A common refrain in the space policy community is that ‘space is contested, congested and competitive’. The ‘contested’ aspect was demonstrated recently when two Russian intelligence –collection satellites closed in on, and trailed, a top-secret US KH-11 reconnaissance satellite.

It’s like something out of a technothriller novel, but it’s not fiction. Russia launched the Cosmos-2542 satellite on 25 November 2019 from its spaceport in Plesetsk using a Soyuz-2-1V rocket. The satellite is classed as a 14F150 Napryazhenie geodetic satellite and is part of Moscow’s ‘Nivelir-ZU’ (14K167) project for undertaking geodetic studies of earth’s gravitational field to enhance guidance of long-range ballistic missiles. The satellite is designed as a multi-purpose system that can also perform a ‘satellite inspector’ role. The Russian defence ministry acknowledged this as far back as August 2017.

Let’s consider the ‘orbitology’ of the event. According to the website Russian Spaceweb, Cosmos-2542 is orbiting with an orbital inclination (it’s tilt relative to the earth’s equator) of 97 degrees. That means it entered a polar orbit, with a perigee (the lowest point in its orbit) of 378 kilometres and an apogee (the highest point) of 922 kilometres.

On 6 December, Cosmos-2542 released a small subsatellite, Cosmos-2543, and on 21 January, the two Russian satellites began to alter their orbits to closely match the orbit of the US National Reconnaissance Office’s KH-11 spy satellite, which is designated ‘USA-245’. Two days later, the US decided to move USA-245 and now the US and Russian satellites are further apart, out to a distance of around 500 kilometres.

A key source on this event is amateur satellite tracker Michael Thompson. He notes that following the Russian manoeuvres on 21 January, Cosmos-2542 was able to keep USA-245 in constant view, when both satellites were in sunlight, at a distance of between 150 and 300 kilometres. That sounds a long way here on earth, but in space its close enough for valuable intelligence to be gathered, using optical and potentially electronic surveillance. Although the US moved its satellite, Thompson’s analysis suggests more close approaches could occur by late February, with the closest at less than 100 kilometres on 21 February (see here for a diagram).

Incidents like this aren’t uncommon. They’re called ‘rendezvous and proximity operations’, or RPOs, and all the major space powers have developed satellite-inspector capabilities that can undertake these tasks. The US’s X-37B reusable spaceplane is the most sophisticated vehicle for this type of mission, and its most recent assignment concluded in October 2019 after 780 days in orbit. China and Russia have both practised RPOs in geosynchronous orbit in recent years, and the US undertakes similar tasks.

Such activities can be a legitimate part of a nation’s ‘space domain awareness’ mission (the military version of civil space situational awareness). This is an essential task in both a contested and congested space domain—contested space requires early warning of potential counterspace threats, and congested space requires an understanding of the space environment to mitigate the risk posed by space debris.

So, what’s the significance of the Russian satellites’ activities?

While everyone does intelligence-gathering, this incident raises concerns about future major-power adversaries exploiting grey zone activities in orbit, either to gather intelligence or for more aggressive purposes.

Undertaking RPOs is going to be an essential requirement for orbital refuelling and repair missions, which will emerge as a lucrative commercial activity in the next decade. The ability to repair a satellite on orbit, or to de-orbit it to avoid a build-up of space debris, is a legitimate enterprise for would-be space startups, and will be an important element of a space-based economy. A commercial spacecraft will manoeuvre into close range with a target satellite, and then dock with it to carry out repairs or to refuel it. That sort of capability is going to become more commercially attractive to sustain the mega-constellations of thousands of satellites that will be deployed in low-earth orbit in the next decade.

For innocent commercial activity, this technology is highly desirable. It will allow dead satellites to be restored to operational use, generating profit for the company providing the service. But it will also lead to further development of spacecraft technology that can be applied for military purposes. And how does one distinguish an on-orbit servicing craft from a co-orbital anti-satellite weapon (ASAT)? Co-orbital ASATs would be equipped with electronic warfare capabilities, or a directed-energy weapon such as a high-powered microwave, to neutralise an adversary’s satellite in a counterspace attack at close range—precisely the type of event suggested by Cosmos-2542.

Let’s consider where that leads. A ‘soft kill’ in space warfare is infinitely preferable to a ‘hard kill’, which physically destroys a target satellite, creating clouds of space debris. China’s January 2007 ASAT test created about 40,000 pieces of space debris larger than a centimetre across, and up to two million fragments wider than a millimetre. Large-scale use of hard-kill ASATs could create enough space debris to dramatically boost the prospect of a ‘Kessler syndrome’ event that could deny humanity access to space for generations. It makes no sense to develop hard-kill ASATs.

The Russian RPOs against USA-245 with Cosmos 2542, and similar events in the past, reinforce the potential for an intelligence-collection technology to be applied for other purposes, and to further develop soft-kill co-orbital ASAT capabilities. Such technology could be hidden within intelligence collection, as part of space domain awareness, or even masked within entirely legitimate commercial activity.

The challenge of managing grey-zone activities in orbit is an issue that space policy, law and regulatory bodies must come to terms with. The University of Adelaide–led ‘Woomera manual’ and the ‘MILAMOS’ project led by Canada’s McGill University are moving in the right direction to deal with these issues, alongside international efforts within the UN Office for Outer Space Affairs. Building confidence and transparency between states about commercial companies undertaking activities that have national security implications would be a good step to avoiding suspicion and insecurity in the future.