We are engaged in a complex and ambiguous global war on terrorism, a war that requires the Navy to strive for new, imaginative, and innovative enhancements to its submarine force. The development and employment of submarine-launched unmanned aerial vehicles (UAVs) and unmanned combat aerial vehicles (UCAVs) will enhance greatly the warfighting capabilities of the Navy's "crown jewels" as the service charts its vision for the future.
Beyond "Transformation"
The Bush administration's central theme for the future of the U.S. military is "transformation." The 2001 Quadrennial Defense Review provided a baseline definition: "Rapidly deployable modular forces capable of networked, scalable, distributed, seamlessly joint and combined operations able to defeat adversaries using anti-access, area-denial, and asymmetric capabilities." This quest for transformation has generated intense activity in the U.S. armed services and already has led to radical changes in programs, such as cancellation of the Army's Crusader artillery system and "restructuring" of the Navy's next-generation destroyer program.
In particular, transformation has resonated with the Navy. Under Chief of Naval Operations Admiral Vernon Clark's "Sea Power 21: Operational Concepts for a New Era," the Navy will seek to ensure three fundamental capabilities: "The first is Sea Strike, the ability to project offensive power. The second is Sea Shield, the ability to project defensive power. Third is Sea Basing, the ability to project the sovereignty of the United States of America and to team with and provide enhanced support for joint forces, afloat and ashore, around the world."
Clearly, submarines have critical roles to play in support of all aspects of "Sea Power 21" and the Navy's emerging global concept of operations. But much depends on the successful incorporation of new technologies and systems into current and new-construction submarines and the development of innovative tactics and techniques. In particular, the submarine force's embrace of UAVs and UCAVs offers the promise of transforming the naval battle space consonant with "Sea Power 21" concepts.
The UAVs deployed from attack submarines and converted Trident guided-missile submarines (SSGNs) could play a decisive role in support of the war on terrorism as well as more conventional conflicts, including:
- Clandestine intelligence, surveillance, reconnaissance, and targeting
- Time-sensitive and time-critical strike and battle-damage assessment
- Special operations forces (SOF) support
- Littoral antisurface warfare (ASUW) and antisubmarine warfare (ASW) operations
Highly capable UAVs matched with the firepower of an SSGN could be decisive in taking the fight to the enemy. For example, the SSGN's ability to employ a UAV covertly and launch missiles in response to the real-time intelligence and targeting information it provides would dramatically shorten sensor-to-shooter timelines and, following such action, permit the SSGN to conduct an initial battle-damage assessment. Concomitantly, a SOF commander could use a submarine-launched UAV to provide imagery of planned ingress/egress routes and the area of intended operations. Ordnance from the submarine—or a third-party strike aircraft—could attack SOF-designated targets; the SOF and submarine commanders then could obtain real-time battle-damage assessment and make an on-the-spot decision to reattack. In the ASUW role, a submarine-launched UAV could enable the submarine to covertly monitor ships of interest or combatants as they load out, get under way, and transit areas not accessible to the submarine because of depth or other restrictions. It also could be used to vector U.S. and coalition warships to interdiction points while maintaining area surveillance to ensure friendly forces are not caught by surprise during the operation.
Submarine-launched UAVs also could aid in the suppression of enemy air defenses through electronic jamming or decoy payloads, as well as direct strike missions of time-critical targets, such as mobile Scuds and command-and-control sites, detected by the UAV using electro-optic, infrared, synthetic-aperture radar, or active electronically scanned array radar. In addition, a submarine might launch several small, expendable, and highly maneuverable UCAVs, each armed with guns and cameras and "flown" over a video link, to engage and blunt a small-boat "swarming" attack against U.S. or allied forces in the littorals—providing an asymmetric response to an asymmetric attack. The effects of UAV operations from submarines look to be far-reaching, but much depends on Navy investment in critical enabling technologies that would make real the link up of these two platforms.
The Navy must address issues of organization, training, and interoperability. It must determine how submarine-launched UAVs will be integrated into the joint order of battle and how decision makers at all levels will gain an understanding of the capabilities and constraints inherent in their employment. Plans and procedures to include submarine-launched UAV missions in joint air tasking orders or to provide data to combined air operations centers or to integrate such UAVs into scalable, distributed, off-board sensor and information networks also must be addressed. In addition, who will "fly" the UAVs when man-in-the-loop actions are required? One option is to train submarine personnel as UAV pilots and provide them with additional certifications, designators, and career path options.
Enabling Technologies
Between the United States and the United Kingdom, there are some 20 manufacturers of 73 different UAVs. Worldwide, another 44 manufacturers produce some 140 different vehicles. With relatively straightforward modifications, reengineering, or scaling, many of these UAVs could be adapted for submarine use, minimizing much of the cost, scheduling, and engineering risks. Conversely, new "clean-sheet" designs should be considered.
Whatever UAVs are picked, they must have a militarily useful flight profile in terms of altitude, range, and payload. They must be all-weather vehicles incorporating stealth technologies and capable of altitudes of 10,000-25,000 feet, endurances of 8-12 hours, and ranges of at least several hundred miles, with the ability to carry interchangeable or modular payloads weighing hundreds of pounds. A case also can be made for small, cheap, high-flying, maneuverable UAVs outfitted with nothing more than moderate-resolution cameras and possibly olfactory sensors. These expendable platforms could be of high value in providing real-time videos of enemy operations, thereby offering commanders the opportunity to rapidly respond with available forces.
There are significant engineering difficulties in designing (or reengineering) a UAV that can launch from a submerged submarine and then transition to stable flight, but they are solvable. The Navy and industry already have firm knowledge of the underwater-launch techniques necessary for heavy missiles and torpedoes—since 1955, they have developed five submarine-launched ballistic missiles and a number of torpedoes, each more sophisticated, capable, and often heavier than its predecessor. The engineering and physics challenges of launching vehicles from submerged submarines should not be show stoppers.
In addition, recovery of UAV payloads should not be ruled out. Some submarine-launched UAV variants might be expendable and programmed to provide data over a communication or video link prior to self-destructing or crashing; others, with more expensive or unique payloads, could be programmed or remotely piloted for recovery by friendly surface platforms or forward operating locations. The UAV might return to the submarine and drop its payload of sensor capsules for recovery and onboard analysis by the submarine.
Is a UAV recoverable by a submarine? The short answer is likely yes. Good aircraft characteristics do not necessarily translate into good submersible characteristics, and it is difficult to make an aircraft watertight. But within the bounds of such limitations, maximum allowed sea pressure, industry and government could explore an aircraft that lands on the water, reconfigures its fuselage and wings, submerges, and then remates with a submerged submarine. Recall that both underwater launch and recovery are being planned for submarine unmanned mine-reconnaissance systems.
Several UAVs in the U.S. inventory could be adapted for internal stowage and launch from a torpedo tube, a modified D-5 ballistic-missile launch tube, a modified SEAL dry-deck shelter, a submarine trash disposal unit, or a universal modular mast. The compatibility of candidate UAVs with other capsule-launch concepts, such as the broaching universal buoyant launcher and the stealthy affordable capsule system, also could be evaluated for engineering feasibility and the degree to which size, weight, and complexity can be traded to achieve useful military UAV capabilities. Only by aggressively engaging the issues can the Navy overcome these difficulties and maximize the limits of the trade-space key to achieving a viable concept of operations.
Numerous sensors, communications, payloads, and control package alternatives are available for consideration. Interchangeable, mission-dependent payloads might include electro-optic, infrared, synthetic-aperture radar, active electronically scanned array radar, electronic support measures sensors, olfactory sensors, nuclear, biological, and chemical packages, and air-dropped sensors with communications links. Retrievable sample capsules should not be ruled out. Finally, UCAVs—analogous to today's Hellfire missile-carrying Predator—capable of loitering over the battle space and attacking targets of opportunity, could be a key multiplier for the submarine and SOF forces operating ashore. Many of these sensors already are used on various airborne platforms, including UAVs; modifying them to accommodate submarine launch is unlikely to present technical problems.
Because there is no broadband communication connectivity with submarines below periscope depth, exchanging data between the launching submarine and the air vehicle, even if both had nominal satellite access, probably could be done only when nuclear submarines and guided-missile nuclear submarines had their communications masts above water. This sort of connectivity may be acceptable in scenarios that do not unnecessarily require the submarine to give up its primary asset—stealth.
One Way Ahead
There currently is no funding in the Program Objective Memorandum for the development of submarine-launch-capable UAVs. Thus, the first step must be to provide dollars to begin significant analysis and research and development. In addition, notional development timelines extend all the way to 2010-2015, a torturously slow path.
The Navy should work with the Defense Advanced Research Projects Agency to take a fresh look at developing future submarine UAVs that push the edge of today's thinking and accelerate the transition of worthy technologies. It also must begin to think through how submarine-launched UAVs will be integrated and fused into the joint battle space and information networks. Man-in-the-loop interactions to fly or otherwise control and direct UAVs will be necessary to some degree. Should submariners gain a new designator as UAV pilots?
Highly capable submarine-launched unmanned aerial vehicles can be an operational reality. They would enhance the capabilities of submarines by further integrating these warships into distributed sensor and information networks while extending their on-scene, real-time combat radius by hundreds of miles. When this happens, defense planners, military commanders, and the President will have many more arrows in their quivers.
Dr. Hancock, a former submariner, works for the Schafer Corporation in Arlington, Virginia. He wishes to thank Dr. Scott C. Truver of Anteon Corporation for his contributions to this article.