On March 30, 2015, China Aerospace Science and Technology Corporation (CASC) conducted successful launch of Long March-3C launch vehicle with a satellite for BeiDou Navigation Satellite System (BDS) from Xichang Satellite Launch Center in the southwest China's Sichuan Province.
The mission orbited the 17th satellite of BeiDou orbital constellation and marked beginning of expansion from regional to global coverage. The latest satellite is expected to test a new type of navigation signaling and inter-satellite links, providing a basis to start building the global network.It is planned that BeiDou satellite constellation will consist of 35 spacecraft – 5 at geostationary orbit, 27 at medium Earth orbit (MEO), and the remaining 3 at an inclined geosynchronous orbit. As a comparison, US GPS and Russian Glonass navigation satellites are only MEO-orbiting. Spaceflight Now suggests that, considering the flight path of Long March-3C, the latest BeiDou spacecraft was launched in an inclined orbit.
BeiDou navigation system is a collective name for three generations of 'sub-systems'. The first is BeiDou Satellite Navigation Experimental System, or BeiDou-1. It consists of three satellites and offers limited coverage and applications. It has been offering navigation services, mainly for customers in China and neighboring regions, since 2000.
The second generation of the system, also known as COMPASS or BeiDou-2, has been developed since 2007. In December 2012, it began providing positioning, navigation, timing and short message services to civilian users in China and parts of the Asia-Pacific. The system has been gradually introduced into transportation, weather forecasts, marine fishing, forestry and telecommunications.
Some sources reported that the latest launch was of the third-generation BDS spacecraft. Xinhua News Agency, though, calls it just a 'new-generation satellite' for BeiDou system.
The new satellite, having mass of around 1 ton, was developed by Shanghai Engineering Center for Microsatellites, a non-profit organization established by the Chinese Academy of Sciences and the Shanghai Municipal Government. According to Yang Changfeng, chief designer of BDS, the latest satellite has service life of up to 12 years and maximum accuracy of 2-3 meters, better than its predecessors.The latest launch also marked the maiden flight of new upper stage YZ-1, or Yuanzheng. Similarly to Russian Fregat, Briz and DM upper stages, it is said to have capacity to perform orbit-raising for the carrying satellite or satellites from intermediate to geostationary orbit. Not only for Yuanzheng, that was also the first mission for China when it has used such technology to raise spacecraft from medium into a high orbit.
Photos above retrieved from Xinchua News Agency.
According to iCrossChina, the country plans to launch three or four more BeiDou satellites this year. A complete network is expected to be formed by 2020.