The X-ray Multi Mirror (XMM-Newton) power system [spacecraft power]

The XMM-Newton X-ray observing astronomy mission, which is a prime component of ESA's scientific spacecraft programme for the new century, was launched by Ariane-504 from French Guiana on the 10th of December 1999. It was injected into a highly elliptical, 834 km/spl times/113990 km orbit, having an inclination with respect to the equator of 40/spl deg/. The spacecraft was built in Europe by an industrial team led by Dornier Space Systems (DSS) of Friedrichshafen, Germany with the onboard instruments provided by scientific institutions. The technical paper describes the XMM-Newton power system topology, its equipment characteristics and the early inflight operations. In addition two novel features related to the design of the electrical power system for XMM-Newton are reported in the technical paper, these being the implementation of a surface conductive network for the cover glasses of the solar cells and the extensive use of telecommandable and resettable latching current limiters (LCLs) for payload failure protection and ON/OFF switching.