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In a sense, the Tomahawk cruise missile, here erupting from an armored box launcher on the deck of the destroyer Merrill (DD-976), is a small, pilotless aircraft. It is capable of traveling long distance, navigating by on-board equipment, and delivering its payload—much as an attack airplane would. Thus, it has the potential for transforming dozens of surface combatants and submarines into offensive strike platforms. Although plagued by difficulties in the past, the weapon system now appears on track and during 1983 made its first deployment on board the battleship New Jersey (BB-62).
For the future, more remains to be done, including development of the nuclear land-attack version. At present, U. S. Navy ships are armed only with the conventional variety. Also on the agenda is the business of developing doctrine and tactics for Tomahawk. Such development will require imagination, testing, and practice—finding the right combination of weapons, sensors, targeting, and objectives.
Tomahawk
By Commander Miles A. Libbey III, U. S. Naval Reserve
For more than a generation, the U. S. Navy has been built around the striking power embodied in tactical aircraft and the ships which support them. Today, the aircraft carrier and her planes are in the process of gaining a potent new partner in the means of fulfilling the Navy’s mission. The versatile Tomahawk cruise missile offers a leap forward in both offensive and defensive power.
Offensively, the new-generation cruise missile can attack land and ship targets from hundreds of miles away. By offering about twice the range of an unrefueled manned aircraft, the land-attack Tomahawk can hold a significant portion of the Soviet Union at risk. By standing far at sea, a ship armed with Tomahawk can neutralize important targets ashore, such as naval bases and airfields, or soften them in preparation for attack by manned aircraft. Defensively, since a Tomahawk-armed ship is so threatening to the Soviet Union, launch ships themselves become important targets and thus dilute decades of Soviet planning efforts against American aircraft carriers and their formations. Before dealing with the tactical and strategic implications of this new weapon, however, let us examine the missile itself and its predecessors in order to put Tomahawk in perspective.
Characteristics
A smart, air-breathing, far-reaching 20-foot winged torpedo conjures up just about the right image. Only in the last decade have cruise missiles become practical as the result of technology maturing in several key fields: computer miniaturization; small, efficient turbofan engines; and ground-hugging guidance systems. There is a price for all this, of course; each Tomahawk costs over $2.5 million a copy. Yet, the tactical advantage of striking an enemy from hundreds of miles away with an accuracy of a few yards is a worthwhile goal. Closely related to drones and remotely piloted vehicles (RPVs), cruise missiles are fundamentally different from their intercontinental ballistic missile (ICBM) cousins in several respects. First, rather than following a path dictated by gravity through sub-orbital space, Tomahawk “cruises” or flies aerodynamically like a pre-programmed pilotless airplane. Second, a sophisticated guidance system and a high technology terminal system steer the missile to within yards of a target, far more accurately than ballistic trajectories. Third, Tomahawk is powered by a small air-breathing engine rather than huge rockets that lift ICBMs above the atmosphere. Size (Tomahawk is much smaller), speed (slower), and range (less) also differentiate Tomahawk from an ICBM. Tomahawk’s general characteristics are shown in Table 1.
Commander Miles A. Libbey III is a 1967 graduate of the Naval Academy who served in several destroyers and had a tour as aide and flag lieutenant to Commander Sixth Fleet. He was executive officer of the USS Spruance (DD-963) and commanding officer of the USS Nicholson (DD-982). He spent one year as a CNO fellow and had two tours of service on the board of control and editorial board of the Naval Institute. He earned his Ph.D. from the Fletcher School of Law and Diplomacy as the first Samuel Eliot Morison Scholar in Naval History. Commander Libbey is a frequent contributor to naval and defense publications, including a number of articles for the Proceedings on the subject of tactics. This article was written during a recently completed tour of duty in the office of the Chief of Naval Operations. He has since become a member of the Naval Reserve.
History
In the memoirs he wrote after leaving office as Chief of Naval Operations, Admiral Elmo R. Zumwalt, Jr., opined that . . the Navy’s dropping in the 1950s of a promising program for a cruise missile called ‘Regulus’ was the single worst decision about weapons it made during my years of naval service.”1 Regulus was carried in dry capsules on board submarines and had a range of about 400 miles. The system was deployed on Pacific Fleet submarines until the mid-1960s. Zumwalt blamed what he called the aviators’ union for overemphasizing large-deck aircraft carriers and therefore deciding not to proceed with cruise missile development. In Zumwalt’s Project 60, a strategic assessment of the Navy and a framework for his tenure as CNO, he called for the development and deployment of a “proper” cruise missile—one that would reach well beyond the 60-mile Harpoon.
In September 1971, a Navy project found that a land- attack cruise missile was technologically possible. The Secretary of Defense in mid-1972 ordered a program that would put the cruise missile on nuclear-powered submarines. Six months later, the Defense Systems Acquisition Review Council (DSARC) instructed the Navy to develop a submarine-launched cruise missile. Additionally, the Navy was instructed to coordinate closely with the Air Force and to develop a surface launching capability as well.
Coincidentally, during Zumwalt’s tenure in office, White House national security advisor Henry Kissinger gave the cruise missile project a crucial boost in negotiations for a SALT II treaty, which started in October 1972. In May 1973, Kissinger met with Soviet leader Leonid Brezhnev in an effort to break the stalemated talks. Kissinger used the intriguing ploy of offering up a non-system! More accurately, he offered to limit what was then a nonsystem to a maximum range of 3,000 kilometers, one that many in the Pentagon, aside from Zumwalt, were not en-
thusiastic about building.2 When Kissinger returned to Washington, he added his push for a cruise missile program that would fulfill his bargaining chip requirements.
By January of 1975, the Navy and Air Force were instructed by the office of the Secretary of Defense to adjust their programs to follow parallel tracks and make the most efficient use of common equipment. The DSARC met again in January 1977 and decided that both the antiship and land-attack versions of Tomahawk should proceed to full-scale engineering development in order to allow maximum use of common components and the resulting economies of scale in purchasing those components for the variants. The same decision process instructed the Navy and Air Force to merge their separate project management offices into a joint project with the Department of the Navy as executive agent. Despite the use of commonality, different warheads can dramatically change the mission of Tomahawk, as will be discussed later. The European based Air Force ground-launch cruise missile (GLCM) is a Tomahawk variant which is designed to carry exclusively nuclear warheads.
The Joint Cruise Missiles Project Office (JCMPO) was formed in January 1977 and had as its first director Rear Admiral Walter M. Locke, who had been project manager of the Navy’s Tomahawk since 1974. Such long service in one project is unusual and was made all the more so when he was suddenly replaced in early August 1982 by Rear Admiral Stephen J. Hostettler. Problems highlighted in the test and evaluation program caused the Chief of Naval Material to appoint a rear admiral to head a committee to investigate management procedures in the Tomahawk program. A delay in the initial operational capability (IOC) and problems in quality control contributed to Locke’s replacement. Hostettler has been able to draw on his previ-
Table 1 Tomahawk Characteristics
Length: | 21 feet |
Diameter: | 1 foot, 9 inches |
Weight: | About 3,200 pounds |
Wing span: | 8 feet |
Propulsion: | Air-breathing turbofan engine: solid propellant booster for sea or ground launch. |
Speed: | High subsonic (Mach .5 to .75) |
Altitude: | Sea level—10,000 feet |
Range: | TLAM/N, Tomahawk land attack; nuclear 1,500 nautical miles TLAM/C, Tomahawk land attack; conventional 700 nautical miles TASM, Tomahawk antiship missile 250 nautical miles |
Guidance: | TLAM/C/N inertial; TERrain COntour Matching (TERCOM), Correlation (DSMAC) TASM Strapdown attitude heading reference system; active, passive radar |
Warhead: | Nuclear or conventional high explosive |
Source: McDonnell Douglas Astronautics Company Tomahawk brochure. Roger W. Michelson, Theater Cruise Missiles: Concepts and Considerations (Newport Naval War College Center for Advanced Research, 1979), p. .41. Charles A. Sorrels, U. S. Cruise Missile Programs (New York: McGraw-Hill, 1983) cover fold- out.
0US experience as Director of Surface Combat Systems.3
Admiral Hostettler conducted his program review and found the need for more money and manpower and for adjustment of Tomahawk’s operational availability. As uead of a joint project office, the admiral had to set priori- hes for the differing versions of the cruise missile. In order °f Precedence, the list was the ground-launched cruise Hussile, nuclear land attack, antiship, and conventional land attack.4 The ground-launched version was particularly important because of the 1979 request by NATO that the United States station intermediate range missiles in Europe to counter Soviet SS-20s.
In January 1983, it was announced that the Navy and General Dynamics Convair Tomahawk cruise missile program would be restructured. The appointment of a prime migrating contractor was expected to turn around disappointing test failures, quality control problems, and minimize delays in fleet introduction. Quality control problems
^eem to have been solved by aggressive action on all «mts. General Dynamics formed a “gold team” within I corporation to speed resolution of Tomahawk prob- making timely, highly reliable production more lke*y than under the previous setup.
The bad reviews that Tomahawk received early in 1983 jVere apparently mistakenly dragged out again months ater when toward the end of the summer Senate Armed ervices Committee reports complained about test results
and
cited both the Navy and General Dynamics for “unac-
ccptable performance.” Admiral Hostettler countered this
old
evidence and set the record straight: “You don’t get j*even straight test shots by rolling the dice. You get them y reliable rounds.”5
IX
0ctrine
fight:
Reliable missiles are only part of the operational war-
of the
lng equation. In particular, consider the contribution
antiship version of Tomahawk. A decade ago, the
target selection. Should the U. S. fleet adopt the Soviet tactic of using ships as tattletales or markers to report an opposing force’s position? With such a wide variety of choices available on many of these issues, we must encourage our operational commanders to use flexibility. Doctrine will often unduly narrow choices and give false comfort in standard answers. Our doctrine must encourage well-thought-out and tested alternatives without blunting the U. S. Navy’s most potent weapon: the flexible and innovative minds of our battle force commanders.
Doctrine must be based on a firm technical foundation. Technical considerations such as optimum attack profiles for multi-Tomahawk missions must be derived from ex-
12-mile reach of a 5-inch gun struck the engagement arc in which a U. S. Navy destroyer could reach a foe. The targeting problem was minimal; visual and radar means were enough. Today, with Harpoon reaching 60 miles and antiship Tomahawk capable of striking over four times as far, operational benefits and doctrinal problems are magnified greatly. The ability to hit targets 250 miles away puts a vast burden on over-the-horizon targeting capabilities. The commander must coordinate information from satellites, land-based aircraft, tactical planes and helos, as well as submarines and perhaps drones. Should any of these sources radiate their radars or use other active means, risking divulging their location? Or should potentially less accurate passive or covert means be used? When a ship is pinpointed more than 200 miles away, what are the rules of engagement? What sort of identification should be required? Friendly or neutral shipping could be placed at risk easily unless careful consideration is given to each
tensive testing and modeling. Results must be available to the commander in a form that emphasizes the technical aspects of doctrine yet gives tactical flexibility. Computer assisted tactical planning for the commander is essential with the proliferation of Tomahawk-armed ships in a task force. Doctrine must continue to develop as Tomahawk grows more technically capable.
Technical
In concept, the Regulus of the 1950s and 1960s was a perfectly acceptable cruise missile; today’s smaller, refined computer and engine engineering are the real advances to be found in Tomahawk. These improvements have vastly increased ranges and accuracies, making the cruise missile an impressive step forward and a most exciting “new” weapon system.
Engine design has been a major reason for the interest in the current generation of cruise missiles. Leaving behind the older approach of the less capable turbojet, the scheme to use a small turbofan with an increase in efficiency of about 20% has been effective. The Williams turbofan engine, 3 feet long and 1 foot in diameter, was developed as part of the Air Force’s subsonic cruise armed decoy program. This propulsion method uses a 150-pound engine to produce thrust of from 300 pounds during cruise to 600 pounds if needed. The turbofan is optimized for the subsonic speeds of Tomahawk. Increases in range may come from further developments in engine technology. Until recently there has been little use for small jet engine research and development; however growth in cruise missile applications and tactical use of drones should assure growth in range.6
Range considerations can also be partially controlled by the number of fuel tanks and amount of fuel carried by the missile. Another variable is mission altitude. By allowing Tomahawk to climb and cruise at a relatively high altitude, fuel can be conserved until a lower approach is required during a terminal attack phase. Maneuvers may be necessary to avoid concentrations of enemy defenses or simply to fly over ground that will provide enough differentiation in the terrain to allow TERCOM (terrain contour matching) to establish an accurate navigational fix.
In order for a warhead small enough to be carried on a cruise missile to be effective, the guidance system must be extremely accurate. Against “hard” targets, those which have been heavily reinforced, even nuclear warheads must be precise. Strategic missiles, such as those launched from ballistic missile submarines, rely on systems that sense changes in direction by measuring with great precision minute forces of inertia working on masses called accelerometers. These inertial navigation systems integrate changes with other parameters such as speed to determine a missile’s position.
The guidance system also controls the power applied to the turbofan engine and controls the rates of climbs, dives, turns. Additionally, it calculates missile altitude and carefully controls height of flight to decrease probability of detection. For the warhead to be effective after a missile
travels several thousand miles, inertial guidance systems ■trust be updated several times in mid-flight. Different from a ballistic missile, these fixes are necessary in a cruisc missile because at the relatively slower speeds the 'nertial navigation has a longer time to drift, adding ever greater errors if left uncorrected. By noting trends of errors after fixes are computed, the guidance system compensates for the trend and therefore becomes more accurate after each fix.
New navigational information must come from some external source such as star fixes, radar, optical or infrared imagery. While star fixes are fine for a ballistic missile that travels out of the atmosphere, they are not acceptable f°r a Tomahawk flying a hundred feet above the ground in daylight. Later in the decade, satellite supported global Positioning systems like NavStar may offer sufficient ac- ouracy for navigational fixes. Vulnerability to attack on satellites or ground stations will probably keep external uPdate systems such as Loran or NavStar from being used exclusively. Instead, techniques will be used to sample the ■mmediate environment and compare the results with data stored on board.
fhe land attack versions of Tomahawk employ inertial guidance that is updated by the terrain contour matching system which uses a radar altimeter, barometer, computer, jtud small radar. The radar altimeter transmits a signal and by processing the return and integrating the results with he barometer, determines the profile of the ground below. ' his average height above sea level is broken into discrete digital bits ready for comparison. Meanwhile, an on-board computer will have called up the digital representation of he expected terrain from its memory and the comparison begins. When a real-time match is found between expected and actual positions, the distance and direction off he desired course are measured, and a corrective maneuVer is calculated and applied to regain the desired flight Path. At the same time the drift of the inertial guidance Astern is calculated and by biasing the correction subsequent errors are reduced.7
Since even reliable inertial navigation systems can be expected to drift as much as a mile in an hour, updates are Crucial on these relatively slow weapons. Additionally, j^nds will push the missile off the intended path. Boosted r°m an armored box launcher or a vertical launcher sys- e,r>, Tomahawk does not have to be pointed at an intended arget. Tomahawk can also be launched from the torpedo . es of nuclear-powered attack submarines. Firing orders 'V'h be received through normal tactical channels, includes special procedures if nuclear weapons are involved. (. °re booster ignition the ship’s fire control system ini- lahzes the missile with present position and sets the gyro- ?c°Pes in the inertial navigation system. After boosted unch at sea, a missile deploys its aerodynamic wing sur- Ces rapidly, reaching high subsonic cruise speeds and Possibly climbing to altitude to conserve fuel. Guided by s 'nertial navigation system, it heads toward an enemy °astline. After travelling over the water and making land- "• it performs its first update. The radar altimeter mea- fes precisely the terrain below the flight path of the mis- e- Since inaccuracies because of drift and winds will have accumulated during over-water flight, the first map recalled from the computer’s memory has to be wide enough to allow a sufficient comparison to capture the guidance system. Subsequent update maps can be smaller because there will be less time between revisions. Each of these navigational fixes causes a maneuver to put the missile back on the planned route to the target. Between fixes determined by using internally stored maps, the missile can be programmed to fly a path that will avoid concentrations of air defenses, take extra time to coordinate an attack with other missiles or take advantage of more definitive geographical features for guidance.
Thousands of potential targets with several intermediate update stations or waypoints mean that millions of individual data points must be collected and stored in a retrievable fashion to program a strike package for a target. Some of the command and control aspects will be covered later. Stereographic photographs taken from high altitude provide the data base for terrain profiles that are stored in the missile as maps. The maps themselves are a significant consideration. The Defense Mapping Agency is responsible for their preparation, a project that is estimated to cost about a billion dollars. Other missiles, such as Pershing II, will share the cost and benefits of DMA’s efforts.
There are four general types of terrain contour matching maps which are used, depending on such factors as mission length, target hardness, and terrain contour. Landfall, enroute, midcourse, and terminal are descriptive terms of these successively smaller maps. The names are only for convenience, however. Each type of map can be used in other mission segments than its name would indicate. For example, if a mission planner were not constrained by extreme accuracy required by a hard target, then a midcourse map might be selected rather, than the more stringent terminal type map.
After passing through a series of waypoints, the land attack Tomahawk approaches the target area. In the nuclear version, the last map would be fairly close to the intended impact point, any error accumulated by the time the missile reached the target being made up by the larger blast. The smaller yield of a conventional warhead requires precise terminal guidance to destroy a target. Just as the inertial navigation system delivered the missile into the “gate” as it crossed the shoreline so that map correlation could take place, the final portion of the mission starts when the missile is delivered to a predetermined point so the digital scene matching area correlator can take over. After optically sensing the target area, the computer compares the view with a digitally stored “picture” from its memory and performs a correlation, resulting in final maneuvers. In an earlier version the comparison was performed with actual photographic transparencies of target areas. Digitalized versions should allow varied directions for attack and, more importantly, greater ease of target storage, transmission, and reprogramming.
The digital matching terminal guidance system compares digitally stored target views with its optical views of the actual terrain to determine final maneuvers necessary to achieve a hit within several yards of the desired position. The system can provide enough accuracy to allow a conventional warhead to be effective in many applications. There are limitations to an optical system despite such impressive accuracy. Darkness itself is not a limitation since a light is used. Counterdetection could be minimized by using it in only the last seconds of flight. Heavy smog, mist, fog, or shadow conditions might be more difficult to handle and would have to be taken into account in storing a digital target scene as well in designing a computer matching formula.8
Radar altimeters are also susceptible to confusion by environmental factors such as snow. Yet these constraints were considered early in the program. In 1976 an A-7 Navy aircraft, guided by terrain contour matching, flew a “mission” well into Canada without a problem. Some of these seasonal changes could be accommodated by digitally storing new scenes in the computer’s memory. Since these altimeters use an active signal to determine the earth’s profile below the missile, there has been speculation that they can be easily jammed. With a very fine beam moving at high speed it is unlikely an enemy will be able to anticipate exactly where a cruise missile will fly and be able to jam it effectively. Presumably, even if jammed, the missile will merely rely on its accurate inertial navigation system until the next update map is compared. Furthermore, laser ranging systems could likely be used to reduce the jamming threat.
While large portions of Tomahawk’s flight en route to attack a land site are the same for a ship attack mission, there are some important differences. Since by design, contour matching uses variations in terrain, it is useless over water. Similarly, digital representations of maneuvering ships would not be useful for the digital scene matching area coordinator. Therefore, a preprogrammed route is flown and active radar terminal homing is used. Boosted launch occurs normally from torpedo tubes, armored box launchers or the vertical launching system without any necessity to point the launcher. Instead, the missile maneuvers after launch and its strapdown attitude/ heading reference system sets it on course for a target. Tomahawk travels a predetermined, but not necessarily straight, path at low altitude toward an enemy ship. Dogleg maneuvers during this phase can be used to coordinate attack times and to ensure that missiles engage from several different directions, complicating enemy defensive problems. In the final portion of its transit phase, Tomahawk climbs to increase its radar horizon and uses active radar search combined with passive techniques to acquire its target. After lock-on, the missile dives to a sea-skimming mode and maneuvers to make detection more difficult and complicate enemy fire control solutions.
Vulnerability
As with any offensive weapon system, Tomahawk has spurred the opposition to better defenses. In its original conception. Tomahawk would not have needed many selfdefense capabilities. Survivability of Tomahawk is increased by the mobility of its launch platform. For instance, submarines have mobility and protection from the ocean above to increase survivability of their missiles. Tomahawk, flying at a very low altitude, able to circumvent high concentrations of Soviet air defense weapons, was envisioned as being very effective even in its land attack version. A small radar cross section was another one of its key advantages. Radar cross section is the effective size of a target as seen by the enemy radar operator. Having only rough relation to physical size, radar cross section is variable, depending on radar frequency, construction material of the target, and the number of sharp comers and other good radar reflectors. A small radar cross section is important for several reasons. First, acquisition by an enemy radar in a search mode is made more difficult, especially when seen against the ground “clutter” below from an aircraft. Small radar reflectivity also makes it harder for an enemy ground station to pick up a fast-moving, low-altitude Tomahawk which appears suddenly and stays in view for only a short while. Second, the enemy weapon system must be steered onto the Tomahawk before it can be tracked. Third, any missile fired at the Tomahawk must on its own acquire, track, and fuse on the basis of radar return from a small target.
The cruise missile’s radar return is estimated to be a thousand times smaller than a B-52 and a hundred times less reflective than a tactical fighter. It was, therefore, expected that Tomahawk could rely on its small radar cross section and the inability of most Soviet airborne radars to discern a target against the landmass below. This look-down, shoot-down radar capability suddenly became important to the Soviet Union as it saw the United States develop the cruise missile. Similarly, Soviet naval ships began to sprout many high-rate-of-fire Gatling gun point defense systems in reaction to both Harpoon and the eventuality of Tomahawk. Since the Soviets have now focused on U. S. cruise missiles, Tomahawk modernization will likely be necessary.
Higher speed might be an obvious improvement; however, a large penalty in range or reduction in payload would be sacrificed for a marginal speed increase. Additionally, a more powerful engine is likely to mean a hotter exhaust and therefore increased probability of detection from an infrared type seeker. Smaller physical size, although desirable, is unlikely. Increasingly more capable computers will continue to shrink in size, and there is some improvement probable from more efficient and smaller turbofan engines. Even with such advances, though, the limiting factor will be the munitions payload. Sufficiently smaller warheads which have both the explosive power and offer a substantial reduction in overall missile size are not on the technological horizon.
Physical size is not the most important characteristic, however. As long as radar return size can be diminished, then a de facto reduction in size has taken place. Effects from electronic countermeasures (ECM) and “stealth” technology may be the answer to decreasing vulnerability of cruise missiles in the face of improved Soviet air, ship, and ground radars. Each of these types of radars has different weaknesses so that no one electronic fix will make cruise missiles insurmountable. There are reports that ECM will be added to Tomahawk within the next two
t Mother method to reduce cruise missile vulnerability is 0 use stealth technology. By careful external design and .°nstruction, radar reflectivity can be reduced. By lower- ^ ® the amount of energy reflected from the missile, it may -j, Possible to make the enemy operator unable to discern a nnrahawk from background noise. Thus, low-altitude '§ht, evasive attack routes, highly sophisticated electron- j.s’ eombined with stealth techniques and materials will cruise missiles an important part of our arsenal. c As ever, for any offensive gambit the opposing side will unter with a defensive move, so there never was any
^ears ■ Adding electronic means to confuse or jam enemy l ars is important if, as some have suggested, ground- inched cruise missiles being stationed in Europe have °nly a 50% chance of completing their missions success- ully. ECM is far more than simply attaching a black box 0 the on-board computer. Exact techniques are classified 0 Protect the high technology edge that the electronics are ^xPected to give the missile. Since many different, sophis- l(-ated procedures can be incorporated to improve the mis- Ue’s performance, part of the problem has been when to stoP improving and developing new techniques and start Producing upgrade kits. Just as the guidance computer is Programmable to fly the missile over variable routes to the ar8et, so probably will the electronic countermeasures ?°hule be programmable to respond to the expected threat rc»m air and ground defenses along the particular path
Elected.
realistic hope that the Soviet Union would remain vulnerable to cruise missile attack indefinitely. Tomahawk, in the mind of Kissinger, at least was a bargaining chip and to a certain extent it still is. By putting large areas of the Soviet homeland in peril of attack, Soviet defenses can be expected to enlarge. Even conventional high explosives from ground-launched cruise missiles around Europe or from constantly moving U. S. Navy ships and hidden submarines will induce a buildup of Soviet defenses. First, their problem is substantial; cruise missiles are difficult to detect, classify, and shoot down. Advanced techniques will probably keep them a problem. Second, Tomahawk and its variants force Soviet spending on defensive systems, money that cannot be spent in building continued offensive capability for the navy or other forces.
The vulnerability issue and forcing the Soviets to increase their defense is also related to surface ship deployment of the land-attack missiles. Even limited numbers of Tomahawks, particularly the nuclear version, will force this Soviet expense, so some have questioned the need to deploy the nuclear Tomahawk on surface ships. Submarines do offer better survivability for the weapon, but there are other important considerations. Limited magazine space is one critical factor. The same difficulty of detection that makes a submarine an attractive Tomahawk platform makes her ideal to conduct operations in very high threat areas far earlier in a conflict than would be possible for carrier battle forces. Thus, a submarine must balance
between antisubmarine, antisurface, and land attack weapons. Every Tomahawk displaces a torpedo; the relative contribution to the war effort must be weighed carefully by planners. Obviously, priorities will change with the situation. Whatever the mix, the warfighter is likely to want more land attack missiles than submarines alone are programmed to carry, considering their balanced loadouts. Even the vertical launch system planned for the Los Angeles-class submarine will not be able to hold as many as a similar system on board a destroyer. Surface ships, using armored box launchers or the vertical launch system can carry the remainder of programmed weapons. These ships offer an additional advantage by being on the surface. For the last several decades the Soviet Union has been able to concentrate its naval efforts to neutralize American aircraft carriers and submarines. By arming cruisers and destroyers with the nuclear land-attack Tomahawk, Soviet targeting and neutralization problems increase dramatically. Diluting Soviet efforts by broadening their focus to finding, tracking, and targeting many ship classes increases survivability of allied forces as a whole. Limiting deployment to submarines alone will not accomplish this important objective.
Planning
In order for a missile to be tactically and strategically useful, a commander must be able to reprogram it rapidly to engage a target of opportunity or particular importance. Antiship Tomahawk is by design a tactical asset because of its nonnuclear high explosive warhead, shorter range, and open-ocean ship targeting. Strike planning for this version will almost always be a reactive, quick-decision process. Nevertheless, in the face of effective point defense systems protecting most Soviet ships, coordinated planning must be accomplished rapidly to ensure the most effective use of ship and submarine launched Tomahawk; ship or B-52 launched Harpoon; and tactical aircraft. Submarines will most likely not be part of a coordinated attack but will use their weapon of surprise to multiply the effectiveness of Tomahawk. Although not all elements will always be present, careful coordination will still be the key to a successful attack.
In this sense, the computer-based Navy Tactical Data System (NTDS) is not a true tactical decision aid. Forming the basis of most modern combat information centers, this system is still useful in accumulating, processing, and displaying large amounts of information. Yet options for attack, coordination with other forces, or even simple factors such as the effect that surface winds will have on missile performance are not presented to the commander. The computational capability required is minimal, especially compared with the five or six digital computers already on board many Tomahawk and Harpoon capable ships. Adequate support is needed now from shore-based programmers to respond rapidly to real tactical requirements. Tactical decision-making has reached new territory. No longer can the captain merely send a bullet or missile on a direct path to a target a few miles away- Today, the commander must coordinate targeting from many sources, launch 60-mile Harpoon and 400-mile Tomahawk missiles to arrive within seconds of appointed times. Using anything less than the ship’s computers is ridiculous. Tactical aids must meet the demands of these superb new missiles.
software allows the planner a great deal of flexibility while constantly checking for errors that would put the mission at risk, such as risking flying into the ground (called “clobber”) or coming too close to enemy defenses. A mission planner simulates missile flight with the software, keeping his route within the physical limits of speed, climb, and other crucial bounds. Three primary data bases—geography, terrain, and defenses—are used interactively to ensure a successful course to the target. For instance, by manipulating primary files, planners can create an aid to show them how hills along the flight path can be used to veil enemy radars, thereby avoiding detection and clobber. Once an approved route is charted, the digital instructions are recorded and delivered to the launching platform.
The ability to target on board a ship with nuclear land- attack Tomahawk is particularly important. During war, communications will be stretched; no more valuable transmission time should be spent on targeting than the mission and attack time. Preplanned missions are suitable for primary objectives, but successive strikes may need to be concentrated or altered in ways that are difficult to foresee in peacetime. Full reliance should not be placed on land- based mission planning centers.
Another major planning factor will be the mix of the Tomahawk/Harpoon load that a force carries. All three variants of the Tomahawk can be carried and fired from the same launching platforms. The optional loadouts of various mixes on all capable ships in a force are important and must be done concurrently.
Finally, planning must try to correct past problems, although the exact effectiveness of any new weapon system such as Tomahawk is difficult to assess in the public forum. Classified factors of fuzing, accuracy, type of warhead, impact angle, and speed all are different when facing targets as varied as a destroyer in mid-ocean and an aircraft runway protected by revetments. After the series of poor test results and program delay that precipitated a change in project leadership, the public record shows several successful Tomahawk tests in a row. Congress has supported cruise missile development, and the first systems are already in place in Europe and at sea.
Tomahawk II
Also called the medium-range air-to-surface missile, (MRASM), this variant of Tomahawk was to be launched by strike aircraft against land and sea targets. The program, initiated by Under Secretary of Defense William J- Perry in March 1980, was originally viewed with some urgency. It picked up support on Capitol Hill and was funded as a joint program by Congress. The Air Force and Navy funded common airframe development without supporting seeker, warhead, or platform integration. The Navy was initially in favor of the program, but has more recently determined that MRASM was not needed in a Tomahawk format; other alternatives should be explored. The Air Force similarly tried to cancel its participation in 1981. Congressional support did not waiver, but after tepid Pentagon backing delayed initial operational capability by several years, support waned. Both the House and Senate agreed in fiscal year 1984 budget bills to delete essentially all funding for the program, killing the air-to- surface missile in its originally intended form.
Tactical Development
Harpoon gave fleet warfare commanders a quantum leap in their ability to open and add flexibility to the ocean battlefield. An attack radius of 60 nautical miles has given backbone to a previously lame surface action group (SAG) concept. Addition of Harpoon missiles had a synergistic effect on U. S. naval warfare. By allowing several destroyers to loosen-the tight tether that held them to the carrier battle group, not only did they offer attack on an
enemy force from a different angle but also they vastly complicated enemy targeting problems.
Tomahawk missiles will further dilute enemy targeting efforts. First, Tomahawk’s threefold advantage in range °Pens up over 11,000 square miles more than Harpoon cmise missiles can cover. Second, since a ship with anti. P Tomahawk can just as easily carry a land attack ver- ^*°n, every platform must receive a significant amount of argeting effort by the enemy, further diluting energy de- v°ted to carrier battle groups.
Conventional warhead development clearly could consol a large portion of Tomahawk’s future tactical utility.
”e 550-pound Bullpup warhead now used has limited Value against many targets. In particular, the marriage of smart submunitions to Tomahawk will allow the targeting airfields and other distinctive objectives. Specialized technology warhead development is under way in Per services in a number of programs such as the Joint actical Missile System (JTACMS). Commonly known as ssauh Breaker, the warhead on this missile is a joint lo^V-Air Force program for interdiction of second-eche- n Soviet troops. If Tomahawk is to be used as an effec- e conventional weapon, all such advances in small, art warhead technology must be exploited by the Navy. s real-time detailed battlefield surveillance from space
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becomes a reality, flexible retargeting may be able to react to maneuvers of important forces.
Surveillance from every aspect becomes increasingly important when launching against targets several hundred miles past the horizon. For targeting antiship Tomahawk at sea, Outlaw Shark is the Navy’s system to integrate all sources of intelligence on a target and its position in relation to friendly or neutral shipping. A ship’s own radars, passive electronics, and reports from embarked helicopters all are combined with other intelligence, surveillance, and detection systems to provide rapid and current targeting information. The ocean battlefield is becoming more silent as forces are relying more on passive intercepts for targeting, and turn off their own radars to deny the enemy countertargeting information. Since electronic and acoustic emissions can usually be detected by opposing battle forces half again as far as friendly forces can gather useful information, active radar and sonar have to be carefully weighed against the threat of being countertargeted by the enemy.
Outlaw Shark is a system employing netted computers communicating through satellites and other means. In general, satellite communications rely on low-power, direct- path transmissions that have low probability of enemy intercept. Shore, ship, air, and submarine nodes can share information. When passed to a firing platform this target- ress in such systems as Outlaw Shark, the tremendously impressive reach of Tomahawk is of little use.
Other Uses
Tomahawk may fit nicely in future amphibious warfare. Both the cruise missile and the landing craft, air cushion (LCAC) could open more flexible tactical options to any amphibious assault commander. Traditional doctrine has called for several days of pre-landing bombardment by battleships, cruisers, and destroyers. Then frontal assault on a beachhead would follow in an effort to secure a foothold for operations past the littoral.
Around the start of the next decade, when the LCAC enters the force in numbers, waterborne and helicopter assault from over the horizon will be possible, eventually supporting a Marine assault force (MAF) plus a Marine assault brigade (MAB). Amphibious attack from up to 40 miles at sea may alter significantly shore bombardment characteristics. Enemy forces will have to either disperse to cover a wider area accessible to LCACs and helos or to defend an area farther back from potential landing sites. In either case, lucrative targets will be available; command and control sites, ammunition dumps, or runways all present potential Tomahawk destinations. Cruise missiles will
Thanks to terrain contour matching (TERCOM), the land- obviously never replace cheaper bullets or massive tactical
attack Tomahawk can get frequent updates from the ground air strikes, but if used against important inland sites, mis-
to keep it on track to its target. siles can be an important part of future amphibious war
fare.
ing information can be further refined with last minute updates from the ship’s own sensors or those on the scene, such as properly equipped helicopters. Using interactive computer power, graphic displays and rapid calculations provide a tactical planner with an opportunity to vary attack geometry or coordinate the attack with other units. Final, integrated targeting is then preprogrammed in the Tomahawk’s guidance system, listing destination, search methods, and engagement path. Without continued prog-
Arms Control
One primary contraction that led to Tomahawk’s birth was Kissinger’s desire to bargain the cruise missile away during SALT. It is ironic therefore that a major focus of today’s discussion over the weapon revolves around its implications for arms control. START, the successor to SALT, is focused on intercontinental ballistic missiles, not intermediate range weapons such as Tomahawk. Of the
struct
Provide
rapidly simulated over-the-horizon engagements to
Tomahawk family, only the nuclear land attack version would seem to be of any concern, but other versions are involved as well. The conventional variant becomes important, because there are no easily recognized external features to differentiate it from its nuclear relation. Inabil- uy to count numbers of deployed nuclear Tomahawk is a key to arms control considerations of the missile. Until n°w, a crucial assumption has been that each side could Use satellites to count numbers of nuclear weapons the °ther side deployed. Without any observable external characteristics, counting and therefore control evaporate. Air-launched nuclear cruise missiles have incorporated changes to the airframe to ease counting. These function- related observable devices (FRODs) might be used on the nuclear Tomahawk if sufficient motivation were provided through Soviet concessions on other points.
Employment is another principal arms control discussion detail. Since intentions often change, employment is not usually viewed as a good basis for solid negotiation, tomahawk’s slow speed and small payload should make it dear that it is not a first-strike weapon. Yet the nuclear Version is still under debate. In the parlance of arms control, Tomahawk falls in the “grey area” between strategic nnd tactical weapons. Its long range allows it to strike the Soviet Union with nuclear weapons, but without the speed °r power of ICBMs. To be absorbed completely in the neology of grey areas, observable differences and the like 0 not serve our tactical purpose well. How to count, de- Pl°y, and limit these missiles will be debated as missiles are put to sea. If required, the Navy may be able to adapt specifications imposed by international negotiations. ne sooner planned ships have their armored box launches and vertical launch systems full, the sooner America ^*11 have a stronger position from which to bargain. The °viets are not far behind in their own versions of modem euise missiles. Since warhead, engine, and employment cchniques are likely to continue to advance, it is probable uut follow-on Tomahawks will be difficult enough to c°unter that an accommodating balance can be maintained "uthout undermining arms control efforts.
gaining
With each Tomahawk costing more than $2 million, hips will not have a chance to shoot routinely for prac- . Ce- Presumably, enough testing and fleet firings will val- ate missile accuracy and reliability assumptions to en- ?.Ure accurate tactical planning. Those sorts of aggregation j. 8Ures, accumulated over several years of firings, are fine °r the student at postgraduate school or maybe even for a 5fet c°mmander, but they do little for fleet tactical action 'cers (TAO) who must employ Tomahawk in me of war. New or existing on-board computers must be . r°grammed to compute probabilities of success for simu- £d engagements encountered during day-to-day opera- c0t1s by Tomahawk-capable ships. During large fleet exer- es> battle group commanders must be able to reconreal-time assessment for realistic training.
Harpoon missile training has suffered the same problem since fleet introduction. The few trainers that are available are husbanded ashore, away from deployed tactical action officers who could sharpen their skills on real-world scenarios. With over half a dozen digital computers on a modem combatant such as a Spruance (DD-963)-class destroyer, surely at least one can be used to determine the outcome of simulated attacks. To be sure, an inadvertent launch of a Harpoon missile during a fleet exercise in 1981 made everyone extremely cautious of performing even preventative maintenance, let alone training in tactical uses. Tomahawk training must include missile safety, yet operators must have opportunities to use firing panels in simulated engagements and receive real-time feedback on their decisions. These and more structured Tomahawk and Harpoon exercises must become a part of regular battle efficiency competition to ensure that engagement planning and execution are up to wartime standards.
There are also more mundane aspects of training that could prove critical in time of war. For instance, since the radar altimeter is so crucial to Tomahawk’s long-range strike capacity, it must be accurate to very high tolerances. Test equipment to measure and adjust the altimeter must be made simple and reliable. Training must be incorporated in the entire Tomahawk weapons system from the very beginning. Routine test equipment checks and aspects such as planned maintenance of launchers must be addressed, as must the more exciting tasks of strike mission planning.
Conclusion
The family of Tomahawk missiles is not just another weapon system. The antiship and two land-attack versions give form to the concept of distributed offense. The ability to strike sea and land targets from many times farther than was possible only recently must give rise to renewed efforts to use these tactical tools as true force multipliers. By forcing adversaries to pay attention to every Tomahawk platform, resources previously devoted to tracking carriers and submarines will be diluted, increasing survivability for all allied navies. Warhead design must be pursued to give tactical commanders effective options short of requesting nuclear release. As this quantum leap in strike warfare enters the fleet, we are obliged to train, innovate, and master tactical applications in order to overcome our numerical disadvantage. The true perspective of power that Tomahawk has given us has yet to be explored fully.
‘Elmo R. Zumwalt, Jr., On Watch (New York: Quadrangle Books, 1976), p. 81. 2Henry Kissinger, Years of Upheaval (Boston: Little, Brown & Co., 1982), p. 271. 3 The New York Times, 14 August 1982; The Washington Post, 14 August 1982. 4Clarence A. Robinson, Jr., “Navy Planning Tomahawk Program,” Aviation Week & Space Technology, 3 January 1983, p. 15.
5Sea Power, September 1983, p. 22.
6Robert L. Pfaltzgraff, Jr., and Jacquelyn K. Davis, The Cruise Missile: Bargaining Chip or Defense Bargain? (Washington, D.C.: Institute for Foreign Policy Analysis, January 1977), p. 11.
7Joe P. Golden, “Terrain Contour Matching (TERCOM): a Cruise Missile Guidance Aid,” Society of Photo-optics Instrumentation, 29 July 1980, Joint Cruise Missiles Project Office, JCM-M-300.
8Kosta Tsipis, “Cruise Missiles,” Scientific American, February 1977, pp. 20-29.