Category Archives: Drones

Development, testing, deployment, and use of drones.

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.

 

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.

What You Can’t Find…

 

Every Drone Can Be a Minesweeper?

A frequently cited fact in my days training to be a naval officer was that the most common weapon for damaging a warship since World War II was the naval mine.  The recently concluded International Mine Countermeasures Exercise 2012 (IMCMEX 12), held in 3 distinct OPAREAs throughout the U.S. Fifth Fleet Area of Responsibility (AOR), demonstrated both the difficulty of mine countermeasures (MCM) operations (detecting and clearing mines) and the potential of new technology to mitigate those dangers.

PBS’ News Hour quotes a retired naval officer and observer of the exercise, Capt. Robert O’Donnell, stating of the 29 simulated mines in the exercise, “I don’t think a great many were found…It was probably around half or less.”

The response from the Navy is a little confusing:

The Navy declined to provide data on how many practice mines were located during the two-week naval drill but did not dispute that less than half were found. However, a spokesman insisted that the figures do not tell the whole story and that the event was “‘not just about finding” the dummy mines.

“We enjoyed great success,” said Cdr. Jason Salata, the top public affairs officer for the 5th Fleet. “Every platform that was sent to find a shape found a shape. We stand by that.” Salata asserted that “there were no missed mines, each platform that had an opportunity to find the mine did so.”

While it is true that a 100% detection rate is not what the exercise was all about, that rate is still an interesting figure.  It could indicate that every mine was found, but perhaps not by every platform – instead as a result of the cumulative MCM effort.  It’s likewise unknown how the success rate broke down by platform and nation – more than 27 international partners operated with U.S. Fifth Fleet as part of the exercise.  What is known is that MCM remains a difficult and deadly business, particularly in the context of some of the most likely future conflict scenarios, including Iran and North Korea. 

While the exercise results will disappoint some (again, we don’t know who or what had difficulty finding what types of mines), they will also serve to reinforce the arguments for recapitalizing the Avenger-class MCMs, outfitting the USS Ponce as an Afloat Forward Staging Base, and placing rigorous demands on getting the LCS MCM mission package right.  As mentioned above, the exercise was additionally an opportunity to test out some new kit.  Before the exercise got underway, NavalDrones provided a preview of some of the Remotely Operated Vehicles (ROVs) and Autonomous Underwater Vehicles (AUVs) slated for testing in the drill, as well as a recap of other drones designed for MCM duties.  Furthermore, a pair of similar threats might spark the development of crossover technology for use in MCM.

In addition to the more traditional types of naval mines, detecting and defeating the waterborne IEDs and enemy drones (AUVs and ROVs) of both state and non-state actors is seen by some as increasing in importance, and may rely on many of the same technologies used in MCM.  Like the land-based IED/counter-IED arms-race of the past decade, we could be witnessing the start of a similar set of opposing innovation escalations.  Foreign Policy earlier this week reported that the creation of the Iraq/Afghanistan wars, the Joint IED Defeat Organization (JIEDDO), is executing its own Pivot to the Pacific to focus on the typically lower-tech threats of waterborne terrorists and IEDs.  Meanwhile NavalDrones last week highlighted some of the detection and clearance technologies that could be used against the evolving undersea drone fleets.  The next decade is shaping up to be an interesting time for technology under the waves.

 

LT Scott Cheney-Peters is a surface warfare officer in the U.S. Navy Reserve and the former editor of Surface Warfare magazine. He is the founding director of the Center for International Maritime Security and holds a master’s degree in National Security and Strategic Studies from the U.S. Naval War College.

 

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 U.S. Department of Defense or the U.S. Navy.