The UK’s military and spy agencies are working with civilian academics to develop new ways to spot snooping by foreign satellites, researchers have revealed.

The US, China and Russia have spy satellites as well as counter-surveillance satellite and spacecraft programmes that can spy on other states’ satellites and observe others spying on theirs.

For instance, the US has a space plane – the Boeing X-37B – which can stay in orbit for several years and is thought to be able to approach other satellites and eavesdrop on their electromagnetic (EM) emissions. China has a similar craft and Russia has satellites to perform the same function.

“They fly close, have a good look at what the other satellites look like, monitor any EM like radio transmissions, basically just trying to figure out the purpose of anything else in orbit,” says astrophysicist Mark Norris at the University of Lancashire, UK. “[The UK has] a big capability gap there because it’s quite expensive to have something capable of significantly changing its orbit to allow it to approach other satellites.”

Norris says he is aware of a desire from UK government intelligence agencies to discuss how industry, academics and even research observatories could help plug that gap and provide a sovereign UK capability, in particular because of concern over how reliant the UK has been on assistance from the US.

“There are people with ideas for small, relatively cheap inspection satellites. There are also people like myself who have ideas for things you can do from the ground, a lot more cheaply,” says Norris. “Ground-based observations give you the ability to watch a lot of these suspect objects at once, to help you figure out whether they are a threat against our own space infrastructure.”

Norris wouldn’t describe the techniques that might be possible in detail, but says ground telescopes could garner some structural information about an adversary craft just from images or even the wavelength of reflected light. This could reveal information about its composition, or the presence and size of particular components such as solar panels or antennae for example.

“There are things we think we can do from the ground that will get you 90 per cent of the way there. Not as good as if you’re in orbit, but it could certainly help you figure out [whether] the structure of this satellite does not match its claimed purpose,” says Norris.

The UK’s space surveillance and protection capabilities are managed by the National Space Operations Centre, a partnership between the UK Space Agency, UK Space Command and national weather service the Met Office. But with an annual budget of around £20 million, it has limited capabilities and essentially just collects observations from various sources in order to piece together an image of what is going on in space.

“They would go and hoover up observations and then try and do an analysis of it. And my own gut feeling is if you can’t control the quality of your data, all you do is produce crap out the other end,” says astronomer Don Pollacco at the University of Warwick, UK. “So, now there’s a push to get their own sovereign capability.”

In a statement, a spokesperson for the Ministry of Defence said: “The National Space Operations Centre (NSpOC) makes space safer and more secure, supporting international security and defence while helping to grow a strong domestic space sector. Since its launch, NSpOC has monitored the uncontrolled re-entry of over 1350 objects from space, issued 45,000 collision alerts to UK-licensed satellite operators, monitored 11 satellite break-up events and played a major role in international space hazard response.”

Snooping on the electronic emissions from satellites was easy in previous decades, says Pollacco, as they tended to broadcast in a wide cone that could be intercepted on the surface of Earth, even vast distances from the intended recipient. But now satellites tend to broadcast in narrower, more focused beams that mean the easiest way to intercept messages is to drift near them in space.

However, even for nations with a space plane, this approach has limitations, like only being able to target one object at a time. “So, we’ve been trying to think ahead as to what that situation will be like in a decade,” says Pollacco, if adversaries are able to launch many satellites into orbit. “Being able to even know that it’s been launched would be difficult and knowing what it’s trying to do [would be] even more difficult.”

Part of Pollacco’s work, initially designed for civilian monitoring of satellites for logistical purposes, involves running data on reflected light from satellites through AI models to identify them. “They’ve all got their own signatures,” he says.

Pollacco is also working on the Digital Telescope project, which uses an array of small telescopes to monitor a vast area of the sky at once. The project is funded by the European Research Council and will have scientific uses for observing phenomena such as supernovae. But it also has military and intelligence applications.

“The military are on to this,” says Pollacco, “and they offered an opportunity to make [something similar] for them. Anyone sneaking around to take pictures of your spacecraft, we see them.” The Digital Telescope will be able to capture images of satellites every 10 seconds with a resolution of around 10 centimetres. “It’s transformational,” he says.

James Blake at the University of Warwick says some academics working on satellite observation for civilian purposes already supply data on what they see to the UK government, but any groups taking money from intelligence agencies wouldn’t be able to speak freely about it.

“It’s quite complex to do, but we’re slowly getting better at inferring what these objects could be doing based on purely the light that we’re receiving in the telescope,” says Blake. “In this field, I think a lot of the funding is now coming from the more defence-related routes. It’s not something that I’m particularly happy about. I would much rather be working with the research councils.”

Defence funding can come with problems, such as not being able to publish research because of its potential impact on national security, says Blake. “It’s a very murky pool.”

Blake says observers on the ground are seeing more activity by nefarious satellites. “We’re starting to see a lot of behaviour that previously wasn’t really known to take place, or assumed to be plausible,” he says. “This can range from anything from a flyby to quite intimate inspection going on.”

Sometimes these manoeuvres are so complex that they can use up a satellite’s fuel reservoir in a single move. The intention may be purely to demonstrate the nation’s capabilities, says Blake, but such moves are risky.

“New spacefaring nations are, of course, going to launch these fabulous new satellites that they’ve been able to develop with new technology and they’re going to do things that are quite wasteful or reckless, such as this,” he says. “And the consequences are quite bad sometimes: you can create thousands of pieces of debris if you’re not careful.”