On 10 February 2009 two satellites collided in orbit ­– a good time to think about some of the rules governing objects in outer space

Why Space Debris Mitigation is needed

Satellites don’t collide often, but when they do, the result is striking: they impact at enormous velocity (‘hypervelocity collision’) and can be pulverised into hundreds or even thousands of pieces of debris. Mind you, that debris doesn’t immediately fall to Earth. It continues to orbit around it: hundreds of uncontrollable satellite left-overs, ready for their next encounter. So who is liable when two satellites collide? Astonishingly, not necessarily the owners. It’s also not the operators who controlled the satellites (or stopped doing so). It’s what space law calls the “launching State”, i.e. the state which launched the satellite or procured its launch service, or from whose territory or facility the satellite was launched.

This international rule adopted in the early days of spaceflight (the 1950s and 1960s) seemingly allows for easy identification of a ‘culprit’: a spectacular rocket launch is difficult to hide, after all. But 21st Century spaceflight has become a little less simple: international joint ventures, private operators, cross-border cooperation, aerospace vehicles – that’s much food for thought for the lawyers and the regulators. Compare the dusty dirt roads and horse-drawn cabs of yesteryear with the traffic volume on a modern highway nowadays. Perhaps it is becoming time to discuss space traffic management too, just as we gradually introduced detailed rules for regulating terrestrial road traffic, from bikes to trucks, from pedestrian zones to freeways.

Space law is a really fascinating field covering the legal framework for activities conducted in outer space. But it does need to try and keep up with all the major developments we are witnessing in space and be on hand to step in when things do not go entirely according to plan.