By Marc Kaufman and Walter Pincus
Washington Post Staff Writers
Friday, February 15, 2008
A Navy cruiser in the Pacific Ocean will try an unprecedented shoot-down of an out-of-control, school-bus-size U.S. spy satellite loaded with a toxic fuel as it begins its plunge to Earth, national security officials said yesterday.
President Bush made the decision because it was impossible to predict where a tank containing the fuel might land in an uncontrolled descent, officials said.
The Pentagon said it decided to use a modified, ship-fired anti-ballistic missile to make the attempt sometime after Feb. 20 to avoid creating debris that could threaten the space shuttle on its return from the international space station.
Marine Gen. James E. Cartwright, the vice chairman of the Joint Chiefs of Staff, said the Navy missile will be fired as the satellite reenters the atmosphere and "has a reasonably high opportunity for success." The Pentagon and NASA have been working on the missile modifications for the past three weeks.
Deputy national security adviser James F. Jeffrey said the decision was based on the fact that the satellite is carrying a substantial amount of hydrazine, a hazardous rocket fuel.
When the pending crash was first announced last month, however, National Security Council spokesman Gordon Johndroe and other officials minimized the danger, saying that the potential for harm was "very small."
Unless it is shot down, the satellite, which has been out of ground communication since its launch more than a year ago, is expected "to make an uncontrolled reentry . . . on or about March 6," according to documents the Bush administration provided to the United Nations yesterday. "At present," said an official notification sent yesterday to countries around the world as well as to the United Nations and NATO, "we cannot predict the entry impact area."
Officials acknowledged yesterday that many satellites and spacecraft parts -- some of them much larger -- have fallen to Earth in the past without causing harm. But they said the presence of 1,000 pounds of hydrazine -- unexpended fuel contained in a 40-inch sphere that was likely to hit the ground intact -- led Bush to approve the shoot-down.
The announcement set off an immediate debate on defense blogs and among experts who questioned whether there is an ulterior motive. Some experts said the military is seizing an opportunity to test its controversial missile defense system against a satellite target.
But others noted that the Standard Missile-3 has successfully been tested against warhead targets, which are far smaller than the satellite.
"There has to be another reason behind this," said Michael Krepon, co-founder of the Henry L. Stimson Center, a liberal arms-control advocacy organization. "In the history of the space age, there has not been a single human being who has been harmed by man-made objects falling from space."
NASA Administrator Michael D. Griffin insisted that the interception attempt is not a ruse to try the defense system on a satellite or to one-up countries that have made similar attempts. The administration was harshly critical of China when it destroyed an aging satellite in orbit a year ago.
The difference, Griffin said, "is, one, we are notifying, which is required by treaties and law, okay?" The Chinese satellite was destroyed at a much higher altitude -- about 600 miles -- creating a field of orbiting space debris that is hazardous for other spacecraft.
The United States and Soviet Union conducted anti-satellite tests in the mid-1980s but stopped once it became clear that the debris from the destroyed spacecraft became a danger to other satellites and even spaceships. Griffin said the low altitude at which the satellite will be targeted -- about 150 miles -- will minimize orbiting debris.
"The lower we can catch this, the quicker the debris reenters," he said. More than half the pieces will burn up or land before making two revolutions around Earth, and the rest will come down in "weeks, maybe a month, but it's a very finite period of time that we can manage."
Jeffrey said that the fuel tank is the only piece of the craft that was not expected to break up on reentry and that it is hoped that the missile can destroy it in space. If it hits the ground, it could leak gas and cause potentially fatal injury over an area of the size of about two football fields, he said, adding that "this is all about trying to reduce the danger to human beings."
Other experts, however, said that they believed the heat of reentry would cause the tank to explode safely high in the air.
Cartwright said that two other Navy cruisers with backup missiles have been dispatched and that they could take additional shots at the satellite, if necessary. He said, however, that the window for shooting down the spacecraft is quite small.
The National Reconnaissance Office satellite lost contact with ground control soon after it was launched in December 2006. Never ordered to burn its maneuvering fuel, it still carries about 1,000 pounds of frozen hydrazine, a substance Cartwright said is "similar to chlorine or to ammonia in that when you inhale it, it affects your tissues in your lungs," adding: "It has the burning sensation. If you stay very close to it and inhale a lot of it, it could in fact be deadly."
The Columbia spacecraft, which broke apart and hit Earth in 2003, also contained a canister of hydrazine gas that landed intact in a Texas woodland. Columbia was at the end of its mission, however, and most of the hydrazine had burned.
Cartwright said that the Aegis missile system aboard the cruiser would fire an SM-3 missile with a heat-seeking nose that destroys its target by hitting it, not blowing it up. The missile, known as Block III, was developed primarily for intermediate missile defense against warheads coming in at low altitude. The Navy has spent the past three weeks modifying missile software normally set for hitting much higher targets, he said.
Asked whether the plan is really an attempt to test the Aegis system as an anti-satellite system -- which would be a very controversial step internationally -- Cartwright said the amount of special modifications being done to the programs used to guide the system would "not be transferable to fleet use."
He also rejected widely disseminated blog allegations that the destruction of the satellite had been planned to keep classified information aboard from landing in non-U.S. hands. Everything other than the gas container, he said, would be destroyed on reentry even without a missile strike.
Members of Congress were briefed on the plan yesterday, as were diplomats from other nations. House Armed Services Committee Chairman Ike Skelton (D-Mo.) said in a statement that "I attended a Congressional briefing this morning by the Department of Defense, and I am satisfied that the destruction of the malfunctioning satellite is the best option available to protect public safety."
"However, it should be understood by all, at home and abroad, that this is an exceptional circumstance and should not be perceived as the standard U.S. policy for dealing with errant satellites," he said. "The House Armed Services Committee will work closely with the Department of Defense and other concerned agencies to oversee the broader policy implications of this action in relation to our space assets."
Staff writers Karen DeYoung in Washington and Colum Lynch at the United Nations contributed to this report.