Low-Thrust Maneuverability Using Bilinear Tangent Guidance near Small Bodies

This paper examines the ability of a bilinear tangent guidance law to perform continuous-thrust, single-burn orbital maneuvers in the small-body orbital environment (solar radiation pressure, etc.) and the capability of a Newton-Raphson predictor-corrector algorithm to perform free-time, state-to-state spacecraft guidance on initial state perturbations. This paper shows that low-thrust bilinear tangent is able to perform a wide variety of maneuvers with a wide variety of thrust levels around asteroid Bennu. Additionally, this paper shows that even with a high control authority, the size of initial state perturbations that can be corrected depends on the size of the target state's complex backward-reachable subspace and the location of the initial state of the maneuver in that subspace. For example, a 5 mN thruster on a 1000 kg spacecraft performed an aggressive shape and plane change maneuver for less than 3.5 g of fuel. The derived guidance algorithm then corrected 100% of initial state perturbations drawn from delta r similar to N(33,17.5) m and delta v similar to N(3,1.7) mm/s distributions. Ultimately, this paper shows that Newton-Raphson predictor-corrector bilinear tangent guidance is a capable guidance scheme when used on perturbations that lie within the reachable subspace of the target state.