View source for XMM-Newton

{{short description|X-ray space observatory}}
{{Infobox spaceflight |auto=all
| name                  = ''XMM-Newton''
| names_list            = High Throughput X-ray Spectroscopy Mission <br /> X-ray Multi-Mirror Mission

| image                 = XMM-Newton spacecraft model.png
| image_caption         = Artist's impression of the ''XMM-Newton'' spacecraft
| image_size            = 300px

| mission_type          = [[X-ray astronomy]]
| operator              = [[European Space Agency]]
| COSPAR_ID             = 1999-066A
| SATCAT                = 25989
| website               = http://sci.esa.int/xmm-newton/ <br /> http://xmm.esac.esa.int/
| mission_duration      = Planned: 10 years<ref>{{cite web |url=https://www.esa.int/Our_Activities/Space_Science/XMM-Newton_factsheet |title=XMM-Newton factsheet |publisher=European Space Agency |date=20 August 2014 |access-date=16 June 2018}}</ref> <br /> Elapsed: {{time interval|10 December 1999 14:32|show=ymd|sep=,}}

| manufacturer          = Dornier Satellitensysteme, [[Carl Zeiss AG|Carl Zeiss]], Media Lario, [[Matra Marconi Space]], BPD Difesa e Spazio, [[Fokker Space]]<ref name="Wilson2005">{{cite book |chapter-url=http://www.esa.int/esapub/br/br250/br250.pdf |chapter=XMM-Newton |title=ESA Achievements |edition=3rd |publisher=European Space Agency |first=Andrew |last=Wilson |pages=206–209 |date=June 2005 |id=ESA Publication BR-250 |isbn=92-9092-493-4}}</ref>
| launch_mass           = {{convert|3764|kg|lb|abbr=on}}<ref name="Wilson2005"/>
| dry_mass              = {{convert|3234|kg|lb|abbr=on}}
| dimensions            = Length: {{convert|10.8|m|ft|0|abbr=on}}<ref name="Wilson2005"/> <br /> Span: {{convert|16.16|m|ft|0|abbr=on}}<ref name="Wilson2005"/>
| power                 = 1,600 watts<ref name="Wilson2005"/>

| launch_date           = {{start-date|10 December 1999, 14:32}}&nbsp;UTC<ref name="esa19991210">{{cite news |url=http://sci.esa.int/xmm-newton/38447-10-december-launch/ |title=A Faultless Launch |publisher=European Space Agency |date=10 December 1999 |access-date=21 September 2014}}</ref>
| launch_rocket         = [[Ariane 5]]G No. 504<ref name="gunter-ariane">{{cite web |url=http://space.skyrocket.de/doc_lau/ariane-5.htm |title=Ariane-5 |work=Gunter's Space Page |access-date=21 September 2014}}</ref>
| launch_site           = [[Guiana Space Centre]] [[ELA-3]]<ref name="Wilson2005"/><ref name="gunter-ariane"/>
| launch_contractor     = [[Arianespace]]
| entered_service       = 1 July 2000<ref name="Wilson2005"/>

| disposal_type         = <!--Whether the spacecraft was deorbited, decommissioned, placed in a graveyard orbit, etc-->
| deactivated           = presumed end of 2026 or later<ref name="esa-20230307"/>
| destroyed             = <!--when craft was destroyed (if other than by re-entry)-->
| last_contact          = 
| decay_date            = <!--when craft re-entered the atmosphere, not needed if it landed-->

| orbit_reference       = [[Geocentric orbit|Geocentric]]
| orbit_semimajor       = {{convert|65648.3|km|mi|abbr=on}}
| orbit_eccentricity    = 0.816585
| orbit_periapsis       = {{convert|5662.7|km|mi|abbr=on}}
| orbit_apoapsis        = {{convert|112877.6|km|mi|abbr=on}}
| orbit_inclination     = 67.1338&nbsp;degrees
| orbit_period          = 2789.9&nbsp;minutes
| orbit_epoch           = 4 February 2016, 01:06:30&nbsp;UTC<ref name="heavens-above">{{cite web |url=http://heavens-above.com/orbit.aspx?satid=25989 |title=XMM – Orbit |work=Heavens Above |date=3 February 2016 |access-date=3 February 2016}}</ref>
| apsis                 = gee

| telescope_type        = 3 × [[Wolter telescope|Wolter type-1]]<ref name="Wilson2005"/>
| telescope_diameter    = Outer mirror: {{convert|70|cm|in|0|abbr=on}}<ref name="Wilson2005"/> <br /> Inner mirror: {{convert|30.6|cm|in|0|abbr=on}}<ref name="Wilson2005"/>
| telescope_focal_length= {{convert|7.5|m|ft|0|abbr=on}}<ref name="Wilson2005"/>
| telescope_area        = {{convert|0.1475|m2|0|abbr=on}} at 1.5 [[keV]]<ref name="Wilson2005"/> <br /> {{convert|0.0580|m2|0|abbr=on}} at 8 keV<ref name="Wilson2005"/>
| telescope_wavelength  = 0.1–12&nbsp;[[electronvolt|keV]] (12–0.1&nbsp;[[nanometre|nm]])<ref name="Wilson2005"/>
| telescope_resolution  = 5 to 14 arcseconds<ref name="Wilson2005"/>
| instruments_list      = {{Infobox spaceflight/Instruments
   | acronym1 = EPIC | name1 = European Photon Imaging Camera
   | acronym2 = RGS  | name2 = Reflection Grating Spectrometer
   | acronym3 = OM   | name3 = Optical Monitor
 }}

| insignia              = File:XMM-Newton insignia.png
| insignia_caption      = ESA astrophysics insignia for ''XMM-Newton''
| insignia_alt          = XMM-Newton mission insignia
| insignia_size         = 180x180px

| programme             = '''[[European Space Agency Science Programme#Horizon 2000|Horizon 2000]]'''
| previous_mission      = ''[[Huygens (spacecraft)|Huygens]]''
| next_mission          = [[Cluster II (spacecraft)|Cluster II]]
}}
[[File:Animation of XMM-Newton trajectory.gif|280px|thumb|right|Animation of XMM-Newton{{'s}} trajectory around Earth]]
'''''XMM-Newton''''', also known as the '''High Throughput X-ray Spectroscopy Mission''' and the '''X-ray Multi-Mirror Mission''', is an [[X-ray]] [[space observatory]] launched by the [[European Space Agency]] in December 1999 on an [[Ariane 5]] rocket. It is the second cornerstone mission of ESA's [[Horizon 2000]] programme. Named after physicist and astronomer Sir [[Isaac Newton]], the spacecraft is tasked with investigating interstellar X-ray sources, performing narrow- and broad-range [[spectroscopy]], and performing the first simultaneous imaging of objects in both X-ray and optical ([[visible spectrum|visible]] and [[ultraviolet]]) wavelengths.<ref name="xmm-objectives">{{cite web |url=http://sci.esa.int/xmm-newton/31355-objectives/ |title=XMM-Newton: Objectives |publisher=European Space Agency |date=8 July 2011 |access-date=5 February 2016}}</ref>

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.<ref name="esa-20230307">{{cite web |url=https://sci.esa.int/web/director-desk/-/extended-life-for-esa-s-science-missions |title=Extended life for ESA's science missions |work=[[ESA]] |date=7 March 2023 |access-date=20 March 2023}}</ref> ESA plans to succeed ''XMM-Newton'' with the [[Advanced Telescope for High Energy Astrophysics]] (ATHENA), the second large mission in the [[Cosmic Vision]] 2015–2025 plan, to be launched in 2035.<ref>{{cite web |url=https://sci.esa.int/web/athena/-/59896-mission-summary |title=Athena Mission Summary |publisher=European Space Agency |date=2 May 2022 |access-date=28 November 2022}}</ref> ''XMM-Newton'' is similar to [[NASA]]'s [[Chandra X-ray Observatory]], also launched in 1999.

As of May 2018, close to 5,600 [[academic paper|papers]] have been published about either ''XMM-Newton'' or the scientific results it has returned.<ref name="xmm-papers">{{cite conference |url=https://www.cosmos.esa.int/documents/332006/1713846/mission_status.pdf |title=XMM-Newton Overall Mission Status |conference=XMM-Newton Users' Group Meeting #19. 17–18 May 2018. Villafranca del Castillo, Spain. |first=Peter |last=Kretschmar |date=2018}}</ref>

== Concept and mission history ==
The observational scope of ''XMM-Newton'' includes the [[X-ray astronomy|detection of X-ray]] emissions from astronomical objects, detailed studies of star-forming regions, investigation of the formation and evolution of [[galaxy cluster]]s, the environment of [[supermassive black hole]]s and mapping of the mysterious [[dark matter]].<ref name="bulletin141">{{cite journal |url=http://esamultimedia.esa.int/multimedia/publications/ESA-Bulletin-141/pageflip.html |title=10 years of discovery: Commemorating XMM-Newton's first decade |journal=ESA Bulletin |first1=Norbert |last1=Schartel |first2=María |last2=Santos-Lleo |first3=Arvind |last3=Parmar |first4=Jean |last4=Clavel |issue=141 |pages=2–9 |date=February 2010 |issn=0376-4265}}</ref>

In 1982, even before the launch of ''XMM-Newton''{{'s}} predecessor ''[[EXOSAT]]'' in 1983, a proposal was generated for a "multi-mirror" X-ray telescope mission.<ref name="xmm-overview">{{cite web |url=http://www.esa.int/Our_Activities/Space_Science/XMM-Newton_overview |title=XMM-Newton overview |publisher=European Space Agency |date=4 June 2013 |access-date=31 January 2016}}</ref><ref name="Jansen2001">{{cite journal |url=http://www.aanda.org/articles/aa/pdf/2001/01/aaxmm39.pdf |title=XMM-Newton observatory. I. The spacecraft and operations |journal=[[Astronomy and Astrophysics]] |first1=F. |last1=Jansen |first2=D. |last2=Lumb |first3=B. |last3=Altieri |first4=J. |last4=Clavel |first5=M. |last5=Ehle |first6=C. |last6=Erd |first7=C. |last7=Gabriel |first8=M. |last8=Guainazzi |first9=P. |last9=Gondoin |first10=R. |last10=Much |first11=R. |last11=Munoz |first12=M. |last12=Santos |first13=N. |last13=Schartel |first14=D. |last14=Texier |first15=G. |last15=Vacanti |display-authors=5 |volume=365 |issue=1 |pages=L1–L6 |date=2001 |doi=10.1051/0004-6361:20000036 |bibcode=2001A&A...365L...1J|doi-access=free }}</ref> 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.<ref name="aeat2000">{{cite journal |title=Universe X-rayed and British science honoured |journal=Aircraft Engineering and Aerospace Technology |publisher=Emerald Group |volume=72 |issue=4 |year=2000 |doi=10.1108/aeat.2000.12772daf.010}}</ref> That same year, several [[working group]]s were established to determine the feasibility of such a mission,<ref name="xmm-overview"/> and mission objectives were presented at a [[academic conference|workshop]] in Denmark in June 1985.<ref name="Jansen2001"/><ref name="Lumb2012">{{cite journal |title=X-ray Multi-mirror Mission (XMM-Newton) observatory |journal=Optical Engineering |first1=David H. |last1=Lumb |first2=Norbert |last2=Schartel |first3=Fred A. |last3=Jansen |volume=51 |issue=1 |at=011009 |date=February 2012 |doi=10.1117/1.OE.51.1.011009 |bibcode=2012OptEn..51a1009L |arxiv=1202.1651|s2cid=119237088 }}</ref> At this workshop, it was proposed that the spacecraft contain 12 low-energy and 7 high-energy X-ray telescopes.<ref name="Lumb2012"/><ref name="Palombara2010">{{cite web |url=http://www.iasf-milano.inaf.it/Astro-Siesta/astro_nicola_2_XMM.pdf |title=Twenty years with XMM (and even more...) |publisher=[[INAF|Istituto Nazionale di Astrofisica]] |first=Nicola |last=La Palombara |date=12 September 2010 |access-date=31 January 2016}}</ref> The spacecraft's overall configuration was developed by February 1987, and drew heavily from lessons learned during the ''EXOSAT'' mission;<ref name="xmm-overview"/> the Telescope Working Group had reduced the number of X-ray telescopes to seven standardised units.<ref name="Lumb2012"/><ref name="Palombara2010"/> In June 1988 the European Space Agency approved the mission and issued a call for investigation proposals (an "announcement of opportunity").<ref name="xmm-overview"/><ref name="Palombara2010"/> Improvements in technology further reduced the number of X-ray telescopes needed to just three.<ref name="Palombara2010"/>

In June 1989, the mission's instruments had been selected and work began on spacecraft hardware.<ref name="xmm-overview"/><ref name="Palombara2010"/> A project team was formed in January 1993 and based at the [[European Space Research and Technology Centre]] (ESTEC) in [[Noordwijk]], Netherlands.<ref name="aeat2000"/> 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.<ref name="aeat2000"/><ref name="Lumb2012"/> The XMM Survey Science Centre was established at [[School of Physics and Astronomy, University of Leicester|School of Physics and Astronomy]] at the [[University of Leicester]] in 1995.<ref name="xmm-overview"/><ref name="SSC-Leicester">{{cite web |url=http://xmmssc-www.star.le.ac.uk/ |title=XMM-Newton Survey Science Centre |publisher=[[University of Leicester]] |access-date=31 January 2016 |archive-date=15 February 2016 |archive-url=https://web.archive.org/web/20160215073013/http://xmmssc-www.star.le.ac.uk/ |url-status=dead }}</ref> The three flight mirror modules for the X-ray telescopes were delivered by Italian subcontractor Media Lario in December 1998,<ref name="Lumb2012"/> and spacecraft integration and testing was completed in September 1999.<ref name="aeat2000"/>

''XMM'' left the ESTEC integration facility on 9 September 1999, taken by road to [[Katwijk]] then by the barge ''Emeli'' to [[Rotterdam]]. On 12 September, the spacecraft left Rotterdam for [[French Guiana]] aboard [[Arianespace]]{{'s}} transport ship MN ''Toucan''.<ref name="esa19990913">{{cite news |url=http://sci.esa.int/xmm-newton/13050-black-beauty-sails-to-the-tropics/ |title='Black Beauty' sails to the tropics |publisher=European Space Agency |date=13 September 1999 |access-date=3 February 2016}}</ref> The ''Toucan'' docked at the French Guianese town of [[Kourou]] on 23 September, and was transported to [[Guiana Space Centre]]{{'s}} Ariane 5 Final Assembly Building for final launch preparation.<ref name="esa19990927">{{cite news |url=http://sci.esa.int/xmm-newton/13062-xmm-arrives-in-french-guiana/ |title=XMM arrives in French Guiana |publisher=European Space Agency |date=27 September 1999 |access-date=3 February 2016}}</ref>

Launch of ''XMM'' took place on 10 December 1999 at 14:32&nbsp;UTC from the Guiana Space Centre.<ref name="nssdc-orbit">{{cite web |url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1999-066A |title=XMM-Newton: Trajectory Details |work=National Space Science Data Center |publisher=NASA |access-date=1 February 2016 |archive-date=4 March 2016 |archive-url=https://web.archive.org/web/20160304123329/http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=1999-066A |url-status=dead }}</ref> ''XMM'' was lofted into space aboard an [[Ariane 5]] rocket, and placed into a highly elliptical, 40-degree orbit that had a [[apsis|perigee]] of {{convert|838|km|mi|abbr=on}} and an [[apsis|apogee]] of {{convert|112473|km|mi|abbr=on}}.<ref name="Wilson2005"/> 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 {{convert|7365|xx|113774|km|mi|abbr=on}} with a 38.9-degree inclination. This resulted in the spacecraft making one complete [[orbit|revolution]] of the Earth approximately every 48 hours.<ref name="Wilson2005"/><ref name="xmm-orbit-nav">{{cite web |url=http://sci.esa.int/xmm-newton/31349-orbit-navigation/ |title=XMM-Newton: Orbit/Navigation |publisher=European Space Agency |date=19 September 2011 |access-date=2 February 2016}}</ref>

Immediately after launch, ''XMM'' began its [[Launch and Early Orbit phase]] of operations.<ref name="xmm-operations">{{cite web |url=http://www.esa.int/Our_Activities/Operations/XMM-Newton_operations |title=XMM-Newton Operations |publisher=European Space Agency |access-date=3 February 2016}}</ref> On 17 and 18 December 1999, the X-ray modules and Optical Monitor doors were opened, respectively.<ref name="esa-1999-54">{{cite press release |url=http://sci.esa.int/xmm-newton/13167-pr-54-1999-xmm-flying-beautifully/ |title=PR 54-1999: XMM flying beautifully |publisher=European Space Agency |date=20 December 1999 |access-date=3 February 2016 |id=PR 54-1999}}</ref> Instrument activation started on 4 January 2000,<ref name="Wilson2005"/> and the Instrument Commissioning phase began on 16 January.<ref name="heasarc-new">{{cite web |url=http://heasarc.gsfc.nasa.gov/docs/xmm/xmmhp_whatsnew.html |title=XMM-Newton What's New |publisher=NASA |access-date=3 February 2016 |archive-date=6 February 2016 |archive-url=https://web.archive.org/web/20160206184553/http://heasarc.gsfc.nasa.gov/docs/xmm/xmmhp_whatsnew.html |url-status=dead }}</ref> The Optical Monitor (OM) attained first light on 5 January, the two European Photon Imaging Camera (EPIC) [[Metal Oxide Semiconductor|MOS]]-[[charge-coupled device|CCDs]] followed on 16 January and the EPIC [[p–n junction|pn]]-CCD on 22 January, and the Reflection Grating Spectrometers (RGS) saw first light on 2 February.<ref name="heasarc-new"/> On 3 March, the Calibration and Performance Validation phase began,<ref name="Wilson2005"/> and routine science operations began on 1 June.<ref name="heasarc-new"/>

During a press conference on 9 February 2000, ESA presented the first images taken by ''XMM'' and announced that a new name had been chosen for the spacecraft. Whereas the program had formally been known as the High Throughput X-ray Spectroscopy Mission, the new name would reflect the nature of the program and the originator of the field of spectroscopy. Explaining the new name of ''XMM-Newton'', Roger Bonnet, ESA's former Director of Science, said, "We have chosen this name because Sir Isaac Newton was the man who invented spectroscopy and XMM is a spectroscopy mission." 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."<ref name="xmm-fact-sheet">{{cite web |url=http://sci.esa.int/xmm-newton/31250-fact-sheet/ |title=XMM-Newton: Fact Sheet |publisher=European Space Agency |date=21 December 2012 |access-date=3 February 2016}}</ref>

Including all construction, spacecraft launch, and two years of operation, the project was accomplished within a budget of {{€|689 million|link=yes}} (1999 conditions).<ref name="aeat2000"/><ref name="Lumb2012"/>

===Operation===
{{anchor|Cooling}}The spacecraft has the ability to lower the operating temperature of both the EPIC and RGS cameras, a function that was included to counteract the deleterious effects of ionising [[radiation]] on the camera [[pixel]]s. In general, the instruments are cooled to reduce the amount of [[dark current (physics)|dark current]] within the devices. During the night of 3–4 November 2002, RGS-2 was cooled from its initial temperature of {{convert|-80|C|F|0}} down to {{convert|-113|C|F|0}}, and a few hours later to {{convert|-115|C|F|0}}. After analysing the results, it was determined the optimal temperature for both RGS units would be {{convert|-110|C|F|0}}, and during 13–14 November, both RGS-1 and RGS-2 were set to this level. During 6–7 November, the EPIC MOS-CCD detectors were cooled from their initial operating temperature of {{convert|-100|C|F|0}} to a new setting of {{convert|-120|C|F|0}}. After these adjustments, both the EPIC and RGS cameras showed dramatic improvements in quality.<ref name="xmm-cam-cooling">{{cite web |url=http://xmm.esac.esa.int/external/xmm_news/items/cooling02/index.shtml |title=First results from XMM-Newton RGS and EPIC MOS instruments cooling |publisher=European Space Agency |date=11 November 2002 |access-date=5 February 2016 |archive-date=6 February 2016 |archive-url=https://web.archive.org/web/20160206195039/http://xmm.esac.esa.int/external/xmm_news/items/cooling02/index.shtml |url-status=dead }}</ref>

On 18 October 2008, ''XMM-Newton'' suffered an unexpected communications failure, during which time there was no contact with the spacecraft. 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 {{convert|35|m|ft|adj=on}} 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 {{convert|34|m|ft|adj=on|abbr=on}} antenna at the [[Goldstone Deep Space Communications Complex]] to send a command that changed the switch to its last working position. ESA stated in a press release that on 22 October, a ground station at the [[European Space Astronomy Centre]] (ESAC) made contact with the satellite, confirming the process had worked and that the satellite was back under control.<ref name="aero20081023">{{cite news |url=http://www.aero-news.net/index.cfm?do=main.textpost&id=11b62d59-623b-49f2-b8c1-f815b24f9738 |title=ESA Receives An Orbital Call For Help |work=Aero-News.net |date=23 October 2008 |access-date=5 February 2016}}</ref><ref name="esa20081022">{{cite web |url=http://sci.esa.int/xmm-newton/43591-re-establishing-contact-with-xmm-newton/ |title=Re-establishing contact with XMM-Newton |publisher=European Space Agency |date=22 October 2008 |access-date=5 February 2016}}</ref><ref name="esa20081023">{{cite web |url=http://www.esa.int/Our_Activities/Space_Science/XMM-Newton_talks_again_loud_and_clear |title=XMM-Newton talks again loud and clear |publisher=European Space Agency |date=23 October 2008 |access-date=5 February 2016}}</ref>

===Mission extensions===
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. The first extension came during November 2003 and extended operations through March 2008.<ref name="xmm-extend-2003">{{cite web |url=http://xmm.esac.esa.int/external/xmm_news/news_list/xmm_news-2003-12-01.shtml |title=XMM-Newton-NEWS #36 |publisher=European Space Agency |date=1 December 2003 |access-date=4 February 2016 |archive-date=6 February 2016 |archive-url=https://web.archive.org/web/20160206201351/http://xmm.esac.esa.int/external/xmm_news/news_list/xmm_news-2003-12-01.shtml |url-status=dead }}</ref> The second extension was approved in December 2005, extending work through March 2010.<ref name="xmm-extend-2005">{{cite web |url=http://sci.esa.int/xmm-newton/38397-mission-extension-approved/ |title=XMM-Newton Mission Extension Approved |publisher=European Space Agency |date=6 December 2005 |access-date=4 February 2016}}</ref> A third extension was passed in November 2007, which provided for operations through 2012. 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.<ref name="xmm-extend-2007">{{cite web |url=http://sci.esa.int/xmm-newton/41772-xmm-newton-mission-extension-approved/ |title=XMM-Newton Mission Extension Approved |publisher=European Space Agency |date=15 November 2007 |access-date=4 February 2016}}</ref> The fourth extension in November 2010 approved operations through 2014.<ref name="esa20101122">{{cite web |url=http://www.esa.int/Our_Activities/Space_Science/Europe_maintains_its_presence_on_the_final_frontier |title=Europe maintains its presence on the final frontier |publisher=European Space Agency |date=22 November 2010 |access-date=5 February 2016}}</ref> A fifth extension was approved in November 2014 and affirmed in November 2016, continuing operations through 2018.<ref name="esa20141120">{{cite web |url=http://sci.esa.int/director-desk/54999-working-life-extensions-for-esas-science-missions/ |title=Working life extensions for ESA's science missions |publisher=European Space Agency |date=20 November 2014 |access-date=5 February 2016}}</ref><ref>{{Cite web|title=ESA Science & Technology - Two-year extensions confirmed for ESA's science missions|url=https://sci.esa.int/web/director-desk/-/58589-two-year-extensions-confirmed-for-esa-s-science-missions|access-date=2021-07-09|website=sci.esa.int}}</ref> A sixth extension was approved in December 2017, continuing operations through the end of 2020.<ref>{{Cite web|title=ESA Science & Technology – Green light for continued operations of ESA science missions|url=https://sci.esa.int/web/director-desk/-/59839-green-light-for-continued-operations-of-esa-science-missions|access-date=2021-07-09|website=sci.esa.int}}</ref> A seventh extension was approved in November 2018, continuing operations through the end of 2022.<ref>{{Cite web|title=ESA Science & Technology - Extended life for ESA's science missions|url=https://sci.esa.int/web/director-desk/-/60943-extended-life-for-esas-science-missions|access-date=2021-07-09|website=sci.esa.int}}</ref> An eighth extension was approved in March 2023, continuing operations through the end of 2026, with indicative extension up to 2029.<ref name="esa-20230307" />

== Spacecraft ==
[[File:XMM-Newton.jpg|thumb|Mock-up of ''XMM-Newton'' at the ''[[Cité de l'espace]]'', [[Toulouse]]]]
''XMM-Newton'' is a {{convert|10.8|m|ft|0|adj=on}} long space telescope, and is {{convert|16.16|m|ft|0|abbr=on}} wide with solar arrays deployed. At launch it weighed {{convert|3764|kg|lb}}.<ref name="Wilson2005"/> The spacecraft has three degrees of stabilisation, which allow it to aim at a target with an accuracy of 0.25 to 1 [[minute of arc|arcseconds]]. This stabilisation is achieved through the use of the spacecraft's [[#AOCS|Attitude & Orbit Control Subsystem]]. These systems also allow the spacecraft to point at different celestial targets, and can turn the craft at a maximum of 90 degrees per hour.<ref name="xmm-overview" /><ref name="xmm-fact-sheet" /> The instruments on board ''XMM-Newton'' are three European Photon Imaging Cameras (EPIC), two Reflection Grating [[Spectrometer]]s (RGS), and an Optical Monitor.

The spacecraft is roughly cylindrical in shape, and has four major components. At the fore of the spacecraft is the ''Mirror Support Platform'', which supports the X-ray telescope assemblies and grating systems, the Optical Monitor, and two [[star tracker]]s. Surrounding this component is the ''Service Module'', which carries various spacecraft support systems: [[Bus (computing)|computer]] and [[electric bus]]ses, consumables (such as fuel and [[coolant]]), [[photovoltaic system|solar arrays]], the Telescope Sun Shield, and two [[S band|S-band]] antennas. Behind these units is the ''Telescope Tube'', a {{convert|6.8|m|ft|adj=on}} long, hollow [[carbon fibre]] structure which provides exact spacing between the mirrors and their detection equipment. This section also hosts [[outgassing]] equipment on its exterior, which helps remove any contaminants from the interior of the satellite. At the aft end of spacecraft is the ''Focal Plane Assembly'', which supports the Focal Plane Platform (carrying the cameras and spectrometers) and the data-handling, power distribution, and radiator assemblies.<ref name="bulletin100">{{cite journal |url=http://esamultimedia.esa.int/multimedia/publications/ESA-Bulletin-100/ |title=An Overview of the XMM Observatory System |journal=Bulletin |publisher=European Space Agency |first1=H. |last1=Barré |first2=H. |last2=Nye |first3=G. |last3=Janin |issue=100 |pages=15–20 |date=December 1999 |volume=100 |bibcode=1999ESABu.100...15B |issn=0376-4265}}</ref>

== Instruments ==

=== European Photon Imaging Cameras{{anchor|EPIC}} ===
The three ''European Photon Imaging Cameras'' (EPIC) are the primary instruments aboard ''XMM-Newton''. The system is composed of two [[Metal Oxide Semiconductor|MOS]]–[[Charge-coupled device|CCD]] cameras and a single [[p–n junction|pn]]-CCD camera, with a total field of view of 30 [[minute of arc|arcminutes]] and an energy sensitivity range between {{nowrap|0.15 and 15 [[electronvolt|keV]]}} ({{nowrap|82.7 to 0.83 [[ångström]]s}}). Each camera contains a six-position [[optical filter|filter wheel]], with three types of X-ray-transparent filters, a fully open and a fully closed position; each also contains a radioactive source used for internal calibration. The cameras can be independently operated in a variety of modes, depending on the image sensitivity and speed needed, as well as the intensity of the target.<ref name="xmm-instruments-epic">{{cite web |url=http://sci.esa.int/xmm-newton/31281-instruments/?fbodylongid=774 |title=XMM-Newton: Instruments: European Photon Imaging Camera (EPIC) |publisher=European Space Agency |date=18 August 2015 |access-date=6 February 2016}}</ref><ref name="xmm-manual-332">{{cite web |url=http://xmm.esac.esa.int/external/xmm_user_support/documentation/uhb/epicmode.html |title=Science modes of the EPIC cameras |work=XMM-Newton Users' Handbook |publisher=European Space Agency |page=3.3.2 |id=Issue 2.13 |date=20 July 2015 |access-date=6 February 2016 |archive-date=15 December 2015 |archive-url=https://web.archive.org/web/20151215120029/http://xmm.esac.esa.int/external/xmm_user_support/documentation/uhb/epicmode.html |url-status=dead }}</ref><ref name="Turner2001">{{cite journal |url=http://www.aanda.org/articles/aa/pdf/2001/01/aaxmm47.pdf |title=The European Photon Imaging Camera on XMM-Newton: The MOS cameras |journal=[[Astronomy and Astrophysics]] |first1=M. J. L. |last1=Turner |first2=A. |last2=Abbey |first3=M. |last3=Arnaud |first4=M. |last4=Balasini |first5=M. |last5=Barbera |display-authors=etal |volume=365 |issue=1 |pages=L27–L35 |date=January 2001 |doi=10.1051/0004-6361:20000087 |bibcode=2001A&A...365L..27T |arxiv=astro-ph/0011498|s2cid=17323951 }}</ref>

The two MOS-CCD cameras are used to detect low-energy X-rays. Each camera is composed of seven [[silicon chip]]s (one in the centre and six circling it), with each chip containing a matrix of 600 × 600 [[pixel]]s, giving the camera a total resolution of about 2.5 [[megapixel]]s. As [[#Cooling|discussed above]], each camera has a large adjacent [[radiator]] which cools the instrument to an operating temperature of {{convert|-120|C|F|0}}. They were developed and built by the [[University of Leicester]] Space Research Centre and [[English Electric Valve Company|EEV Ltd]].<ref name="xmm-cam-cooling" /><ref name="xmm-instruments-epic" /><ref name="Turner2001" />

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. Each CCD is 64 × 189 pixels, for a total capacity of 145,000 pixels. At the time of its construction, the pn-CCD camera on ''XMM-Newton'' was the largest such device ever made, with a sensitive area of {{convert|36|cm2|abbr=on}}. A radiator cools the camera to {{convert|-90|C|F|0}}. This system was made by the [[University of Tübingen|Astronomisches Institut Tübingen]], the [[Max Planck Institute for Extraterrestrial Physics]], and PNSensor, all of Germany.<ref name="xmm-instruments-epic" /><ref name="pnsensor">{{cite web |url=http://www.pnsensor.de/Welcome/Detectors/pn-CCD/index.php |title=Detector Concept of pn-CCDs |website=PNSensor.de |date=2 July 2008 |access-date=6 February 2016}}</ref><ref name="Struder2001">{{cite journal |url=http://www.aanda.org/articles/aa/pdf/2001/01/aaxmm35.pdf |title=The European Photon Imaging Camera on XMM-Newton: The pn-CCD camera |journal=[[Astronomy and Astrophysics]] |first1=L. |last1=Strüder |first2=U. |last2=Briel |first3=K. |last3=Dennerl |first4=R. |last4=Hartmann |first5=E. |last5=Kendziorra |display-authors=etal |volume=365 |issue=1 |pages=L18–L26 |date=January 2001 |doi=10.1051/0004-6361:20000066 |bibcode=2001A&A...365L..18S|doi-access=free }}</ref>

The EPIC system records three types of data about every X-ray that is detected by its CCD cameras. The time that the X-ray arrives allows scientists to develop [[light curve]]s, which projects the number of X-rays that arrive over time and shows changes in the brightness of the target. Where the X-ray hits the camera allows for a visible image to be developed of the target. The amount of energy carried by the X-ray can also be detected and helps scientists to determine the physical processes occurring at the target, such as its temperature, its chemical make-up, and what the environment is like between the target and the telescope.<ref name="leicaster-epic">{{cite web |url=http://www.src.le.ac.uk/projects/xmm/instrument/ |title=The EPIC-MOS instruments on-board XMM-Newton |work=University of Leicester |first=Darren |last=Baskill |date=14 September 2006 |archive-url=https://web.archive.org/web/20070701101611/http://www.src.le.ac.uk/projects/xmm/instrument/ |archive-date=1 July 2007}}</ref>

=== Reflection Grating Spectrometers{{anchor|RGS}} ===
The ''Reflection Grating Spectrometers'' (RGS) are composed of two Focal Plane Cameras and their associated Reflection Grating Arrays. This system is used to build [[X-ray spectroscopy|X-ray spectral data]] and can determine the [[chemical element|elements]] present in the target, as well as the temperature, quantity and other characteristics of those elements. The RGS system operates in the {{nowrap|2.5 to 0.35 keV}} ({{nowrap|5 to 35 ångström}}) range, which allows detection of carbon, nitrogen, oxygen, neon, magnesium, silicon and iron.<ref name="denHerder2001">{{cite journal |url=http://www.aanda.org/articles/aa/pdf/2001/01/aaxmm19.pdf |title=The Reflection Grating Spectrometer on board XMM-Newton |journal=[[Astronomy and Astrophysics]] |first1=J. W. |last1=den Herder |first2=A. C. |last2=Brinkman |first3=S. M. |last3=Kahn |first4=G. |last4=Branduardi-Raymont |first5=K. |last5=Thomsen |display-authors=etal |volume=365 |issue=1 |pages=L7–L17 |date=January 2001 |doi=10.1051/0004-6361:20000058 |bibcode=2001A&A...365L...7D|doi-access=free }} den Herder (2001) states that the RGS system operates in the {{nowrap|6 to 38 ångström}} range, but the majority of sources, including official ESA websites, contradict this.</ref><ref name="Brinkman1998">{{cite conference |url=http://xmm.esac.esa.int/external/xmm_science/workshops/1st_workshop/procs/brinkmanb.pdf |title=The Reflection Grating Spectrometer on board XMM |conference=Science with XMM. 30 September-2 October 1998. Noordwijk, The Netherlands. |first1=A. |last1=Brinkman |first2=H. |last2=Aarts |first3=A. |last3=den Boggende |first4=T. |last4=Bootsma |first5=L. |last5=Dubbeldam |display-authors=etal |year=1998 |bibcode=1998sxmm.confE...2B |access-date=13 February 2016 |archive-date=15 December 2015 |archive-url=https://web.archive.org/web/20151215162502/http://xmm.esac.esa.int/external/xmm_science/workshops/1st_workshop/procs/brinkmanb.pdf |url-status=dead }}</ref>

The Focal Plane Cameras each consist of nine MOS-CCD devices mounted in a row and following a curve called a [[Rowland circle]]. Each CCD contains 384 × 1024 pixels, for a total resolution of more than 3.5 megapixels. The total width and length of the CCD array was dictated by the size of the RGS spectrum and the wavelength range, respectively. Each CCD array is surrounded by a relatively massive wall, providing heat conduction and [[radiation]] shielding. Two-stage radiators cool the cameras to an operating temperature of {{convert|-110|C|F|0}}. The camera systems were a joint effort between [[Netherlands Institute for Space Research|SRON]], the [[Paul Scherrer Institute]], and [[Mullard Space Science Laboratory|MSSL]], with EEV Ltd and Contraves Space providing hardware.<ref name="xmm-cam-cooling" /><ref name="denHerder2001" /><ref name="Brinkman1998" /><ref name="xmm-support-tech-rgs">{{cite web |url=http://xmm.esac.esa.int/external/xmm_user_support/documentation/technical/RGS/index.shtml |title=The Reflection Grating Spectrometer (RGS) onboard XMM-Newton |publisher=European Space Agency |access-date=6 February 2016 |archive-date=29 December 2015 |archive-url=https://web.archive.org/web/20151229025038/http://xmm.esac.esa.int/external/xmm_user_support/documentation/technical/RGS/index.shtml |url-status=dead }}</ref><ref name="xmm-instruments-rgs">{{cite web |url=http://sci.esa.int/xmm-newton/31281-instruments/?fbodylongid=797 |title=XMM-Newton: Instruments: Reflection Grating Spectrometer (RGS) |publisher=European Space Agency |date=18 August 2015 |access-date=6 February 2016}}</ref>

The Reflection Grating Arrays are attached to two of the primary telescopes. They allow approximately 50% of the incoming X-rays to pass unperturbed to the EPIC system, while redirecting the other 50% onto the Focal Plane Cameras. Each RGA was designed to contain 182 identical gratings, though a fabrication error left one with only 181. Because the telescope mirrors have already focused the X-rays to converge at the focal point, each grating has the same angle of incidence, and as with the Focal Plane Cameras, each grating array conforms to a Rowland circle. This configuration minimises focal aberrations. Each {{convert|10|xx|20|cm|in|0|abbr=on}} grating is composed of {{convert|1|mm|abbr=on}} thick [[silicon carbide]] substrate covered with a {{convert|2000|Å|adj=on|lk=in}} [[gold]] film, and is supported by five [[beryllium]] stiffeners. The gratings contain a large number of grooves, which actually perform the X-ray deflection; each grating contains an average of 646 grooves per millimetre. The RGAs were built by [[Columbia University]].<ref name="denHerder2001" /><ref name="Brinkman1998" />

=== Optical Monitor{{anchor|OM}} ===
The ''Optical Monitor'' (OM) is a {{convert|30|cm|in|0|abbr=on}} [[Ritchey–Chrétien telescope|Ritchey–Chrétien]] optical/ultraviolet telescope designed to provide simultaneous observations alongside the spacecraft's X-ray instruments. The OM is sensitive between {{nowrap|170 and 650}} nanometres in a 17 × 17 arcminute square field of view co-aligned with the centre of the X-ray telescope's field of view. It has a [[focal length]] of {{convert|3.8|m|ft|0|abbr=on}} and a [[focal ratio]] of ƒ/12.7.<ref name="xmm-instruments-om">{{cite web |url=http://sci.esa.int/xmm-newton/31281-instruments/?fbodylongid=798 |title=XMM-Newton: Instruments: Optical Monitor (OM) |publisher=European Space Agency |date=18 August 2015 |access-date=6 February 2016}}</ref><ref name="Mason2001">{{cite journal |url=http://www.aanda.org/articles/aa/pdf/2001/01/aaxmm33.pdf |title=The XMM-Newton optical/UV monitor telescope |journal=[[Astronomy and Astrophysics]] |first1=K. O. |last1=Mason |first2=A. |last2=Breeveld |first3=R. |last3=Much |first4=M. |last4=Carter |first5=F. A. |last5=Cordova |display-authors=etal |volume=365 |issue=1 |pages=L36–L44 |date=January 2001 |doi=10.1051/0004-6361:20000044 |bibcode=2001A&A...365L..36M |arxiv=astro-ph/0011216|s2cid=53630714 }}</ref>

The instrument is composed of the Telescope Module, containing the optics, detectors, processing equipment, and power supply; and the Digital Electronics Module, containing the instrument control unit and data processing units. Incoming light is directed into one of two fully redundant detector systems. The light passes through an 11-position [[optical filter|filter wheel]] (one opaque to block light, six broad band filters, one white light filter, one magnifier, and two [[grism]]s), then through an intensifier which amplifies the light by one million times, then onto the CCD sensor. The CCD is 384 × 288 pixels in size, of which 256 × 256 pixels are used for observations; each pixel is further subsampled into 8 × 8 pixels, resulting in a final product that is 2048 × 2048 in size. The Optical Monitor was built by the [[Mullard Space Science Laboratory]] with contributions from organisations in the United States and Belgium.<ref name="xmm-instruments-om"/><ref name="Mason2001"/>

== Telescopes ==
[[File:xray_telescope_lens.svg|thumb|250px|Focusing X-rays with glancing reflection in a Wolter Type-1 optical system]]
Feeding the EPIC and RGS systems are three telescopes designed specifically to direct X-rays into the spacecraft's primary instruments. The telescope assemblies each have a diameter of {{convert|90|cm|in|0|abbr=on}}, are {{convert|250|cm|in|0|abbr=on}} in length, and have a base weight of {{convert|425|kg|lb|abbr=on}}. The two telescopes with Reflection Grating Arrays weigh an additional {{convert|20|kg|lb|abbr=on}}. Components of the telescopes include (from front to rear) the mirror assembly door, entrance and X-ray [[wikt:baffle|baffles]], mirror module, electron deflector, a Reflection Grating Array in two of the assemblies, and exit baffle.<ref name="aeat2000" /><ref name="xmm-mirror-intro">{{cite web |url=http://sci.esa.int/xmm-newton/31318-x-ray-mirrors/ |title=XMM-Newton: X-ray Mirrors: Introduction |publisher=European Space Agency |date=3 April 2013 |access-date=5 February 2016}}</ref><ref name="xmm-mirror-config">{{cite web |url=http://sci.esa.int/xmm-newton/31318-x-ray-mirrors/?fbodylongid=800 |title=XMM-Newton: X-ray Mirrors: Configuration |publisher=European Space Agency |date=3 April 2013 |access-date=5 February 2016}}</ref><ref name="xmm-mirror-design">{{cite web |url=http://sci.esa.int/xmm-newton/31318-x-ray-mirrors/?fbodylongid=801 |title=XMM-Newton: X-ray Mirrors: Optical Design |publisher=European Space Agency |date=3 April 2013 |access-date=5 February 2016}}</ref>

Each telescope consists of 58 cylindrical, nested [[Wolter telescope|Wolter Type-1 mirrors]] developed by Media Lario of Italy, each {{convert|600|mm|in|abbr=on}} long and ranging in diameter from {{convert|306|to|700|mm|in|abbr=on}}, producing a total collecting area of {{convert|4425|cm2|0|abbr=on}} at 1.5 [[Electronvolt|keV]] and {{convert|1740|cm2|0|abbr=on}} at 8 keV.<ref name="Wilson2005"/> The mirrors range from {{convert|0.47|mm|in|2|abbr=on}} thick for the innermost mirror to {{convert|1.07|mm|in|2|abbr=on}} thick for the outermost mirror, and the separation between each mirror ranges from {{convert|1.5|to|4|mm|in|2|abbr=on}} from innermost to outermost.<ref name="Wilson2005"/> Each mirror was built by vapour-depositing a 250&nbsp;nm layer of gold reflecting surface onto a highly polished aluminium [[mandrel]], followed by [[electroforming]] a monolithic [[nickel]] support layer onto the gold. 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]].<ref name="bulletin089">{{cite journal |url=http://esamultimedia.esa.int/multimedia/publications/ESA-Bulletin-089/ |title=Producing the X-Ray Mirrors for ESA's XMM spacecraft |journal=Bulletin |publisher=European Space Agency |first1=D. |last1=de Chambure |first2=R. |last2=Lainé |first3=K. |last3=van Katwijk |first4=J. |last4=van Casteren |first5=P. |last5=Glaude |issue=89 |pages=68–79 |date=February 1997 |issn=0376-4265}}</ref>

== Subsystems ==

=== Attitude & Orbit Control System{{anchor|AOCS}} ===
Spacecraft three-axis [[Spacecraft attitude control|attitude control]] is handled by the ''Attitude & Orbit Control System'' (AOCS), composed of four [[reaction wheel]]s, four [[inertial measurement unit]]s, two [[star tracker]]s, three fine [[Sun sensor]]s, and three Sun acquisition sensors. The AOCS was provided by [[Matra Marconi Space]] of the United Kingdom.<ref name="Wilson2005"/><ref name="xmm-engineering-aocs">{{cite web |url=http://sci.esa.int/xmm-newton/31314-engineering/?fbodylongid=802 |title=XMM-Newton: Engineering: Attitude and Orbital Control Systems (AOCS) |publisher=European Space Agency |date=19 September 2011 |access-date=7 February 2016}}</ref><ref name="xmm-manual-362">{{cite web |url=http://xmm.esac.esa.int/external/xmm_user_support/documentation/uhb/aocs.html |title=Attitude & Orbit Control Subsystem (AOCS) |work=XMM-Newton Users' Handbook |publisher=European Space Agency |page=3.6.2 |id=Issue 2.13 |date=20 July 2015 |access-date=6 February 2016 |archive-date=15 December 2015 |archive-url=https://web.archive.org/web/20151215120819/http://xmm.esac.esa.int/external/xmm_user_support/documentation/uhb/aocs.html |url-status=dead }}</ref>

Coarse spacecraft orientation and orbit maintenance is provided by two sets of four {{convert|20|N|adj=on|lk=on}} [[hydrazine]] thrusters (primary and backup).<ref name="Wilson2005"/> The hydrazine thrusters were built by [[DASA|DASA-RI]] of Germany.<ref name="esa19991217">{{cite web |url=http://sci.esa.int/xmm-newton/13180-jets-in-space-xmm-unique-pictures/ |title=Jets in space: XMM unique pictures |publisher=European Space Agency |date=17 December 1999 |access-date=12 February 2016}}</ref>

The AOCS was upgraded in 2013 with a software patch ('4WD'), to control attitude using the 3 prime reaction wheels plus the 4th, spare wheel, unused since launch, with the aim of saving propellant to extend the spacecraft lifetime.<ref>{{Cite web|last=Speed|first=Richard|title=The ultimate 4-wheel-drive: How ESA's keeping XMM-Newton alive after 20 years and beyond|url=https://www.theregister.com/2020/05/01/xmm-newton/|access-date=2020-12-31|website=www.theregister.com|language=en}}</ref><ref>{{cite web |last1=Pantaleoni |first1=Mauro |title=XMM-Newton's operational challenge of changing the attitude control to 4 active reaction wheels, after 12 years of routine operations |url=https://www.researchgate.net/publication/229462136 |website=ResearchGate |access-date=31 December 2020}}</ref> In 2019 the fuel was predicted to last until 2030.<ref>{{cite web |last1=Kirsch |first1=Marcus |title=XMM-Newton -MOC preparing for the 3rd decade of operations |url=https://www.cosmos.esa.int/documents/332006/3791206/02_10_Kirsch.pdf |publisher=ESA |access-date=31 December 2020}}</ref>

=== Power systems ===
Primary power for ''XMM-Newton'' is provided by two fixed solar arrays. The arrays are composed of six panels measuring {{convert|1.81|xx|1.94|m|ft|abbr=on}} for a total of {{convert|21|m2|sqft|abbr=on}} and a mass of {{convert|80|kg|lb|abbr=on}}. At launch, the arrays provided 2,200 W of power, and were expected to provide 1,600 W after ten years of operation. Deployment of each array took four minutes. The arrays were provided by [[Fokker Space]] of the Netherlands.<ref name="Wilson2005"/><ref name="esa19990818">{{cite web |url=http://sci.esa.int/xmm-newton/13035-xmm-spreads-its-wings-for-the-last-time-on-earth/ |title=XMM spreads its wings for the last time on Earth |publisher=European Space Agency |date=18 August 1999 |access-date=12 February 2016}}</ref>

When direct sunlight is unavailable, power is provided by two [[nickel–cadmium battery|nickel–cadmium batteries]] providing 24 [[A·h]] and weighing {{convert|41|kg|lb|abbr=on}} each. The batteries were provided by [[Saft Groupe S.A.|SAFT]] of France.<ref name="Wilson2005"/><ref name="esa19990818"/>

=== Radiation Monitor System{{anchor|ERMS}} ===
The cameras are accompanied by the ''EPIC Radiation Monitor System'' (ERMS), which measures the radiation environment surrounding the spacecraft; specifically, the ambient proton and electron flux. This provides warning of damaging radiation events to allow for automatic shut-down of the sensitive camera CCDs and associated electronics. The ERMS was built by the [[Centre d'Etude Spatiale des Rayonnements]] of France.<ref name="aeat2000" /><ref name="xmm-instruments-epic" /><ref name="Turner2001" />

=== Visual Monitoring Cameras{{anchor|VMC}} ===
The ''Visual Monitoring Cameras'' (VMC) on the spacecraft were added to monitor the deployment of solar arrays and the sun shield, and have additionally provided images of the thrusters firing and outgassing of the Telescope Tube during early operations. Two VMCs were installed on the Focal Plane Assembly looking forward. The first is FUGA-15, a black and white camera with high [[dynamic range]] and 290 × 290 pixel resolution. The second is IRIS-1, a colour camera with a variable [[exposure time]] and 400 × 310 pixel resolution. Both cameras measure {{convert|6|xx|6|xx|10|cm|in|abbr=on}} and weight {{convert|430|g|abbr=on}}. They use [[active pixel sensor]]s, a technology that was new at the time of ''XMM-Newton''{{'s}} development. The cameras were developed by {{abbr|OIC–Delft|Optronic Instruments and Products–Delft Sensor Systems}} and [[IMEC]], both of Belgium.<ref name="esa19991217"/><ref name="Habinc2000">{{cite conference |url=http://microelectronics.esa.int/vhdl/doc/MonCam.pdf |title=In-flight Results Using Visual Monitoring Cameras |conference=Data Systems in Aerospace. 22–26 May 2000. Montreal, Canada. |first1=Sandi |last1=Habinc |first2=Anders |last2=Karlsson |first3=Willem |last3=Wijmans |first4=David |last4=Jameux |first5=Werner |last5=Ogiers |first6=Lieve |last6=de Vos |display-authors=5 |date=2000 |bibcode=2000ESASP.457...71H}}</ref>

== Ground systems ==
''XMM-Newton'' mission control is located at the [[European Space Operations Centre]] (ESOC) in [[Darmstadt]], Germany. Two [[ground station]]s, located in [[Perth]] and [[Kourou]], are used to maintain continuous contact with the spacecraft through most of its orbit. Back-up ground stations are located in [[Villanueva de la Cañada|Villafranca del Castillo]], [[Santiago]], and [[Dongara]]. Because ''XMM-Newton'' contains no on-board data storage, science data is transmitted to these ground stations in real time.<ref name="xmm-orbit-nav"/>

Data is then forwarded to the [[European Space Astronomy Centre]]{{'s}} Science Operations Centre in Villafranca del Castillo, Spain, where pipeline processing has been performed since March 2012. Data is archived at the ESAC Science Data Centre,<ref name="irac">{{cite web |url=http://nxsa.esac.esa.int/nxsa-web/ |title=Welcome to the XMM-Newton Science Archive |publisher=European Space Agency |date=6 August 2018 |access-date=15 October 2018}}</ref> and distributed to mirror archives at the [[Goddard Space Flight Center]] and the XMM-Newton Survey Science Centre (SSC) at the [[Institut de Recherche en Astrophysique et Planétologie]]. Prior to June 2013, the SSC was operated by the [[University of Leicester]], but operations were transferred due to a withdrawal of funding by the United Kingdom.<ref name="SSC-Leicester"/><ref name="SSC-IRAP">{{cite web |url=http://xmmssc.irap.omp.eu/ |title=XMM-Newton Survey Science Centre |publisher=L'Institut de Recherche en Astrophysique et Planétologie |access-date=31 January 2016}}</ref>

== Observations and discoveries ==
The space observatory was used to discover the [[galaxy cluster]] [[XMMXCS 2215-1738]], 10 billion light years away from Earth.<ref>{{cite press release |url=http://www.sussex.ac.uk/newsandevents/pressrelease/media/media558.html |title=Massive galaxy cluster found 10 billion light years away |publisher=University of Sussex |first=Jacqui |last=Bealing |date=7 June 2006}}</ref>

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<ref name="nature20080919">{{cite news |url=http://www.nature.com/news/2008/080919/full/news.2008.1122.html |title=How they wonder what you are |journal=[[Nature (journal)|Nature]] |first=Geoff |last=Brumfiel |date=19 September 2008 |access-date=12 February 2016 |doi=10.1038/news.2008.1122}}</ref> two orders of magnitude more luminous than that of [[supernova]]e.<ref name="Gansicke2009">{{cite journal |title=SCP 06F6: A Carbon-rich Extragalactic Transient at Redshift ''Z'' ≃ 0.14? |journal=[[The Astrophysical Journal Letters]] |first1=Boris T. |last1=Gänsicke |first2=Andrew J. |last2=Levan |first3=Thomas R. |last3=Marsh |first4=Peter J. |last4=Wheatley |volume=697 |issue=2 |pages=L129–L132 |date=June 2009 |doi=10.1088/0004-637X/697/2/L129 |bibcode=2009ApJ...697L.129G |arxiv=0809.2562|s2cid=14807033 }}</ref>

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.<ref>{{cite news |url=http://www.esa.int/Our_Activities/Space_Science/Neutron_star_bites_off_more_than_it_can_chew |title=Neutron star bites off more than it can chew |publisher=European Space Agency |date=28 June 2011 |access-date=12 February 2016}}</ref><ref name="Bozzo2011">{{cite journal |title=XMM-Newton observations of IGR J18410-0535: the ingestion of a clump by a supergiant fast X-ray transient |journal=[[Astronomy and Astrophysics]] |first1=E. |last1=Bozzo |first2=A. |last2=Giunta |first3=G. |last3=Cusumano |first4=C. |last4=Ferrigno |first5=R. |last5=Walter |first6=S. |last6=Campana |first7=M. |last7=Falanga |first8=G. |last8=Israel |first9=L. |last9=Stella |display-authors=5 |volume=531 |at=A130 |date=July 2011 |doi=10.1051/0004-6361/201116726 |bibcode=2011A&A...531A.130B |arxiv=1106.5125|s2cid=119231893 }}</ref>

In February 2013 it was announced that ''XMM-Newton'' along with [[NuSTAR]] have for the first time measured the spin rate of a [[supermassive black hole]], by observing the black hole at the core of galaxy [[NGC 1365]]. At the same time, it verified the model that explains the distortion of X-rays emitted from a black hole.<ref>{{cite press release |url=http://www.nasa.gov/home/hqnews/2013/feb/HQ_13-063_NuSTAR_Black_Hole_Spin.html |title=NASA's NuSTAR Helps Solve Riddle of Black Hole Spin |publisher=NASA |first1=J.D. |last1=Harrington |first2=Whitney |last2=Clavin |date=27 February 2013 |access-date=20 September 2014 |archive-date=27 May 2013 |archive-url=https://web.archive.org/web/20130527130948/http://www.nasa.gov/home/hqnews/2013/feb/HQ_13-063_NuSTAR_Black_Hole_Spin.html |url-status=dead }}</ref><ref name="Risaliti2013">{{cite journal |title=A rapidly spinning supermassive black hole at the centre of NGC 1365 |journal=[[Nature (journal)|Nature]] |first1=G. |last1=Risaliti |first2=F. A. |last2=Harrison |first3=K. K. |last3=Madsen |first4=D. J. |last4=Walton |first5=S. E. |last5=Boggs |first6=F. E. |last6=Christensen |first7=W. W. |last7=Craig |first8=B. W. |last8=Grefenstette |first9=C. J. |last9=Hailey |first10=E. |last10=Nardini |first11=Daniel |last11=Stern |first12=W. W. |last12=Zhang |display-authors=5 |volume=494 |issue=7438 |pages=449–451 |date=February 2013 |doi=10.1038/nature11938 |bibcode=2013Natur.494..449R |arxiv=1302.7002 |pmid=23446416|s2cid=2138608 }}</ref>

In February 2014, separate analyses extracted from the spectrum of X-ray emissions observed by ''XMM-Newton'' a [[Indirect detection of dark matter#The 3.5 keV line|monochromatic signal around 3.5 keV]].<ref name="Bulbul2014">{{cite journal |title=Detection of an Unidentified Emission Line in the Stacked X-Ray Spectrum of Galaxy Clusters |journal=[[The Astrophysical Journal]] |first1=Esra |last1=Bulbul |first2=Maxim |last2=Markevitch |first3=Adam |last3=Foster |first4=Randall K. |last4=Smith |first5=Michael |last5=Loewenstein |first6=Scott W. |last6=Randall |display-authors=5 |volume=789 |issue=1 |at=13 |date=July 2014 |doi=10.1088/0004-637X/789/1/13 |bibcode=2014ApJ...789...13B |arxiv=1402.2301|s2cid=118468448 }}</ref><ref>{{cite journal |title=Unidentified Line in X-Ray Spectra of the Andromeda Galaxy and Perseus Galaxy Cluster |journal=[[Physical Review Letters]] |first1=Alexey |last1=Boyarsky |first2=Oleg |last2=Ruchayskiy |first3=Dmytro |last3=Iakubovskyi |first4=Jeroen |last4=Franse |volume=113 |issue=25 |at=251301 |date=December 2014 |doi=10.1103/PhysRevLett.113.251301 |bibcode=2014PhRvL.113y1301B |arxiv=1402.4119 |pmid=25554871|s2cid=21406370 }}</ref> This signal is coming from different [[galaxy cluster]]s, and several scenarios of [[dark matter]] can justify such a line. For example, a 3.5 keV candidate annihilating into 2 photons,<ref name="Dudas2014">{{cite journal |title=Generating x-ray lines from annihilating dark matter |journal=[[Physical Review D]] |first1=Emilian |last1=Dudas |first2=Lucien |last2=Heurtier |first3=Yann |last3=Mambrini |volume=90 |issue=3 |at=035002 |date=August 2014 |doi=10.1103/PhysRevD.90.035002 |bibcode=2014PhRvD..90c5002D |arxiv=1404.1927|s2cid=118573978 }}</ref> or a 7 keV dark matter particle decaying into photon and neutrino.<ref name="Ishida2014">{{cite journal |title=7 keV sterile neutrino dark matter from split flavor mechanism |journal=[[Physics Letters B]] |first1=Hiroyuki |last1=Ishida |first2=Kwang Sik |last2=Jeong |first3=Fuminobu |last3=Takahashi |volume=732 |pages=196–200 |date=May 2014 |doi=10.1016/j.physletb.2014.03.044 |bibcode=2014PhLB..732..196I |arxiv=1402.5837|s2cid=119226364 }}</ref>

In June 2021, one of the largest X-ray surveys using the European Space Agency's ''XMM-Newton'' space observatory published initial findings, mapping the growth of 12,000 supermassive black holes at the cores of galaxies and galaxy clusters.<ref>{{cite web |url=https://phys.org/news/2021-06-x-ray-reveals-supermassive-black-holes.html |title=New X-ray map reveals growing supermassive black holes in next-gen survey fields |website=Phys.org |date=8 June 2021 }}</ref>

In November 2025 it was announced that in May 2016 ''XMM-Newton'' had observed the first confirmed [[coronal mass ejection]] on a star other than the sun using it's low frequency array.<ref>{{Cite web |date=November 12, 2025 |title=First confirmed sighting of explosive burst on nearby star |url=https://www.esa.int/Science_Exploration/Space_Science/XMM-Newton/First_confirmed_sighting_of_explosive_burst_on_nearby_star |access-date=2025-11-12 |website=www.esa.int |language=en}}</ref><ref>{{Cite journal |last=Callingham |first=J. R. |last2=Tasse |first2=C. |last3=Keers |first3=R. |last4=Kavanagh |first4=R. D. |last5=Vedantham |first5=H. K. |last6=Zarka |first6=P. |last7=Bellotti |first7=S. |last8=Cristofari |first8=P. I. |last9=Bloot |first9=S. |last10=Konijn |first10=D. C. |last11=Hardcastle |first11=M. J. |last12=Lamy |first12=L. |last13=Pass |first13=E. K. |last14=Pope |first14=B. J. S. |last15=Reid |first15=H. |date=2025-11-12 |title=Radio burst from a stellar coronal mass ejection |url=https://www.nature.com/articles/s41586-025-09715-3 |journal=Nature |language=en |pages=1–5 |doi=10.1038/s41586-025-09715-3 |issn=1476-4687|arxiv=2511.09289 }}</ref>

== See also ==
{{Portal|Spaceflight|Astronomy}}
* [[X-ray astronomy]]
** [[List of X-ray space telescopes]]
* [[List of things named after Isaac Newton]]
* [[List of European Space Agency programmes and missions]]

== References ==
{{reflist |30em}}

== External links ==
{{commons category|XMM-Newton}}
* [http://sci.esa.int/xmm-newton/ ''XMM-Newton'' website] by ESA
* [http://www.esa.int/Our_Activities/Operations/XMM-Newton_operations ''XMM-Newton'' Operations website] by ESA
* [http://xmm.esac.esa.int/ ''XMM-Newton'' Science Operations Centre website] {{Webarchive|url=https://web.archive.org/web/20151213022208/http://xmm.esac.esa.int/ |date=2015-12-13 }} by ESA
* [http://xmm-catalog.irap.omp.eu/ ''XMM-Newton'' Survey Science Centre website] by the L'Institut de Recherche en Astrophysique et Planétologie
* [http://heasarc.gsfc.nasa.gov/docs/xmm/ ''XMM-Newton'' Guest Observer Facility website] {{Webarchive|url=https://web.archive.org/web/20080407142315/http://heasarc.gsfc.nasa.gov/docs/xmm/ |date=2008-04-07 }} by NASA/Goddard Space Flight Center
* [https://www.eoportal.org/satellite-missions/xmm-newton XMM-Newton article on eoPortal by ESA]

{{Space observatories}}
{{ESA projects}}
{{Isaac Newton}}
{{Orbital launches in 1999}}

{{EngvarB|date=February 2016}}

[[Category:Spacecraft launched in 1999]]
[[Category:Satellites orbiting Earth]]
[[Category:European Space Agency satellites]]
[[Category:Space telescopes]]
[[Category:X-ray telescopes]]