MIRI on JWST - challenges in science, technology and partnership

MIRI, the Mid Infrared Instrument, is one of the four scientific instruments on-board the James Webb Space Telescope JWST. MIRI combines spectroscopic and imaging capabilities, including coronagraphy, between 5 and 28 microns with unprecedented sensitivity and spatial and spectral resolution. The required cooling of the detector arrays to around 6 K which is provided by a MIRI-dedicated multi-stage mechanical cooler. The complements of the JWST science payload at near-infrared wavelengths between 0.4 and 5 microns are a camera (NIRCam), a spectrometer (NIRSpec) and a Fine Guidance Sensor. Being set up as a partnership between centers in Europe and the US, MIRIs different components are being developed, integrated and tested at these various centers prior to final integration and test in Europe and delivery via the European Space Agency to the JWST project at NASA´s Goddard Space Flight Center. JWST will be launched in 2014 on an Ariane 5 from the European Space Port in Kourou, French Guiana, to the 2nd Lagrange point L2 of the Sun-Earth system. This paper describes the design and development of MIRI within the JWST observatory and discusses the particular challenges of the set-up as a consortium and a partnership.