Kammy Brun / Nov 2026
Image: Shutterstock
More and more of Europe’s critical infrastructure is now in orbit. Satellites big and small underpin communications, navigation, defence, banking, emergency response, even farming. And the importance of this infrastructure will only grow. This was one of the central themes of the International Space Summit in Paris on 9 and 10 September, where European governments promised to make Europe a more competitive, autonomous space power. Their declaration called for stronger European industry, greater institutional demand, more resilient supply chains, and less dependence on non-European technology and infrastructure. Europe will need to develop its sovereign launch capacity, but the age of European made satellites and payloads has now given way to one in which vast constellations predominate.
Building satellites and sending them into space is only half the battle. The satellite operators must also know what’s going on around those satellites. There are 18,000 active satellites in Low Earth Orbit (LEO), 10,000 of them owned by SpaceX, and they all share that region with spent rocket stages, fragments and other debris. Military spacecraft, meanwhile, are growing in sophistication. Some can now approach, inspect and follow other satellites, and are doing so. Operators, therefore, need to know more than where some object ought to be. They also have to know where the object is, how it’s moving and what it’s likely to be doing.
Hence Space Situational Awareness, or SSA. Much of our knowledge of activity in orbit comes from the ground, thanks to radars and telescopes, which help operators to track objects and predict close approaches. Though these systems are vital, they have their limits. A ground sensor, for instance, can only observe the part of its sky within its reach; clouds and the atmosphere can restrict observations; an object may pass through a sensor’s field of vision only briefly; and so on. Ground-based SSA needs support.
And this is where Space-Based SSA (SBSSA) comes into play. It involves putting cameras and other sensors on satellites, thereby giving operators new viewing angles and the ability to see things that are difficult to see from Earth. As a complement to ground-based sensors, SBSSA produces a fuller, richer, more timely picture of the orbital environment. Crucial to this is Non-Earth Imaging (NEI): unlike most satellite cameras, an NEI payload looks outwards, towards other objects, rather than down to Earth. The quality of intelligence this produces is precisely what operators need as orbit grows more and more congested and contested.
Nor is this merely a European problem. The UN Committee on the Peaceful Uses of Outer Space (COPUS) now has an Expert Group on Space Situational Awareness, intended to improve the sharing of SSA information, make data easier to use across different systems and strengthen international cooperation. Its work reflects the fact that as orbit becomes more crowded, knowing what is there, and what it is doing, becomes more important for everyone involved in space – especially those in defence. Indeed, the United States Space Command recently called for a ‘target-quality track’ approach to space-domain awareness: military operators need information that is precise, timely and detailed enough to enable high-quality decision-making during a conflict. Having a general catalogue of objects is not sufficient to help decision-makers take action when spacecraft can increasingly manoeuvre, approach important assets or target forces on Earth.
SBSSA will need to grow as an area so a large number of optical payloads can observe the same objects with greater frequency and from different angles. The result would be a higher revisit rate – in other words, less time between one observation of an object and the next. The more observations of an object, the easier it is to track that object, detect a manoeuvre and identify any patterns. Moreover, a distributed network is more resilient. If one sensor fails, the others will continue to work. More important still, a constellation of SBSSA payloads can reduce the time for which an operator loses sight of the object it is tracking. This matters most in military operations, where a gap in observation may also mean a gap in understanding. Yet few operational SBSSA constellations are in orbit today.
This obliges optical payload manufacturers to build small, light payloads that are optimised for cost and power needs and place little strain on the host satellite. Ideally, the payload should be easy to integrate with different spacecraft and able to process information on board so that terabytes of data don’t have to be sent down to Earth first to be crunched, analysed and made actionable. Fortunately for Europe, there are already companies that build these kinds of payloads. Its task now is to build on that strength.
That will require greater collaboration between the satellite operators, the payload developers, data companies, and governments. Governments need to communicate their needs; industry must then respond. SSA, space-based and ground, must be combined to produce the richest intelligence possible. The Paris declaration goes further in calling for coordinated public procurement and advance market commitments to generate demand for European space services, while strengthening European industry, SMEs and start-ups. It also calls for closer cooperation between the EU, ESA, Member States and EUSPA, with clearer responsibilities for each and less duplication between all. If Europe can bring such a scenario about, it will be able to protect its military communications, identify possible threats and understand events without depending on information supplied by others. In other words, it will move one step closer to achieving its long-stated goal of strategic autonomy – something that can’t come soon enough.
Ground sensors still matter. Indeed, they’re essential. But as orbit gets more crowded, as geopolitical tensions grow, and as satellites get more sophisticated, it’s vital that Europe’s satellites develop, if you like, eyes of their own. Widespread networks of hosted optical payloads can deliver the timely, frequent, accurate observations the continent needs to know what is going on in orbit, and so protect the satellites on which, as I have already suggested, modern life depends.
The argument made in Paris was broader than SSA alone. Europe wants sovereign launch, communications, navigation, Earth observation and resilient supply chains. It also wants European demand to support European industry, and public institutions to work together more coherently. But SSA belongs in that list for a reason. A space power that cannot see clearly what is happening around its own satellites is not fully autonomous. Europe already has many of the pieces. It now has to join them up.
