Coming into this off-cycle budget expectations were that an Administration that had shown, for lack of a better term, restrained enthusiasm, towards missile defense on the campaign trail would seek to shut the program down as part of its cost-saving plans. Indeed, with the SECDEF’s announcements on 6 April where some very high profile and expensive systems, like the F-22 and FCS, were identified for termination, it seemed this would also be the case with missile defense. This past Thursday, 8 May, MDA released its budget submission as part of the overall DoD submission where it not only identified vertical cuts (i.e., programs terminated) but expansion of other programs and new directions for research,
development and deployment as part of the package.
Up front, the ground-based mid-course program that provides protection to the homeland remains, but in altered form as emphasis will be placed elsewhere. Essentially, when 30 interceptors are in the ground (26 at Ft. Greely, Alaska and four at Vandenberg AFB, CA) the GBI program will enter a sustainment phase. All told, 44 missiles will be produced with the newer missiles replacing the older ones already on alert and those missiles being refurbished either as new alert missiles or used in tests for reliability and evolutionary capability growth, much like the current Minuteman program.
Programs identified for cuts, specifically, KEI (Kinetic Energy Interceptor), MKV (Multiple Kill Vehicle) and a second ABL (Airborne Laser) aircraft, had basis in one or more areas – namely the threat as developed or forecast and technological or prospective operational shortcomings. In almost every case, save MKV, the operational environment of the terminated program was boost phase intercept. While we have discussed the boost phase of intercept previously, it is worth touching on again, if for nothing else than to set the stage for what follows.
Of the three previously identified phases of ballistic missile flight – boost, mid-course and terminal, boost phase was at once the most alluring from an operational viewpoint and yet one of the most technically (and operationally challenging) goals. Unlike mid-course and terminal, the target size, complexion and vulnerability were greatest in the boost phase. In that phase, the missile is quickly located and identified by overhead IR assets (like DSP) and fed into the BMDS for cueing to forward-based and -deployed sensors (like AN/TPY-2 and Aegis BMD) for tracking by radar. Even as it stages, the missile’s size and trajectory offer up a more visible target than a much smaller, colder RV against the cold of space or one reaching terminal velocity on re-entry. In this configuration, intercept, via either laser or kinetic kill was thought to take advantage of the period of greatest vulnerability to the missile. As it climbs through the atmosphere, significant aerodynamic loads are placed on the airframe such that the slightest damage incurred would likely lead to catastrophic failure.
While that looks plausible on paper, the reality is another matter. Boost phase presents a number of technical and operational obstacles to overcome. Consider those faced, for example, by an airborne laser. Assuming it is able to acquire and track a threat (which implies it is already on station and in range) the weapons beam must travel a significant distance through the atmosphere and strike the target with enough energy to punch a hole through the missile’s skin and lead to a propellant vent or induce some other structural damage. In that journey, the same atmosphere that bends and reflects visible, RF and infra-red waves will be acting on the beam, requiring constant feedback and adjustment from the targeting aircraft. This requires exceptionally sophisticated optics, tracking and control hardware and software, one example of which is the deformable mirror in the laser weapon. It is axiomatic that the more complex a system, the greater the chance of disruption stemming from failure of a minor part – even something as mundane as incremental debrading of optics would impact beam quality and effectiveness on target. Conversely, hardening of missiles (while acknowledging concurrent penalties in weight and payload/range tradeoffs) by the use of steel vice aluminum, faster/high impulse burns to minimize thermal exposure of the missile or even reflective/ablative coatings might be sufficient to safely convey the missile past the laser threat window.
Operationally, there are significant challenges to the ABL as presently defined. Since the main weapon is a chemical-based laser, large quantities of extremely toxic (and very exotic) fuel must be both forward-staged for on-deck refueling and carried aloft, turning the aircraft into effectively a flying EPA super-fund site and all that implies for host-nation staging. More so, however, are the additional support measures required for stationing and employing such an aircraft. Absent exceptionally granular OPINTEL on launch location, time, threat, etc., one presumes that in a threat environment the theater commander would expect to have ABL in a continually manned station for instantaneous response. Simple back-of-the-envelope calculations figure on a requirement for 4 to 5 aircraft to keep one on station. But that’s not all – since the ABL is what is known as a “high-value unit” (or HVU) similar to other high-demand/low volume platforms (like AEW or ISR aircraft), airborne and surface assets will have to be diverted to protect it. Since threat missiles typically originate well within hostile territory (“denied territory”), to minimize the distance the ABL would have to close the launch area as much as possible, placing it at higher risk of interdiction.
Similar issues are, or were, faced with the employment and deployment of KEI. To be most effective KEI would have to be mobile or at the very least, transportable. Again, given host nation constraints, the prospects of KEIs rumbling around the countryside during increased tensions are not a measure likely to diffuse said tension. Even so, the intercept windows would be smaller for a strictly land-based variant while a sea-based variant has additional complexities in the area of size and handling (especially if the propellant is hypergolic).
So while boost phase may be considered a bridge too far at this point (and we haven’t even tested the ABL in a full weapons test yet – that is this fall), there is promise in the ascent phase with both existing and future technology. Why ascent phase? Ascent phase is that portion of flight from completion of boost and prior to apogee. In that period a number of factors are present which are promising for intercept – the missile remains unitary and no RV’s or counter-measures have deployed, the airframe is still heated from its atmospheric passage and as such, is more “visible” and most importantly, it has traveled further down range that interceptor platforms are able to engage from a further distance, leveraging off networked, over-the-horizon sensors. This might, for example, open up possibilities for SM-3 Block II or even the Block Ib. Intercept tests have been performed where Predator UAVs have tracked the ascending missile, opening up more possibilities for persistent ISR in support of missile defense. As we have advocated here before, it wouldn’t be much a further stretch to envision a low observable UCAV armed with high-power microwave missiles use the localized-EMP effects of those missiles to render useless the guidance control of an ascending missile causing to enter an un-commanded pitch or roll maneuver causing it to break up in flight.
So, one may now add ascent phase to the aforementioned three phases of flight, with defense goals as follow:
- Boost: detect, track
- Mid-course(Ascent): Detect, track, discriminate, intercept
- Mid-course(Descent): track, discriminate, intercept
- Terminal: intercept
The value of such a schema is its applicability across the BMD spectrum – for not only is ascent phase intercept an option for the strategic realm, but also for regional or theater threats. And it is those realms that MDA is re-directing effort to address, something a growing number of missile defense supporters have been advocating. For while the threat implicit in the IRBM possibilities of an Iranian Safir or ICBM in the form of an improved Taepo dong-II is not to be discounted, what cannot be ignored is the ever growing inventory of short- and medium-range missiles being fielded against our overseas allies, partners and our own forces. Whether it is a large number of relatively unsophisticated SCUD or Shahab missiles or a CSS-5 variant anti-ship ballistic missile, there is no denying the threat has grown quantitatively and qualitatively, and absent international régimes to stem the rising tide of proliferation and control dual-use technology, ballistic missiles remain a growth industry.
Up next – Arms Control and BMD: Are the Two Incompatible?
Article Series - Missile Defense 101
- Missile Defense 101: Intro
- Missile Defense 101 – ICBM Fundamentals
- Missile Defense 101 – The Threat
- Missile Defense 101: Sensors (Pt I)
- “To Provide for the Common Defense…”
- More Cold War Secrets Revealed
- Multiple Kill Vehicle (MKV) Completes Hover Test
- Missile Defense – It’s Not Just for ICBMs
- Iran’s Successful Space Launch
- Observations of a Missile Launch – I
- Missile Defense and FY10 DoD Budget
- Speaking of Ascent Phase Intercept…
- Foreign Ballistic Missiles – Capabilities and Threat Guide
- Say Hello to Ashura
- Required Reading: Naval War College Review Articles on China’s DF-21/ASBM
- BMDR Release and BMD Deployments to the Gulf
- Iran Announces New Space Launch Vehicle (SLV)
- Airborne Laser Testbed Successful in Lethal Intercept Experiment
- Wednesday’s Roll-up of Missile Defense News
- Aegis BMD: “Build a Little, Test a Little, Learn a Lot”
- The Problem With Proliferation: Cruise Missile Edition
- Sea-Based BMD — Another Successful Test
- Flightdeck Friday: A BMD Primer
- The Missiles of Spring: 2012 Edition