5月17日10时49分,我国在西昌卫星发射中心用长征三号乙运载火箭,成功发射第56颗北斗导航卫星。该卫星由中国航天科技集团有限公司五院研制,属地球静止轨道卫星,是我国北斗三号工程的首颗备份卫星。请看本报周四的报道: China on Wednesday sent a new BeiDou navigation satellite into space from the Xichang Satellite Launch Center in Southwest China’s Sichuan Province. The satellite was launched at 10:49 a.m. (Beijing Time) by a Long March-3B carrier rocket. The satellite, designed to enter geostationary earth orbit, is the 56th of the BeiDou family and also the first backup satellite for the country’s BeiDou-3 Navigation Satellite System (BDS-3). 报道中的geostationary earth orbit (GEO)就是地球静止轨道。当同步轨道卫星轨道面的倾角为零度,即卫星在地球赤道上空运行时,由于运行方向与地球自转方向相同,运行周期又与地球同步,因此,人们从地球上仰望卫星,仿佛悬挂在太空静止不动,所以,把零倾角的同步轨道称作静止轨道,在静止轨道上运行的卫星称作静止卫星。 |