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05 Sep 11. Small unmanned aircraft systems (UAS) provide valuable intelligence, surveillance and reconnaissance (ISR) capabilities for units at the infantry company level and below, allowing over-the-next-hill imagery or short-term monitoring of convoys as an example. State-of-the-art battery power for these small UASs, however, has limited the duration of missions to about two hours. DARPA’s Tactical Advanced Power (TAP) program has addressed the power limitation by developing a compact solid oxide fuel cell (SOFC) fueled by propane, a very high energy density hydrocarbon fuel. DARPA researchers have also developed the
Stalker XE, a small UAS powered by this fuel cell to provide extended mission endurance for more than eight hours with the reliability and ruggedness required to perform real-world missions. The Stalker XE has demonstrated an improvement of more than four times the endurance of existing state-of-the-art small unmanned aircraft systems. The fuel cell was the basis for the hybrid power source on the Stalker XE, in which the high energy density fuel cell system was combined with a conventional lithium polymer battery to handle peak power requirements. Its high energy density hydrocarbon fuel to handle energy storage rather than a relatively low energy density battery. The Stalker XE enables persistent surveillance operations for small units. As a 22-pound bungee-launched system, it operates without the large footprint and high cost of current tactical UAS platforms. The enabling technology is the compact SOFC developed by DARPA for portable power applications, but the notable achievement of the Stalker XE demonstration is ruggedization of the advanced SOFC power source and integration into a fieldable platform. Stalker XE was subjected to rigorous flight-testing, where it was required to perform back-to-back flights on a single airframe and single fuel cell with turnaround times of less than 30 minutes. During these tests, the aircraft encountered wind gusts of 46 mph and sustained winds as high as 28 mph. The system also performed at altitudes of greater than 15,000 feet. The TAP portfolio program develops advanced portable power and energy in program efforts ranging from fundamental materials and chemistry to systems engineering of mature portable power systems. The fuel cell power source in the Stalker XE was developed and matured under DARPA’s Palm Power and Robust Portable Power Sources programs. Under the TAP program, the fuel cell system was ruggedized for integration into a fieldable small UAS. (Source: ASD Network)

05 Sep 11. Unmanned reconnaissance and target engagement combined:
WABEP demonstrator flights successfully completed. Rheinmetall Defence of Düsseldorf and its partner Israel Aerospace Industries (IAI) have successfully tested the new WABEP system of systems. The trials focused on the reconnaissance and strike function of the WABEP, which is slated to become the Bundeswehr’s next unmanned air vehicle system. Currently undergoing development at Rheinmetall, WABEP (which stands for
“Wirksystem zur abstandsfähigen Bekämpfung von Einzel- und Punktzielen” or “Weapons system for standoff engagement of individual and point targets”) consists of a Rheinmetall-made KZO unmanned reconnaissance air vehicle and a “Harop” attack drone from IAI. The KZO, whose German initials are short for “small air vehicle for target location”, is packed with high-performance sensors, enabling it to detect and identify targets; the Harop attack drone is responsible for precision engagement of the assigned target, destroying itself in the process. The successfully executed tests mark the completion of the contractor trials. The next step in the realization of the project is a demonstration phase with Bundeswehr participation, which is being conducted at present. During contractor test flights, the Harop attack drone and the reconnaissance and wireless data transmission components in the Rheinmetall KZO system opera

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