The recently announced Indo-Pacific Outlookby the Association of Southeast Asian Nations (ASEAN) at the 34thSummit indicates the Southeast Asian perspective on the evolving geostrategic environment. Unsurprisingly, ASEAN highlights cooperation, stability, peace, freedom of navigation and other values in the statement. The Outlook, however, leaves a question: how will ASEAN protect these values when diplomatic measures fail?
Under the ASEAN way, it would not be realistic to expect strong words such as those implying the use of force in any official statement, but member countries bordering critical straits could indirectly convey the message by demonstrating relevant defense capabilities. Among a variety of defense capabilities, tracking foreign submarines through enhanced undersea surveillance could be a relevant option.
The major strategic significance of Southeast Asia in the Indo-Pacific region is mostly found in several critical sea lanes where various powers’ military assets travel through channels connecting the two oceans. Under the United Nations Convention on the Law of the Sea (UNCLOS), military vessels and aircraft enjoy the right of innocent passage through these sea routes, whether classified as international straits or archipelagic waters, and coastal countries track these movements. Modern technology makes it feasible for coastal states to readily track foreign military aircraft and surface vessels, a task that is more about safety than security. But tracking submerged submarines is another matter with a much higher barrier to entry.
In the face of complicated hydrographic conditions along with the improving stealth of submarines, there are high requirements for detection in terms of sonars, training, joint operations, and other elements of undersea surveillance. Therefore, successfully tracking submarines requires a high degree of military professionalism and capability. But once successfully tracked and trailed, a submarine receives a clear but private message of deterrence.
This kind of covert deterrence would fit the geopolitical context in Southeast Asia. Firstly, it is generally legitimate for a littoral state to detect underwater entities because submarines should sail on the surface during innocent passage in territorial waters, while a submerged transit is acceptable under UNCLOS in passing sea routes and international straits. But only when a littoral state can identify the locations of foreign submarines transiting underwater can it determine whether UNCLOS is violated or obeyed. In other words, Southeast Asian countries have a sovereign right and legal obligation toward undersea surveillance.
Tracking submerged submarines also presents a credible level of readiness for uncertainty. Overt exercises can be tailored for specific scenarios to prove certain levels of joint operations and other tactical skills, while bilateral and multilateral exercises highlight partnership, alliance, and other interstate security ties. Exercises are often much broader than the single capability of tracking submarines. Exercises, however, are either fully or semi-planned, and tracking foreign submarines is a truly dynamic encounter between two sides without an advance arrangement. Furthermore, Southeast Asian countries already have routinely conducted various bilateral and multilateral exercises with regional and extra-regional counterparts.
Tracking submerged submarines is usually beyond the microscope of conventional and social media, and can avoid the open hostility or other forms of public outcry that often transpire after close encounters between surface vessels. As the detecting side can deny any information on the tracking, publicity of the event would be more controllable compared with open statements or actions. For the country of the tracked submarine, such encounters are usually negative for national pride and military professionalism, so decision-makers would not have much incentive for revealing the encounter.
Improving Hardware and Challenges Ahead
Since the end of the Cold War, Southeast Asian navies, particularly those of Indonesia, Malaysia, and Singapore, have built up their anti-submarine warfare (ASW) capabilities, including through several types of undersea sensors. These three countries have acquired survey vessels to establish their individual hydrographic databases. They have also procured state-of-the-art anti-submarine warfare helicopters such as the Super Lynx, S-70B, and AS-565MBe and deployed them on their respective frigates and corvettes which have towed or hull-mounted sonars. Furthermore, all three navies possess submarines to play the role of targets during training.
Some characteristics impose challenges on the ability of Southeast Asian countries to track submarines. Large areas of territorial waters are natural obstacles for Malaysia and Indonesia. The numbers of maritime survey vessels they have in service are rather small for accumulating and updating their hydrographic data. By the same token, these two countries’ sensors and platforms, including ASW helicopters or ships, are likely not numerous enough to cover their broad territories or responsively deploy to where contacts are found.
Thanks to its tiny size, Singapore’s assets cannot be geographically diluted, but it shares other constraints with its neighbors, including a lack of fixed-wing ASW aircraft. The Indonesian CN-235 and the Singaporean Fokker-50 maritime patrol aircraft (MPA) only have limited ASW capabilities, and Malaysia’s smaller Beech-200 MPAs have no payload space for ASW weapons. Finally, operational experience is another common challenge for these three countries, as they began to introduce their sophisticated ASW assets mainly in the post-Cold War era where opportunity for practice was slim.
Currently, the three navies are on a trajectory of improving their ASW capabilities, such as through the towed sonar arrays found in Malaysia’s upcoming frigates and Indonesia’s plan of building underwater surveillance systems. These efforts would gradually make tracking foreign submarines underwater more feasible in the foreseeable future.
Unlike in the Cold War-era, some Southeast Asian countries, especially these three bordering critical straits, do not have empty arsenals. Although their defense capability is still inferior to most extra-regional powers, some wise and tailored applications of their military assets would support ASEAN agenda’s beyond diplomatic and economic means. Successful tracking foreign submarines would make the ASEAN Outlook more valid in the Indo-Pacific geostrategic landscape.
Shang-su Wu is a research fellow at the S. Rajaratnam School of International Studies (RSIS), Nanyang Technological University in Singapore.
Featured Image: A Chinese submarine transits in the Yellow Sea (Wikimedia Commons)
In recent years the Pentagon has doubled down on a Pacific focus. It has published a new Pacific strategy and the individual services have been burning the midnight oil to write their own new concepts oriented around the Pacific.1 The Navy has released its classified new concept Distributed Maritime Operations,2 the Army has its Multi-Domain Operations concept,3 and the Marines are still working on Expeditionary Advanced Base Operations.4 All three concepts are predicated on an ability to maneuver through and within the First Island Chain. They assume the future operating environment will be heavily contested and involve threatened areas much farther from the central battlefields than the military has experienced in recent decades. In his recent planning guidance, the new Commandant of the Marine Corps warned:
“Potential adversaries intend to target our forward fixed and vulnerable bases, as well as deep water ports, long runways, large signature platforms, and ships…The ability to project and maneuver from strategic distances will likely be detected and contested from the point of embarkation during a major contingency.”5
Notably, this would negatively impact logistics and sustainment operations across the Pacific theater, and not just at the bleeding edge of the combat zone.
All the concepts seek to leverage distribution and rapid maneuver – whether through distribution of austere bases, task forces, or naval vessels. While they are intended to be broadly applicable the concepts are optimized for operations in the Western Pacific to counter a rising China and her military. Essential to all of these concepts is intra-theater mobility – moving lethality to the decisive point, but it has yet to be addressed in a meaningful way in acquisition and modernization priorities. The services have poured much needed resources into platforms and systems that can kill and destroy, but they have neglected to invest in operational mobility.
It does not appear that U.S. allies and partners in the region have the stomach for a larger basing footprint that would allow forces to be permanently or rotationally based forward. This begs the question – who is doing mobility and logistics? How will Army and Marine Corps advances in lethality actually reach a far-flung Pacific battlefield? How would the “forward deployment of multiple High-Mobility Artillery Rocket System (HIMARS) batteries armed with long-range anti-ship missiles” that Commandant Berger envisions actually happen in a contested environment?6
Shortfalls in Pacific Mobility
Today the intra-theater mobility requirement is largely filled by Expeditionary Fast-Transports (EFPs). These aluminum, double-hulled vessels are relatively new to the fleet but have been a continual disappointment. They have not been able to meet critical requirements for ship-to-ship transfers of supplies.7 They have sustained hundreds of thousands of dollars of damage in trans-oceanic voyages, voyages they would be needed for in a conflict.8 They have been plagued by maintenance issues. And perhaps worst, they have trouble operating in the open ocean because of the higher sea states there. An Operational Test and Evaluation Report concluded “The necessity of avoiding high sea states while transiting is an operational limitation that could be significant.” And “To utilize the speed capability of the ship, seas must not exceed Sea State 3 (significant wave height up to 1.25 meters).”9 A Department of Defense Inspector General report found 28 total deficiencies with the vessels in levels ranging from minor to severe, which means the deficiency in question “Precludes mission accomplishment.”10 The report found more than half of these deficiencies were either related to the vessels ability to meet cargo carrying requirement or network with the fleet – probably the two most important capabilities for the platform’s success.
Designed for inshore transport, the EFPs had been used successfully as short-haul commercial ferries between the Hawaiian Islands before the design was chosen by the Navy. But they are largely unsuitable for longer trips, like the nearly 1,600-kilometer trip between Okinawa and Tokyo, or the 1,700-kilometer trip between Okinawa and Manila, or the similarly lengthy trip to Guam. Today many of these trips are made by air or by Marines embarked on large, amphibious ships like the America class which may be too vulnerable and valuable to operate inside an enemy anti-access, area-denial envelope (A2/AD). The demand for these amphibious ships far outstrips the supply. Despite a longstanding (but recently waived) requirement of 38 amphibious ships set by Marine Corps leaders, the Navy’s current shipbuilding plan will not reach that number until 2033 or perhaps ever.11 Other sources, like the Heritage Foundation have argued that the requirement is as high as 45 amphibs.12 The Marine Corps went so far as to note this in their 2016 Marine Operating Concept that “We will likely continue to fall short of the number of amphibious warfare ships to meet CCMD operational demands…”13 Other transport programs like the Navy’s Common Hull Auxiliary Multi-Mission Platform (CHAMP), are still in the concept stages are likely fall in priority to other Navy programs because they are auxiliaries.14
A new platform for intra-theater mobility can share some of the burden carried by the larger amphibious ships.
Intra-theater mobility is critical to future Marine and Army operations. Littoral Operations in a Contested Environment specifically calls for the capability “…to employ scalable landing forces using a variety of platforms including amphibious ships as well as alternative capabilities…”15 But the short list of available platforms makes clear that this is not possible without acquiring new platforms or significantly modifying existing platforms. Seconding this sentiment, Commandant Berger noted in his planning guidance that:
“Our naval expeditionary forces must possess a variety of deployment options, including L-class and E-class ships, but also increasingly look to other available options such as unmanned platforms, stern landing vessels, other ocean-going connectors, and smaller more lethal and more risk-worthy platforms…We must also explore new options, such as inter-theater connectors and commercially available ships and craft that are smaller and less expensive, thereby increasing the affordability and allowing acquisition at a greater quantity.”
This specific capability gap is in addition to the yawning general capability gap the Navy is facing in logistics and sealift capability. A recent report by the Center for Strategic and Budgetary Analysis made clear their belief that the Navy and associated institutions were woefully deficient in sealift capability in the opening sentence of their report, “The current and programmed defense maritime logistics force of the United States is inadequate to support the current U.S. National Defense Strategy and major military operations against China or Russia.”16 Specifically the roll-on/roll-off (RO/RO) ships that Marines forces rely on to move tanks, light armored vehicles, HIMARS, and logistics vehicles in bulk are plummeting below acceptable readiness. “…even with service-life extension funding for 22 ships… 30 of 65 RO/RO vessels could age out within the next 15 years.”17 It is also worth noting that this scathing assessment did not even consider the potential requirements for emerging Marine Corps concepts requiring greater dispersion.
It would be negligent not to note the role of Marine and Air Force airlift – critical in moving around forces in theater, but it is not nearly enough. Not only are the available air transport options questionably survivable in the projected operating environment, but there are just not enough of them to do the whole job. Recall the infamous Millennium Challenge event where retired Marine General Paul Van Riper’s red force would have massacred the blue forces arriving on waves of rotary-wing aircraft.18 It is also likely that much of the extant airlift capacity would be tied up supporting expeditionary airfields per the Marines’ EABO concept or the Air Force’s “Rapid Raptor” concept leaving little to ferry ground forces.19
Other voices have also called for plugging the maneuver gap in the Pacific with new surface vessels. Douglas King and Brett Friedman recently called for a “Fighting Connector” in War on the Rocks that:
“…would use sea lines of communication to fill the gap between amphibious assault ships, sea-based assets, and Expeditionary Advance Bases (EABs) until shore-based threats are reduced. The size of the fighting connector would be in the range of sloop or small corvette class ships, displacing roughly 500 to 2,000 tons — a step or two smaller than the littoral combat ship.”20
A recent study by the Heritage Foundation noted “The Corps must work with the Navy to develop smaller, lower-cost ships that are better suited to the type of dispersed operational posture implied by LOCE.”21 And the Marine Corps itself has noted that it is deficient across the range of capabilities required to perform EABO. The authors of the 2016 Marine Corps Operating Concept summarized:
“The Marine Corps is currently not organized, trained, and equipped to meet the demands of a future operating environment characterized by complex terrain, technology proliferation, information warfare, the need to shield and exploit signatures, and an increasingly non-permissive maritime domain.”22
The Marines and the Army are investing in much needed, new ground vehicles and long-range, precision-fires capabilities essential for contributing to sea control or sea denial from the landward side of the battlefield. But the Navy and Air Force have also prioritized offensive systems like the FFG(X) and the F-35 programs. Even the Marines’ new CH-53K, ideally suited for moving vehicles, cannot cover the distances required by the theater with an external load.
This issue of lift is existential for Army and Marine operations in the Pacific. The theater is massive – in many cases hundreds or thousands of miles away from U.S. installations. The Marine Corps intends to distribute its forces widely, and has already begun. There is a new rotational force in Darwin, Australia, and a plan to move forces to Guam from Okinawa. This is good news, but these far-flung garrisons need platforms that can move them rapidly and in a survivable way to where they are needed in conflict. And these platforms need to be able to carry the gear essential to sea control like HIMARS rockets and G/ATOR radars, not just grunts.
If the United States wants to compete, deter, and win in a potential conflict its military needs to be able to move troops around the theater in question at will. To do this will require a reallocation of acquisition priorities and investments.
Walker D. Mills is an active duty Marine Corps infantry officer. He is currently studying Spanish at the Defense Language Institute. These views are presented in a personal capacity.
 Indo-Pacific Strategy Report: Preparedness, Partnerships and Promoting a Networked Region. Department of Defense (Washington, D.C.: 2019) https://media.defense.gov/2019/Jul/01/2002152311/-1/-1/1/DEPARTMENT-OF-DEFENSE-INDO-PACIFIC-STRATEGY-REPORT-2019.PDF.
 “The U.S. Army in Multi-Domain Operations 2028,” TRADOC Pamphlet 525-3-1, U.S. Army (2018) https://www.tradoc.army.mil/Portals/14/Documents/MDO/TP525-3-1_30Nov2018.pdf.
 “EABO,” Marine Corps Warfighting Lab, webpage. Accessed July 15, 2019, https://www.candp.marines.mil/Concepts/Subordinate-Operating-Concepts/Expeditionary-Advanced-Base-Operations/.
 “Commandant’s Planning Guidance: 38th Commandant of the Marine Corps,” U.S. Marine Corps (2019) 1-4.
 “Commandant’s Planning Guidance,” 3.
 Brock Vergakis, “Report: Navy Ship Designed for Fast Transport Has Problems,” Military.com (28 April, 2018) https://www.military.com/daily-news/2018/04/28/navy-ship-designed-fast-transport-has-problems-report-says.html.
 Nick Stockton, “Yar! The Navy is Fixing Its Busted High-Speed Transport Ships,” Wired Magazine (January 20, 2016) https://www.wired.com/2016/01/yar-the-navy-is-fixing-its-busted-high-speed-transport-ships/.
 “Follow-on Operational Test and Evaluation (FOT &E) Report on the Joint High Speed Vessel (JHSV),” memo (September 22, 2015) https://news.usni.org/wp-content/uploads/2015/10/9-22-15-Follow-On-Operational-Test-and-Evaluation-FOTE-Report-on-the-….pdf#viewer.action=download.
 “Expeditionary Fast Transport Capabilities,” Inspector General of the Department of Defense (April 25, 2018) 6-7. https://www.oversight.gov/sites/default/files/oig-reports/DODIG-2018-107.pdf.
 Dakota Wood, “Rebuilding America’s Military: The United States Marine Corps,” The Heritage Foundation (March 21, 2019) 39. https://www.heritage.org/defense/report/rebuilding-americas-military-the-united-states-marine-corps.
 “U.S. Navy” The Heritage Foundation (October 4, 2018) https://www.heritage.org/military-strength/assessment-us-military-power/us-navy.
 “Marine Corps Operating Concept: How an Expeditionary Force Operates in the 21st Century,” U.S. Marine Corps (September 2016) 20. https://www.mcwl.marines.mil/Portals/34/Images/MarineCorpsOperatingConceptSept2016.pdf
 Megan Eckstein, “Navy Wants 2 Variants Next Common Auxiliary Hull: One for People, One for Volume,” USNI News (January 16, 2019). https://news.usni.org/2019/01/16/navy-wants-2-variants-next-common-auxiliary-hull-one-people-one-volume.
 “Littoral Operations in a Contested Environment,” U.S. Marine Corps (2017)17. https://news.usni.org/2017/09/26/document-marine-corps-littoral-operations-contested-environment-concept.
 Timothy A. Walton, Harrison Schramm and Ryan Boone, “Sustaining the Fight: Resilient Maritime Logistics for a New Era,” Center for Strategic and Budgetary Analyses (April 23, 2019) i. https://csbaonline.org/research/publications/sustaining-the-fight-resilient-maritime-logistics-for-a-new-era/publication.
 Ibid., 85.
 Micah Zenko, “Millenium Challenge: The Real Story of a Corrupted Military Exercise and Its Legacy,” War on the Rocks (November 5, 2015) https://warontherocks.com/2015/11/millennium-challenge-the-real-story-of-a-corrupted-military-exercise-and-its-legacy/.
 Blake Mize, “Rapid Raptor: getting the fighters to the fight,” U.S. Air Force Public Affairs (February 20, 2014) https://www.pacaf.af.mil/News/Article-Display/Article/591641/rapid-raptor-getting-fighters-to-the-fight/.
 Douglas King and Brett Friedman, “Why the Navy Needs a Fighting Connector: Distributed Maritime Operations and the Modern Littoral Environment,” War on the Rocks (November 10, 2017) https://warontherocks.com/2017/11/navy-needs-fighting-connector-distributed-maritime-operations-modern-littoral-environment/.
 Wood, “Rebuilding America’s Military,” 40.
 “Marine Corps Operating Concept,” 8.
Featured Image: EAST CHINA SEA (Feb. 4, 2019) – Marines assigned to the 31st Marine Expeditionary Unit (MEU) board an MV-22 Osprey assigned to the “Flying Tigers” of Marine Medium Tiltrotor Squadron (VMM) 262 aboard the amphibious assault ship USS Wasp (LHD 1) prior to flight operations. (U.S. Navy photo by Mass Communication Specialist 1st Class Daniel Barker)
As discussed in Part I, it is clear that NAVSEA needs to undertake a project now to completely re-engineer the next generation of SSNs. The old bloated SSN(X) (now “New SSN”) concept should be rejected entirely because it is more of the same, but bigger and more expensive. Instead, the Navy should go for a new class of SSN that is far smaller and cheaper than the current Block 5 Virginias.
The key components of a reimagined, redesigned “compact” SSN include four major changes from existing SSN designs. Namely, it can refocus the SSN and its systems on its original roles of anti-shipping and ISR, eliminating the vertical launch tubes and enhancing the horizontal launch tube systems. It can re-engineer the nuclear power plants to result in power plants that are safer, simpler, more compact, and cheaper to build and operate. It can also re-engineer the rest of the SSN systems to increase automation, optimize crew work processes, and to reduce the total required ship’s complement. Finally, it can modernize and revise the SSN’s weapons system to provide a wider range of weapons capability and increase the number of warshots deployable in a compact hull form
The net result of the proposed changes should be a more effective, more capable, yet smaller and cheaper SSN that the U.S. Navy can afford to build and operate in numbers sufficient to meet existing and growing near-peer naval challenges of the mid-21st century. Such a submarine would be expected to displace well under 5,000 tons.
In recognition that major ship class redesigns with “great leap forward” technology improvements carry additional development risk and incur longer development timeframes, it is good practice for the Navy to pursue these advances in a relatively small block build or in technology insertion increments (as used on the Virginia-class boats).
The proposed Next Gen “New SSN” class should consist of the following minimum of two blocks.
Set an overall objective for Block I to build a new SSN of not more than 4,500 tons, but less if feasible, and a crew size of not more than 70 officers and sailors, and less if achievable. The design should strive to reduce the volume of operations spaces, engineering spaces, crews’ quarters, storage, and support spaces accordingly. Total construction cost should aim for significantly less than $2 billion each in 2019 dollars.
The ship should include a new secondary propulsion plant system utilizing hybrid drive – i.e., eliminating the main propulsion turbines and reduction gears, and utilizing only two relatively large turbo-generators with electric drive, as used on the Colombia SSBN class design. This design provides a significant noise reduction and propulsion plant size reduction. It can also consider using a shrouded propulsor with built-in electric motor external to the pressure hull. The new design can include a new reactor plant with next-gen automation and design simplification, as a scaled-down version of the USS Gerald R. Ford A1B plant design.1 Consider, and develop as available, alternatives to conventional lead acid battery banks for emergency power generation, including use of next-gen hydrogen fuel cells and/or advanced battery technology to increase power availability in event of a prolonged reactor shutdown, and/or to provide enhanced quiet operations for limited periods of time.
The new design should retain the standard 21-inch torpedo tubes for use with heavyweight torpedoes (Mk 48 ADCAP) and submarine launched cruise missiles (i.e., Maritime Tomahawk ASCMs, Naval Strike Missiles, etc.) relevant to surface ship attack. It should also add new 13-inch torpedo tubes to deploy Mk 46/54 lightweight torpedoes relevant to ASW. This will result in an overall increase in the number of warshots that a submarine can carry per unit hull volume. The design should also include next generation torpedo defenses including both towed passive softkill systems and hardkill kinetic weapons with respective launch tubes, as already in use on surface combatants.
Eliminate the vertical launch tubes. For those who say the Navy still cannot afford to give up the deep strike land attack mission (because of now-obsolete fears of naval irrelevance in 21st century warfare), we still have all of the existing Virginia-class boats that already have been delivered, and those that have already been ordered, including those Block 5s with VPM – which still provide a robust deep strike land attack capability in the SSN fleet today and for the next 40 years. If it is really thought necessary that the Navy provide the deep strike land attack capability from submarines, then build new SSGNs to provide that capability starting in the early 2030s as the existing SSGNs retire– that mission, however, does not require SSNs as platforms. If there is any resulting temporary “gap” in needed launchers it may be filled with surface warships and aircraft.
To be ready for unmanned systems and networked warfighting capabilities the new design should account for modularity and open architecture in submarine system interfaces (communications and combat data management systems) to enable effective networking with off-ship platforms including unmanned undersea vessels (UUV), unmanned surface vessels (USV), and aircraft, both manned and unmanned. Submarine systems must be interoperable within the evolving architecture of Naval Integrated Fire Control – Counter Air (NIFC-CA) and Cooperative Engagement Capability (CEC), and be flexible within the Navy’s Distributed Maritime Operations (DMO) doctrine.
While developing and building the Block 1 new SSN, the Navy can launch a new reactor design program to adapt a generation four reactor plant to provide numerous advantages for naval submarine power over current technology pressurized water reactor (PWR) plants. Perhaps the most likely candidate is a molten salt reactor (MSR)2, which is part of the current crop of commercial generation four reactor plants already under development in the U.S. and elsewhere including the People’s Republic of China. Liquid MSR technology, in experimental reactor use since the 1960s, has several advantages over PWR plants. The reactor does not have a solid “core” that requires replacement in order to refuel the reactor, and the reactor can be refueled at will during regular maintenance availabilities. It also does not require cutting open the pressure hull or making other intrusive openings to the plant to “gas up.” This design still delivers extremely long endurance between refueling operations, and results in a significant reduction in hull lifetime operating cost. It also provides extended hull operating lifetime without enlarging the hull to accommodate a larger reactor plant needed to yield a life-of-ship reactor.
MSR reactors are intrinsically safe unlike PWRs (there is no meltdown risk because the reactor itself, along with its fuel, is already molten), thus significantly reducing the safety requirements and operating limitations necessary with PWRs. MSR reactors also operate at one atmosphere of pressure, eliminating the need for very heavy steel reactor pressure vessels and primary coolant system components, thus significantly reducing the weight and size of the nuclear power plant. This greatly reduces the effects of thermal stress due to rapid cooldown associated with thickly walled steel pressure vessels.
MSR reactors operate at far higher temperatures than PWRs, thus allowing the use of more efficient high temperature steam secondary plants, reducing both the size and weight of the secondary plant. This also yields a much higher overall thermal efficiency for the entire power plant, meaning that a MSR plant of a given capacity in MW thermal power (MWt) produces the same motive power as a much larger PWR plant.
MSR reactors do not need high speed main coolant pumps as do PWRs, hence are intrinsically quieter than today’s submarine power plants. MSR reactors can use a wide variety of cheaper and more widely available reactor fissionable fuels, including, amazingly enough, spent fuel from conventional PWRs, lower enriched uranium fuel, depleted uranium, and thorium. When the MSR fuel is completely spent and discarded as waste, it is far less radioactive over far shorter decay timeframes than spent fuel from conventional PWRs.
Overall, MSR reactors are significantly safer, smaller, lighter, simpler, more efficient, and cheaper than PWRs – all of which will contribute significantly to reducing the size and cost (both construction, and operating) of next gen SSNs. The end result of a successful integration of MSR technology into SSNs will be a much more compact, simplified, and capable sub in addition to being much less costly to build and operate.
This investment in a new nuclear propulsion technology approach will undoubtedly generate lots of pushback. People, including professionals, find comfort with the familiar, and more people than not simply dislike change because it creates uncertainty. However, nuclear propulsion itself was perceived as a big threat to the status quo by many senior leaders in the fleet and at Pentagon in the late 1940s and 1950s when Admiral Rickover upset their apple carts. Rickover managed to keep his program operational and funded by going over the heads of the senior uniforms, and cultivated “protection” from the senior uniforms via senior members of Congress who controlled naval budgets and authorizations for ship construction.
Rickover actually considered several alternative technology approaches before finally settling on a single approach via PWRs. His team developed a liquid sodium cooled reactor plant, or “Liquid Metal Fast Reactor” (LMFR) first as a prototype (S1G) in West Milton, New York, and then installed the reactor (S2G) in a SSN, the USS Seawolf (SSN-575). These liquid metal reactor plants enjoyed several but not all of the same advantages listed above for MSR plants, but also suffered significant limitations particular to liquid sodium that are not issues with MSR plants, including a tendency to leak, and the fire hazard presented by such leaks of liquid sodium metal. This reactor design was abandoned in 1956, and the liquid sodium reactor in Seawolf was later replaced with a PWR reactor. But today’s fourth generation MSR technology is both very different from and more advanced than that used in the early liquid sodium plants.
It is clearly time for Naval Reactors to give MSRs a very hard look, including designing, building, and operating a prototype. If it works out well, then design one into the second or a subsequent block of the new SSN submarines, likely by the late 2020s to early 2030s. It would likely result in a smaller displacement hull with greater capability, quieter, and lower cost to build and operate than those based on traditional PWR propulsion technology. Even if MSRs are not able to deliver all that is expected, there are other fourth generation reactor technologies that may be feasible. Even a next generation LMFR may be worth reconsideration, given what we know now that Admiral Rickover and his team at Naval Reactors did not know in the mid-1950s.
This block development approach to a new SSN, a next generation of smaller, more capable, and far cheaper to build and operate SSNs, will lead the U.S. Navy to building a numerically larger yet more capable SSN force. Instead of the age old “capacity vs. capability” argument between opposing sects of naval planners and advocates, the result will be both much more capacity and more capability. The proposed smaller, cheaper, yet more capable sea-control focused attack SSNs will help the U.S. cost-effectively meet the immediate and growing threat of peer naval adversary submarine fleets today and for decades to come.
Mr. Truitt is a veteran Cold War era SSN sailor, qualified nuclear reactor operator, and civilian nuclear test engineer as well as a degreed civil engineer, environmental scientist, and civil/environmental project manager with extensive experience at both naval and civilian nuclear facilities as well as military and civilian facilities development. His interest today as an author is in forward looking military preparedness and improvements in both capacity and capability of U.S. naval forces.
2. Albert J. Juhasz, NASA Glenn Research Center, Cleveland, Ohio 44135; Richard A. Rarick and Rajmohan Rangarajan Cleveland State University, Cleveland, Ohio 44115; “High Efficiency Nuclear Power Plants Using Liquid Fluoride Thorium Reactor Technology; https://ntrs.nasa.gov/search.jsp?R=20090029904 2019-04-02T18:59:43+00:00Z
Featured Image: Virginia-class submarine USS Missouri. (General Dynamics Electric Boat photo courtesy of Edward S. Gray, Secretary, Missouri (SSN-780) Commissioning Committee.)
Suppression of enemy air defenses (SEAD)1 is a mission based on recognizing that air defenses have become increasingly lethal, effective, and must be suppressed in order to allow air operations to be conducted with dramatically reduced loss rates. SEAD has evolved since WWII as a direct result of lessons learned in combat. It has established doctrine, established tactics, specialized force structure, specialized weapons, and trained and experienced personnel that plan and execute the mission. The U.S. Navy now faces a similar situation as the result of the dramatic increase in the numbers and sophistication of anti-ship cruise missiles (ASCMs). The situation is summarized in the 2017 Center for Strategic and Budgetary Assessments (CSBA) fleet architecture study as follows:
“To support deterrence by denial or punishment, American naval forces will need to operate and fight in proximity to the adversary. As described above, U.S. surface forces will face large numbers of enemy anti-ship missiles in these areas and thus require high-capacity air defenses to survive long enough to conduct their offensive missions. Active defenses may, however, be insufficient to win the ‘salvo competition’ between the enemy’s weapons systems and U.S. defenses. To reduce enemy salvos to more manageable levels, U.S. naval forces will also need to deny or degrade the enemy’s ability to find and target ships.”2
The nation that has the offensive capability to suppress an enemy’s intelligence, surveillance, and reconnaissance (ISR) through physical destruction, deception, disruption, and corruption will have the critical edge – that of superior situational awareness, a significantly reduced threat of attack, and the all-important capability to target and attack enemy ships. While one ASCM hit will severely damage or disable most surface ships, anti-ship missiles are a threat only when an enemy ship has been detected, classified and identified, located and tracked, and targeted (e.g. allocated to a land site or an air, surface or subsurface launch platform). This extended kill chain is dominated by information from ISR systems which can be destroyed or disrupted.
To prevail in the salvo competition, the U.S. needs a robust offensive capability for Suppression of Enemy Intelligence, Surveillance, and Reconnaissance (SEISR). Like SEAD, this offensive capability has a preplanned and reactive component. The preplanned component achieves the greatest suppressive effect, but it has to be followed by a reactive component focused on suppression of any remaining or reconstituted ISR capacity. This component can be planned in great detail based on comprehensive intelligence analysis of the adversary’s land, air, space, undersea, and maritime surface ISR capabilities. This includes their associated communications, command and control, and intelligence analytical infrastructures. The reactive component requires current intelligence focused on enemy remaining or reconstituted ISR capabilities in order to plan and execute reactive SEISR operations. The complexity of a near-peer nation’s ISR capabilities suggest that SEISR will require a complex joint service response supported by multiple agencies to achieve the objective of reducing the ASCM threat to levels that are manageable for fleet defenses.
Building on the intelligence foundation, the mission will require an additional level of analysis to identify and assess the wide variety of possible kinetic and non-kinetic options for suppressing the wide range of enemy ISR capabilities. This analysis of suppressive options includes not only the effects of operational capabilities, but also, the identification of opportunities and the definition of requirements for new capabilities. The intelligence and effects analytical capabilities required to support the pre-planned and reactive SEISR missions will require the establishment of dedicated analytical cells that have the depth of knowledge of all aspects of enemy ISR systems and of available kinetic and non- kinetic alternatives for achieving the desired suppressive effects.
Suppression has to include a reactive component focused on suppression of enemy efforts to reconstitute or field new capabilities as the conflict evolves. Like SEAD, after the preplanned options are executed, SEISR will have a strong tactical component that drives a new near real-time intelligence and effects analytical focus, and SEISR capabilities that can be applied without delay when opportunities are presented by the enemy. SEISR will have to be animated by a forward-leaning, tactical mindset to keep up with or anticipate changing enemy ISR capabilities and methods throughout the conflict.
If effective, SEISR will reduce the ASCM threat to levels manageable by fleet non-kinetic and kinetic defenses. The non-kinetic component, often referred to as Counter ISR, will be focused on countering enemy ISR platforms and sensors, and countering launch vehicle and ASCM target acquisition systems. These non-kinetic methods range from tactics such as emissions control (EMCON) to deny detection, deception to confuse, and electronic attack against RF systems. Success is heavily dependent on having technical intelligence on enemy ASCM systems; and, the land, air, surface and subsurface ASCM launch complexes or platforms, and their surveillance, reconnaissance, and target acquisition systems, associated communications, and data links.
The key to tactical success in the defense against ASCM attack is directly dependent on the battlegroup tactical commander and his or her subordinate warfare commanders having the situational awareness that enables them to make better tactical decisions faster than the enemy. This situational awareness will be the result of the automated integration of information that is relevant to the specific commander with respect to geography, content, and timeliness.
SEAD has evolved over the past 70 years. The DoD and Navy do not have 70 years to organize and prepare for conflict against a nation with near-peer ISR and target acquisition capabilities. The SEISR mission will require an institutional focus, the rapid evolution of concepts and tactics, focused intelligence and target study support, and the development of personnel with a tailored commitment to the Counter-ISR missions.
Richard Mosier is a retired defense contractor systems engineer; Naval Flight Officer; OPNAV N2 civilian analyst; OSD SES 4 responsible for oversight of tactical intelligence systems and leadership of major defense analyses on UAVs, Signals Intelligence, and C4ISR.
 Suppression of Enemy Air Defenses — Activity that neutralizes, destroys, or temporarily degrades surface-based enemy air defenses by destructive and/or disruptive means. (JP 1-02)
 Center for Strategic & Budgetary Assessments (CSBA) study, titled Restoring American Seapower: A New Fleet Architecture for the United States Navy , Bryan Clark, Peter Haynes, Jesse Sloman, Timothy Walton, dated 9 February 2017.
Featured Image: PHILIPPINE SEA (June 9, 2019) Marines with Marine Medium Tiltrotor Squadron 265 (Reinforced) aboard the USS Wasp (LHD 1) work on an F-35B Lightning II fighter aircraft during night time flight operations. (Official U.S. Marine Corps photo by Lance Cpl. Kenny Nunez Bigay)