Launched as a designated experimental satellite on November 3, 2016, Shijian 17 (SJ-17) quickly relocated several times in the GEO belt. Since Chinese media reported that SJ-17 would have chemical propulsion and on-board surveillance sensors to perform technology demonstrations, the maneuvers soon after arrival were not wholly unusual. What is unusual is the number of close approaches SJ-17 has made over its lifetime with other satellites. Only nine days after its launch date, SJ-17 rendezvoused with Chinasat 5A, a Chinese communication satellite launched in 1998. More information on Chinasat 5A here.
SJ-17 initiated a westward drift on December 29, 2016 and relocated next to another Chinese communications satellite, Chinasat 6A, in June 2017. From late June through early July, SJ-17 continued to perform close RPO maneuvers with Chinasat 6A. The nearest approach on record was on July 1, when the two satellites were 1.67 km apart. The two satellites remained in close proximity for about a week, never exceeding 15km from one another until July 6th. The image below shows the several records of varying close distances the two satellites maintained over the course of that time.
Since it arrived in the GEO belt in 2016, SJ-17 has moved to park next to or interact with several other satellites, the majority of which were also Chinese. Learn more about SJ-17’s behavior here.