Backgrounder: Chinas triple jump progress in lunarprobes

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China pursues "zero window" launch for lunar probe(Xinhua) 19:26, November 29, 2013Email|Print|Comments

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BEIJING, Nov. 29 -- China will strive to launch its Chang"e-3 lunar probe at the optimaltime within the launch window, the Xichang Satellite Launch Center said on Friday.China is scheduled to launch the probe in early December. It will be the first time for aChinese spacecraft to soft-land on the surface of an extraterrestrial body.The center said it will pursue a "zero window" launch for the mission, referring to a launchat a pre-determined optimal time for the probe to reach its intended target. If a "zerowindow" launch is not achieved on time, it must be delayed until the next launch window.If a zero window launch is achieved, Chang"e-3 will not need to make trajectory correctionbefore entering the pre-selected orbit, and fuel can be saved during orbital transfer,according to the center.The zero window launch can be achieved through timing control of the rocket ignition, saidZhao Ming, deputy commander in charge of China"s lunar program launching site system.However, the launch will be influenced by a variety of factors, including the project"stargets, the motion of the earth, moon, and sun, as well as the weather conditions at thelaunch site, Zhao added."Achieving a zero window launch is difficult, and success will reflect the ability for theproject"s different systems to coordinate and cooperate," Zhao said.（Editor：YanMeng、Chen Lidan）Related readingUnknown surface conditions will impact the Chang"e-3 missionMicro-motors key to lunar probe"s successChina will achieve first soft landing on the moonChina readies moon rover missionData processing and analysis vital for launching moon rover missionThe name "Yutu" was proposed by domestic, overseas compatriotsBackgrounder: Timeline of China"s lunar programChina"s lunar probe to land on moon next monthChina to launch Chang"e-3 lunar probe in early Dec.We Recommend

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Finland--anytime you want is right time to go: AmbassadorName:Backgrounder: China"s "triple jump" progress in lunarprobes(Xinhua) 19:29, November 29, 2013Email|Print|Comments

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BEIJING, Nov. 29 -- The upcoming Chang"e-3 mission will carry the first Chinesespacecraft to soft-land on and explore an extraterrestrial object.The Chang"e-1 to Chang"e-3 missions have made a "triple jump" between 2007 and 2013.Chang"e-1: starting from nothingBlasting off at 6:05 p.m. on Oct. 24, 2007 from southwest China"s Xichang Satellite LaunchCenter, Chang"e-1 entered lunar orbit after 18 days with only one orbital trimming -- theadjustment required to achieve the desired orbit around an object.On Nov. 12, 2008, a hologram of the whole moon made with data collected by Chang"e-1was published. It remains the most complete lunar hologram published to date.At 4:13 p.m. on March 1, 2009, Chang"e-1 hard-landed on the lunar surface.Chang"e-1 opened up a new age of deep space exploration for China.Chang"e-2: achieving several world firstsChang"e-2, a pilot probe for Stage II of the lunar program, was launched on Oct. 1, 2010from Xichang, the site from which Chang"e-3 will also be launched in a few days" time.One of Chang"e-2"s tasks was to verify key technology ahead of the soft-landing. UnlikeChang"e-1, Chang"e-2 was sent directly into lunar orbit by a Long March-3C carrier rocket.The transfer from the Earth"s orbit to that of the moon was attained in only 112 hours.On arrival in a circular orbit 100 km over the lunar surface, the spacecraft transitioned to acloser elliptical orbit after finishing in-orbit tests and took a series of 1.5-meter resolution(meaning each pixel captures a 1.5-square-meter area of land) pictures of the moon"s SinusIridium landmark, the chosen landing site of Chang"e-3.Wu Zhijian, spokesperson for the State Administration of Science, Technology andIndustry for National Defense, said Chang"e-2 achieved several firsts. It was the first timea spacecraft had flown from lunar orbit to the second Lagrange Point (L2) orbit, where thegravity of the sun and Earth balance the orbital motion of the satellite; and the first time aspacecraft encountered the Toutatis asteroid at close range, capturing images with aresolution of 10 meters.At present, Chang"e-2 is 60 million km from Earth and has become China"s first man-madeasteroid in the solar system. It continues to fly into deeper space and is expected to go asfar as 300 million km from Earth before contact is lost.Chang"e-3: Soft-landing on an extraterrestrial objectSo far, only the United States and the former Soviet Union have soft-landed on the moon.If successful, China will become the third country to do so.After entering lunar orbit, Chang"e-3 will go through six stages of deceleration to descendfrom 15 km above to the lunar surface.The soft-landing processes of the U.S. and former Soviet Union"s unmanned spacecraft hadno capacity to hover or avoid obstacles. Chang"e-3, on the other hand, can accuratelysurvey landforms at the landing site and identify the safest spots on which to land.In order to land quickly, the probe is equipped with high-precision, fast-response sensorsto analyze its motion and surroundings. The variable thrust engine (completely designedand made by Chinese scientists) can generate up to 7,500 newtons of thrust.Yutu (Jade Rabbit), the autonomous moon rover which will detach from the lander, will becontrolled when necessary by scientists on Earth.（Editor：YanMeng、Chen Lidan）Related readingChina pursues "zero window" launch for lunar probeChina to launch lunar probe for landing missionChinese space program: Core of probe to deep space is resourceChina"s next target: Solar probeNation to conduct 16 space launches in 2013China to launch its Shenzhou 10 spacecraft next yearMassive radio telescope to assist China"s moon missionsChina considers more Mars probes before 2030China will send first rover to moon in 2013China to launch moon-landing orbiter in 2013We Recommend