WASHINGTON _ The U.S. military has a “high degree of confidence” that a missile fired at a crippled spy satellite struck the satellite's fuel tank that was carrying 1,000 pounds of toxic hydrazine rocket fuel, Pentagon officials said Thursday.
A video released by the military shows a fireball and vapor cloud erupt as the missile strikes the satellite. The military believes the vapor cloud is eveidence that the missile destroyed the tank, releasing the hydrazine, an ammonia-like chemical that can be harmful if inhaled or swallowed. U.S. officials ordered the missile strike on the satellite out of concern the tank would survive re-entry into the Earth's atmosphere and land in a populated area.
“We are not proceeding as if we are going to take another shot,” said Marine Gen. James Cartwright, the vice chairman of the Joint Chiefs of Staff.
It will still be several days before the military can confirm it struck the tank, Cartwright said, as it studies data and several videos _ including one on the missile.
Debris has already begun falling over both the Atlantic and Pacific Oceans, but nothing has reached the Earth’s surface, the military said. The remaining debris will re-enter the atmosphere in the next 40 days.
So far, the military has not seen any debris larger than a football, Cartwright said.
Shortly after the military announced late last night that it had struck the satellite, China said it was on alert for falling debris and demanded details from the U.S. about its mission.
China’s concerns were as much about politics as safety. Last year, U.S. officials expressed concern about falling debris after China shot down one of its own satellites.
Wednesday’s strike was the first time the United States had attempted to strike a satellite with a missile.
In a statement, the military said that at 10:26 p.m. Eastern time, the USS Lake Erie, an Aegis class missile cruiser, which was 600 miles west of Hawaii launched an SM-3 tactical missile toward the satellite. The missile struck the satellite at 153 nautical miles above the Earth's surface.
Cartwright said the military confirmed it hit the tank at 10:50 p.m.
The mission was considered a major, if unplanned, test of America 's anti-ballistic missile program.
U.S. officials announced last week that the Navy would try to down the satellite out of concern that the hydrazine would fall over a populated area. The Centers for Disease Control and Prevention issued an alert about the substance and the Federal Emergency Management Agency provided local officials with guidelines for dealing with debris from the satellite.
The decision to shoot down the satellite was controversial. Some experts have suggested that the attempt is really an effort to expand the capabilities of the anti-ballistic missile system to include satellites and to counter China 's destruction of an aged weather satellite last year.
Others interpreted the mission as the military’s effort to find new uses for its controversial missile defense plan.
But Cartwright insisted the mission was only “to preserve life,” adding that there is little the military can learn from Wednesday’s launch that could apply to missile defense.
“We had to modify [the missile] away from missile defense,” Cartwright said. “It doesn’t cross over.”
Still, military personnel were clearly overjoyed that the mission had succeeded, noting that a miss would have raised new questions about the missile defense program.
“There were a few cheers” on the ship, Cartwright said.
The missile and the roughly 5,000-pound satellite, which failed shortly after it was launched in December 2006, closed in on each other at roughly 22,000 mph, officials said.
The shoot-down was not a sure thing. The missiles had to be reprogrammed to strike a satellite. Planners also had to wait until the satellite had been warmed by the sun so that the missile's heat seeking sensor would have an easier time finding it.
The two other missiles that were designed to shoot down the satellite had Wednesday launch failed, will now be re-configured back for their original purpose _ missile defense.