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The author:(作者)hpmailerpublished in(发表于) 2013/12/5 11:05:35 Exploration Rover desert test site
There are low, soft sand and dunes, where unusually dry, barren, hot cold at night during the day, this is where most like the moon. Junction of the kumtag desert and Lop Nur in Northwest China, scientists have established a testing ground. Be walked on the Moon, "the rabbit" Rover here, through a variety of tests.
Why test in the desert? Field testing Rovers
Chang, third Deputy designer of the lunar probe said Jia Yang, Moon patrol also developed in China for the first time. In order to ensure that tasks are completed, designers carried out many ground tests and field trials is one of the most important of them.
"In our laboratories which simulates a real lunar surface as much as possible, to fully inspect the performance of the verification. But the environmental operations personnel are familiar with, even in the absence of clear image information, also can draw on experience to control visits. "Jia Yang said.
He said: "in order to avoid this problem, we are going to the outfield to rule an unknown environment, operators do not see obstacles, completely judging by image processing and manipulation of inspections. In addition, the laboratory within a limited space, desert on the moon to test long-distance driving, examining the detection capability of the vehicle, cars can go up to the moon away from the stage. "" The rabbit ", weighs about 140 kilograms of Lunar Rover, there are 6 drive wheel, stones may move across the 20 cm high, fast 3.3 meters per minute.
Scheduled to become immortal, the third will be held in mid-December at Rainbow Bay, a relatively flat region of the moon landing, white space is other countries have not been up here.
Test site selected? Ran all of China's desert
Researchers undertook a comprehensive analysis of geographical, meteorological information, identifying the Chinese might meet the requirements of the test sites.
"We took into account several factors. "Jia Yang," said first of all sand grains to fine, Lunar soil particles with an average diameter of 70 microns, fall hair almost. ”
"And secondly we must select the most arid desert. Some underground contains water in the desert, sand has compacted. China's desert area is relatively large, but a lot is covered with grass, which is that we don't expect, because there is no grass on the moon. So we select the rainfall is minimal. "Jia Yang said.
In addition, also have a test requirement is not the wind, because there is no wind on the moon. "We checked all the average wind speed of the desert selection during the pilot season where minimum average wind speed. ”
Experts ran about 20,000 km, considering the mechanical properties of soils, climate, vegetation and test aspects such as confidentiality, security, and ultimately decide the kumtag desert and Lop Nur near the akchi Valley at the junction of the outfield experiment. "We ran all of the desert, this is the best meet our requirements. "Jia Yang said.
Kumtag desert is China's sixth largest desert, is located in the southern edge of Lop Nur depression, Tarim basin, and Mingsha in Dunhuang, Gansu province in the East, and is bounded by akchi Valley, the South is bounded by Altun, 22800 square kilometers of the total area.
The desert test
Dig "craters" simulated lunar surface
Test persons in about 3 square kilometres of the region, according to Chang, first and second on the lunar surface exploration data as well as the United States "Apollo" spacecraft images taken on the Moon, on the test site was modified.
Responsible for the construction of Duan Hailin describes: "we in accordance with drawings, a certain degree of slope in the sand, dug up in accordance with standard sizes and more than more than 10 ' crater ', also features a number of stones.
Jia Yang said: "in addition to light and temperature conditions, we work as closely as possible on the surface. In order for the weight of the Lunar Rover on the Moon's surface as much as possible, we are part of the Rovers on electronic equipment was moved to another car, with connecting lines. ”
At the desert test site, researchers tested the Rovers driving short distance 10 meters and one kilometer long distance athletic ability. Another important point of testing is to find Moonlight sleep. "The Rover to find something that suits your requirements before the Sun stops, this stance is required for Lunar Rover, Rover reawakened when the sun rises. "Jia Yang said.
"The rabbit" how far is it to walk on the Moon, Jia Yang said: "the real Lunar Rover on the moon does not go very far, it was more and more in the detection, image. Images transmitted back to Earth, ground personnel but also with a considerable amount of time to plan a path, and verify that there are no problems on the ground, and then communicated to Rovers keep it moving. ”
这里有松软的细沙和低矮的沙丘，这里异常干燥、寸草不生，这里白天酷热夜晚寒冷，这里是中国最像月球的地方。在中国西北库姆塔格沙漠与罗布泊交界处，科学家们建立了试验场。即将漫步月球的“玉兔”号月球车就曾经在这里通过各种测试。
为何要在沙漠中试验？外场试验测试月球车
嫦娥三号月球探测器副总设计师贾阳说，中国研制月球巡视器还是第一次。为确保任务的完成，设计师开展了多项地面试验，外场试验是其中最重要的项目之一。
“我们在实验室中尽可能地模拟了真实的月球表面，对巡视器的性能进行了充分验证。但是这个环境操作人员非常熟悉，即使没有看到清晰的图像信息，也可以凭借经验控制巡视器。”贾阳说。
他说：“为避免这个问题，我们要到外场去构制一个未知的环境，让操作人员看不到各种障碍的情况，完全根据图像处理来判断并操控巡视器行进。此外，实验室内场地有限，沙漠中可以对月球车的长距离行驶、巡视探测能力进行试验，月球车可以走到公里级。”“玉兔”号月球车重约140公斤，有6个主动轮，可驶过20厘米高的石头，最快每分钟走3.3米。
按计划，嫦娥三号将于12月中旬在月球相对平坦的虹湾区着陆，这里是其他国家尚未勘察过的空白。
试验场如何选出？查遍了中国所有沙漠
科研人员全面分析了地理、气象资料，寻找中国可能符合要求的试验地点。
“我们综合考虑了几个因素。”贾阳说，“首先沙子的颗粒要细，月壤颗粒的平均直径是70微米，跟头发丝差不多。”
“其次我们要选最干燥的沙漠。有些沙漠地下含有水分，沙子会有板结。虽然中国沙漠面积比较大，但是很多地方都是有草的，这是我们不期望的，因为月球上没有草。所以我们选择降雨量最小的地方。”贾阳说。
此外，还有一个试验要求就是不能有大风，因为月球上没有风。“我们查了所有沙漠的平均风速，遴选在试验季节平均风速最小的地方。”
专家们跑了约2万公里，综合考虑了气候、植被、土壤力学性能、试验保密、生活保障等各方面因素，最终决定在库姆塔格沙漠与罗布泊交界的阿克奇谷地附近进行外场试验。“我们查遍了中国所有的沙漠，这里是最符合我们要求的。”贾阳说。
库姆塔格沙漠是中国第六大沙漠，地处塔里木盆地罗布泊洼地南缘，东至甘肃敦煌鸣沙山，北抵阿克奇谷地，南以阿尔金山为界，总面积约2.28万平方公里。
沙漠试验
挖出“陨石坑”模拟月面情况
试验人员在约3平方公里的区域内，依据嫦娥一号、二号对月球表面的探测数据以及美国“阿波罗”号飞船对月球拍摄的图像，对试验场进行了改造。
负责改造施工的段海林介绍：“我们按照图纸，在沙地上修出一定的坡度，又按照标准挖出大大小小十多个‘陨石坑’，还布置了一些石块。
贾阳说：“除了光照和温度条件，我们努力尽可能接近月面上的情况。为了让月球车的重量与在月球表面尽可能一样，我们把月球车上的一部分电子设备挪到其他车上，用线连接起来。”
在沙漠试验场中，科研人员测试了月球车10米短距离行驶，以及一公里长距离运动能力。另一个重要的试验是寻找月夜休眠点。“月球车要在太阳落山前找到一个符合要求的停靠点，这个点对月球车的姿态是有要求的，要让月球车在太阳升起时能重新唤醒。”贾阳说。
对于“玉兔”能在月球上走多远，贾阳说：“月球车真正在月球上不会走很远，它更多的时间是在探测、拍图像。图像传回地球，地面人员还要用相当长的时间来规划出一条路来，并在地面上验证没有问题后，再传达给月球车让它运动。”
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