In 2015, the United Nations adopted the 2030 Agenda for Sustainable Development—the Sustainable Development Goals (SDGs)—a universal call to action to protect the planet for future generations and ensure that all people will enjoy peace and prosperity. These 17 goals included the elimination of poverty, hunger, and inequalities, the promotion of education, and the promotion of sustainable development worldwide. With the rapid development in Low Earth Orbit (LEO), there are growing concerns that an 18th SDG should be adopted for space.

This goal calls for the sustainable use of Earth’s orbit by space agencies and commercial industry and the prevention of the accumulation of space junk. This has become a growing problem in recent years thanks to the deployment of satellite mega-constellations and the “commercialization of LEO.” In a recent study led by the University of Plymouth, a team of experts outlined how the lessons learned from marine debris mitigation could be applied to space so that future generations can live in a world where space truly is “for all humanity.”

The study was conducted by an international collaboration of experts from the International Marine Litter Research Unit (IMLRU) at the University of Plymouth, the Aukland Space Institute and the Centre for Putaiao at the University of Auckland, the School of Earth and Climate Sciences (SECS) at the University of Maine, PBLWorks Ltd., the Arribada Club, Science StoryLab Ltd., the Centre for Aeronautics at Cranfield University, the Zoological Society of London (ZSL), NASA’s Jet Propulsion Laboratory, and many other universities, institutes, and commercial space companies.

According to the ESA’s Space Debris Office (SDO), there have been 6,740 rocket launches since the beginning of the Space Age in 1957. The number of satellites these rockets deployed close to 20,000 satellites in orbit, about 13,230 are still in space while about 10,200 are still operational. These satellites have immensely benefited society, providing global communications, high-bandwidth internet, and other services used by billions of people worldwide. They’ve also enabled Earth observation science, allowing scientists to monitor ecological systems, forest fires, natural disasters, and climate change.

However, these launches have also left LEO littered with spent rocket stages, inoperable satellites, and debris from explosions or collisions. According to the SDO, there are currently 40,500 space debris objects greater than 10 cm (~4 inches) in LEO, and over 100 million measuring from 1 mm to 10 cm (~0.04 to 4 inches). This could lead to a scenario known as Kessler Syndrome, where the accumulation of debris increases the likelihood of more collisions, creating a vicious cycle that poses a significant hazard to active satellites and operations in space.

“It’s important because space is a finite resource in dire need of environmental protection, and it’s been neglected thus far because it hasn’t been universally accepted as such. Our collective actions are leading us to a tragedy of the commons,” said co-author Moriba Jah, a Professor of Aerospace Engineering & Engineering Mechanics at the University of Texas at Austin.

In 2009, Kessler wrote that attempts to model the orbital debris problem indicated the debris environment had already become unstable. With the number of launches dramatically increasing annually, it is clear to many that the time for action is now. Dr. Imogen Ellen Napper, a Visiting Research Fellow with the IMRLU, led the study that recently appeared in One Earth. As she said in a University of Plymouth press release:

“The need to protect and connect our natural environments, from the ocean to Earth’s orbit, has never been more urgent. Both are vital to the health of our planet, yet increasingly under threat from the pressures we place on them. There is growing recognition that marine litter knows no international boundaries, and the same applies to space debris. A UN-backed agreement would be a crucial step in safeguarding Earth’s orbit for the future.”

Their work builds on a previous article titled “Protect Earth’s orbit: Avoid high seas mistakes,” authored by Dr. Napper and many of her colleagues who contributed to this latest paper. In the article, the team cited how insubstantial maritime governance has led to overfishing, habitat destruction, deep-sea mining, and plastic pollution. They further called for a legally binding treaty to ensure that the future expansion of the global industry does not irreparably harm Earth’s orbit. Said co-author Dr. Thomas Dowling, a lecturer in Remote Sensing & Geospatial Science at the University of Auckland:

“Not so long ago, our oceans were regarded as infinite resources to plunder and infinite sinks for our waste. We now know that view was grossly mistaken – many marine environments are now barren wastelands and more than eight million tonnes of plastic debris is estimated to enter the ocean every year. Earth’s orbit is a similar finite environment to the ocean, and mindlessly exploiting the orbital environment is repeating the mistakes of the past.

“It’s time to create policies to regulate what we’re putting in space, and we need to ensure objects entering orbit are safe, sustainable, and serving essential – or at least important – purposes for significant numbers of people around the world.”

“Just like plastic pollution and climate change, space junk is an issue that transcends borders,” added co-author Professor Heather Koldewey, the ZSL’s Head of Ocean and FAIRER Conservation. “Our ongoing efforts to protect the ocean highlight how important UN-backed agreements are for managing this crisis. It’s key we learn from the challenges and solutions in tackling marine debris and act now to protect our planet’s orbit.”

In their article and study paper, the team argues that SDG18 should draw direct inspiration from an existing goal—SDG14: Life Below Water, which calls for a commitment to “conserve and sustainably use the oceans, seas and marine resources for sustainable development.” While several organizations have begun to recognize the need for action, the authors say an additional SDG could be the means through which a global call to action could be made. The necessary mechanisms could be developed and enforced.

They also argue that SDG18 would complement the existing SDGs that emphasize how space technology will support an improved understanding of global issues. This includes Earth Observation (EO) satellites for tracking climate change, organizing disaster relief, and providing geolocation through the Global Navigation Satellite Systems (GNSS). However, the UN acknowledges that space-based research contributes to economic growth, increased food production, medical advances, access to research facilities, and connecting remote and isolated communities to services.

If this study emphasizes one thing above all, it is the interconnected nature of humanity’s efforts in space and life here on Earth. At the same time, it highlights the need for proactive measures and legal frameworks to address issues of global importance before they become unmanageable. Lastly, it reminds us that if humanity is to achieve the “Great Migration” and become an interplanetary species, we need to avoid making the same mistakes in space that we have on Earth.

The study was conducted with funding provided by the National Geographical Society.

Further Reading: University of Plymouth, One Earth