While life on Earth has been dramatic enough lately, there’s also been an unusual amount of news from space in the early months of 2025. So far, debris from SpaceX and Blue Origin rockets has landed in locations including the Bahamas, Florida, Poland, and Turks and Caicos and caused flight delays at airports in Florida. On February 18, NASA estimated that asteroid 2024 YR4 had a 3.1 percent chance of hitting Earth in 2032—the highest probability of impact ever recorded by the agency—although they later reduced that estimate to 0.004 percent.
For decades, asteroids, rockets, satellites, and associated space junk have all posed risks to our planet’s infrastructure and people. In response, space law has grown into what we know today, starting in the mid-20th century by the United Nations. Shaped by the international resolutions, treaties, and organizations that have been created to regulate these threats, the field has grown in relevance and importance as more countries and private entities pursue activities in space.
Only a few universities–including NYU–currently offer courses on the subject, but that is likely to change as the field grows. NYU News spoke with Benedict Kingsbury, Murry and Ida Becker Professor of Law, and Katrina M. Wyman, Wilf Family Professor of Property Law—co-teachers of the NYU School of Law course “Space and Planetary Law & Governance” and experts in international and environmental law—about the recent headlines, the still-developing discipline, and how it could shape Earth’s future.
So if space debris lands in your backyard, what do you do?
Wyman: There’s an international convention related to this, the Liability Convention of 1972. Basically, it says that the country that licensed the launch of the item that has fallen in your backyard would be strictly liable. However, this convention has only been formally invoked once–which was in 1978, when space debris landed in Canada, and Canada went and pursued the Soviet Union.
When some space debris landed in Saskatchewan (in May 2024), SpaceX sent some employees to the farm where the debris landed, and they picked it up and took it away without any intervention by the Canadian government or the U.S. government.
But property damage is not the only important and interesting issue. We’re not familiar with any examples where somebody’s been killed from space debris falling—but that could potentially happen. There was also a study done about what could potentially happen if the debris hit an airplane. That’s another concern.
Earlier this year, there was a lot of news about an asteroid potentially hitting Earth. If one is someday determined to be likely to impact our planet, how do we decide who should be involved in the response?
Kingsbury: I think, in terms of the academic terminology for this kind of question, it’s a “public goods problem.” That is, we all benefit from deflecting an asteroid which is going to hit Earth, but only a small number of players are going to bear the cost of running these programs. Of course, if they’re big countries with big economies and they have a lot at stake, they would feel, “Well, it’s worth it to do this.” There are also ancillary benefits because these countries get expertise, they’re tracking space objects, they can use that same information to avoid risks of damage to their own spacecraft and satellites or even for navigation and perhaps other exploratory things. So there may be enough side benefits from planetary defense that it makes totally compelling sense for one country to do it, but there is also a public goods problem.
It’s not a problem like climate change, where you need a lot of people and places to reduce emissions for mitigation, and you need a big strategy involving millions or even billions of actors. If an asteroid is coming, it’s enough to have just one actor who actually deflects it, among perhaps a dozen actors capable of doing it. At the moment there’s no conflict about the goal – everyone agrees on that. However, there is a question about who is willing to invest a big amount in being prepared to do it. Planetary defense involves trying to deal with something like an asteroid that when near Earth would be coming at enormous speed and could cause tremendous damage—yet that kind of event is very rare and very unlikely. Most of the effort is just to track what’s happening, to construct good far-distance interception equipment, and to be prepared.
A pressing issue becoming more and more common has to do with orbital debris. When the debris is in orbit, it’s potentially very dangerous to other satellites and rockets because it’s in areas where there is now much more satellite activity, especially in Low Earth Orbit.
Why is it dangerous? How does space law work here?
Kingsbury: Low Earth Orbit, which is considered the zone up to 2,000 kilometers (or about 1,200 miles) above Earth, is roughly the most active area. That’s where Starlink and the International Space Station are. It's also an area that other rockets have to pass through if they're going further out. That area is becoming much more crowded with active satellites, but there’s also an enormous amount of what’s called “space junk” in orbit. Some of it is from defunct satellites and broken-off pieces from rocket bodies or fragmented satellites. Because the space junk is all orbiting at very high speed, it can cause tremendous damage that could destroy a satellite—and if it happened to be something with a crew in it, a collision could lead to death. So there’s a serious risk there, and it’s a much more likely risk than an asteroid hitting Earth. There’s a huge collective interest in cleaning it up, but that is also a big public goods problem.
Additionally, in theory, the state or entity that launched a craft still has a responsibility in an accident, but in practice, often it’s not known who’s responsible for some little piece of junk anymore. Quite often no one is really at fault. The things that are in orbit, many of them, they’re not maneuverable. Some of them are just little pieces, and while some people hope in the future to ablate them with lasers or catch them with magnets, there’s nothing very easy to be done. So there’s a lot of risk of damage and accidents without anyone being liable for it and without much ability to really prevent them.
There’s also a really important function of space tracking, which goes under the name of “space situational awareness.” So far, the U.S. Department of Defense has been the main provider of information to people operating satellites or any active spacecraft that may be at risk of a collision with something like a piece of space junk or another satellite. Those are called conjunction events, and notices get sent out to operators, but it’s often just an estimate. At the moment, there’s some international coordination, but there are no binding international agreements on space tracking or on collision avoidance. There are just a lot of understandings of who’s going to get out of the way. For now, the only binding law is about negligence liability if you cause an accident, but that’s very difficult to enforce and not enough to rely on.
You’ve mentioned the space efforts of different countries and companies and organizations. How are these efforts coordinated?
Kingsbury: Well, the United Nations does not itself operate satellites. The very expensive satellites, as well as the big telescopes on earth and the telescopes in space–like the Hubble and James Webb telescopes–are operated either by individual countries or groups of countries. These days, more and more satellites are privately operated, and there is impressive private launch capability as well.
There’s a lot of collaboration between two or three countries—or bigger groups of countries—that continues the long pattern of the U.S. and Soviet collaboration in the 1970s. The International Space Station is a big symbol of that. There’s a lot of information sharing and scientific collaboration through the telescope programs, satellite programs, and human spacecraft programs. It’s done mainly by bilateral agreements, but often with the aim of sharing the data to the whole public.
How do you define space law, and what do you cover in the course?
Wyman: I would say space law is an effort to set some rules or principles to govern and coordinate human activity in outer space, and it’s a mixture of all different kinds of law and policy. It’s international law, domestic law—a lot of it is rules of the road or norms-based because there’s actually not that much traditional law in space law.
I teach environmental law, and I think of space as another environment. I’m interested in the lessons we can learn for space from our successes and failures in managing the Earthly environment. I’ve been thinking recently about how people might be able to develop a politics to facilitate protection of outer space.
Kingsbury: I agree. Space law is about facilitating, organizing, and channeling human activities as they become more intensive off the Earth. It’s trying to avoid conflict, trying to be efficient, and also to enable fairness and long-term thinking about what could otherwise be short-term decisions.
Space law has become a vocation for law students to go forth and do, but also there are a lot of people with a real passion for space, so in our course we also discuss a lot of science fiction. We’ve discussed Dune, The Expanse, The Three-Body Problem, and it’s striking how many people have their imagination of what’s likely to be happening in space already structured by science fiction. And often those writers have identified issues which now are getting much closer to being things that are really happening—as well as the challenges of managing the core issues of morality, conflicts of fairness, and values.
I think our contribution is to try to bring together international law with environmental law, property law, and commercial contract law to make some package that is both hopeful and forward-looking, but also practical and workable.
Posted March 28, 2025