Tiandu
{{Short description|Chinese space satellites}}
{{Infobox spaceflight
| name = Tiandu
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| image_upright = 1.0
| mission_type = Technology demonstration
| operator = Deep Space Exploration Laboratory
CNSA
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| mission_duration = {{time interval|20 March 2024 00:31|show=ymd|sep=,}} (in progress)
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| spacecraft = Tiandu
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| manufacturer = Deep Space Exploration Laboratory
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| launch_date = 20 March 2024, 00:31 UTC{{cite web|title=China launches Queqiao-2 relay satellite to support moon missions|url=https://spacenews.com/china-launches-queqiao-2-relay-satellite-to-support-moon-missions/|website=Space.com|access-date=20 March 2024}}
| launch_rocket = Long March 8{{cite web|title=China launches Queqiao-2 relay satellite to support moon missions|url=https://spacenews.com/china-launches-queqiao-2-relay-satellite-to-support-moon-missions/|website=Space.com|access-date=20 March 2024}}
| launch_site = Wenchang Space Launch Site LC-2{{cite web|title=China launches Queqiao-2 relay satellite to support moon missions|url=https://spacenews.com/china-launches-queqiao-2-relay-satellite-to-support-moon-missions/|website=Space.com|access-date=20 March 2024}}
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| orbit_reference = Selenocentric elliptic orbit
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| apsis = selene
|interplanetary = {{Infobox spaceflight/IP | type = orbiter | object = Lunar | component = | arrival_date = 24 March 2024, 17:43 UTC{{Cite web |last=Jones |first=Andrew |date=2024-03-25 |title=China's Queqiao-2 relay satellite enters lunar orbit |url=https://spacenews.com/chinas-queqiao-2-relay-satellite-enters-lunar-orbit/ |access-date=2024-03-26 |website=SpaceNews |language=en-US}} | location = | distance = }}
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Tiandu satellites are a pair of Chinese Lunar Exploration Program's lunar navigation and communications test satellites based on Queqiao-2 relay satellite technology.{{Cite web |title=Tiandu 1, 2 |url=https://space.skyrocket.de/doc_sdat/tiandu-1.htm |access-date=2024-03-23 |website=Gunter's Space Page |language=en}}{{Cite web |author1=Andrew Jones |date=2023-05-09 |title=China to launch communications relay satellite to the moon in early 2024 |url=https://www.space.com/china-moon-far-side-relay-satellite-2024-queqiao-2 |access-date=2024-03-23 |website=Space.com |language=en}}{{Cite web |title=MSN |url=https://www.msn.com/ |access-date=2024-03-23 |website=www.msn.com}}
Design and development
Tiandu satellites will perform navigation and communications technology verification experiments while flying in formation in lunar orbit. Satellite-to-ground laser ranging as well as intersatellite microwave ranging techniques will also be tested.{{Cite web |date=2024-02-04 |title=Testing, testing … China to test new satellite tech for Chang'e 6 lunar mission |url=https://www.scmp.com/news/china/science/article/3250884/testing-testing-china-try-out-new-satellite-tech-change-6-lunar-mission |access-date=2024-03-23 |website=South China Morning Post |language=en}}
The Tiandu satellites' mission is to inform the design of China's proposed Queqiao lunar navigation and communication array. Supporting services for lunar surface operations would be provided by such system. Line-of-sight communications limits affect uncrewed and crewed operations on the Moon, especially at the lunar south pole, an area of great interest, or the lunar far side.{{Cite web |last=Litvinov |first=Nikita |date=2024-02-08 |title=China will launch experimental satellites to the Moon |url=https://universemagazine.com/en/china-prepares-to-build-a-lunar-navigation-and-communication-system/ |access-date=2024-03-23 |website=Журнал The Universemagazine Space Tech |language=en-US}}
The {{cvt|61|kg}} Tiandu-1 carries a Ka dual-band integrated communication payload, a laser retroreflector, a space router and other payloads. The {{cvt|15|kg}} Tiandu-2 carries a communication payload and navigation devices.{{Cite web |last=郭凯 |title=China set to launch two experimental satellites |url=https://www.chinadaily.com.cn/a/202402/04/WS65bf0490a3104efcbdae9908.html |access-date=2024-03-23 |website=www.chinadaily.com.cn}}
Mission
The mission was launched together as a single probe with Queqiao 2 in 2024 on a Long March 8 rocket.{{Cite web |title=China launches Queqiao-2 as key relay communication platform for future lunar missions - China Military |url=http://eng.chinamil.com.cn/CHINA_209163/TopStories_209189/16295620.html |access-date=2024-03-23 |website=eng.chinamil.com.cn}}
After launch, the two satellites (while being attached to each other) underwent lunar orbit insertion on 24 March 2024 at 17:43 UTC and entered a large elliptical orbit around the Moon.{{Cite web |last=Jones |first=Andrew |date=2024-03-25 |title=China's Queqiao-2 relay satellite enters lunar orbit |url=https://spacenews.com/chinas-queqiao-2-relay-satellite-enters-lunar-orbit/ |access-date=2024-03-26 |website=SpaceNews |language=en-US}} In that large elliptical orbit around the Moon, they separated on 3 April 2024{{Cite web |title=探月工程里程碑：天都二号卫星成功应用冷气微推进系统 |url=http://mp.weixin.qq.com/s?__biz=MzA4ODM1ODU0OA==&mid=2653749333&idx=2&sn=6a400906c49236d7a7a1f06fb14e4681&chksm=8bf2cbaebc8542b839ea8a8e55b2003b8049540daccf37c1b96cfe9a6ed8aae7d25cba89f35f#rd |access-date=2024-04-04 |website=Weixin Official Accounts Platform}} and later satellite-to-ground laser ranging are inter-satellite microwave ranging are to be carried out by these satellites via high-precision lunar orbit determination technology.{{cite web|url= https://www.space.com/china-moon-far-side-relay-satellite-2024-queqiao-2 |title= China to launch communications relay satellite to the moon in early 2024 |website=Space.com |date=10 May 2023 |first= Andrew |last=Jones }}{{Cite web |title=我国将发射"天都一号""天都二号"探月卫星-新华网 |url=http://www.news.cn/20240203/0dabcf92cf804b47b1c992d344336e51/c.html |access-date=2024-03-20 |website=www.news.cn}}{{Cite web |author1=Andrew Jones |date=2022-03-31 |title=China has big plans for its new Tiandu space exploration laboratory |url=https://www.space.com/china-tiandu-deep-space-exploration-laboratory |access-date=2024-03-23 |website=Space.com |language=en}}
References
{{Reflist}}
{{Moon spacecraft}}
{{CLEP}}
{{Chinese spacecraft}}
{{Chinese space program}}
{{Solar System probes}}
{{Orbital launches in 2024}}
{{2024 in space}}
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Category:Chinese Lunar Exploration Program
Category:Spacecraft launched by Long March rockets
Category:Spacecraft using halo orbits
Category:Satellites orbiting the Moon
Category:Space probes launched in 2024
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