Throw-aways that come back.

Hand-launched drones have been used far over-the-hill surveillance since the mid-1980s. And the maturation of mini- and micro-electronic technologies has helped to fill the backpacks of infantry units at a frightening pace. Today, armed with what could pass as a model plane and a laptop computer, forward operating soldiers are being treated to a new view of the battlefield.

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Black Widow, Pointer, Hornet and Snake Eye are not names that readily bring to mind something one would purposely carry in a backpack, but these are the new eyes of the battlefield for ground units.

The operational capabilities of Unmanned Aerial Vehicles, or UAVs, have been brought to light by recent conflicts in the Middle East and Afghanistan, where the now combat proven Predator, Global Hawk and the, at one time ubiquitous, Gnat 750 have reigned as supreme battlefield overview commanders. Yet little mention has been made of the small and very effective mini and micro hand-launched variants operated by the foot soldier.

These Micro or Mini UAVs (MAV)--small versions of the larger drones, offer real-time reconnaissance and surveillance imagery in areas that are either not immediately reachable by the ground soldier, are considered hostile or are too distant from the organic unit to provide up-to-date surveillance data.

First of Class

One of the first mini systems in use with the US Army was the Aerovironment Pointer. Initially developed in 1986 and delivered to the Army in 1988, the 3.75 kg air vehicle was designed as an innovative concept in backpack-carried, electric motor powered, hand-launched aerial surveillance vehicles. The airframe has over time suffered few design upgrades, but due to the miniaturisation of electronics and the emergence of payload types the system's weight has wavered--rising to as much as 4.5 kg at one time.

Upon dissecting the Pointer as a hand-launched system example, one finds the air vehicle carried in two containers and the Ground Control Station (GCS) arriving in a briefcase that fits into a standard infantryman's M.O.L.L.E. pack. The air vehicle is of a Kevlar composite at 1.8-metres long with a 2.7-metre wingspan, and the electric-powered GCS weighs less than eight kg. One soldier can operate the entire system, but with hundreds of units having been sold to US forces, a typical set-up has emerged where two users--one pilot and one mission operator--has become standard practice.

Momentarily continuing with the Pointer system, operation is by performing quick pre-flight checks, then literally tossing the unit into the air and returning to the GCS. The air vehicle will follow pre-programmed waypoints or can be operated manually. Upon landing the Pointer performs a deep stall and falls vertically, retaining its equilibrium to the land softly.

Thus far, some 60 Pointer systems have been purchased by the US military Special Operations Command (Socom), and Socom procurement officials have revealed that deployed Special Forces operators are "screaming for more".

One interesting feature of the Pointer is its fixed-view, forward-looking camera, of which either a colour daylight or infrared/thermal type may be used. This puts the pilot in the position of the nose of the bird and is in stark contrast to the Skylark system from Israel's Elbit Systems, who has recently released that an undeclared number are currently in low-rate initial production for the Israel Defense Forces.

The Skylark (this article's lead image) features a fully-gimballed and stabilised camera mount. This freedom of movement allows the operator to track a target in a lock-on mode regardless of the flight pattern of the bird.

Another surveillance feature of the Skylark is its 'follow-camera' mode, whereby the pilot operates the camera only, whilst the UAV automatically flies in a software-defined pattern or direction that will provide the best position for viewing the target.

Elbit Systems comes to the UAV table with myriad experience from its Hermes trio of unmanned systems. The company had earlier developed another handlaunched system for the Israel Ministry of Defense, the Boomerang, through one of the Elbit's subsidiaries, though the project was put to pasture due to the increased interest in the Skylark.

The Skylark system contains three air vehicles and a Mini Ground Control Unit (MGCU) all carried in two backpacks; it is deployable in less than ten minutes and operated by a team of two. Launching is achieved through the use of a bungee-type elastic chord and recovery is through a pre-programmed automatic system that brings the air vehicle within five metres of the operator (the MGCU, actually), then puts it into a deep stall which actuates an airbag that cushions the bird's impact.

The Skylark will automatically increase its altitude if the line-of-sight datalink signal is lost and, if no data signal is reconfirmed, will return to its pre-programmed landing point.

Skylark is apparently a popular name. as Rafael, also of Israel, has produced its own man-portable mini Skylark, but in a tube-launched version. The six-kg retrievable aircraft is twelve cm in diameter and features foldout wings that are snapped into position by a tiny electric motor shortly after launch. The drone is equipped with a stabilised camera that provides wide-area coverage and point-of-interest monitoring, and it can loiter for more than one hour in a ten-km radius from its launch point.

Flight tests of Rafael's Skylark were conducted in February 2004 that included successful tube launches, the drone following pre-programmed mission way-points and effecting a textbook landing at a pre-arranged retrieval point.

Tube launching has an added advantage in its ability to be fired in spaces where getting a running start is not possible.

Non-foldable Road Map

Autonomous flight, auto take-off and landing, waypoint following are impossible features without some means of position tracking and an autopilot system.

One Canadian company, MicroPilot, is firmly entrenched in the autopilot arena. Founded in 1995 and having produced its first product as late as 2000, MicroPilot hardware is to be found on a variety of UAVs, including BAI Aerosystem's Snake Eye (a Dragon Eye variant), the X-Vision and Scrab from Spain's Sistemas de Control Remoto, the HeliSpy VTOL air vehicle and both the Inventus S-1 and E drones from Lew Aerospace.

The most recent of MicroPilot's auto-pilot systems is the [MP2028.sup.g], a 28-gram autopilot-on-a-chip that is but ten centimetres long by 4-cm wide and 1.5 cm in height. The system can control up to 24 servos--flaps, ailerons, split rudders, etc,--and is fully integrated with three-axis gyros and accelerometers, a GPS system, a pressure altimeter and airspeed sensors all affixed to a single, lightweight printed circuit board.

Some of the most-important features of the autopilot are its ability to hold air-speed and altitude, co-ordinate turns and banking, its navigation via GPS and the very soldier-friendly autonomous launch and recovery. All operations of the [MP2028.sup.g] are controlled through the company's proprietary GPS-based [Horizon.sup.mp] ground control software. [Horizon.sup.mp] offers a point-and-click interface for mission planning, parameter adjustment, flight monitoring and mission simulation.

MicroPilot is currently in the throes of developing a full complement of accessories, including its XTender software development kit for user customisation and a compass module that uses dead reckoning in the event of GPS failure.

Other companies develop their own autopilot software. Eads-Dornier was working on its Midas micro UAV with support of the German Federal Office for Defense Technology and Procurement (BWB). Although interest waned and the project was discontinued in early 2003, Eads-Dornier leveraged its experience in that programme to develop the Do-May (Eads-Dornier-Micro Air Vehicle).

The Do-Mav, fresh from completing demonstration flights in both Britain and France in 2003, is on course for additional demo flights this year to German Special Forces units. Eads-Dornier expects contracts to have surfaced by the time these lines are read.

The unit features Eads-Dornier's proprietary flight control software that is unique in that, once the micro drone is launched the software takes control and pilots the unit on a pre-programmed climb rate that gives the thrower time to return to his flight control laptop. The launch sequence begins by the soldier pressing one button on the tiny airframe to start the electric motor. Keeping the first depressed, the soldier presses the second and then tosses the unit into the air. It is the releasing of these two buttons that initiates the automatic launch procedures.

The Do-May carries either a colour TV camera or a black/white image intensifier--it is the light weight of these cameras, which are under 20 grams, that keeps the Do-May in the micro category. The whole unit, with a wingspan of 42 cm, weighs less than 500 grams and the GCS only five kg. Clearly a one-soldier solution.

Mini? Micro?

There is a very grey line defining the mini from the micro systems, but the Atlantic is a boundary with very strong influences. Therefore, the Americans have traditionally seen anything under 16 centimetres as a micro, whereas the Europeans have an altogether different view of micro--as mentioned above, the Do-May, at 42 cm is considered a micro air vehicle.

The Hornet from Aerovironment has a 38 cm wingspan yet is still classified as a micro. This system deserves mention, not because of its size and to which category it belongs, but as it was the first hydrogen fuel cell-powered Micro UAV to fly successfully. March 2003 saw the Hornet fly three separate times, providing test data for its datalink, servos, motor, pumps and other avionic systems.

The Hornet was reportedly stable and simple to control in flight using the manually operated ground control station. The ground controller used an additional radio channel to modulate the rate of hydrogen generated in the vehicle to vary the energy released.

Other research institutes have experimented with micro air vehicles, but few have had success in ruggedising their projects for military use.

Going in Circles

Rotary-winged drones are beginning to gain acceptance and their proliferation seems inevitable. Aerovironment had designed a micro named the Black Widow under a Darpa (Defense Advanced Research Projects Agency)-funded project that ran between 1995 and 1999. The six-inch, two-ounce wonder even won two awards on two continents. The research and development programme resulted in but a single demonstration vehicle being produced--this due to the fact that Darpa's requirements were changed to include hovering, which, of course, implied a design that didn't match the Black Widow--rotary-wing.

This requirement is once again coming to the fore. A "perch and stare" capability that includes vertical take-off/landing and hovering is expected of a drone that must infiltrate, for example, an urban environment, fly to a rooftop and land opposite a window or a scene of action, relay real-time information to the controlling station, then take-off and fly to its landing area or gain another vantage point. Acrobatics hardly possible with a fixed-wing air vehicle.

Many manpack UAV manufacturers consider 300 to 500 ft above ground to be the optimum operating altitude for their minis and micros. But a stop-and-go capability can only enhance a birds-eye view of the action.

To this end Eads-Dornier is developing its Quattrocopter. A Vertical Take-off and Landing (VTOL) solution that runs on four rotors, to enhance stability and manoeuvrability. At present the prototype remains an indoor-flight demonstrator, but the company is forging ahead with what it views as the future of hand-launched UAVs. The Quattroeopter currently offers a one-kilometre operating range with a 20-minute flight duration. Its overall size is 65 cm and it weighs 500 grams.

Another interesting development is the FanTail from Singapore Technologies Dynamics. The Asian Aerospace 2002 exhibition saw a demonstration of the VTOL UAV (at that time called the Mini Tailsitter) and it made a showing at the Paris Air Show in the summer of 2003 under Euro UVS (now UVS International) tent.The air vehicle weighs 2.3 kg and carries a one-half-kg payload. The rotary-wing design makes it suitable for use in confined spaces as only after take-off does the FanTail transition to horizontal flight with speeds of up to 80 km/h.

The FanTail UAV has a vertical, carbon fibre composite fuselage surrounded by a ducted rotor. It went from concept to its first flight in just eight months. And, although still a concept demonstrator, the company explains that it could easily be scaled and customised in the event of customer interest.

Sniffing Out Trouble

One oft-overlooked mission for man-packed drones is that of biological and chemical detection. Here is where the sending of a robot to do a man's job saves lives. And here is another venue where hand-launched drones shine.

BAI Aerosystems was awarded a contract from the US Naval Research Laboratory (NRL) to produce its Dragon Eye hand-launched drone for the US Marine Corps Warfighting Laboratory at Quantico, Virginia. The Dragon Eye is still in production, but with a new name, new capabilities and no longer for the US Marine Corps.

The Evolution, now not constrained by earlier contractual restraints, offers additional payloads to the original Dragon Eye complement. In place of the camera "noses' the drone can carry chemical sensors and biological agent collectors. This capability's development was due to NRL requirements, and made possible by NRL components that were assembled by BAI.

Changing payloads (dual daylight forward and side-looking or black-and-white low light cameras, side-looking infrared or chem/bio) on the Evolution is by detaching one nose and attaching another, as the system is 'built' in the field by joining the centre-wing fuselage section to the left and right wings, adding the tail and then the payload (nose). The design is such that system falls apart upon landing to shed kinetic energy, thereby reducing harm to the components.

The ground control system includes a pair of video goggles, with which the pilot, receiving the video feed from the aircraft, operates the flight controls. Apart from the ground control station is a remote video terminal, wherefrom addition ground troops can view the video feed.

The Evolution is touted as a three-man system, set-up with one GCS operator, one video goggles operator/pilot and one man maintaining security. A dozen or so units have been supplied to non-US Marine Corps military customers, but the type remains on a non-exportable list--a restriction the company believes will change before the end of 2005.

Winging it

The proliferation of mini and micro UAVs is beginning to make permanent marks on defence budgets, as nations recognise yet another way to keep their troops out of harms way, or at least to see what the ground forces will be walking into.

But how much technology is too much? The drone systems are becoming more and more autonomous connecting the waypoint dots is truly soldier-proof--and modular design negates field repairs, so have these systems become a rarely used dead weight or a Godsend?

Each design, from the Inventus S-1 flying wing, through the 'conventional' winged Pointer to the myriad rotary types, offers certain capabilities that are required, by specific missions. The end result being the safety of ground units--infantry soldier, Special Forces or dismounted cavalry--is more a consideration than ever before.

In this vein, how long before the actual organic soldier becomes obsolete?