Ground-based imagery now suggests China has completed a docking and undocking of two robotic servicing satellites
According to ground-based imagery by the commercial company S2A, China’s Shijian-21 and Shijian-25 robotic servicing satellites appear to have completed a docking and undocking on June 13 and June 14, 2025.
China’s Shijian-21 and Shijian-25 satellites had been moving toward each other in geosynchronous orbit, around 22,236 miles (35,786 kilometers) above the equator, Spacenews reported on June 6. And now the pair appear to have had a brief first encounter, according to observations from the ground.
Optical tracking by the space situational awareness firm s2a systems shows a close approach between the two on June 14, with the pair, at times, virtually unresolvable from the other. This suggests that Shijian-21 and Shijian-25 made at least a test-run close approach and may have even performed a docking and undocking test.
You can see video of the first apparent docking here.
Shijian-21 was launched in 2021, and was used to grab a defunct Chinese geosynchronous satellite and tug it to a graveyard orbit. Shijian-25 was launched in January 2025 to test robotic servicing of satellites. These maneuvers with Shijian-21 appear to be part of those tests.
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According to ground-based imagery by the commercial company S2A, China’s Shijian-21 and Shijian-25 robotic servicing satellites appear to have completed a docking and undocking on June 13 and June 14, 2025.
China’s Shijian-21 and Shijian-25 satellites had been moving toward each other in geosynchronous orbit, around 22,236 miles (35,786 kilometers) above the equator, Spacenews reported on June 6. And now the pair appear to have had a brief first encounter, according to observations from the ground.
Optical tracking by the space situational awareness firm s2a systems shows a close approach between the two on June 14, with the pair, at times, virtually unresolvable from the other. This suggests that Shijian-21 and Shijian-25 made at least a test-run close approach and may have even performed a docking and undocking test.
You can see video of the first apparent docking here.
Shijian-21 was launched in 2021, and was used to grab a defunct Chinese geosynchronous satellite and tug it to a graveyard orbit. Shijian-25 was launched in January 2025 to test robotic servicing of satellites. These maneuvers with Shijian-21 appear to be part of those tests.
Readers!
My annual February birthday fund-raising drive for Behind the Black is now over. Thank you to everyone who donated or subscribed. While not a record-setter, the donations were more than sufficient and slightly above average.
As I have said many times before, I can’t express what it means to me to get such support, especially as no one is required to pay anything to read my work. Thank you all again!
For those readers who like my work here at Behind the Black and haven't contributed so far, please consider donating or subscribing. My analysis of space, politics, and culture, taken from the perspective of an historian, is almost always on the money and ahead of the game. For example, in 2020 I correctly predicted that the COVID panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Every one of those 2020 conclusions has turned out right.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
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Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
Perhaps the grim and humorless do make the best aerospace engineers after all.