DaimlerChrysler Aerospace
In June 1989, the mission's instruments had been selected and work began on spacecraft hardware. A project team was formed in January 1993 and based at the European Space Research and Technology Centre (ESTEC) in Noordwijk, Netherlands. Prime contractor Dornier Satellitensysteme (a subsidiary of the former DaimlerChrysler Aerospace) was chosen in October 1994 after the mission was approved into the implementation phase, with development and construction beginning in March 1996 and March 1997, respectively. The XMM Survey Science Centre was established at the University of Leicester in 1995. The three flight mirror modules for the X-ray telescopes were delivered by Italian subcontractor Media Lario in December 1998, and spacecraft integration and testing was completed in September 1999.