lighter-than-air vehicles - Defense Innovation Marketplace

Today, LTA vehicles are used by all branches of the armed services and a number of othergovernment agencies requiring persistent ISR capabilities. Moreover, efforts are under way todevelop airships capable of airlift and logistics capabilities.Vehicle ClassificationLTA vehicles fall under two primary classes: unpowered and powered (Figure 1). Unpoweredvehicles include both balloons and tethered aerostats. Powered LTA vehicles are called airshipsand can be further categorized as either conventional or hybrid design. Conventional airships,commonly known as blimps, rely purely on buoyancy for lift, whereas hybrid airships use theirstructure or variable thrust direction to create lift by additional means. 2Figure 1: Air Vehicle Categorization 2AerostatsTethered aerostats are unmanned, non-rigid, LTA vehicles that remain anchored to the ground byone or more cables (Figure 2). The main tether not only holds the aerostat in position but alsotypically provides power to the aerostat’s payload and a data link to provide communicationsbetween the payload and the ground control station. The main envelope of an aerostat is filledwith helium, while the stabilizing tail fins are normally filled with air. The payload is located in aventral dome under the envelope. The aerodynamic shape of the envelope and the tail finsprovide a stable platform in the presence of modest winds and gusts. When moored to the6