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The author:(作者)aaapublished in(发表于) 2013/12/6 12:19:52 Chang-third tonight is expected to enter lunar orbit 100 km-Chang， third-detector
Morning News (reporter Hana) Beijing morning news reporters learned from the defense industry, as of December 5, Chang the third probe, have been running at about 88 hours, flying nearly 350,000 km in good working order. It is understood that Chang is scheduled for this evening, are captured in the Moon, third "brake", entered lunar orbit 100 km.
On December 3, the Beijing Aerospace command and control center successfully completed a second mid-course corrections, and accurate calibration 7,500 n engines were used for the first time, that is, functional test, as this engine will play a large role in the fall months. 7,500 cattle used this engine is the first variable thrust engine, developed by China Aerospace Science and Technology Corporation is responsible for, lift can be achieved from 1500 up to 7,500 cattle a large range of continuously changing, with high performance, adaptability, combustion stability, simple structure, low cost and other striking features, it's Chang, third brake, power down the main power probes in recent months.
"The moon lady, third" probe to achieve the surface safe and soft landing, conventional rocket engine and propulsion system to complete this task. Because, in such a celestial body surface of the atmosphere of the moon landing maneuver, conventional engines thrust of change cannot be achieved. Only a variable thrust engine to meet the complete lunar landers in mid-course corrections, in recent months, brake, power down, hovering over a soft landing missions. It can be said that in the course of this remarkable moon to become immortal, could end up third, stabilized and ended up, 7,500 n variable thrust engine in charge.
In view of launching Chang third long third b probe rocket into orbit with higher accuracy to become immortal, the third probe, the first two mid-course corrections are also very accurate, you can meet the requirements of braking and subsequent orbit control in recent months, and to become immortal, the third spacecraft flight control programme has a good adaptability, are no longer conducted for mid-course corrections.
According to the plan, Chang the third spacecraft in orbit after launch flight for about 5 days, braking in recent months were Lunar capture, entered lunar orbit 100 km. Goddess Lunar trajectories are similar to Chang e, second, third, and Chang shortens the first 7 days. Flying about 4 days later, orbit entered 15 km away from the elliptical orbit; fly again about 4 days later, from a height of about 15 km point power dropped in recent months. After landing probe that snagged release Rovers, the lander in position detection, Lunar Rover patrol reconnaissance.
晨报讯(记者 韩娜) 北京晨报记者从国防科技工业局获悉，截至12月5日18时，嫦娥三号探测器已正常运行约88小时，飞行近35万公里，工作状态良好。据了解，嫦娥三号预计于今天傍晚被月球捕获“刹车”，进入100公里的环月圆轨道。
12月3日，北京航天飞行控制中心顺利完成第二次中途修正，并对首次使用的7500牛发动机进行了精准标定，也就是功能的测试，因为这台发动机将在落月中发挥大作用。此次使用的7500牛发动机是我国首台变推力发动机，由中国航天科技集团公司负责研制，可实现推力从1500牛到7500牛大范围的连续变化，具有性能高、适应性强、燃烧稳定，结构简单、成本低廉等显著特点，它是嫦娥三号探测器近月制动、动力下降的主用动力。
“嫦娥三号”探测器要实现月面安全软着陆，传统火箭发动机和推进系统，无法完成这一任务。因为，在月球这一无大气天体表面的软着陆机动飞行中，传统发动机无法实现推力的变化。只有变推力发动机，才能满足完成月球着陆探测器中途修正、近月制动、动力下降、悬停段等软着陆任务。可以说，在此次举世瞩目的落月过程中，嫦娥三号能否落得稳，落得准，7500牛变推力发动机说了算。
鉴于发射嫦娥三号探测器的长征三号乙运载火箭入轨精度较高，嫦娥三号探测器的前两次中途修正也非常精准，可以满足近月制动和后续轨道控制的要求，同时，嫦娥三号探测器飞行控制方案具有较好的适应性，不再进行第三次中途修正。
按照规划，嫦娥三号探测器发射后在轨飞行约5天，近月制动被月球捕获，进入100公里的环月圆轨道。嫦娥三号奔月轨道与嫦娥二号类似，比嫦娥一号缩短了7天。飞行约4天后，变轨进入15公里×100公里的椭圆轨道；再飞行约4天后，从高度约15公里的近月点开始动力下降。着陆后，探测器择机释放月球车，着陆器开展就位探测，月球车开展巡视勘察。
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