WASHINGTON — The Pentagon says a U.S. missile smashed a disabled spy satellite that was headed for Earth and the military is tracking the debris as it falls over the Atlantic and Pacific oceans.
Marine Gen. James Cartwright, vice chairman of the Joint Chiefs of Staff, told a Pentagon press conference Thursday that he couldn't rule out that hazardous material would fall to the earth.
But he says so far officials have tracked "nothing larger than a football."
Cartwright says officials also "have a high degree of confidence" — though are not ready to say for sure — that the missile launched from a Navy ship near Hawaii struck the satellite's fuel tank. Officials said the toxic hydrazine fuel in the tank would have caused a hazard had it fallen to earth.
Destroying the satellite’s onboard tank of about 1,000 pounds of hydrazine fuel was the primary goal, and a U.S. official earlier told NBC News that it "looks like the tank was hit."
"It is still going to take some more analysis" to determine what happened to the fuel, but early indications were positive, the official said.
Defense Secretary Robert Gates ordered the shootdown, which came late Wednesday as he began an eight-day, around-the-world trip on which he likely will face questions about the mission.
The elaborate intercept may trigger worries from some international leaders, who could see it as a thinly disguised attempt to test an anti-satellite weapon — one that could take out other nations' orbiting communications and spy spacecraft.
China expresses concern
Within hours of the reported success, China said it was on the alert for possible harmful fallout from the shootdown and urged Washington to promptly release data on the action.
“China is continuously following closely the possible harm caused by the U.S. action to outer space security and relevant countries,” Foreign Ministry spokesman Liu Jianchao said at a news conference in Beijing. “China requests the U.S. to fulfill its international obligations in real earnest and provide to the international community necessary information and relevant data in a timely and prompt way so that relevant countries can take precautions.”
While Pentagon officials stressed that the satellite strike was a one-time incident, it certainly will spin off massive amounts of data and research that can be studied by the military as it works to improve its missile defense technologies.
The USS Lake Erie, armed with an SM-3 missile designed to knock down incoming missiles — not orbiting satellites — launched the attack at 10:26 p.m. ET (0326 GMT Thursday), according to the Pentagon. It hit the satellite as the spacecraft traveled at more than 17,000 mph (27,000 kilometers per hour).
The shootdown, which was approved by President Bush, is seen by some as blurring the lines between defending against a hostile long-range missile and targeting satellites in orbit.
Because the satellite was orbiting at a relatively low altitude at the time it was hit by the missile, debris will begin to re-enter the Earth's atmosphere immediately, a Pentagon statement said.
Burn before re-entry?
"Nearly all of the debris will burn up on re-entry within 24-48 hours and the remaining debris should re-enter within 40 days," it said.
The use of the Navy missile amounted to an unprecedented use of components of the Pentagon's missile defense system, designed to shoot down hostile ballistic missiles in flight — not kill satellites.
The goal in this first-of-its-kind mission for the Navy was not just to hit the satellite but to obliterate the fuel tank.
U.S. officials have said the fuel would pose a potential health hazard to humans if it landed in a populated area. Although the odds of that were small even if the Pentagon had chosen not to try to shoot down the satellite, it was determined that it was worth trying to eliminate even that small chance.
Officials said it might take a day or longer to know for sure if the toxic fuel was blown up.
The government has organized hazardous materials teams to be flown to the site of any dangerous or otherwise sensitive debris that might land in the United States or elsewhere. The operation was so extraordinary, with such intense international publicity and political ramifications, that Gates — not a military commander — made the final decision to pull the trigger.
Gates had arrived in Hawaii less than two hours before the missile was launched. His press secretary, Geoff Morrell, said Gates had a conference call during his flight with Air Force Gen. Kevin Chilton, head of Strategic Command, and Cartwright, vice chairman of the Joint Chiefs of Staff. They told him that “the conditions were ripe for an attempt, and that is when the secretary gave the go-ahead to take the shot, and wished them good luck,” Morrell said.
At 10:35 p.m. EST, Gates spoke to both generals again and “was informed that the mission was a success, that the missile had intercepted the decaying satellite, and the secretary was obviously very pleased to learn that,” said Morrell.
Adm. Timothy J. Keating, chief of U.S. Pacific Command, told reporters shortly before the strike that he made calls to a number of international leaders to alert them to the mission. He said none said they had concerns, but he acknowledged he did not speak to the Chinese.
China and Russia both expressed concerns about the shootdown in advance, saying it could harm security in outer space.
The U.S. government organized hazardous materials teams, under the code name "Burnt Frost," to be flown to the site of any dangerous or otherwise sensitive debris that might land in the United States or elsewhere.
High seas in the north Pacific had threatened to postpone the launch as the USS Lake Erie prepared a three-stage missile. Beyond a certain point, rough seas can interfere with the cruiser's launch procedures.
Early in the day, a senior military officer said it did not look as if the weather would be good enough. That was shortly after the space shuttle Atlantis landed, removing the last safety issue for the military to begin determining the best moment for launch.
The Centers for Disease Control and Prevention issued a health bulletin saying that the health risk from satellite debris was considered to be low. "However, CDC is encouraging health officials and clinicians to review information about the health effects related to hydrazine to prepare in case their communities are affected by satellite debris."
The government issued notices to aviators and mariners to remain clear of a section of the Pacific Ocean beginning at 10:30 p.m. EST Wednesday.
Much of the equipment used in the satellite shootdown was part of the Pentagon's missile defense system, a far-flung network of interceptors, radars and communications systems designed primarily to hit an incoming hostile ballistic missile fired at the United States by North Korea. The equipment, including the Navy missile, has never been used against a satellite or other such target.
The three-stage Navy missile has chalked up a high rate of success in tests since 2002 — in each case targeting a short- or medium-range missile. A hurry-up program to adapt the missile for this anti-satellite mission was completed in a matter of weeks; Navy officials say the changes will be reversed once this satellite is down.
Left alone, the satellite would have been expected to hit Earth during the first week of March. About half of the 5,000-pound spacecraft would be expected to survive its blazing descent through the atmosphere and would scatter debris over several hundred miles.
The Associated Press and NBC News' Jim Miklaszewski contributed to this story.