XICHANG, Nov. 19 -- China sent two new satellites of the BeiDou Navigation Satellite System (BDS) into space on a Long March-3B carrier rocket from the Xichang Satellite Launch Center in Sichuan Province at 2:07 a.m. Monday.
The satellites entered a medium earth orbit more than three hours later and will work with 17 other BDS-3 satellites already in space. They are also the 42nd and 43rd satellites of the BDS satellite family.
With the successful launch, the basic BDS constellation deployment is complete. China plans to provide navigation services with the BDS-3 to countries participating in the Belt and Road Initiative by the end of this year.
"This is a key step for BDS developing from a domestic experimental system to a regional and then a global navigation system," said Yang Changfeng, chief designer of the BeiDou system.
The positioning accuracy of the BDS-3 system has been improved to 2.5 meters to 5 meters, up to twice as high as the BDS-2 system, said Yang.
Named after the Chinese term for the Big Dipper constellation, the BeiDou system started serving China in 2000 and the Asia-Pacific region in 2017.
China plans to launch another six BDS-3 satellites to the medium earth orbits, three satellites to the inclined geosynchronous earth orbit and two satellites to the geostationary earth orbit from 2019 to 2020.
The system will provide first-class services around the globe by the end of 2020.
[定语从句]关系代词引导的定语从句
英语阅读基本功—长难句过关(6)
英语阅读基本功—长难句过关(9)
英语阅读基本功—长难句过关(5)
[定语从句]关系副词引导的定语从句
[状语从句]表示"一…就…"的结构
英语阅读基本功—长难句过关(7)
句子重音知多少
[连词]表示选择的并列结构
[虚拟语气]It is (high) time that
[连词]表原因关系
英语阅读基本功—长难句过关(3)
英语阅读基本功—长难句过关(8)
[定语从句]介词+关系词
英语阅读基本功—长难句过关(13)
动名词考试要点详解
[情态动词] should 和ought to
[状语从句]原因状语从句
英语阅读基本功—长难句过关(2)
[状语从句]比较until和till
[虚拟语气]特殊的虚拟语气词should
英语阅读基本功—长难句过关(12)
[情态动词]比较may和might
[情态动词]带to 的情态动词
[虚拟语气]need "不必做"和"本不必做"
英语阅读基本功—长难句过关(14)
[状语从句]比较while, when, as
[状语从句]结果状语从句
[情态动词]will和would
[连词]比较and和or
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