By Jim Miklaszewski, NBC News Chief Pentagon Correspondent
Pentagon officials tell NBC News that a U.S. Navy ship is preparing to launch a missile over the Pacific on Wednesday night, in an attempt to shoot down a dead spy satellite orbiting out of control in space. If all goes as planned, the USS Lake Erie, an Aegis cruiser, will launch the SM-3 tactical missile at about sundown Hawaii time (or about 10:30pm EST) from a position about 600 miles northwest of Hawaii.
The spy satellite lost all power almost immediately after it was launched into space in December 2006. Without power, the 5,000-pound satellite, about the size of a school bus, would be expected to make an uncontrolled re-entry into the atmosphere and crash in early March. Although half the satellite would be expected to burn up on re-entry, U.S. officials fear that the 1,000 pounds of potentially deadly hydrazine fuel on board pose a risk to people on the ground. Military and NASA officials say that, because of that threat, they decided to attempt to destroy the satellite in space.
The three-stage SM-3 missile carries a "kinetic-kill" warhead that employs infrared sensors to guide it to the target. With no explosives, the warhead must slam into the target at a closing speed of 22,000 miles per hour to destroy the satellite, which is 130 miles above the earth. Since the satellite has had no power, the intercept must occur at a precise time when the sun's rays actually heat the satellite so the warhead's infrared sensors can detect and target the satellite. Classified computer software will also aim the warhead directly at a specific point on the satellite to hit the hydrazine fuel tank itself. The entire operation, from the launch to the "kill," should take approximately 80 seconds, the officials said..
Since the satellite would be destroyed in a low orbit, about 130 miles above the earth, US officials said most of the debris would fall harmlessly through the atmosphere and not orbit the earth as "space junk."
The satellite, designated U.S. 193, belongs to the highly-secretive National Reconnaissance office and is loaded with sensitive, top-secret imaging devices. U.S. officials deny, however, that the decision to destroy the satellite in space was an effort to keep the classified material from falling into the hands of the Russians, Chinese or other U.S. adversaries.
