Two Compass Satellites Launched

News courtesy of CANSPACE Listserv.

China successfully launched two BeiDou-2/Compass MEO satellites Tuesday at 19:10:04 UTC. The satellites are designated Compass-M5 and Compass-M6. They are also referred to BeiDou-14 and BeiDou-15.

UPDATE: More details have emerged on yesterday’s BeiDou-2/Compass satellite launch. According to Web sources, the new satellites will occupy slots 7 and 8 in Plane A of the Compass MEO orbit design. The existing operational Compass MEO satellites, MEO-3 and MEO-4 occupy slots 3 and 4 in Plane B, 120 degrees to the west of Plane A. The Compass MEO constellation will eventually consist of 24 primary satellites, eight in each of three equally spaced planes. It is reported that the satellites now use Chinese-made atomic clocks.

The exact time of yesterday’s launch was 19:10:04.179 UTC. NORAD/JSpOC is tracking four objects from the launch: the satellites, the adapter, and the third stage of the launch vehicle. They are all in elliptical transfer orbits at the present time and the satellites will likely transfer to their MEO orbits within the next few days.

According to a Compass official, the current generation of Compass navigation satellites has a predicted lifetime of eight years. This will be increased to 11-12 years for future models.

Compass managers now claim that the 5 GEO + 5 IGSO +4 MEO initial configuration will have good robustness and economic efficiency for such a regional navigation system. They state that “[T]he four MEO satellites increases the repeat coverage for users: the probability for position dilution of precision being less than three is now at 74.89 percent for more than 23 hours per day, up from 38.55 percent earlier this year.”

The final Compass GEO satellite for the initial constellation deployment, GEO-6, is scheduled for launch in October of this year.

CCTV-13 video report of the launch:
http://www.youtube.com/watch?v=brzO8UtnXEM