Keeping space safe: EU celebrates ten years of EU Space Surveillance and Tracking activities

A decade ago, the EU Space Surveillance and Tracking capability – or EU SST – was established. Let’s see how important it is to keep track of satellites and space debris, and what the EU has achieved in this domain. 

The EU Space Surveillance and Tracking (SST) system aims to avoid collisions between two satellites or a satellite and space debris. It also follows the re-entry of a satellite into Earth's atmosphere to avoid potential collisions with airplanes for example. And these operational services – available 24/7 – go hand in hand with research. 

EU SST was set up to protect Copernicus and Galileo satellites, but also public and private satellites of EU Member States. The number of satellites launched into space is constantly increasing. Before 2012, around 120 were put into orbit every year. In 2013, that number rose to 210, in 2014 to 240. The last five years saw an exponential increase, leading to 2,917 satellites in 2023. The number of debris – which can also have a big impact, even if the particle is very small – will also continue to increase. Without an SST system, access to space would no longer be possible. This would mean no more global navigation satellite system, no more climate monitoring, no more use of space technology for farming, etc. 

So, in 2014, the EU established the SST system as a pilot project with five Member States which was a big achievement. In the beginning, the EU and EU SST were the Cassandra of space activities! It was difficult to sell the programme: The EU was not selling dreams – it was talking about catastrophes. So, it had to explain reality and demonstrate the problem of collisions and their possible domino effect. 

Also, an EU SST system needs radars, telescopes and lasers – or 'assets' – all over the world to follow satellites closely. Although the idea was to provide an EU service, it was decided to rely on the Member States' existing assets to reduce costs and avoid unnecessary duplication. 

It's also difficult to exchange and merge data from these different sources, as you need the same quality and measurement systems, so mechanisms were set up to make this possible. 

Another challenge was that radars are military assets, so the EU had to gain the trust of military actors and involve them in the EU SST governance. 

And that governance is quite complex: while Member States have the assets and know-how, the Commission needs to oversee the whole system. Recently, it also started steering the development of an EU flagship programme: in 2021 the EU SST system became part of the EU Space Programme. 

The EU SST system is now following more than 500 satellites around the clock. It relies on more than 50 assets, not only in Europe, but positioned around the world, like in Australia, Africa, South America or Japan. 

The number of Member States that joined EU SST has risen to 15, and the collision avoidance service is now open also to non-EU satellite operators, including Norway, the US, Canada, Australia, Japan, Israel and Egypt. In addition, a catalogue has been developed to follow all the satellites and most of the debris above 10cm. 

At EU level, DG DEFIS together with the EU SST members established the European Industry and Start-up Forum (EISF) in 2021 to build an 'industry ecosystem', to gather all stakeholders and to boost the development of that community. In this way, industry can be more directly involved in research and technological developments rather than only being part of government research programmes. 

The services provided by EU SST 

DG DEFIS is currently looking into developing a space-based surveillance system, or SBSS which means studying space from space itself, not from Earth. An example of an SBSS application could be satellites used to detect and track debris. 

The use of AI is also being explored which could be useful for modelling and calculations, for example to avoid collisions within big satellite constellations. 

But space surveillance and tracking is only part of a bigger system: space traffic management, comparable in a way to air traffic management. And to properly manage space traffic, some developments are still needed. The rules of the road need to be determined for example: when satellites are on a collision course, which one has to give way? The oldest, the newest? The biggest or smallest? The civilian or military one? A regulatory system that harmonises rules on safety, sustainability, resilience and the environment in space needs to be set up, too. DG DEFIS are currently working on such a space law. And finally, DG DEFIS is pushing for the development of a similar system at international level with its main space traffic partners. 

Background 

EU SST is a subcomponent of the Space Situational Awareness (SSA) component of the EU Space Programme. It safeguards space assets, especially EU Space Programme satellites such as Galileo, EGNOS, Copernicus, GOVSATCOM and in the future IRIS², along with the space assets of EU Member States and other space operators.  

EU SST uses a network of ground-based sensors capable of surveying and tracking space objects and processing capabilities aimed at improving, operating, and providing data, information and services on space objects orbiting the Earth. This helps to mitigate the risk of a collision between space assets and other spacecraft and debris, in-orbit fragmentations and uncontrolled re-entries of space objects into the Earth’s atmosphere. 

More information 

• Regulation (EU) 2021/696
• EU Space Surveillance and Tracking - European Commission
• EU SST – EU Space Surveillance and Tracking