at 15:22 from Xichang. The Beidou 3 navigational system consist of 24 MEO, 3 GEO, 3 IGSO satellite constellation to provide world wide coverage. With this Dec 16 launch, all 24 earth orbit MEO satellites are launched. There're only two remaining GEO Beidou satellites due to launch in the first half of 2020 and the whole Beidou 3 constellation would be completed.
BTW, just in case someone asked, the 52th, 53th include counting the Beidou 1 and 2 satellites.
