A missile launched from a Navy ship successfully struck a dying U.S. spy satellite passing 130 miles over the Pacific Ocean on Wednesday, a defense official said.

The Pentagon said it should know in the next 24 hours whether the spacecraft's fuel tank was destroyed as planned. The fuel tank contains approximately 1,000 pounds of hydrazine, a hazardous fuel that could pose a danger to people, before it entered into Earth's atmosphere.

"We are very confident that we hit the satellite and we have a high degree of confidence that we hit the tank," said Gen. James Cartwright, the vice chairman of the Joint Chiefs of Staff, said Thursday morning. "We have a cloud that appears to be hydrazine. We're looking for more refinement of the data."

The missile-strike happened just after 10:30 p.m. EST.

Pentagon officials said the USS Lake Erie fired a single modified tactical Standard Missile-3, hitting the satellite approximately 133 nautical miles over the Pacific Ocean as it traveled in space at more than 17,000 mph.

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.

Due to the relatively low altitude of the satellite at the time of the engagement, debris began to re-enter the earth's atmosphere immediately after the missile hit. 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.

Cartwright said that of the debris that had been tracked, officials had seen nothing larger than the size of a football.