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| previous_mission = Chang'e 1 | next_mission = Chang'e 3 | programme = Chinese Lunar Exploration Program }} Chang'e 2 (; ) is a Chinese unmanned lunar probe that was launched on 1 October 2010.〔 It was a follow-up to the Chang'e 1 lunar probe, which was launched in 2007. Chang'e 2 was part of the first phase of the Chinese Lunar Exploration Program, and conducted research from a 100-kilometer-high lunar orbit in preparation for the December 2013 soft landing by the Chang'e 3 lander and rover. Chang'e 2 was similar in design to Chang'e 1, although it featured some technical improvements, including a more advanced onboard camera. Like its predecessor, the probe was named after Chang'e, an ancient Chinese moon goddess. After completing its primary objective, the probe left lunar orbit for the Earth–Sun L2 Lagrangian point, to test the Chinese tracking and control network, making the China National Space Administration the third space agency after NASA and ESA to have visited this point.〔SpaceDaily. ("China's second moon orbiter Chang'e-2 goes to outer space" ). XNA. 10 June 2011.〕 It entered orbit around L2 on 25 August 2011, and began transmitting data from its new position in September 2011.〔("Chinese space craft travels 1.7 mn km deep into space" ). ''India Times''. 21 September 2011. Retrieved 17 October 2011.〕〔("Chang'e 2 reaches liberation point 2" ). Xinhua. 27 August 2011. Retrieved 21 November 2011.〕 In April 2012, Chang'e 2 departed L2 to begin an extended mission to the asteroid 4179 Toutatis,〔 which it successfully flew by in December 2012. This success made China's CNSA the fourth space agency to directly explore asteroids, after NASA, Europe's ESA and Japan's JAXA. As of 2014, Chang'e 2 has travelled over 100 million kilometres from Earth, and is conducting a long-term mission to verify China's deep-space tracking and control systems.〔 ==Design== Chang'e 2 was broadly similar to the Chang'e 1 probe, but had important differences. While Chang'e 1 operated in a 200-kilometer orbit, Chang'e 2 flew at only 100 kilometers, allowing for higher-resolution images and more precise science data. The probe also possessed a higher-resolution camera, able to resolve features as small as across from orbit. According to Qian Huang of the Shanghai Astronomical Observatory and Yong-Chun Zheng of the NAOC,〔("China to launch Chang'e 2 on Friday, October 1" ). Planetary.org. 28 September 2010. Retrieved 20 November 2011.〕 the spacecraft also had a shorter Earth-to-Moon cruise time of 5 days, rather than 12. The probe's launch rocket had two more boosters to accomplish this more direct route to the Moon. Furthermore, its laser altimeter's footprint was smaller than Chang'e 1's, achieving 5-meter vertical accuracy in its estimate of the Moon's radius. It also pulsed more frequently – five times per second rather than just once per second, as Chang'e 1's altimeter did. Additionally, the probe's main camera had a spatial resolution of , rather than . The total cost of the Chang'e 2 mission was approximately CN¥900 million (). Late in the mission, Chang'e 2's orbit was lowered to an elliptical one, with the same apolune (100 kilometers) as Chang'e 1, but with a perilune of only 15 kilometers. Tracking for the mission was performed with an X-band radio capability, which was not available for Chang'e 1. Zheng remarked that "the mission goals of CE-2 were focused into the high resolution image for the future landing site of CE-3 lunar lander and rover. The key technology about soft landing on the Moon will be tested in the CE-2 mission. The success of CE-2 will provide an important technical basis for the successful implementation of China's future lunar exploration."〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Chang'e 2」の詳細全文を読む スポンサード リンク
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