The topic of ballistic missile defence, regardless of geographic region, is rife with complexities, and two major areas stand out – the geopolitical aspect and the technological aspect.
From a geopolitical perspective, one can clearly understand that if a shooting conflict arises, it can often be traced to a failure in diplomacy. Politicians often use military capability as a lever in diplomacy, and that usually turns into a competition of move and counter-move between opponents, with each party spending enormous amounts of resources in the process.
It is no secret that aligned nations in the Asia-Pacific region are expending considerable investment in research and development and weapon systems acquisition to counter the growing ballistic missile threat posed by state actors like Russia and China, the later of which is developing the DF-21 and DF-26 missiles which offer improved range, accuracy, lethality, and reliability over legacy Chinese systems.
Speaking to the threat posed by China’s missile forces was U.S. Navy Admiral Philip Davidson, the Expected Nominee for Commander U.S. Pacific Command, who responded to Advance Policy Questions by saying: “The threat to U.S. forces and bases is substantial and growing. The People’s Liberation Army Rocket Forces have a growing inventory of medium- and intermediate-range ballistic missiles than can threaten U.S. bases in the region, including those in South Korea, Japan, and Guam, as well as naval forces operating inside the Second Island Chain. Many are purpose-built for specific targets, such as aircraft carriers or air bases, and PLA Rocket Forces maintain a high degree of combat readiness. Moreover, China is constantly evolving its missile technology, increasing their range, survivability, accuracy, and lethality.”
Of particular concern in the Asia-Pacific are the destabilizing actions of North Korea through its numerous launches of ballistic missiles in recent months. These actions have focused allied nations in the region to accelerate deployment of ballistic missile defences. Naturally, the United States leads the way in this capability and is a key partner with Japan and South Korea.
Speaking to U.S. force posture in the PACOM area of responsibility which could improve deterrence against North Korea, Admiral Davidson wrote: “I believe we have the capability today to deter North Korean aggression, but given where we think the North Korean capability might be in terms of their missiles in the next five years, I think we must continue to explore, improve, and resource our entire missile defense capabilities… I support planned improvements to the BMD of the Homeland architecture via the new Homeland Defense Radar for Hawaii, additional purchase of Ground Based Interceptors, and a detailed study that ascertains the efficacy of positioning interceptors in Hawaii. Lastly, I support continued improvements in the capability and capacity of ballistic/cruise missile defense interceptors that will further enhance homeland defense capabilities and protect key regional nodes from North Korea’s aggressive action against the United States.”
Technological challenges to ballistic missile defence
To understand ballistic missile defence, one must first understand the key phases of flight that these missiles take. Upon launch, a ballistic missile begins its boost/ascent phase which lasts approximately 3 – 5 minutes, this is followed by a mid-course phase to apogee, and finally a re-entry/ terminal descent phase.
One may think that the boost/ascent phase is the easiest to intercept, however there are various reasons why this phase is particularly challenging. First, a launch must be detected within seconds to formulate a response. Second, the course of the ballistic missile must be determined to ascertain if it is a legitimate threat, and this is best known upon approaching apogee. Third, an interceptor must be close enough to react, however the ramifications of launching a weapon into a sovereign country to intercept a ballistic missile in the boost phase, even if that country is a foe, is fraught with potentially perilous consequences. It is for these reasons that ballistic missile defence is primarily focused at the mid-course and terminal phases of flight.
It should be noted that the United States has explored intercepting ballistic missiles in the ascent phase, notably with the Boeing YAL-1 Airborne Laser Testbed weapons system, which was a modified Boeing 747-400F fitted with a chemical oxygen iodine laser. After years of testing, the YAL-1 system continued to face a number of operational and technical challenges, let alone being extremely expensive, which resulted in its funding being cut in 2010.
The idea of a persistent airborne laser which can intercept ballistic missiles in the boost phase has not been put to rest however, as the United States is examining ways to mount newer types of lasers on unmanned aerial vehicles; but fielding of such a system, if viable at all, is still years away.
Speaking to Asian Military Review for this feature was Dr. Bill Wieninger, a Professor of Security Studies at the Daniel K. Inouye Asia-Pacific Center for Security Studies in Hawaii, and a former lecturer at the Defense Nuclear Weapons School in Albuquerque, New Mexico. “After spending an awful amount of money, we’ve gotten somewhat effective at shooting down shorter range missiles, but we cannot have confidence in shooting down long range intercontinental ballistic missiles. The big distinguisher seems to be how fast the missile is going – ICBMs go at approximately 7 kilometers a second, so that’s an amazingly difficult technical challenge which I’m not sure we’ll ever be able to master,” said Dr. Wieninger. “A further challenge are decoys which are relatively easy to field and dramatically complicate the targeting challenge. From a technological perspective we may be able to intercept some, perhaps 70%, but from a geopolitical perspective, let alone a humanitarian perspective, even just one nuclear tipped missile getting through would clearly be devastating. Moreover, misplaced confidence in BMD may lead to unacceptably dangerous crises.”
The United States Department of Defense (DoD) FY19 budget highlights the importance of missile defence programs and calls for investments that will “focus on layered missile defenses and disruptive capabilities for both theater missile threats and North Korean ballistic missile threats.” Those investments for FY 2019 include: 43 AEGIS Ballistic Missile Defense (SM-3) – $1.7 billion; Ground Based Midcourse Defense – $2.1 billion; 82 THAAD Ballistic Missile Defense – $1.1 billion; 240 Patriot Advanced Capability (PAC-3) Missile Segment Enhancements – $1.1 billion. The budget also supports U.S. Forces Korea to improve missile defence capability on the Korean peninsula.
A layered approach to ballistic missile defence
There are a number of effectors which are brought to bear against the ballistic missile threat. The first part of the kill chain is missile launch detection and tracking. One of the key systems focused on this is the Space-Based Infrared System (SBIRS) which uses infrared surveillance to provide early missile warning for the U.S. military. The system includes a combination of satellites and hosted payloads in Geosynchronous Earth Orbit (GEO) and Highly Elliptical Orbit (HEO), and ground hardware and software. The recent U.S. DoD FY19 budget funds the Air Force’s Next-Generation Strategic Missile Warning system as part of a transition to the future Overhead Persistent Infrared (OPIR) satellite architecture. This Next-Generation system will increase strategic survivability and will incorporate a technology refresh of the sensor to assure missile warning capabilities equal to or greater than today’s SBIRS.
In addition to SBIRS, the United States operates a number of other radar systems in the Asia-Pacific region, each engaged in the ballistic missile defence effort. One of these systems is the Sea-based X-band radar (SBX-1), which is part of the Missile Defense Agency’s Ground Based Midcourse Defense (GMD) system which links to Ground-Based Interceptor (GBI) missiles based at Fort Greely, Alaska, and at Vandenberg AFB in California.
Another key component of ballistic missile defence in the Asia-Pacific is the Aegis Ballistic Missile Defense (BMD) system. Aegis BMD builds upon the existing Aegis Weapon System and is designed to detect and track ballistic missiles of various ranges in all phases of flight with the ability to destroy short through intermediate-range ballistic missiles in the midcourse and terminal phases for flight with the Standard Missile-3 (SM-3) and Standard Missile-6 (SM-6) missiles. Ships in the U.S. Navy and Japanese Maritime Self-Defense Force are configured with Aegis BMD, and are on routine patrol throughout the Asia-Pacific. In late 2017, Japan decided to acquire two Aegis Ashore BMD systems.
Upgrades are being made to the Aegis BMD weapon system and FY19 begins a 5-year multiyear procurement contract for the SM-3 Block IB missile, with 37 being procured in the first year. The budget also supports procurement of six SM-3 Block IIA missiles; integrates SM-3 Block IIA into the BMD Weapon Systems; and continues development of the Aegis BMD 5.1 and Aegis BMD 6 Weapon Systems.
Another radar system, the Army/Navy Transportable Radar Surveillance-2 (AN/TPY-2) is an X-band missile defence radar built by Raytheon Integrated Defense Systems. Depending on the needs of the warfighter, the AN/TPY-2 radar can be deployed in two different modes. In forward-based mode, the radar is positioned near hostile territory, and acquires ballistic missiles in the boost phase of flight. It then tracks and discriminates the threat, and passes critical information required by decision makers to the Command and Control Battle Management network. When the AN/TPY-2 radar is deployed in terminal mode, the radar’s job is to detect, acquire, track and discriminate ballistic missiles in the terminal (descent) phase of flight.
The AN/TPY-2 radar links to Lockheed Martin’s Terminal High Altitude Area Defense (THAAD) system. THAAD missiles are able to engage a wide class of short and medium-range ballistic missiles in both the endo-and exo-atmosphere using hit-to-kill technology. THAAD is in operation on the U.S. territory of Guam; and a single THAAD battery has recently been deployed to South Korea and is operation today. A THAAD Battery consists of 6 truck-mounted launchers, 48 interceptors (8 per launcher), one AN/TPY-2, and one Tactical Fire Control/Communications component.
Rounding out the major ballistic missile defence systems present in the Asia-Pacific region is the Patriot, a high to medium altitude, long-range air defense missile system. The Patriot system has a number of variants and types of missiles which offer blast fragmentation warheads, or kinetic hit-to-kill capacity. Patriot Systems are fielded in the Asia-Pacific by the United States, Japan, Taiwan, and South Korea.
The Patriot Advanced Capability 2 (PAC-2) launches MIM-104C missiles, some of which have been modified to Guidance Enhanced Missiles (GEM) which are built by Raytheon Integrated Defense Systems.
William G. Patterson, Senior Director IAMD programs, Raytheon Integrated Defense Systems said: “We are now looking at helping some of our partners in upgrading and re-certifying the Patriot Guidance Enhanced Missiles that are nearing the end of their service life. The GEM missile has a blast-fragmentation warhead and has proved incredibly effective in combat. Since Jan of 2015, Patriot has intercepted more than 100 tactical ballistic missiles in combat operation, and more than 90 of those engagements were with the GEM.” Patterson added, “What we’ve learned from recent combat operations is that not all threats require hit-to-kill interception. In some cases, the blast-frag warhead is actually more effective at engaging threats. So we are proposing to rectify GEM, upgrade it, and keep it in the inventory of certain customers. Doing this will only cost a fraction of the cost of purchasing new Patriot hit-to-kill missiles, and give them the capability they need.”
Lockheed Martin Missiles and Fire Control builds the PAC-3 Missile Segment upgrade to the Patriot air defense system. The PAC-3 Missile Segment upgrade consists of the PAC-3 Missile (MIM-104F), PAC-3 Missile canisters (in four packs), a fire solution computer and an Enhanced Launcher Electronics System.
The ‘Hit-To-Kill’ PAC-3 Missile is a high velocity interceptor that defeats incoming targets by direct, body-to-body impact. PAC-3 Missiles, when deployed in a Patriot battery, significantly increase the Patriot system’s firepower since 16 PAC-3s load-out on a Patriot launcher, compared with four Patriot PAC-2 missiles. According to the U.S. DoD, joint efforts between the U.S. Army and the Missile Defense Agency have been successful in integrating PAC-3 capabilities into the Ballistic Missile Defense System (BMDS).
Lockheed Martin has further enhanced PAC-3 capability with the PAC-3 Missile Segment Enhancement (MSE), an evolution of the PAC-3 Missile. The PAC-3 MSE incorporates a larger, dual pulse solid rocket motor; larger fins; and upgraded actuators and thermal batteries to accommodate increased performance – these modifications extends the missile’s range and flexibility.
Speaking to Asian Military Review for this article was Howard Bromberg, Vice President for Strategy and Business Development, Integrated Air and Missile Defense for Lockheed Martin Corporation, who spoke to the company’s BMD strategy: “THAAD is part of our hit-to-kill family of missiles which are able to engage both inside the atmosphere and outside the atmosphere. The Aegis Ashore system and the Aegis BMD ships use the Standard 3 missile, and they only engage outside the atmosphere. Then you have the PAC-3 missile that engages inside the atmosphere down below where THAAD engages. We’re in full production with PAC-3 MSE; it’s fielded with the U.S. military and we’re starting to field it to international customers. You can see that what we’ve done with our family of missiles is create a layered defence with hit-to-kill missiles which ensure warhead destruction. That’s extremely important because no one knows what’s going to be in those warheads. All of these elements are in the Asia-Pacific region.”