Dr Michael Hennessy Picard holds a PhD in Law from the University of Quebec in Montreal (Canada) and is a Lecturer in International Environmental Law at the University of Edinburgh (UK). He is working on the regulatory oversight of satellite re-entry, ablation and atmospheric pollution.
Can you explain the concept of “space debris” and what we can do to tackle it?
Michael Hennessy Picard: Space debris refers to all human-made space objects, including fragments and elements of non-functional space objects in Earth orbit or re-entering the atmosphere. It comprises all human-made objects in space, including fragments and parts of space structures in Earth’s orbit or re-entering the atmosphere that are no longer functional. This definition encompasses components and segments of decommissioned spacecraft, whether they are functional or not, as well as spent upper stages of rockets. Therefore, it isn’t limited to satellites but also encompasses rocket stages and similar objects. In essence, it includes a vast range of space objects.
By 2030, there may be 58,000 active satellites. The projection is primarily driven by advancements in satellite technology and the proliferation of small satellite constellations for global internet coverage. As space becomes more congested, the amount of debris in low Earth orbit is rising by about 3 to 5% each year. This not only endangers operational satellites and the International Space Station but also complicates future space missions.
So, the problem arises when space debris strikes another orbital object, causing the space debris to multiply until it potentially turns space into a junkyard. This risk, associated with collisions between space debris or functioning satellites, has been documented since 1978 in the famous publication by Kessler. According to his theory, we could reach a snowball effect of cascading debris, where each collision creates new pieces of junk that collide in ever-increasing numbers. If the Kessler syndrome were actually to happen, all missions would have to expect damage in certain areas of space.
Despite known risks of space debris, the term ‘Space Debris’ lacks a clear definition under the Outer Space Treaty. No binding laws require space actors to prevent additional pollution or debris buildup. Instead, there are guidelines or standards, what is known as soft law. These are not legally binding, but they serve as recommendations from space agencies such as NASA, the International Space Agency, the European Space Agency and other international bodies, including the UN Office for Outer Space Affairs.
These guidelines have to be individually implemented by states to become enforceable under national licensing regimes. Lately, the Commission has been drafting a Proposal for a EU regulation, clarifying common orbital traffic rules on collision avoidance manoeuvres.
How can we create laws to make a ‘circular economy’ in space like we try to do on Earth?
Michael Hennessy Picard: That’s a good question. Regarding the circular economy, international law can create incentives to shift from a linear economy, where satellites are manufactured in orbit and then disposed of in a linear manner. The circular economy rests on three pillars: The first pillar of the circular economy is protecting spacecraft, so extending the life expectancy of a satellite in the first place. The second pillar is to reuse and repair space objects. And the third pillar is to retrieve and recycle abundant objects. Although the concept of a circular space economy is still emerging, there are several soft laws and engineering guidelines that incorporate these pillars into models for space management.
I believe Europe is probably leading efforts to implement a circular space economy model. I am less familiar with Chinese regulations and incentives related to this, mainly because I have not had much exposure to their sources. However, it is important to monitor their progress since the Chinese space industry is rapidly growing, and understanding their sustainability efforts is crucial. Currently, traffic management and collision avoidance systems are being explored by the US and the European Space Agency. There are also incentives to develop standards, with some already in place.
For example, there’s an international docking system standard that encourages shared use of space systems via a common interface. By following this standard, any company can offer on-orbit servicing on space stations, including refurbishment and refuelling. This helps avoid early satellite decommissioning and promotes sustainable space practices.
To make space manufacturing and launches greener, what legal incentives or rules can encourage companies to use more eco-friendly ways of building spacecrafts?
Michael Hennessy Picard: The core issues are technology transfers, licensing and taxation. How can we motivate commercial actors to adopt more sustainable practices?
A key priority is to level the field of sustainable practice for small and medium-sized enterprise, which may lack the R&D to transition to state-of-the-art sustainable manufacturing. Here national space agencies, such as NASA and ESA, have a crucial role to play, since agency-backed contracts account for a significant proportion of space activities and can make use of a number of channels to support technology transfers. Agencies can steer open-source initiatives to release sustainable design technologies into the public domain through their technology transfer programs. This paves the way towards wider adoption of eco-friendly spacecraft technology.
Another approach is to integrate sustainability standards into the licensing process before a space actor is authorised to launch. For example, if a company wants to launch from a European country, they must meet requirements like using sustainable fuel, designing for an extended spacecraft lifespan, preparing contingency plans for accidents, and prioritising reuse over disposal.
These sustainability criteria can be embedded within the national licensing regime. If the draft EU regulation on space is passed, space operators will be required to evaluate their environmental footprint throughout the entire lifecycle of their space mission (from design and manufacturing to launch, operation, and disposal).
Finally, taxation can serve as an incentive. Taxation can be adjusted based on the materials, fuel, and design choices of space operators, such as lower taxes for using recyclable materials or sustainable fuels. This eco-modulation encourages the space industry to adopt environmentally friendly practices.
Is there a way to learn from and apply our understanding of sustainability principles related to Earth to space practices?
Michael Hennessy Picard: Earth teaches us an important principle from maritime law called the polluter pays principle. If an oil tanker causes pollution, its owner must cover the costs for damage to people and property, repair and ecosystem rehabilitation. Why not apply this principle to space? In 2023, the US already did so when they fined a US space operator $150,000 for failing to decommission a satellite properly. The satellite lacked enough fuel to be deorbited and became space junk. The operator had to pay a penalty for irresponsibly handling its space object. The polluter pays principle could be applied more broadly in space to fund space debris remediation missions.
Why are collaborations across diverse fields, such as engineering, ethics, economics, and law, crucial for finding comprehensive solutions to space sustainability and resource management?
Michael Hennessy Picard: In 2023, the UN University recognised space debris as a critical risk tipping point. What does this mean? Space debris can cause a snowballing effect that impacts society, the environment, and essential infrastructure like GPS, weather forecasting, disaster response, and communications, potentially leading to their loss. Since it’s a complex and cascading problem, addressing it requires collaboration across multiple fields, as no single discipline can solve the global issue of space debris alone. Engineers are needed to ensure mission longevity, while ethics help prioritise concerns.
For instance, shall we decide on a hierarchy of concerns and priorities, where scientific missions take precedence over commercial ones like 5G? Public debates involving civil society and elected officials must grapple with these questions. Additionally, U.N. policymakers must strengthen regulations to treat space as a shared environment rather than a dumping ground. In essence, diverse fields must work together to prevent space from becoming a tragedy of the commons. That’s the core challenge.
What is your ultimate wish for how humanity’s entire presence and activity in outer space evolves to be truly sustainable, equitable, and beneficial for generations to come?
Michael Hennessy Picard: Space is now regarded as an endless resource to exploit. It is almost seen as a new colonial frontier that can be extensively explored without regard for the consequences of our actions. In the past, we Europeans colonised the Americas, thinking it was a vast land devoid of peoples that could be plundered at will, only partially recognising our dark history later. A similar pattern is unfolding in space. Therefore, we should be mindful of our colonial history and recognise that space colonisation has serious implications for Earth’s environment and our future.
To give an example, I’d like to draw your attention to the work of my colleague at the National University of Singapore, Matthias Wong. He draws awareness on spacecraft light pollution, which is altering the appearance of the night sky. Light pollution by satellite reflectivity is becoming an issue, and ultimately affecting the Earth’s environment, affecting the night sky and the traditional practices of many communities worldwide that rely on the dark skies for navigation, social, and cultural knowledge, such as identifying star constellations. Protecting dark skies is essential for oceanic wayfaring traditions and many other communities around the globe.
The darkness of space must be preserved from excess brightness and light pollution. This also involves limiting the number of space objects launched into the night sky. It’s crucial to safeguard the sky as a form of cultural heritage. While satellites are necessary for weather forecasting, climate change monitoring, measuring ice cap melting, and telecommunications, we must also protect our relationship with the night sky.