Yesterday, 5 Nov 2017, at 19:45 Beijing time (GMT+8), China successfully launched its first two BeiDou navigation satellites of 2017. This took place at Xichang Satellite Launch Center using the three-stage Long March 3B, marking China’s first use of the rocket since June 2017, during which ChinaSAT 9A was placed in the wrong orbit.
The two satellites, BeiDou-24 and BeiDou-25 (also known as Beidou-3M1 and Beidou-3M2), are twin satellites working in tandem at Medium Earth Orbit (MEO). These are equipped with new generation atomic clocks, and offer positioning accuracy of up to 2.5 meters to 5 meters. The satellites have a design life of 10-12 years and are expected to provide uninterrupted service.
According to the China Aerospace Science and Technology Corporation (CASC), this launch opens a “new era” for BeiDou, as it paves the way for the constellation to achieve global coverage. Unlike the previous BeiDou-2 constellation, which provided regional coverage, BeiDou-3 uses phased arrays to establish communication links between the satellites, enabling the monitoring of all satellites. The satellites are also equipped with Receiver autonomous integrity monitoring (RAIM) to detect faults in the system.
With these, China hopes to make BeiDou global by 2020. By next year, the constellation is expected to serve “Belt and Road” countries. Including the two launched yesterday, China now has 9 satellites in its BeiDou-3 constellation, along with 13 satellites from its BeiDou-2 constellation.