The sky is falling but it’s under control

THE ISSUE The military plans to shoot down a failed orbiting spy satellite to avoid its uncontrolled tumble into the atmosphere.

Any announcement that even hints that the sky is falling is bound to cause nervousness, and describing the landing area as 70 percent water is hardly reassuring to those of us living in the middle of it. However, the Pentagon promises to "explore options to mitigate the danger to humans" in an operation that is necessary to prevent larger potential harm.

Late this month or in early March, a Pearl Harbor-based cruiser will fire rounds of missiles at a failed orbiting spy satellite the size of a school bus. President Bush ordered the shooting to avoid the spread of a half-ton of hydrazine, a potentially deadly fuel in the satellite, before it can fall to Earth and spew the fuel.

When China tested an anti-satellite system by targeting an old weather satellite, the U.S. complained. The United States has refrained from such tests since President Reagan ordered the successful shooting of a satellite in 1985. The announced shooting is not a test.

Scientists figure that the spy satellite, launched in December 2006 but never operational, would tumble uncontrollably to Earth if allowed to re-enter the atmosphere intact and break apart on a random path. If the first shots miss, more will be fired until the satellite is struck and comes apart.

Satellites about to run out of fuel routinely are taken out of orbit into a controlled re-entry, with parts falling into the ocean. Debris from the Chinese weather satellite is expected to decay for decades, posing a danger to vehicles in orbit.

The U.S. spy satellite is 2.5 times the size of China's weather satellite. David C. Wright of the Union of Concerned Scientists predicts the missile strike could produce 100,000 pieces of debris, most of which is expected to fall into the atmosphere over a period of weeks.