In a major leap for space technology, China has reportedly become the firstcountry in the world to successfully refuel a satellite in orbit, anachievement that has significant implications for the future of spaceoperations and global strategic balance. According to multiple spacetracking agencies and Chinese media sources, two Chinesesatellites—Shijian-21 (SJ-21) and Shijian-25 (SJ-25)—executed a complexorbital maneuver in geostationary orbit (GEO), approximately 36,000kilometers above Earth. The operation, conducted between June and July2025, is believed to have included a successful autonomous docking followedby the transfer of hydrazine fuel, marking the world’s first confirmedsatellite-to-satellite refueling mission in such a high and sensitive orbit.
Shijian-25, launched in January 2025 aboard a Long March 3B rocket, wasspecifically designed for mission extension and refueling experiments. Itapproached SJ-21, a satellite that had run out of fuel in 2022 after aprevious orbital relocation mission. Satellite tracking firms such asCOMSPOC and s2a Systems closely monitored the operation and confirmed thatthe two spacecraft remained in contact for several days. During this time,their orbits merged, and optical observations indicated a close-proximityoperation consistent with docking and fluid transfer. Reportedly, SJ-25transferred approximately 142 kilograms of hydrazine to SJ-21, which isestimated to extend the satellite’s operational life by up to eight years.
This development is being hailed as a significant step forward for spacesustainability. Traditionally, once satellites run out of fuel, they areeither left to drift as space debris or deorbited. With in-orbit refuelingcapabilities, satellites can now have their lifespans extendedsignificantly, reducing the need for expensive replacement launches anddecreasing space congestion. From a technical standpoint, executing a fueltransfer in geostationary orbit is extremely challenging. It requiresprecise autonomous docking, accurate alignment in three-dimensional space,and secure handling of volatile propellant in zero gravity—all at tens ofthousands of kilometers from Earth.
While the scientific and commercial implications of this mission arepromising, the strategic and military dimensions are also under scrutiny.In-orbit refueling technology can also be applied to maneuvering militarysatellites, repositioning assets, or potentially even interfering with thesatellites of other nations. Western analysts and defense officials havenoted that China’s advancement in this area places it ahead of the UnitedStates, Japan, and other spacefaring nations. Though the U.S. had plannedsimilar missions—such as DARPA’s Orbital Express in 2007 and NASA’s OSAM-1(formerly Restore-L), which was canceled in 2024—none had achieved such ademonstration in GEO.
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The global reaction has been mixed. On one hand, space experts acknowledgethe impressive technical achievement, which sets a new benchmark forsatellite servicing and could pave the way for commercial satelliterefueling missions in the future. On the other hand, there is growingconcern about the dual-use nature of such capabilities, particularly in anincreasingly contested space environment. The operation by SJ-25 is beingclosely analyzed by U.S. Space Command and international observers, withcalls for clearer regulations and transparency in orbital servicingmissions.
As of now, China has not issued a detailed official statement confirmingthe technical specifics of the operation. However, the international spacecommunity, including independent observers, continues to monitordevelopments closely. If fully verified, this mission marks the beginningof a new era in space—one where satellites are no longer disposable butserviceable, refuelable, and capable of long-term operations. It alsosignals China’s growing leadership in high-tech space operations, settingthe stage for further advancements and geopolitical shifts in the spacedomain.