英语热词 | “鹊桥”号成功发射 the second Lagrangian (L2) point of the Earth-Moon system

21日5时28分,我国在西昌卫星发射中心用长征四号丙运载火箭,成功将探月工程嫦娥四号任务“鹊桥”号中继星发射升空。

英语热词 | “鹊桥”号成功发射
A Long March-4C rocket carrying a relay satellite, named Queqiao, is launched at 5:28 am Beijing Time from Southwest China's Xichang Satellite Launch Center, May 21, 2018.[Photo/Xinhua]
中国于21日凌晨发射中继卫星,将为将来实施的嫦娥四号月球背面软着陆探测任务提供地月间的中继通信。China launched a relay satellite early Monday to set up a communication link between Earth and the planned Chang'e-4 lunar probe that will explore the mysterious far side of Moon, which can not be seen from Earth.

The satellite, named Queqiao (Magpie Bridge), was carried by a Long March-4C rocket that blasted off at 5:28 a.m. from southwest China's Xichang Satellite Launch Center, according to the China National Space Administration (CNSA).

据中国国家航天局消息,这颗卫星名为鹊桥,由长征四号丙运载火箭于5时28分在西昌卫星发射中心发射升空。

这是世界首颗运行于地月拉格朗日L2点(简称地月L2点)的通信卫星,将为2018年底择机实施的嫦娥四号月球背面软着陆探测任务提供地月间的中继通信。

"The launch is a key step for China to realize its goal of being the first country to send a probe to soft-land on and rove the far side of the Moon," said Zhang Lihua, manager of the relay satellite project.

中国航天科技集团有限公司五院“鹊桥”号中继星项目经理张立华说,“鹊桥的发射是中国成为首个实现探测器月球背面软着陆和巡视勘察的国家的关键一步。”

长征四号丙运载火箭飞行25分钟后,星箭分离,将“鹊桥”直接送入近地点高度200公里,远地点高度40万公里的预定地月转移轨道,卫星太阳翼和中继通信天线相继展开正常。

About 25 minutes after liftoff, the satellite separated from the rocket and entered an Earth-Moon transfer orbit with the perigee at 200 km and the apogee at about 400,000 km. The solar panels and the communication antennas were unfolded.

perigee ['peridʒi:]:近地点

apogee ['æpədʒi]:远地点

后续,“鹊桥”将经中途修正、近月制动和月球借力,进入月球至地月L2点的转移轨道,通过3次捕获控制和修正后,最终进入环绕地月L2点的使命轨道,地月L2点是卫星相对于地球和月球基本保持静止的一个空间点。

Queqiao is expected to enter a halo orbit around the second Lagrangian (L2) point of the Earth-Moon system, about 455,000 km from the Earth.

It will be the world's first communication satellite operating in that orbit.

科普:地月拉格朗日L2点

the second Lagrangian [lə'grændʒiən] (L2) point of the Earth-Moon system

拉格朗日点又称为平动点,于1772年由法国数学家拉格朗日推算得出,是指一个小物体在两大物体的引力作用下,小物体相对于它们基本保持静止的空间点。

该空间点有五个,分别为L1、L2、L3、L4、L5。在拉格朗日点上,探测器消耗很少的燃料即可长期驻留。

英语热词 | “鹊桥”号成功发射
“鹊桥”号中继星项目经理张立华说,“鹊桥”还携带了由荷兰研制的低频射电探测仪,未来将开展在轨科学探测试验。

执行此次发射任务的长征四号丙运载火箭是长征四号系列运载火箭第一次在西昌卫星发射中心承担发射任务。这是长征系列运载火箭第275次发射。此次还搭载发射了“龙江一号”“龙江二号”两颗月球轨道编队超长波天文观测微卫星。

为什么要搭建地月“鹊桥”?

由于月球绕地球公转的周期与月球自转的周期相同,所以月球总有一面背对着地球,这一面称之为月球背面。

着陆在月球背面的探测器由于受到月球自身的遮挡,无法直接实现与地球的测控通信和数据传输。

“鹊桥”号中继星将在地月连线延长线的L2点附近,围绕L2点飞行,实现对地、对月中继通信,保障嫦娥四号任务实施,其到月球的平均距离约为6.5万公里,距地球40多万公里。

Chinese scientists and engineers hope the Queqiao satellite will form a communication bridge between controllers on Earth and the far side of the Moon where the Chang'e-4 lunar probe is expected to touch down later this year.

中国科学家和工程师希望“鹊桥”号中继星能够成为架设在月球背面与地球之间的“通信中继站”。嫦娥四号月球背面软着陆探测任务将在年底择机实施。