THE NEW SPACE RACE: China’s Shijian spacecraft separate after pioneering geosynchronous orbit refueling tests.

China’s experimental Shijian-21 and Shijian-25 satellites have separated in geosynchronous orbit after being docked for months conducting apparent low-profile on-orbit refueling tests.

Shijian-21 and Shijian-25 performed rendezvous and proximity operations during the first half of the year before apparently docking in late June or early July, when the pair became virtually indistinguishable when viewed from the ground, likely marking the start of planned refueling tests, according to independent satellite-tracking analyses. The docked pair then later performed fuel-intensive orbital plane change maneuvers, reducing their orbital inclination.

Optical ground observations Nov. 29 made by S2a systems, a Swiss company which develops and operates customized systems for optical space surveillance worldwide, reveal that the two satellites have now separated in geosynchronous orbit, close to the geostationary belt (GEO) at 35,786 km above Earth’s equator. The orbits of the pair are inclined by 4.6 degrees with respect to GEO.

The separation could mark a successful conclusion to a world-first refueling operation in GEO.

Beijing appears to be working very hard at making their space systems robust.