Beam-Riding Analysis of a Parabolic Laser-thermal Thruster

Abstract

Flight experiments with laser-propelled vehicles (lightcrafts) are often performed by wire-guidance or with spin-stabilization. Nevertheless, the specific geometry of the lightcraft’s optics and nozzle may provide for inherent beam-riding properties. These features are experimentally investigated in a hovering experiment at a small free fliight test range with an electron-beam sustained pulsed CO2 high energy laser. Laser bursts are adapted with a real-time control to lightcraft mass and impulse coupling for ascent and hovering in a quasi equilibrium of forces. The flight dynamics is analyzed with respect to the impulse coupling field vs. attitude, given by the lightcraft’s offset and its inclination angle against the beam propagation axis, which are derived from the 3Dreconstruction of the flight trajectory from highspeed recordings. The limitations of the experimental parameters’ reproducibility and its impact on flight stability are explored in terms of Julia sets. Solution statements for dynamic stabilization loops are presented and discussed.