SPIRE beam steering mirror: a cryogenic 2 axis mechanism for the Herschel Space Observatory

The Beam Steering Mirror (BSM) subsystem is a critical part of the SPIRE Instrument for the ESA Herschel Space Observatory. It is used to steer the beam of the telescope on the photometer and spectrometer arrays in 2 orthogonal directions, for purposes of fully sampling the image, fine pointing and signal modulation. The UK Astronomy Technology Centre (ATC) is part of a consortium of 15 institutes in Europe and the USA which was formed to build SPIRE and which is lead by Dr M. Griffin of the University of Wales, Cardiff.