Reuters

ON THE roads, at sea and in the air, mankind has invented sensible rules to avoid accidents. In space, something like a free-for-all prevails. On a good day, spacefaring nations observe certain understandings, such as how to launch objects safely into orbit. On a bad day, it is celestial road rage.

A year ago, the Americans fumed when China tested a missile by shooting up one of its own weather satellites. One thing that made the test look anti-social was that it created the worst-ever cloud of man-made debris in the heavens. Ever since, other satellites have had to be moved periodically to avoid the shrapnel. And bumping into things is not just a matter of collecting scratches. At orbital speeds, colliding with an object the size of a pebble can ruin the day of a multi-billion dollar spacecraft.

There was, however, a second reason for America's anger over the Chinese test. America is space's pre-eminent military power. Or, more exactly, given that America has held back from putting weapons in space, it has used space to preserve and extend the pre-eminent military power it enjoys on earth. By using a missile to blow apart one of their own satellites, the Chinese showed that they could if they chose blow apart the spy and navigation satellites on which America's armed forces (and grateful drivers everywhere using GPS systems) depend. Indeed, the Chinese test may have been intended to send precisely this warning.

Given the dangers of a clash in space, and the degree to which the military and civilian uses of space have blurred together (see article), why have the big powers so far failed to negotiate either arms-control agreements or simple rules of the road, as they have on earth? In the case of arms control, the explanation is that America is suspicious. Russia and China have offered to negotiate a treaty banning space weapons. The Americans are not sure whether that is feasible.

How, for example, do you define what is a weapon, since any flying object can be made into one simply by bashing it into someone else's satellite? Besides, the Americans fear that as top space power, with ambitious plans for anti-missile systems still in the pipeline, they would end up losing from any new treaty, while Russia and China would have to give up less. On January 23rd a conference on disarmament is due to reopen in Geneva, but on this point it is stuck. America says it is ready to talk in general about space security, but only if others agree to negotiate a treaty to stop production of fissile material for nuclear weapons. Thanks to the opposition of China and Pakistan, that may not happen any time soon.

America's reluctance to sign any arms-control agreement that might jeopardise its national security is understandable. But its refusal even to begin to talk about a weapons ban in space has been unduly rigid. Once negotiations started, some of its doubts about the possibility of a useful and verifiable treaty might be dispelled. Besides, it is not at all clear that America itself would lose from the existence of such an agreement. Since the Americans have invested most in space, it is they who could suffer more if war or accident were to fill space with clouds of debris and kill or blind their satellites.

At least write a spaceway code

In the meantime, the big spacefaring countries ought to consider negotiating some less formal rules of the road. These would seek to stop dangerous driving, maintain safe distances and, most importantly, avoid harm to each other's satellites. If they co-operated on surveillance of space, such countries could also do a much better job of monitoring space debris. America would still have the fanciest spacecraft, and could reserve its judgment on arms control. But in heaven as it is on earth, the more eyes on the road, the safer for all.