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Jump ahead to 2016, and the BeaverWorks group is developing what is, in effect, a Locust on steroids: a high-speed, in-flight-deployable micro-UAV called Firefly. Firefly is longer (around 16-inches long), but about the same width as Locust. And, like Locust, Firefly will also deploy from a mothership aircraft, unfold its wings, and fly autonomously. The main performance difference between the two vehicles is speed. Whereas Locust was developed to maximize endurance using electrical propulsion and flies at approximately 60 mph, Firefly’s mission requires cruise speeds of around Mach 0.8, or To test propellant chemistry and motor geometry, this test motor is used. The about 550 mph at an altitude of around 20,000 motor flame is the narrow orange; the white-blue wider flame to the right is from a torch used to burn off toxic exhaust chemicals. (Beaver Works photograph) feet. To generate sufficient thrust for such high flight speeds, a solid rocket propulsion system is used. Whereas other applications of small solid rockets boost a rocket to altitude quickly (and therefore expend its fuel in a few seconds), Firefly is designed to fly for several minutes. Firefly will offer its users the novel capability of deploying small, self-flying electronic payloads in mid-air, capable of filling a wide variety of missions. The speed, range, and autonomy of Firefly have never before been achieved in a vehicle this small. To maximize the endurance of the vehicle, the team is developing a custom solid rocket propulsion system using a cocktail of various fuels, burn rate modifiers, and catalysts to tune the rocket motor for efficiency, ignition stability, and burn rate. To protect the vehicle chassis and onboard electronics from the heat generated by the rocket motor, ceramic-fiber-silicone composite liners are being developed and a ram-air intake cooling barrier is being designed.

SPECIAL SECTION

Student Projects: tiny rocket drones, hyper-speed transport, a composite rocket, and a lunar orbit competitor

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MIT AeroAstro annual magazine 2015-2016Aeroastro 2015 16  

Annual magazine review of MIT Aeronautics and Astronautics Department research and educational initiatives.

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