Chang'e-1

Chang'e-1
Artist's impression of Chang'e-1
NSSDC ID	2007-051A
Mission goal	Earth moon
Client	National Space Agency (CNSA)
Manufacturer	Chinese Academy of Space Technology (CAST)
Launcher	CZ-3A
construction
Takeoff mass	2,350 kg (at the surcharge)
Instruments
6th
Course of the mission
Start date	October 24, 2007
launch pad	Xichang Cosmodrome
End date	March 1, 2009
Oct 24, 2007 begin Nov 5, 2007 Reaching orbit around the moon Nov 26, 2007 First publication of an image March 1, 2009 Impact on the moon

Chang'e-1 ( Chinese  嫦娥 一號  /  嫦娥 一号 , Pinyin Cháng'é Yīhào ) was the first space probe of the China National Space Administration (CNSA) and the first of several planned missions in the lunar program of the People's Republic of China . The probe was launched on October 24, 2007, reached an orbit around the moon on November 5, 2007, and hit the moon on March 1, 2009. It was used to test technologies for future missions and to study the nature of the lunar surface and the rock. The cost of the probe was put at 169 million US dollars. Another mission followed in 2010 with the lunar orbit Chang'e-2 and in 2013 with a soft landing with Chang'e-3 . In late 2018, Chang'e-4 was launched to study the back of the moon.

The program was named after the moon goddess Chang'e . She appears in a Chinese fairy tale in which a young fairy flies to the moon.

history

The People's Republic of China's lunar program initiated in 1991 by the Chinese Academy of Sciences was initially treated confidentially. It was only on November 22nd, 2000 that the State Council of the People's Republic of China publicly mentioned in its “White Paper on Chinese Space Activities” that China intended to conduct “preliminary studies” for an exploration of the moon. In truth, the scientists had carried out preliminary studies on the geology of the moon since 1992 and in 1998 defined the technological requirements for lunar probes. In 2001, the Chinese Academy for Space Technology , a subsidiary of the China Aerospace Science and Technology Corporation , began an internal feasibility study for an orbiter to explore the lunar surface. The concept was in place in 2003, and after Prime Minister Wen Jiabao released the funds for the first phase of the lunar program on January 24, 2004, the development group was put together at the Academy for Space Technology. By September 2005, the prototype had passed all tests, and by the end of 2005, construction of the real probe was approved. In January 2006, the government of the People's Republic of China officially announced that production of the space probe and its launcher had started, and on July 25, 2006, final assembly of the probe began. In December 2006 the probe was tested in the launch center.

Mission objectives

The People's Republic of China's lunar program serves less for basic research, but rather specifically targets lunar mineral resources. The title of the final report of the Lunar Exploration Project Group at the Chinese Academy of Sciences , presented to the State Council in 2000, was "Scientific Targets of a Probe for the Exploration of Mineral Resources on the Moon by China". Since NASA's Lunar Prospector Mission in 1998/99, people had a pretty good idea of ​​which minerals were to be found in which places on the moon, whereas in China, in addition to iron, people primarily look for the nuclear fuel thorium and that in air - and space travel interested the light metal titanium . Prof. Ouyang Ziyuan, former head of the Institute of Geochemistry of the Chinese Academy of Sciences and one of the most committed advocates of lunar exploration, showed a lunar map made by NASA on May 26, 2003 showing the distribution and metal content of the respective ores. The most important task of the National Space Agency was initially to create its own Chinese maps with the mineral deposits, in addition to collecting information for a safe manned flight to the moon. Therefore, the mission objectives for Chang'e-1 were defined as follows:

• Creation of a three-dimensional map of the lunar surface
• Mapping of the useful elements and substances over the entire lunar surface, both in terms of distribution and content
• Measurement of the thickness of the regolith layer
• Measurement of the solar wind and the high-energy particles ( Solar Energetic Particles ) of solar flares in the space between the earth and the moon

Equipment and payload

The orbiter developed at the Chinese Academy of Space Technology was based on the construction of the communications satellite Dongfang Hong 3 (东方 红 三号), which was launched on May 12, 1997 , not to be confused with the "Technological Test Satellite" sometimes referred to abroad as "Dong Fang Hong 03" 3 “(技术 试验 卫星 三号 or JSSW 3), a reconnaissance satellite launched on July 26, 1975. The China-Brazil Earth Resources Satellite Program already had experience in the search for mineral resources from space. The group around chief designer Ye Peijian basically took the systems of the Ziyuan-1 satellite (资源 一号 卫星, also known as CBERS-1) and the purely Chinese Ziyuan-2 satellite (中国 资源 二号 卫星) and built them into the DFH -3 bus on . The total mass of the probe was then 2,350 kilograms, of which 130 kilograms were accounted for by several devices developed by the National Center for Space Science of the Academy of Sciences using existing, proven technology:

• A stereo camera system for three-dimensional cartography of the lunar surface.
• A laser altimeter to determine the distance between the probe and the surface of the moon in order to be able to create three-dimensional maps for dark areas such as the two poles.
• An imaging spectrometer or interferometer for creating a map of the lunar surface in the visible spectrum.
• A gamma spectrometer for studying the rock composition and radioactive components on the moon, such as for the analysis of 13 metallic elements, whereby the main interest was titanium , plus oxygen and helium-3 .
• An X-ray spectrometer for measuring the distribution of silicon , aluminum and magnesium.
• A microwave radiometer for measuring the temperature of the lunar surface and determining the thickness of the lunar dust.
• A device consisting of three individual measuring devices for measuring the speed, density and temperature of the charged particles of the slow and fast solar wind as well as the protons, electrons and heavy ions that are ejected into space during solar flares. This device began collecting data on the flight from the earth to the moon and then continued the measurements during the orbit in the space near the moon.
• A power supply and data processing device consisting of 5 components, which compressed the data collected by the individual measuring devices, temporarily stored it in a 48 GB memory and, if the probe had visual contact with China, radioed the S-band to the Chinese VLBI network (see below ).
• The piece of music Spring Festival Overture .

Data transmission to earth

The orbit tracking and the reception of the data sent to earth took place with the help of four radio telescopes with diameters between 25 and 50 meters near Shanghai , Ürümqi , Kunming and Miyun near Beijing . The four facilities used are under the control of scientific institutions. In the VLBI observation base Sheshan (佘山 VLBI 观测 基地, Pinyin Shéshān VLBI Guāncè Jīdì ) of the Shanghai Astronomical Observatory in Songjiang , directly at the 25-meter antenna there, the data was also collected and evaluated.

For the launch phase and the entry of the probe into lunar orbit, mission control was additionally supported by ESA's ESTRACK stations in Maspalomas (Spain), Kourou ( French Guiana ) and New Norcia (Australia). The mission showed the need for the expansion of a dedicated Chinese deep space network with a focus on space travel (中国 深 空 测控 网, Pinyin Zhōnggúo Shēnkōng Cèkòngwǎng ).

Mission history

Chang'e-1 was launched on October 24, 2007 at 10:05 UTC with a CZ-3A launcher from the Xichang cosmodrome in China . It entered a 16 hour orbit earth orbit and opened its solar panels. The next day it raised the closest point of its orbit from 200 kilometers to 600 kilometers as planned by briefly igniting its own engines. Within the next seven days, three more orbit transfers took place, during which the probe was transported to an ever higher orbit, and finally with a so-called "earth-moon transfer" the orbit was extended so that the moon could be reached.

After minor orbit correction maneuvers, the probe was able to begin the decisive maneuver on November 5, when it was only 300 kilometers away from the moon, and swivel into a lunar orbit. After two more braking maneuvers, on November 6, Chang'e-1 was in a lunar orbit with an altitude of 213 to 1700 kilometers and an orbital time of three and a half hours. On November 7th, after a third braking maneuver, it reached its final orbit, on which it circled the moon at an altitude of 200 kilometers once in 127 minutes. It was from this orbit that she began her research program as soon as all instruments on board and all four Chinese radio telescopes on earth were ready for use.

On November 26th, the CNSA presented a first image of the moon from the probe to the public. Chinese Prime Minister Wen Jiabao unveiled an image made up of 16 individual photos in the Beijing Space Control Center .

The total lunar eclipse on February 21, 2008 and the partial lunar eclipse on August 16, 2008 posed a certain problem . Normally, on its 127-minute orbit, the probe was only 45 minutes in the shadow of the moon. When on those two days the moon stepped into the shadow cast by the earth into space, the time during which the solar modules did not provide electricity was extended to three hours . The engineers working with Ye Peijian and his deputy Sun Zezhou countered this problem by switching the probe into a kind of sleep mode during lunar eclipses , which reduced the power consumption from the - at that time very cold - accumulators .

On March 1, 2009, Chang'e-1 hit the moon at 09:13 a.m. CET.

Successor Mission

Chang'e-1's replacement probe has been modernized and equipped with a higher resolution CCD camera. The probe was launched under the name Chang'e-2 on October 1, 2010. After it had mapped the surface of the moon from an orbit only 100 km high (half as high as Chang'e-1) by June 9, 2011 , she went to the Lagrange point L _{2 of} the sun-earth system, where she stayed for about ten months and measured the solar wind . After a flyby of the near-Earth asteroid (4179) Toutatis on December 13, 2012, Chang'e-2 was sent on an elongated elliptical orbit into interplanetary space. After reaching the apogee of its orbit 300 million kilometers away, the probe is expected to return to 7 million kilometers in 2029.

See also

• List of space probes
• Chronology of the moon missions
• Lunar program of the People's Republic of China
• Space of the People's Republic of China
• List of man-made objects on the moon

literature

• Chang'e-1. In: Bernd Leitenberger: With space probes to the planetary spaces: New beginning until today 1993 to 2018 , Edition Raumfahrt kompakt, Norderstedt 2018, ISBN 978-3-74606-544-1 , pp. 264–269

Web links

Commons : Chang'e-1  - collection of images, videos and audio files

• Bernd Leitenberger: Chang'e-1
• Xinhua: "First unmanned lunar mission set for 2007" (August 16, 2005, English)
• Chang'e in the Encyclopedia Astronautica (English)
• Mission overview to Chang'e 1 at NASA (English)
• Ziyuan Ouyang et al: The Scientific Objectives of Chinese Lunar Exploration Project. (English; PDF; 133 kB)

Individual evidence

1. ^ Liu Dan: China to launch moon probe next April. In: chinadaily.com.cn. May 17, 2006, accessed December 30, 2018 . 
2. ^ Information Office of the State Council: China's Space Activities, a White Paper. In: spaceref.com. November 22, 2000, accessed December 13, 2019 . 
3. ↑ 孙泽洲 从 “探 月” 到 “探 火” 一步 一个 脚印. In: cast.cn. October 26, 2016, Retrieved December 12, 2019 (Chinese). 
4. ↑ 钱 钰: “嫦娥” 总 师 孙泽洲 受聘 母校 南航 大. In: news.carnoc.com. March 6, 2014, accessed December 13, 2019 (Chinese). 
5. ↑ Mo Hong'e: China tests its 1st lunar probe: space official. In: gov.cn. July 25, 2006, accessed December 30, 2018 . 
6. ↑ 中国 嫦娥 工程 的 “大 三步” 和 “小 三步”. In: chinanews.com. December 1, 2013, accessed April 26, 2019 (Chinese). 
7. ^ Former Directors. In: gyig.cas.cn. Retrieved April 26, 2019 . 
8. ↑ 欧阳自远: 飞向 月球. In: cctv.com. May 26, 2003, Retrieved April 26, 2019 (Chinese). 
9. ↑ Mark Wade; China in Encyclopedia Astronautica , accessed May 8, 2019.
10. ↑ Mark Wade: JSSW in the Encyclopedia Astronautica , accessed on May 8, 2019 (English).
11. ↑ 东方 红 3 号 卫星 平台. In: cast.cn. July 31, 2015, accessed May 9, 2019 (Chinese). 
12. ↑ 徐 超 、 黄治茂: “嫦娥 一号” 副 总设计师 孙泽洲. In: news.163.com. November 8, 2007, Retrieved May 9, 2019 (Chinese).  The engineers in the left margin, all employees of CAST, are the group leaders for the development of the individual systems of the probe itself (control, telemetry, antenna, etc.). The scientific payloads were developed by the National Center for Space Science of the Chinese Academy of Sciences.
13. ↑ 孙泽洲 从 “探 月” 到 “探 火” 一步 一个 脚印. In: cast.cn. October 26, 2016, Retrieved May 6, 2019 (Chinese). 
14. ↑ Mark Wade: Phoenix Eye in the Encyclopedia Astronautica , accessed on May 9, 2019.
15. ↑ Mark Wade: ZY in the Encyclopedia Astronautica , accessed on May 9, 2019.
16. ↑ Chinese scientists to focus four tasks in moon exploration ( Memento of 5 November 2007 at the Internet Archive ) XINHUA online, July 21, 2006. With this gamma spectrometers were actually taken the individual elements, so pure Ti, not titanium dioxide or rutile or ilmenite .
17. ↑ 探 月 工程. In: nssc.cas.cn. Retrieved April 25, 2019 (Chinese). 
18. ↑ China tests super telescopes for moon-probe project. People's Daily online, June 20, 2006
19. ↑ Han Lin: Shanghai Lands Star Role In Satellite Mission. In: spacedaily.com. June 14, 2006, Retrieved April 27, 2019 (Chinese). 
20. ↑ ESA tracking support essential to Chinese mission ESA News, October 26, 2007
21. ↑ 嫦娥 一号 所 拍 中国 首 幅 月球 全 图 发布. In: mil.news.sina.com.cn. November 12, 2008, Retrieved May 1, 2019 (Chinese). 
22. ↑ 董光亮 et al .: 中国 深 空 测控 系统 建设 与 技术 发展. In: jdse.bit.edu.cn. Retrieved May 4, 2019 (Chinese). 
23. ↑ China presents first images of the moon orbiter Chang'e-1 heise online, November 26, 2007
24. ↑ 李艳: 从 地球 到 月亮 —— 嫦娥 一号 3 年 跨越 之 路. In: scitech.people.com.cn. November 6, 2007, accessed December 13, 2019 (Chinese). 
25. ↑ Günther Glatzel: Chang`e 2: From the moon satellite to the space probe. raumfahrer.net, June 10, 2011, accessed on December 13, 2019 . 
26. ↑ 田 兆 运 、 祁登峰: 嫦娥 二号 创造 中国 深 空 探测 7000 万 公里 最 远距离 纪录. In: http://news.ifeng.com . February 14, 2014, accessed December 13, 2019 (Chinese).