Go homepage(回首页) Upload pictures (上传图片) Write articles (发文字帖)
The author:(作者)aaapublished in(发表于) 2013/12/16 0:34:31 Countries have been 129 probe to the Moon， the success rate is only 51%，
Morning news reporter Yang Yucai
"The Moon" is about to usher in the most wonderful touching moment. According to "the Moon" schedule to become immortal, the third will be held on December 14, Rainbow Bay, landing on the lunar surface, and began a 3-month lunar surface inspection survey.
Chang, third encounter hostile environment on the Moon? It will depend on what the Moon sustain "life"? "YUTU" How will the Moon Lunar Rover patrol work? Pictures, information and other information collected is passed back to 380,000 miles of "mother" Earth? Recently, the morning news reporter interviewed the eighth Research Institute of the China Aerospace Science and technology group 804, 805, 811, a number of experts, representing the Shanghai aerospace power, participated in the development of Chang-third moon.
Question 1: how the lunar surface environment of?
"The rabbit" to bear "the Moon" over more than 300 degree Celsius temperature difference 1/6g gravity environment
The legendary "Moon Palace" absolutely wonderful to become immortal, rabbit in the Moon and dance. But in the real Moon, no air, no water, only as high as more than 300 degree Celsius temperature difference.
The morning of December 2, Chang e, third take a long third away 23 rocket from the Xichang satellite launch Center began its journey to the moon. After the launch phase, earth-moon transfer period, after a lunar and a drop in power to become immortal, the third will be a soft landing on the lunar surface.
In a morning news reporter interview, Research Institute of China Aerospace Science and technology group of the eighth No. 805, the experts say, temperature is the moon facing Chang, third after the first test. Rover wheels, rocker working parts are metallic materials with thermal expansion and contraction characteristics, high demands on material and machining precision. If expansion excess, sideng moving parts prone to card failure.
In addition to outside temperature, gravity on the Moon 1/6g, is also a major challenge. Designers said the lunar surface soil is very loose and rugged, even the steep slope. In the context of such gravity, Moon visited not only want to keep the car stable, would also like to have better sex, less side.
Eighth Academy of surface topography of integrated simulation test in the control room, researchers conducted on simulated Lunar soil test; 1/6g gravity followed by hanging to achieve, only one-sixth the weight of the car in the simulation of the moon on the lunar surface.
In addition, the surface Lunar soil will form a suspension of small particles, and because the Lunar soil with static electricity, easily absorbed in the moon on the wheels of the vehicle, the seal car parts the moon came out with a very high demand. "If these particles or dust into the bearing, light will increase the friction, then stuck bearing, affect the Lunar Rover mobility. ”
Question 2: "the rabbit" station "off"?
"The ladder," get off on its own procedures, no small risk
The whole "rabbit" Rovers controlled by mobile, navigation, structure and institutions, integrated electronics, power, thermal control, measuring, data transmission, and all 8 of the payload system.
Research Institute of China Aerospace Science and technology group of the eighth move system for visiting designers, said: "this system includes 6 wheels, rocker and differential mechanism, like the car's chassis. "It is with this mobile system," the rabbit "to step off the lander, surface forward, backward, using the Steering, steering, can still climb a 20 degree ramp, over 20 cm tall obstacles.
"The lander release Rovers, is one of the more difficult. "The Shanghai aerospace experts said Hu Zhenyu, from launch to Lunar Lander, Rover is fixed at the top of the lander. When the lander after landing, transfer agencies airsteps unlock, then Rover and Lander connection partially unlocked, solar panels and move to the top hanging ladder, finally, hanging ladder with Rover down shifted, until the front hanging ladder touched the lunar surface, fell along a ladder of Lunar Rover onto the Moon's surface.
"Say this step is tricky, because the Moon is moving along the hanging ladder in the course of a number of uncontrollable risk. "Although the Lander will select a smooth place to land as much as possible, but coming out of the stance of the ladder are more difficult to control, is likely to tilt. Lunar Rover in the downturn, conducted entirely on its own established procedures, speed is very slow, but its direction and speed are not affected by ground control.
"Judging from international data, countries around the world in the Moon exploration carried out 129 times, the success rate is 51%. From these figures, the lunar exploration activities risk is still very large. "On November 26, Chang-third mission held its first news conference, Li Benzheng, said Vice Director of lunar exploration program, Rovers and landers falls on the moon when Rover descended out of the lander, is a difficult process, it is also very important to highlight.
To ensure the Rover can safely drop to the surface of the Moon, visited the mobile system of ground hundreds of times, the researchers test to simulate a verify that the release process under a variety of gestures. Benjamin l. Liebman is press release said, although doing a lot of simulation, but awareness of the Moon is still incomplete and inadequate, so there is a certain risk, also plans to do to perform the task.
Question 3: "the rabbit" Moon how to relax?
Day and night for up to 14 days, only the months of daylight, so that "the rabbit" 3-month mandate will be "half asleep, half awake"
When Rover leaves the lander, set foot on the lunar surface, enters the lunar phases. According to Li Benzheng introduction to become immortal, each on the third issue of the lander and the Rover is equipped with 4 types of payloads, to survey the Moon, month table.
Rovers in the months table how to work? Designers said, moving over short distances, capable of autonomous navigation for Lunar Rover; but long distance, large range of visits, you need to set the route. "The Rover made a move for a short period would give a feedback on the ground, including pictures or data, the ground forms a path planning based on this feedback, through directive commanding Rovers forward, backward, or turn. ”
Under the Moon exploration plan to become immortal, the third for a 3-month probe on the moon. But because of the months of daylight and Moonlight because (one day and night on the Moon amounted to 28 days on Earth, a night is equivalent to 14 days on Earth), "rabbit" Rovers only month daylight hours at work, Yamashita is dormant.
3 months of inspections on the lunar surface, "the rabbit" will rely on the advanced equipment, the Moon's surface for three dimensional optical imaging, infrared spectroscopy, scientific exploration of the lunar regolith layer thickness and structure, the deepest allows you to explore the depths of 100 metres under the surface, the Moon's surface material analysis of the main elements of the scene. Data radioed back that will help people more directly and more accurate understanding of the mysteries of the moon.
Question 4: how to "sleep" and "wake up"?
By means of ground control staff instructions, "the rabbit" in "sunset" solar panels when gathering, prevent loss of body temperature goes into hibernation, "Sunrise" electricity supply, sleep, awake wake module
When in an interview with morning news reporter, bear the goddess the third power subsystem No. 811, Deputy Director of the China Aerospace Science and technology group introduced Qian Bin to become immortal, the third moon power subsystem, by solar panels, a set of lithium-ion batteries, sleep, awake module and power supply controller. When Landers after achieving a soft landing on the lunar surface, followed by a lander to the moon to charge their cars, to initialize the Lunar Rover. "Solar array is like a power plant, power controllers are used to manage power plants produce electricity, in addition to providing for Landers and Rovers use, are to be used for lithium-ion batteries. "Qian Bin said, due to the Moon for up to 14 days, even with lithium-ion batteries can not meet the needs of Lunar Rover 14 days in a row, it can only rest. By design, when the Sun's rays and the lunar month when the angle between the plane of less than 5 degrees, the ground control officer will issue a directive, solar panels to gather on one side of the Moon, wrap the outside of the Rovers box to prevent the loss of body temperature by radiation in the moonlight. Adjust the angle of the panels are on the other side, at the direction of sunrise. "After the Rovers into hibernation, power will be turned off to save power. ”
Qian Bin said, moonlit night for 14 days after the end of month day began. When the Sun rose to the surface at 5 degrees, extend the solar panels started to supply, sleep, awake module will wake up Rover, get back to work. "It can be said that Rovers ' sunset and rest ', is controlled from the ground; ' sunrise ', we've got Rovers to awake. ”
According to mission planning, Rovers will be the tasks carried out in the months table for a period of 3 months. "Our spacecraft design life is generally far higher than the mandate, although only three months of the mandate period, but Rovers will also continue to work after three months. "Qian Bin said, there are two main factors that affect the spacecraft life, above all, energy system, regardless of nickel-cadmium batteries, lithium-ion battery or the solar cells, will decay over time, followed by the mechanical parts of a spacecraft, progressively lengthened over time, such as aging or failure.
Question 5: how the Moon "stay warm"?
"Rabbit" had embraced nuclear energy "warm baby" and, moreover, its wrapped in a layer of Golden "coats" resist temperature differences "magic weapon"
In addition to sleep, awake module, to become immortal, the third, another major highlight is that it carries an isotope heat source. This is the first time China's spacecraft uses of nuclear energy. "At present, the main plutonium-238, it radiates in the decay process of high-energy particles can provide heat for thermal material, cabin temperature stays above freezing $literal of the device. "Qian Bin told reporters that Chang carried by third isotope, is only used as a source of heat, Chang, fourth on the future or to install radioisotope thermoelectric power, carried by using isotopes to combined heat and power generation.
The plutonium-238 isotope's half-life is very long, for more than 80 years, so is the most ideal energy interplanetary probes. "The interstellar probe, farther away from the Sun, the Sun less, solar cells cannot work effectively when you needed to use radioisotope thermoelectric power. ”
United States "traveller", "curiosity" Mars probe, plutonium-238 isotope thermoelectric power as heat energy. Qian Bin said, the "Traveler" probe launched 36 years have passed since, but it carries the isotope thermoelectric power output attenuation of less than 40% only. "The plutonium-238 isotope, because this isotope half-bust cycle long enough, and the fission products into larger particles, penetrating is relatively weak, security was heightened. ”
Moon car-the gold-wrapped "coats", but also "the rabbit" resist temperature differences "magic weapons". Reflects the strong sunlight in the daytime, reduced body temperature; body heat at night to prevent the car causes hypothermia.
Question 6: how to "mother 's" contact?
Deep space "broadband wireless" backhaul data, average speed of around 1M per second transmitted back to Earth
"If you compared the Chang, third is a kite flying to the Moon, measuring and controlling data transmission system is the kite. "Eighth Academy of a professional technology Institute of the China Aerospace Science and Technology Group Chief Designer, told reporters. Chang, third visit the bear (the Rover) measurement data transmission system. "Through this invisible ' kite ', the ground work orders reach the Moon; collected in a survey of Lunar Rover data, pictures and this ' line ' return to Earth. ”
According to the introduction, through the many pairs of points system, Rover collected data, in accordance with the average at around 1M per second transmitted back to Earth. 380,000 kilometers of distance, is already very fast "wireless broadband".
To achieve such speeds, Rover antennas must have a large enough volume and radiometric performance. The researchers propose a creative programme of the Institute, the antenna as the Rover's mast, which can send and receive signals, can also support panorama camera. "There are many advantages of this new programme. First, directed antenna and Panorama camera does not mutual interference, directed antenna achieved has hemisphere space no block high gain radiation performance, can to ground transmission large data, and Panorama camera also obtained has full depending on field Imaging no block; also, antenna and mast combined Hou, can full uses Moon car limited of space, and antenna bracket used carbon fiber material, also can reduced Moon car of weight. "The designer said.
The antenna mast, solved the problem of transmitting power and bulk transfer, but another problem with the attendant. "Rovers facing environment, bad lot than the environment of Earth-orbiting satellites. "He said that satellites in orbit around the Earth in a circle is about 2 hours, and some were less than 2 hours, that is satellite Sun and shade did not live very long, environmental temperature experienced by the satellite will be small. But lunar months of daylight and Moonlight night, alternating day and night only once for 14 days, which resulted in about 300 degrees Celsius temperature difference. "Antenna needed throughout the work, and cannot be loaded into the ' incubators ', can only be installed on Rover outside, exposed to the surface of the moon. It must be able to withstand up to 150 degrees Celsius, the lowest temperature lingxia180sheshidu test. ”
To this end, researchers made a lot of difficult ground validation tests, such as thermal vacuum testing and liquid helium environment of low temperature storage test, full validation of the antenna's ability to adapt to circumstances in a huge temperature differences on the surface of the moon.
(Original title: the six pillars of construction details "the rabbit" nuclear energy "warm baby" helped make it through more than 40 more of the Moonlight)
晨报记者杨育才
“嫦娥奔月”即将迎来最精彩动人的一刻。按照“奔月”时间表，嫦娥三号将于12月14日在月球表面的虹湾着陆，并开始为期3个月的月面巡视勘察。
嫦娥三号将在月球上遇到哪些恶劣的环境？它将依靠什么能源在月面维持“生命”？“玉兔”月球车将如何在月面巡视工作？如何将收集到的图片、资料等信息传回38万公里之外的“娘家”地球？近日，晨报记者采访了中国航天科技集团第八研究院804、805、811所多位专家，他们代表着上海的航天实力，参与了嫦娥三号月球车的研制。
疑问1：要去的月面环境如何？
“玉兔”要承受“月宫”300多摄氏度温差，1/6g重力环境
传说中的“月宫”美妙绝伦，嫦娥会带着玉兔在月宫里翩翩起舞。但在真实的月球上，没有空气，没有水，只有高达300多摄氏度的温差。
12月2日凌晨，嫦娥三号搭乘长征三号乙遥二十三运载火箭，从西昌卫星发射中心开始其登月之旅。在经过发射阶段、地月转移段、环月段以及动力下降段之后，嫦娥三号将会在月球表面软着陆。
在接受晨报记者采访时，中国航天科技集团第八研究院第805所专家介绍说，温差是登月后的嫦娥三号首先要面对的考验。月球车的车轮、摇臂等活动部件都是金属材质，具有热胀冷缩的特性，这就对材质和加工精度提出了很高要求。如果膨胀过度，活动部件容易出现卡死等故障。
除温差外，月球1/6g的重力环境，也是一大考验。设计师表示，月球表面的土壤非常松软，而且还凹凸不平，甚至还有陡峭的高坡。在这种重力环境下，月球车巡视过程中不仅要保持平稳，还要具备较好的通过性，更不能侧翻。
在第八研究院的月表形貌综合模拟试验控制室里，科研人员在模拟月壤上进行的各项试验；1/6g重力环境则通过跟随吊挂来实现，使得月球车只有1/6的重量压在模拟月面上。
此外，月表细小的月壤还会形成悬浮颗粒，并且因为月壤带有静电，容易吸附在月球车的车轮上，这对月球车活动部件的密封提出了非常高的要求。“如果这些颗粒或沙尘进入轴承，轻则增加摩擦力，重则卡死轴承，影响月球车机动性。”
疑问2：“玉兔”到站如何“下车”？
有“梯子”，下车全靠自身程序，风险还不小
整个“玉兔”月球车由移动、结构与机构、导航控制、综合电子、电源、热控、测控数传和有效载荷共8个分系统组成。
中国航天科技集团第八研究院巡视器移动分系统设计师介绍说：“这个分系统包括6个车轮、摇臂和差动机构，就像是汽车的底盘一样。”正是有了这个移动分系统，“玉兔”才能走下着陆器，在月表前进、后退、原地转向、行进间转向，还能爬上20度的坡道，越过20厘米高的障碍。
“着陆器释放月球车的过程，是一个比较大的难点。”上海航天专家胡震宇介绍说，从发射到月球着陆，月球车都是固定在着陆器顶部的。当着陆器着陆后，转移机构悬梯解锁，然后月球车和着陆器连接部分解锁，展开太阳能帆板并转移到悬梯顶端，最后，悬梯带着月球车往下转移，直至悬梯前端触碰月面，月球车才沿着梯子下滑到月球表面。
“之所以说这个步骤比较难，是因为月球车沿悬梯运动过程中存在着一些不可控的风险。”尽管着陆器会选择一块尽量平坦的地方着陆，但梯子伸出来的姿态比较难以控制，有可能会出现倾斜。月球车在下滑时，完全依靠自身既定的程序进行，速度会非常缓慢，但是其方向和速度都不受地面控制。
“从国际探测数据来看，世界各国对月球的探测共进行了129次，成功率是51%。从这些数据来看，探月活动风险还是很大的。”在11月26日举行的嫦娥三号任务首次新闻发布会上，探月工程副总指挥李本正表示，等月球车和着陆器落到月球上的时候，月球车从着陆器上走下来，是一个比较难的过程，也是一个非常重要的亮点。
为保证月球车能够平安地下滑到月球表面，巡视器移动分系统的科研人员进行了上千次的地面试验，以模拟验证各种姿态下的释放过程。李本正在发布会上表示，虽做了很多模拟，但对月球上的认识还是不完全和不充分的，所以存在着一定风险，也对执行任务的过程做了相应预案。
疑问3：“玉兔”在月宫如何作息？
长达14天的白天和黑夜，只有月昼在工作，所以，“玉兔”3个月任务期里将“半睡半醒”
当月球车离开着陆器，踏上月球表面之后，就进入了月面工作阶段。据李本正介绍，嫦娥三号的着陆器和月球车上各搭载了4种有效载荷，对月面、月表进行勘察。
月球车在月表如何工作呢？设计师透露，在短距离的行进中，月球车能够自主导航；但是远距离、大范围的巡视，就需要地面来设定行进路线。“月球车每走一小段，都会给地面一个反馈，包括图片或者数据，地面根据这个反馈再形成一个路径规划，通过指令指挥月球车前进、后退或者转弯。”
根据此次探月规划，嫦娥三号将在月球进行为期3个月的探测。但由于月昼和月夜的原因(月球上的一昼夜相当于地球上的28天，一夜相当于地球上14天)，“玉兔”月球车实际上只有月昼时间在工作，月夜里则处于休眠状态。
在月球表面巡视的3个月中，“玉兔”将依靠各种先进设备，对月表进行三维光学成像、红外光谱分析，开展月壤厚度和结构的科学探测，最深可以探测月表下100米深处，对月表物质主要元素进行现场分析。它传回来的数据，将帮助人们更直接、更准确地了解神秘的月亮。
疑问4：如何“睡眠”和“唤醒”？
通过地面测控人员指令，“玉兔”在“日落”时太阳能电池板收拢，防体温流失进入休眠状态，“日出”开始供电，由休眠唤醒模块唤醒
在接受晨报记者采访时，承担嫦娥三号电源分系统的中国航天科技集团第811所副所长钱斌介绍，嫦娥三号月球车的电源分系统，由太阳能电池阵、一组锂离子蓄电池、休眠唤醒模块和电源控制器组成。当着陆探测器实现在月球表面软着陆后，首先由着陆器为月球车充电，对月球车进行初始化。“太阳能电池阵就像是发电厂，电源控制器则用于管理发电厂生产出来的电，除了提供给着陆器和月球车使用，还要用来给锂离子电池充电。”钱斌介绍说，由于月夜长达14天，锂离子电池即便充满也无法满足月球车连续工作14天的需要，因此只能休息。按照设计，当太阳光线和月球车所在月面的夹角低于5度时，地面测控人员就会发出指令，将月球车一侧的太阳能电池板收拢，包裹在月球车箱体外部，防止体温在月夜里通过辐射流失。另一侧的电池板则调整角度，对准日出的方向。“月球车进入休眠状态后，电源将关闭，以节省电力。”
钱斌介绍说，14天的月夜结束后，月昼开始。当太阳升到月面5度时，原本伸展开的那个太阳能电池板开始供电，休眠唤醒模块就会唤醒月球车，重新开始工作。“可以说，月球车的‘日落而息’，是由地面控制的；‘日出而作’，就得靠月球车自己醒来。”
根据任务规划，月球车将在月表执行为期3个月的任务。“我国的航天器设计寿命一般都远远高于任务期，所以虽然任务期只有三个月，但三个月后月球车还将能继续工作。”钱斌介绍说，影响航天器寿命的因素主要有两个，首先是能量系统，无论镍镉电池、锂离子电池还是太阳能电池，都会随着时间而衰减；其次是航天器的机械部件，会随着时间加长而逐步老化或者出现故障等。
疑问5：在月宫如何“保暖”？
“月兔”怀揣核能“暖宝宝”，此外，其身裹的一层金色“外衣”也是抵御温差的“法宝”
除了休眠唤醒模块外，嫦娥三号的另一大亮点是它携带了一个同位素热源。这也是我国航天器首次利用核能源。“目前主要采用钚-238，它在衰变过程中辐射出高能粒子可为热能材料提供热能，使舱内设备的温度保持在零下50℃以上。”钱斌告诉记者，嫦娥三号所携带的同位素，还仅仅是作为热源使用，未来嫦娥四号上或将安装放射性同位素温差电源，利用携带的同位素来供热并发电。
钚-238同位素的半衰期非常漫长，可以长达80多年，因此是星际探测器最理想的能源。“在星际探测时，距离太阳越远，阳光越弱，太阳能电池不能有效工作，这时就需要利用放射性同位素温差电源。”
美国的“旅行者”、“好奇号”火星探测器都采用了钚-238同位素温差电源作为热电能源。钱斌介绍说，“旅行者”探测器发射至今已经36年，但它所携带的同位素温差电源输出功率仅仅衰减了不到40%。“之所以采用钚-238同位素，是因为这种同位素半衰周期足够长，而且其裂变产物为较大的α粒子，穿透性相对较弱，安全性就更高。”
月球车上裹着的那层金色“外衣”，也是“玉兔”抵御温差的“法宝”。白天能反射强烈的阳光，降低箱体的温度；晚上则能防止车上箱体热量散发导致体温过低。
疑问6：如何和“娘家”联系？
将用深空 “无线宽带”回传数据，平均每秒1M左右速度传回地球
“如果将嫦娥三号比作是一只飞上月球的风筝，测控数传分系统就是风筝线。”中国航天科技集团第八研究院某专业技术研究所主任设计师告诉记者。该所承担了嫦娥三号巡视器(即月球车)测控数传分系统。“通过这根无形的‘风筝线’，地面的工作指令能传达到月球车；月球车在勘察中采集到的数据、图片等也通过这根‘线’回传到地球。”
据介绍，通过这套数传分系统，月球车采集到的数据，可以按照平均每秒1M左右的速度传回地球。这在38万公里的距离上，已经是速度很快的“无线宽带”了。
要达到这样的速度，月球车的天线必须具备足够大的体积和辐射性能。该所的科研人员提出了一个创造性方案，将天线当作月球车的桅杆，既可以收发信号，还能支撑全景相机。“这个新型方案有很多好处。首先，定向天线和全景相机不会相互干涉，定向天线实现了半球空间无遮挡高增益辐射性能，能向地面传输大量数据，而全景相机也获得了全视场成像无遮挡；另外，天线和桅杆合二为一后，能充分利用月球车有限的空间，并且天线支架采用碳纤维材料，也能降低月球车的重量。”该设计师说。
将天线当作桅杆，解决了发射功率和大容量传输的问题，但另一个问题随之而来。“月球车面临的环境，比地球轨道卫星的环境要恶劣很多。”他说，地球轨道卫星绕一圈也就2小时左右，有的还不到2小时，也就是说卫星朝阳和背阴时间都不长，卫星经历的环境温差不会很大。但月球有月昼和月夜，14天才白天黑夜交替一次，由此形成了300摄氏度左右的高温差。“天线需要全程工作，又不能装进‘保温箱’，只能安装在月球车外部，暴露在月球表面。这就必须要能经受最高150摄氏度、最低零下180摄氏度的温差考验。”
为此，科研人员进行了大量高难度的地面验证试验，如热真空试验和液氦环境下的低温存贮试验，充分验证了天线在月球表面巨大温差下的环境适应能力。
(原标题：六大释疑详解“玉兔” 核能“暖宝宝”助熬过40多个月夜)
赞