A missile launched last week successfully destroyed the fuel tank of an inoperable spy satellite, U.S. military officials said Monday.

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

The fuel tank was carrying about 1,000 pounds of frozen toxic hydrazine propellant. The tank likely would have survived re-entry had the satellite fallen to Earth. It could have dispersed potentially deadly fumes over an area the size of two football fields, officials said.

Hydrazine affects the lungs and is similar to chlorine or ammonia.

The Navy shot the satellite down about 10:30 p.m. ET Wednesday using a missile from the USS