Space 'road rules' needed to reduce junk

Space is becoming an increasingly perilous place. It is dangerous, of course, because more and more countries are venturing into orbit.

But it is also dangerous because there are precious few international agreements governing national actions in space. No rules of the road forced Russia to de-orbit its long-defunct Cosmos 2251 spacecraft, which would have prevented its collision with Iridium's communications satellite recently. Yet this event probably left at least 2,000 pieces of hazardous debris in orbit around the earth; all of this debris will have to be tracked and avoided by other spacecraft for decades.

Instead of continuing to cling to the theory of "freedom of action" in space, all space-faring countries would be well advised to sit down and talk about mutual restraint and coordination. The alternative is unacceptable: We will lose our ability to operate in some of the most useful regions of orbital space, particularly those closest to the earth (60 to 1,000 miles up).

In many respects, our level of sophistication in dealing with space "traffic management" - the active and dead satellites and orbital debris that whiz around the earth at speeds of 18,000 miles per hour - is reminiscent of the early days of car travel, when a lack of rules resulted in frequent accidents.

The difference in space, of course, is that the fragments from past collisions remain in orbit, at least until they are eventually dragged down by gravity and burn up in the atmosphere. The February 2008 shoot down of a military satellite by the United States created a large amount of debris, but, at an altitude of 150 miles, it fell out of orbit in two months. At 500 miles up, by contrast, debris will orbit for decades. Much above that, it will persist for centuries.

Recently, an effort led in part by the United States succeeded in gaining UN passage of a set of voluntary international debris-control guidelines. These useful but very general protocols urge countries to limit their debris, to refrain from blowing things up in space and to place dead spacecraft in "parking" orbits or, if at lower altitudes, in relatively rapid de-orbiting modes.

The problem is that not enough countries are observing these guidelines because they're just that - guidelines. They don't have the force of international law, they offer too many loopholes and violators face no sanctions. The Iridium-Cosmos collision is the clearest sign yet that we need to devise cooperative solutions to our common problems in space - before it is too late.

US Strategic Command tracks more than 18,000 orbiting space objects, but it lacks the manpower to provide warnings of possible collisions to all except manned spacecraft and the most crucial United States military satellites.

Setting up an international warning network, paid for by the users of space, should therefore be treated as a priority. Such an entity could be run by a consortium of national militaries or space agencies, possibly under UN auspices. (The United Nations already oversees a space registration convention, which requires countries to list launches, orbits and the purpose of missions. But it stops tracking spacecraft once they've been launched.)

While there are security concerns associated with such a proposal - we don't want the world to know the location and number of our military satellites - it's important to remember that many sensitive satellites are large and easily found, even by amateur astronomers. It's also worth remembering that in the thick of the Cold War we signed an Incidents at Sea Treaty with the Soviet Union, which put in place measures to reduce the chance of accidents between American and Soviet ships and planes.

Other steps should be taken too. We should ban the intentional destruction of satellites in orbits above 150 miles (and possibly below as well). We should also create a legally binding code of conduct for space (laying out specific sanctions for violators) and embark on new efforts to bring about international coordination of radar systems. All these ventures could reasonably be undertaken by meetings of space-faring states or at the Conference on Disarmament in Geneva.

Until now, the debate about space has focused largely on the question of who is up there. Now two new questions have arisen: What is up there, and where is it?

The author is an associate professor at the Naval Postgraduate School The New York Times Syndicate.

(China Daily 02/24/2009 page9)