Monday saw the seventh orbital launch of the year by China, with a Long March-3B/YZ-1 orbiting a new pair of navigation satellites. The launch took place just after 05:00 UTC from the LC2 Launch Complex of the Xichang Satellite Launch Center, Sichuan province. It took over four hours to complete the mission.
It is expected that the Beidou-3MEO3 (Beidou-28) and Beidou-3MEO4 (Beidou-29) satellites were onboard. The MEO satellites are the Medium Earth Orbit component of the third phase of the Chinese Beidou (Compass) satellite navigation system. The satellites are part of a fleet that will expand the system to a global navigation coverage.
The satellites are using a new bus that features a phased array antenna for navigation signals and a laser retroreflector, with a launch mass 1,014 kg. Spacecraft dimensions are noted to be 2.25 by 1.0 by 1.22 meters. Usually, the satellites reside in a 21,500 – 21,400 km nominal orbit at 55.5 degrees.
The previous launch on the series took place on January 12th, when the Long March-3B/Y1 (Y45/Y5) launch vehicle orbited the Beidou-3MEO7 (Beidou-26) and Beidou-3MEO8 (Beidou-27) satellites. On November 5, 2017, the Long March-3B/Y1 (Y46/Y4) orbited the Beidou-3MEO1 (Beidou-24) and the Beidou-3MEO2 (Beidou-25) satellites.