Short- and medium-range ballistic missiles and rockets continue to proliferate. New cruise and supersonic missiles are being developed, and hypersonic missiles may be only a few years away. Stealth aircraft can now be found on three continents. There’s no doubt that medium- and long-range air defense systems are more important than ever, and plenty of them are being touted at the Paris Air Show. But how effective can they be, and at what cost?
There are plenty of assertions made for ground-based air defense systems. Most of these systems are mobile and dual-purpose, designed to intercept aircraft and cruise missiles at all altitudes, as well as tactical ballistic missiles. Some are point-defense systems, some claim area coverage. Either are often part of an integrated system that can be alerted by early warning radars.
Early warning radars can detect aircraft and cruise missiles with radar cross sections (RCS) as low as one-meter square at a range of 300 miles. But if U.S. Air Force claims for the RCS of the B-2 bomber can be believed, that range reduces to 30 miles. However, the development of wideband ground radars does mean that penetrating aircraft must have "broadband stealth."
Ballistic missiles travel faster than stealth aircraft and on more varied trajectories. As one American nonproliferation expert has said, defending against them “is a stunningly ambitious and complex undertaking, unforgiving of the smallest problems.”
The U.S. Ground-Based Midcourse Defense (GMD) against ballistic missiles has absorbed more than $100 billion on interceptor missiles deployed in Alaska. But there have always been questions about its likely success rate, particularly against decoy-dispensing ballistic missiles. Despite this, the Pentagon is upgrading and expanding GMD, driven by the threat from North Korea. It says that a “next generation kinetic kill vehicle” will improve effectiveness against decoys and countermeasures. Boeing is the prime contractor.
The U.S. has seven batteries of the Lockheed Martin Terminal High-Altitude Air Defense System (THAAD), including one deployed on Guam and another in Korea.
The hit-to-kill missiles are guided by Raytheon AN/TPY-2 radars. Each battery is reported to cost $800 million. But according to a former Pentagon advisor, THAAD cannot defend against short- or intermediate-range ballistic missiles (IRBMs) launched on a low trajectory so that they do not enter space.
In a forward-basing mode, the TPY-2 radar also forms a key part in phase 2 of NATO’s European Phased Adaptive Approach (EPAA) that has been prompted by perceived ballistic missile threats from the East. The interceptors are Raytheon SM-3 missiles more usually found on U.S. Navy warships as part of the Aegis system. One site in Romania is operational, with another one in Poland under construction. Raytheon says that forward-basing provides detection of missiles in the launch phase, and that “all of Europe will be protected” once the Polish site is ready. (The initial phase one of the EPAA integrates 10 land- and ship-based radar types operated by seven countries with five types of missile, also operated by seven countries).
Critics say the SM-3 is “too small to reach IRBMs,” but Raytheon insists that it has exo-atmospheric capability, and the latest Block IIA version has a larger rocket motor. Raytheon also makes the SM-6, which additionally offers anti-aircraft and anti-cruise missile capability for warships. Raytheon describes the SM-6 as a successor to the SM-2, but the company reopened the SM-2 production line last year after it was ordered by four countries.
Raytheon’s latest ground radar is the TPY-6, which, it says, can "see" three times farther. This is largely thanks to the much greater power made possible by gallium nitride (GaN) technology, which has replaced the silicon carbide and gallium arsenide used in the first generation of AESA radars. The TPY-6 will be fitted to new Arleigh Burke destroyers, but because it is also modular, the U.S. Navy is considering replacing earlier radars on many of its warships.
Meanwhile, Raytheon is developing the Three Dimensional Expeditionary Long-Range Radar (3DELRR) for the U.S. Air Force, to replace aging TPS-75 systems.
Skepticism about Performance Claims
Part of the skepticism about missile defense systems is driven by exaggerated or misleading interception claims that were made for the Patriot system during the Gulf Wars. The controversy continues today, over supposed intercepts by Saudi Arabia of Scud-type missiles launched by the Houthi rebels from Yemen.
But the Raytheon Patriot is the most widely deployed Western system, sold to 16 countries over a near 40-year existence. The current Patriot Advanced Capability 3 (PAC-3) offering can include a new radar employing GaN technology as well as a choice of missiles. These are Raytheon’s own Guided Enhanced Missile (GEM-T) from the PAC-2 system, and Lockheed Martin’s more recent PAC-3 MSE (Missile Segment Enhancement) hit-to-kill round. Existing customers may need to upgrade to PAC-3: announcing a 2015 sale of PAC-3 to Saudi Arabia, the Pentagon said that earlier Patriot missiles are “becoming obsolete and difficult to sustain due to age and limited availability of repair parts.”
Europe’s equivalent to the Patriot system is awkwardly known by its French acronym SAMP/T (Sol-Air Moyenne Portée/Terrestre). It is produced by Eurosam, a joint venture between MBDA France and Italy, and Thales. It combines Thales radars with MBDA Aster 30 missiles, although the system can be adapted to work with a variety of long-range radars. Poland and Sweden both evaluated SAMP/T but chose Patriot instead.
However, solely as a radar provider, Thales has had great export success with its Ground Master series. The transatlantic joint venture ThalesRaytheonSystems provides NATO’s networked air defense command and control system. Europe’s other major radar house is Hensoldt, offering the new TRML-4D sensor and shorter-range systems, plus a passive radar that can theoretically detect stealth aircraft.
The vertically launched Aster missile was first deployed on French, Italian, and British warships. On the latter, it is paired with Artisan or Sampson radars made by BAE Systems. The Aster has been sold to six other navies. MBDA claims that the latest Aster 30 Block 1 NT (New Technology) version can defend a wide area against ballistic missiles.
Israel has been a pioneer in ballistic missile defense systems, albeit with U.S. money and assistance. The Arrow was co-developed by Boeing and Israel Aerospace Industries (IAI) and is in the same class as the Patriot PAC-3. The Arrow 3 version has exo-atmospheric capability. To defend against short-range ballistic missiles, long-range rockets, and cruise missiles, Rafael co-developed David’s Sling with Raytheon.
The first Israeli missile system to be developed without U.S. assistance is the Barak-8, a co-operation with India that started in 2009. Known there as the Medium-Range Surface-to-Air Missile (MRSAM) system, it is fitted to three destroyers. IAI is the prime contractor, but Rafael is also involved in Israel’s largest-ever defense export contract, worth $1.6 billion. The network-centric architecture allows targets to be updated during the missile’s flight from multiple sources. In the latest test, the system’s Cooperative Engagement operating mode involving multiple platforms and several simultaneous targets was demonstrated.
IAI’s radar subsidiary Elta developed Green Pine for the Arrow and radars for aerostats operated by India and Singapore. Extending the radar horizon with lighter-than-air platforms is theoretically attractive, but has a mixed history. Lockheed Martin provided systems to Kuwait and the UAE, and for U.S. southern border surveillance. But Raytheon’s Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System (JLENS) was a failure.
Not here in Paris due to sanctions, but bound to be a topic of discussion, is the Russian Almaz-Antey design house. It has produced a series of SAMs, starting with the S-300 which entered service in 1979 and was much upgraded before production ended in 2011. It was sold to 17 countries. Then came the S-400 in 2007, a multi-missile system first exported to China in 2015. There was interest from India and Saudi Arabia, and the controversial sale to Turkey. Now the S-500 is being developed, with new radars and missiles. It is in the same class as THAAD but superior, according to its designer. These SAMs have long range, high speed, maneuverability to very high altitude, and resistance to stand-off jamming. However, they do still have separate surveillance and engagement radars, requiring a hand-off that some single-sensor Western systems don’t need.
From the same design house comes the Buk M3, the latest in a series of medium-range SAM systems. One of these shot down Malaysian Airlines MH17 flight over Ukraine. It offers passive tracking by laser or optics, as well as radar. It has been sold to 16 countries.
China has been making great anti-stealth claims for three new long-range air defense radars. They don’t seem credible. But a Rand study in 2016 said that China’s air defense capabilities “are already significant and improving." It calculated that China’s air defense and anti-access (A2AD) capability was already better than Russia’s.
One obvious but little-publicized counter to air defense systems is cyber. This can mean "traditional" offensive electronic warfare against a missile battery, as well as the spoofing of radars by, for instance, inserting false targets. But a cyber attack on an air defense network, for example, its communications, could be far more effective.
What about directed energy? The Pentagon spent more than $5 billion between 1996 and 2012 on the Airborne Laser (ABL) program, to no avail. The world’s first multi-megawatt chemical laser, designed to shoot down intercontinental ballistic missiles in the ascent boost phase, was mounted on a Boeing 747. Lockheed Martin and Northrop Grumman were subcontractors to Boeing, which was the system integrator. However, technical lessons were learned from ABL, especially in beam propagation and control.
The Pentagon switched focus. It is funding development of smaller, solid-state lasers that could be carried by high altitude unmanned platforms—if enough electric power can be provided. It has also been exploring infrared or laser missiles carried by medium-altitude MQ-9 Reaper drones, patrolling close enough to threat countries to make interceptions in the boost phase, after tip-off from the Space-Based Infrared Satellite (SBIRS) system.
The U.S. has also funded development of Electro Magnetic Rail Guns (EMRGs) that could protect ships against cruise and ballistic missiles. But the project has foundered for various reasons. France and Germany have also funded research, and a large EMRG has been seen on a Chinese warship.
At the tactical level, Boeing demonstrated 10 years ago that a trailer-mounted solid-state laser could shoot down UAVs. Since then, terrorists have added explosives to small, commercially available drones, and used them. Palestinian militants have also used $500 short-range rockets, against which Israel has deployed Iron Dome. This can also shoot down low-flying aircraft, but just how effective it would be against a massed launch of Qassam rockets is unknown. Intercepting such threats by lasers would provide a far better cost-benefit ratio.
The 2015 Patriot sale to Saudi Arabia was valued at no less than $5.6 billion, to include 600 missiles. Even if one allocates two-thirds of this value to account for the ancillary equipment and services, that makes the cost of each missile $2.75 million. No wonder that the Rand study estimated that even a basic short-range ballistic missile costs nine times less than the three Patriot rounds needed to defeat it.