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在2009年6月23日,NASA研制的造价为5.04亿美元的环月探测器(LRO)用了40分钟时间,成功地以椭圆形轨道环绕月亮一周后,停止了其推进器。这次重要的火箭推进活动在美国
On June 23, 2009, NASA developed a $ 504 million LRO that took 40 minutes to successfully stop its thrusters after a successful one-week oval orbit around the moon. This important rocket propulsion event is in the United States