January20, 2007:
On January 11th, China launched an anti-satellite system (a KillSat,
or Killer Satellite). The target was an old Chinese weather satellite, about
850 kilometers up. 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 about 800 are truly
dangerous (at least four inches long, wide or in diameter). What China did was,
in terms of technology, something the U.S. and Russia had demonstrated over
three decades ago. No big deal, unless you actually use it. While China has now
demonstrated its ability to destroy satellites (at the cost of a launcher and a
maneuverable KillSat), it has also caused a major stink among the dozens of
nations that own, or use (usually via leasing arrangements) the several hundred
satellites in orbit. That's because this Chinese test increased the amount of
dangerous space debris by about eight percent. That's a lot. By common
agreement, nations that put up satellites, include the capability for the bird,
once it has reached the end of its useful life, will slowly move closer to
earth, until it burns up as it enters the thicker atmosphere. This approach
leaves no debris, which can collide with other satellites, behind. Even a small
piece of satellite debris can, when hitting another satellite at high speed,
destroy, or fatally damage, it.
Twenty
years ago, Russia and the United States agreed to halt such tests, in order to
reduce the amount of "space pollution" that threatened all current, and future
space satellites. Moreover, there was the practical problem of cost. Having
launchers standing by, to put a sufficient number of KillSats up, would be
enormously expensive. And it would simply encourage others to do the same
thing, which would cancel the original anti-satellite effort. China has
ignored, so far, any criticism of its KillSat test, and dismissed the risk of
starting an orbital arms race. But China has angered the other users of orbital
space, and earned the contempt of those nations as well.