The X-ray Multi-Mirror Mission XMM, the second cornerstone of the science programme Horizon 2000 of ESA, is used, after launch from Kourou, French Guiana on 10 December 1999 with an ARIANE V, to perform X-ray astronomical studies of selected cosmic sources in a highly eccentric (7000 km × 114000 km) 48-hours orbit over a time span of ten years.

The scientific payload includes three parallel Wolter type I telescopes, in the focus of each an X-ray CCD will take spectrally resolved images in the energy band between 0.3 keV and 10 keV.

In addition to the MPE participation in the development of the telecopes, the X-ray tests (Telescope Scientist) and the development and construction of the pn-CCD camera (EPIC-pn) the MPE has taken up further tasks in the framework of the Europian Survey Scientist Consortium (SSC).

The main job is the execution of the standard analysis of every XMM observation and the identification of the X-ray sources discovered. The XMM spacecraft has been designed and is being built by the company Dornier Satellitensysteme as main contractor leading an industrial consortium.