Tag Archives: UAVs

Drones of the Navy SEALs

ScanEagle Launched from Mk V SOC
ScanEagle Launched from Mk V SOC

The mystique of Navy SEALs has been heavily celebrated in the media and films due to recent real-world exploits.  Yet Naval Special Warfare (NSW) Sailors have been heavily engaged in combat operations for more than 11 consecutive years.  Warfare is still a decidedly human endeavor, and America’s naval special warriors are quick to embrace the truth that “humans are more important than hardware.”  Nevertheless, today’s SEALs, Special Warfare Combat Crewmen, and other supporting personnel in the NSW community have benefited greatly from technology, which increasingly includes unmanned systems.

Two primary realizations within the NSW community drove the rapid introduction of UAVs for combat operations in Southwest and Central Asia.  The first realization was that even the best shooters in the world are ineffective if they are unable to locate their targets.  Simply, UAVs are a force multiplier for SEALs and enable an exponential increase in their ability to find, fix, and finish targets.  Secondly, as more and more small UAVs were added to the force, NSW began to understand that as valuable as these unmanned systems were, the skills required to operate and maintain them were a distraction for highly trained shooters.  This epiphany led to the creation of Unmanned Aircraft Systems Troops at Naval Special Warfare Support Activity (SUPACT) One in Coronado, California, and SUPACT Two at what is now Joint Expeditionary Base Little Creek-Fort Story, Virginia.  According to Naval Special Warfare Command, each UAS Troop totals 35 personnel among three detachments of UAS operators, a group of instructors, and military and civilian maintenance technicians.

For some additional first-person historical perspective on the evolution of unmanned air systems (UAS) in NSW, former Navy SEAL UAS expert and current lighter-than-air unmanned systems entrepreneur John Surmount discusses the origins of unmanned air systems in Naval Special Warfare in Operation Enduring Freedom in this podcast.  Since those early days, the breadth and depth of unmanned systems used by Naval Special Warfare Operators has expanded tremendously.

The exact tactics, techniques, and procedures for UAS use with NSW are a closely guarded secret (as well they should be), but in general, SEALs use drones to support the four core missions of NSW:

  • Direct Action (DA) – offensive missions to capture/kill enemy targets
  • Special Reconaissance (SR) – surveillance and monitoring of enemy activity and the littoral environment including beaches and ports
  • Counter-terrorism (CT) – conducting DA against terrorist networks
  • Foreign Internal Defense (FID) – assisting foreign military partners in developing their own special operations capacity.

UAVs are especially critical for finding and fixing the exact location of an enemy in DA and CT.  They also support, and in some cases replace, the eyes of operators in SR missions.  On a micro-scale, a demonstration the utility of UAVs can be seen in the film “Act of Valor” where a Raven UAV – launched by actual operators from Special Boat Team 22 – provides ISR over-watch of SEAL operators on a mission.  A more-capable, marinized UAV, the Puma AE, is also part of NSW’s inventory.

The beauty of these rucksack-portable systems is that they can provide organic support to a platoon or smaller-size group of SEALs.  The primary drawback is limited endurance.  Enter the Small Tactical UAS (STUAS).   NSW has embraced the ScanEagle for missions where long endurance ISR is a requirement.  NSW ScanEagles can be sea-launched from vessels as small as a MK V Special Operations Craft or based ashore at expeditionary sites.  Another example of the value of UAVs in the over-watch role was demonstrated in April 2009, when a ScanEagle provided a real time feed to assist SEALs in rescuing the Maersk Alabama’s Captain Richard Phillips from his pirate captors.   

More recently, NSW has benefited from the Navy’s introduction of the shipboard vertical take-off and landing (VTOL) Fire Scout.  Requirements for the next-generation VTOL UAS, the Fire-X MQ-8C, are also driven by special operations forces.  Future developments in Navy UAS integration for NSW will undoubtedly include armed tactical UAVs providing fire support to operators on the ground and sea.

The same concept of ISR support and armed over-watch applies to more complex operations with larger UAVs.  Land-based Air Force Predator and Reapers support NSW missions in Afghanistan and other areas.  A low-signature RQ-170 drone reportedly assisted the SEALs who conducted the raid to kill Usama bin Laden in May 2011.  NSW is also slowly progressing in the implementation of unmanned undersea vehicles (UUV).  These systems are used for missions such as hydrographic reconnaissance reducing the risk to operators and letting them focus on other core missions.  Much as the Navy’s Explosive Ordnance community has embraced autonomous underwater vehicles to help them hunt and neutralize mines, SEALs will eventually find themselves reliant on robots to survey beach landing sites.

Along with other underwater assets such as swimmer delivery vehicles, UUVs fall under the auspices of Naval Special Warfare Group Three (NSWG-3).  In 2010, Naval Special Warfare Command ordered some Iver2 autonomous undersea vehicles for experimentation.  NSW has also purchased 18 Semi-autonomous Hydrographic Reconnaissance Vehicles (SAHRV) outfitted with side-scan sonar and an Acoustic Doppler Current Profiler.  SAHRV is an adaptation of the REMUS 100.  On the USV side, earlier this year, Naval Sea Systems Command’s Naval Special Warfare Program Office sponsored a test of a Protector USV armed with Spike missiles.  The application of such a capability in support of NSW missions is unclear.

The combination of the world’s most proficient naval special operators enhanced by modern technology will continue to produce powerful strategic effects through tactical actions.


This article was re-posted by permission from, and appeared in its original form at NavalDrones.com.

On the Wings of the Sun? Harnessing Solar Power for Aviation

Solar Impulse HB-SIA in flight
         It may be a little gangly, but that’s just a sign of growth spurts

A few months back we had a guest post from NavalDrones on the site discussing power needs for drones, focusing on the advantages of batteries compared to today’s combustion engines. Engines are noisy, limiting drones’ stealthiness, and both engines and batteries require refueling/recharging. Thus, lengthy, days-long on-station operations aren’t in the cards for today’s drones. (For example, the Global Hawk can fly continuously for about 28 hours.) A balloon or dirigible could stay aloft for longer periods, but at the expense of maneuverability and speed. For reasons like these, harvesting solar power during flight has captured the attention of many aerospace engineers.

One challenge terrestrial solar-powered vehicles face is the variability of cloud cover. In contrast with its grounded brethren, solar aircraft can often negate a cloudy day by just climbing to a sufficient altitude. However, night is, of course, still an obstacle to long-term flight (or short-term missions not in the daytime).

Nevertheless, with the aid of batteries, today’s solar drones and UAVs can fly non-stop for weeks. The British-US aerospace and defense company QinetiQ developed the drone Zephyr, which stayed aloft for 14 days in July 2010 (h/t to Solar Impulse). Zephyr is not small (12-m [39-ft] wingspan), as one can see in the following video, but it is light—only 27 kg, or ~60 lbs, hence the hand-launch. It reached an altitude of 21.6 km (13.4 mi) on that first flight, boosting its observational capabilities.


[youtube http://www.youtube.com/watch?v=ejXaAwsIDoI&w=560&h=315]

Meanwhile, the goals of the Solar Impulse team might be even more audacious: a solar-powered flight around the world in 2015— with a pilot. While it’s perhaps not the most agile, the HB-SIA has already demonstrated 24-hr flight in the past year (with a battery system) from Switzerland to Morocco. And the team has strong backing; it was launched by Bertrand Piccard, who made his name in aviation by circumnavigating the world in the Breitling Orbiter balloon in 1999. Industrial partners include Solvay, Décision, and Bayer MaterialScience, who increased their funding for the project in October [h/t to Flightglobal]. In contrast to Zephyr, HB-SIA’s mass is 1600 kg (3500 lb), about as much as a car, and its 63-m (208-ft) wingspan is about 60% longer than Global Hawk’s – necessary to fit enough solar cells to lift that mass.

So what’s next for solar aircraft? A higher-density storage system than batteries would help by extending flight time. NASA tested a series of solar UAVs in the early ’00s, including Helios, which included an “experimental fuel cell system” that used solar power to regenerate its fuel, storing more energy per pound than batteries. Unfortunately, a crash in 2003 destroyed Helios, but a fuel-cell system remains a possible avenue of advancement. Surface-based lasers can also offer additional illumination for a power boost (also covered in Naval Drones’ post).

Increasing the efficiency of solar cells is another route. Aircraft using solar cells require large wings whose size and shape are driven in part by demands for enough surface area to power the aircraft. These designs limit maneuverability and high-performance (i.e. high-power-demand) attributes like sudden acceleration and changes in direction. Unfortunately, physics principles constrain just how much efficiency can increase. Solar Impulse uses cells with an efficiency of 22.7% — higher than most commercial modules in solar farms. But using only one kind of material in the cell to absorb light means it can harvest only part of the sun’s light, at maximum about 33% (something called the Shockley-Quiesser limit).

Multi-junction cells can capture more slices of the solar spectrum, but in practice their complex assembly limits them to two or three absorber materials. So far they are mostly used in spaceflight, where low weight is a bigger driver than low cost. Still, according to the U.S. National Renewable Energy Lab, the record triple-junction cell (without concentrators, which are another topic) has 35.8% efficiency. So assuming for the sake of estimation that these triple-junction cells weigh about the same per unit surface area (not true at present, according to Solar Impulse), they could reduce wing area by about 37%.  Or, depending on the requirements, they could produce 58% more power.

And power is the big difference between a solar airplane like HB-SIA and a fuel-burner like Global Hawk. HB-SIA’s electric engines produce a maximum of 30 kW (40 hp), whereas Global Hawk’s engine produces at peak 7600 lbs of thrust at a top speed of 357 mph, which works out to 5.4 MW (7200 hp). In part we could say that HB-SIA is more efficient, so it doesn’t need as much power, but on the other hand, Global Hawk can carry a 1360-kg (3000-lb) payload, whereas HB-SIA can carry… one human.

Doing the math shows the upper limit of improving power capture. The sun provides, at midday, 1.3 hp per square meter (of land surface). This handy figure gives you an idea of the maximum solar power wings of a given size could produce (with magical 100% efficient cells). Thus, performance improvements may come from vehicle lightweighting, rather than ratcheting up solar cell efficiency. For example, batteries make up one-quarter the total mass of HB-SIA (400 kg, or 800 lb). And while modern aircraft bodies are increasingly made of carbon fiber (instead of aluminum), companies such as Nanocomp and TE Connectivity are also beginning to manufacture data and power cables made of carbon nanotubes (CNTs) on the scale of miles. CNTs can match the conductivity of copper while saving ~70% of the weight.

Even if it doesn’t displace the combustion-engine in aviation when speed and heavy lift are required, solar power’s promise of nearly indefinite sustained flight is likely to expand its role in aeronautics in the near future.

Dr. Joel Abrahamson holds a PhD in chemical engineering from the Massachusetts Institute of Technology (MIT), where he created nanomaterials for lightweight, high-power electricity generators. He currently researches materials for thin-film, flexible solar cells at the University of Minnesota. The opinions and views expressed in this post are his alone and are presented in his personal capacity. They do not necessarily represent the views of the University of Minnesota.

Armed USVs: A Deeper Dive

The U.S. Navy’s recent testing of a Protector unmanned surface vessel (USV) with the Precision Engagement Module (PEM) weapons system warrants deeper analysis than provided by news reporting.  The project is sponsored by the Chief of Naval Operation’s Expeditionary Warfare Division (N95) and the Naval Sea Systems Command’s Naval Special Warfare Program Office.  To understand the ramifications of this testing, it’s worthwhile to elaborate a bit on the components that make up the PEW:

Protector USV – The U.S. Navy’s Protector is a joint development between Israel’s Rafael, BAE Systems, and Lockeed Martin.  Originally conceived as a platform for force protection and port security, the 11 meter vessel’s new armament opens up a range of possibilities for future employment (discussed below).  Much like a UAV, the Protector requires two operators based ashore or at sea; one to drive the vessel and the other to operate the sensors and armament.

Toplite EOS  The Protector’s Electro-Optical Surveillance, Observation, and Targeting System consists of a four-axis gimbal stabilized turret housing a FLIR, low-light television camera, an eye-safe Laser Range Finder (LRF), and a Night Vision Imaging System (NVIS) compatible, laser target illuminator.  The system interfaces to the USV’s radar, navigation systems (Inertial Navigation System and GPS), and the MK 49 weapons mount. 

MK 49 Mod 0  – Based on the mini-Typhoon family of lightweight, stabilized, remote-controlled weapons mounts, the MK 49 is a joint venture between Rafael and General Dynamics.  The Navy’s MK 49 features a .50 caliber machine gun in addition to the dual-missile pod.  A larger version of the Typhoon forms the basis of the Navy’s Mk 38 Mod 2, 25 mm remotely operated chain guns currently installed on several classes of warships.

Spike LR – The 13 kg fire-and-forget weapon is derived from Rafael’s original Spike anti-armor weapon.  The Spike missile uses electro-optic and infrared sensors to identify and lock onto the target.  The missile can be guided en route to the target by a thin fiber optic tether that is spooled up and uncoils automatically during flight, providing the operator with a real-time first person view.  The Spike’s 4 kilometer range and tandem warhead makes it effective against moving or stationary targets at sea or ashore, including boats and armored vehicles.  Six Spikes were fired on October 24, all of them hitting their target. 

How could such a platform be employed tactically?  In a counter-swarm scenario, a GEN I Mothership would deploy with four to six Protectors in the well deck.  Operating in conjunction with UAVs, helicopters, or maritime patrol aircraft, the Protectors would be cued towards a group of enemy fast attack craft (FAC) or fast inshore attack craft (FIAC).  When the appropriate engagement criteria were met, the USV would launch its salvo of two SPIKE missiles into the enemy swarm, leaving “leakers” for armed UAS, helos, or a ship’s defensive weapons.  Other perturbations of this scenario involve the use of USVs to draw a manned boat swarm away from high value units, or towards an airborne ambush.  Similar to the way UAVs are operated, the USVs would patrol in 24 hour “orbits” each watching a sector oriented to a potential threat (such as a known FAC/FIAC operating base).  The USVs would also screen high value units (carriers, lightly armed supply ships, etc.) during strait or chokepoint transits.

Another way this type of compact weapons system could be employed is to provide economical, rapidly deployable anti-surface firepower in an inland sea or riverine environment.  As an example, the oil rich Caspian Sea is currently undergoing somewhat of a naval arms race, with Iran, Turkmenistan, and Kazakhstan all adding bases and warships there.  The ability of the U.S. Navy to engage in that environment is limited, but flying in armed USVs to a near-by friendly base would provide at least a minimal anti-surface surveillance and engagement capability.  The craft could even be modified for air-drop, like the similarly sized 11 meter RHIB Maritime Craft Aerial Deployment System (MCADS) in use with the Navy’s Special Boat Teams.

With additional autonomous features, a USV like the Protector could perform as a lethal autonomous robot (LAR). Jeffrey S. Thurnher argues that the pace of future warfare against threats such as Iranian boat swarms warrants the speed enabled by autonomous decision making in USVs. Although the Protector uses Rafael’s Lightlink jam-resistant communications system, in a future conflict, adversary jamming and cyber-attack capabilities will require drones to autonomously identify, track, and target enemy vessels without the interface of a manned operator.

The PEM testing follows the Navy’s recent trend of providing additional firepower to existing surface ships. In addition to the above-mentioned MK 38 chain gun serving across the fleet, the Navy’s Patrol Coastal class currently operating in the Persian Gulf will soon be fitted with the Griffin short-ranged missiles. These improvements indicate a degree of urgency in preparing for the counter-swarm mission.   According to NAVSEA, the “USV PEM project was developed in response to recent world events involving swarms of small attack craft, as well as threat assessments outlined in recent studies conducted by the Naval Warfare Development Command.”

This article cross-posted with permission from NavalDrones.com.

Dual-Use Drone Swarms


Weaponizing individual drones is just the beginning…

By Chris Rawley

Last winter over at Information Dissemination, I made the observation that swarming robots will irreversibly transform warfare, and I hold to that argument.  The discussion and progress in this area is developing quickly.  Much of this conversation involves non-military uses for drone technology, but as with many tools, there are also applications for warfare.  A host of militarily useful scenarios can be envisioned to employ very small unmanned naval platforms in a non-lethal fashion.

In the videos below, quadrotors are used to perform simple construction tasks. The technology that is today viewed as modern performance art could some day be utilized to build an expeditionary forward operating base remotely.  A C-130 would fly over a likely FOB site and deploy hundreds of UAVs, which would quickly go to work filling Hesco Barriers and building fighting positions all night long based on a pre-programmed design, a scoop of sand at a time.  Out of power, the drones could then land on the FOB and relay observations to the incoming troops. The site would be defensible as soon as the first Marines arrived, leaving Sea Bees for more valuable construction projects.


Researchers in the UK are developing autonomous vehicles which will replace the tedious role of scuba divers who painstakingly seed damaged coral reefs.  The alternative being worked is to allow “multiple small autonomous robots following a simple set of rules and seeking out coral fragments and re-cementing them to the reef.  But first the robot needs to be driven by a computer ‘trained’ to recognise coral fragments from other objects such as rocks, litter, sponges and other sea creatures… The swarm of autonomous underwater robots will operate according to a simple set of ‘micro-rules’ to seek out coral fragments and re-cement them to the reef.”

A swarm of nano-UUVs similarly equipped as the “coralbots” could quietly infiltrate an enemy naval port and use sensors and algorithms to recognize seawater intakes on ships.  These intakes are indispensable on just about every vessel and are used for heat exchangers cooling engines and various pumps, to make fresh water for the crew, and to propel water-jet equipped ships like the LCS.  The UUVs could inject a combination of mud or sand scooped up from the harbor with epoxy into these intakes, effectively rendering the fleet useless and unable to get underway.  A similar attack could gunk up the intakes to power plants, refineries, and other coastal infrastructure.


The idea of drones mimicking insects might have other applications.  Like bees or fire ants who can subdue a much larger predator, disposable micro-UAVs – too small to defeat with CIWS or other weapons systems – might swarm an Aegis combatant, each spraying a tiny amount of radar absorbent paint on the SPY array, achieving a mission kill of the most powerful air and missile defense system in the world. 

Of course, these sorts of aerial swarms might be vulnerable to jamming, EMP, and the like, but here, LT Matt Hipple offers some recommendations to build resiliency into drone swarms.  The rapid evolution of drone swarm technology can be expected to continue until concepts like these are deployed operationally; likely sometime in the next decade.

This article was re-posted by permission from NavalDrones.com