Ballistic Missile Defenses - Effectiveness and Reliability

[The Deterrent]

Ballistic Missile Defenses - Effectiveness and Reliability


Ballistic Missile Defenses (BMDs) are used for intercepting hostile ballistic missiles.Interception might be by
1. Anti-ballistic missiles (ABMs)
2. Directed-energy weapons such as lasers
3. Space-based anti-ballistic system.

Interception might occur near the :

1. launch point (boost phase),
2. during flight through space (mid-course phase) or
3. during atmospheric descent (terminal phase).

A. Anti-Ballistic Missiles

These are the guided SAMs used to intercept Ballistic missiles.They are majorly classified into 2 types:

Tactical ABMs

Tactical ABMs are generally designed to target SRBMs and MRBMs.Many short-range tactical ABM systems are currently operational, and three are most known:
1. U.S. Army Patriot
2. U.S. Navy Aegis combat system
3. U.S. Army THAAD
4. Israeli Arrow missile.

In general short-range tactical ABMs cannot intercept ICBMs, even if within range. The tactical ABM radar and performance characteristics do not allow it, as an incoming ICBM warhead moves much faster than a tactical missile warhead. However it is possible the better-performance Terminal High Altitude Area Defense missile could be upgraded to intercept ICBMs.

Criticism on Patriot SAM

The Patriot antiaircraft missile was the first deployed tactical ABM system, although it was not designed from the outset for that task and consequently had limitations. It was used during the 1991 Gulf War to attempt to intercept Iraqi Scud missiles. Post-war analyses show that the Patriot was much less effective than initially thought because of its radar and control system's inability to discriminate warheads from other objects when the Scud missiles broke up during reentry.

Criticism on Arrow ABM

A criticism of the concept of missile defense for Israel was aired by Dr. Reuven Pedatzur in a comprehensive study published in 1993 by the Jaffe Center for Strategic Studies. The arguments made in the study conformed to the opinions of numerous defense officials and analysts, and echoed many of the arguments made by the Strategic Defense Initiative critics in the United States.

Pedatzur argued that it was exceedingly simple to fool an Arrow-type defensive system with simple, cheap, and easily installed countermeasures, which would render the Arrow system ineffective.

He further argued that even if effective against missiles with conventional, chemical or biological warheads, the Arrow would not be relevant against future threats of missiles with nuclear warheads, since it would never be able to supply hermetic defense and the impact of even a single nuclear warhead in Israel's densely populated urban area would be an existential threat to Israel.

Counter-ICBM ABMs

There are only two systems in the world that can intercept ICBMs. Besides them, many smaller systems exist (tactical ABMs), that generally cannot intercept intercontinental strategic missiles, even if within range—an incoming ICBM simply moves too fast for these systems.

1. The Russian A-35 anti-ballistic missile system for defense of Moscow was established in 1971, has been improved since, and is still active. Presently it is called A-135 and it uses two missile types, Gorgon and Gazelle. They are, somewhat surprisingly, armed with nuclear warheads themselves.

2. The U.S. Ground-Based Midcourse Defense (GMD) system has recently reached initial operational capability. Instead of using an explosive charge, it launches a kinetic projectile. The system is a dual purpose test and interception facility in Alaska, and in 2006 was operational with a few interceptor missiles. The Alaska site provides more protection against North Korean missiles or accidental launches from Russia or China, but is likely less effective against missiles launched from the Middle East. The current GMD system has the more limited goal of shielding against a limited attack by a rogue state.

Counter measures against Long Range ABMs

1. Decoys

Decoys such as balloons and chaff are included in the counter-measures suite of Modern ICBMs.They not only disrupt the target tracking,but also multiply the targets to be intercepted,as it is very difficult to distinguish between real warheads and decoys.

An April 2000 study by the Union of Concerned Scientists and the Security Studies Program at the Massachusetts Institute of Technology concluded that “Any country capable of deploying a long-range missile would also be able to deploy countermeasures that would defeat the planned NMD system.” Countermeasures studied in detail were bomblets containing biological or chemical agents, aluminized balloons to serve as decoys and to disguise warheads, and cooling warheads to reduce the kill vehicle’s ability to detect them.

In April 2004, a General Accounting Office report concluded that “MDA does not explain some critical assumptions—such as an enemy’s type and number of decoys—underlying its performance goals.” It is recommended that “DOD carry out independent, operationally realistic testing of each block being fielded” but DOD responded that “formal operational testing is not required before entry into full-rate production.”

2. MIRVs

MIRVs reduce the effectiveness of an anti-ballistic missile system that relies on intercepting individual warheads. While a MIRV attacking missile can have multiple (3–12 on United States missiles and 3-10 on Russians) warheads, interceptors may have only one warhead per missile. Thus, in both a military and an economic sense, MIRVs render ABM systems less effective, as the costs of maintaining a workable defense against MIRVs would greatly increase, requiring multiple defensive missiles for each offensive one. Decoy reentry vehicles can be used alongside actual warheads to minimize the chances of the actual warheads being intercepted before they reach their targets. A system that destroys the missile earlier in its trajectory (before MIRV separation) is not affected by this but is more difficult, and thus more expensive to implement.

3. Sub-munitions

These may consist of large number of chemical or biological
weapon (CBW) submunitions. Fractionated CBW payloads pose one of the
most difficult responsive threats to theater missile defenses because tens or hundreds of bomblets may be deployed on each missile. CBW submunitions are more challenging for long-range ballistic missiles because it is difficult to provide sufficient thermal protection to prevent CBW agents from denaturing due to reentry heating. CBW submunitions also are difficult to detect and track because of their small radar cross section and, if tracked, may be difficult to intercept with hit-to-kill interceptors after their release because of
their small size.

4. Maneuverable Re-entry Vehicle (MaRV)

MaRVs are generally equipped with terminal correction systems i.e. a small motor or thrusters are attached with the RV,which enhance its accuracy.They also be used to dodge an ABM by continuously changing flight path.

The rocket-nozzle control system allows the missile to change its trajectory several times during re-entry and even terminal phase, effectively preventing pre-calculated intercept points of radar systems - which is a method nearly all ABM systems use these days.

B. Directed Energy Weapons / Lasers

Lasers are being employed to take out ballistic missiles,primarily in the boost phase.The currently deployed Laser based interceptor is the USAF YAL-1 Airborne Laser

The Boeing YAL-1 Airborne Laser Testbed, (formerly Airborne Laser) weapons system is a megawatt-class chemical oxygen iodine laser (COIL) mounted inside a modified Boeing 747-400F. It is primarily designed as a missile defense system to destroy tactical ballistic missiles (TBMs), while in boost phase.

The ABL was designed for use against tactical ballistic missiles (TBMs). These have a shorter range and fly more slowly than ICBMs. The MDA has recently suggested the ABL might be used against ICBMs during their boost phase. This could require much longer flights to get in position, and might not be possible without flying over hostile territory. Liquid-fueled ICBMs, which have thinner skins, and remain in boost phase longer than TBMs, might be easier to destroy.

If the ABL achieves its design goals, it could destroy liquid-fueled ICBMs up to 600 km away. Tougher solid-fueled ICBM destruction range would likely be limited to 300 km, too short to be useful in many scenarios, according to a 2003 report by the American Physical Society on National Missile Defense.

Criticism

Secretary of Defense Gates said that "I don't know anybody at the Department of Defense, Mr. Tiahrt, who thinks that this program should, or would, ever be operationally deployed. The reality is that you would need a laser something like 20 to 30 times more powerful than the chemical laser in the plane right now to be able to get any distance from the launch site to fire.

"So, right now the ABL would have to orbit inside the borders of Iran in order to be able to try and use its laser to shoot down that missile in the boost phase. And if you were to operationalize this you would be looking at 10 to 20 747s, at a billion and a half dollars apiece, and $100 million a year to operate. And there's nobody in uniform that I know who believes that this is a workable concept."

C. Space-based Anti-ballistic systems

Using orbital launchers to provide a reliable boost-phase defense against liquid-fueled ICBMs is not likely, as it was found to require at least 700 large interceptors in orbit. Using two or more interceptors per target, or countering solid fueled missiles, would require many more orbital launchers. The old Brilliant Pebbles project—although it did not applied to boost phase—estimated the number at 4,000 smaller orbital launchers.

Boost-phase defense

As of boost-phase interceptions, these would be desired as an initial layer of defense. It is the only layer that can cost-effectively destroy MIRV missiles.

Currently only Aegis has a possible boost-phase capability, but—in case of SM2—it needs to be within 40 km of a launch point. This is acceptable for SLBMs, but not likely for land-based intercontinental ballistic missiles (ICBMs).

Boost-phase defense against solid-fueled ICBMs

Boost-phase defense is significantly harder against the current solid-fueled ICBMs, because their boost phase is shorter. Current solid-fueled ICBMs include Russian Topol, and Chinese DF-31 and DF-41, along the US Minuteman and Trident.

There is no theoretical perspective for economically viable boost-phase defense against the latest solid-fueled ICBMs, no matter if it would be ground-based missiles, space-based missiles, or airborne laser (ABL).

Boost-phase defense against older ICBMs

A ground-based boost-phase defense might be possible, if goals were somewhat limited: to counter older liquid-fuel propelled ICBMs, and counter simple solid-propellant missiles launched from "easier" locations (such as North Korea).

The airborne laser (ABL) is possibly capable of intercepting a liquid fuel missile if within 600 km from a launch point.


General countermeasures against BMDs

Countermeasures to ballistic missile defenses can be grouped into the following
categories:
1. Circumvention (i.e., using delivery means other than ballistic missiles)
2. Defense suppression (i.e., attacking the defense directly)
3. Saturation (using a large number of ballistic missiles or decoys)
4. Qualitative improvements in the offense (e.g., reduced missile or warhead signatures).

References

Report of the American Physical Society Study Group on Boost-Phase Intercept System for National Missile Defense: Scientific and Technical Issues, Rev. Mod. Phys. 76, S1 2004. David K. Barton, Roger Falcone, Daniel Kleppner, Frederick K. Lamb, Ming K. Lau, Harvey L. Lynch, David Moncton, David Montague, David E. Mosher, William Priedhorsky, Maury Tigner, and David R. Vaughan.

Center for Defense Information IFT-9: A Questionable Success For Missile Defense. Weekly Defense Monitor, Volume 6, Issue #36 October 24, 2002.

Countermeasure Doubletalk / UCS Overstates Ease of Defeating Missile Defense Scott McMahon, Stanley Orman, and Richard Speier, Defense News, June 19, 2000 p.19.

Union of Concerned Scientists/MIT Security Studies Program. Countermeasures: A Technical Evaluation of the Operational Effectiveness of the Planned U.S. National Missile Defense System(Executive Summary and full text)(PDF). UCS-MIT Study, A.M. Sessler (Chair of the Study Group), J.M. Cornwall, R. Dietz, S.A. Fetter, S. Frankel, R.L. Garwin, K. Gottfried, L. Gronlund, G.N. Lewis, T.A. Postol, and D.C. Wright, April 2000.

PBS. The NewsHour with Jim Lehrer. A VIABLE DEFENSE?. January 28, 1999.

Note : This article is based on exempts taken from Wikipedia and the sources mentioned above.

 

[Chogy]

Good article. The technology is progressing, and we will see these become more effective. We'll also see counters to them on the missiles themselves. It's a basic back-and-forth game, much like armor vs. armor-piercing ordnance.

 

[The Deterrent]

Good article. The technology is progressing, and we will see these become more effective. We'll also see counters to them on the missiles themselves. It's a basic back-and-forth game, much like armor vs. armor-piercing ordnance.

Yes...but I suppose that BMDs would never be able to fully take over Ballistic missiles,specially ICBMs...