Management of the limited Tomahawk inventory always has been a challenge. Now, with the expenditures in Operation Iraqi Freedom, the Tomahawk supply chain is seriously at risk. Congress undoubtedly will appropriate supplemental funds to replenish those missiles used in Iraq, but these—the new Tactical Tomahawk—will not reach the fleet in tactically significant numbers for two to three years. Until then, the fleet will have to make do with markedly fewer missiles than it would like.
Even after delivery of the replenishment missiles, relief will be temporary. With any future operational expenditures, and the retirement of the remaining Tomahawk Block III missiles starting in 2013, there is another budgetary and inventory "train wreck" in the making. The opportunity to avoid this predicament is on us now, and it is fleeting. At the same time, it provides us the chance to design a transformational weapon system that meets the Navy's requirements in the next decade—a long-range cruise missile that could be even more affordable, compatible with all launch platforms (air, surface, and subsurface), and incredibly responsive.
The Tomahawk Inventory at Risk
We have no immediate way of replenishing the missiles used in Iraq. The Navy last ordered new Tomahawk Block IIIs in 1997 and the production line is shut down. There is an ongoing effort to convert the older Block IIs and the obsolete antiship version of Tomahawk into Block IIIs, but this upgrade does not significantly increase active inventory numbers. The Block IV Tomahawk, also known as Tactical Tomahawk, has just begun technical and operational testing and will not be delivered to the fleet in meaningful numbers until 2006. Efforts to accelerate these initial deliveries from a new production line will be difficult.
At the root of this precarious situation was a procurement decision that seemed logical when made in 1998—to shut the Block III production line and use budgeted Tomahawk funds to pursue a new version, Tactical Tomahawk. The goal was noble: provide a more affordable and more capable missile within the existing budget. At the time, the risk of shutting down the Block III line was the subject of considerable debate, but in the end it was considered a low-risk move with a high payoff. No one could have predicted the war planner's affinity for Tomahawk and the resultant increased operational use. We had expended only 400 missiles in the eight years prior to 1998; we have since used more than 1,400 in half the time. The obvious lesson is not to shut the production line until you can deliver something else. Still, we could not have fully funded Tactical Tomahawk development unless we shut the line.
How can we, in the face of fiscal realities, further inventory pressure, and evolving requirements, better manage the transition to what comes after Tomahawk and avoid leaving the future war fighter without this vital capability?
What We Know about the Future
In 2013, the Tomahawk Block III missile is scheduled to begin retirement as many of the missiles' components near the ends of their estimated service life. All Block IIIs will be retired by 2020, or sooner, depending on operational use. Remanufacturing this version is not likely to be a cost-effective option as it would require replacement of many expensive components, rocket motors for example, that will have exceeded their service life. It likely would be just as economical to buy new Tactical Tomahawks.
If we buy Tactical Tomahawks at the rate reflected in the current future-year defense program, we barely will keep up with Block III retirements. To continue to make progress toward a reasonable inventory, that rate would have to be doubled after fiscal year 2010. This would mean a significant increase in the Tactical Tomahawk procurement budget. The replacement of expenditures, as the result of operations in Iraq or any future conflict, also has to be added to this requirement.
Certainly, buying more Tactical Tomahawks would help mitigate the inventory problem in the near term, but it is doubtful the Navy could afford to both achieve acceptable inventory levels and replace the Block IIIs as they retire. Unless we prepare an alternative, we will be forced to continue to buy Tactical Tomahawk beyond 2013, even if the capability and number we can afford are less than we need.
What We Need to Find Out
Besides the inventory deficiencies, there are other reasons to meet this challenge head-on now. First, the Tactical Tomahawk design will be 15 years old in 2013, and, although designed to be maintained in the inventory for up to 30 years, it will be expensive to continue to manufacture. This will be mainly the result of component obsolescence; such is the nature of today's commercially driven technology cycle. Even as Tactical Tomahawk is finishing developmental testing and beginning low-rate initial production, some components in the original 1998 design no longer are available and will necessitate design changes or "life-of-type" buys.1 This is an issue that every program plans for, and most manage successfully. As time goes on, however, it gets harder. By 2013, the availability of the commercial parts, outdated manufacturing processes, and the limited number of qualified suppliers might cause the Tactical Tomahawk's price to rise significantly.
The most important reason to consider our future alternatives is the ever-evolving warfighting requirement. What capability will we need in the next decade? How many times can we use this weapon system before our potential adversaries wise up and learn how to defend themselves? The conventional long-range cruise missile concept could benefit from a rigorous capability requirements study, including an objective analysis of alternatives.
The Tomahawk Block III was developed when our process for generating and validating our future requirements was less mature, and although modernized, is mostly an outgrowth of the original nuclear variant of Tomahawk. Performance was based more on what we could make the design do than on what we needed it to do. The Tactical Tomahawk operational requirements document was finalized more than a year after the program started, and to great extent, was forced to repeat the already-awarded contract specification. Tomahawk nevertheless has earned a vital place in our long-range strike arsenal, but prudence now requires that we revisit and validate the Navy's need for a "Tomahawk like" weapon in the face of what we do not know about the future. We do not know how long Tactical Tomahawk will continue to meet our capability needs, or even what those future needs could be.
It is important, from both the intersecting perspectives of cost and capability, that we ask these questions now. If the Navy did want another option to consider in 2013, the budgeting system and the acquisition process dictate that a decision be made no later than the 2006 budget planning cycle.
Tactical Tomahawk
Tactical Tomahawk is a resounding success thus far. Initial flight testing has been nearly flawless. At less than half the cost of a Block III, if we could buy one today, Tactical Tomahawk will most likely continue to exhibit comparable utility for many years after its initial operational capability next year. We need to field as many as we can as quickly as we can.
Still, Tactical Tomahawk will have been at sea for nearly ten years by fiscal year 2013 and, except for warhead upgrades, will have the same capability it has today. It does bring some new mission capability: two-way data link, bomb damage indication, and loiter. However, when compared tactically to the Block III, it may not be the quantum leap that some think it is and may not continue to meet all our needs in the next decade.
Tactical Tomahawk will have a limited capability against time-sensitive targets. Unlike an armed unmanned aerial vehicle or the unmanned combat aerial vehicle, Tactical Tomahawk cannot be recalled, and its ability to loiter over the battlefield is limited by its relatively short endurance. Scenarios where it would be launched and then directed somewhere other than its primary target seem unlikely. It is more probable that this limited asset will continue to be used against high-priority, long-dwell targets that will not change in priority during the missile's transit time. In addition, using Tomahawk in a high-threat environment usually necessitates detailed mission planning and means a deliberate, non-time-critical mission. These issues argue that the subsonic Tactical Tomahawk may never be an adequate weapon against time-sensitive targets whose dwell time may be measured in minutes.
The Next Generation Cruise Missile
"Sea Power 21," the Chief of Naval Operations' vision for 21st-century naval forces, is an articulate and coherent construct from which to shape our Navy. It suggests specific future technologies that would be required to implement its capabilities. Most notable is Admiral Vern Clark's inclusion of hypersonic missiles.2 The question is: What is the case for hypersonic missiles? As most program managers know, if one does not begin with, and maintain, a clear focus on a rigorously validated warfighting requirement, programs based on even the most promising technology initiatives will fail.
While it is not clear to me exactly what operational analysis forms the basis for Admiral Clark's highlighting of hypersonic missiles, the linkage to DoD participation in the National Aerospace Initiative is evident. A DoD and NASA partnership, the National Aerospace Initiative aims to overcome the technical barriers to high-speed flight. The intent is that NASA would benefit from the development of reusable "access to space" technology and DoD could capitalize on technology off-ramps that would support warfighting applications such as rapid long-range strike, reconnaissance, and high-speed stand off weapons. "Sea Power 21" supports this initiative by including hypersonic missiles as a desired future technology.3 It clearly has initiated the debate about what comes after Tomahawk.
The expectation is that by 2013, improvements in command, control, communications, computers, intelligence, surveillance, and reconnaissance (C4ISR) will shorten the "detect–locate–identify–decide" portion of the target kill chain significantly. If we believe these efforts will be successful, the "strike" side also must be shortened if we are to maximize the return on investment in C4ISR. If the entire kill chain is to be measured in minutes, then weapon responsiveness must emulate the detect–locate–identify–decide process times. That requires that the shooter already be very near the target or that weapon fly-out time be exceedingly fast. Long-range, time-sensitive targets are where the high-speed cruise missile could pay off, particularly in a high-threat environment.
It takes a Tomahawk more than an hour to fly to a target 600 nautical miles distant. It would take a Mach 6 cruise missile about ten minutes to do the same. This would be tactically useful for several reasons. First, time-sensitive targets in a high-threat, antiaccess scenario could be engaged at stand-off ranges. If the missile had enough range, it would allow surface and subsurface launch platforms as well as tactical aircraft to prosecute these targets, increasing force flexibility. Second, in any scenario, time-sensitive targets could be engaged over a much larger area with a minimum number of launch platforms. When compared to the area able to be covered at subsonic platform speed or by subsonic standoff weapons, the ten-minute area coverage of an F/A-18 could be expanded approximately 40 times. If we need the ability to put ordnance anywhere, any time, in minutes, then the long-range, high-speed cruise missile could be a very cost-effective tool, particularly if it is sea based. This type of weapon would be very effective in enabling the Navy's Global Concept of Operations.4
It is counterintuitive to think you could go faster with a cheaper design, but technology is evolving and this may be very achievable. For example, ramjets and emerging scramjet technology, because of their simple design when compared to supersonic turbojet technology, promise economic producibility and a significant reduction in missile unit cost. Precision guidance continues to become cheaper to buy. These two subsystems represent major cost drivers in the Tactical Tomahawk design. In addition, manufacturing techniques continue to improve. There is no reason to believe these weapons cannot be made affordable.
Given the extremely low level of the U.S. Air Force's conventional air-launched cruise missile (CALCM), it is imperative that a next generation cruise missile program addresses a CALCM follow-on as well. The next generation cruise missile should be as the Joint Strike Fighter is to manned aviation—joint.
So what would a follow-on to Tactical Tomahawk and CALCM look like? A comprehensive requirements analysis must be completed—there may be some significant cost-versus-capability trades generated that could change how we think about the long-range cruise missile—but a good guess might be:
- Interoperable—compatible with all probable launch platforms: air (Air Force and Navy), surface, subsurface
- Responsive—able to kill targets at very long ranges within minutes after receipt of target coordinates with very simple mission planning
- Accurate—as good or better than global positioning system accuracy
- Lethal—effective against traditional Tomahawk targets to include hard and deeply buried, mobile, and above-ground soft targets
- Affordable—significantly lower procurement cost than Tactical Tomahawk, the current benchmark
- Survivable—survivable in a high threat environment
3. Engineers generally define "hypersonic" as Mach 5 and above, supersonic as Mach 1-4. NASA needs very high Mach numbers to get to orbit. At nominal target ranges, a weapon benefits less from very high Mach numbers. This would lead one to conclude the NASA and DoD requirements—one based on orbital mechanics, one based on threat—could diverge in the case of a cruise missile. The definition of "affordable" also is problematic, one application being reusable, the other expendable. This said, the fundamental challenges in material science and propulsion are on the same technology road map. back to article
4. VAdm. Mike Mullen, USN, "Global Concept of Operations," U.S. Naval Institute Proceedings, April 2003, pp. 66-69. back to article