'Fast movers': Chinese satellites zoom around for inspections—or interference

Is China building out a satellite network in geosynchronous Earth orbit while deploying a fleet of robot guardians to patrol them?

In his final appearance before Congress as assistant defense secretary for space policy, on May 1, John Plumb appeared to suggest as much. “China has developed robotic satellites that…can be used for military purposes like grappling a satellite,” Plumb said.

It is clear that China sees the space domain as the “ultimate high ground” for competition back on Earth, reinforced by its recent reorganization of the Strategic Support Force and creation of a new Aerospace Force that reports directly to the supreme Central Military Commission. This vision is backed by more aggressive rhetoric in recent years.

In a moment of candor at the annual national congresses in Beijing, the former general director of China’s lunar exploration missions, Ye Peijian, asserted, “The cosmos is an ocean, the Moon is the Diaoyu Islands, Mars is Huangyan Island [Scarborough Shoal]. If we can go, but don’t go, future generations would condemn us. Once others are there, once others have occupied, no matter how much you wanted to go you couldn’t.”

Ye’s comment underscores how China sees the geostrategic nature of space, which is vast and yet subject to scarcity constraints. This is especially true in the geosynchronous belt, where orbital slots over densely populated areas are more valuable than those over sparsely populated oceans. And though Beijing is eager to stake its claims in orbital real estate, it also wants to show off capabilities and set the terms of debate over spacefaring norms and regulations.

This has been backed by a massive increase in space activities. China has launched more than 400 satellites in the past two years in a campaign to develop a global reconnaissance-strike complex on par with the United States. As part of this effort, in late 2023, China launched a Yaogan satellite to geostationary orbit for the first time, making it China’s largest remote sensing satellite in the GEO belt. It joined a growing constellation of high-capacity communications and electronic intelligence satellites in GEO, including three smaller Gaofen electro-optical satellites and the Ludi Tance-4 synthetic aperture radar satellite launched in August 2023—the only SAR satellite by any nation to be placed in the GEO belt. Of special note, it was placed at an unusually high inclination for a GEO satellite, allowing it to scan across the Indian Ocean and much of Asia from its orbital slot while panning north and south over the course of a day.

These rapid launches are giving China robust infrastructure for intelligence, surveillance, reconnaissance, and communications. China “has rapidly advanced in space in a way that few people can appreciate,” said Maj. Gen. Greg Gagnon, deputy chief of space operations for intelligence, last week.

‘Fast movers’

Yet there is another aspect of China’s increased space activity that is adding to the rapidly shifting strategic dynamic in orbit: the activities of a series of co-orbital inspectors and robotic manipulator satellites over the last few years, which point to a larger pattern of planning to observe and even disrupt other nations’ space activities. 

Among China’s new fleet of satellites are several “fast movers”: satellites that roam the GEO belt, drifting back and forth among the “stationary” ones. Like ship tenders, they can help assess and repair malfunctioning satellites. For instance, debris mitigation may have been the primary mission for the Chinese satellite Shijian-21, which in 2021 grappled a derelict Beidou satellite and boosted its orbit up 3,000 km, into an unusually high and eccentric graveyard orbit before returning to the GEO belt. But these “tender” spacecraft could also be used maliciously against other nations’ satellites.

In 2018, Tongxin Jishu Shiyan-3 raised eyebrows when it became apparent that the satellite was not alone. Its apogee kick motor, which had circularized its orbit, retained enough fuel to enter GEO itself. The motor and TJS-3 conducted a series of “rendezvous and proximity operations” maneuvers in an apparent checkout phase over the first few weeks in orbit.

TJS-3 displayed new tactics when it left to execute its primary mission. TJS-3 thrusted away from its original position, taking advantage of the daytime terminator phase (the period when ground-based telescopes are most likely to lose track of it). Its motor had maneuvered next to the primary satellite so that any observer who reacquired it would see the booster sitting where the satellite was; in effect, a decoy maneuver. This could allow TJS-3 a few days of unmonitored activity, where it might be able to get a jump on any target satellite it was heading towards. This became a pattern, and possibly standard operating procedure, when Shijian-21 performed a similar feint and scoot using its apogee kick motor shortly after it arrived in orbit in 2021.

Such capabilities can easily be repurposed to gather intelligence on foreign satellites, or even to grapple with and neutralize these satellites. Shortly after it completed its checkout phase, China's Shijian-17 satellite began a series of approaches to various satellites located in the GEO belt, including French, Russian, and Indonesian communications satellites. Likewise, according to Satellite Dashboard data, in 2021, Shiyan-12-01 and Shiyan-12-02 also approached several foreign communications satellites shortly after they arrived in GEO.

But China has also found itself on the receiving end of such tactics. Russia, known for its aggressive earthbound intelligence collection techniques, appears to be using its satellites to gather intelligence on those of other nations. Russia’s GEO inspector satellites of the Luch/Olymp series are believed to also be signals intelligence satellites, for instance, visiting and staying near Western communications satellites for extended periods of surveillance.

This played out in a previously unreported activity between Russian and Chinese satellites. Weeks after arriving in orbit in February 2019, China’s TJS-3 and its apogee kick motor were approached by Russia’s first Luch/Olymp, which came within 30 km, according to tracking data provided by Satellite Dashboard. While Luch/Olymp had previously approached Chinese communications satellites, this appears to have been the first red-on-red approach of one maneuvering satellite by another.

Russia is not the only party interested in the PRC’s maneuvering assets in space. The U.S. not only shadows PRC satellites, but pioneered many of these tactics with its own Geosynchronous Space Situational Awareness Program (GSSAP) series of inspector satellites, begun in 2014. In 2021, for instance, GSSAP-4 approached the advanced communications satellite Shijian-20 (SJ-20) to the chagrin of PRC satellite operators and observers.

In reaction to these challenges, PRC satellites appear to have developed active evasive maneuvers. Shortly after reaching orbit in late 2021, Shiyan-12-01 and -02 were approached by a U.S. GSSAP satellite, at which point the pair “took off in opposite directions,” and one even took up an advantageous position to image the GSSAP satellite itself. Similar behavior occurred when GSSAP-4 approached SJ-20. As GSSAP closed in on SJ-20, the satellite increased distance to hinder any attempt by GSSAP to gain information about its capabilities.

China has grown openly alarmed at these trends. Researchers in China’s space community have also called the U.S. GSSAP satellites “a serious threat to high value assets in GEO.” In turn, despite a closer relationship between the two, PLA commentators have worried that Russian RPO satellites could be stealthy anti-satellite platforms able to “attack with directional explosives, or use lasers, microwaves, or other means to destroy or render ineffective target satellites.” This concern has been buttressed by allegations this last week by Mallory Stewart, assistant secretary for the Bureau of Arms Control, Deterrence, and Stability, that “Russia may be considering the incorporation of nuclear weapons into its counterspace programs.”

With little progress toward a negotiated modus vivendi in space, these interactions and tactics are inadvertently forming the basis of spacefaring norms and behaviors through unchallenged precedent. As increasingly capable multi-role RPO satellites populate high orbit, the three nations that have them—the United States, Russia, and China—are learning how to behave or misbehave in the heavens through trial and error, creating a volatile environment where mistakes could lead to conflict or disaster.

David D. Chen is a Senior Analyst for BluePath Labs. He focuses on aerospace, cyber, and cross-domain emerging technologies and China’s military modernization.