Herschel-SPIRE: Design, Performance, and Scientific Capabilities Matthew Griffin *,a , Alain Abergel b , Peter Ade a , Philippe André c , Jean-Paul Baluteau d , James Bock e , Alberto Franceschini f , Walter Gear a , Jason Glenn g , Douglas Griffin h , Ken King h , Emmanuel Lellouch i , David Naylor j , Göran Olofsson k , Ismael Perez-Fournon l , Michael Rowan-Robinson m , Paolo Saraceno n , Eric Sawyer i , Alan Smith o , Bruce Swinyard i , Laurent Vigroux p , and Gillian Wright q a School of Physics and Astronomy, Cardiff University, 5 The Parade, Cardiff CF24 3YB, UK; b Institut d’Astrophysique Spatiale, Orsay, France; c Service d’Astrophysique, CEA, Saclay, France ; d Observatoire de Marseille, France ; e Jet Propulsion Laboratory, Pasadena, California, USA; f Università di Padova, Italy; g University of Colorado, Boulder, Colorado, USA; h Rutherford Appleton Laboratory, Oxfordshire, UK; i Observatoire de Paris, France; j University of Lethbridge, Lethbridge, Alberta, Canada; k Stockholm Observatory, Sweden; l Instituto de Astrofísica de Canarias, Tenerife, Spain; m Imperial College, University of London, UK; n Istituto di Fisica dello Spazio Interplanetario, Rome, Italy; o Mullard Space Science Laboratory, Surrey, UK; p Institut d’Astrophysique de Paris, France; q UK Astronomy Technology Centre, Edinburgh, UK. ABSTRACT SPIRE, the Spectral and Photometric Imaging Receiver, is a submillimetre camera and spectrometer for the European Space Agency’s Herschel Space Observatory. It comprises a three-band imaging photometer operating at 250, 360 and 520 μm, and an imaging Fourier Transform Spectrometer (FTS) covering 200-670 μm. The detectors are arrays of feedhorn-coupled NTD spider-web bolometers cooled to 0.3 K . The photometer field of view of is 4 x 8 arcmin., observed simultaneously in the three spectral bands. The FTS has an approximately circular field of view with a diameter of 2.6 arcmin., and employs a dual-beam configuration with broad-band intensity beam dividers to provide high efficiency and separated output and input ports. The spectral resolution can be adjusted between 0.04 and 2 cm -1 (resolving power of 20-1000 at 250 μm). The flight instrument is currently undergoing integration and test. The design of SPIRE is described, and the expected scientific performance is summarised, based on modelling and flight instrument test results. Keywords: Herschel, Far Infrared, Submillimetre, Instrumentation * E-mail: matt.griffin@astro.cf.ac.uk; Telephone: +44-(0)29-2087-4203; Fax: +44-(0)29-2087-4056