometer will be used to map thermal emission from dust in molecular clouds in the Milky Way and nearby galaxies.  The observations will enable the dust temperature to be measured and the mass of interstellar gas to be estimated.  SPIRE will also be used to detect thousands of submillimeter galaxies, high-redshift (z>1) galaxies with extreme luminosities (>10¹³ solar luminosities) and star formation rates (~10³ solar masses per year).  The spectrometer will be used to map molecular and atomic line emission in the Milky Way to probe the temperature, density, and kinematics of the gas in the interstellar medium.

SPIRE is a consortium of many institutions, headed by the University of Cardiff.  The bolometer arrays are being fabricated at JPL.

Some useful SPIRE links:
http://herschel.jpl.nasa.gov/

http://www.rssd.esa.int/SA-general/Projects/Herschel/

	This photograph shows the partially assembled SPIRE cold qualification model at the Rutherford Appleton Lab.  The backs of three mirrors are visible (lower left) as are the casings of the three photometric bolometer array assemblies (cylinders in the upper right; courtesy RAL).
	A collection of neutron transmutation doped germanium thermistors before being indium bump bonded to the absorber array.  The dime shows the size scale!
	A zoom-in on a single silicon nitride micromesh ("spider web") bolometer.  The spider web mesh absorbs submillimeter radiation and germanium thermistor in the center detects the radiation (courtesy JPL).
	A photograph of a SPIRE bolometer array with a pen for scale (courtesy Dr. Jamie Bock at JPL).  The bolometers are biased and read out via the gold leads on the silicon wafer
	The bolometer detector array assembly for the middle band, 350 um.  The inner part of the assembly will operate at a temperature of 300 milliKelvin.  It is mechanically suspended and thermally isolated from the 2 Kelvin outer structure by Kevlar string.  The entrance apertures of the feedhorns that feed radiation to the bolometers from the telescope are visible at the top center  (courtesy Jamie Bock).