In a high-stakes test, two Chinese spacecraft, Shijian-21 and Shijian-25, recently docked with each other about 22,236 miles above Earth in a demonstration of space refueling capabilities. S2A Systems, a space situational awareness company, tracked the maneuver in geosynchronous orbit and reported that the close approach took place on June 14, with initial activity observed on June 13.
Optical tracking measurements showed that the two satellites were so close that they were almost indistinguishable from one another, which implied a possible docking or undocking experiment. Chinese authorities have not officially announced docking, but the close proximity of the two vessels is a strong indication that they are testing on-orbit servicing methods, namely refueling and extending the life of a mission.
Shijian-25, launched in January 2024, was intended to prove these capabilities. Its accomplice in this maneuver, Shijian-21, was launched in 2021 and had earlier shown space debris control by towing a dead satellite to a higher graveyard orbit. The two satellites were designed by the Chinese state-owned Shanghai Academy of Spaceflight Technology (SAST).
The mission is another milestone in the Chinese quest to make long-term space missions more sustainable through in-orbit satellite servicing. These abilities would have the potential to lengthen the lifespan of satellites, minimize space debris, and enhance flexibility in the geosynchronous belt, a region that is very important in communications, weather tracking, and military surveillance.
Interestingly, the U.S. surveillance satellites USA 270 and USA 271 were also in the vicinity during the Chinese operation, probably spying on the activity. The U.S. has already experimented with similar technology in the form of the Mission Extension Vehicle program by Northrop Grumman, and Astroscale in Japan is also planning its own in-orbit refueling experiments in the near future.
With space getting busier and more strategic, this silent yet meaningful meeting in the stratosphere above the world could be the precursor of the next phase of satellite life and global rivalry in orbital servicing technology.
