Glenn Reynolds Explains Satellite Collisions under International Space Law

The collision of two satellites in orbit around the earth, creating a cloud of debris and some amount of risk to the international space station, turns our thoughts to the international law of space.  And thence to Glenn Harlan Reynolds, who explains it for us in a column at Popular Mechanics.  I, for one, was surprised to actually read the 1972 convention and see that it provides a fault based system for collisions between two spacecraft in space, whereas it provides for “absolute” liability in the case of damage to things on the ground or aircraft.  

The collision of a dead Russian satellite with an Iridium communications satellite left a cloud of debris and a number of questions. But, contrary to some people’s impressions, it didn’t occur outside the law. Outer space is not a lawless region; it is governed by international law (and, in the case of U.S. spacecraft, or the U.S. parts of the International Space Station, by American law). 

In fact, damage to and by spacecraft is covered by the 1972 Convention on International Liability for Damage Caused by Space Objects. Under that treaty, liability for damage caused to people or property on the ground is “absolute”—meaning that the country that launched the spacecraft is liable for damages even if there was no negligence. The same is true if a crashing space object strikes an aircraft. It does not matter how the accident happened: If your spacecraft does damage, you pay. This rule was made to protect people on the ground: Expecting everyone to be on guard against crashing satellites is asking a bit much. 

In space, however, things aren’t so straightforward. When one spacecraft collides with another, there’s only liability if the spacecraft operator is at fault—that is, negligent in some way. But what’s negligence in the context of Wednesday’s crash? That’s not so clear. Operating a spacecraft in a way that poses a foreseeable risk to others is probably negligent, but in this case the Russian Kosmos military satellite was described as “defunct,” meaning that it had either broken down, or run out of maneuvering fuel. There are lots of such satellites in orbit, and although good practice calls for their operators to either de-orbit them, or to boost them into harmless parking orbits, this is not always possible, and it would be hard to argue that failure to do so constitutes negligence. While we may develop standards of practice (“rules of the road” for space) someday, such standards would require space operators to ensure that satellites don’t remain in high-traffic orbits at the end of their lives. Failing to do so would give rise to damages. Space law is not yet this forward-looking.