WASHINGTON — The missile that took down a disabled spy satellite last week almost certainly destroyed a tank filled with potentially harmful hydrazine fuel, the Pentagon said yesterday.

"By all accounts this was a successful mission," Gen. James Cartwright, vice chairman of the Joint Chiefs of Staff, said in a statement. "From the debris analysis, we have a high degree of confidence the satellite's fuel tank was destroyed and the hydrazine has been dissipated."

The conclusion was based on a study of the debris field, the statement said. The Pentagon also has video shot from the missile warhead as it approached the satellite, McClatchy Newspapers reported, but that video is not being released.

Soon after the satellite was hit, the Pentagon made available a video taken from a different vantage point showing an explosion as the anti-ballistic missile struck the descending satellite.

The 5,000-pound satellite was struck by a Standard Missile-3, launched from the Pearl Harbor-based Navy cruiser USS Lake Erie in the North Pacific, as the satellite orbited about 150 miles above Earth. The Joint Space Operations Center at Vandenberg Air Force Base, Calif., is tracking fewer than 3,000 pieces of debris from the strike, all smaller than a football, the Pentagon said. Most of the debris already has entered the Earth's atmosphere and burned up, or will do so soon.

The Pentagon statement said there have been no reports of debris landing on Earth and "it is unlikely any will remain intact to impact the ground."

President Bush ordered the satellite destroyed after advisers told him the hydrazine-filled fuel tank could make it through the atmosphere intact, and that people could be harmed if it landed near them and they lingered in the area.

Skeptics say that the administration had other possible reasons to shoot down the satellite — to destroy secret equipment onboard, to test ground-based missiles against an object coming in from space, or to send a message to China, which conducted an anti-satellite test in January 2007.

Before the missile strike, scientists at the Massachusetts Institute of Technology calculated that the fuel tank would almost certainly break apart as it passed through the atmosphere.