View source for SELENE

{{Short description|Japanese lunar orbiter spacecraft}}
{{About||the second SELENE series lunar spacecraft|SELENE-2|other uses|Selene (disambiguation)}}
{{Use mdy dates|date=May 2020|cs1-dates=y}}
{{Expand Japanese|かぐや|date=December 2018}}
{{Infobox spaceflight
| name               = Kaguya
| image              = Selene.gif
| image_caption      = 
| insignia           = kaguya mark.jpg
| mission_type       = Lunar orbiter
| operator           = [[JAXA]]
| COSPAR_ID          = 2007-039A
| SATCAT             = 32054
| mission_duration   = 1 year and 9 months (launch date to decay date)
| spacecraft_bus     = 
| manufacturer       = [[NEC Toshiba Space Systems]]
| dry_mass           = 
| launch_mass        = Total: {{convert|3020|kg}}<br>* Main orbiter (''Kaguya''): {{convert|2914|kg}}<br>* Relay Satellite (''Okina''): {{convert|53|kg}}<br>* VLBI Satellite (''Ouna''): {{convert|53|kg}}<ref name="jaxa20070613"></ref><ref name="SELENE">{{cite web |url=https://ntrs.nasa.gov/api/citations/20220000366/downloads/Ahrens_Kaguya_overview.pdf |title=SELENE/Kaguya |publisher=NASA |access-date=December 2, 2022}}</ref>
| power              = 3,486&nbsp;watts
| instruments        = {{Plainlist}}
* X-ray Spectrometer (XRS)
* [[Gamma-ray spectrometer]] (GRS)
* Multi-band Imager (MI)
* Spectral Profiler (SP)
* Terrain Camera (TC)
* Lunar Radar Sounder (LRS)
* Laser Altimeter (LALT)
* Lunar Magnetometer (LMAG)
* Charged Particle Spectrometer (CPS)
* Plasma energy Angle and Composition Experiment (PACE)
* Radio Science (RS)
* Upper-atmosphere and Plasma Imager (UPI)
* Relay Satellite aboard Okina (RSAT)
* VLBI Radio source aboard Okina and Ouna (VRAD)
* High Definition Television cameras (HDTV)
{{Endplainlist}}|
| launch_date        = {{start-date|September 14, 2007, 01:31:01|timezone=yes}}&nbsp;UTC
| launch_rocket      = [[H-IIA]] 2022 F13
| launch_site        = [[Tanegashima Space Center|Tanegashima]] [[Yoshinobu Launch Complex|Yoshinobu&nbsp;1]]
| launch_contractor  = [[Mitsubishi Heavy Industries|Mitsubishi]]
| disposal_type      = Deorbited (Moon impact)
| decay_date         = {{end-date|June 10, 2009, 18:25|timezone=yes}}&nbsp;UTC|
| orbit_epoch        = September 29, 2007<ref name="satcat">{{cite web |url=http://planet4589.org/space/log/satcat.txt |title=Satellite Catalog |publisher=Jonathan's Space Page |first=Jonathan |last=McDowell |access-date=May 3, 2018}}</ref>
| orbit_reference    = [[Selenocentric orbit|Selenocentric]]
| orbit_periapsis    = {{convert|281|km|mi}}<ref name="satcat"/>
| orbit_apoapsis     = {{convert|231910|km|mi}}<ref name="satcat"/>
| orbit_inclination  = 29.9&nbsp;degrees<ref name="satcat"/>
| orbit_period       = 7109.28&nbsp;seconds<ref name="satcat"/>
| apsis              = selene|
| interplanetary     = {{Infobox spaceflight/IP
   |type                = orbiter
   |object              = [[Moon|Lunar]]
   |orbits              = 
   |arrival_date        = October 3, 2007
   |location            =  {{Lunar coords and quad cat|65.50|S|80.4|E}}<ref>{{cite web|url = https://www.jaxa.jp/press/2009/06/20090611_kaguya_j.html|title = Result of controlled drop of lunar orbiter "KAGUYA (SELENE)"|publisher = JAXA|access-date = June 9, 2024|archive-date = June 9, 2024|archive-url = https://web.archive.org/web/20240609054253/https://www.jaxa.jp/press/2009/06/20090611_kaguya_j.html|url-status = live}}</ref>
 }}
}}
'''SELENE''' ({{IPAc-en|ˈ|s|ɛ|l|ᵻ|n|iː}}; '''Selenological and Engineering Explorer'''), better known in Japan by its nickname {{nihongo|'''Kaguya'''|かぐや}}, was the second Japanese [[Moon|lunar]] orbiter [[spacecraft]] following the [[Hiten (spacecraft)|Hiten]] probe.<ref name=redorbit>{{cite news | url=http://www.redorbit.com/news/space/1066163/kaguya__another_chapter_for_the_lunar_saga/index.html |title=Kaguya – Another Chapter for the Lunar Saga | publisher=Red Orbit |date=September 14, 2007 |access-date=September 14, 2007 |archive-date=2011-05-22  |archive-url=https://web.archive.org/web/20110522040727/http://www.redorbit.com/news/space/1066163/kaguya__another_chapter_for_the_lunar_saga/index.html |url-status=dead }}</ref> Produced by the [[Institute of Space and Astronautical Science]] (ISAS) and the [[National Space Development Agency]] (NASDA), the spacecraft was launched on September 14, 2007. After orbiting the Moon for a year and eight months, the main orbiter was instructed to impact on the lunar surface near the crater [[Gill (lunar crater)|Gill]] on June 10, 2009.<ref name="lunarimpact">{{cite web |url=http://www.kaguya.jaxa.jp/en/communication/KAGUYA_Lunar_Impact_e.htm |title=KAGUYA Lunar Impact |publisher=JAXA |access-date=June 24, 2009}}</ref>

==Nickname==
[[File:Japanese Fairy Book - Ozaki - P118.png|thumb|left|"The Receding Princess" from The Japanese Fairy Book, 1908]]
The orbiter's nickname, Kaguya, was selected by the general public. It comes from the name of a lunar princess in the ancient [[Japanese folktale]] ''[[The Tale of the Bamboo Cutter]]''.<ref name="jaxa_nickname">{{cite web|url=http://www.jaxa.jp/countdown/f13/special/nickname_e.html| title="KAGUYA" selected as SELENE's nickname| access-date=October 13, 2007}}</ref> After their successful release, its sub-satellites, '''Rstar''' and '''Vstar''', were named '''Okina''' and '''Ouna''', also derived from characters in the tale.<ref name="jaxa20071012">{{cite press release | url=http://www.jaxa.jp/press/2007/10/20071012_kaguya_e.html | title=KAGUYA (SELENE) / Result of the Separation of the VRAD Satellite (Vstar) | date=October 12, 2007 | access-date=October 13, 2007 | archive-date=2012-03-20  | archive-url=https://web.archive.org/web/20120320205250/http://www.jaxa.jp/press/2007/10/20071012_kaguya_e.html | url-status=dead }}</ref>

==Mission objectives==
The main scientific objectives of the mission were to:
* Study the origins of the Moon and its [[Moon#Natural history|geologic evolution]]
* Obtain information about the [[Geology of the Moon|lunar surface environment]]

==Launch==
[[Image:H-IIA F13 launching KAGUYA.jpg|thumb|Launch of H-IIA F13 carrying SELENE (Photo by Narita Masahiro)]]
SELENE launched on September 14, 2007, at 01:31:01 UTC on an [[H-IIA]] (Model H2A2022) carrier rocket from [[Tanegashima Space Center]] into a {{convert|281.55|km|adj=on}} ([[perigee]]) / {{convert|232960|km|adj=on}} ([[apogee]]) [[geocentric orbit|geocentric]] [[parking orbit]].<ref>{{cite web | url = http://planetary.org/news/2007/0914_Kaguya_Rockets_Toward_the_Moon.html | title = Kaguya Rockets Toward the Moon | access-date = September 15, 2007 | author = Emily Lakdawalla | date = September 14, 2007 | archive-date = 2012-02-06  | archive-url = https://web.archive.org/web/20120206131248/http://planetary.org/news/2007/0914_Kaguya_Rockets_Toward_the_Moon.html | url-status = dead }}</ref><ref name="jaxa20070919">{{cite web | url=http://www.jaxa.jp/press/2007/09/20070919_sac_h2a-f13.pdf | title=H-IIAロケット13号機による月周回衛星「かぐや」の打上げ結果について（速報） | language=ja |access-date=September 19, 2007 |author=MHI / JAXA}}</ref> The total launch mass was {{convert|3020|kg}}.<ref name="jaxa20070613">{{cite web | url = http://www.jaxa.jp/press/2007/06/20070613_sac_h2a-f13.pdf | title = 平成19年度夏期ロケット打ち上げおよび追跡管制計画書 (Rocket Launch and Tracking Control Plan, Summer 2007) | publisher = MHI / JAXA |language=ja}}</ref><ref name="SELENE"></ref>

The SELENE mission was originally scheduled to launch in 2003, but rocket failures on another mission and technical difficulties delayed the launch until 2007.<ref>{{cite web|url=https://news.bbc.co.uk/2/hi/asia-pacific/6994272.stm|title=Japan launches first lunar probe |date=September 14, 2007|access-date=September 14, 2007 | work=BBC News}}</ref> Launch was planned for August 16, 2007, but was postponed when some electronic components were found to be installed incorrectly.<ref>{{cite web|url=http://www.jaxa.jp/press/2007/07/20070720_kaguya_e.html|title=Launch Postponement of the KAGUYA (SELENE)|date=July 20, 2007|access-date=August 15, 2007}}</ref>

==Lunar operations==
On October 3, it entered an initial {{convert|101|to|11741|km|adj=on}} polar lunar orbit.<ref>{{cite press release | url=http://www.jaxa.jp/press/2007/10/20071005_kaguya_e.html | title=KAGUYA (SELENE) Result of the Lunar Orbit Injection Maneuver (LOI1) – Lunar orbit injection was confirmed| date=October 5, 2007 | access-date=October 5, 2007 | publisher=JAXA | archive-date=2012-05-14  | archive-url=https://web.archive.org/web/20120514023250/http://www.jaxa.jp/press/2007/10/20071005_kaguya_e.html | url-status=dead }}</ref>
On October 9, the relay satellite was released into a {{convert|100|to|2400|km|adj=on}} orbit, while on October 12 the VLBI satellite was released into a {{convert|100|to|800|km|adj=on}} one.<ref name="jaxa20071012" /> Finally, by October 19, the orbiter was in a circular {{convert|100|km|adj=on}} orbit.<ref name="jaxa20071001">{{cite web|url=http://www.jaxa.jp/countdown/f13/index_j.html|title= かぐや/H-IIA13号機 打上げ特設サイト|language=ja|access-date=October 1, 2007}}</ref> The nominal mission duration was one year plus possible extensions.

On October 31, 2007, Kaguya deployed its Lunar Magnetometer, Lunar Radar Sounder, Earth-looking Upper Atmosphere and Plasma Imager. On December 21, 2007, Kaguya began regular operations after all fifteen observation experiments had been satisfactorily verified.

Kaguya completed the planned operation by the end of October 2008 and began extended operations planned to continue through March 2009. It would then be sent into a circular {{convert|50|km|adj=on}} orbit, and finally to an elliptical {{convert|20|to|100|km|adj=on}} one, with a controlled impact occurring by August 2009.<ref>{{cite web |title=月周回衛星「かぐや（SELENE）」の定常運用終了と後期運用計画について |url=http://www.jaxa.jp/press/2008/11/20081105_sac_kaguya.pdf |language=ja |date=November 5, 2008 |access-date=November 5, 2008}}</ref> Because of a degraded [[reaction wheel]], the plan was changed so that on February 1, 2009, the orbit was lowered to {{convert|50|km}} ± {{convert|20|km}},<ref name="JAXA20090218">{{cite web |title=月周回衛星「かぐや（SELENE）」の 状況について |url=http://www.jaxa.jp/press/2009/02/20090218_sac_kaguya.pdf |language=ja |date=February 18, 2009 |access-date=February 22, 2009}}</ref>
and impact with lunar surface occurred at 18:25 UTC on June 10, 2009.<ref name="lunarimpact" />

==Design==
The mission featured three separate spacecraft:

===Main orbiter===
Source:<ref name="jaxa20070613" />
*Shape: [[octagonal prism]]
*Mass: {{convert|2914|kg}}
*Size: 2.1 x 2.1 x 4.8 m (6.9 x 6.9 x 16&nbsp;ft)
*[[Attitude dynamics and control|Attitude control]]: [[Three-axis stabilized]]
*Power: 3.5&nbsp;kW (Max.)
*Mission period: 1 year
*Mission orbit: Circular, {{convert|100|km|adj=on}}
*Inclination: 90 degrees

===Okina (small relay satellite)===
Okina (formerly Rstar) and Ouna (formerly Vstar) were octagonal prisms to support radio science. Okina [[Repeater|relayed]] radio communications between the orbiter and the Earth when the orbiter was behind the Moon. This allowed, for the first time, the direct [[Doppler shift]] measurements needed
to precisely map the gravitational field of the lunar farside; previously, the farside gravity field could only be inferred by nearside measurements. The relay satellite impacted the lunar farside near the [[Mineur (crater)|Mineur D]] crater at 19:46 JST (10:46 UTC) on February 12, 2009.<ref name="JAXA20090218" />

*Function: two-way radio science relay, orbiter-earth
*Mass: {{convert|53|kg}}<ref name="jaxa20070613" />
*Size: 1.0 x 1.0 x 0.65 m (3.3 x 3.3 x 2.1&nbsp;ft)
*Attitude control: [[Spin-stabilized satellite|spin-stabilized]]
*Power: 70 W
*Initial orbit: {{convert|100|to|2400|km}}
*Inclination: 90 degrees

===Ouna (VLBI satellite)===
Ouna used [[Very Long Baseline Interferometry]] as a second way to map the Moon's gravity field. It was especially useful at the [[lunar limb]], where the gravitational acceleration is perpendicular to the line of sight to Earth, making Doppler measurements unsuitable.

*Function: VLBI radio science
*Mass: {{convert|53|kg}}
*Size: 1.0 x 1.0 x 0.65 m (3.3 x 3.3 x 2.1&nbsp;ft)
*Attitude control: spin-stabilized
*Power: 70 W
*Initial orbit: {{convert|100|to|800|km}}
*Inclination: 90 degrees

==Instruments==
[[File:Earth_at_11000_km.jpg|thumb|right|First optical still captured by the onboard HDTV camera. Earth is seen at a distance of 11,000 km.<ref>{{Cite web|url=https://www.darts.isas.jaxa.jp/planet/project/selene/hdtv/pdap/?RETURN_TYPE=HTML&RESOURCE_CLASS=HDTV_PRODUCT&LOCALE=en&DISPLAY_ORDER=PRODUCT_ID|title = PDAP Search Results}}</ref>]]

SELENE carried 13 scientific instruments "to obtain scientific data of the lunar origin and evolution and to develop the technology for the future lunar exploration":<ref name="index">{{cite web |url=http://www.selene.jaxa.jp/index_e.htm |title=Kaguya (SELENE) |access-date=June 25, 2007 |publisher=JAXA}}</ref>

*Terrain camera (TC) (resolution 10 meters [33&nbsp;ft] per pixel)<ref name="lism">{{cite web |url=http://www.selene.jaxa.jp/en/equipment/tc_e.htm |title=LISM [TC, MI, SP] |access-date=June 25, 2007 |work=Kaguya (SELENE) |publisher=JAXA}}</ref>
*[[X-ray]] fluorescence [[spectrometer]] (XRS)
*Lunar [[magnetometer]] (LMAG)
*Spectral profiler (SP) (resolution per pixel: 562 x 400 m [1840 x 1310&nbsp;ft)
*Multi-band imager (MI) (resolution of visible light 20 [66&nbsp;ft] meters per pixel, near-infrared 62 meters [200&nbsp;ft] per pixel)
*[[LIDAR|Laser altimeter]] (LALT)
*Lunar [[radar]] sounder (LRS)
*[[Gamma ray]] spectrometer (GRS)
*[[Charged particle]] spectrometer (CPS)
*[[Plasma (physics)|Plasma]] analyzer (PACE)
*Upper atmosphere and plasma imager (UPI)
*Radio wave repeater (RSAT) aboard Okina
*Radio wave source for VLBI (VRAD) aboard Okina and Ouna

Two 2.2 megapixel CCD [[High-definition television|HDTV]] [[camera]]s, one wide-angle and one telephoto, were also on board, primarily for public outreach.<ref>{{cite web |url=http://www.kaguya.jaxa.jp/en/equipment/hdtv_e.htm |title=KAGUYA (SELENE) – Mission Instruments – HDTV |access-date=March 1, 2009}}</ref> The HDTV system, developed by [[NHK]] (Japan Broadcasting Corporation), produced over 1.3 TB of video and stills over 19 months.<ref>{{cite journal|url=https://www.lpi.usra.edu/meetings/lpsc2009/pdf/2540.pdf|title=Results of High-Definition Television System (HDTV) on Board SELENE (KAGUYA)|journal=40th Lunar and Planetary Science Conference (2009)|access-date=9 December 2022}}</ref>

JAXA collected names and messages that were carried on SELENE through their "Wish Upon the Moon" campaign.<ref>{{cite press release | title =Send a New Year's Message to the Moon on Japan's SELENE Mission: Buzz Aldrin, Ray Bradbury and More Have Wished Upon the Moon | publisher =The Planetary Society | date =January 11, 2007 | url =http://www.planetary.org/about/press/releases/2007/0111_Send_a_New_Years_Message_to_the_Moon.html | access-date =July 14, 2007 | archive-date =2012-02-12  | archive-url =https://web.archive.org/web/20120212094535/http://www.planetary.org/about/press/releases/2007/0111_Send_a_New_Years_Message_to_the_Moon.html | url-status =dead }}</ref> 412,627 names and messages were printed on a sheet measuring 280&nbsp;mm x 160&nbsp;mm (11 x 6.3 in) at 70 [[micrometre|μm]] (0.0003&nbsp;in) per character. The sheet was installed under the [[photovoltaic module]]s and cooling panels beneath the multi-layered insulation.<ref>{{cite web |url=http://www.isas.jaxa.jp/j/new/event/selene_camp/topics.shtml |title=セレーネ「月に願いを!」(SELENE "Wish Upon the Moon!") |access-date=July 14, 2007 |date=2007 |publisher=JAXA |language=ja |url-status=dead |archive-url=https://web.archive.org/web/20070404082251/http://www.isas.jaxa.jp/j/new/event/selene_camp/topics.shtml |archive-date=April 4, 2007 }}</ref>

==Results==
Major results include:
*Improved lunar global topography maps.<ref>{{cite journal |title=Lunar Global Shape and Polar Topography Derived from Kaguya-LALT Laser Altimetry |author=H. Araki |display-authors=etal |journal=Science |issue=5916 |pages=897–900 |date=February 13, 2009 |doi=10.1126/science.1164146 |volume=323 |pmid=19213910|bibcode = 2009Sci...323..897A |s2cid=2115707 }}</ref> This detailed altitude and geological data was provided to Google for free to make Google Moon 3-D.
*Detailed gravity map of the [[far side of the Moon]].<ref>{{cite journal |title=Farside Gravity Field of the Moon from Four-Way Doppler Measurements of SELENE (Kaguya) |author=N. Namiki |display-authors=etal |journal=Science |issue=5916 |pages=900–905 |date=February 13, 2009 |doi=10.1126/science.1168029 |volume=323 |pmid=19213911|bibcode = 2009Sci...323..900N |s2cid=5306227 }}</ref>
*First optical observation of the permanently shadowed interior of the crater [[Shackleton (crater)|Shackleton]] at the lunar south pole.<ref>{{cite journal |title=Lack of Exposed Ice Inside Lunar South Pole Shackleton Crater |author=J. Haruyama |display-authors=etal |journal=Science |issue=5903 |pages=938–939 |date=November 7, 2008 |doi=10.1126/science.1164020 |volume=322 |pmid=18948501 |bibcode=2008Sci...322..938H|s2cid=20749838 |doi-access=free }}</ref>
*Evidence of Earth's oxygen being transported to the Moon via [[magnetosphere|magnetospheric]] ions.<ref>{{cite journal |first1=Kentaro |last1=Terada |first2=Shoichiro |last2=Yokota |first3=Yoshifumi |last3=Saito |first4=Naritoshi |last4=Kitamura |first5=Kazushi |last5=Asamura |first6=Masaki |last6=Nishino |date=January 30, 2017 |title=Biogenic oxygen from Earth transported to the Moon by a wind of magnetospheric ions |journal=Nature Astronomy |volume= 1|issue= 2|pages= 0026|doi=10.1038/s41550-016-0026 |bibcode=2017NatAs...1E..26T |s2cid=85560607 }}</ref>

==Other lunar probes==
SELENE was part of a renewed global interest in lunar exploration; it was "the largest lunar mission since the [[Apollo program]]".<ref>{{cite web |url=http://www.jaxa.jp/projects/sat/selene/index_e.html |title=SELENE: The largest lunar mission since the Apollo program |access-date=April 21, 2008 |archive-date=2013-10-24  |archive-url=https://web.archive.org/web/20131024124342/http://www.jaxa.jp/projects/sat/selene/index_e.html |url-status=dead }}</ref> It followed Japan's first lunar probe, [[Hiten (spacecraft)|Hagoromo]], launched in 1990.<ref name=redorbit /><ref>{{cite web | url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1990-007A | title=Hiten | publisher=[[NASA]] | access-date=September 14, 2007}}</ref> China launched its [[Chang'e 1]] lunar explorer on October 24, 2007, followed by India's October 22, 2008 launch of [[Chandrayaan-1]] and the United States [[Lunar Reconnaissance Orbiter]] in June 2009. The United States, European countries ([[ESA]]), Russia, Japan, India and China are planning [[List of future lunar missions|future crewed lunar exploration missions]] or [[lunar outpost]] construction on the Moon between 2018 and 2025.<ref>{{cite web |url=http://thomas.loc.gov/cgi-bin/query/z?c110:H.R.6063: |title=NASA Authorization Act of 2008 – Section 404 – Lunar Outpost |publisher=[[Library of Congress]] |date=October 22, 2008 |access-date=2008-10-22  |archive-date=2016-07-04  |archive-url=https://web.archive.org/web/20160704213213/http://thomas.loc.gov/cgi-bin/query/z?c110:H.R.6063: |url-status=dead }}</ref>

{{-}}

==See also==
{{Portal|Spaceflight}}
*[[SELENE-2]]
*[[List of missions to the Moon]]
*[[Exploration of the Moon]]

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

==External links==
{{Wikinews|Japan's lunar probe performing 'smoothly' after successful launch}}
*{{in lang|en}} [http://www.selene.jaxa.jp/index_e.htm Official project site], JAXA
*{{in lang|en}} [http://www.jaxa.jp/countdown/f13/index_e.html Official launch information site], JAXA
*[https://web.archive.org/web/20041103152540/http://solarsystem.nasa.gov/missions/profile.cfm?MCode=SELENE SELENE Mission Profile] by [http://solarsystem.nasa.gov NASA's Solar System Exploration]
*{{in lang|en}} [https://web.archive.org/web/20091014064642/http://www.isas.jaxa.jp/e/enterp/missions/kaguya/index.shtml SELENE overview], ISAS/JAXA
*{{in lang|en}} [https://www.youtube.com/user/jaxachannel#grid/user/DA9C6AA8E11F7E56 Official YouTube channel], JAXA
*{{in lang|en}} [http://ltvt.wikispaces.com/Kaguya+Impact June 10th impact location] {{Webarchive|url=https://web.archive.org/web/20130718094036/http://ltvt.wikispaces.com/Kaguya+Impact |date=2013-07-18  }}
*{{in lang|en}} [https://web.archive.org/web/20090503174720/http://www.nec.com/global/solutions/space/satellite_systems/kaguya.html NEC Corporation's Kaguya page], [[NEC Corporation]]
*[https://web.archive.org/web/20100108120541/http://wms.selene.jaxa.jp/selene_viewer/en/observation_mission/tc/037/tc_037_last_operation.html JAXA Link] – Video 12 min. before impact – close surface flyover

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

{{DEFAULTSORT:Selene}}
[[Category:Missions to the Moon]]
[[Category:Japanese space probes]]
[[Category:Japanese Lunar Exploration Program]]
[[Category:LQ30 quadrangle]]
[[Category:Space probes launched in 2007]]
[[Category:Spacecraft that orbited the Moon]]
[[Category:Spacecraft that impacted the Moon]]
[[Category:Spacecraft launched by H-II rockets]]
[[Category:2009 on the Moon]]