How Do Missile Defense Systems Work?

You probably know that the US has a missile defense system, and just a thought makes you feel (relatively) safe and comfortable here in the states. But do you know how these systems work? Or how effective can they be? They are not an impenetrable shield as you might think.

North Korea recently tested another missile that convinced experts that the entire continental United States is now within range of its intercontinental ballistic missiles (ICBMs) , provided the missile carries a small payload. This draws more attention to US missile defense systems and whether they actually work. After an allegedly unsuccessful attempt to defend Saudi Arabia with the US-supplied Patriot missile system, people are beginning to wonder, “Are we safe?” But before we get into how effective they are, let’s talk about how they work.

How missile defense systems work

The basic functions of a missile defense system are simple – you use ballistic missiles to shoot down other missiles – but a lot happens during this process. Here’s a game-by-play in how missile defense systems such as the U.S. Midline Ground Defense (GMD) and the U.S. Navy’s SM-3 Aegis missile defense system must stop an approaching ICBM like the one recently in North Korea. checked:

1. The threat rocket has been launched.
2. Satellites using infrared technology and radar detect the launch and track the trajectory of the rocket.
3. The threat missile fires a warhead and decoys (known as a “threat cloud”).
4. Land-based and sea-based radar continuously monitors the threat cloud in an attempt to identify the warhead (where the payload is located).
5. The missile defense system launches an interceptor missile.
6. The interceptor’s payload, the “destruction vehicle”, is separated from the missile body.
7. The assassin machine detects a threat cloud and attempts to intercept the warhead high in the atmosphere.

If all goes according to plan, the payload will be destroyed in space before reaching its target below.

These systems, however, differ from the end-phase missile defense systems Patriot , Arrow, and Iron Dome in the atmosphere (talk patter). These systems work in a similar way, using radar and atmospheric guidance for tracking, but are only designed to intercept short- to medium-range missiles that travel at much slower speeds and lower altitudes than ICBMs. They only cover areas tens of kilometers across, so it’s nice to have them on hand as a backup system for staging systems, but they’re probably more useful in regions like South Korea and Japan than here in the states (provided that the launch will take place. from North Korea). The system of protection of end altitudinal zones (THAAD) US Army is classified as a system terminal phase, but it has a few tricks up his sleeve. It works more like a middle course system and can destroy targets by direct collision in the upper atmosphere or higher.

So how effective are they?

When it comes to protecting ICBMs, we have no idea. Maybe they will work, maybe they won’t. Why? As George N. Lewis , physicist and senior fellow at the Institute for Peace and Conflict at Cornell University, explains in his article “The Effectiveness of Missile Defense,” there is no real experience with medium-range ballistic weapons. missile defense. Our GMD systems have, of course, been testedand proven to be successful , but current tests of interception interception protection are few and far between, and usually represent a demo with a detailed scenario that reflects more of the reliability of these systems, rather than their actual performance in a scenario from the real the world.

You see, attacking enemies can use countermeasures when launching a rocket. These countermeasures include mechanisms, such as traps or a cooling jacket , designed to confuse or disrupt the protection system so that it fails. We do not test our defense systems with this in mind, even though the technology for developing such countermeasures is widely known. Our GMD system is very effective at detecting missile launches and tracking multiple targets over long distances, but it is not very good at understanding which objects are warheads and which are traps. Honolulu’s primary discrimination sensor, the Maritime X-Band Radar (SBX) , has significant operational limitations . Nonetheless, the US National Academy of Sciences’ book Understanding Missile Defense suggests that theoretically possible countermeasures are not always easy to apply, citing the US and UK’s own experiences with developing such penetration devices during the Cold War. It is also likely that such countermeasures will reduce the payload, range, or reliability of the missile.

However, while our GMD defense system is theoretically capable of protecting all fifty states from ICBM missile attack, it is still largely untested against real-world threats, and its test results are not entirely encouraging:

As you can see, the GMD system only works half the time and it doesn’t seem to be improving. Naval Aegis missile defense systems showed the best results in their tests:

Not only do they have higher success rates, they have been tested both day and night; tested against short, medium and medium range targets; tested against both intact missiles and individual warheads; and has been tested against two simultaneous targets. Unfortunately, Lewis says their low speed prevents them from covering enough territory to be useful as a defense here in their homeland. Next year, the US hopes to deploy new SM-3 Block IIA interceptor missiles that could possibly get the job done ( although they also failed in recent tests in June ).

So are we protected from a missile strike here in the US? It’s hard to say, but we’re probably not as safe as you think. The US military has repeatedly stated that their successes are much higher than they actually are. During the Gulf War, the US military claimed a 96% success rate against Iraqi modified Scud missiles and then reduced that requirement to 61%. Further analysis by experts showed that the success rate was very low and possibly 0% . Following the recent missile strike in Saudi Arabia, President Trump said :

“Our system shot down a missile from the air … That’s how good we are. Nobody does what we do and now we sell it all over the world. “

But further analysis of the evidence suggests that the Patriot missile system failed , and that the warhead nearly hit the airport it was targeting, where people heard and witnessed the explosion. Regarding our GMD defenses in the rear, Lewis notes that US officials have also exaggerated these success rates :

However, statements by US officials suggest that a system designed to counter nuclear-armed missiles can be considered effective if its predicted effectiveness exceeds approximately 90%. On June 16, 2009, just a week after Defense Secretary Robert M. Gates told Congress that the current missile defense system is “fully adequate to protect us from the North Korean threat,” said General James Cartwright, deputy chairman of the Joint Chiefs of Staff. … , told the Senate committee that he rated the effectiveness of the missile defense system against the North Korean missile as “ninety percent plus.” A year later, amid continuing statements by US officials about their confidence in the effectiveness of the GMD system, MDA Director Lt. Gen. Patrick O’Reilly told the House Armed Services Committee that the likelihood of the system being able to counter a single ICBM launched from with help Iran “will survive the nineties.”

But here’s the catch: even if GMD and Aegis BMD systems achieve 80% to 90% success in the future, it may still not be enough. After all, a failure rate of 10% to 20% is insufficient against a small barrage of nuclear missiles. As the United States has proven in the past, one person is enough to destroy a territory. But to improve this protection, and even to go this far, will require a lot more testing (ideally testing in a real-world scenario), and this requires more attention and money. These tests are not cheap (recent testing in May cost $ 244 million), but they are necessary if we are going to rely on these systems. Although, perhaps we are better off trying to avoid any conflicts when we need such protection from the beginning.

More…