[7] Initially funded for two years, with a ten-year design life, the spacecraft remains in good health and has received repeated mission extensions, most recently in March 2023 and is scheduled to operate until the end of 2026.

[9] The observational scope of XMM-Newton includes the detection of X-ray emissions from astronomical objects, detailed studies of star-forming regions, investigation of the formation and evolution of galaxy clusters, the environment of supermassive black holes and mapping of the mysterious dark matter.

[11][12] The XMM mission was formally proposed to the ESA Science Programme Committee in 1984 and gained approval from the Agency's Council of Ministers in January 1985.

[11][15] A project team was formed in January 1993 and based at the European Space Research and Technology Centre (ESTEC) in Noordwijk, Netherlands.

[11][16] The three flight mirror modules for the X-ray telescopes were delivered by Italian subcontractor Media Lario in December 1998,[14] and spacecraft integration and testing was completed in September 1999.

[2] Forty minutes after being released from the Ariane upper stage, telemetry confirmed to ground stations that the spacecraft's solar arrays had successfully deployed.

Engineers waited an additional 22 hours before commanding the on-board propulsion systems to fire a total of five times, which, between 10 and 16 December, changed the orbit to 7,365 × 113,774 km (4,576 × 70,696 mi) with a 38.9-degree inclination.

He noted that because Newton is synonymous with gravity and one of the goals of the satellite was to locate large numbers of black hole candidates, "there was no better choice than XMM-Newton for the name of this mission.

While some concern was expressed that the vehicle may have suffered a catastrophic event, photographs taken by amateur astronomers at the Starkenburg Observatory in Germany and at other locations worldwide showed that the spacecraft was intact and appeared on course.

A weak signal was finally detected using a 35-metre (115 ft) antenna in New Norcia, Western Australia, and communication with XMM-Newton suggested that the spacecraft's Radio Frequency switch had failed.

After troubleshooting a solution, ground controllers used NASA's 34 m (112 ft) antenna at the Goldstone Deep Space Communications Complex to send a command that changed the switch to its last working position.

[26][27][28] Because of the spacecraft's good health and the significant returns of data, XMM-Newton has received several mission extensions by ESA's Science Programme Committee.

As part of the approval, it was noted that the satellite had enough on-board consumables (fuel, power and mechanical health) to theoretically continue operations past 2017.

[11][24] The instruments on board XMM-Newton are three European Photon Imaging Cameras (EPIC), two Reflection Grating Spectrometers (RGS), and an Optical Monitor.

Surrounding this component is the Service Module, which carries various spacecraft support systems: computer and electric busses, consumables (such as fuel and coolant), solar arrays, the Telescope Sun Shield, and two S-band antennas.

Behind these units is the Telescope Tube, a 6.8-metre (22 ft) long, hollow carbon fibre structure which provides exact spacing between the mirrors and their detection equipment.

They were developed and built by the University of Leicester Space Research Centre and EEV Ltd.[25][38][40] The pn-CCD camera is used to detect high-energy X-rays, and is composed of a single silicon chip with twelve individual embedded CCDs.

The RGS system operates in the 2.5 to 0.35 keV (5 to 35 ångström) range, which allows detection of carbon, nitrogen, oxygen, neon, magnesium, silicon and iron.

[44][45] The Focal Plane Cameras each consist of nine MOS-CCD devices mounted in a row and following a curve called a Rowland circle.

The camera systems were a joint effort between SRON, the Paul Scherrer Institute, and MSSL, with EEV Ltd and Contraves Space providing hardware.

Each 10 × 20 cm (4 × 8 in) grating is composed of 1 mm (0.039 in) thick silicon carbide substrate covered with a 2,000-ångström (7.9×10−6 in) gold film, and is supported by five beryllium stiffeners.

[44][45] The Optical Monitor (OM) is a 30 cm (12 in) Ritchey–Chrétien optical/ultraviolet telescope designed to provide simultaneous observations alongside the spacecraft's X-ray instruments.

The Optical Monitor was built by the Mullard Space Science Laboratory with contributions from organisations in the United States and Belgium.

[48][49] Feeding the EPIC and RGS systems are three telescopes designed specifically to direct X-rays into the spacecraft's primary instruments.

The finished mirrors were glued into the grooves of an Inconel spider, which keeps them aligned to within the five-micron tolerance required to achieve adequate X-ray resolution.

The mandrels were manufactured by Carl Zeiss AG, and the electroforming and final assembly were performed by Media Lario with contributions from Kayser-Threde.

[2][54][55] Coarse spacecraft orientation and orbit maintenance is provided by two sets of four 20-newton (4.5 lbf) hydrazine thrusters (primary and backup).

[64] The object SCP 06F6, discovered by the Hubble Space Telescope (HST) in February 2006, was observed by XMM-Newton in early August 2006 and appeared to show an X-ray glow around it[65] two orders of magnitude more luminous than that of supernovae.

[66] In June 2011, a team from the University of Geneva, Switzerland, reported XMM-Newton seeing a flare that lasted four hours at a peak intensity of 10,000 times the normal rate, from an observation of Supergiant Fast X-ray Transient IGR J18410-0535, where a blue supergiant star shed a plume of matter that was partly ingested by a smaller companion neutron star with accompanying X-ray emissions.

[69][70] In February 2014, separate analyses extracted from the spectrum of X-ray emissions observed by XMM-Newton a monochromatic signal around 3.5 keV.