Tag Archives: modularity

Depth from Above: Reinventing Carrier ASW

By Ben DiDonato

With the return of great power competition, the threat posed by hostile submarines has garnered renewed attention. Russia’s submarine fleet in particular has been regarded as a serious threat for decades and its latest SSNs are reportedly nearly as quiet as their American counterparts. Similarly, while China’s nuclear submarines have yet to reach this level, China’s access to Russian technology, rapid improvements in other areas, and capacity for mass production suggest it is likely to become a serious threat in the relatively near future. Furthermore, while SSNs are obviously the most serious threat due to their range and speed, diesel submarines cannot be overlooked, with many highly lethal designs widely distributed across the globe. In order to compete effectively against near-peer states armed with these submarines, the United States Navy must have the ability to find, track, and sink them.

As in the Cold War, anti-submarine warfare (ASW) is a challenging area of operations, requiring close cooperation between a wide variety of assets to win what would inevitably be a worldwide campaign. This problem was thoroughly studied and, at least in broad strokes, solved by the end of the Cold War, so this strategy provides a useful guide. That review immediately reveals a critical weakness in current American force structure. Submarines and maritime patrol aircraft are still available for independent hunting, surface combatants for close screening, and helicopters for prosecuting targets, but since the retirement of the S-3 Viking, the U.S. Navy has lacked an organic aircraft for initial detection of submarines approaching the aircraft carrier.

The current stopgap solution is pressing the land-based P-8 Poseidon into this role, but that is far from ideal. Tying P-8s to carriers largely squanders their capabilities, preventing the limited supply of these aircraft from doing their real job of patrolling broad stretches of ocean and protecting other ships. Furthermore, relying on land-based support imposes serious constraints on the carrier strike group, which must operate within range of the P-8 and would almost certainly suffer from periods of vulnerability.

This means the current lack of fixed-wing carrier-based ASW capability should be addressed to provide the required coverage without distracting the P-8 force. While there has been some discussion of reactivating the S-3 Viking to restore this capability, that can only ever be a stopgap measure due to the age of the airframes. A long-term solution is needed to restore fixed-wing ASW capability, and fiscal reality demands this solution be flexible and affordable. Rather than build a new dedicated ASW aircraft, it may be better to instead develop a series of ASW pods and a more flexible aircraft suitable for both ground attack and ASW since either type of store can be carried on the pylons with equal ease.

Podded ASW Systems

A minimum of four specialized systems are required to support fixed-wing ASW: a Magnetic Anomaly Detector (MAD), a sonobuoy dispenser, a sonobuoy receiver, and an air-droppable lightweight torpedo. The Mk 54 torpedo already meets the offensive needs on other aircraft, so it should not require substantial modification to fill this role. Similarly, a sonobuoy dispenser is such a simple system that it does not require explanation beyond pointing out that it would ideally come in a variety of sizes for different aircraft/pylons and have variants which incorporate a sonobuoy receiver to minimize pylon consumption.

Therefore, the only system which requires major development is the MAD pod. To enable normal aircraft operation, particularly safe takeoff and landing, this pod would almost certainly need to use a towed MAD rather than the more common boom-mounted system. This would allow the sensor to be trailed a sufficient distance behind the aircraft when needed and retracted when not in use.

Of course, this podded approach is also ideally suited to incorporating future systems as they become available. A wide variety of unmanned systems and new weapons are in development or have been proposed, and all of them could easily be integrated as additional pods. Whether new payloads for sonobuoy dispensers, a single large UAV/UUV on a pylon, some new cluster system, or a novel idea not yet conceived, stuffing it in a pod and hanging it from an existing aircraft will always be faster and cheaper than trying to cram it into an existing airframe, assuming that is even possible. Therefore, while this approach provides an easy path for incorporating future technologies, the four proven systems discussed above can be immediately developed into an effective ASW capability and should be the short-term priority.

In order to provide an affordable near-term capability and maximize long-term utility, both the MAD and sonobuoy pods should be compatible with the new MQ-25 Stingray UAV. In conjunction with the current MH-60R, this would provide a limited standoff detection, prosecution, and engagement capability to the carrier which could be further supplemented by F/A-18s carrying torpedoes, MAD pods, and additional sonobuoys to engage submarines if needed. While this combination is certainly suboptimal, especially considering the problems caused by using F/A-18s as tankers, the MQ-25 would truly come into its own as an ASW platform once the new fixed-wing aircraft proposed below enters service and can use it as a loyal wingman to greatly improve coverage or direct MQ-25 wolfpacks to aggressively prosecute contacts.

A Pod-Carrying Aircraft

Unfortunately, this pod-based approach to ASW is fundamentally incompatible with the S-3 airframe. It cannot carry the number and variety of pods or ground attack weapons required on its two underwing hardpoints, especially when we consider future podded systems. Although its weapons bays contain another four hardpoints, their internal placement would likely interfere with the operation of most pods. Remediating this deficiency by adding new pylons in a major refit is likely impractical due to interference from the under-wing engines. The integrated nature of the S-3’s ASW systems also prevents it from using much of its payload capacity for non-ASW missions. It is simply not possible to replace these fixed systems with ground attack or anti-ship weapons when using the aircraft in other roles, leaving it limited to only six weapons hardpoints for these missions.

Shifting to the budgetary side, integrated systems are generally more expensive to maintain and upgrade than podded systems. Furthermore, the Navy presumably lacks the resources to operate both integrated and podded systems, likely costing the carrier air wing the flexibility to task non-ASW aircraft with ASW missions. Budgetary pressures also make this alternate role critical because the S-3 probably would have survived the global war on terror if it doubled as a low-cost ground attack platform. Therefore, long-term use of the S-3 would be costly and inflexible, so a new solution is needed.

The obvious solution is a completely new aircraft. While this is certainly an option and would presumably produce an excellent aircraft with plenty of capacity, numerous pylons, and a low operating cost, there are two major problems with it. The first is that going through the full development and adoption cycle would take a very long time, likely more than could realistically be covered by a stopgap S-3 reactivation. The second is that major projects like this are politically challenging, with a serious risk of cancelation – assuming they get started at all. While it may be possible to overcome these issues, they are serious enough to merit an examination of alternative options.

The most obvious alternative is to adapt an existing carrier aircraft to take on the role. Within the current carrier air wing, there are two possible airframes, the E-2/C-2, and the V-22.

The E-2/C-2 would obviously make an excellent mono-mission platform since it is already configured to carry a large support crew. However, that same large crew would limit its payload and make risking it in other roles like ground attack unappealing. The only other role it could realistically take on is general airborne drone control, but this can already be performed by the E-2 and fighters so there seems to be little value here, especially since these aircraft can also relay drone datalinks to surface ships. While none of this detracts from an E-2/C-2 derivative’s ability to take on the mission, it does mean it fails to realize the additional flexibility promised by this podded approach, so a different platform is preferable.

The V-22, or more accurately the CMV-22B, may be a better candidate. The ability to transition to helicopter mode would be useful for prosecuting targets, and its unsuitability to ground attack is less of an issue since it is already a cargo aircraft, although the flipside of that is that is that there is less leeway to retask between these two missions than between ASW and ground attack. Unfortunately, payload integration may be an issue, both due to questions about retrofitting pylons on the rotating wing assembly and its more limited digital backbone, and overall external stores capacity would likely be limited after the necessary upgrades based on published payload and range figures. Therefore, while it is certainly worth performing a more detailed study to better understand the true costs, capabilities, and limitations of an ASW V-22 variant, it also seems suboptimal for this pod-based approach.

The final alternative is adapting a land-based aircraft for naval service. While there have certainly been serious problems adapting aircraft in the past, there have also been notable successes like the YF-17’s evolution into the F/A-18 family and the SH-60 family’s decent from the Army’s UH-60. Furthermore, the C-130 famously proved able to operate from the USS Forrestal without modification, and based on a recent interview with the pilot, the flying seems to have been fairly straightforward. While the C-130 itself is obviously too big for regular deck handling, this success strongly implies any aircraft designed to operate from short/rough airfields would be an excellent candidate for marinization, especially with a Super Hornet-style redesign.

There are too many aircraft to go through individually, but desired capabilities narrow the field to a smaller slate. The ideal aircraft would be small enough to operate from a carrier, have short/rough field capability, good payload, plenty of pylons, good fuel efficiency, low maintenance requirements, and excellent handling at low speed and altitude. While most aircraft cannot meet this challenging set of desires, there is one candidate suitable for adaptation into a pod-based multirole ASW aircraft. Not only does this aircraft meet all these desires, but it also has an exceptional ground attack record, proven flexibility in other roles like counter-Fast Attack Craft/Fast Inshore Attack Craft (counter-FAC/FIAC) and combat search and rescue support, and, most importantly, very strong political support to carry the program through budget battles. This aircraft is, of course, the A-10.

The SA-10D Seahog

With an A-10 variant identified as the best option for carrying ASW pods, considering both capability and timeline, we now turn our attention to a brief discussion of what that would look like. The most likely approach is a redesign comparable to the Hornet’s “upgrade” to the Super Hornet because that allows any necessary changes to be incorporated relatively easily. That said, the A-10’s unusually simple airframe may allow boneyard aircraft to be modified for service, even if only as prototypes or a wartime contingency, so that possibility will be discussed here as well. Of course, the program office is not obligated to pick just one option. They could develop both a modification package and a new-build design to improve the competition and provide maximum value to the taxpayer.

Since this aircraft will be largely optimized for affordably hauling underwing stores as a byproduct of this pod-based approach to ASW, that payload can be used in a variety of other roles beyond the obvious close air support. This could entail utility duties like backup tanking, combat support roles like standoff missile carrier, and majority Air Force missions like laying Quickstrike sea mines to further support the rest of the air wing, increase the carrier’s flexibility, and improve the lethality of the joint force.

One other intriguing advantage of using the A-10 as a baseline for the ASW pod carrier is that its short/rough field performance suggests it may be possible to fly it from smaller, simpler ships like amphibs, especially if thrust reversers are added. This would give the joint force the ability to rapidly build new ASW hunter-killer groups if needed and could give the Marines an alternate air support option for amphibious operations if desired. Similarly, this would allow commercial ships to be converted into useful escort carriers in wartime, freeing purpose-built carriers for frontline duties. Finally, this would open up the ability to fly from smaller dedicated aircraft carriers and, while it seems unlikely the United States would build any, a number of its allies operate CVLs and may be interested in acquiring these SA-10Ds to provide organic ASW capability and additional strike capacity to their own carriers.

From a programmatic standpoint, using a few minimally modified A-10A’s from the boneyard could serve to reduce risk and accelerate introduction by entering flight testing prior to delivery of the first full prototype, although this is obviously not required. Most usefully, up to three aircraft could be modified to add a second seat for the ASW systems operator and at least simulated electronics to demonstrate operational effectiveness and begin developing tactics and procedures for the fleet ahead of delivery. The other, less important, conversion would validate performance and carrier suitability by adding a new launch bar and a strengthened arresting hook to a single aircraft.

Naturally, the subject of airframe modification entices interest, so we will now move into a brief exploration of the most interesting changes and options, although basics like more modern engines will be omitted. That said, it is critical to bear in mind that this SA-10D concept is fully dependent on the previously discussed podded systems for ASW operations, so those systems are more important than anything discussed here even though this section will likely generate more discussion.

First and most importantly, the aircraft must have a second seat like the old YA-10B prototype. Modern computers should allow a single person to manage all the ASW equipment instead of the multiple operators required on the S-3, as well as direct any supporting drones, but there is no way the pilot would be able to handle that workload on top of flying the aircraft. It should also be noted that this second crewmember can be swapped for another specialist such as a forward air controller when required for the mission at hand, further improving the air wing’s flexibility. Therefore, whether this is a conversion of old airframes or a new build, a single seat is simply unworkable for the mission.

Closely related to this is electronics. To reduce development costs and streamline maintenance, it is strongly recommended that the F-35’s electronics be reused as close to wholesale as possible. The A-10’s simple airframe should make it relatively easy to integrate these systems, especially if it is a new-build variant, and the commonality would bring new capability and simplify future upgrades. Beyond providing a digital backbone to host the ASW systems, this would make the SA-10D a potent networked shooter by hauling large numbers of long-range missiles and seamlessly communicating with F-35Cs further forwards. This could be further exploited by a new-build aircraft which would likely be larger to further increase capacity and could add dedicated AIM-9X sidewinder rails to provide defensive fire against hostile aircraft.

Folding wings would not ordinarily merit separate discussion because it is obvious a new-build aircraft would include them and that the A-10’s straight wings will allow a dramatic width reduction, but the modification of existing airframes is unusual enough to merit special attention. Unlike most aircraft, the A-10 only carries fuel in its inner wing and is designed with very simple, robust structures with extensive left/right interchangeability. This means the A-10 is in the unusual situation of being able to easily accept folding wings in an upgrade, so modified boneyard aircraft are a feasible option even though they were never intended to operate from carriers.

Of course, any time the A-10 comes up, its gun is a major discussion point so it must be addressed here even if it is not relevant to ASW. Unfortunately, while the GAU-8 has given excellent service, it would almost certainly have to be abandoned for marinization in favor of the F-35’s 25mm GAU-22. While the resulting commonality would streamline shipboard logistics, this change is primarily driven by the fact that the GAU-8’s mounting forces the nose wheel off-center on the A-10, which is unacceptable for catapult launch and results in asymmetric turning circles which may complicate deck handling. One potential upside to this change is that it allows an increase in total stowed ammunition and possibly even the installation of a second gun if desired. This could extend the effective range of the weapon by firing enough explosive rounds to effectively saturate the larger dispersion area, potentially allowing the gun(s) to be effective in the counter-FAC/FIAC role from beyond the range of any man-portable air defense systems they may carry.

The A-10’s armor is similarly a regular point of discussion, although in this case there is no clear answer to be had. If old -A models were to be modified for this new role, it would likely prove more practical to simply leave the armor in place even if it is not particularly useful for the aircraft’s new role since it is integrated into the load-bearing structure. Of course, a new build would not face this restriction, so the armor would almost certainly be omitted to save weight. However, modern materials could allow some level of protection to be retained without much of a weight penalty if desired. Ultimately, the details would have to be worked out between the contractors and the program office, so a definitive answer cannot be given here.

One final exotic option for a new-build aircraft is to integrate a laser weapon to shoot down incoming missiles, or at least provide room for one to be added in the future. The technical risks and costs of this are obvious, but with laser weapons entering service and rapidly maturing, it should at least be considered.

Conclusion

As has been shown, the critical vulnerability left by the retirement of the S-3 can be rapidly and affordably filled to ensure the carrier’s survivability against submarines, and by extension its relevance in great power competition or war. A series of podded sensors would allow the MQ-25 and current aircraft to provide some ASW capacity, while a new SA-10D Seahog can be rapidly developed to fully fill the ASW gap using those podded systems and improve the flexibility of the carrier air wing.

Ben DiDonato is a volunteer member of the NRP-funded LMACC team lead by Dr. Shelley Gallup. He originally created what would become the armament for LMACC’s baseline Shrike variant in collaboration with the Naval Postgraduate School in a prior role as a contract engineer for Lockheed Martin Missiles and Fire Control. He has provided systems and mechanical engineering support to organizations across the defense industry from the U.S. Army Communications-Electronics Research, Development and Engineering Center (CERDEC) to Spirit Aerosystems, working on projects for all branches of the armed forces.

Featured Image: An air-to-air front view of three S-3A Viking aircraft from Air Anti-submarine Squadron 31 (VS-31) as they pass over the USS DWIGHT D. EISENHOWER (CVN-69) (Photo by PH3 Houser, via U.S. National Archives)

Print, Plug, and Play Robotics

William Selby is a Marine Officer who previously completed studies at the US Naval Academy and MIT researching robotics. The views and opinions expressed in this article are his own.

In September 1999, NASA lost a $125 million Mars orbiter because a contracted engineering team used English units of measurement while NASA’s team used the metric system for a key spacecraft operation.[i] In everyday life we are forced to choose between differing formats with the same function. What was once VHS vs. Betamax became Blu-ray vs. HD DVD. A lack of component standardization can reduce the operational effectiveness of a system as shown by the NASA orbiter. More commonly, the end user may waste resources purchasing multiple components that serve the same purpose, as was the case for DVD players in the late 2000s. These same issues are occurring in the development, procurement, and operation of our unmanned systems. Over the last decade, the US military has amassed large numbers of unmanned systems composed of highly proprietary hardware and software components. However, future unmanned systems designed with interoperable hardware and software and constructed utilizing advanced manufacturing techniques will operate more effectively and efficiently than today’s platforms.

 

Advances in manufacturing techniques as well as efforts to standardize software and hardware development are being pursued in order to diminish the negative effects caused by proprietary components in unmanned systems. These new technologies focus on speed and customization, creating a new and evolving research, development, and production methodology. Modular designs increase the rate of production and upgrades while new manufacturing techniques enable rapid prototyping and fabrication on the front lines. Replacement parts can be stored digitally, produced on demand, and swapped between unmanned systems, reducing the system’s logistical footprint. This organic production capability will enable units to tailor manufacturing needs to match operational requirements. The resulting unmanned systems will operate with interchangeable payloads making them quick to adapt to a dynamic environment while common software will enable easier control of the vehicles and wider data dissemination.

 

Complementary Technologies

 

The concept of interoperable hardware and software is more formally referred to as open architecture (OA). DOD Directive 5000.1, “The Defense Acquisition System,” outlines the DOD’s goal to acquire systems that can be easily swapped between unmanned systems similar to the way different types of USB devices can be swapped out on a personal computer. [ii] This ranges from swapping sensor payloads between platforms to entire unmanned systems between services and countries.[iii] Establishing standards and creating policy for OA are the responsibilities of multiple organizations. For unmanned aerial systems (UASs), the Interoperability Integrated Product Team (I-IPT) drafts UAS System Interoperability Profiles (USIPs). Similarly, the Robotic Systems Joint Program Office (RS JPO) creates Interoperability Profiles (IOPs) to identify and define interoperability standards for unmanned ground systems. Several of the IOP standards have been adopted for unmanned maritime systems by the Naval Undersea Warfare Center.[iv]

 

Advances in manufacturing techniques complement and leverage the OA concept. In general, these techniques focus on converting a digital blueprint of a component into its physical form. The advantages of additive manufacturing, commonly known as 3D printing, have been recently publicized as well as potential military applications.[v],[vi],[vii],[viii] 3D printing creates the desired object in metal or plastic by converting liquid or powdered raw materials into a thin solid layer, forming a single layer at a time until the piece is completed. Less mature technologies include Printed Circuit Microelectromechanical Systems (PC-MEMS) uses 3D printing to create a flat object of rigid and flexible materials with special joints that are later activated turning the flat object into a three-dimensional object much like a children’s pop up book. [ix],[x] A final technique inspired by origami involves etching crease patterns into flat sheets of metal allowing them to be quickly folded and assembled into complex components. [xi]

 

Lifecycle Impacts

 

Production of future unmanned systems will be altered by these technologies beginning with the initial system requirements.[xii] Standard capability descriptors minimize the need for a single, large business to create and entire unmanned system. This will allow small businesses to focus research and development on a single capability that can be integrated into multiple platforms requiring that capability thereby increasing competition and innovation while reducing initial procurement costs.[xiii],[xiv] These unmanned systems will be easily upgradeable since payloads, sensors, and software are anticipated to evolve much faster than the base platforms.[xv] Open hardware and software ensures that upgrades can be designed knowing the component will function successfully across multiple platforms. Advanced manufacturing techniques will enhance the development of these upgrades by allowing companies to rapidly prototype system components for immediate testing and modification. Companies can digitally simulate their component to verify their design before mass producing a final version with more cost effective traditional manufacturing techniques. The final version can then be digitally distributed enabling the end user to quickly load the most recent version before production.

 

These technologies also have the potential to significantly impact supply chain management and maintenance procedures required for unmanned systems. Since components can be swapped across multiple platforms, it will no longer be necessary to maintain independent stocks of proprietary components unique to each platform. If a component can be created using organic advanced manufacturing techniques, only the digital blueprint and raw materials need to be available. While the strength of components created using additive manufacturing may not be enough for a permanent replacement, temporary spare parts can be created in a remote area without quick access to supplies or depot repair facilities while permanent replacements are delivered. This reduces the logistical footprint and maintenance costs by limiting the number of parts and raw materials required to be physically stored for each system.

 

Most importantly, these technologies will produce unmanned systems with the operational flexibility necessary for the unknown conflicts of the future. Components ranging from power systems to sensor payloads can be quickly and easily swapped between platforms of varying vendors, selected to fit the mission requirements and replaced as the situation develops.[xvi]Standardizing the sensor’s data transmission format and metadata will generate timely and accurate data that is more easily accessed and navigated by all interested parties.[xvii] An early example of these advancements, the Army’s One System Remote Video Terminal, allows the user to receive real time video footage from multiple platform types as well as control the sensor payload.[xviii],[xix] Digital libraries will close the gap between developer and user ensuring the most recent component design is manufactured or the latest software capability is downloaded and transferred across platforms.[xx] Standardized communications protocols between the platform and the controller will enable a single controller to operate different platforms, as recently demonstrated by the Office of Naval Research.[xxi] Further into the future, the operator may be able to control multiple unmanned systems across various domain simultaneously.[xxii],[xxiii] The ability to create heterogeneous “swarms” of unmanned systems with varying sensor suites in different physical operating environments will give the commander the flexibility to quickly configure and re-configure the unmanned system support throughout the duration of the operation.

 

New Technologies Create New Vulnerabilities

 

As these technologies are implemented, it is important to keep in mind their unique limitations and vulnerabilities. The stringent qualification process for military components, especially those with the potential to harm someone, is often described a key limitation to the implementation of modular components.[xxiv] However, without people on board, unmanned systems have lower safety standards making it easier to implement modular components in final designs. Compared to traditional methods, additive manufacturing is slow and produces parts limited in size. The materials have limited strength and can be 50 to 100 times more expensive than materials used in traditional methods.[xxv] While future development will decrease prices and increase material strength, traditional manufacturing techniques will remain more cost effective means of producing high volume items into the near future. Additionally, open designs and digital storage can create vulnerabilities that may be exploited if not properly secured. Militants in Iraq purportedly viewed live video feeds from UASs using cheap commercial software while Chinese cyberspies allegedly gained access to many of the US’s advanced weapons systems designs.[xxvi],[xxvii] Further, digital blueprints of parts have the potential to be modified by nefarious actors to create counterfeit or falsified parts.[xxviii] As the price of manufacturing equipment quickly drops, anyone can create the products when given access to the digital copies.[xxix]

 

Future technological innovations have the ability to modify traditional supply methodologies allowing the end user to manufacture parts on demand for use in a variety of unmanned systems. Proprietary hardware and software can be minimized, resulting in unmanned systems with smaller logistical footprints condensing vulnerable supply chains while reducing overall system cost. These benefits are tempered by the unique vulnerabilities that arise when standardizing and digitizing unmanned system designs. Despite these potential vulnerabilities, the ability to equip a force with increased capability while reducing costs and logistical requirements is indispensable. While the locations of the next conflicts will remain hard to predict, unmanned systems able to complete a variety of missions in remote areas with limited logistical support will become an operational necessity.

 

[i] Lloyd, Robin, Metric mishap caused loss of NASA orbiter, accessed athttp://www.cnn.com/TECH/space/9909/30/mars.metric.02/index.html?_s=PM:TECH, 30 September 1999.

[ii] U.S. Department of Defense, DOD Directive 5000.1 – The Defense Acquisition System, Washington D.C., 12 May 2003.

[iii] U.S. Department of Defense, Unmanned Systems Integrated Roadmap FY2013-2038, Washington D.C., 2013.

[iv] U.S. Department of Defense, Unmanned Systems Integrated Roadmap FY2013-2038, Washington D.C., 2013.

[v] Llenza, Michael, “Print when ready, Gridley,” Armed Forces Journal, May 2013.

[vi] Beckhusen, Robert, Need Ships? Try a 3-D Printed Navy, accessed at http://www.wired.com/dangerroom/2013/04/3d-printed-navy/, 04 May 2013.

[vii] Cheney-Peters, Scott and Matthew Hipple, “Print Me a Cruiser!” USNI Proceedings, vol. 139, April 2013.

[viii] Beckhusen, Robert, In Tomorrow’s Wars, Battles Will Be Fought With a 3-D Printer, accessed at http://www.wired.com/dangerroom/2013/05/military-3d-printers/, 17 May 2013.

[ix] Leung, Isaac, All abuzz over small pop-up machines with Printed Circuit MEMS, accessed at http://www.electronicsnews.com.au/news/all-abuzz-over-small-pop-up-machines-with-printed-, 22 February 2012.

[x] Wood, R.J., “The First Takeoff of a Biologically Inspired At-Scale Robotic Insect,” Robotics, IEEE Transactions on , vol.24, no.2, pp.341,347, April 2008.

[xi] Soltero, D.E.; Julian, B.J.; Onal, C.D.; Rus, D., “A lightweight modular 12-DOF print-and-fold hexapod,” Intelligent Robots and Systems (IROS), 2013 IEEE/RSJ International Conference on , vol., no., pp.1465,1471, 3-7 Nov. 2013.

[xii] U.S. Department of Defense, Unmanned Systems Integrated Roadmap FY2011-2036, Washington D.C., 18 September 2012.

[xiii] Real-Time Innovations, Interoperable Open Architecture, accessed at

http://www.rti.com/industries/open-architecture.html, 2012.

[xiv] U.S. Department of Defense, Unmanned Systems Integrated Roadmap FY2013-2038, Washington D.C., 2013.

[xv] U.S. Department of Defense, Unmanned Systems Integrated Roadmap FY2013-2038, Washington D.C., 2013.

[xvi] Real-Time Innovations, Interoperable Open Architecture, accessed at

http://www.rti.com/industries/open-architecture.html, 2012.

[xvii] Crawford, Katherine, ONR Provides Blueprint for Controlling All Military Unmanned Systems, accessed at http://www.onr.navy.mil/Media-Center/Press-Releases/2013/ONR-Provides-Blueprint-for-Controlling-UAVs.aspx, 01 May 2013.

[xviii] Shelton, Marty, Manned Unmanned Systems Integration: Mission accomplished, accessed at http://www.army.mil/article/67838, 24 October 2011.

[xix] AAI Corporation, One System Remote Video Terminal, accessed at https://www.aaicorp.com/sites/default/files/datasheets/OSRVT_07-14-11u.pdf, 14 July 2011.

[xx] Lundquist, Edward, DoD’s Systems Control Services (UAS) developing standards, common control systems for UAVs, accessed at GSNMagazine.com, 06 January 2014.

[xxi] Crawford, Katherine, ONR Provides Blueprint for Controlling All Military Unmanned Systems, accessed at http://www.onr.navy.mil/Media-Center/Press-Releases/2013/ONR-Provides-Blueprint-for-Controlling-UAVs.aspx, 01 May 2013.

[xxii] DreamHammer goes Ballista for multi-vehicle control software, Unmanned Daily News, 15 August 2013.

[xxiii] SPAWAR Systems Center San Diego, Multi-robot Operator Control Unit (MOCU), accessed at http://www.public.navy.mil/spawar/Pacific/Robotics/Pages/MOCU.aspx.

[xxiv] Freedberg, Sydney J., Navy Warship Is Taking 3D Printer To Sea; Don’t Expect A Revolution, accessed at http://breakingdefense.com, April 2014.

[xxv] McKinsey Global Institute, Disruptive technologies: Advances that will transform life, business, and the global economy, accessed at http://www.mckinsey.com/insights/business_technology/disruptive_technologies, May 2013.

[xxvi] Gorman, Siobhan, Yochi Dreazen, and August Cole, Insurgents Hack U.S. Drones, The Wall Street Journal, 17 December 2009.

[xxvii] Nakashima, Ellen, Confidential report lists U.S. weapons system designs compromised by Chinese cyberspies, The Washington Post, 27 May 2013.

[xxviii] NexTech, Project Summary, NOETICGROUP.COM, April 2012.

[xxix] Llenza, Michael, “Print when ready, Grindley”, Armed Forces Journal, May 2013.