Neighboring Optimal Guidance for Aeroassisted Orbital Transfer

A neighboring optimal guidance scheme for a nonlinear dynamic system is devised with stochastic inputs and perfect measurements as applicable to fuel optimal control of an aeroassisted orbital transfer vehicle. For the deterministic nonlinear dynamic system describing the atmospheric maneuver, a nominal trajectory is determined. Then, a neighboring, optimal guidance scheme is obtained. Taking modeling uncertainties into account, a linear, stochastic, neighboring optimal guidance scheme is devised. Finally, assuming the additive character of the stochastic effects, the optimal trajectory is approximated as the sum of the deterministic nominal trajectory and the stochastic neighboring optimal solution. Numerical results are presented for a typical aeroassisted orbital transfer vehicle.