XMMNewton

XMM-Newton, the X-ray Multi-Mirror Mission, is an European Space Agency space observatory designed for X-ray astronomy. Launched in 1999, it has conducted wide-ranging studies of astronomical phenomena such as black holes, neutron stars, supernova remnants, active galaxies, and clusters of galaxies, contributing extensively to high-energy astrophysics.

The mission employs three X-ray telescopes that use grazing-incidence mirrors to focus X-rays onto focal plane detectors. Each telescope houses a set of nested mirrors based on Wolter type I geometry, enabling large collecting areas and good angular resolution for X-ray observations. The spacecraft is designed to operate extended observing programs with high sensitivity across a broad energy band.

The payload consists of two main instrument suites. The European Photon Imaging Camera (EPIC) includes MOS1, MOS2, and PN detectors for imaging and moderate-resolution spectroscopy in the 0.15–15 keV range. The Reflection Grating Spectrometer (RGS) provides high-resolution spectroscopy in the soft X-ray band (about 0.35–2.5 keV). An Optical Monitor (OM) offers simultaneous optical and ultraviolet imaging and photometry, enabling multi-wavelength studies.

XMM-Newton follows a highly elliptical orbit with an apogee around 133,000 km and a perigee near 7,000 km, yielding long, uninterrupted observations of up to around two days. This orbit minimizes time lost to radiation belts and allows frequent, flexible scheduling. The mission was launched from Kourou aboard an Ariane 5 rocket and has seen multiple mission extensions, remaining operational for many years and producing a substantial portion of X-ray astronomy data and discoveries.