US spy satellite USA 193 was launched on December 14, 2006 but malfunctioned shortly after being placed in orbit. In January the satellite was reported to have lost orbit and falling back to Earth. This prompted the US government to form a plan to destroy the satellite with a missile due to the 1000lbs of toxic hydrazine fuel stored onboard.
The USS Lake Erie will fire a Standard Missile-3 (SM-3) missile at the satellite 130 miles above the Earth. The impacts of the two objects colliding will hopefully destroy the target. link: 1, 2
UPDATE: US Department of Defense confirms that on February 20, 2008 at approximately 10:26PM EST the SM-3 missile was launched and hit the satellite USA 193. link