January 16, 2008: U.S. Air Force space experts are still trying to figure out what China was trying to do, or prove, with their satellite killer test a year ago. China had launched an anti-satellite system (a KillSat, or Killer Satellite) that destroyed an old Chinese weather satellite, about 850 kilometers up on January 11th, 2007. That's at the upper range of where most reconnaissance satellites hang out. The KillSat hit the weather bird, and the result was several million fragments. Most of the pieces are tiny, but at least 817 are truly dangerous (at least four inches long, wide or in diameter). There are many such debris swarms up there, that have to be watched and avoided. But these other debris swarms are the result of accidents. For example, on February 19th, 2007 a new swarm was created because of the accidental explosion of a Russian rocket, that put over 1,100 dangerous fragments in orbit. Those two incidents increased the dangerous debris in orbit by about fifteen percent.

Subsequent information coming out of China indicates that the killsat test was more an indication of lack of discipline in the military, than a new national policy. Some of the generals were acting on their own. The reality is that a large scale use of killsats would be very difficult to carry out. For one thing, the Chinese would have to ready several dozen launcher rockets for near simultaneous use. That would be difficult to hide. There's also the difficultly of hitting many U.S. military satellites, because these birds are mobile and have the ability to change their orbits. That greatly complicates the job of a killsat, and in many cases renders killsats useless (as they end up stuck in orbits aiming for a target that has moved away.) Moreover, mobile, low orbit, satellites are not easy to track. When they are not in the sunlight, they are impossible to spot, and they are in the dark, so to speak, for part of every orbit.

But the worst aspect of a mass killsat attack is that the successful hits would pollute the most useful orbital space with debris. This space junk would make those useless for anyone, including China. That would make China an international pariah. It also makes whoever ordered last years killsat test a man of questionable judgment. That has apparently been realized already, but the Chinese are keeping the details secret. For now.