By Dave Ahearn

Several critics recently assailed the U.S. move to use a Lockheed Martin [LMT] sea-based Aegis ballistic missile defense system and Raytheon [RTN] Standard Missile-3 interceptor to shoot down a dead/disabled intelligence satellite, saying the action impairs U.S. moral standing in opposing satellite destruction by other nations.

The critics also questioned whether the shoot-down was justified by a sufficient probability that a tank full of 1,000 ponds of toxic hydrazine fuel on the out-of-control satellite would survive reentry into the atmosphere and strike a populated area, injuring or killing humans.

However, the critics didn’t say that the failed satellite and its hydrazine fuel tank posed no threat to humans.

As well, the critics didn’t dispute Pentagon estimates that debris caused by demolishing the satellite with a U.S. ballistic missile defense system would come down safely into the atmosphere and burn up during reentry, with most of the debris de-orbiting within hours and the remainder within months at most.

And the critics didn’t argue that the United States was more open in giving prior public announcements and warnings of the shoot-down than China was before it abruptly sent a ground-based interceptor missile to destroy an aging Chinese satellite in January last year.

Rather, the critics said the Pentagon should release details of risk assessments and probability figures that went into the decision to shoot down the ailing U.S. intelligence satellite, which never functioned after it was launched into orbit in 2006.

Separately, however, a military officer involved with the shoot-down said that regardless of the percentage probability that the hydrazine tank would survive reentry and strike a populated area, so long as there was any chance of endangering humans–and there was–then the satellite shoot-down was a moral imperative.

Two of the critics were Geoffrey Forden, senior research associate with the Security Studies Program at the Massachusetts Institute of Technology, and Jeffrey G. Lewis, director of the Nuclear Strategy and Nonproliferation Initiative with the New America Foundation. They spoke to journalists at a luncheon of the Center for Media and Security at the American Association for the Advancement of Science in Washington, D.C., last week.

Also last week, many of the same views were expressed separately by another critic, Michael Krepon, co-founder of the Henry L. Stimson Center, a non-partisan defense-oriented Washington think tank. He also is a diplomat scholar at the University of Virginia. Krepon wrote his views in a white paper titled “After the ASAT Tests” that was published by the Stimson Center.

For the other side of the issue, Space & Missile Defense Report, sister publication of Defense Daily, interviewed Col. Mike Carey, deputy of J-3 Operations with the U.S. Strategic Command at Offut AFB, Neb.

Carey’s key point is that the United States had to take action to protect innocent humans from harm, and demolishing the dead intelligence satellite was the only way of assuring that, since military officials couldn’t take the customary step of commanding the satellite to reenter the atmosphere and plunge to its demise in an unpopulated area (because the satellite wasn’t functioning).