In this paper, obtained the translunar trajectory for direct striking the moon, which satisfied some constraints including translunar flight time, lunar landing date.

在给定飞行时间、着月时间、着月入射角及停泊轨道等约束条件下，建立飞月轨道数学模型；

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The more difficult second level requires a flight of 180 seconds followed by a landing on simulated lunar terrain, complete with rocks and craters.

更困难的第二个级别，要求飞行180秒，接着在遍布岩石和陨石坑的模拟月球地形上降落。

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From the return pulse, LOLA determines the time of flight which, accounting for the speed of light, reveals the distance from the spacecraft to the lunar surface.

之后激光高度计将参照光速，计算出反射脉冲的渡越时间，从而获得飞船与月球表面之间的距离。

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During the flight, they separated the lunar lander from the command module and flew it for eight hours.

VOA: special.2009.07.08

"There's no physical difference in the moon, " said Noah Petro, scientist for the Lunar Reconnaissance Orbiter at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

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The enigmatic "Mona Lisa" countenance was digitized and traveled via laser almost 240, 000 miles from NASA's Goddard Space Flight Center in Greenbelt, Maryland, to the Lunar Reconnaissance Orbiter.

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