Invariant manifold guided self-triggered MPC tethered asteroid landing

The weak and highly irregular gravitational fields of asteroids make it difficult to construct natural, stable, and predictable reference orbits for landing and proximity operations. Current asteroid landing and deployment methods often rely on high-frequency closed-loop correction, which can lead to high propellant consumption and strong dependence on continuous online control. In this paper, we focus on a tether-assisted asteroid probe architecture, in which the tether is introduced as part of a specific mission concept to provide deployment safety, passive recovery capability, and internal momentum redistribution under weak-gravity conditions. Under such a configuration, frequent active correction may further aggravate the coupled dynamics of the tethered system. To address this issue, the global trajectory-planning problem is reformulated as a structured reference-tracking problem by exploiting equilibrium-point manifold dynamics. During the separation of the tethered asteroid probes (TAP), the system’s gravitational potential energy is converted into controllable relative kinetic energy through momentum exchange. This enables autonomous and economical evolution along a prescribed manifold without continuous active orbit correction. A self-triggered MPC scheme is then employed, in which the triggering interval is adjusted online and a relaxation mechanism is introduced. This significantly reduces the frequency of online optimization and the control burden while maintaining constraint satisfaction and tracking accuracy.