Aegis: Not a Silver Bullet

May 18, 2010
David Wright
Former contributor

The analysis by George Lewis and Ted Postol of the test record of the Aegis SM-3 interceptor again shows a disturbing long-term pattern by the Missile Defense Agency (MDA) in which public relations trumps the reality of missile defense development. Lewis and Postol look at all 10 Aegis tests against unitary targets (those in which the warhead remains attached to the empty missile casing) that the MDA says were successful. The Lewis-Postol analysis finds that 8 or 9 of these 10 tests would likely not have destroyed the warhead. (This issue was also raised early in the SM-3 test program in a UCS analysis.)

This is important because the SM-3 test record has been touted as showing that the Aegis system is “proven” and can be the basis for an expanded missile defense system. Policymakers and military leaders need to have a better understanding of what the tests mean before they make decisions about the future of the Aegis missile defense system.

The SM-3 interceptor attempts to intercept a missile during its midcourse phase, after the missile has burned out and when it is traveling above the atmosphere. If the warhead is not detached from the now-empty missile body that contained the rocket fuel at launch, then the interceptor’s kill vehicle will see a large target, but the tests seem to show that it has trouble hitting the warhead part of that large target.

The physical issue here is that if the small kill vehicle hits an empty missile casing at hypervelocity speed, it is likely to punch through it like a bullet through an empty tin can (the speed of the kill vehicle is some 20 times the speed of a bullet). In doing so it will jar the missile body, but this jarring is unlikely to be sufficient to destroy a hardened warhead. Because a warhead is designed to survive the rigors of boost and reentry phases, it is necessarily hardened.

The most worrisome part of this revelation is that once again it calls into question how reliable the information is that policymakers and military leaders are getting from MDA. There continue to be troubling signs that they aren’t getting the real story. One such sign is President Obama’s reference last September to the Aegis system as “proven” when clearly it isn’t—even before you include the complication of countermeasures. (Like the U.S. ground-based anti-missile system, the SM-3 is inherently vulnerable to straightforward countermeasures like balloon decoys.)

A second high-profile example of this problem is the statement of General Cartwright, vice-chair of the Joint Chiefs of Staff, who told a Senate hearing last June that the odds of the U.S. ground-based missile defense system intercepting a North Korea missile are “ninety-plus percent.” The truth is that there is simply no technical basis for making such an assessment, since the tests that have been conducted are highly scripted, artificial, and do not represent real-world engagements.

Pursuing missile defense with misinformation is worse than just a boondoggle. If political and military leaders are being led to believe they have capabilities they in fact do not have, that can lead them to make bad, and potentially disastrous, decisions.

The Nobel-prize winning physicist Richard Feynman put it best in his commentary on the explosion of the Space Shuttle Challenger:

“For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled.”