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.
