Photo: Courtesy of CALT

The launch window of the last satellite in China's domestically developed BeiDou Navigation Satellite System, or BDS, has been finalized for between 10:11 am and 10:50 am on Tuesday, according to an official announcement on Monday.

The announcement of the launch window signifies that all preparation work for the mission has been completed, with the Long March-3B carrier rocket and the third geostationary Earth orbit (GEO) satellite, which is also the 30th of the third-generation series of the BeiDou system, or BDS-3, in stable and reliable status before the launch, insiders told the Global Times on Monday. 

All rocket and spacecraft performance indicators have met launch requirements, and injection of propellants for the rocket was initiated on Monday morning, about 24 hours before the launch window, they noted.

China's Yuanwang-6 spacecraft tracking vessel, which is tasked with seaborne measuring and control work for the Tuesday mission, has arrived in the designated waters in the Pacific Ocean, Global Times learned from the space authority. 

The Yuanwang-6 will be the only vessel to conduct tracking observation at sea for the mission, and marks the ship's 14th BeiDou mission. 

Ground monitoring radar units for the mission have also been locked in, and are ready for the Tuesday mission. 

The latest GEO satellite is the 55th BDS system, and will work with other members of the network, allowing global users to access high-accuracy navigation, positioning and timing as well as communication services.

Compared to previous generation series, the constellation of BDS-3 with an array of 30 satellites flying on three different orbit planes - three at the GEO, three at the inclined geosynchronous orbits, and 24 at the medium Earth orbit - have higher bandwidth, enabling enhanced communication capability and carrying more accurate and stable domestically developed atomic clocks to improve the precision of timing and navigation services, according to the project contractor China Academy of Space Technology under the state owned space giant China Aerospace Science and Technology Corporation (CASC). 

The first BeiDou satellite entered orbit in 2,000, and started providing positioning, navigation, timing and messaging services to domestic users in China and users in the Asia-Pacific region in December 2012.

The BDS system started providing global services at the end of 2018, when construction of the BDS-3 primary system had been completed. 

The Tuesday mission will complete the BDS-3 system, which, according to Wu Di, a scholar with the satellite positioning technology center of Wuhan University in Central China's Hubei Province on Monday, will further enhance the quality of services of the system for global users with more satellites above every corner around the globe, which will bring stronger signals.