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53 with 4 Gbytes of onboard memory for data logging in a compact and robust package rated to IP68 for deployment in harsh environments. Slovenian company C-Astral provided a preview of the Advanced Technology Light Acquisition System (ATLAS), a new hand-launched fixed- wing UAV that it plans to unveil at the InterGeo geospatial event in October, along with a higher end system, the Bramor gPX.  Available from the fourth quarter of 2016, ATLAS is intended as a competitor for lower-end ‘entry level’ systems from the likes of SenseFly and Delair, providing longer endurance and a compact ground control station that can be installed in a car and used with any computer. The mission planning software enables multiple missions on the same flight, and combines its functionality with situational awareness-enabled mission flight control software, along with common C-Astral features such as full mission re-planning and system control in-flight, and multiple flight geometries and terrain-following for stable ground sampling distance maintenance.  With a 155 cm wingspan, ATLAS is 82 cm long, weighs 2 kg on take- off and packs down small enough to be checked in as airline luggage, C-Astral’s Marko Peljhan told us. Powered by a lithium battery, an electric motor and a two-bladed tractor propeller, it offers up to 70 minutes of flight time and a range of 60 km. It is autonomous from hand launch to parachute landing, is designed to be rainproof and to resist 30 knot winds and operate in temperatures from -25 to +45 C. Like C-Astral’s other vehicles, the structure is made from composite materials reinforced with carbon, Kevlar or Vectran fibres, with Kevlar underneath for toughness and RF transparency for the integrated antenna system, and CFRP for lightness in the wings, which have magnetically attached winglets and an easily replaceable pitot tube. Payload and battery modules are under the top cover and lift out on handles. Wiring is integrated into the structure to minimise the risk of breakages and shorts. Typical payload modules are EO and multi-spectral sensors. Hirth now offers a range of six off-the-shelf gasoline and heavy fuel- burning two-stroke engines for UAV applications, covering the 8-100 bhp range, Dietrich Kehe reported; UST profiled the company’s 183 cc air-cooled twin in issue one. The current smallest, lowest-power engine is an 8 hp air- cooled 100 cc twin; its largest, highest powered unit a 100 hp water-cooled 939 cc inline three. The respective weights are 3.4 and 47.5 kg. Lee Estingoy reported that a new development from Hacker Motor is a range of servos that have two-way communications yet are “standard price” rather than high end in terms of cost. They feature a digital encoder, he noted. Established supplier of generators for UAV applications, Sullivan, is now involved in developing hybrid powertrains for multi-rotor use. James Hudson explained that the concept is to use an internal combustion engine solely to drive a generator that in turn supplies the electric motors powering the four or more rotors. In this series hybrid arrangement, the IC engine and electric motors are linked by an appropriately sized Sullivan generator and associated power management unit, which means that no battery is required. Quadcopter and similar UAVs are notoriously energy-hungry. The upshot of the hybrid solution, said Hudson, is that the craft can fly further for a given take- off weight. That is not only because the fuel for the IC engine is far more energy- dense than a state-of-the-art battery but also because as the mission proceeds its weight diminishes, whereas that of a battery is consistent. An alternative is to use a small battery to fill the gap between a system sized for average power and the peak power requirement for take-off. Hudson told Unmanned Systems Technology | June/July 2016 The power management unit for Sullivan’s hybrid powertrains