EKVs, RKVs, CKVs, MOKVs and More. (April 26, 2014)

There have been at least as many acronyms and designations assigned to current, past and future kill vehicles of the Ground-based Midcourse Defense (GMD) national missile defense system as there have been successful intercept tests of such kill vehicles.  Below I summarize the most important of these kill vehicle designations.

EKV CE-0: This designation covers the kill vehicles used in the first seven GMD intercept tests, from 1999 to 2002, as well as the IFT-1a and IFT-2 fly-by tests in 1998-99.  The first, and so far only, place I have seen this designation is on the slides used by MDA Director Admiral Syring during his August 13 presentation at the 2014 Space and Missile Defense Conference.  (These slides were obtained via FOIA by Laura Grego of the Union of Concerned Scientists.)  These kill vehicles are sometimes referred to as “prototypes” although this term is sometimes also used for the later CE-I and CE-II kill vehicles as well.  The “CE” stands for Capability Enhancement, so the CE-0 designation seems to be both a retroactive designation as well as a catch-all for all the early GMD kill vehicles, as indicated by its use for both the fly-by tests, which used two completely different competing kill vehicle designs.

EKV CE-0+:  This designation was also used by Admiral Syring in his SMDC presentation.  It is not clear (at least to me) how this version of the kill vehicle differed from its CE-0 predecessor.  In any event, this version of the EKV has never left Earth’s atmosphere.  It was only used in two intercept tests (IFT-13c in 2004 and IFT-14 in 2005) and in both of these tests the interceptor failed to launch.

EKV CE-1:   The Capability Enhancement – 1 (CE-I) was the initial production version of the EKV.  CE-I EKVs were first delivered and deployed in 2004, and deliveries and deployments continued until September 2007.  The number of deployed CE-1 GBIs peaked at twenty four in September 2007, although some of these deployed CE-Is have since been replaced by newer CE-II equipped GBIs.  A total of 33 CE-I equipped GBIs were produced, with six of these expended in flight or intercept tests so far.  The CE-I differs from the last CE-0s in at least some connector upgrades that were made to address obsolescence problems.  Other changes were made to the CE-I EKV as problems with it were identified through testing.  A 2014 DoD Inspector General Report notes that there are “subconfigurations” within the basic CE-I design as a result of these changes.

The CE-I has been flight tested six times, with four of these being intercept tests. The MDA classifies the first three intercept tests, conducted in 2006-2008, as successful intercepts, although in the first only “a glancing blow” was struck to the target.  The fourth intercept test, FTG-7 in July 2014, was in part intended to demonstrate roughly twenty five upgrades made to the CE-I EKV.  However, the intercept attempt failed due to a problem with a battery.  The FY 2013 Annual Report by the Director of Operational Test and Evaluation recommended that MDA “Conduct a redo of the FTG-07 test with a GBI equipped with a CE-I EKV…”  However, no such retest has occurred so far.  The next scheduled intercept test for a CE-I-equipped GBI appears to be as part of FTG-11 in 2017, a salvo test involving both CE-I and a CE-II GBIs.

EKV CE-II:  Facing obsolescence issues with some components of the CE-I, in 2005 MDA began design of a new Capability Enhancement-2 (CE-II) version of the EKV.  Deployment of CE-II-equipped GBIs began in October 2008.  A total of ten were deployed before the failure of December 2010 FTG-06a intercept test led to a halt in their deployment.  MDA has procured a total of twenty four CE-II equipped GBIs.  Sixteen of these had been delivered by September 2014; the remaining eight are to be delivered in 2015.

Although the CE-II program was initiated primarily to address obsolescence issues (in particular in its computer processor), it also provided some improved kill vehicle capabilities (see my post of April 3, 2012).  Relative to the CE-I, the CE-II has a more sensitive infrared seeker, and the new processor is said to provide improved onboard discrimination capabilities.  Specifically, the CE-II upgrade increased the number of objects the kill vehicle could track, and had some “minor” algorithm performance improvements.[1] As with the CE-I, there are subconfigurations within the basic CE-II design.

The CE-II EKV has been flight-tested four times, three of which involved intercept attempts.  The first two intercept flight tests, FTG-06 and FTG-06a, both failed in 2010.  A successful non-intercept flight test (CTV-01) in January 2013 and a successful intercept test in June 2014 permitted deployment of CE-IIs to begin again.

EKV CE-II Block 1: The CE-II Block I is an improved version of the CE-II EKV.  It will at least incorporate new components to address the guidance failure in FTG-06a and the battery-related failure in FTG-07.  No other improvements have been publicly disclosed, but the Block 1 is intended to have increased reliability relative to the previous CE-II EKVs.

The first flight test of the Block 1 is currently planned to be the FTG-15 intercept test in late 2016. This will also be the first test of an operationally-configured GBI against an ICBM-range target.  If this test is successful, ten CE-II Block 1 interceptors will be delivered and deployed in 2017, bringing the total number of deployed to the MDA’s goal of 44.

RKV:  The Redesigned Kill Vehicle (RKV) is new kill vehicle that will incorporate largely existing kill vehicle components and subassemblies into a new modular design. It has also been referred to as the “EKV CE-III.”[2] According to MDA Director Admiral Syring: “The new EKV will improve reliability and be more producible, testable, reliable and cost effective and eventually will replace the kill vehicle on our current GBI.”[3]  In addition, the RKV will also have improved target acquisition and discrimination capabilities and provide for on-demand communications between the RKV and the GMD fire control system.  MDA requested $229 million for RKV development in FY 2016, with total development spending planned as $658 million through FY 2020.

MDA plans to design the RKV itself using the best elements of proposals from Raytheon, Boeing and Lockheed-Martin, with a production award contest in 2018.  Under current plans the RKV will have a first flight test in 2018 followed by an intercept test in 2019.  If these tests are successful, deployment of the RKV on Ground-Based Interceptors (GBIs) would begin in 2020, likely replacing already deployed EKV-equipped GBIs.

CKV: There is no kill vehicle known as a Common Kill Vehicle (CKV).  Rather, the Common Kill Vehicle Program is a two-phase effort aimed at developing strategies and technologies for “the next generation of our exo-atmospheric kill vehicles.”[4]  MDA requested $47 million for the CKV program in FY 2016 and plans to spend $380 million on the program through FY 2020.

In the first phase of the CKV Program, begun in 2014, concepts and requirements were developed for the RKV.

The second phase, to begin in FY 2016, will involve both developing concepts for Multi-Object Kill Vehicles (MOKVs – see below)).  It will also involve developing strategies and technologies, such communication architectures, guidance technologies, and command and control strategies that might be used in a future MOKV program.

MKV: The Multiple Kill Vehicle (MKV – sometimes Miniature Kill Vehicle) program was started by MDA in 2004.  Its objective was to produce a kill vehicle small enough that several or many MKVs could be placed on a single interceptor, with each MKV able to intercepting a separate target.  This program aimed to reduce the problem of discrimination by allowing every credible object in a threat cloud to be attacked.  The MDA announced the termination of the MKV program in 2009, saying it would instead “invest in technologies that would defeat threat missiles in their ascent phase before deployment of countermeasures,” an approach that was abandoned several years later.  Prior to abandoning it, MDA spent nearly $700 million on the MKV program.

MOKV: The Multiple-Object Kill Vehicle (MOKV) is a revival of the MKV concept.  Current plans call for work on the MOKV to begin in FY 2016 under the Common Kill Vehicle program with MDA awarding several contracts to industry to develop MOKV concepts.  In parallel, MDA will invest in developing several key MOKV technologies.  According to MDA Director Admiral Syring in 2015 congressional testimony: “Ultimately, these Multi-Object Kill Vehicles will revolutionize our missile defense architecture, substantially reducing the interceptor inventory required to defeat an evolving and more capable threat to the Homeland.”[5]  However, even if the MOKV program is successful, MOKVs may not be deployed until 2030.[6]

[1] Admiral Syring’s 2014 SMDC Conference presentation slides.

[2] Amy Butler, “Reprieve and Refocus,” Aviation Week and Space Technology, September 1, 2014, pp. 21-22.

[3] Statement of Vice Admiral J.D. Syring to the Defense Subcommittee of the Senate Appropriations Committee, June 11, 2014.

[4] Admiral J.D. Syring prepared statement to the Subcommittee on Defense, Senate Appropriations Committee, March 18, 2015.

[5] Syring prepared statement.

[6] Lee Hudson, “MDA Continues Balancing Congress, Budget While Achieving Homeland Defense Initiatives,” Inside Defense SITREP, December 16, 2014.

The Long Range Discrimination Radar at S-Band? (April 20, 2015)

It appears likely that the Ground-Based Midcourse (GMD) Defense’s new Long Range Discrimination Radar (LRDR) will operate at S-band instead of at X-band. This raises the question of whether the better range resolution that would have been available at X-band is being sacrificed in order to keep the initial cost of the LRDR down to about $1 billion. Or is there some other reason?

Although the current Ground-Based Midcourse (GMD) national missile defense system nominally provides coverage of all 50 states from limited intercontinental ballistic missile attack, it is well known that the system is severely lacking in its discrimination capabilities. In particular, the primary sensor infrastructure (aside from the infrared seekers on interceptor kill vehicles) for the GMD system consists of five radars — seven within a few years — in the United States, Greenland and Britain that were originally built for ballistic missile early warning purposes.[1] These radars date to the 1970s-1980s, but have subsequently received (or will soon receive) relatively minor upgrades that allow them to detect and track incoming missiles as part of the GMD system.[2] However, the relatively low operating frequency of these radars (about 440 MHz, corresponding to a wavelength of about 0.68 m) limits their bandwidth, resulting in a minimum range resolution of no less than about 5 meters.[3] This low resolution limits these radars to at best being able to only classify objects as potentially threatening (warheads, decoys, booster stages, etc…) or non-threatening (small pieces of debris).[4]

These large early warning radars are supported by forward-deployed TPY-2 X-band radars (in Japan and Turkey) and by S-Band Aegis radars on U.S. Navy ships, which have superior range resolution capabilities, but have limited range and can only observe a North Korean or Iranian missile in the early part of its trajectory.

The only very large radar in the GMD system capable of making high resolution measurements is the Sea-Based X-Band (SBX) radar. This radar, with a 17.8 m diameter antenna, is capable of tracking missile targets at ranges of thousands of kilometers with a theoretical range resolution as low as 0.15 meters, although in actual practice this is probably more like 0.2-0.25 meters. However, the SBX was built primarily for testing purposes and as such has a number of limitations that severely impair its usefulness as an operational radar in the GMD system. Most importantly, it has a very limited electronic field of view (FOV). The electronic FOV is the range of angles over which the radar beam can be steered almost instantaneously, without having to move the radar antenna. A single radar face of a typical phased array radar, such as the U.S. early warning radars, has an electronic FOV of about 120 degrees, while the electronic FOV for the SBX is only about 25 degrees. The small electronic FOV seriously limits the capability of the SBX to deal with multiple targets that are separated by large angles. In addition, the SBX was not built to have the reliability that would be required of an operational system.   These deficiencies of the SBX are highlighted in a recent Los Angeles Times article.

In March 2014, at its FY 2015 budget release press conference, the MDA announced that was starting a program to design and deploy a new Long-Range Discrimination Radar (LRDR) for the GMD system.[5] Such a deployment was required by the FY 2014 Defense Authorization Bill of December 2013, which stated that: “The Director of the Missile Defense Agency shall deploy a long-range discriminating radar against long-range ballistic missile threats from the Democratic People’s Republic of Korea. Such radar shall be located at a location optimized to support the defense of the homeland of the United States.”[6] The MDA’s announcement was also consistent with repeated statements by the MDA that improving the discrimination capabilities of the GMD system was one of its top priorities. For example, in July 2013 when MDA Director Admiral Syring was asked in a congressional hearing where he would spend his “next dollars” in order to improve the GMD system, he stated that “I would spend our next dollar on discriminating sensors, meaning radars, big radars west and east, to give us the capability of where I see the threat going in the next five to ten years.”[7]

The LRDR is to be deployed in 2020 in Alaska and is expected to cost about one billion dollars. MDA plans to award a contract for the radar by the end of the current fiscal year. The LRDR will most likely be built at Clear Air Force Station in central Alaska (currently home to a PAVE PAWS early warning radar that is in the process of being incorporated into the GMD system) or at Eareckson Air Station on Shemya Island at the western end of the Aleutian island chain (currently home to the large Cobra Dane radar which has already been incorporated into the GMD system). Once the LRDR is operational, the SBX would most likely be moved to an East Coast location — where it would still suffer from the same limitations it has now.

MDA’s initial March 2014 LRDR Request for Information (RFI) to industry stated that it was not specifying the operating frequency band for the radar but rather was “looking for recommendations with rationale” based on tradeoffs necessary for the radar to perform its “precision tracking, discrimination and hit assessment” missions.[8] It also raised the possibility that the radar could have a limited field of view (LFOV) phased-array antenna instead of a full field of view (FFOV) antenna, and that in addition to its electronic-scanning capability, its antenna could be mechanically steered in azimuth or elevation or both (which would be necessary if a LFOV design was chosen — see below for a discussion of FFOV and LFOV radars). It also stated that MDA was interested in “software/hardware reuse and economy-of-scale benefits from existing programs leveraging the current and near-term production base.

An August 2014 update to the LRDR RFI provided additional insight into MDA’s plans for the radar.[9] It asked bidders for the LRDR to provide price estimates for three different LRDR configurations. Significantly, all three of these configurations would have the radar operating in the S-band of radar frequencies (2-4 GHz). One radar configuration would have a single antenna face. Another configuration would have two antenna faces. A third configuration would also have two antenna faces, but only one face would be populated with the modules that transmit and receive the radar energy (T/R modules). The second, inactive face could subsequently be populated with modules if such an upgrade was later determined to be needed. A subsequent RFI update stated that “Both radar faces will be designed to accommodate the same antenna hardware necessary to achieve the same future growth sensitivity.”[10]

At a February 2, 2015 Pentagon press conference on MDA’s FY 2016 budget, Admiral Syring stated that “we’re asking for a two phase capability” for the LRDR.

Phased array radars typically are limited to maximum electronic scan angles of roughly ± 60 degrees because of losses associated with larger scan angles. Phased arrays with maximum scan angles of roughly ±60 degrees are referred to as full field-of-view (FFOV) radars. Such radars have antenna modules spacing of less than about 0.6 λ, where λ is the radar wavelength. For phased-array antennas with larger module spacings, another limitation on the maximum scan angle arises from the need to avoid grating lobes, which are essentially additional main radar beams. Phased array radars with significantly reduced scan angles due to wide module spacings are referred to as limited field of view (LFOV) radars.[11]

For radars which have modules arranged on a square array, such as the SBX, a module spacing of 0.536 λ or less is needed to obtain a ±60 degrees scan angle without producing grating lobes.[12] This corresponds to a maximum allowable antenna area of 0.287λ2 per module. For an antenna with modules arranged on an equilateral triangular array, such as the U.S. early warning radars, this maximum permissible antenna area is 0.332λ2.

For example, a PAVE PAWS early warning radar has 2677 elements arranged in equilateral triangular array with an area of 384 m2. Of these elements, 1792 are actual transmit/receive modules, and the other 685 are dummy elements. The area per element is then 384/2677 = 0.143 m2 = 0.310 λ2 at a wavelength of λ= 0.68 m. This less than the maximum permitted area of 0.332λ2 m2 for a ± 60 degree scan, and thus the PAVE PAWS can achieve a full ±60 degrees scan angle, or even a little more, without producing grating lobes.

On the other hand, the SBX has 45,264 modules on a square array with an area 249 m2.   This corresponds to an area per module of 55.0 cm2 and a spacing between of modules of 7.42 cm = 2.35λ assuming a frequency of 9.5 GHz. For radars with widely spaced elements on a square array, the maximum scan angle θM is approximately given by sinθM = ±(0.5λ/d), where d is the module spacing.[13] With the SBX’s module spacing of d = 2.35λ, the maximum electronic scan angle is ±12.3 degrees. Thus the SBX is definitely a LFOV radar.

To get a FFOV of ±60 degrees on the same size antenna, the SBX would have required about (2.35/0.536)2 = 19.2 times more modules, or a total of 45,264 x 19.2 = 869,000 modules. Not only would this have been prohibitively expensive, but it likely would have significantly delayed the deployment of the SBX by years unless costly new module production lines were opened. In addition, it would also have resulted in a radar with much greater capabilities than could ever be used in a missile defense role, given the curvature of the earth and the maximum altitude of ballistic missile trajectories. Alternatively, the SBX could have designed to use the same 45,264 modules but with a 0.536λ module spacing, resulting in an FFOV antenna, but with a diameter of only about 4.1 m. This would have reduced its tracking range, taken to be proportional to the 4th root of the product of its power x aperture area x gain (P-A-G), by a factor of (1 x 19.2 x 19.2)0.25 = 4.4.

For phased arrays using antennas populated with T/R modules, the modules are generally the biggest cost driver of the radar. The above paragraph illustrates how the SBX design, for a given number of modules, trades off its electronic field of view in order to get a larger antenna aperture. The larger antenna gives both a narrower beamwidth (which improves tracking accuracy) and a greater tracking range (or equivalently a higher signal-to noise ratio at a given range) at a price of a limited electronic FOV. This decreased electronic FOV may not be a serious problem for a radar intended for testing, but can be a serious liability for an operational missile defense radar.

Which brings us to the LRDR. I was initially quite surprised to see that the MDA was requesting LRDR price estimates only at S-band, since I was expecting it to be at X-band. Since range resolution is roughly inversely proportional to bandwidth and bandwidth is roughly proportional to frequency, it would be expected that an X-band radar (about 9-10 Ghz) would have a range resolution roughly three times better than an S-band radar (2-4 GHz). (Frequencies much higher than X-band are precluded by atmospheric effects). Thus while an X-band radar might achieve a range resolution of 15-25 cm, an S-band radar might achieve only 50-100 cm, depending on the choice of frequency with S-band. Moreover, the newer U.S. missile defense radars (the TPY-2 and the SBX) already operate at X-band.

However, if the LRDR is strongly cost-constrained, than a large FFOV X-band radar may not be achievable. An X-band FFOV radar with the same range (that is, with the same P-A-G) as the SBX would have roughly 237,000 modules on an antenna with a diameter of about 10.5 meters. (This assumes the X-band modules are arranged as the same triangular array as on a TPY-2 radar antenna and have an average power 60% greater than the modules on the SBX.) It is far from clear that such a radar could be built for one billion dollars. As a point of comparison, a current-production TPY-2 X-band radar, with 25,344 modules, costs about $180 million with the antenna equipment unit alone costing about $140 million. Moreover, to deploy such a radar by 2020 without completely disrupting TPY-2 production would likely require a new module production line. Thus unless the LRDR’s P-A-G is much less than that of the SBX, it may not be possible to build it for $1 billion at X-band if it is a FFOV radar.

In this context, it is useful to compare the National Academy of Sciences (NAS) Report’s proposed “stacked TPY-2” radar proposal. This radar, which the NAS Report refers to as a GBX, has an antenna consisting of two TPY-2 antennas stacked one on top of the other, with 50,688 X-band modules. While it would essentially be a FFOV radar, it would only have about 1% of the power-aperture-gain product of the SBX, although the NAS Panel argues that is sufficient for the discrimination mission. The NAS Report estimates that it would costs between $0.8 and $1.0 billion to develop the GBX, and another $1.6 billion to buy five GBXs. Thus the cost of buying a only single GBX would be somewhat over $1 billion. If the NAS cost estimates are correct, this would suggest that such a stacked TPY-2 would be about the largest FFOV X-band radar that could be bought for $1 billion. For comparison, the NAS estimated the cost of developing and the building SBX to be about $1.4 billion, with another $0.3 billion subsequently spent on radar enhancements. (However, note that the cost of buying and modifying the SBX ocean-going platform for the SBX was itself nearly $0.25 billion, which is included in the above figure.)

Thus if cost is a key driver of the radar’s performance, and a power-aperture-gain product greater than that of a stacked TPY-2 is desired, then it may be necessary to go to a lower frequency or a LFOV antenna, or both. Assume an S-band frequency one third that of X-Band (say 3.17 GHz vs 9.5 GHz) and a FFOV antenna. In this case, for a fixed number of modules, the S-band radar will have an aperture nine times larger than the X-band radar, with about the same gain and beamwidth. All else being equal, the S-band radar would have a tracking range about 90.25 = 1.73 times greater than the X-band radar, or equivalently it would obtain a signal-to-noise ratio nine times greater at a given range. The actual advantage of the S-band radar might be considerably greater than this since the S-band modules are likely to have higher average powers than X-band modules available at the same time, and because the overall radar cross sections of warhead-shaped targets tend to decrease with increasing frequency. These advantages seem likely to overwhelm the additional cost due to the larger S-band antenna size, at least for a fixed, land-based radar.

A choice of S-band could also be consistent with the LRDR RFI’s stated interest in “leveraging the current and near-term production base.” With a 2020 deployment time frame, the LRDR could potentially use the same S-band modules planned for the missile defense antenna of the Navy’s new Aegis Air and Missile Defense Radar (AMDR). The first AMDR-equipped Aegis destroyer is scheduled to be procured in FY 2016 for deployment in about 2023. The S-band part of the AMDR will use new GaN modules that give greater power with less heat dissipation than current GaAs modules.  The timing of LRDR and AMDR radars would be consistent with the first batch of the new S-band modules going to the LRDR (and possibly the Space Fence).

To get a sense of the range of possibilities, it is interesting to look at some possible S-band radar configurations if the LRDR was required to have the same P-A-G as the SBX. If we assume the S-band modules have twice the average power of the current X-band modules (a complete guess) and a FFOV design with modules arranged on an equilateral triangular array with the same d/λ ratio as the X-Band TPY-2 antenna, then the required antenna would have about 90,500 modules on a diameter of about 19.4 m. (Compare to the 45,264 modules on a 17.8 m diameter for the SBX.)

The LRDR RFI’s explicit mention of a possible LFOV design for the LRDR raises the possibility that the number of modules could be reduced further, although presumably such an LRDR’s electronic FOV would be much wider than that of the SBX. Consider a design with a ± 30 degrees electronic FOV (with the modules on a square array). To have the same P-A-G as the SBX, such a radar would have about 46,200 S-Band modules on a diameter of 23 m. If the design included a second initially unpopulated face, the angular coverage could subsequently be doubled while keeping the initial cost down.

All of the above designs seem likely to exceed $1 billion in cost, suggesting that the LRDR might be built with a P-A-G significantly less than the SBX. Since there is roughly a factor of 100 difference in P-A-G between the SBX and NAS Report’s proposed stacked TPY-2, there is a lot of room for intermediate-sized designs.

While the discussion above is largely speculative, the seeming choice of S-band for the LRDR indicates that achieving the best possible range resolution is not the top priority for the LRDR design. Perhaps the MDA has decided that the range resolution achievable at S-band is adequate for discrimination given the perceived threat. Such a conclusion might be based in part on observations of tests. This would be a surprising conclusion, given that recent Defense Science Board and National Academy of Sciences reports have concluded that discrimination is still an unsolved problem, the same conclusion reached by outside analysts since at least the 1960s, and that it is unlikely that tests have been conducted against anything resembling the full range of possible countermeasures.

Perhaps there is some other reason for preferring S-band over X-band. However, if it a matter of a perceived need to hold the cost of the radar that is driving the frequency choice for the radar, the MDA may be settling for a less-than-optimal discrimination radar.

[1] The exception being the Cobra Dane radar on Shemya Island in the Aleutians, which was primarily built for gathering intelligence on Soviet ballistic missile tests.

[2] The radar in Clear, Alaska was not completed until about 2000. However, this radar was built by disassembling a PAVE PAWS radar in Texas that had been deactivated in the 1980s and the reconstructing it in Alaska.

[3] As originally built, these radars had tracking bandwidths of between 1 and 10 MHz (see my post of April 12, 2012) which would correspond to range resolutions of between 15 and 150 meters. It seems likely that these bandwidths were increased as part of the upgrades involved in incorporating them into the GMD system. However, this increase is limited by the total span of frequencies that the radars can operate over, which is 30 MHz (this span was not changed by the GMD upgrades). This would limit their maximum bandwidth to 30 MHz, corresponding to a range resolution of 5 m.

[4] The Cobra Dane radar is an exception to the above discussion. It operates at a higher frequency (about 1.3 GHz) than the other radars and has a minimum range resolution of about 1.14 m. (see this post of April 12, 2012 ) However, this high resolution is obtained only within 22.5 degrees of the antenna’s boresite. As noted in the text, Cobra Dane is poorly oriented for observing North Korean missiles, and a missile launched from North Korea towards the U.S. West Coast will never enter the radar’s high resolution part of its field of view.

[5] U.S. Department of Defense, “Missile Defense Agency Officials Hold a News Briefing on the Missile Defense Agency’s FY 2015 Budget,” March 4, 2014.

[6] U.S. Congress, National Defense Authorization Act for Fiscal Year 2014, Legislative Text and Joint Explanatory Statement to Accompany H.R. 3304, Public Law 113-66, Section 235, December 2013.

[7] Hearing of the Defense Subcommittee of the Senate Appropriations Committee, July 17, 2013.

[8] Missile Defense Agency, “Missile Defense Agency Long Range Discrimination Radar Request for Information,” SN HQ0147-14-R-0002, March 14, 2014. See https://www.fbo.gov/?s=opportunity&mode=form&id=42f1a95465dac067ca3ee0a665adf7f7&tab=core&_cview=1

[9] See the first letter under DRFP Documents, August 8, 2014 at the URL in note 4.

[10] See round 10 questions and answers at the URL in note 4.

[11] For the discussion in this paragraph, see section 3.3 of G. Richard Curry, Radar System Performance Modeling, 2nd ed. (Boston, Mass.: Artech House, 2005).

[12] Theodore C. Cheston and Joe Frank, “Phased Array Radar Antennas,” in Merrill Skolnik, ed., Radar Handbook, 2nd ed. (New York: McGraw-Hill, 1990), p. 7.21.

[13] Curry, page 33. Curry refers to this as the “acceptable element spacing.”

Update on Future Ground-Based Midcourse (GMD) Flight Tests (April 12, 2015)

An updated description of planned GMD flight tests (last update was post of April 17, 2013) as best as I can figure them out:

FY 2016: GM CTV-02+ (1Q FY 2016). This test replaces FTG-09, which was previously planned as an intercept test with a CE-II kill vehicle. The “+” indicates that the kill vehicle has the fix to the vibration problem that was demonstrated in the June 2014 FTG-06b test.[1] One purpose of the test is to “demonstrate the performance of alternate divert thrusters” that might be used in future kill vehicles.[2] One reason for developing the new thrusters is to reduce further the vibration problem involved in the failure of test FTG-06a in December 2010. The test is also intended to demonstrate “the end-to-end discrimination of a complex target scene including countermeasures.”[3] Although officially not an intercept test, the presence of a target raises the prospect that the interceptor might actually hit the target, as happened in FTG-02 in 2006, without running the risk of failing an intercept test.

FTG-15 (4Q FY 2016 -1Q FY 2017). This is to be the first GMD intercept test against an ICBM-range target (range greater than 5,500 km). It also will be the first flight and intercept test of the new production CE-II Block-I version of the Exo-Atmospheric Kill Vehicle (EKV). With one exception, all subsequent planned GMD intercept tests will be against ICBM range targets.[4]

FY 2017:

FTG-11 (4Q, FY 2017). This is to be the first salvo (multiple interceptors fired at a single target) test of the GMD system. In it, both a CE-I and CE-II equipped ground-Based Interceptors (GBIs) will be fired at a single ICBM-range target. In its 2014 annual report, DOT&E noted that this test would be the first opportunity to implement its recommendation that the CE-I EKV be re-intercept tested following the failure of FTG-07 in July 2013.[5]

FY 2018:

GM CTV-03 (3Q, FY 2018). This will be a non-intercept test of a two-stage version of the currently three-stage Ground-Based Interceptor.[6] Although the MDA has previously (in 2010) flight tested a two-stage GBI, this test will be of a new two-stage booster design derived from an upgraded design (C2) of the three-stage GBI. MDA is considering the possibility of deploying this two-stage booster with the Redesigned Kill Vehicle, potentially as early as 2020.

Designation unknown (FY 2018). Non-intercept flight test of the new Redesigned Kill Vehicle (RKV).[7] It is possible that this test could be combined with CTV-03. However, since MDA Director Admiral Syring has stated that in 2016 MDA will begin acquisition of two additional boosters for RKV testing, this seems likely to be a separate test.[8]

FY 2019:

FTG-17 (3Q, FY 2019). This is to be the first intercept test using the two-stage version of the GBI booster.[9]

Designation unknown (FY 2019). First intercept test of the new RKV.

FY 2020:

FTG-13 (3Q FY 2020). This will be the first GMD test against two near-simultaneous targets. In an operational test, two GBI interceptors (a CE-I and a CE-II) will attempt to intercept two targets with IRBM and ICBM ranges.[10] This test could be part of or coordinated with the BMDS Operational Test FTO-04 (which would likely involve a mix of Aegis, Aegis Ashore, THAAD and/or Patriot systems) which is also scheduled for 3Q FY 2020.

FY 2021:

FTG-12 (4Q, FY 2021). No additional information appears to be available about this test or the subsequent FTG-14. Both tests are listed in the DOT&E’s 2011 Annual Report.

FY 2022:

FTG-14 (4Q, 2022).


[1] Amy Butler, “Pentagon Plans Three Ambitious GMD ‘Firsts’,” Aviation Week and Space Technology, December 18, 2014.

[2] Prepared Testimony of J. Michael Gilmore, Director of Operational Test and Evaluation, Strategic Forces Subcommittee, Senate Armed Services Committee, March 25, 2015.

[3] Gilmore, Senate Armed Services Committee, March 25, 2015.

[4] Prepared Testimony of J. Michael Gilmore, Director of Operational Test and Evaluation, Strategic Forces Subcommittee, Senate Armed Services Committee, April 2, 2014; Prepared testimony of Admiral J. D. Syring, Defense Subcommittee, Senate Appropriations Committee, March 18, 2105.

[5] DOT&E Annual Report 2014, p. 312.

[6] Scott Maocione, “MDA Puts $51 Million in Budget To Develop Two-stage Booster,” Inside Defense SITREP, March 12, 2015.

[7] Butler, “Pentagon Plans”

[8] Prepared Statement of Vice Admiral J.D. Syring, Subcommittee on Strategic Forces, Senate Armed Services, March 25, 2015.

[9] Maocione, “MDA Puts $51 Million.”

[10] Butler, “Pentagon Plans;” Gilmore Prepared Testimony, 2014.

The Track Gate Anomaly: Does it also Affect CE-I Kill Vehicles? (August 15, 2014, revised 8/18/2014)

On Wednesday August 13, at the Space and Missile Defense Symposium, MDA Director Vice Admiral James Syring was one of the featured speakers. As Admiral Syring started to go through his slides, Aviation Week reporter Amy Butler began to photograph the slides. Even though the the slides were clearly marked “Approved for Public Release,” meeting organizers quickly stopped her, saying photographing of the slides was not permitted. However, before she was stopped she managed to photograph twelve of the slides and subsequently posted them on twitter (she tweets as @ABAviationweek). You can read her account about the slides and her (sucessful) attempt to ask Admiral Syring a question here:

The twelve slides that were posted are actually more detailed and interesting then those in your typical MDA briefing. Hopefully they will all soon be publicly available.

The slide that struck me as the most interesting was one titled “Track Gate Anomaly (TGA)” shown below:



“Informational Handouts” from MDA Environmental Impact Meetings Posted. (August 9, 2014)

The Missile Defense Agency (MDA) has begun holding a series of required public meetings as part of the Environmental Impact Review process for the proposed eastern U.S. Ground Based Midcourse (GMD) defense system interceptor site. The first meeting was held on Tuesday (August 5) in Ravenna Ohio. Apparently it was sparsely attended. You can read a description of the meeting here.

A number of other meetings will be held through August. The full list is here.

The MDA has posted its informational handout from the meeting here,

Two points from the handout struck me as noteworthy. First as the slide below suggests, MDA apparently believes that a few 10,000 km ICBMs now exist in the third world.


Second, the sites are being sized for up to 60 interceptors per site (3 x 20 launch silos). Given calls for expanding missile field 1 at Fort Greely Alaska from six to twenty silos, (which would bring the total in Alaska and California to 58 launch silos silos), this could indicate that we are headed for a total deployment of roughly 120 GBI interceptors in the not-too-distant future.

Lying Down on the Ground. It’s Almost as Effective as Iron Dome. And a Lot Cheaper. (July 24, 2014)

According to the Israeli Government, Iron Dome has been 85% effective (or perhaps a bit more) in destroying threatening rockets fired at its territory. However, each Iron Dome interceptor costs roughly $50,000-100,000, which adds up fast when there are a lot of rockets coming in. Moreover, a recent article in the Bulletin of Atomic Scientists by Theodore Postol challenges this claim, arguing that the evidence indicates that Iron Dome’s success rate in destroying the rockets is actually quite low.

On Sunday (July 20), another perspective on the threat posed by these rockets came out in the course of a hearing before the Israeli Supreme Court. The Court was ruling on a petition from several Bedouin and human rights organizations requesting that the Israeli government provide mobile bomb shelters to Bedouin villages in the Negev Desert. The court rejected the request, saying that the number of mobile bomb shelters was limited and that the government had prioritize where these were deployed.

A key argument made by the Israeli state attorney at the hearing was: “Bomb shelters are a last resort from a security perspective. Lying on the ground reduces danger by 80%.”

Imagine how effective an actual shelter would be.

(Actually, it is not clear how much either bomb shelters or lying down on the ground would actually help the Bedouins, since the warning sirens telling people to seek shelter apparently cannot be heard in many of the Bedouin villages.)

A Closer Look at the CBO’s Ground-Based Midcourse Defense (GMD) System Cost Figures (July 23, 2014)

The Congressional Budget Office has just released a very short report on the Missile Defense Agency’s future spending plans for its Ground-Based Midcourse (GMD) national missile defense system.[1] This Report, titled “Historical and Planned Future Budgets for the Missile Defense Agency’s Ground-Based Midcourse Defense Program” was released as a letter to Senator Jeff Sessions and is based on MDA’s budget request projections out through fiscal year 2019. It compares these GMD budget projections with actual GMD spending going back to FY 2008.

The main conclusions people seem likely to draw from the Report are that spending on the GMD system is expected to decline by more than a factor of two from its 2008 level and that by FY 2019 it will fall below $1 billion.[2] Specifically, the Report shows that GMD Research, Development, Test, and Evaluation (RDT&E) and GMD Procurement spending will total $789 million in FY 2019. Another $169 million for Operations and Maintenance (O&M) will bring the total FY 2019 GMD spending to $958 million. For comparison, the Report shows that in FY 2008 the total GMD spending was $2,093 million. (None of the $ figures in the Report have been adjusted for inflation.)

Several points should be made:

First the GMD budget falling below $1 billion is not a particularly significant benchmark (nor does the CBO Report say it is). According to the Report’s figures, actual FY 2013 spending on the GMD system was only $923 million.

Second, the actual planned spending on the GMD system will be significantly higher than shown in the CBO Report.[3] To illustrate this, I will focus on the planned GMD spending for FY 2019, the last year considered by the Report. As noted above, the Report says the currently planned GMD spending for FY 2019 is $958 million. However, if we look in more detail at the MDA’s planned budget we see that there are some significant omissions in what the CBO includes. For example, neither the Sea-Based X-Band (SBX) Radar ($63.0 million in FY 2019) nor the Long Range Discrimination Radar (LRDR) ($189 million in FY 2019) is included.[4] The FY 2019 GMD Test line item (Project MT08) included in the CBO cost figure is only $61.6 million.[5] Since each GMD test now costs $200 million or more, this suggests that roughly another $100-150 million for GMD testing should be included in the CBO’s FY 2019 GMD cost estimate figure.[6] A number of other projects that are intended to at least partially to contribute to the GMD system, such as the Common Kill Vehicle Technology Project ($54.3 million in FY 2019) are also not accounted for in the CBO figures.  Taken together, these omissions suggest MDA’s total planned spending for FY 2019 is much closer to $1.5 billion than the $958 million in the CBO Report.

Third, the numbers in the CBO Report are based on MDA plans that do not include a third interceptor site in the eastern United States. If this third site is not built, then by FY 2019, if everything proceeds according to plan, the GMD system would be nearly complete. All 44 planned GBI interceptors would be deployed, the Clear and Cape Cod radars would have been upgraded and incorporated into the system, and the LRDR would be nearly complete (with about $910 million spent on it through FY 2019). While there would certainly be significant ongoing costs, such as for operations, for testing (including buying new interceptors for this purpose) and for technology development and upgrades, one would certainly expect the GMD annual funding to be significantly less that it was FY 2008, when the system was in the midst of being built.

On the other hand, if a decision was made to proceed with a third interceptor site, the future GMD spending situation could look quite different.  The environmental impact statement for the proposed third site location will assess the deployment of between twenty and sixty interceptors at potential sites. If each interceptor cost the same as a current GBI interceptor, about $75 million, then the total cost just for the additional interceptors would be about $1.5-4.5 billion, which would require a large increase in GMD funding over current plans.

[1] Congressional Budget Office, “Historical and Planned Future Budgets for the Missile Defense Agency’s Ground-Based Midcourse Defense Program, letter to Senator Jeff Sessions, July 12, 2014. Available at: http://www.cbo.gov/sites/default/files/cbofiles/attachments/45546-GMD_Program.pdf.

[2] See for example, Jason Sherman, “CBO Traces Decline in GMD Spending From FY-08 To FY-19,” Inside Defense SITREP, July 23, 2014.

[3] The CBO Report (footnote a) states that the Report only includes funding in the Midcourse Defense program element and does not include “funding for other support activities that are contained in other program elements.”

[4] MDA’s planned budget can be found on pages 2a-xxi to 2a-xxiv of http://comptroller.defense.gov/Portals/45/Documents/defbudget/fy2015/budget_justification/pdfs/03_RDT_and_E/2_RDTE_MasterJustificationBook_Missile_Defense_Agency_PB_2015_Vol_2.pdf.

[5] This is not just an FY 2019 budget anomaly, as the FY 2015-2019 five year average for the GMD Test line item is $67.4 million.

[6] Most of this other GMD testing funding is likely in the Ballistic Missile Defense Test ($413 million in FY 2019) and the Ballistic Missile Defense Targets ($429.8 in FY 2019) program elements, which are not included in the CBO GMD cost figures.

Next Ground-Based Missile Defense (GMD) Intercept Test Could Be as soon as June 22. (June 6, 2014)

It appears that the next intercept test for the Ground-Based Midcourse national missile defense system is planned for Sunday, June 22 between 9:00 am and 1:00 pm U.S. east coast time. The target will be launched from Kwajalein in the Marshall Islands and the interceptor from Vandenberg Air Force Base in California

On Wednesday (June 4), Reuters cited two anonymous sources that the test, designated FTG-06b, would be held on June 22.[1]

However, today (June 6), the Pacific Islands News Association reported that, according to a warning issued by the U.S. Army, the planned test time was Monday June 23 between 4:00 am and 8:00 pm. The backup dates are June 24 and 25.

These two announced dates are not inconsistent because the of the 19 hour time difference between California and Kwajalein. Thus 4:00 am to 8:00 am on the 23rd at Kwajalein corresponds to 9:00 am to 1:00 pm on the 22nd in California. MDA usually specifies the date and time of a test using the time zone of the interceptor launch location. On the other hand, the U.S. Army warning was presumably intended for the local population near the target launch location, and thus likely uses Kwajalein time.

Thus from a U.S east coast perspective, the planned interceptor launch time is Sunday June 22 between 9:00 am and 1:00 pm.

This test is the third intercept test of the new CE-II version of the GBI interceptor’s kill vehicle. The previous two CE-II intercept tests failed, although a successful flight test not using a target was successfully conducted about a year ago.

If this upcoming test is successful, MDA will likely be able to almost immediately resume production of the 14 additional GBI interceptors it plans to deploy in Alaska by the end of 2017. A failure, depending on its cause, would likely impose significant delays on any future deployments of CE-II interceptors and may make the end of 2017 deadline impossible to achieve. It is now over 41 months since the most recent CE-II intercept test attempt, which failed.

[1] Andrea Shalal, “U.S. Missile Defense Test Could Shift Timing to Add Interceptors,” Reuters.Com, June 4, 2014

First Test Launch for Aegis Ashore (May 21, 2014)

The Missile Defense Agency announced today that it had conducted its first test launch of an Aegis SM-3 missile defense interceptor from an Aegis Ashore facility similar to the one planned to be operational in Romania by the end of next year. The test, using an SM-3 Block IB version of the interceptor, was conducted at the newly completed Aegis Ashore test facility in Hawaii and was described as successful. No target missile was used, and thus there was no intercept attempt.



GAO on DoD’s GMD Testing Options Report (May 1, 2014)


The Government Accountability Office (GAO) yesterday (April 30, 2014) released a Report assessing a Department of Defense (DoD) Report on options for the test program of the Ground-Based Midcourse Defense (GMD) national missile defense system. Specifically, the DoD Report, mandated in the National Defense Authorization Act for FY 2013, was required to:

(1) Explain GMD testing options if the forthcoming FTG-06b intercept test did not successfully demonstrate that the problem that caused the failure of the new CE-II kill vehicle in the FTG-06a test has been resolved; and

(2) Assess the feasibility, advisability, and cost effectiveness of accelerating the pace of GMD test flights.

The DoD Report was released to Congress on October 18, 2013, but does not yet appear to be publicly available (at least I haven’t seen it). Yesterday’s GAO Report is based on a briefing given by GAO to Congress on December 16, 2013.



Before discussing the GAO’s findings, some background information:

The GMD interceptors, thirty which are based in silos in Alaska and California, use two different versions of the Exo-Atmospheric Kill Vehicle (EKV). The original Capability Enhancement 1 (CE-I) version of the EKV was flight tested five times from 2005 to 2010, three of which were intercept tests, and all of these tests were reportedly successful. However, the CE-I EKV design was not sustainable, and thus the Missile Defense Agency (MDA) began in 2004-2005 to develop a new CE-II EKV.

CE-II interceptors began deployment in 2008, and currently make up about ten of the thirty deployed interceptors. However, the CE-II interceptor was not flight tested until 2010, when two intercept tests failed. The failure of first CE-II intercept test (FTG-06) in January 2010 was subsequently assessed as being due to a quality control failure in assembling the EKV, a relatively easily correctable problem. However, the second failure, FTG-06a in December 2010, posed a much more serious problem, since it was eventually determined to be due a design flaw in the kill vehicle. Specifically, the problem was attributed to excessive vibrations in the kill vehicle’s inertial measurement unit caused by the kill vehicle’s divert rocket motors, which are used to steer the kill vehicle towards its target.

As a result of the FTG-06a failure, deliveries of CE-II interceptors were suspended until a solution to this problem was demonstrated through a successful CE-II intercept test. In addition particular, deliveries of the fourteen additional interceptors announced in March 2013 cannot begin until after such a successful CE-II intercept test. Determining the cause of and developing a fix for the FTG-06a problem has been complex and difficult, and this problem has so far delayed successfully demonstrating a CE-II capability by more than three years and significantly increased the cost of doing so.[1] In January 2014, MDA conducted a successful flight (not intercept) test of CE-II interceptor with mitigations for the FTG-06a problem and could conduct a CE-II intercept test (FTG-06b) as early as the third quarter of FY 2014.

However, the CE-II testing situation is further complicated by the failure of the FTG-07 intercept test in July 2013. This test, using a CE-I interceptor, was intended to test the many changes that have been made to the CE-I kill vehicles since they have been deployed. Although the failure review for this test is still ongoing, the failure has been traced to the CE-I kill vehicle’s battery system.[2] Because the battery system is the same in both the CE-I and CE-II kill vehicles, it is possible that FTG-06b will be further delayed until this problem is fully resolved.

Overall, since MDA began flight testing operationally-configured GMD interceptors in 2005, it has conducted ten GMD flight tests, seven of which involved an intercept attempt. Thus the GMD system has been averaging about 1 GMD flight test per year but only about 0.7 intercept tests per year. Some in Congress have been urging MDA to increase this rate of testing, and, in particular, to increase to it to an average pace of 3 flight tests every two years. As discussed in my post of December 24, 2012, MDA has been opposed to increasing the pace of flight tests beyond the current average of one per year.


What did the GAO conclude?

(1) The GAO Report states that the DOD Report provides “limited insight on potential testing options” if the upcoming FTG-06b CE-II intercept test fails. The GAO Report noted that DoD Report presented only one alternative testing option – the development of new divert thrusters that produce less vibration. (By attempting to reduce the vibrations at their source, this approach is complimentary to the one being taken in the FTG-06b test, which instead attempts to isolate the inertial measurement unit from the vibrations). While the GAO characterizes this option as “reasonable,” it states the DoD Report provides few details on how or when such new divert thrusters could be developed and tested, on the cost, benefits and risks of this option, or of its impact on both currently deployed and future production interceptors.

The GAO also noted that prior to the failure of the FTG-07 CE-I test in July 2013, DoD also had testing options involving CE-I interceptors available to address the CE-II test failures. However, the GAO stated the FTG-07 failure precluded MDA from employing these options until the root cause of that failure is both identified and resolved.

(2) It has previously been reported that the DoD Report had concluded that an increase in GMD flight test pacing to three tests every two years was not feasible. (See my post of February 13, 2014.) The GAO Report provides more details on this issue. Specifically it states that the DoD Report says that “With additional funding, it should be possible to accelerate GMD’s testing pace to three flight tests every two years beginning in fiscal year 2018.” However, the GAO Report then goes on to state that it defines “feasibility” as “the extent to which something is both possible and likely to occur,” and that it judges that it is ”not likely” that the pace of testing could be accelerated. According the GAO, the DoD Report also provides no information on either the advisability or cost effectiveness of accelerating the testing pace. (However, it is clear from previous statements by MDA and DoD officials that they do not regard an acceleration of testing as either advisable or cost effective – see my post of December 24, 2012).


[1] The GAO Report states that the total cost of conducting a successful CE-II intercept test had now risen from $1.17 billion (as of August 2012) to $1.31 billion (as of June 2013), primarily due to increased failure review costs. Prior to the failure of FTG-06 in January 2010, this cost had been expected to be about $236 million.

[2] John Liang, “DoD: Faulty Battery Caused July 2013 GMD Intercept Failure,” Inside the Pentagon, April 3, 2014.


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