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US-NAVY-Experimental-Laser
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America’s ability to project conventional power abroad is eroding swiftly as state and non-state actors acquire advanced capabilities to offset the U.S. military’s strengths across all operating domains—air, land, sea, space, and cyberspace.
Potential adversaries are pursuing guided weapons and other sophisticated systems that are designed to threaten the U.S. military’s freedom of action and its overseas basis. Moreover, many of these threats, particularly precision-guided cruise and ballistic missiles, are on balance less expensive and easier to replace than the expensive kinetic weapons the U.S. military relies on to defend against them. As a result, America’s future power projection operations may be far more challenging and inordinately more costly compared to conventional operations that it has undertaken over the last twenty years.
To change this emerging dynamic, the Department of Defense should invest in new technologies that will help the U.S. military retain its freedom of action and create cost-exchange ratios that favor the United States. Throughout history, technological breakthroughs such as machine guns, armored vehicles, submarines, precision-guided weapons, and stealth aircraft have proven to be great sources of operational advantage for militaries that were willing and able to exploit them. This report addresses the potential of a new family of emerging technologies known as directed energy (DE) to achieve similar results.
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The Center for Strategic and Budgetary Assessments (CSBA) is an independent,
nonpartisan policy research institute established to promote innovative thinking
and debate about national security strategy and investment options. CSBA’s goal is
to enable policymakers to make informed decisions on matters of strategy, security
policy and resource allocation.
CSBA provides timely, impartial and insightful analyses to senior
decision makers
in the executive and legislative branches, as well as to the media and the broader
national security community. CSBA encourages thoughtful participation in the development
of national security strategy and policy, and in the allocation of scarce
human and capital resources. CSBA’s analysis and outreach focus on key questions
related to existing and emerging threats to U.S. national security. Meeting these
challenges will require transforming the national security establishment,
and we
are devoted to helping achieve this end.
.
America’s ability to project conventional power abroad is eroding swiftly as state
and non-state actors acquire advanced capabilities to offset the U.S. military’s
strengths across all operating domains—air, land, sea, space, and cyberspace.
Potential adversaries are pursuing guided weapons and other sophisticated systems
that are designed to threaten the U.S. military’s freedom of action and its
overseas basis. Moreover, many of these threats, particularly precision-guided
cruise and ballistic missiles, are on balance less expensive and easier to replace
than the expensive kinetic weapons the U.S. military relies on to defend against
them. As a result, America’s future power projection operations may be far more
challenging and inordinately more costly compared to conventional operations
that it has undertaken over the last twenty years.
To change this emerging dynamic, the Department of Defense should invest
in new technologies that will help the U.S. military retain its freedom of action
and create cost-exchange ratios that favor the United States. Throughout history,
technological breakthroughs such as machine guns, armored vehicles, submarines,
precision-guided weapons, and stealth aircraft have proven to be great
sources of operational advantage for militaries that were willing and able to exploit
them. This report addresses the potential of a new family of emerging technologies
known as directed energy (DE) to achieve similar results.
.
Thus, this report has two principal objectives. The first is to examine DE as one
particularly promising source of operational advantage for the U.S. military. The
unique attributes of future DE capabilities—the ability to create precise, tailorable
effects against multiple targets near-instantaneously and at a very low cost
per shot—have great potential to help the Department of Defense (DoD) break
from a program of record that continues to procure increasingly expensive military
technologies with diminishing operational returns. For example, in future
conflicts with capable enemies possessing large inventories of guided missiles, it
may be operationally risky and cost-prohibitive for the U.S. military to continue
to rely exclusively on a limited number of kinetic missile interceptors. Such a
“missile competition” could allow an adversary to impose costs on U.S. forces
by compelling them to intercept each incoming missile with far more expensive
kinetic munitions.
There may be less resource-intensive options that could help the United States
to maintain an advantage in such conflicts. Offensive and defensive DE capabilities,
including high-energy lasers and high-power microwave weapons, could
provide U.S. forces with nearly unlimited magazines to counter incoming missiles
at a negligible cost per shot. When integrated with kinetic capabilities to
support new operational concepts such as AirSea Battle,2 these DE weapons could
help reverse the cost-imposition calculus of future missile competitions in favor
of the United States. U.S. forces could also use DE capabilities to gain a significant
advantage over opponents capable of launching swarms of fast attack craft;
armed unmanned aircraft; and guided rockets, artillery, mortars, and missiles
(G-RAMM). Moreover, DE systems could help counter these threats with significantly
less collateral damage than that caused by kinetic defenses, an attribute
that would be especially important during future operations in urban terrain.
The report’s second objective is to assess emerging DE technologies that
have the potential to transition to real-world military capabilities over the next
twenty years.
In the mid term (the next five to ten years), it may be possible to use mature
laser technologies to create deployable, ground-based weapons to defend forward
bases against aircraft, G-RAMM, and ballistic missiles. Because of their
potential to overcome the size, weight, and magazine depth challenges posed by
current technology chemical lasers, new electrically powered, solid-state lasers
(SSLs) may be the most promising alternatives for laser weapons that can be
mounted on large mobile platforms such as surface naval vessels. Given sufficient
resources, it may also be feasible in the mid term to develop high-power microwave
(HPM) emitters carried by aircraft or cruise missiles that could degrade,
damage, or destroy the electronic hardware that enables enemy anti-access/
area-denial (A2/AD) threats.
In the long term (the next ten to twenty years), it is expected that technological
advances will continue to reduce the volume, weight, and cooling requirements
of high-power SSLs, creating opportunities to integrate them into small aircraft
and tactical ground vehicles. By the late 2020s, it may also be possible to develop
ship-based free electron lasers (FELs) with power outputs sufficient to interdict
more hardened targets, including ballistic-missile reentry vehicles.
Although DoD is pursuing science and technology (S&T) initiatives related
to these concepts, it is likely that many, if not most of them, will remain at the
conceptual level or will be terminated after their initial demonstrations. The
lack of institutional support for DE concepts has a number of causes. Previous
high-profile DE programs failed to deliver on promises of game-changing capabilities.
These failures have increased the U.S. military’s reluctance to adopt a
new generation of DE weapons concepts that are based on significantly more mature
technology. Other barriers include institutional desires for “perfect” technological
solutions and insufficient DE program funding. The latter problem may
not soon improve, considering downward pressures on the defense budget.
This report suggests that cultural factors and the lack of resources, not technology
maturity, are now the most significant barriers to developing major new
DE capabilities over the next decade. While developing and fielding these capabilities
will require up-front investments, they have the potential to reduce DoD’s
dependence on costly kinetic weapons that require extensive logistics networks
to replenish, yielding savings that could be used for other priorities. DE capabilities
should therefore be a key part of developing a future capability portfolio
aligned with DoD’s objectives of creating “a smaller, lighter, more agile, flexible
joint force that has to conduct a full range of military activities” while ensuring
that U.S. forces “always maintain a technological edge” over its future enemies.3
To help overcome barriers to developing new DE weapons, it may be useful
to acknowledge that directed-energy capabilities alone will be insufficient to
counter the challenges posed by enemies possessing advanced precision-guided
weapons. Rather, DE technologies can lead to new applications that could,
in combination with kinetic capabilities, enable new operational concepts that
are designed to counter emerging A2/AD networks. In other words, DE capabilities
are not an existential threat to the U.S. military’s kinetic weapons programs
and, in fact, would complement and increase the effectiveness of these systems to
create more robust layered defenses. Ultimately, however, it could take a significant
“win”—the successful transition of a major new high-power DE weapon system
to operational status—to prove the value of this technology to Service leaders
and Combatant Commanders. DE weapons, like many innovative military technologies
that preceded them, may have to be proven in combat before DoD grasps
their full potential.
This report concludes by recommending five initiatives that could be part of
an acquisition plan that focuses DoD investments on the most promising DE initiatives.
It also recommends that such a plan should consider the maturity of DE
technologies and their supporting requirements, including space, power, and cooling
needs, that would affect their integration with operational military platforms.
>> DoD should support the U.S. Navy as the “first adopter” for weaponizing an
SSL capable of producing 100 kilowatts or more of output energy. Surface
ships with sufficient power, volume, and cooling capacity are particularly
well-suited as platforms for SSLs that could become part of a layered defense
against unmanned aerial vehicles (UAVs), anti-ship cruise missiles (ASCMs),
and fast attack craft.
>> The U.S. Army and Air Force should leverage mature laser technologies to develop
deployable, ground-based DE defenses against air and missile threats
to bases in the Western Pacific and Southwest Asia. Combined with kinetic
defenses, a network of DE weapons could shift the cost-imposition calculus in
favor of U.S. power-projection forces. The U.S. Marine Corps should leverage
Navy and Army high-energy laser and SSL development programs to accelerate
fielding of a Ground-Based Air Defense System.
>> The U.S. Air Force and U.S. Navy should lead DoD’s efforts to develop new
HPM weapons that could be integrated into manned and unmanned aircraft,
cruise missiles, and ground vehicles. Unlike state-of-the-art SSLs, HPM weapons
appear to be sufficiently mature and compact to be weaponized in the near
term into packages that could be carried by air platforms. The Air Force and
Navy should continue to pursue technologies that could increase HPM power
outputs and ranges, as well as concepts that could lead to recoverable and reusable
HPM systems capable of attacking scores of targets per sortie.
>> The military Services should work with the Commandant of the U.S. Marine
Corps, DoD’s executive agent for non-lethal weapons, to transition advanced,
non-lethal DE concepts being developed by the Joint Non-Lethal Weapons
Directorate to programs of record. A more concerted, defense-wide effort is
needed to improve Combatant Commanders’ understanding of the potential
for non-lethal DE capabilities to support a wide range of operations.
>> Additional lethality testing to determine the effects of SSL and HPM systems
against various classes of air and ground threats in operationally relevant environments
could inform future DE requirements and investment decisions.
Testing in the near term should seek to develop better data on DE lethality
against vehicles, small boats, UAVs, cruise and ballistic missiles, as well as the
impact of aerosols, humidity, and obscurants on laser weapons operating in
maritime and ground battlefield environments.
.
When a new technology appears in business or war, advantages in cost or efficiency—
albeit initially marginal—may be clear almost from its appearance. Conversely, decades
or even centuries may pass before we conclude that the new technology is not a
substitute for the old but offers the opportunity to move into a new dimension previously
not available or even conceived. Such myopia often leads otherwise competent
observers to underestimate significantly the new technology’s potential.
—Colonel John A. Warden III
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Today, the United States retains an unparalleled ability to project conventional
military power abroad. This ability is eroding swiftly, however, as state and
non-state actors pursue asymmetric approaches to offset America’s military
strengths in the air, on land, at sea, and in space and cyberspace. The continuing
proliferation of advanced military technologies, such as ASCMs, ballistic missiles,
and integrated air defense systems (IADS), are underpinning the development
of battle networks that guard the approaches to the Western Pacific, Persian
Gulf, and other regions of vital interest to the United States. Moreover, many of
these A2/AD threats, particularly precision-guided cruise and ballistic missiles,
are on balance less expensive and easier to replace than the kinetic systems the
U.S. military uses to defend against them.5 This could allow an enemy to impose
costs on U.S. forces.
In lieu of simply “buying more of the same” in response to these challenges,
DoD should invest in new military technologies that can shift this unfavorable
cost-exchange ratio in favor of the United States. The imperative to pursue such
a course is particularly strong in an age of declining defense budgets such as the
one in which the United States finds itself today. This report focuses on future offensive
and defensive DE capabilities that have the potential to create new operational
advantages for the U.S. military. Combined with kinetic weapons, future
DE weapon systems could help the United States buy back its ability to project
military power at acceptable levels of risk and cost.
As with any major evolution in military technologies, there are barriers
that must be overcome before significant new DE capabilities can be fielded.
Technological challenges include the need to reduce the volume, weight, power,
and cooling requirements of high-energy SSLs to levels that allow them to be integrated
into aircraft and ground vehicles. DoD must also overcome institutional
obstacles that hinder the transition of DE technologies to full-scale programs of
record. Leaders in the Office of the Secretary of Defense, Service Departments,
and Combatant Commands need to recognize the potential of emerging DE technologies
and champion their development through DoD’s myriad requirements,
acquisition, and budgeting processes.
approach
This assessment has two primary objectives: (1) to examine the potential of new
DE capabilities to enable a breakout from an emerging operational stalemate and
shift cost-exchange ratios in favor of the U.S. military; and (2) to identify DE technologies
that have the greatest promise to transition into the Pentagon’s program
of record over the next ten to twenty years.
Toward this end, Chapter One begins by summarizing the characteristics of
a mature precision-guided weapons regime and its potential impact on future
U.S. operations. Chapter Two continues by assessing the unique attributes of
high-energy DE systems that could confer significant advantages on U.S. forces
and help DoD move toward a favorable cost-benefit ratio against adversaries with
capable A2/AD battle networks. Chapter Three evaluates a variety of promising
DE concepts that could be transitioned to full-scale weapons programs. Chapter
Four postulates how a number of these DE applications could be used to support
future operations against A2/AD battle networks emerging in the Western Pacific
and Persian Gulf. Chapter Five summarizes key technological, institutional, and
resource challenges that must be overcome if the U.S. military is to field these
new, potentially game-changing DE capabilities. The paper concludes by recommending
elements of a weapons development program that focuses on transitioning
the most promising DE technologies to operational systems.
A distinctive “American way of war” has evolved over the last sixty years, first
to meet the Soviet threat during the Cold War and then to project forces abroad
to support regional contingency operations. A number of attributes have come
to characterize this way of war. Military assets that underpin major U.S. operations
typically consist of large, high-signature formations such as carrier strike
groups (CSGs), squadrons of aircraft, and brigade combat teams. Deploying and
sustaining these formations in distant theaters has led to the development of sophisticated
logistics networks. Once deployed, U.S. forces rely on large theater
bases that act as secure staging areas for combat and combat support operations.
Tying all of these elements together is an extensive information infrastructure
that gathers and shares intelligence, provides accurate navigation and targeting
data, and coordinates complex operations over extended distances.
In the past, this way of war has been described as massing destructive combat
power to wage campaigns of attrition against an enemy’s military forces.6 With
the advent of advanced guided weapons, the Industrial Age concept of massing
fires to conduct wars of attrition has largely been supplanted by the ability to create
precise effects on specific targets. Since the end of the Cold War, the U.S. military
has assumed that its sophisticated reconnaissance-strike complex (RSC),
composed of advanced sensors, precision-guided weapons, and information networks,
would not be matched by regional military powers.7 This assumption appeared
to have been validated during operations in which U.S. forces dominated
the skies over Kosovo, twice made short work of Saddam Hussein’s military, and
quickly knocked the Taliban out of power in Afghanistan.8
These successes did not occur in a closed system, however. Potential adversaries
have observed the effectiveness of America’s RSC and are developing
capabilities to counter it in all operating domains. Thus, it is important to understand
how potential opponents are adapting and why these adaptations are
invalidating America’s traditional power-projection assumptions.9 Accordingly,
the following sections briefly summarize the general characteristics of a maturing
precision-guided weapons regime and its potential impact on future U.S.
power-projection operations.
china ’s a2/ad reconnaisance -
stri ke comp lex
Although projecting military force overseas has always been a challenging and
costly endeavor for the United States, the proliferation of competing RSCs is
likely to make future U.S. operations far more difficult. The People’s Republic of
China (PRC), for example, is developing a sophisticated RSC to guard its eastern
air and maritime approaches. This RSC, which is actually a network of networks,
includes a variety of counter-air, counter-space, and counter-network capabilities
as well as extended-range precision strike weapons and surveillance systems
to support over-the-horizon attacks against targets at sea and on land.
China has designed its RSC to target key dependencies underpinning U.S.
military operations. After watching the fate that befell Saddam Hussein, who allowed
the United States and its coalition partners to mass a decisive force along
Iraq’s borders in 1991 and 2003, China designed an A2/AD strategy to exploit the
U.S. military’s dependence on a small number of main operating bases located
in the Western Pacific.10 As part of this strategy, China apparently plans to target
these bases as well as the extended air and sea lines of communication that are
essential to sustaining U.S. power-projection operations. China also appears to
be preparing to supplement these actions by launching kinetic and non-kinetic
attacks against surveillance and long-haul communications battle networks to
render deployed U.S. forces nearly deaf, mute, and blind.11 Against such challenges,
it is not clear that the U.S. military could execute its traditional post-Cold
War concepts of operation effectively, or do so at acceptable levels of risk.12
iran ’s emerging a2/ad strategy
In many ways, China’s military modernization is a harbinger of a broader trend in
which smaller regional powers and even non-state actors are seeking to develop
or procure similar asymmetric capabilities. Iran, for instance, is pursuing an A2/
AD strategy that leverages the unique geography of the Persian Gulf region to its
advantage. Iran has fielded ASCMs and fast attack craft armed with rockets that
it can use in large numbers to “swarm” U.S. warships operating in the confined
waters of the Strait of Hormuz. Iran’s fleet of conventionally powered submarines,
including several Russian-built Kilo-class boats and a larger number of
“midget” submarines, could attack surface vessels directly or lay mines to channelize
U.S. naval operations.13
Over the last two decades, Iran has also acquired a large inventory of road-mobile,
short-range ballistic missiles and a small but growing number of longer-range missiles.
While these missiles are not as accurate as their Chinese counterparts, Iran
could use them to threaten, coerce, and punish its neighbors, much as it did during
the “War of the Cities” with Iraq in the 1980s.14 In other words, instead of using its
ballistic missiles to attack U.S. forces in the field directly, Iran could employ
them in a campaign intended to compel Persian Gulf states to deny overflight
11 On the PRC’s military modernization and strategy, see Thomas J. Christensen, “Posing Problems
Without Catching Up: China’s Rise and Challenges for U.S. Security Policy,” International
Security, 25, No. 4, Spring 2001; Roger Cliff et al, Entering the Dragon’s Lair: Chinese Antiaccess
Strategies and Their Implications for the United States (Santa Monica, CA: RAND Corporation,
2007); and Randall Schriver and Mark Stokes, Evolving Capabilities of the Chinese People’s
Liberation Army: Consequences of Coercive Aerospace Power for United States Conventional
Deterrence (Washington, DC: Project 2049 Institute, 2008).
12 For a more complete overview of the assumptions underpinning U.S. military operational concepts
for projecting power since the end of the Cold War, see van Tol et al, AirSea Battle, pp. 50-52;
and Gunzinger, Outside-In, pp. 14-18.
13 Iran’s Naval Forces: From Guerrilla Warfare to Modern Naval Strategy (Washington, DC: Office
of Naval Intelligence, 2009), pp. 13, 17-18; Steven R. Ward, “The Continuing Evolution of Iran’s
Military Doctrine,” Middle East Journal, 59, No. 4, Autumn 2005, pp. 568-569; and David Eshel,
“David and Goliath,” Aviation Week and Space Technology, March 28, 2010.
14 For a summary of Iran’s missile capabilities, see National Air and Space Intelligence Center,
Ballistic and
access and bases to U.S. forces, thus undercutting the United States’ ability to
project power into the region.
non-state actors
The low cost of many guided weapons, combined with their potential to terrorize
local populations, may make them a weapon of choice for non-state actors such
as irregular terrorist groups. During the July 2006 conflict in southern Lebanon,
Hezbollah fighters trained and equipped by Iran and Syria used large numbers
of unguided weapons combined with a handful of guided munitions, such
as anti-tank guided missiles (ATGMs) and a C-802 ASCM, against Israeli forces.
15 Hezbollah has since improved its strike capabilities by acquiring additional
ASCMs and advanced man-portable air defense systems (MANPADS). Hezbollah
may also possess solid-fueled M-600 surface-to-surface missiles, a version of
Iran’s Fateh-110 missile, which have a range of nearly 110 nautical miles (nm).16
Given this continuing “proliferation of precision” and the diffusion of other
advanced military technologies to state and non-state actors, the day may be fast
approaching when the U.S. military will no longer be able to operate from forward
sanctuaries and use its superior RSC to overwhelm its opponents. Deep
magazines of guided munitions and the ability to exploit internal lines of operation
may confer significant advantages to forces opposing a U.S. military that
remains dependent on a small number of theater bases, extended lines of communication,
and capabilities that are increasingly expensive to develop, procure,
maintain, and deploy.
imp lications for u.s. mi litary operations
One Example: The Missile Salvo Competition
This dynamic is perhaps best illustrated by the “competition” between a deployed
U.S. force and a regional power that is equipped with a large magazine of precision-
guided ballistic missiles. In the event of a conflict with China, for example,
the People’s Liberation Army (PLA) 2nd Artillery Corps could launch multiple
ballistic missile salvo attacks to overwhelm the limited kinetic missile defenses of
U.S. bases in Japan and Guam. These attacks may be far too large to counter effectively
or affordably with kinetic interceptors or by other traditional measures,
such as hardening base facilities.17 Similarly, Iran is fielding a large number of
short- and medium-range ballistic missiles that can reach target areas across the
Middle East, some variants of which may be capable of carrying chemical, biological,
or nuclear warheads.
Assuming DoD’s program of record does not change, countering missile salvos
launched by the PLA, Iran, or another regional power will depend on the effective use
of kinetic defenses such as $3.3 million Patriot Advanced Capability-3 (PAC-3) missiles,
$9 million Terminal High Altitude Area Defense (THAAD) missiles, and
$10-15 million Standard Missile-3s (SM-3).18 At these prices, defending against
a salvo of thirty ballistic missiles could cost approximately $700 million, assuming
two interceptors are launched at each incoming round in a “shoot-look-shoot”
tactic designed to maximize the probability of a successful intercept.19 This estimate
excludes the cost of repairing damage inflicted by probable missile “leakers”
that successfully elude intercepts.20 Conversely, the enemy’s price for such a
salvo could be approximately 10 to 15 percent of the U.S. military’s cost to defend
against it.21 Thus, while America’s precision RSC has been a foundation for pro-
jecting military power over the last two decades, the maturation of competing
RSCs may lead to situations in which the high cost of defending forward bases
and forces using conventional weapons could greatly hinder U.S. operations.
What are the alternatives for breaking out of this unfavorable dynamic and
regaining the operational initiative? One approach would be to simply counter
the problem symmetrically by acquiring additional kinetic defenses. This would,
however, do nothing to alter the aforementioned unfavorable cost-exchange ratio.
Another alternative might be to further harden and disperse U.S. military
bases located in critical regions. While diversifying and increasing the resiliency
of the U.S. military’s forward posture is desirable, it could be costly
and might require new host nation agreements in politically sensitive areas.
Furthermore, enemies with adequate resources could offset such an approach
by expanding their missile arsenals and developing penetrating warheads.
There are less resource-intensive, asymmetric approaches that could help
shift the cost-exchange ratio in favor of U.S. forces. For example, the U.S.
military could develop new operational concepts to regain its freedom of action
at strategic distances. Anti-access strategies utilizing extended-range
precision-strike capabilities depend on non-line-of-sight command, control,
and targeting networks. This creates an opportunity for U.S. forces to conduct
operations that “blind” an opposing battle network, thereby reducing the effectiveness
of an enemy’s long-range strikes against mobile targets. Although
still able to attack known, fixed locations such as major airfields and ports,
without an accurate picture of the extended battlespace an enemy could neither
assess the effectiveness of its strikes nor confirm the presence of U.S.
forces at targeted locations. This could induce an opposing force to waste its
ballistic and cruise missiles by conducting unnecessary restrikes or expending
ordnance against targets with negligible military value.
Another option would be to employ novel operational concepts enabled by
new technologies. Fielding directed-energy weapons that could provide nearly
unlimited magazines to counter enemy threats for a negligible cost per shot
would enable new constructs such as AirSea Battle, as assessed in the next
chapter. These weapons could improve the U.S. military’s ability to defend
bases and maneuver units that are within range of an enemy’s strike systems.
Moreover, they could enable land- and sea-based air forces to operate from
staging locations that are closer to an enemy’s homeland, which in turn could
increase the number of offensive strikes that U.S. forces could conduct in a
given period of time. The end result could be a breakout from an operational
stalemate created by capable A2/AD weapons complexes as well as a reversal
of the cost-exchange calculus in favor of the U.S. military.
.
summary
The emergence of competing RSCs may create an operating environment that
“render(s) deploying large forces overseas and sustaining them through ports and
fixed bases, too costly in terms of casualties and equipment attrition,” thereby obviating
the American way of war.22 To break out of this cost-imposing paradigm
and regain the initiative, DoD should adopt innovative operational concepts such
as AirSea Battle and field new military technologies capable of countering an
adversary’s missile magazine in an affordable, asymmetric manner. Since other
Center for Strategic and Budgetary Assessments (CSBA) reports have addressed
the need for DoD to develop new operational concepts and long-range surveillance
and strike capabilities, the remainder of this assessment will focus on DE
technologies that have the potential to support these objectives.
.
Since the end of the Cold War, the U.S. military has become accustomed to deploying
large, technologically superior forces abroad to overwhelm opposing militaries.
Today, the United States is facing the possibility that the widespread proliferation
of precision-guided weapons and other sophisticated technologies will significantly
alter the character of future conflicts. Indeed, the United States may find itself in
situations where deploying military forces could incur excessive risk. Given these
circumstances, the United States should be wary of committing to a defense program
that continues to prioritize military capabilities with flattening or declining
cost-benefit ratios, as noted by Secretary of Defense Robert M. Gates:
When it comes to procurement, for the better part of five decades, the trend has
gone toward lower numbers [of systems] as technology gains have made each
system more capable. In recent years, these platforms have grown ever more
baroque, have become ever more costly, are taking longer to build, and are being
fielded in ever-dwindling quantities. Given that resources are not unlimited,
the dynamic of exchanging numbers for capability is perhaps reaching a point of
diminishing returns.
To reverse this unfavorable trend, DoD should place greater emphasis on new
technologies that would help regain the U.S. military’s freedom of action in future,
non-permissive operating environments. History is replete with examples
of technological innovations that have permitted militaries to shift from one warfare
regime to another. The advent of steam-powered ironclad vessels, the invention
of the machine gun, and the development of motorized armored vehicles are
all well-known examples of technologies that enabled major advances in military effectiveness
once they were incorporated into new forms of military operations. More
recently, the maturation of stealth aircraft and precision-guided weaponry have given
U.S. air forces advantages that have served them well over the last twenty years.
Today, emerging A2/AD battle networks pose new operational challenges for
the U.S. military, challenges for which present solutions, which are based on incrementally
improving current technologies, may be both inadequate and too expensive.
Simply put, as guided munitions such as ASCMs, anti-ship ballistic missiles
(ASBMs), and G-RAMM proliferate, defensive approaches that rely solely on expensive,
one-time-use interceptors are becoming operationally unfeasible and fiscally
unsustainable. The fielding of new technologies that shift this dynamic in favor of
the U.S. military could give it a decisive advantage against America’s future enemies.
Thus, the purpose of this chapter is twofold: to summarize promising DE technologies
and to assess the attributes of DE weapons concepts that could confer significant
advantages to U.S. forces operating in A2/AD environments.
toward a brea kout: emerging
de techno logies
As the extended-range, precision-guided weapons regime matures, it is possible
that dueling RSCs could reach an operational stalemate. In such circumstances,
the United States would have an imperative to field “breakout” capabilities that
could lead to major discontinuities in this competition, thereby retaining the U.S.
military’s freedom of action and enabling power-projection operations.25 After decades
of development, DE technologies have reached sufficient maturity to provide
these capabilities and shift the U.S. military toward a more favorable cost-benefit
curve (see Figure 1)
A Mature DE Arsenal Could Span the Targeting Chain
Although this chapter emphasizes potential high-power DE capabilities, there
is no intent to devalue the utility of low-power DE systems presently fi elded or
in development. A future DE arsenal will likely include a variety of high- and
low-power applications that support military operations across the “fi nd, identify,
fi x, track, target, and engage” targeting chain.
Since the invention of the fi rst laser, DoD has fi elded a variety of low-power
DE devices that have proven their value in combat. Perhaps the most famous
example is the Paveway laser-guided bomb, developed by the Air Force to
strike ground targets in Vietnam with precision.27 During 1972 and 1973, 48
percent of all Paveways dropped around Hanoi and Haiphong achieved direct
hits, compared to a little over 5 percent of unguided bombs that struck their intended
targets in the same area a few years earlier.28 By the end of the Vietnam
confl ict, the Air Force alone had dropped more than 25,000 laser-guided
weapons.29 In more recent years, low-power lasers have been used in a variety
of applications, including systems that counter infrared sensors on MANPADS
and hand-held, non-lethal systems that “dazzle” personnel who pose a potential
threat to ground forces. In the near future, other low-power capabilities
could include laser-based networks that provide secure communications for
military forces penetrating into non-permissive areas.
While low-power DE applications have proven themselves for more than
forty years, maturing technologies for high-power systems could give U.S.
forces new advantages that span the entire targeting chain (see Figure 2).30 For example,
high-power microwave weapons could be used to target and degrade or destroy
the electronic components of A2/AD battle networks. New high-energy laser
technologies are also on the cusp of powering game-changing weapon systems that
could defend forward bases and forces against aircraft, ballistic missiles, cruise missiles,
and G-RAMM.
High-Energy Lasers (HELs)
In contrast to light bulbs that emit “white light” (photons with a multitude of different
wavelengths and phases in all directions), lasers produce narrow beams of
monochromatic (single-wavelength) light in coherent beams (all photons traveling
in the same direction with the same phase). These narrow beams can focus
energy precisely on a designated point. There are three primary types of HELs:
chemical lasers, also known as gas dynamic lasers; solid-state lasers; and free
electron lasers. Beyond differences in the lasing media, each type has fundamental
attributes that affect their ability to mature into operational weapon systems.31
In addition to the actual lasers, target tracking, laser pointing, thermal management,
and beam control systems are required to place as much laser energy as
possible on a target over operationally relevant distances.32
Chemical Lasers
Chemical lasers are the only current DE systems able to achieve the power needed
to interdict targets such as ballistic missiles over hundreds of kilometers. As a
result, chemical lasers have until recently been the basis for DoD’s most mature
HEL concepts.
Chemical lasers use exothermic (energy-liberating) reactions of various chemicals
in the gas phase to create atoms or ions in excited states within a lasing
medium. Since these reactions must occur at very low pressures—typically only
a couple percent of atmospheric pressure—chemical lasers are large devices requiring
vacuum pumps, complex chemical management systems, and low-pressure
reaction chambers contained inside a laser resonator.
While there are several types of chemical lasers, DoD used chemical oxygen-iodine
lasers (COIL) for the Airborne Laser (ABL) and Boeing’s Advanced Tactical Laser
(ATL) developmental programs.33 COILs are capable of generating megawatt-class
beams at high efficiencies with good beam quality. The ABL was designed to use a
COIL-based weapon system capable of generating the megawatts of power needed
to reach across hundreds of kilometers to destroy ballistic missiles in their boost
phase of flight, and to do so in a few seconds. Each of the ABL’s six lasing modules
was the size of a large sport-utility vehicle and weighed more than two tons. The
complete laser system weighed more than ninety tons, necessitating the use of
one of the largest aircraft in the world, the Boeing 747-400F, to carry it. The developmental
ATL used a smaller COIL mounted in a C-130 aircraft to evaluate the
potential of an airborne HEL to conduct tactical strikes against stationary and
moving ground targets. Although the ATL’s COIL energy output was less than
5 percent of that projected for the ABL, it occupied more than two thirds of a
C-130’s cargo area.
A third developmental chemical laser system—the now-cancelled Tactical
High Energy Laser (THEL)—used a deuterium fluoride (DF) chemical laser.
While the THEL destroyed more than fifty in-flight rockets, artillery, and mortar
rounds during tests, the prototype system occupied five large shipping containers
on a 10,000-square-foot pad.34
Although DoD has spent billions of dollars on prototype chemical lasers, their
large volume, weight, and finite chemical magazines limit the near-term potential
to mount them on mobile platforms such as aircraft and ground vehicles. For
instance, an aircraft equipped with a COIL would have to land to reload after expending
the chemical “fuel” used to create a laser beam. Moreover, since targets
located at greater distances require longer laser dwell times (and hence require
the laser to use more chemical fuel), shots available per sortie would decrease significantly
the further the aircraft was required to stand off from its target area.
Finally, the strict purity requirements and highly toxic and corrosive natures of
chemical laser fuels would necessitate the deployment of a sophisticated logistics
infrastructure to sustain operations at forward locations.
The U.S. Air Force has made great progress toward improving the power
and efficiency of COIL modules while reducing their overall size, weight, and
supporting logistics needs. With adequate support and resources, this effort
could lead to a new generation of lasers that are suitable to defend forward bases,
critical fixed infrastructure, and regional chokepoints such as the Strait of
Hormuz against a range of threats (see Chapter 3).
Solid-State Lasers
The first laser invented in 1960 was an SSL. Today, low-power SSLs with outputs
of milliwatts are used in a wide variety of consumer products, such as DVD
players and laser jet printers. Watt-class SSLs are used in numerous military applications,
including target range finders (laser radars, also known as ladars),
imagers, target designators, and DoD’s Large Aircraft Infrared Countermeasure
(LAIRCM) defensive system (see Figure 3).35
SSLs use ceramic or glass-like solids, rather than a gas, as their lasing media.
There are three SSL types based on the shape of their lasing media: bulk
lasers, which use thick doped slabs of lasing media; fiber lasers, which use single
or multiple strands of doped lasing fibers that look like common optical fibers;
and thin-disk lasers, which use glass-like doped disks about the size of a dime.36
Unlike chemical lasers, SSLs do not need expendable chemical fuels and can use
nearly any source of electrical power, including batteries, aircraft generators,
and ship power plants, to create beams of laser light.37 The outputs of individual
SSLs can be combined to generate a single, higher-output laser beam.
Solid-State Slab Lasers. The first high-energy SSLs used bulk lasing media. While
early bulk SSLs had very low “wall-plug” power efficiencies, newer bulk SSLs are
showing significant promise.38 For example, bulk SSLs developed by the Joint
High Power Solid-State Laser (JHPSSL) program led by DoD’s High Energy
Laser Joint Technology Office demonstrated outputs of over 100 kilowatts
and wall-plug efficiencies of up to 19 percent with long run times. The Defense
Advanced Research Projects Agency (DARPA) is pursuing a developmental SSL
called the High Energy Liquid Laser Air Defense System (HELLADS):
The goal of the HELLADS program is to develop a 150 kilowatt (kW) laser weapon
system that is ten times smaller and lighter than current lasers of similar power, enabling
integration onto tactical aircraft to defend against and defeat ground threats.
With a weight goal of less than five kilograms per kilowatt, and volume of three cubic
meters for the laser system, HELLADS seeks to enable high-energy lasers to be
integrated onto tactical aircraft, significantly increasing engagement ranges compared
to ground-based systems.39
Fiber Lasers. Similar to slab lasers, it is possible to combine the outputs of single
fiber lasers to achieve higher power outputs. Single fiber lasers have achieved a
maximum output of a few kilowatts.40 A Raytheon-Sandia National Laboratory test
conducted in June 2006 used an off-the-shelf 20-kilowatt commercial welding laser
with very poor beam quality that combined the outputs of many fi ber lasers to
detonate a stationary 62 millimeter mortar round at 500 meters.41 It is possible that
future systems with multiple fi ber lasers could achieve power outputs in the hundreds
of kilowatts. Several ongoing DoD and industry research and development
efforts are focused on coherently combining the outputs of fi ber lasers.
thin-Disk Lasers. Thin-disk laser systems have produced up to 3.4 kilowatts using
four disk lasers in a single resonator. Although this class of SSLs promises a
signifi cant reduction in laser weight compared to chemical lasers, thin-disk lasers
typically require far more optical components (see Figure 4) and are thus
more complex.
Free Electron lasers (FEls)
Free electron laser (FEL) systems accelerate beams of electrons to nearly the
speed of light in racetrack-like accelerator rings and use powerful magnets to
“wiggle” the electron beams to generate high-energy beams of laser photons.
FELs are of interest to the Navy due to their potential to achieve the high power
outputs needed to interdict hardened targets such as incoming ballistic missile
reentry vehicles, and their unique ability to “tune” their beams to different
wavelengths to different wavelengths so they can better transmit through the
dense, humid atmospheres of maritime environments.42
Current developmental FELs are extremely large and inefficient. A FEL at the
Department of Energy’s Jefferson Laboratory, which has demonstrated an output
of 17 kilowatts at 1 percent efficiency, is nearly 240 feet long and 40 feet wide. Over
time, it is likely that the overall size of FELs will decrease as technologies for their
electron sources and accelerators mature.43 The U.S. Navy is interested in developing
technologies that could lead to a FEL with megawatt-class output levels in the
2020s.44 Multi-megawatt-class FELs may eventually achieve wall-plug efficiencies
of 5 to 10 percent. While better than today’s FELs, these systems would still present
considerable challenges in terms of the thermal loads placed on ship systems and
the shielding required to protect ship systems and personnel.
High-Power Microwave Weapons
A high-power microwave weapon uses electricity to power a microwave generator
that emits very short pulses—typically nanoseconds to microseconds in
duration—of microwave radiation at megawatt to gigawatt output levels. Future
HPM weapons could emit beams of radiation that are a few degrees wide to
attack targets in specific locations or emit radiation multi-directionally to degrade
electronic components over wider areas. The effects created by HPM applications
could range from temporarily disrupting electronic systems such as
computers to physically burning out systems that are not shielded against the
high electromagnetic fi elds generated by an HPM pulse.45 Since HPM beams
cannot be as tightly focused as lasers, the energy per unit area in HPM beams
decreases signifi cantly over distance. This could impose signifi cant operational
limitations compared to longer-range laser weapons (see Figure 5).46
Since HPM weapons would affect all unshielded electronic systems within
their beam spots, care must be taken when employing them to avoid collateral
damage to nearby friendly systems.
.
Non-Lethal Directed-Energy Weapons
Non-lethal directed-energy capabilities have been proven to be safe, legal, and
treaty-compliant means of supporting area denial, crowd dispersal, static security,
and other related missions. DoD’s Joint Non-Lethal Weapons Program is pursuing
promising DE technologies to complement the kinetic non-lethal weapons inventory.
47 Non-lethal anti-personnel DE systems, such as optical disruptors (dazzling lasers)
and acoustic hailing devices, are currently available to warfighters. Promising
new non-lethal capabilities include the Active Denial System (ADS), which uses a
focused millimeter-wave beam to create a “push, shove, or repel” effect through a
harmless heating of the surface of a person’s skin. Research is also underway on the
potential to use radio frequency energy to stop ground vehicles and small vessels
without lethal effects to their operators and passengers.
unique attrib utes of directed -
energy weapons
The attributes of DE technologies make them promising candidates to “jump the
curve” and provide the U.S. military with new advantages over capable enemies
during future power-projection operations.
Creating Advantage s in Time
All DE applications transmit electromagnetic radiation in the form of photons that
travel at the speed of light.48 Thus, when an operator fires a DE system, the energy
needed to create a desired effect can reach a target almost instantaneously. For example,
a high-energy laser weapon integrated with a ship’s anti-air warfare defensive
systems could engage an incoming cruise missile while it is kilometers away in less
than a millisecond and maintain its focus on the missile to destroy or disable it within
a few seconds. This engagement speed would make it possible for a single DE defensive
system to engage several incoming aircraft, missiles, mortar shells, or artillery
rounds in a very short period of time to protect ships, forward operating locations,
and troops in the field. Such a capability would be particularly valuable against adversaries
employing salvo attacks of ASCMs or G-RAMM to saturate U.S. defenses.
Moreover, high-power DE systems could conceivably defeat multiple air and missile
threats before an enemy could employ countermeasures to avoid an intercept.
Creating Advantage s in Magazine Depth
The magazines of electric DE weapon systems could be nearly infinite compared
to the number of kinetic munitions that are typically carried by U.S. military aircraft,
ships, and ground vehicles. This has significant operational implications.
>> Electric-powered DE weapons could increase the mission duration of
air-refuelable aircraft that currently carry expendable air-to-air and air-tosurface
munitions. Similarly, DE weapons could increase the time-on-station of
deployed naval vessels, since their “magazines” would not require periodic replenishment
at a port facility.
>> While it is probable that DE defenses—much like kinetic defenses—could be
overwhelmed by ballistic missile salvo attacks, a combination of DE and kinetic
systems could increase the number of defensive engagements per salvo
attack and thus reduce the potential for enemy missile “leakers” to hit their
targets.
>> Although surface-to-air and air-to-air munitions will be critical to future
U.S. air and missile defense architectures, operational DE weapons with
nearly infinite magazines could reduce requirements for mobile weapon systems
to carry defensive kinetic munitions. This would enable large combatants,
such as naval vessels, to carry additional offensive capabilities.
The firing rates of future electric laser weapon systems will be contingent on their
ability to dissipate the waste heat generated during the production of a high-energy
laser beam.50 For HPM weapons installed in aircraft or cruise missiles, the amount
of energy provided by batteries, not waste heat elimination, will determine the
number of shots and rate of fire. Because these batteries could be recharged in
flight, HPM weapons could have magazines limited only by the endurance of the
platforms that carry them.
Creating Favorable Cost-Exchange Ratios
The recurring cost per shot of DE weapons can be measured by the cost of generating
the electricity needed to create their beams. In the case of electric lasers and
HPM weapons, this will likely be tens of dollars per shot, far less than the price of
a PAC-3 missile or similar interceptor.51 This could reduce the cost of defending
against incoming salvos of ballistic and cruise missiles by orders of magnitude.
DE weapons could therefore provide the U.S. military with a significant advantage
over enemies who remain dependent on more expensive long-range missiles.
Creating Non-Lethal Effects
One additional attribute of DE capabilities deserves mention. Future laser weapons
could be very precisely focused to permit U.S. troops to engage targets surgically,
even in very close proximity to friendly forces or noncombatants. Although
HPM beams cannot be focused as precisely as lasers, their potential to counter
the electronics of an adversary’s weapon systems and infrastructure without
harming humans could greatly increase options available to future commanders.
summary
Innovative technologies have the potential to create significant operational advantages
for militaries that are willing and able to exploit them. The unique attributes
of future DE capabilities—including their ability to produce precise and
tailored effects against multiple targets, their “speed-of-light” responsiveness,
and their deep magazines—could allow them to support a wide range of missions
and create new opportunities for the U.S. military to gain a disruptive advantage
in the emerging precision-guided weapons regime. Simply stated, future DE
capabilities could lead to a new military technology “breakout.” Moreover, their
much lower cost per shot compared to expendable kinetic munitions could help
reestablish a cost-imposition dynamic that is favorable to U.S. forces. From a resource
perspective, a future DE-enabled U.S. military could reduce its overall
requirements to procure, deploy, store, and maintain large inventories of conventional
weapons such as ballistic missile interceptors, thus freeing DoD funds for
other priority investments.
The next two chapters further assess prospective DE applications and their potential
to help create the freedom of action U.S. forces would need during operations
against capable A2/AD complexes in Southwest Asia and the Western Pacific.
The U.S. military has long sought to capitalize on the promise of directed energy.
Since the invention of the laser in 1960, DoD has invested more than $6 billion
in DE S&T initiatives.52 While numerous low-energy DE applications have transitioned
to programs of record over the last fifty years, only a few high-energy concepts,
including the ABL, THEL, and ADS, have made the leap over the “valley
of death” between laboratory demonstration systems and working prototypes.53
Moreover, none of the high-energy concepts that made this leap have become
fully operational weapon systems.
Today, high-energy laser, HPM, and non-lethal technologies have advanced
to the point where DoD could develop and field DE capabilities that promise to
“transform warfighting, enabling revolutionary advances in engagement precision,
lethality, speed of attack, and range.”54 This chapter identifies DE concepts
that may have the most promise to transition from the laboratory to the battlefield
over the next two decades. The concepts proposed in this chapter are based
on the maturity of the requisite technologies, not current Service programs.
the ne xt fi ve to ten years
This section describes ongoing and potential technology development efforts that
could lead to the fielding of DE applications in the next five to ten years. Although
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DoD is currently funding a number of these initiatives, it is possible that many,
if not most, will remain at the conceptual level or will be terminated after their
initial demonstrations due to the lack of resources and support by the Combatant
Commands and Services.
Ship-Based Solid-State Lasers
The Navy has funded two significant high-power SSL technology initiatives, the
Laser Weapon System (LaWS) and Maritime Laser Demonstrator (MLD), which
could lead to new capabilities to counter UAVs, fast attack craft, and potentially
ASCMs. LaWS combined six commercial SSLs with a beam director mounted
on a Phalanx gun system to produce a 32-kilowatt beam of laser energy. The
LaWS demonstrator shot down four UAVs flying over water close to California’s
San Nicolas Island in 2010.55 The Office of Naval Research funded development
of a second high-power SSL, the MLD, to counter small boats, UAVs and other
threats to surface ships.
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