Why is military action against North Korea not on the table? How effective are the US installed Missile defenses in South Korea?
By Krishna Santos
Standard Missile SM-3 interceptor
First let us see what Short, Medium & Intermediate Range Ballistic Missile are:
Short Range Ballistic Missile (SRBM) : Range 👉(300 km to 1,000 km)
Medium Range Ballistic Missile (MRBM) : Range 👉(1,000 km to 3,500 km)
Intermediate Range Ballistic Missile (IRBM) : Range 👉(3,500 km to 5,500 km)
The Earth’s atmosphere starts from 140km above the earth’s surface. Shorter range ballistic missiles stay within the Earth’s atmosphere. North Korea has 800+ short-range ballistic missiles.
To defend against the North Korean missile force, South Korea currently has three layered Ballistic Missile Defence,
1) Patriot (PAC-3) to counter short-range missile threats
2) THAAD for Short and Medium range threats
3) Aegis (SM-3) for Medium and Intermediate-range ballistic missile threats
Three layered Missile defense Aegis, THAAD & PAC-3
Aegis BMD (ship based)👉 240km (Exo-atmospheric interception)
THAAD Interception Altitude 👉40km -150km (Endo & Exo atmospheric interception)
Patriot (PAC-3) Interception Altitude 👉 25km (Endo-atmospheric interception).
Patriot Advanced Capability (PAC-3)
Patriot was used initially as an anti-aircraft system, i.e, in Air defense role, but during 1988, it was upgraded to provide limited capability against tactical ballistic missiles as PAC-1 (Patriot Advanced Capability-1). The most recent upgrade, called PAC-3 is designed to exclusively engage ballistic missile warheads.
PAC-3 intercepts short- and medium-range missiles by colliding with the threatening missile or warhead at low-altitudes (less than 25 km, or endoatmospheric) and at short distances (35-40 km or less) from its location.
Patriot missile defenses have been tested in combat, taking out short-range ballistic missiles during the 1991 Gulf War and the 2003 invasion of Iraq. PAC-3 incorporates “hit-to-kill” technology, destroying ballistic-missile warheads though direct impact rather than proximity explosion like in earlier PAC-2 used in Air defense role.
Though there were stories about how the Patriot wasn’t that great back in ‘92 and achieved only 10% kill rate, after many upgrades to flight software, radar and missile design, the current generation Patriot is considered the most effective anti-ballistic missile system against a limited number of short-range missiles.
The PAC-3 system is intended to provide protection for key installations such as Airfields, Ports, Military Command Centers, Critical Infrastructure. PAC-3 forms ‘lower-tier’ defense system as it destroys targets at low altitudes.
Terminal High Altitude Area Defense (THAAD)
THAAD is particularly well-suited to intercept and destroy short, medium, and intermediate-range ballistic missiles in their terminal phase or re-entry phase. It is able to intercept incoming missiles inside and just outside the earth’s atmosphere at altitudes of 40-150Km. It covers the area above Patriots, but below Aegis BMD (Ballistic Missile Defense).
THAAD consists of five primary components: Interceptor missiles, launch canisters, AN/TPY-2 phased array radar, a fire-control unit, and support equipment—including a power-generation and cooling units. These can detect and track targets at a range of about 1000 km.
A single THAAD battery consists of six launcher vehicles, each launcher vehicle equipped with eight missiles that are mounted on a truck (6×8=48 missiles), AN/TPY-2 ground-based radar and associated command and communications facilities.
Single THAAD launcher firing interceptor missile
New South Korean President Moon Jae-in had held up the placement of a full battery of six THAAD launchers after two launchers were installed. On Sep 7, 2017, South Korea deploys four remaining THAAD system launchers after North Korea detonated a powerful nuclear device on Sep 3, 2017.
A single THAAD battery holds a limited number of ready-to-launch interceptors, likely ranging from 48 to 96. Spare interceptors can be stockpiled, though at great expense. This implies that one THAAD battery can defend against 20 and 50 attacking missiles if two interceptors are assigned to each incoming warhead. If additional interceptors are available, the launch canisters can be reloaded within an hour or so. However, there is no assurance that North Korea would pause firing its missiles to allow THAAD to reload.
Failure Rate of THAAD
THAAD system failed six tests in the 1990s. Though it boasts an 11-for-11 success rate since 2006, those tests are heavily scripted to ensure THAAD succeeds.
To date, THAAD has not been independently tested against more than two ballistic missiles. The test on Sep 10, 2013, THAAD intercepted only 1 medium-range ballistic missile out of 3. On Nov 1, 2015, there were two intercept attempts by THAAD, both reportedly successful.
Here’s a link for test reports:
A quick look at the THAAD flight test results shows that the bulk of its testing has been against short-range targets.
We don’t know whether THAAD can intercept three or more incoming missiles, Meanwhile, it is estimated that North Korea has around 1,000 ballistic missiles. And if North Korea fires salvo or dozens of missiles in series carrying chemical or nuclear weapons, even one missile that missed/evaded the defense systems would cause catastrophic damage.
Aegis BMD (ship based)
The Aegis BMD is an upper-tier (exo-atmospheric) ballistic missile defense which provides warships with the capability of intercepting and destroying short to intermediate-range ballistic missiles in the midcourse and terminal phases of the missile flight. When we park an Aegis destroyer or cruiser off the coast, that means we’re also placing these in range.
Aegis, like all missile defense systems, is made up of three basic components: sensors (Radar), interceptor missile SM-3, and command and control.
It uses primary radar AN/SPY-1D which provides 360° coverage and automatically tracks more than 100 targets at one time. It can detect a golf ball-sized target at ranges in excess of 165 km.
It uses 3 variants of standard missile SM-3 for intercepting medium and intermediate-range ballistic missiles. SM-3 missiles have much longer range than the Patriot and can engage exo-atmospheric targets including satellites. In Feb 2008, the Aegis BMD successfully destroyed a non-working spy satellite. Intercepts have been successfully tested up to around 250km altitude.
The three missile variants are SM-3 1A, SM-3 1B, and SM-3 2A. Each block has improved range and capabilities from the previous block.
SM-3 missile block I & II variants
After U.S. withdrawal from Anti-Ballistic Missile Treaty in 2002, Aegis has achieved 35 successful intercepts with 7 failures.
While Aegis has been successful in intercepting ballistic missiles during tests, it has not been used to take out one in real combat.
All the three missile defenses are connected by US military’s C2BMC known as Command and Control, Battle Management and Communications system. So if THAAD fails to make an intercept, the THAAD Radar data could be transmitted to PAC-3 batteries via the C2BMC system and PAC-3 would launch interceptors before the target enters PAC-3 Radar coverage. This means the PAC-3 have the capacity to protect a larger swath of territory due to Interoperation of Missile defenses (via C2BMC).
Missile Defenses integrated by C2BMC
From above image, PAC-3 used against SRBM, THAAD for Short & Medium-range ballistic missiles, SM-3 IA for short and Medium, SM-3 IB for Medium & Intermediate Range, SM-3 IIA for IRBM and some level of plausible defense against small volume ICBM attacks in future.
North Korea has around 1000 ballistic missiles:
1) 500+ Hwasong-5 and Hwasong-6 missiles with a range of 300-500 km
2) 200+ Nodong systems with a range of 1,000 km.
3)100 KN-02 (Soviet-era SS-21 Tochka) missiles with a maximum range of between 90 and 120 km.
So if North Korea fires a barrage or salvo or dozens of such short-range missiles, that would definitely saturate the missile defenses because THAAD, Aegis and Patriot were tested against a limited number of missiles. Even a single missile that missed or evaded missile defenses which may carry chemical or nuclear payload would cause catastrophic damage.
Forget about nuclear missiles, 15,000 artillery pieces pointed towards Seoul could kill tens of thousands in a single volley.
Likely location of hardened artillery sites
North Korea has stashed 15,000 artillery pieces hiding in the hills and mountains behind the military demilitarization line which separates South and North Korea. These artillery guns are protected behind blast doors. A single volley from the North Korean artillery, the report said, “could deliver more than 350 metric tons of explosives across the South Korean capital, roughly the same amount of ordnance dropped by 11 B-52 bombers.”
The distance from Seoul to North Korea is just 56km, so within a matter of minutes, they could strike the South Korean capital. The only practical way to reduce this artillery would be with either a sudden, massive, pre-emptive strike (B-2 Bombers) against the emplacements or using a series of tactical nukes.
But still, U.S. air attacks can’t quickly or easily destroy North Korean guns.
About Krishna Santos KK
Krishna is a B.Tech graduate in Electrical Engineering and PGDC in Thermal power (operation and maintenance) under Ministry of power.