Status of the x-ray flight mirror production for the ESA XMM spacecraft

The high throughput x-ray spectroscopy mission XMM is a 'Cornerstone' project in the ESA Horizon 2000 Programme for Space Science. This observatory has at its heart three highly nested Wolter 1 grazing incidence x-ray telescopes which will provide a large collecting area (1500 cm 2 each at 1.5 keV). This optical system has a spatial resolution of about 16 arcsec and when coupled with reflection grating spectrometers and x-ray CCD cameras, it will provide a major advance in astrophysics by the end of the century. In this paper, we first present the design of the telescope and then describe the manufacturing and the integration processes of the telescope, with the emphasis on the production of the x-ray mirrors. We then concentrate on the improvements made since the successful qualification of the XMM mirror module, last year. Last but not least, the results achieved with the first two flight models of the XMM telescope are also presented with some prospective on the next generation of ultra thin mirror shells.