View source for Chang'e 1

{{Short description|Chinese lunar probe launched in 2007}}
{{Infobox spaceflight
| name                  = Chang'e 1
| image                 = Chang e 1.jpg
| image_caption         =
| mission_type          = Lunar orbiter<ref>{{cite web | url=http://english.sina.com/technology/1/2007/1024/129176.html | title=China's first lunar probe Chang'e-1 blasts off | publisher=[[SINA Corporation]] | date=October 24, 2007 | access-date=2007-10-24}}</ref><ref name="deorbit"/>
| operator              = [[China National Space Administration]]
| COSPAR_ID             = 2007-051A
| SATCAT                =
| website               =
| mission_duration      = Planned: 1&nbsp;year <br />Achieved: 1&nbsp;year, 4&nbsp;months, 4&nbsp;days
| spacecraft_bus        =
| manufacturer          =
| dry_mass              =
| launch_mass           = 2,350 kg<ref>{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2007-051A |title=Chang'e 1 |publisher=[[NASA Space Science Data Coordinated Archive]] |access-date=November 30, 2022}}</ref>
| power                 =
| launch_date           = {{start-date|24 October 2007, 10:05:04.602|timezone=yes}}&nbsp;UTC
| launch_rocket         = [[Long March 3A|Chang Zheng 3A]]
| launch_site           = [[Xichang Satellite Launch Center|Xichang]] [[Xichang Launch Complex 3|LC-3]]
| launch_contractor     =
| disposal_type         = Deorbited (Moon impact)
| decay_date            = {{end-date|1 March 2009, 08:13:10|timezone=yes}}&nbsp;UTC
| orbit_epoch           =
| orbit_reference       = [[selenocentric orbit|Selenocentric]]
| orbit_periapsis       = {{convert|200|km|mi}}
| orbit_apoapsis        = {{convert|200|km|mi}}
| orbit_inclination     = 64&nbsp;degrees
| orbit_period          = 127&nbsp;minutes
| apsis                 = selene
|interplanetary         =
 {{Infobox spaceflight/IP
  |type                = orbiter
  |object              = Lunar
  |orbits              =
  |arrival_date        = 5 November 2007
  |location            = {{Lunar coords and quad cat|1.50|S|52.36|E}}
 }}
| next_mission          = [[Chang'e 2]]
| programme             = '''[[Chinese Lunar Exploration Program]]'''
}}

'''Chang'e 1''' ({{IPAc-en|pron|tʃ|æ|ŋ|'|ʌ}}; {{zh|s=嫦娥一号|t=嫦娥一號|p=Cháng'é yī hào}}) was an [[Robotic spacecraft|uncrewed]] Chinese [[Moon|lunar]]-orbiting [[spacecraft]], part of the first phase of the [[Chinese Lunar Exploration Program]]. The spacecraft was named after the Chinese Moon goddess, [[Chang'e]].

Chang'e 1 was launched on 24 October 2007 at 10:05:04 [[Coordinated Universal Time|UTC]] from [[Xichang Satellite Launch Center]].<ref>{{cite web|url=http://news.xinhuanet.com/english/2007-10/24/content_6937622.htm |archive-url=https://web.archive.org/web/20071025235924/http://news.xinhuanet.com/english/2007-10/24/content_6937622.htm |url-status=dead |archive-date=October 25, 2007 | title=China's 1st Moon orbiter enters Earth orbit | publisher=[[Xinhua News Agency]] | date=October 24, 2007 | access-date=2007-10-24}}</ref> It left [[lunar transfer orbit]] on 31 October and entered [[lunar orbit]] on 5 November.<ref>{{cite web |url=http://www.efluxmedia.com/news_Chinas_Change_I_Enters_Moon_Orbit_10279.html |title= China's Chang'e-I Enters Moon Orbit|website=www.efluxmedia.com |archive-url=https://web.archive.org/web/20071107081712/http://www.efluxmedia.com/news_Chinas_Change_I_Enters_Moon_Orbit_10279.html |archive-date=November 7, 2007}}</ref>
The first picture of the Moon was relayed on 26 November 2007.<ref>{{cite web |url=http://www.cnsa.gov.cn/n615709/n620682/n639462/132125.html |title=China publishes first Moon picture |publisher=China National Space Administration |date=November 26, 2007 |access-date=2007-11-26 |url-status=dead |archive-url=https://web.archive.org/web/20071128012548/http://www.cnsa.gov.cn/n615709/n620682/n639462/132125.html |archive-date=November 28, 2007 }}</ref> On 12 November 2008, a map of the entire lunar surface was released, produced from data collected by Chang'e 1 between November 2007 and July 2008.<ref>{{cite web | url=http://mil.news.sina.com.cn/s/2008-11-12/1559529860.html | title=China publishes first map of whole lunar surface | date=12 November 2008 | access-date=2008-11-12}}</ref><ref name="results">{{cite web | url=http://www.cjss.ac.cn/qikan/manage/wenzhang/2010-05-02.pdf | title=Chang'E-1 Lunar Mission: An Overview and Primary Science Results | access-date=2011-08-23 | archive-date=2016-11-09 | archive-url=https://web.archive.org/web/20161109223050/http://www.cjss.ac.cn/qikan/manage/wenzhang/2010-05-02.pdf | url-status=dead }}</ref>

The mission was scheduled to continue for a year, but was later extended and the spacecraft operated until 1 March 2009, when it was taken out of orbit. It impacted the surface of the Moon at 08:13 UTC.<ref name="deorbit">{{cite web|url=http://news.xinhuanet.com/english/2009-03/01/content_10923205.htm |archive-url=https://web.archive.org/web/20090302170937/http://news.xinhuanet.com/english/2009-03/01/content_10923205.htm |url-status=dead |archive-date=March 2, 2009 | title=China's lunar probe Chang'e-1 impacts Moon | last=Guodong | first=Du | date=2009-03-01 | publisher=Xinhua | access-date=2009-03-01}}</ref> Data gathered by Chang'e 1 was used to create an accurate and high resolution 3-D map of the lunar surface.<ref name="atimes.com">[https://web.archive.org/web/20100418193148/http://www.atimes.com/atimes/China/LD16Ad01.html "China's map leaps over the moon"] ''Asia Times''</ref> Chang'e 1 was the first lunar probe to conduct passive, multi-channel, microwave remote sensing of the Moon by using a microwave radiometer.<ref name="directory.eoportal.org">{{cite web|url=https://directory.eoportal.org/web/eoportal/satellite-missions/c-missions/chang-e-1|title=Chang'e-1 – eoPortal Directory – Satellite Missions|website=directory.eoportal.org}}</ref>

Its sister orbital probe [[Chang'e 2]] was launched on 1 October 2010.<ref>{{cite web|url=http://www.bbc.co.uk/zhongwen/simp/china/2010/10/101001_china_satellite_moon.shtml |title=BBC 中文网 – 两岸三地 – 嫦娥二号奔月有助提升军事威慑力 |publisher=Bbc.co.uk |date=2010-10-01 |access-date=2013-11-16}}</ref>

== Overview ==

The [[Chinese Lunar Exploration Program]] is designed to be conducted in four <ref name='Jan 2019 press conference'>[https://www.youtube.com/watch?v=v7FiaHwv-BI Chang'e 4 press conference]. CNSA, broadcast on 14 January 2019.</ref> phases of incremental technological advancement: The first is simply reaching lunar orbit, a task completed by Chang'e 1 in 2007 and [[Chang'e 2]] in 2010. The second is landing and roving on the Moon, as [[Chang'e 3]] did in 2013 and [[Chang'e 4]] did in 2019. The third is collecting lunar samples from the near-side and sending them to Earth, a task for the [[Chang'e 5]] and [[Chang'e 6]] missions. The fourth phase consists of development of a robotic research station near the Moon's south pole.<ref name='Jan 2019 press conference'/><ref name='Planning by 2018'>[http://epizodsspace.airbase.ru/bibl/inostr-yazyki/Chinese_Journal_of_Space_Science/2018/5/Xu_et_al_China's_Planning_---_before_2030_Chin_J_Space_Sci_38_(2018).pdf China's Planning for Deep Space Exploration and Lunar Exploration before 2030]. (PDF) XU Lin, ZOU Yongliao, JIA Yingzhuo. ''Space Sci''., 2018, 38(5): 591-592. {{doi|10.11728/cjss2018.05.591}}</ref><ref>[http://adsabs.harvard.edu/abs/2018cosp...42E3886Z A Tentative Plan of China to Establish a Lunar Research Station in the Next Ten Years]. Zou, Yongliao; Xu, Lin; Jia, Yingzhuo. 42nd COSPAR Scientific Assembly. Held 14–22 July 2018, in Pasadena, California, USA, Abstract id. B3.1-34-18.</ref> The program aims to facilitate a crewed lunar landing in the 2030s and to possibly build an outpost near the south pole.<ref>[https://qz.com/1262581/china-lays-out-its-ambitions-to-colonize-the-moon-and-build-a-lunar-palace/ China lays out its ambitions to colonize the moon and build a "lunar palace"]. Echo Huang, ''Quartz''. 26 April 2018.</ref>

== Objectives ==
The Chang'e 1 mission had four major goals:<ref name="results" /><ref>{{cite web | url = http://www.esa.int/esaCP/SEMPM53Z28F_index_0.html | title = Chang'e-1 – new mission to Moon lifts off | publisher = [[European Space Agency]] | access-date=2007-10-24}}</ref>

# Obtaining three-dimensional images of the landforms and geological structures of the [[lunar surface]], so as to provide a reference for planned future soft landings. The orbit of Chang'e 1 around the Moon was designed to provide complete coverage, including areas near the north and south poles not covered by previous missions.
# Analysing and mapping the abundance and distribution of various chemical elements on the lunar surface as part of an evaluation of potentially useful resources on the Moon. China hopes to extend the number of elements studied to 14 ([[potassium]] (K), [[thorium]] (Th), [[uranium]] (U), [[oxygen]] (O), [[silicon]] (Si), [[magnesium]] (Mg), [[aluminium]] (Al), [[calcium]] (Ca), [[tellurium]] (Te), [[titanium]] (Ti), [[sodium]] (Na), [[manganese]] (Mn), [[chromium]] (Cr), and [[lanthanum]] (La)),<ref name=huixian/> compared with the 10 elements (K, U, Th, Fe ([[iron]]), Ti, O, Si, Al, Mg, and Ca)<ref>{{cite journal | journal = Science | date = 1998 | volume = 281 | issue = 5382 | pages = 1484–1489 | doi = 10.1126/science.281.5382.1484 | title = Global Elemental Maps of the Moon: The Lunar Prospector Gamma-Ray Spectrometer | author = D. J. Lawrence | display-authors = 4 | author2 = W. C. Feldman | author3 = B. L. Barraclough | author4 = A. B. Binder | author5 = R. C. Elphic | author6 = S. Maurice | author7 = D. R. Thomsen | pmid = 9727970 | bibcode=1998Sci...281.1484L| doi-access = free }}</ref> previously probed by [[NASA]]'s [[Lunar Prospector]].
# Probing the features of the lunar soil and assessing its depth, as well as the amount of [[helium-3]] (³He) present.<ref name=huixian/>
# Probing the space environment between 40,000&nbsp;km. (24854.8&nbsp;mi) and 400,000&nbsp;km (248548.5&nbsp;mi) from the Earth, recording data on the solar wind and studying the impact of solar activity on the Earth and the Moon.

In addition, the lunar probe engineering system, composed of five major systems – the satellite system, the launch vehicle system, the launch site system, the monitoring and control system and the ground application system – accomplished five goals:

* Researching, developing and launching China's first lunar probe
* Mastering the basic technology of placing satellites in lunar orbit
* Conducting China's first scientific exploration of the Moon
* Initially forming a lunar probe space engineering system
* Accumulating experience for the later phases of China's lunar exploration program

== Mission ==

According to the schedule, detailed design of the first program milestone was completed by September 2004. Research and development of a prototype probe and relevant testing of the probe were finished before the end of 2005. Design, manufacture, general assembly, test and ground experiments of the lunar orbiter were finished before December 2006.{{citation needed|date=October 2017}}

Originally scheduled for April 2007, the launch was postponed until October as this was "a better time for sending a satellite into the Moon's orbit".<ref>{{cite web | url=http://english.cri.cn/2906/2007/03/15/1261@205784.htm | archive-url=https://web.archive.org/web/20070317225442/http://english.cri.cn/2906/2007/03/15/1261@205784.htm | url-status=dead | archive-date=March 17, 2007 | title=Chang'e-1 Satellite Launch Delayed | publisher=[[China Radio International]] | date=March 15, 2007 | access-date=2007-10-24}}</ref> Chang'e 1 was launched  by a [[Long March 3A]] rocket at 10:05 GMT on October 24, 2007, from [[Xichang Satellite Launch Center]] in [[Sichuan]] Province.

After liftoff, Chang'e 1 made three orbits around the Earth, a burn at [[apsis|perigee]] extending the orbit's [[apsis|apogee]] further each time, until a final [[translunar injection]] burn placed it on course for the Moon on October 31, 2007.  Another burn placed it in a [[polar orbit]] around the Moon, with burns at the [[Apsis#Terminology|periselenium]] of the first three orbits decreasing the [[Apsis#Terminology|aposelenium]] until it entered a final circular orbit. Lunar orbit insertion was achieved on the November 5, 2007. To mark this occasion, the probe transmitted 30 classical Chinese songs and musical pieces, including "My Motherland", "The Song of the Yangtze River", and "High Mountains and Flowing Water".{{citation needed|date=October 2017}}

The probe was remotely controlled from stations at [[Qingdao]] and [[Kashgar]], as the first use of the [[Chinese Deep Space Network]].  The [[ESA]] [[Maspalomas Station|Maspalomas Tracking Station]] was also used to transmit signals to and from the probe.{{citation needed|date=October 2017}}

The first pictures of the Moon were relayed on November 26, 2007. The probe was designed to orbit the Moon for one year,<ref name=huixian>{{cite journal
| title=Scientific objectives and payloads of Chang'E-1 lunar satellite
| author=Sūn Huīxiān (孙辉先)
| author2=Dài Shùwǔ (代树武)
| author3=Yáng Jiànfēng (杨建峰)
| author4=Wú Jì (吴季) 
| author5=Jiāng Jǐngshān (姜景山)
| name-list-style=amp
| journal=Journal of Earth System Science
| date=2005
| volume=114
| pages=789–794
| url=http://www.ias.ac.in/jessci/dec2005/ilc-25.pdf
| doi=10.1007/BF02715964
| issue=6
|bibcode = 2005JESS..114..789H | s2cid=128428662
}}</ref> but operations were later extended, and it remained in lunar orbit until March 1, 2009.

==End of mission==
On 1 March 2009, at 08:13:10 UTC, Chang'e 1 crashed onto the surface of the Moon, ending its mission. According to the State Administration of Science, Technology and Industry for National Defense (China), this was a planned and controlled impact.<ref name="AP">{{cite news | url=http://usatoday30.usatoday.com/tech/science/space/2009-03-02-china-lunar-crash_N.htm | title=China lunar probe mission ends with planned crash | agency=Associated Press | work=USA Today|access-date=2009-03-02 | date=2009-03-02}}</ref> Impact point was {{Coord|1.50|S|52.36|E|globe:Moon|display=inline}}.<ref>{{cite web|url = https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2007-051A|title = NASA NSSDC Master Catalog – Chang'e 1|access-date = 2011-01-01}}</ref><ref>{{cite web|url = http://english.peopledaily.com.cn/90001/90781/90876/6603492.html|website= China People's Daily Online | date=2 March 2009 |title=Chang'e-1 impacts Moon (coordinates) |access-date = 2011-01-01}}</ref><ref>{{cite news | title=Smackdown | work=Aviation Week & Space Technology | date=9 March 2009 | volume=70 | issue=10 | page=16 }}</ref>  During its orbital mission the probe transmitted 1,400 gigabits or 175 gigabytes (GB) of data.<ref>{{Cite web|title=Chang'e-1 - eoPortal Directory - Satellite Missions|url=https://directory.eoportal.org/web/eoportal/satellite-missions/c-missions/chang-e-1|access-date=2021-11-18|website=directory.eoportal.org}}</ref>

== Design and instrumentation ==
{{unreferenced section|date=October 2017}}
The Chang'e 1 spacecraft had a mass of {{convert|2350|kg}}, with a {{convert|130|kg|adj=on}} payload, carrying 24 instruments including a [[charge-coupled device]] (CCD) [[stereo camera]], microprobe instruments, and a high-energy solar particle detector.

* Stereo camera with an [[optical resolution]] of {{convert|120|m}} and [[spectrometer]] imager operating at [[wavelength]]s of {{convert|0.48|to(-)|0.96|µm|angstrom|abbr=on}}
* Laser [[altimeter]]  with {{convert|1064|nm|nm|adj=on|disp=out}}, {{convert|150|mJ|mJ|abbr=on|disp=out|lk=out}} laser, a range resolution of {{convert|1|m}} and a [[Gaussian beam#Beam parameters|spot size]] of {{convert|300|m}}
* Imaging spectrometer
* Gamma and X-ray spectrometer working in an energy range of 0.5 to 50 [[Electronvolt|keV]] for [[X-rays]] and 300 keV to 9 MeV for [[gamma ray]]s
* [[Microwave radiometer]] detecting 3, 7.8, 19.35 and 37 [[Hertz|GHz]] with a maximal penetration depth of 30, 20, 10, 1 m (98.4, 65.6, 32.8, 3.3&nbsp;ft) and a [[Temperature|thermal]] resolution of 0.5 K
* [[High energy particle]] detector and two [[solar wind]] detectors capable of the detection of [[electron]]s and heavy [[ion]]s up to 730 MeV

== Achievements ==

* Chang'e 1 created an accurate and high resolution 3-D map ever of the lunar surface.
* Chang'e 1 conducted world's first passive, multi-channel, microwave remote sensing of the Moon.<ref name="directory.eoportal.org"/>

==See also==
{{Portal|Spaceflight}}
* [[Chinese space program]]
** [[Chinese Lunar Exploration Program]] (CLEP) 
* [[Exploration of the Moon]]
* [[List of missions to the Moon]]
* [[List of artificial objects on the Moon]]

==References==
{{Reflist|30em}}

==External links==
{{Commons category}}
{{wikinews|China launches space probe to the Moon}}
* [https://web.archive.org/web/20071015034940/http://www.clep.org.cn/ CLEP Official site]
* [https://web.archive.org/web/20071028145842/http://solarsystem.nasa.gov/missions/profile.cfm?MCode=CHANGE1 Chang'e 1 Mission Profile] by [http://solarsystem.nasa.gov NASA's Solar System Exploration]
* [https://web.archive.org/web/20070408085556/http://astronautix.com/craft/change.htm Encyclopedia Astronautica]

{{Moon spacecraft}}
{{CLEP}}
{{Chinese spacecraft}}
{{Chinese space program}}
{{Solar System probes}}
{{Orbital launches in 2007}}

[[Category:Chinese Lunar Exploration Program]]
[[Category:Missions to the Moon]]
[[Category:Chinese space probes]]
[[Category:Space probes launched in 2007]]
[[Category:2007 in China]]
[[Category:Spacecraft that impacted the Moon]]
[[Category:2009 on the Moon]]
[[Category:Spacecraft launched by Long March rockets]]