The recent National Academy of Sciences (NAS) Report Making Sense of Ballistic Missile Defense indicates that in addition to deploying Aegis Ashore sites in Romania and Poland, the Missile Defense Agency would like to deploy a TPY-2 X-band radar at each site. Specifically the report states (in its appendix on System Cost Methodology) that: “As part of the Phased Adaptive Approach for the European missile defense system, MDA has proposed that each interceptor site location include a forward-based (FBM) AN/TPY-2 X-band radar system.” If true, this statement has several interesting possible implications about the MDA’s radar plans.
A TPY-2 radar undergoing environment testing. (Picture source: Missile Defense Agency)
First, it would seem to provide further support for the idea, most clearly spelled out in the telephone press conference announcing the NAS Report’s release, that the Aegis radars really play a secondary role in the EPAA. As discussed in the post of September 13, 2012, in the NAS view of the European Phased Adaptive Approach, the Aegis radars primarily serve as communication relays to the interceptors, transmitting the target track data from the more powerful X-band radars.
Alternatively, it could reflect plans to co-locate a Terminal High Altitude Area Defense (THAAD battery with each Aegis Ashore site, since a TPY-2 radar can be used as either a Forward-Based X-band (FBX) radar or a THAAD Battery radar. However, it is hardtop see why this would be needed, unless doubts existed about the ability of the Aegis Ashore site to defend itself from ballistic missile attack.
Secondly, if true, this statement would indicate that the supply of available TPY-2s is beginning to dwindle. The U.S. currently plans to plans to buy 11 TPY-2 X-band radars, with the last of these scheduled to be delivered in fiscal year 2015. Three of these are already deployed as FBXs in northern Japan, Israel, and Turkey.
In July, The Wall Street Journal reported that a fourth TPY-2 was being deployed to Qatar (see post of July 18, 2012). In August, the same newspaper reported that the U.S. planned to deploy a TPY-2 in the near future to a southern Japanese island (not Okinawa) and was also evaluating potential sites, such as in the Philippines, for a third X-band deployment to eastern Asia. (The NAS study assumes a TPY-2 radar in southern Japan (although not on an island), so this deployment may have been in the works for some time — or maybe it’s just an obvious place to put a radar).
If TPY-2s are also deployed to the Aegis Ashore Sites in Romania and Poland, and one or two radars are reserved for testing and overhaul, this would account for 9 to 10 of the planned 11 TPY-2 radars. Then where do the radars for the 6 currently planned THAAD batteries come from?
One possibility is that more TPY-2 radars might be procured. However, the number of planned radars was just cut from 14 to 11 in the Pentagon’s budget announced in February 2012 (coincident with the number of planned THAAD batteries being cut from 9 to 6), and the MDA budget summary table released at that time shows zero TPY-2s being bought from FY 2014 to FY 2017 (which is as far out as the summary table goes).
Alternatively, THAAD batteries could be deployed alongside one or more of the forward-deployed X-bands. So far two THAAD batteries have been delivered, with one each planned for delivery in FY2013 through 2016. The two batteries delivered so far are still apparently in the U.S., although the July Wall Street Journal article indicated that one of them might be deployed to Qatar in the near future. And of course, the radars can be quickly moved by air transport and converted from a forward-based to a THAAD mode very quickly. Still, there don’t seem to be quiet enough radars to go around.
 National Academy of Sciences Report, p. E-61, note c.
 Adan Entous and Julian E. Barnes, “U.S. Plans New Asia Missile Defense,” The Wall Street Journal, August 23, 2012, p. A1.