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CHAPTER ONE Department of Defense Materials Needs GENERIC DEFENSE NEEDS As the United States, its institutions, and its citizens interact throughout the world, situations may arise that call for military force. To safeguard its interests for the foreseeable future the United States must be able to project military power around the globe.1 Today, the United States is far and away the greatest military power in the world and is far ahead in using new technologies in military systems. Because oceans surround the United States, it has in place a worldwide base structure to support forward-deployed forces. Whereas other nations tend to operate from their own territory, as a matter of strategic principle the United States projects military power over long distances with medium-range and short-range systems. The oceans form a buffer over which the United States maintains military control. The buffer is not impermeable, though. It can be penetrated by long-range missiles, space-based systems, and submarines. The present capability of the United States to project military power around the globe came about mainly as a result of U.S. participation in World War II, which left an infrastructure of U.S. military bases around the globe to support treaty obliga- 1 Most of the information in this section is based on presentations to the committee by Andrew Marshall, director, Office of Net Assessment for the Secretary of Defense: Marshall, A., “Overview of DoD Vision and System Needs,” paper presented to the Committee on Materials Research for Defense After Next, National Research Council, Washington, DC, February 15, 2000; Marshall, A., “Overview of DoD Vision and System Needs—An Update,” paper presented to the Committee on Materials Research for Defense After Next, National Research Council, Washington, DC, January 29, 2002.
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tions and mutual-defense agreements. In the aftermath of the Cold War, the infrastructure of overseas bases has been largely dismantled, partly to reduce costs and partly because many host countries no longer accept a powerful U.S. presence on their soil. The closing of overseas bases affects all of the Armed Forces, but especially the Army and the Air Force. The Navy, in effect, brings its overseas bases with it in the form of the fleet, taking advantage of freedom of the seas to move about the world. Low-cost, highly capable commercial technologies are increasingly enabling many nations, including some with very limited resources, to mount regional threats based on precision strikes from their own territories. It is recognized that in the next 20 to 30 years, the period of interest for this study, even ships of the U.S. fleet might be threatened in the home waters of most nations, though submarines can be expected to remain relatively invulnerable. The possibility that even resource-constrained nations will be able to acquire potent offensive capabilities—though of limited range—increases the vulnerability of overseas U.S. bases. The following core tasks therefore lie ahead for the U.S. military: Projecting long-distance military power; Maintaining capability to fight far away; Coping with the eroding overseas base structure; Safeguarding the homeland; and Adjusting to major changes in warfare, including joint-service operations, coalition peacekeeping, and an increased number of humanitarian missions. The following trends in warfare are expected to continue: The need will increase for a precision strike force that can maneuver rapidly and effectively and can survive an attack while far away. The force must be able to conceal its activities from an enemy while detecting enemy activities. Advances in information technology will increase coordination among forces. Global awareness through real-time networked sensors and communications will facilitate command and control and enable precision strikes. Using unmanned vehicles, information will be gathered in new ways, military power will be delivered remotely, and the risk of casualties will be reduced.
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Fighting in urban areas will increase, requiring entirely different strategies and equipment. Guerilla warfare will require new strategies and weapons. Marshall and other speakers also focused the committee’s attention on new threats that could not be counteracted by force projection.2 Weapons of mass destruction, for example, are a growing threat. During the Cold War, when nuclear weapons, principally in the Soviet Union, were a major concern, U.S. security was safeguarded by strategic deterrence to neutralize that threat. Among threats to the United States may be the delivery by missile or other means of small numbers of nuclear, chemical, or biological weapons from very disparate sources, including terrorist groups, or an assault on the complex web of information systems that are becoming increasingly important in the delivery of goods and services. Vulnerable infrastructure points include power grids and dams. The terrorist acts of September 11, 2001, highlight the need to address such threats.3 Marshall and others urged that the United States maintain its capability to project military power over long distances, harness advancing technologies to maintain its technological lead as long as possible (recognizing that other nations will be working to counter U.S. capabilities), continue to control the ocean buffer, and make effective plans for safeguarding the homeland. EXAMPLES OF SYSTEM NEEDS Briefings by senior officials of the Armed Services, defense agencies, and other government agencies covered a variety of short-term and long-term perspectives. The starting point for the fundamental needs of the U.S. Army, Michael Andrews, deputy assistant secretary of the Army for research and technology, said, was that though it would continue to be based in the United States the army would have to be able to respond 2 Vickers, M., “The Revolution in Military Affairs (RMA),” paper presented to the Committee on Materials Research for Defense After Next, National Research Council, Washington, DC, February 15, 2000; Henley, L., “The Revolution in Military Affairs After Next,” paper presented to the Committee on Materials Research for Defense After Next, National Research Council, Washington, DC, February 15, 2000. 3 National Research Council (NRC). 2002. Making the Nation Safer: The Role of Science and Technology in Countering Terrorism. Washington, DC: National Academies Press.
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quickly to provide a global presence.4 Quick response would necessarily be provided by airlift, which implies lightweight forces. The Army has a goal of being able to move a large concentration of troops anywhere in the world in 48 hours. Because it anticipates that armored and airborne forces will continue to be essential for attacking an enemy, the Army will emphasize highly mobile lightweight vehicles equipped with next-generation armor and stealth to survive against high-intensity threats. Infantrymen face increasingly potent weapons and require a very high degree of information connectivity on the battlefield. Currently, each soldier must carry heavy personal equipment and batteries. In the future, the Army plans to reduce each soldier’s load by using lighter-weight equipment, low-power electronics, and robotics offloading. The Air Force also envisions supporting its military power projection from the United States.5 According to Kenneth Harwell, chief scientist for the Air Force Research Laboratory, the goal is to deliver munitions from the United States to targets anywhere around the globe in less than an hour.6 This will require both very high speeds and very lightweight material. Meeting this goal carries a formidable technical challenge. The Air Force also envisions the need for increased emphasis on space assets. To fulfill its objective of decisively influencing events on land anywhere at any time, the Navy wants systems that are stealthy and can operate in littoral areas around the world.7 The Navy is emphasizing antisubmarine and mine warfare to ensure that the U.S. fleet can carry out its mission in inshore waters. The goal of the Marine Corps is to provide very lightweight, agile, early-entry forces, operating from sea bases with minimal needs for logistic 4 Andrews, M., “Army Vision and S&T: Accelerating the Pace of Transformation,” paper presented to the Committee on Materials Research for Defense After Next, National Research Council, Washington, DC, February 15, 2000. 5 Delaney, L., “Air Force Modernization,” paper presented to the Committee on Materials Research for Defense After Next, National Research Council, Washington, DC, February 15, 2000. 6 Harwell, K., “Air Force Research Laboratory: Technology Vision,” paper presented to the Committee on Materials Research for Defense After Next, National Research Council, Washington, DC, February 16, 2000. 7 DeMarco, R., “Department of the Navy Science and Technology—Materials: Today, Tomorrow, and the Future,” paper presented to the Committee on Materials Research for Defense After Next, National Research Council, Washington, DC, February 15, 2000.
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support ashore.8 The Marine Corps will be a strike force, not an occupying force. All the military services expressed a need for systems that cost less and require less maintenance. The principal delivery hardware—ships, submarines, aircraft, and vehicles—will probably be expected to remain in service for very long periods, placing new demands on underlying technologies for durability, maintainability, and ease of upgrade. The Air Force was particularly forceful in stating the case for aircraft with very long service lives and the need to maintain and modernize aircraft at much lower cost. TRANSLATION TO MATERIALS AND PROCESS NEEDS Though presentations to the committee were organized by the needs of individual services, materials needs are related to more generic systems, platforms, and equipment. For example, because all the services require aircraft, materials research that leads to more advanced aircraft will be valuable to all the services. Although the need of a particular service might be the impetus for meeting a defined capability, once a technology matures to the point that it can be readily used in an operational system, it may also be used advantageously in similar systems for other purposes. Ships, submarines, aircraft, military vehicles, sailors, airmen, soldiers, and marines of the future will all need advanced materials that enable significant changes in maneuverability (mobility, speed, agility); force protection (from nuclear, biological, chemical, kinetic, or explosive weapons through stealth, identification, armor, and active defense); engagement (highly concentrated and sustained firepower); and logistics (durability, maintainability). Advanced materials must satisfy diverse requirements for speed, strength, precision, survivability, signature, materials selection, cost, weight, and commonality. Ships may be able to travel at speeds in excess of 75 knots; very lightweight tanks will travel at speeds up to 75 miles per hour; weapons will be delivered at hypersonic speeds. Materials will have 8 Gray, A., “Thoughts on Future Marine Corps Materials Needs,” paper presented to the Committee on Materials Research for Defense After Next, National Research Council, Washington, DC, February 15, 2000.
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to endure tougher environments for longer periods—from ocean depths to Arctic cold to desert heat to space reentry. For example, the Army envisions new high-strength, very lightweight materials that can be integrated with primary structures and can defend ground vehicles against future weapons. The Army seeks to field systems with an offensive capability similar to the M1A2 Abrams tank at about one-third the weight; these may include unmanned ground vehicles and munitions. Materials processes will require greater precision compatible with reduced fabrication and operational tolerances. Increased survivability will require materials that can reduce multispectral signatures (e.g., radio frequency, thermal, acoustic) and provide ballistic protection. The cost of acquisition and lifetime support of DoD platforms and war fighters must be reduced. For example, precision munitions will not be completely effective until they are inexpensive enough to be used by even the lowest tactical unit. Materials that increase capability but also increase cost must be compared to materials that provide current capabilities at reduced costs, including maintenance and upkeep costs. Because manpower is the single largest DoD cost, materials that reduce the need for manpower will be extremely beneficial. Materials that reduce weight but retain functionality will permit increases in payload and range. It will be necessary to use common materials across platforms, between services, and among soldiers, sailors, airmen, and marines. The services can all benefit from processes that encourage sharing of materials technologies. Desired Materials Properties DoD needs various types of functionality, alone and in combination, for military systems. This section describes types of materials, combination of materials properties, and engineering issues that new materials must address in defense systems. R&D in materials and processes will be required to improve existing materials and achieve breakthroughs in new materials and combinations. Examples of the types of materials needed are as follows: Lightweight materials that provide equivalent functionality. A pervasive requirement for DoD systems is weight reduction, in everything from tanks to the equipment carried by each soldier. Yet, military forces
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will require at least the same functionality as today’s systems—for example, the ability to withstand enemy fire—as well as new functionalities—particularly in sensing surroundings, communicating with and responding to other elements of the force, increasing lethality, and responding to new threats. Materials that enhance protection and survivability. It will remain critical for DoD forces to be able to withstand enemy fire. Research must be done on new approaches to providing this capability, particularly at reduced weight. Materials that perform multiple functions are a promising area of research. Stealth materials. As the range of operations increases, it will be increasingly important for some elements to remain invisible for as long as possible using stealth technologies. This is an important area of research, particularly in multifunctional structural materials that incorporate a stealth capability and electronic and/or optical materials and devices that may actively respond to probes to achieve invisibility. Electronic and photonic materials for high-speed communications. Communication and coordination of elements in tomorrow’s force will require extremely broad bandwidth and secure transmission, reception, and interpretation. These, in turn, will require materials that will enable these functions, be they optical, electronic, or some combination thereof. In addition, the force elements will be under constraints on weight, speed, or both—meaning that the desired functionality must be achieved in very small volume with as little weight as possible. Sensor and actuator materials. A battlefield of interconnected elements poses many demands, one of which is the need to detect signals that may be of many types. Research on sensor and actuator materials and their integration into larger systems will be critical to DoD. An emerging area of need is detection of chemical and biological agents. High-energy-density materials. There is a need for explosive materials that have higher energy per unit mass than current explosives, the properties of which can be tailored to maximize lethality against specific threats. Similarly, successful R&D on new high-energy-density propellants could make it possible to decrease the mass and increase the range of projectiles. Materials that improve propulsion technology. Improved propulsion will be necessary on land and sea, in air and space. The numerous materials issues this raises range from the need for high-energy-density
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fuels to materials for improved undersea propulsion. Materials for hypersonic propulsion systems are a priority for future Air Force systems. Materials Characteristics In addition to the materials needs already discussed, a number of other materials properties are desirable for DoD systems. These characteristics cut across all the classes of materials that have been mentioned. Although they would not of themselves lead to the selection of a particular material for a given application, they are likely to affect that selection. Examples of these characteristics are as follows: Multifunctionality. One way to reduce weight and volume is by using materials that can perform at least two functions (e.g., stealth and structural support). Multifunctionality can be thought of on two scales: (1) mesoscopic (e.g., coatings) or macroscopic (e.g., load-bearing), and (2) microscopic or nano, in which multiple physical phenomena are produced through molecular design or architectural texture. The concept of multifunctionality encompasses many classes of materials and applications: Structural materials may be self-interrogating or self-healing, provide stealth, or protect against enemy fire; microscopic materials or systems may combine sensing, moving, analyzing, communicating, and acting. Self-healing and self-diagnosing. Materials with self-healing and self-diagnosing characteristics address a number of DoD needs, from improving survivability to minimizing system maintenance. The advantages and concomitant savings are obvious. Low total system cost. Cost is a primary criterion for DoD decisions for the foreseeable future. Materials that result in low total system cost (including initial, operating, maintenance, and disposal costs) will have a decided advantage, even if their cost is high relative to other choices. Low maintenance. Because systems for Defense After Next are likely to be in use for many decades, materials that do not require extensive, active maintenance are clearly preferred. An example is the Navy’s critical need to reduce the necessity of paint chipping, a resource-intensive task that adds significantly to the Navy’s manpower requirements. High reliability. The consequences of materials failure in DoD systems can be dire. The need for materials and manufacturing processes that are highly reliable spans all classes of materials.
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Environmental acceptability. DoD has become increasingly sensitive to the environmental impact of military activities. The use of environmentally friendly energy sources and the efficient use of power are areas where R&D is needed. Materials and processes for DoD systems should have as little adverse impact on the environment as possible. An area of special concern is the decommissioning and disposal of obsolete systems, including the recycling and reuse of as much of an old system as possible. Engineering Issues Successful research on broad classes of materials and processes will affect future defense systems only if other engineering issues are considered. The issues discussed below must be considered concurrently with R&D because they are likely to reveal the directions that such research should take. Design Methods The successful introduction of a new material into a system requires that the material chosen be integrated with the design of the entire system. Conversely, early in the design process, the design can be modified to compensate for the shortcomings of a material. Comprehensive databases of material properties would greatly facilitate the design of materials. Characterizing materials by desired properties, an essential aspect of materials design, may require new techniques. Materials by Design If system designers and materials and process experts communicate early in the process, it may be possible to design or tailor a material to meet the needs of the system, rather than designing the system around available materials. In fact, this is likely to become more common as strategic experiments, coupled with validated physical models, are incorporated into computer simulations that enable the virtual exploration of composition, structure, processing, and properties as a partial replacement for extensive laboratory experimentation. A move in this direction would also reduce development time and cost. The properties of a given material are seldom ideal for all aspects of a particular application. Materials and process scientists must be aware of the desirability of materials or combinations of materials with properties
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that can be tailored to be compatible with a variety of system requirements. The concept of treating multiple materials as a system (e.g., in structural composites) has already been shown to increase the tailorability of materials substantially. The ability to tailor materials in multiple dimensions or more quickly than has previously been possible should also open new doors. Influence of Materials on Development and Deployment Costs The choice of a material can affect development and deployment costs in many ways. First, the cost of raw materials may be an issue, particularly if it is very high. If a material is extremely difficult to process or if there is a great deal of waste or rejected material, costs can also escalate quickly. Creating an entirely new processing technology or qualification procedure is also a cost factor. It is critical that the baseline process, the range of acceptable properties, and other factors governing these costs be understood early on so that the research program can perhaps tailor the research to respond to them. Availability of Commercial Alternatives Buying a material or a part will almost always be cheaper than designing, building, and manufacturing a new one specifically for DoD. In some cases, the quality of the commercial product may even be better, thanks to economies of scale and quality controls. Before DoD invests in developing a new material or process to improve performance, the improvement should be shown to have a potential payoff high enough to be worth the investment. A crucial aspect of DoD’s investments in the development and acquisition of the best materials in the future will be choosing between in-house development, collaboration with industry, or purchase. Risk Management For obvious reasons, DoD is highly risk averse. In the materials and process arena, risk aversion translates to a reluctance to introduce new materials or processes unless the benefits have been clearly demonstrated and the risk is acceptably low. Minimizing risk implies minimizing the number of materials in use and identifying materials that simplify component or system design, which could reduce cost and risk—assuming, of course, that the material meets all of the other risk minimization criteria. Finally, DoD must constantly be on the lookout for fatal flaws that could
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eliminate a material from consideration no matter how desirable its other characteristics might be. Manufacturing A new material or process that seems very promising in the laboratory may be useless because it is not manufacturable. Materials and process scientists must ensure that production of the material or component can be scaled to a level appropriate for its end use. Defect density must be acceptably low and the yield high so that there is little or no waste or inefficiency in the process. It must be possible to inspect and characterize the product, either through rigorous process-based quality approaches or standard inspection. Finally, the product must be manufacturable at an acceptable cost. Life-Cycle Issues How a material will perform over the life of the component or system is an essential consideration in choosing a material for a particular application. If there is a predictive reliability model for a material or process, the expected lifetime for the material in use can be easily determined. An alternative would be a self-interrogating, self-reporting material or system that indicates when attention is required. Materials incorporated into DoD systems must be highly reliable. This can be ensured in a number of ways, ranging from selecting materials with important properties that persist over a wide range of conditions to rigorous process-based quality that allows for confident prediction of reliability. The components and systems must be maintainable so that they can function at specification for many years, if necessary. All life-cycle costs, including the cost of maintenance, must be considered. Finally, what will happen at the end of system life must be considered, taking into account recycling or reuse of as much of the system as possible and environmentally conscious disposal of the rest.
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