Military to shoot down spy satellite

After the shuttle lands Wednesday, the military will shoot down its own spy satellite.

The military plans to shoot down a bus-sized U.S. spy satellite, preventing it from re-entering the atmosphere randomly. The missile launch will be scheduled after the Atlantis' Feb. 20 landing but likely within two weeks.

The 5,000-pound spy satellite carries 1,000 pounds of toxic hydrazine and will be shot down when it is orbiting about 130 nautical miles up.

Some 50 percent of the debris will fall and burn up within hours; the rest will fall and burn up within weeks. Otherwise, the hydrazine tank could land intact, full of slushy fuel.

"It is the hydrazine that makes this different," said Gen. James Cartwright, vice chairman of the Joint Chiefs.

The hydrazine tank would spread toxic fumes over an area the size of several football fields.

"That's not an outcome we want to see," NASA administrator Mike Griffin said.

A modified ballistic missile will be launched from an Aegis cruiser. The missile will be launched after the shuttle lands on Wednesday. Two backup missiles will be available.

A criticized Chinese test scattered debris in orbit, while this test brings the debris down from orbit, said Griffin.