In the grand scheme of the cosmos, the space surrounding our planet is getting crowded. With over 20,000 satellites expected to launch within the next decade, our near-space environment, especially the Low Earth Orbit (LEO), is set to face an unprecedented space traffic jam ––but unlike with traffic jams on Earth, an accident up there could be catastrophic.
Take the company SpaceX alone, which since 2019 has launched around 4000 satellites into LEO — over half of all active satellites operating in space right now. Professor Hugh Lewis of the Astronautics Research Group at the University of Southampton, keeps a close eye on the massive constellation of satellites.
He estimated that in April of this year, SpaceX Starlink satellites had to make a cumulative 45,000 manoeuvres to avoid crashing into other satellites.
At least two more companies, OneWeb and Amazon, are planning to put similar mega-constellations into orbit.
This congestion is not merely an inconvenience—it creates a significant amount of space debris, a problem that's escalating at an alarming rate.
The European Space Agency (ESA) — an intergovernmental organisation composed of 22 member states, mostly from the EU — defines space debris or 'space junk' as all non-functional, human-made objects, including fragments and elements thereof, in Earth orbit or re-entering the atmosphere.
Space debris can include defunct satellites, spent rocket stages, fragments from disintegration, erosion, and collisions, and even tiny flecks of paint. Objects from past space missions can also become debris if they are left in orbits around the Earth.
According to the Directorate General for Defence Industry and Space (DG DEFIS), there are over 1 million debris items larger than 1cm currently orbiting Earth.
In addition to the larger pieces of space debris, an estimated million objects range from 1 to 10 cm in size, and a staggering 130 million fragments are smaller than 1 cm. The rising number of these smaller particles is particularly concerning as larger objects collide at tremendous orbital speeds, generating clouds of fragments.
While tracking is regular for larger debris fragments over 10 cm in size, trajectories of smaller pieces remain mostly unknown, and the collisions they can instigate occur entirely without warning. Debris experts express grave concern about potential encounters between two large defunct bodies—like dead satellites or used rocket stages.
A worrisome instance of such a close approach occurred on 27 January this year, between a decades-old Russian rocket upper stage and a long-defunct Russian satellite. With neither object able to manoeuvre, space traffic guards could do nothing more than hope the two would avoid collision.
Fortunately, they did—by a mere 6 metres. This incident, described as a close call "worst-case scenario," could have created thousands of hazardous debris fragments destined to remain in orbit for centuries, posing threats to everything in their path.
While some of this debris may eventually re-enter Earth's atmosphere and disintegrate, much of it could remain in orbit for hundreds, even thousands of years.
The repercussions of this space debris are far-reaching. It can cause catastrophic damage by colliding with operational satellites, creating even more fragments and exacerbating the issue.
In extreme scenarios, if debris strikes our navigation satellites, it could disrupt the GPS services on our phones, impede aeroplane landings, and even interrupt bank transactions.
The threat is not just theoretical. In 2016, a millimetre-size particle in orbit struck the European Copernicus Sentinel-1A satellite, damaging one of its solar panels. Luckily, this did not affect the satellite's overall performance, but it served as a stark warning of the irreversible damages that could be inflicted on our communication, navigation, and Earth Observation satellites by larger debris.
On February 25th 2021, the European Union Agency for the Space Programme (EUSPA) received a collision risk alert between GSAT0219 and an inert Ariane 4 upper stage launched in 1989. Thanks to the cooperation between the EU Space Surveillance and Tracking (EU SST) and EUSPA, the risk was monitored and managed successfully.
In practice, the process of detecting a potential collision and evasive manoeuvres being performed consists of two steps.
EU SST is constantly analysing the available data on trajectories of satellites and debris, and their orbital parameters to determine if any risks — and potential severity — of collisions exist.
If a potential collision is determined, the Front Desk, currently operated by the European Union Satellite Centre (SATCEN), generates and issues collision avoidance alerts to "spacecraft owners, operators, and other relevant stakeholders to notify them of the
potential collision and provide necessary recommendations for evasive manoeuvres or other
actions to avoid the collision," EUSPA Executive Director Rodrigo da Costa writes to EUobserver.
After simulating the chance of success of moving the satellite to avoid collision — and making sure it won't bump into anything else after moving — the evasive manoeuvres then consist of using the onboard propulsion systems to speed up or slow down the satellite, or move it closer or further away from the Earth in its orbit.
To tackle the issue of space debris and congestion, the European Commission last year proposed an integrated approach to Space Traffic Management (EU STM), underlining the long-term viability of space activities by ensuring space remains a safe, sustainable, and secure environment.
The commission approach calls for the creation of STM legislation, mirroring existing EU regulations for air traffic management.
On top of those rules, EU SST currently "provides services based mainly on the United States (US) catalogue of space objects, complementing this catalogue increasingly with its own data and national catalogues," the commission report states — while also expressing the need to increase the performance of its own SST "operational capabilities."
"It is of a geostrategic question to be able to monitor autonomously space and enhance our collective situational awareness of threats to European or national Space assets," remarked Commissioner for Internal Market Thierry Breton during the European Space Conference in 2023.
In the report, the commission seeks both to expand the EU's technical capabilities in sensing space debris, and to enhance the coverage of the sky with EU-controlled assets located outside the European continent, as most current sensors are located within the EU, thus limiting the field of vision.
Eventually, the EU's STM approach should contribute to a global STM that should be managed at an international level. "As part of the EU STM approach, the Union will seek to foster the discussion on STM in the relevant UN fora in particular the Committee on the Peaceful Use of Outer Space (COPUOS), but also in the Conference of Disarmament with the objective to table a discussion at the UN General Assembly," the commission report states.
The EU's reliance on the EU SST Partnership, the main operational pillar of STM, has been instrumental in providing guidance on collision avoidance.This partnership operates a network of ground-based sensors capable of surveying and tracking space objects, along with processing capabilities that provide data, information, and services on these objects. As of now, EU SST provides collision avoidance services to around 400 satellites in various Earth orbits.
As part of its expanded role in the Union Space Programme, EUSPA took responsibility for the SST service provision Front Desk as of 3 July, 2023. "The EU SST Front Desk is a key interface for the delivery of SST information and services, including activities related to user coordination, service performance," says EUSPA Executive Director, Rodrigo da Costa.
The transfer of the Front Desk from SATCEN to EUSPA is a significant step, da Costa says. But it's also just the beginning. "As the demands and challenges of space operations increase, EUSPA is ready to expand its capabilities, adapt to emerging technologies, and play a crucial role in ensuring the long-term viability of outer space activities," he tells EUobserver.
The transfer of responsibility for the Front Desk from the European Satellite Centre (SatCen) to EUSPA aims to ensure a smooth transition and service continuity. The new premises of the EU SST Front Desk are located at EUSPA's Galileo Security Monitoring Centre (GSMC) in San Martín de la Vega, Madrid, Spain.
EUSPA's expanded competencies, including a crucial role in Space Situational Awareness (SSA) and SST, are vital for safeguarding space infrastructure. The agency will also contribute to the EU's approach to Space Traffic Management, ensuring safe and sustainable use of space while preserving the competitiveness of the EU space industry.
With these developments, the EU continues to take significant strides towards addressing the looming threat of space debris. And by pushing for better and more effective regulation of the creation — and responsibility for — space debris, the EU might be setting standards to keep space safe well into the future.
This article was commissioned by the European Union Agency for the Space Programme (EUSPA), and produced by EUobserver as partner content.
This article was commissioned by the European Union Agency for the Space Programme (EUSPA), and produced by EUobserver as partner content.