The test ostensibly proved that, after decades of development and dozens of failed tests costing hundreds of billions of dollars, the United States finally has the ability to defend against nuclear-tipped intercontinental ballistic missiles—like the kind North Korea has threatened to launch against American cities.
Be skeptical. In fact, the test—while not exactly rigged—might not have been very realistic. If so, it doesn't really matter that it succeeded. If North Korea were to develop and launch a rocket at Los Angeles or San Francisco, the Pentagon might still be powerless to stop it. "Even a successful test will not demonstrate that the system is effective," Greg Thielmann, a former State Department missile expert, told Motherboard on the eve of the interception.
The test of the $40-billion Ground-based Midcourse Defense system, or GMD, involved two rockets. One, a target that the Missile Defense Agency loosely modeled on North Korea's Taepodong ballistic missile. The other, a three-stage interceptor missile with a so-called "kill vehicle"—in essence, a non-explosive warhead—at its tip.
The GMD is the only major system the Pentagon is developing to defend against ICBMs, the heaviest, fastest-flying nuclear-tipped rockets that possess true, intercontinental range. The US military possesses several kinds of weapons—including lasers, guns and missiles—that can shoot down smaller, slower, shorter-range rockets.
The target in the May 30 test blasted off from a military base at Kwajalein Atoll in the mid-Pacific and arced toward the US West Coast. Sensors including a giant floating radar detected the target rocket. Missileers at Vandenberg Air Force Base in California quickly fired an interceptor missile, one of 36 installed at Vandenberg and a separate facility in Alaska.
The kill vehicle separated from its boosters and struck the target missile. "Although this was a developmental test, this is exactly the scenario we would expect to occur during an actual operational engagement," Admiral James Syring, head of the Missile Defense Agency, told reporters on May 31.
But Syring declined to say how fast the target rocket was traveling. "I can't go into the threat characteristics of the target, but I can tell you that it flew at a higher altitude and a longer range and a higher velocity than any other target we've flown to date," Syring said.
The target's velocity is a critical detail. The faster the rocket, the harder it is to shoot down. It's not for no reason that, in eight of 18 tests since 1999, GMDs have missed their targets. Intercepting an ICBM is like "hitting a bullet with a bullet," Syring said.
Laura Grego, a missile expert with the Union of Concerned Scientists based in Massachusetts, examined the distances the two test rockets were expected to travel—and how quickly—and, on May 29, concluded that the target rocket would probably be significantly slower than an ICBM launched from North Korea would be.
A North Korean ICBM targeting Los Angeles would likely reach a velocity of 6.7 kilometers per second. The target in the May 30 test probably maxed out at 5.9 kilometers per second, if not slower, Grego asserted.
Syring shot back against critics. "I don't want you to walk away to think that it was not a realistic test scenario," he told reporters. But the data that might back up Syring's claim—or, alternatively, prove Grego's own claim—is classified.
In any event, Thielmann told Motherboard the test itself wouldn't deter Pyongyang. "I doubt very much that North Korea would be dissuaded from its current nuclear and missile development track by a successful US test."
The only way we'll ever know for sure whether the Pentagon's missile shield actually works … is for North Korea or some other rogue state to fire an actual ballistic missile at an American city.
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