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The author:(作者)hpmailerpublished in(发表于) 2013/12/1 20:43:29 Moon rocket in place， third， 3 times higher than the second into orbit accuracy
Authorities wide nets of Xichang, December 1 (Xinhua Zhang Mian Mian Li Qixuan) aspect ratio, according to voice of the news reports, Chang e, third in China lunar probe launch tomorrow 1:30. At present, the long third b rocket carrying Chang, third, already second tower at the Xichang satellite launch Center in place, ready to.
Chang, first select the long third hepatitis a rocket for its escort, when Chang, second mate into long third c rocket, this time to become immortal, the third, the other half is a long third-b rocket. Why long favored by Chang, third, Chang has lifted the lunar module's ladder? It Tower "third," what has been done to improve it? Reporters combed through for everyone in this launch highlights and highlights:
The first point is high capacity requirements
Rocket models described Jiang Jie, Chief Architect, Chang e, third the weight reached 3,700 kg, over more than 1000 kilograms heavier than Chang, second, so choose a takeoff weight of about 456 tons, China's launch up to three of the most powerful high-orbit satellites:
Jiang Jie: the long third, b is the long third, a core level, comes bundled with four boosters, based on a standard geostationary transfer orbit that measures its capacity, long March b rockets, third is 5.5 tonnes.
Point two: Rails require high precision
As gold rockets, launch success rate was also up to three have been identified as "Moon ladder" important reasons. In the past three years, long March rockets have carried out the third series 26 times, twice successfully, the success rate has reached 100%. At the same time, Chang, third moon mission requirements for accuracy is higher, "from Paris to Shanghai by playing golf hole in one" describes the precision of the moon. Rocket Commander Cen Zheng, accuracy 3 times higher than Chang, second rocket into orbit more than doubled, increased reliability from 0.938 to 0.942, reaching top form:
Cen Zheng: the launching site began, our equivalent of a relay race first, take the detector to the earth-moon transfer orbit, target is the moon. Rocket ourselves some new applications or hardware, software upgrades, the rocket is one of the representatives, product is a sieve and sieve, in the case of an existing pick of the best.
The third point: the launch window for high
To ensure that the tower ", third" moon landing perfectly, this task was first introduced many Windows, narrow width and high-precision orbit launches. Launch window selection is mainly based on the Earth, the Sun, the Moon, the three law of motion of celestial bodies, as well as factors such as weather, the probe orbits of the launch site. After launch site area command decided to become immortal, the third issue of the timing of the launch on December 2 have been identified.
Cen Zheng, said Chang, third has prepared a total of six launch window, two a day. The first launch window width is 4 minutes, if you miss the first launch window, enter the second launch window, the second launch window width of only 1 minute:
Cen Zheng: I have this 3-day orbital rocket flight time is not the same as, rocket flight is more than 1100 seconds with the shortest, the longest possible is more than 1400 seconds. First window not go, so we're going to the first day of the second window, would also turn against the process and then go back, we have a normal process.
Point four: high adaptive capacity requirements
Said Jiang Jie, Chief Designer of the launch vehicle system, multiple Windows, narrow the width of the emission is difficult. Six implies a need to calculate in advance the launch window, the design of the six Lunar trajectories, each track must be ready to go all out:
Jiang Jie: rocket launch opportunities to achieve the six-State, we have to prepare it, either State can achieve emission at any time. For different tracks and different equipment as well as software used in Windows, we do a full validation.
In measuring, measurement and control, communication and meteorological satellites, five systems in close coordination with, generally, must first be aimed at launch snagged the first window to launch. Rocket Commander Cen Zheng said, took off from the fire starting, about 20 minutes later, the rocket and moon third, separation, rockets to as Chang-the lunar module ladder task completed, Chang, third entered the earth-moon transfer orbit will continue to explore the journey of the Moon:
Cen Zheng: the rocket sent the probe into the earth-moon transfer orbit, it has one argument a perigee of 200 kilometers and apogee of 380,000 kilometers of highly elliptic orbits, and finally separated properly, it will be successfully completed.
(Original title: Chang, third ready for Rails 3 times times more precision than Chang, second)
央广网西昌12月1日消息(记者张棉棉 李其轩)据中国之声《新闻纵横》报道，我国嫦娥三号月球探测器即将于明天凌晨1：30分发射。目前，搭载嫦娥三号的长征三号乙运载火箭，已经在西昌卫星发射中心二号塔架就位，整装待发。
嫦娥一号选择了长征三号甲型运载火箭为它保驾护航，嫦娥二号时的伴侣变成了长征三号丙型运载火箭，这一次，嫦娥三号的另一半是长征三号乙型运载火箭。为什么长三乙会受到嫦娥三号的青睐，成为托举嫦娥登月的天梯？它又为“嫦娥三号”做了哪些改进？记者为大家梳理了本次发射中的看点与亮点：
看点一：运载能力要求高
火箭型号总设计师姜杰介绍，嫦娥三号的重量达到了3700公斤，比嫦娥二号重1000多公斤，所以选择了起飞质量约为456吨、我国发射高轨道卫星能力最强的长三乙：
姜杰：长征三号乙是以长征三号甲为芯级，捆绑了四枚助推器，按照标准的地球同步转移轨道衡量它的运载能力的话，长征三号乙火箭是5.5吨。
看点二：入轨精度要求高
作为我国的金牌火箭，发射成功率高也是长三乙被确定为“嫦娥天梯”的重要原因。在过去的三年间，长征三号系列火箭共进行了26次发射，次次成功，成功率达到了100%。同时，嫦娥三号的落月任务对精度的要求更高，有人曾用“从巴黎打高尔夫球到上海入洞”形容落月的精准。火箭总指挥岑拯表示，火箭入轨精度比嫦娥二号高3倍多，可靠性从0.938提高到0.942，达到最好的状态：
岑拯：进入发射场开始，我们相当于接力赛的第一棒，把探测器送到地月转移轨道，目标点是月球。火箭我们本身有些新的应用或者硬件、软件的升级，这枚火箭就是其中的代表，产品是筛了又筛，在现有的情况下挑的最好的。
看点三：发射窗口要求高
为确保“嫦娥三号”能够完美登月，此次任务首次采用多窗口、窄宽度和高精度入轨发射。发射窗口的选择主要基于地球、太阳、月球三个天体的运动规律，以及发射场天气、探测器轨道等因素。经发射场区指挥部决定，嫦娥三号的发射时间已经确定为12月2日1点30分。
岑拯表示，嫦娥三号共准备了六个发射窗口，每天有两个。第一发射窗口宽度为4分钟，如果错过第一发射窗口，则进入第二发射窗口，第二发射窗口宽度仅为1分钟：
岑拯：我这3天6个轨道的火箭飞行的时间是不一样的，火箭飞行的时间最短的是1100多秒，最长的可能是1400多秒。比如说第一窗口没打出去，那么我们要第一天的第二个窗口，还得要重新再反流程再走回来，我们一个正常的流程。
看点四：适应能力要求高
运载火箭系统总设计师姜杰介绍说，多窗口、窄宽度的发射很难。六个发射窗口意味着需要提前计算、设计出六条奔月轨道，每条轨道都要做好准备，全力以赴：
姜杰：火箭要实现发射机会六种状态，我们都要把它做好准备，随时任何一种状态都可以实现发射。针对不同轨道的、不同窗口的所用的设备还有用的软件，我们都做了充分的验证。
在发射场测发、测控、通信、气象、勤保五大系统密切协同下，一般而言，发射时肯定首先将瞄准第一窗口择机发射。火箭总指挥岑拯说，从点火起飞起计算，约20分钟后，火箭就会和嫦娥三号分离，火箭作为嫦娥登月天梯的任务就此完成，进入地月转移轨道的嫦娥三号将继续前往月球的探索旅程：
岑拯：火箭把探测器送到地月转移轨道，它有一个参数近地点200公里，远地点在38万公里的大椭圆的轨道，而且最后分离正常，这才算是圆满的完成。
(原标题：嫦娥三号整装待发 入轨精度比嫦娥二号高3倍)
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