Flying - With strings attached

The discovery of the stabilizing effect of a midtether mass or drag has been a significant step forward in the search for practical realization of the promise of a useful towed-tether payload-delivery system. A small-scale experiment was designed to enable rapid observation of the changes in tether behavior as variations were made in the configuration. The experimental setup consisted of a 1-m-diam ceiling fan at a height of 3 m from the floor. A 3-m-long tether was attached to the tip of one blade of the fan. Initially, a small range of masses were attached to the free end of the tether and the behavior of the masses was studied. An accident occurred when the tether tangled, creating a loop at a point about 30% of the total length above the end body. A new set of experimental studies was made with a range of masses attached at a range of positions along the tether at a range of fan speeds. The results show that the free end mass was stable over the range of fan speeds. The diameter of the end-body circle was reduced by half, to around 5% of the diameter of the towing circle.