Why Modular Makes Sense
The evolution of the Enterprise ’s concept of operations and systems over the past five decades offers an important insight for future ship and aircraft development. Substantial volume, reserve electrical power, and a small number of integral warfare systems were needed to address the warfighting requirements of the Enterprise . Those characteristics coincidently made it easier to adapt the Enterprise ’s capability over time. In contrast, most of today’s ships and aircraft were designed in the latter days of the Cold War, with limited reserve capacity and integral systems of sensors, processors, and weapons for the entire range of high-end missions against the Soviets: antisubmarine warfare (ASW), integrated air and missile defense (IAMD), antiair warfare (AAW), surface warfare (SUW), and strike. Although those complex platforms (and our superb sailors) have adapted to new missions over the past 20-plus years, most of our ships and aircraft remain fully loaded “luxury sedans,” taking their full multimission kit with them wherever they go through their whole service lives.
Navy missions since the Cold War evolved to include defeating terrorists, pirates, and illegal traffickers; preparing to counter mines and armed small boats; providing humanitarian assistance/disaster relief; and building partnership capacity to take on maritime-security missions. Those operations show one limitation of a highly integrated luxury-car platform. While the ship, aircraft, and crew might flex to new or different missions, it does so at a cost. Destroyer crews are challenged to maintain proficiency in core missions such as ASW, SUW, and IAMD when engaged in months-long counterpiracy operations. Amphibious ships are in high demand for counterterrorism and humanitarian-assistance operations and have had limited opportunity to practice amphibious assault. And P-3C crews had their ASW capabilities atrophy after a decade of high-tempo intelligence, surveillance, and reconnaissance operations over land.
To more efficiently match platform to mission in the future we will need to treat capabilities as being inherent in the payloads a platform carries and employs, rather than capabilities being inherent (integrated) in the platform itself. In Sailing Directions and Navigation Plan for 2013 , I highlighted my intent to “expand the reach and effectiveness of ships and aircraft through new payloads of weapons, unmanned systems and sensors.” The use of modular payloads that can be changed out over a platform’s life offers an effective and affordable way to maintain our adaptability and warfighting advantage against evolving threats.
The Precision-Weapons Revolution
The predominant trend compelling us to consider a new approach for capability development is the exponential growth of information-processing power. Over the past 40 years, that growth helped fuel innovation in almost every civilian and military technology, and brought about a revolution in the precision and accuracy of sensors and weapons. In 1965, Gordon Moore, co-founder of Intel, predicted that the number of transistors per processor chip would double about every two years, thereby increasing overall computing speed and power. His prediction—now commonly referred to as “Moore’s Law”—held true. Today’s commercially available chips are almost 40,000 times faster than those available in 1971. 1 Moreover, the average price of a megabyte of computer memory has gone from more than $700,000 dollars in 1970 to around 2 cents today. 2
The precision weapons enabled by this computing power fundamentally changed modern warfare. Advances in targeting and guidance systems allow us to achieve much greater accuracy and lethality with far fewer weapons. Today, about 70–80 percent of guided munitions fall within ten yards of their targets. During World War II only 18 percent of U.S. bombs fell within 1,000 feet of their targets. 3
Our commanders exploit this precision by using the smallest number and size of weapons possible. In addition to improving efficiency, this minimizes collateral damage—which can have a significant strategic impact in modern counterinsurgency operations. From World War II to the Gulf War, the number of bombs used to hit a fixed target decreased by a factor of 300, the number of aircraft assigned decreased by a factor of almost 400, and bombing accuracy improved by a factor of 17. 4 Instead of sorties per aimpoint, we now commonly speak in terms of aimpoints per sortie.
The ability of a few very-precise standoff weapons to be more efficient and effective than a larger number of less-precise weapons leads to a surprising result. In modern warfare, precision standoff weapons such as Tomahawk or the joint standoff weapon are now more cost-effective in many situations than short-range gravity bombs such as the joint direct attack munition (JDAM). A Tomahawk missile, for example, costs about $1.2 million, while a JDAM is about $30,000. To strike a single target, however, the total training, maintenance, and operations cost to get a manned aircraft close enough to deliver the JDAM is several times higher than the cost of launching a Tomahawk at the same target from a destroyer, submarine or aircraft operating several hundred miles away. That is one of the trends leading us to focus more effort on improving and evolving our standoff sensor and munition payloads.
The Limits of Stealth
The rapid expansion of computing power also ushers in new sensors and methods that will make stealth and its advantages increasingly difficult to maintain above and below the water. First, though, military sensors will start to circumvent stealth of surface ships and aircraft through two main mechanisms:
• Operating at lower electromagnetic frequencies than stealth technologies are designed to negate, and
• Detecting the stealth platform from angles or aspects at which the platform has a higher signature.
U.S. forces can take advantage of those developments by employing long-range sensor, weapon, and unmanned-vehicle payloads instead of using only stealth platforms and shorter-range systems to reach targets.
Stealth ships and aircraft are designed to have a small radar or infrared electromagnetic signature at specific frequencies. The frequency ranges at which stealth is designed to be most effective are those most commonly used by active radar or passive infrared detection systems. At lower frequencies detections do not normally provide the resolution or precision necessary for accurate targeting. Using more powerful information-processing, however, military forces will be able to develop target-quality data from these lower-frequency passive infrared signals or active-radar returns. 5
The aspects at which stealth platforms are designed to have their smallest signature are those from which detection is most likely. For example, an aircraft or ship is designed to have a small signature or radar return when it is approaching a threat sensor—or has a “nose-on” aspect. Improved computer processing will produce new techniques that can detect stealth platforms at target aspects from which they have higher radar returns. Multiple active radars, for instance, can combine their returns through a battle-management computer so radar detections from a stealth platform’s less-stealthy side, underside, or rear aspect can be shared and correlated to allow the stealth platform to be detected and attacked. Similarly, passive radar receivers can capture the electromagnetic energy that comes from transmitters of opportunity—such as cell-phone or TV towers—and bounces off a stealth platform at a variety of angles. With better processing in the future, those weak, fragmented signals can be combined to create actionable target information. 6
Those developments do not herald the end of stealth, but they do show the limits of stealth design in getting platforms close enough to use short-range weapons. Maintaining stealth in the face of new and diverse counterdetection methods would require significantly higher fiscal investments in our next generation of platforms. It is time to consider shifting our focus from platforms that rely solely on stealth to also include concepts for operating farther from adversaries using standoff weapons and unmanned systems—or employing electronic-warfare payloads to confuse or jam threat sensors rather than trying to hide from them.
Faster Refresh, Exploiting the Learning Curve
The average time required to research, develop, and construct a new U.S. ship or aircraft is now more than 15 years, or about eight cycles of Moore’s Law. For example, the Arleigh Burke -class destroyer took 14 years from initial requirement to the lead ship’s commissioning. That by itself is not necessarily a problem. Most of our ship and aircraft classes will be in service for decades. We should retain a deliberate, comprehensive, and effective process to design them from scratch.
Meanwhile, rapidly improving information-processing has sped up the technology “refresh” cycle. Consumer electronics are completing a generation every one to two years, and we tapped into that faster innovation cycle over the past decade with some of our off-the-shelf technology insertion efforts in surface-ship and submarine combat systems. Those initiatives, however, work at the “payload” scale, rather than on a whole platform.
Payloads offer a more rapid means to improve or integrate new capabilities into a proven platform. In contrast to the 15 to 20 years to design and deliver a new ship or aircraft, a prototype or demonstration weapon, sensor, or unmanned-vehicle payload has been developed, assembled, and installed on an existing platform in as little as a few months. In Bahrain, we are outfitting our patrol coastal ships with Mk-38 gyro-stabilized guns and Griffin antiship missiles within nine months of the decision to upgrade; in the Mediterranean, we integrated the Fire Scout unmanned air vehicle on frigates and used it for surveillance during Operation Unified Protector in Libya; and in the Middle East, within six months of identifying a need, we outfitted our deploying helicopters with upgraded Mk-54 torpedoes.
Payloads also offer a more cost-effective way to integrate capability into today’s platforms. The cost of ships and aircraft has risen by as much as 500 percent (in constant dollars) since the mid-1960s. Much of that increase is due to the inherent complex capabilities built into our platforms, not the hull or airframe itself. But once the requirements for a new ship or aircraft are locked down and the ship goes into production, the builders’ learning curve enables each successive hull or airframe to be built for less cost than its predecessor. Some recent examples of this are the Virginia -class submarines, for which the builder reduced the number of construction man-hours by 30 percent from the first hull to the most recent, or Arleigh Burke -class destroyers, where cost dropped by more than 20 percent between the first and second flight. Keeping a proven hull or airframe in serial production for as long as possible gives us the largest (and longest) return on our research-and-development investment.
Taking advantage of that learning curve while ensuring each hull or airframe has relevant capability for its time requires that we look at platforms more as trucks. The truck will load and plug in successive generations of modular payloads as it goes through decades of serial production. To support that approach, we would increasingly employ standardized interfaces to plug in new sensors, weapons, and unmanned systems; and standardized links to communicate with them if they leave the truck. The design of future platforms also must take into account up front the volume, electrical power, cooling, speed, and survivability needed to effectively incorporate new payloads throughout their service lives.
Focusing on payloads is not a completely new idea, and the Navy has pursued payload-centric capability development in the past. In most cases, however, those projects adapted a purpose-built platform, as opposed to designing a ship or aircraft from the keel up to host changing payloads. In 1994, for example, the concept of a stealthy arsenal ship loaded with large numbers of land-attack cruise missiles was proposed, but after two years of analysis it was deemed unaffordable and terminated. About the same time, as a result of the 1994 Nuclear Posture Review the Navy removed four Ohio -class SSBNs from service. Seeing an opportunity to continue using those ships, in 2002 the Navy began converting them into guided-missile submarines—SSGNs. The adaptation allowed the SSGNs to carry new payloads of missiles (up to 154 Tomahawk land-attack cruise missiles, or TLAM) and special operations forces (SOF), effectively becoming an arsenal ship.
Today we are planning to replace the SSGNs’ TLAM capacity when they retire with the Virginia payload module (VPM), integrated into Virginia -class SSNs already in serial production. VPMs will be designed to host a variety of payloads beyond TLAM to include large-displacement unmanned underwater vehicles and SOF operators and their systems. VPMs will more than triple the missile capacity of our current Virginia -class SSNs (from 12 to 40 TLAMs) and provide access from inside the submarine to service VPM payloads.
We also have taken a payload-centric approach in some aspects of surface-ship design. Armored box launchers for Tomahawk missiles were fielded in the early 1980s on battleships and nuclear-powered cruisers. This system evolved into the Mk-41 vertical launching system (VLS) introduced on Ticonderoga -class cruisers in 1986 and retrofitted on some Spruance -class destroyers. VLS is a modularized below-deck launcher with standard cell sizes and standard interfaces for power, cooling, and computing. This standardization allowed rapid integration of new weapon payloads over the ships’ life. Aboard cruisers, VLS payload options expanded from TLAM in 1986 to now include the standard missile family (SM-2, SM-3, and SM-6) and ASW rockets (ASROC). VLS is the main battery of Arleigh Burke -class destroyers, and in addition to SM-family missiles and ASROC now includes the Evolved Sea Sparrow Missile for short-range air defense. Today, 8,372 VLS cells are deployed in the U.S. surface fleet, each of which can hold a growing range of payloads. VLS is also deployed in 11 allied navies, providing opportunities to “pool” weapons and other payloads in Europe or East Asia for all VLS users. This is a cost-effective model to integrate new payloads aboard proven platforms and well worth the upfront investment in ship power, cooling, and standard interfaces.
We also are in the early stages of incorporating unmanned payloads on our manned ships to further expand their reach on, above, and below the sea. Starting in 2005, we began equipping amphibious ships (LPDs, LSDs, and LHAs) and destroyers with the Scan Eagle UAV under a services contract for maritime and littoral intelligence, surveillance, and reconnaissance (ISR). Operating for up to 15 hours at a nominal range of 50 nautical miles from its host platform, Scan Eagle provides critical and unobtrusive day and night imagery in support of counterterrorism, counterpiracy, surface warfare, and irregular warfare missions—as well as helping to uncover other illicit activities at sea.
The MQ-8B Fire Scout vertical take-off UAV debuted in 2009 aboard frigates to support a range of ISR missions, including service in Operation Unified Protector in Libya and in support of counterpiracy operations around Africa. We will introduce an improved MQ-8C (Fire–X) UAV next year that uses a helicopter airframe with greater range and capacity—allowing it to conduct surveillance and strike missions in support of special-operations forces. The control systems for Scan Eagle and Fire Scout can be removed and reinstalled in a relatively short time for deployment, making them an effective way to rapidly change the capability of the host platform.
Aircraft naturally lend themselves to a payload focus, because they are designed with hard points and junctions into which a number of modular payloads can be connected. The F/A-18 Hornet, for example, can carry a wide range of weapons or sensors, from antiship Harpoon missiles and targeting pods to antiair advanced medium range air-to-air missiles. Similarly, the P-8A Poseidon maritime patrol aircraft will be able to carry torpedoes, Harpoon missiles, bombs, and sonobuoys that can evolve over time to address changing threats or incorporate new technologies.
Those examples are certainly moving us in the right direction. We will continue to work to decouple payload development from platform development and design platforms from the start to accommodate a changing portfolio of payloads. This will allow us to build the same hulls and airframes for decades and exploit the industrial learning curve while still evolving our capabilities to keep our warfighting edge against improving adversaries. In particular, we need longer-range weapons to allow platforms to reach our foes despite their improvements in sensors. We need more capable and more numerous electronic-warfare and cyber payloads to thwart detection and targeting. We need unmanned payloads that expand the reach of today’s platforms both for sensing and attack. And we need volume in our platforms to accommodate the people and equipment for new missions.
Our first “keel up” application of a payload focus is the littoral combat ship (LCS). The heart of the LCS’s payload flexibility is its interface-control document (ICD). That ICD specifies how payloads plug into ship computer networks, power, and cooling, and describes the space available to host new payloads and operators. Similar to the USB port on today’s personal computers, the ICD provides a common reference for payload developers seeking to design mission packages for an LCS. We are currently developing surface warfare, mine warfare, and antisubmarine warfare mission packages for the LCS. With the ICD, the payloads within these mission packages can evolve over time to take advantage of new technologies or to address new threats.
We plan to send the Freedom (LCS-1) to Singapore early next year to evaluate the LCS operational concept, including the SUW mission package, in a relevant operational environment. The adaptability of the LCS to new payloads allows us to adjust the systems in the mission package based on the lessons learned from this deployment and future operations. We will need to be disciplined in modifying payloads, however, to avoid introducing new cost increases through too-frequent modifications.
We will use reserve capacity and standardized interfaces to introduce a range of payloads in new platforms such as the mobile landing platform (two of which will be built to serve as an afloat forward staging base), joint high-speed vessel, and P-8A. We will also look to employ a changing set of payloads on our existing amphibious ships, destroyers, aircraft carriers, and submarines.
Affordably Keeping Our Warfighting Edge
Decoupling the development of payloads from the development of platforms is an imperative for us to take advantage of the fundamental trends shaping our operating environment. Technology, especially information-processing, will continue to evolve more quickly and become more widely available, while new ship and aircraft classes likely will continue to require more than a decade to join the Fleet. We appear to be reaching the limits of how much a platform’s inherent stealth can affordably get it close enough to survey or attack adversaries. And our fiscal situation will continue to require difficult trade-offs, requiring us to look for new ways to control costs while remaining relevant.
Common hulls and airframes will decrease and stabilize shipbuilding and aircraft construction costs through the learning curve of serial production. At the same time, shifting to modular payloads as the primary source of capability enables us to more rapidly and affordably incorporate new technology. Just as Apple’s fleet of platforms has provided incentives for the development of new ‘apps’ and peripheral devices that easily plug into its operating system, the Navy can spur the development of new capabilities and payloads to plug into the Fleet. This model will help us to maintain our warfighting edge, build the Fleet capacity that keeps us forward, and improve our readiness for today’s missions. We will work together with our industry partners to put this concept into action, so our Navy can continue to sustainably protect our nation’s security and prosperity.
2. See www.jcmit.com/memoryprice.htm  and Dave Bursky, “Nonvolatile Memory Cuts the Price of Digital Storage,” Electronic Design , 21 January 2002, 25.
3. Robert A. Pape, “The True Worth of Air Power,” Foreign Affairs , 83.2 (2004) 116.
4. Richard P. Hallion, Storm Over Iraq (Washington, DC: Smithsonian Press, 1992) 190. See also Paul G. Gillespie, Weapons of Choice: The Development of Precision Guided Munitions (Tuscaloosa: University of Alabama, 2006).
5. Bill Sweetman, “Stealth Threat,” Popular Science , December 2001, www.popsci.com/military-aviation-space/article/2001-12/stealth-threat  . See also Arend G. Westra, “Radar versus Stealth,” Joint Forces Quarterly , 55 (2009) 136–143.
6. Bill Sweetman, “Stealth Threat,” Popular Science , December 2001, www.popsci.com/military-aviation-space/article/2001-12/stealth-threat  . See also Arend G. Westra, “Radar versus Stealth,” Joint Forces Quarterly , 55 (2009) 136–143.