  X-ray Multi-Mirror Mission (XMM-Newton) has been one of the most successful
astronomy missions launched by the European Space Agency. It exploits
innovative use of replication technology for the X-ray reflecting telescopes
that has resulted in an unprecedented combination of effective area and
resolution. Three telescopes are equipped with imaging cameras and
spectrometers that operate simultaneously, together with a coaligned optical
telescope. The key features of the payload are described, and the in-orbit
performance and scientific achievements are summarised. Subject terms or
keywords: XMM-Newton, X-ray astronomy, space telescopes
