Free-wing unmanned aerial vehicle as a microgravity facility

A conceptual study is presented on the dynamics of a proposed unmanned aerial vehicle (UAV), which is designed as a testbed for studying the influence of micro- (or partial) gravity on various biological or physical phenomena. The design option of a torque-controlled wing, free to rotate about a spanwise axis, is evaluated in terms of gust sensitivity and automatic settling at a certain g-setpoint. The complete set of nonlinear equations of motion of such a free-wing UAV are derived using Lagrange's equations. A linear aerodynamic model of the UAV is used to investigate its flight dynamics, gust sensitivity, and ability to fly micro- and partial gravity flights. Comparison to a similar fixed-wing UAV shows considerably decreased gust sensitivity.