the three astronaut residents of the International Space Station scurried for safety in a Soyuz module, preparing for a possible impact with a piece of space junk—a 1/3-in.-wide part of a motor of a satellite-carrying rocket. If struck, the station could experience a drop in air pressure that could kill all inhabitants. NASA usually moves the ISS out of the orbit of debris, but some junk with erratic orbits can defeat tracking and surprise mission control, as happened during this incident. The debris missed the ISS and the astronauts exited the Soyuz “life raft,” but the junk is believed to have come within the station’s safety zone of 2.8 miles. The event raises a thorny legal question: Who is responsible for damages caused by space junk?
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 would be negligent if debris were to hit the ISS? That's not so clear. Operating a spacecraft in a way that poses a foreseeable risk to others is probably negligent, but this was junk, no longer an operable craft. 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.
Worse yet, while intact satellites can be traced back to their countries of origin, debris fragments—which because of the tremendous velocities involved can be enough to wreck a spacecraft even when they're as small as a golf ball—will often be from unidentifiable sources. Some scholars have proposed an international regime that would "tax" countries for debris cleanup based on the amount of material left in orbit, but such proposals remain purely academic.
Finally, current space law doesn't allow another solution to the space-junk
problem: Salvage. Under the 1967 Outer Space Treaty,
nations retain "jurisdiction and control" over their spacecraft even when they are inoperable, meaning that a salvage operator wouldn't be able to take title or claim an award for recovering a defunct craft as is done on earth. Space lawyers (yes, there are space lawyers) have been arguing for years that the proliferation of space junk
makes some sort of salvage law necessary, but up to now there has been little progress. The technology for recovering defunct satellites is there, though cleaning up smaller debris fragments would be much, much harder. That's a reason to try to get a handle on the problem sooner, rather than later. A space salvage law might even give a shot in the arm to commercial space efforts, by providing yet another money-making option.
Glenn Reynolds, a contributing editor to Popular Mechanics, is co-author (with Robert P. Merges) of
Outer Space: Problems of Law and Policy. He teaches space law at the University of Tennessee.