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A mysterious Russian satellite and a confidential US military satellite appear to be engaged in a cat-and-mouse chase through space.
The Russian spacecraft, called Kosmos-2558, was launched in the same orbital plane as the US satellite, called USA-326, in August 2022 and has regularly passed close to the American spacecraft since then.
Kosmos-2558’s behavior and lack of a formal explanation from Russia has led space observers to believe that the probe is stalking USA-326. It’s at least the third satellite launched by Russia that appears to be an “inspector,” a spacecraft that aims to collect data from up close on another satellite.
The image below shows how much detail a surveyor satellite might be able to capture when photographing its target. A Maxar satellite, which usually photographs Earth, snapped this photo while flying over a discarded piece of an orbiting Japanese rocket:
“It’s just amazing,” Jonathan McDowell, a Harvard astrophysicist, told Insider of Maxar’s image. “And this is for a satellite that isn’t designed to look at other satellites. It was designed to look at the Earth.”
If Kosmos-2558 is the inspector it appears to be, designed specifically to track down and likely collect data on USA-326, then it’s probably getting even better pictures.
Spacecraft have been spying on each other for decades. All you have to do is launch your satellite into a higher orbit than the satellites you want to observe. But Russia appears to be trying a new method of pursuing particular targets, and it’s not clear why.
“This is really irresponsible behavior,” General James H. Dickinson, commander of the US Space Command, told NBC News after Russia launched Kosmos-2558. “We see it in a similar orbit as one of our high-value assets to the US government.”
The Pentagon has said that USA-326 is intended to support “overhead reconnaissance” – a spy satellite program to gather information by observing the Earth.
Dickinson added that the United States will continue to track the Russian spacecraft.
How one satellite can track another
The two satellites are orbiting the Earth in the same plane, but at different speeds, allowing Kosmos-2558 to pass smoothly under its US target.
“If you imagine two athletes running around a track on slightly different lanes of the track, and one is faster than the other, every now and then one will spin the other and pass by,” McDowell explained.
Each ride could be an opportunity to take a photo.
According to McDowell’s observations, Kosmos-2558 made four flybys of USA-326 in March. The Russian satellite usually passes within about 50 kilometers (31 miles) of its American target, not close enough to risk a collision, but close enough to likely get detailed images.
“I see him as nosy rather than aggressive,” McDowell said.
Russia appears to be experimenting with new space stalking technology
Russia has already done it.
Another Kosmos satellite exhibited “stalking” behavior after its launch in 2014, but it was chasing its own rocket stage, not an adversary spacecraft, according to Anatoly Zak, a reporter who covers Russia’s space program and manages RussianSpaceWeb.com.
Then, in 2020, a US Space Force general reported that two mysterious Russian satellites were tailing a US spy satellite.
“It appears to be a program that they’re experimenting with this technology,” McDowell said.
The US satellite just moved a little higher
In the latest development of this orbital hide-and-seek game, the U.S. satellite leapt to a higher orbit, climbing farther just before Kosmos-2558 passed nearby again on April 7, according to hobby satellite tracker Nico Janssen.
The Russian satellite was due to pass its US military target at a distance of about 31 kilometers on April 7, Janssen calculated. Instead, the most he could get was 45 kilometers.
This may have been a maneuver conducted by the United States to evade the close approach of the Russian satellite, Zak said. But it’s unclear whether the American satellite was escaping.
“It would have been pointless, since the Kosmos satellite can also raise its altitude again if it wishes,” Janssen told Insider in an email.
McDowell agrees.
“It’s *possible* that this was an evasive burn but not *likely* in my current opinion,” she said in a follow-up email.
Instead, Janssen thinks the US satellite was just performing a routine push to compensate for recently lost altitude to solar activity. Flares on the sun have sent charged particles to Earth, which can push satellites into lower orbits.
Between the sun and orbital spies, “satellites are very vulnerable,” Janssen said.
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