Development of TES detectors for low-background far infrared space astronomy

The next generation of far infrared astronomy satellites will have cooled telescopes to reduce the thermal background to very low levels. In order to take advantage of the low background, arrays of sensitive detectors will be needed, with NEPs of 10^-19 W Hz^-1/2 or less -at least an order of magnitude better than can be achieved using conventional photoconductive detectors. We review the requirements for such arrays and report on the development of transition edge superconducting detectors suitable for use with an imaging spectrometer instrument in the 40-200 mum region.