Navy to shoot down spy satellite Wednesday

The US Navy will to try to shoot down a faulty spy satellite with a modified anti-missile missile on Wednesday.

Without any intervention, officials believe the 5,000-pound secret spy satellite would fall to Earth on its own in early March. Because it malfunctioned immediately after it was launched in December 2006, it has a full tank -- about 1,000 pounds -- of frozen, toxic hydrazine propellant on board.

Authorities said the fuel tank probably would survive re-entry and could disperse harmful or even potentially deadly fumes over an area the size of two football fields. Hydrazine is similar to chlorine or ammonia in that it affects the lungs and breathing tissue.

Pentagon sources said the Navy is attempting to take its first shot about 10:30 p.m. ET, or 5:30 p.m. Hawaii time. A formal notice was issued earlier this week, warning ships and planes to stay clear of a large area of the Pacific Ocean west of Hawaii. The window covered by the "Notice to Airmen" begins about 9:30 p.m. ET Wednesday (4:30 p.m. Hawaii time) and lasts for 2½ hours.

Among the team's challenges was modifying the sensors designed to detect the heat from an incoming warhead because the satellite will be much cooler.

Selected for the mission is the Aegis-equipped cruiser USS Lake Erie, which is fully equipped with sea-based missile defense systems, and has long been the Navy's primary ship for the sea-based missile defense program, officials said.

The Lake Erie will be joined in the Pacific by two destroyers, the USS Decatur and the USS Russell. The Lake Erie will fire the missile, the Decatur will feed trajectory information to the Erie, and the Russell will be the Decatur's backup, authorities have said.

The satellite and the missile will be heading toward each other at about 22,000 mph. The satellite is about the size of a school bus, authorities have said, and the missile will be aimed at its fuel tank, which is about 3 or 4 feet long.

The missile would release a "kinetic kill vehicle," enabling it to "see" the satellite and adjust its course toward it, officials have said. After the first of the three missiles is shot, officials will determine if the satellite was hit.