China has reportedly completed the world’s first satellite refueling mission in space. Between June and July 2025, two Chinese satellites—Shijian-21 and Shijian-25—performed a series of carefully coordinated maneuvers in geostationary orbit about 22,000 miles above Earth. This orbit is crucial because it allows satellites to match the Earth’s rotation, making them ideal for communications and surveillance.
According to report from the South China Morning Post, the tracking data from U.S.-based company COMSPOC and Swiss firm s2a Systems, the two satellites appeared to dock and remained connected for several days. Experts say this indicates a successful fuel transfer, something no other country has achieved so far.
Shijian-25 launched in January 2025 to test satellite refueling technology in orbit. Shijian-21, which has been in space since 2021, had used most of its fuel in 2022 when it towed a defunct Beidou-2 navigation satellite to a graveyard orbit to reduce space debris. Now, its newer companion seems to have brought it back to life.
“This is a historic achievement if confirmed,” said Dr. Liu Yang, a Chinese aerospace expert. “In-orbit refueling changes everything. It means satellites do not need replacement every time they run out of fuel. People can repair them, refuel them, and reuse them.
COMSPOC shared updates on social media, explaining that between July 2 and July 6, their optical sensors showed the two satellites “appeared visually merged.” The company added, “Given the prolonged rendezvous and proximity operations, SJ-21 and SJ-25 may have docked.”
Throughout June and July, COMSPOC tracked multiple close approaches between the satellites. The first occurred on June 13 when they came within one kilometer of each other and stayed in position for about 90 minutes.
A second close approach was observed on June 30, and on July 2, s2a Systems noted the two objects “came closer again today and can no longer be separated by our instrument since about 11:00 UTC (7 p.m. Beijing time).”
Two U.S. military surveillance satellites, USA 270 and USA 271, were also nearby during these operations, monitoring the situation closely.
The importance of this goes beyond just refueling. Experts believe it opens the door to a future where people can maintain and upgrade satellites in orbit, reduce space debris, and save billions in launch costs. It could also play a role in deep space missions, such as sending humans to Mars.
Markus Steffen from s2a Systems said, “This isn’t just about satellites. It is about building infrastructure in space. Imagine spacecraft refueling stations orbiting Earth. This marks the first step toward that reality.”
NASA and DARPA previously tested autonomous docking and refueling in low Earth orbit. They used the Orbital Express mission in 2007. However, no one has performed these operations in geostationary orbit. Conditions there present far greater challenges.
Shijian-25 reportedly used robotic arms to attach to Shijian-21 and transfer fuel. The Shanghai Academy of Spaceflight Technology designed Shijian-25 and earlier stated that it built the satellite to test “on-orbit refueling capabilities and life-extension operations.”
In 2022, Shijian-21 was already making headlines for towing an old satellite out of the way to prevent collisions in crowded orbital paths. But that operation drained most of its fuel, and experts questioned whether anyone could salvage it. Now it appears China has given it a second life.
Dr. Liu noted, “This shows China is becoming a leader in space servicing technology. They are pushing the limits of what’s possible.”
Confirmation of refuelling will depend on official statements from the China National Space Administration. It may also depend on further analysis from international tracking organisations. But the evidence so far points to a major breakthrough.
“This could change how we think about satellites,” Steffen added. “As a result, no longer disposable, they could become long-term assets that we upgrade and maintain like cars or aeroplanes.”
