Raytheon Corp on March 5th reached a new milestone by successfully testing a Standard Missile-3 (SM-3) ballistic missile interceptor using a non-Aegis data link, an important step in efforts to equip more naval vessels to employ the full range of missiles in the Standard Missile family.
The SM-3 Block IA interceptor uses an S-band data link that can “handshake” with the AN/SPY-1 used on Aegis-equipped warships to provide guidance toward medium-range airborne targets in the exo-atmosphere. The SM-3 Block IB, currently under development and expected to enter service in 2015, also uses the S-band as a data link baseline.
However, aware of the limitations that reliance on S-band-compatible data links posed for SM-3 sales and regional cooperation in “upper tier” air defense, in 2010, Raytheon began developing a prototype dual-band data link that would enable warships to use both the S-band and X-band radar to communicate with SM-3 missiles.
For the time being, those efforts appear to be focused on European navies. A little more than a week after the March 5th test — jointly funded by Raytheon Corp and Thales Nederland — at Fort Erfprins in the Netherlands, reports emerged that Raytheon was discussing plans for a possible pooling of SM-3 missiles with the Dutch, German and Danish navies.
Although none of the three European navies appear to have immediately committed to purchasing SM-3 missiles, the Dutch navy has expressed initial interest in upgrading the Signaal Multibeam Acquisition Radar for Tracking-L and Advanced Phased Array Radar (SMART-L/APAR) sensor suites and other systems on its warships so they can provide targeting data to SM-3 missiles deployed by other navies in the region (the APAR uses the X band). At present, seven warships in the Dutch and German navies are equipped with SMART-L/APAR X-band radars, with three in the Danish navy.
A SM-3 datalink that operates on both the S-band and X-band would also remove the need for the U.S. Navy (and potentially allied navies) to hold inventories of Standard Missiles for both the Zumwalt (X-band) and Aegis (S-band) classes of ships.
While talks of possible SM-3 pooling and data sharing in Europe continue, the U.S. Navy is also focusing on the Asia-Pacific region for cooperation with allies on missile defense. With the threat of ballistic missiles in East Asia constantly growing, the Pentagon announced in August 2012 that it would deploy a second X-band radar in Japan, with reports at the time alleging that the U.S. was mulling plans to deploy a third system somewhere else in the region like the Philippines to create an “arc” across East Asia to bolster missile defenses against North Korea.
Although efforts were made to avoid giving the impression that such plans did not target China, the program also holds great potential as a means to counter China’s growing missile threat against a variety of targets within the region, including air bases in Okinawa, critical infrastructure in Taiwan, and U.S. carrier battle groups at sea.
Sea-based medium- and long-range (Block IIB) air defense provided by SM-3 serve as a complement to existing ground-based systems, such as the PAC-3, and have the added advantage of mobility. In East Asia, this added layer currently revolves around Aegis-equipped destroyers from the U.S. 7th Fleet and the Japanese Navy, which has Aegis destroyers armed with SM-3 IA interceptors (Japan and the U.S. are also co-developing the SM-3 IIA). Of the other major navies in the region, the South Korean and Taiwanese navies also field a variety of SM-1 and SM-2 missiles.
Much as in Europe, navies within the region with modern enough fleets could, assuming proper capital injections and political will, eventually be equipped with SM-3s. This is certainly feasible for Taiwan, South Korea and, in the larger Indo-Pacific region, Australia, Singapore and India. A SM-3 pooling system, much like the one currently being considered in Europe, is also a possible scenario in Asia, though for the moment there is no indication that such plans have been discussed, an industry source told The Diplomat.
Even if regional navies are unwilling or unable to accommodate SM-3 technology on their warships, the development of dual S-band/X-band data links and the ability to adapt those for use on existing platforms could lead to the deployment, at some point in the future, of a sea alliance of regional navies providing mobile, flexible, and redundant tracking for SM-3s deployed by the U.S. and Japanese navy vessels.
Given the complex challenges posed by North Korea and China’s ballistic missiles, added to the vastness of the territory requiring missile intercepts in the Asia-Pacific, such flexibility would be a sensible addition to fledging U.S. efforts to increase security for its regional allies.