By Marc Kaufman and Josh White
Washington Post Staff Writers
Thursday, February 21, 2008
A missile fired from a Navy cruiser in the Pacific Ocean hit an out-of-control spy satellite falling toward Earth last night, Pentagon officials said.
They said that a single SM-3 missile fired from the USS Lake Erie hit the satellite at 10:26 p.m. Eastern time. The missile struck the dead satellite about 150 miles above Earth as it traveled in orbit at more than 17,000 mph.
Military officials had hoped to rupture the satellite's fuel tank to prevent 1,000 pounds of hydrazine from crashing to Earth, a situation they depicted as potentially hazardous for people on the ground. It was unclear last night whether the missile hit was able to break up the fuel tank, but Pentagon officials said they hope to determine that within 24 hours.
A defense official said last night that the military believes it got a "pretty solid" direct hit on the satellite.
Before last night's intercept, some experts had expressed doubts about the seriousness of the risk and questioned whether the shot was an excuse to perform an anti-satellite test that many people around the world found controversial. Skeptics in the arms-control community have speculated that the administration chose to undertake the shoot-down partly to test missile defense technology.
Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics and satellite tracker, said after the shoot-down that he had not heard any reports of debris spotting but that "I know people are on the lookout." He said that around midnight the debris was probably over Australia, but that it would be over Canada 30 minutes later.
"Due to the relatively low altitude of the satellite at the time of the engagement, debris will begin to re-enter the Earth's atmosphere immediately," the Pentagon said in a statement. "Nearly all of the debris will burn up on reentry within 24-48 hours and the remaining debris should re-enter within 40 days."
Pentagon officials said earlier that while the military has been able to precisely track the satellite in orbit, shooting it down was a daunting challenge, with the actual window of opportunity for a successful shot open for only about 30 seconds.
President Bush made the initial decision to shoot down the satellite at the urging of his national security team, which said that the rocket fuel posed a very small but real risk to people on Earth. Defense Secretary Robert M. Gates, who is traveling abroad, made the final decision about when to shoot.
In steps taken in coordination with the Defense Department, the Centers for Disease Control and Prevention sent out a health advisory yesterday that warns that those who breathe the rocket fuel can suffer convulsions, tremors or seizures. The administration also mobilized what it called six "joint interagency task forces" nationwide to reach the site of any satellite debris.
"There's only a small chance the hydrazine will land in a populated area or cause injury or death, but there's still a chance that it could," said Bryan Whitman, a Pentagon spokesman. "The United States has a chance to mitigate that risk or possibly eliminate it. We have this capability and can reduce the risk to human life on this planet, and that's why we're doing it."
Scientists, arms-control advocates and others said the shoot-down was based on questionable modeling by the government of the risks to human health and was a danger to the future peaceful use of space.
Some scientists calculated that the tank of hydrazine could not possibly survive a descent through the atmosphere, and others said that even if it did, the chances of anyone being injured were extremely small. Some worried that the U.S. decision to adapt a rocket designed for missile defense to serve as an anti-satellite weapon would encourage other nations to experiment with their own anti-satellite technology.
In January 2007, China shot down an aged satellite orbiting about 600 miles above Earth and was roundly criticized by the United States and many other nations for doing so. That anti-satellite test created thousands of pieces of debris that will remain a potential hazard to orbiting spacecraft for decades.
Administration critics worried that debris from the U.S. intercept could harm other satellites as well, especially if the pieces are pushed far out into space by the force of the strike. But NASA Administrator Michael D. Griffin and Marine Gen. James E. Cartwright, vice chairman of the Joint Chiefs of Staff, said they expect half of the debris to fall to Earth quickly and the rest to remain in safe low orbit until it descends in the next few weeks.
Most information about the malfunctioning spy satellite is classified, but space and defense experts believe that it was launched from Vandenberg Air Force Base in California in December 2006 and that it malfunctioned soon after reaching low-Earth orbit. That spacecraft, called L-21 and commissioned by the government's National Reconnaissance Office, cost hundreds of millions of dollars and included the most advanced radar imaging technology, said defense analyst John Pike of GlobalSecurity.org.
He said there is "good reason" to believe that it was part of the National Reconnaissance Office's Future Imagery Architecture program, which was supposed to replace the larger spy satellites now being used. "The whole program has had problems" with challenging technology and contracts that were bid unrealistically low, he said. "And now this."
The National Reconnaissance Office is an arm of the Defense Department tasked with designing, building and operating spy satellites for the nation. While hundreds of these spacecraft have been launched in the past decades, few remain useful for more than several years, and so, to keep important orbits clear, they routinely are directed back to Earth. Generally, that is done with a controlled burn of a craft's remaining fuel, one that allows ground control to crash it safely into an ocean, analysts say.
In the past, the most important spy satellites were large, about 8 to 10 tons. The newer generation was supposed to be considerably smaller and lighter, making them potentially cheaper and quicker to launch.
Pike and others believe that the failed satellite was part of a controversial contract given in 1999 to Boeing, which had never built a spy satellite before, and ultimately the contract was taken from the company because of technological and financial problems.
Amateur astronomers who track satellites identified the December 2006 launch as troubled from the start. They reported that the satellite never left its low orbit for the higher one it needed and that the orbit gradually became lower.