Video of the mission shows an interceptor missile ascending atop a bright trail of burning fuel, and then a flash, a fireball, a plume of vapor.

The operation Thursday left a cloud of debris and little doubt that the missile had squarely hit its mark, a dying spy satellite in its final, declining orbits more than 130 miles, or 200 kilometers, above the Pacific Ocean.

A different kind of doubt still lingers, though, expressed by policy analysts, some scientists and not a few foreign powers, especially China and Russia.

Did the risk to people of a half-ton of frozen rocket fuel landing who knows where warrant such an extraordinary military operation? Or was it really designed to showcase America’s technical prowess? And could this really have been a test for a shadow program to develop a new anti-satellite capability, the same type of weapon that was the target of Washington’s criticism when China blew up a weather satellite last year?

Defense Secretary Robert Gates said at a press conference in Hawaii that he was prepared to share some details of the operation with China to alleviate that country’s concerns that the debris still may prove dangerous. Even as football-sized rubble began to re-enter the atmosphere, the military remained poised to respond to any problems that might emerge.

Senior military officials dismissed concerns among Chinese and Russian officials and some arms control analysts that the episode was really a test of missile defenses.

They pointed out that while the U.S. Navy’s SM-3 interceptor is an integral part of the military’s effort to defend against a limited ballistic missile attack, the three rockets picked for this task — only one was used — had to be completely reprogrammed in order to seek and strike a big, cold satellite in space, instead of a small, red-hot enemy warhead…

Tags: Space