Modeling the Movement of Vehicles on the Binary Asteroid Systems

This paper investigates the surface dynamics of particles on the primary of the Sphere-Restricted Full 2-Body Problem (SRF2BP), which is the celestial body system consisting of an arbitrarily shaped celestial body and a spherical celestial body. The primary is considered as an irregular-shaped body while the secondary is considered as a sphere. The motion equation of the SRF2BP has been presented. The locations of surface equilibrium for particles, the linearized equations of particles relative to the surface equilibrium, and the characteristic equation of the surface equilibrium have been investigated. The surface mechanical environment of a special binary asteroid 243 Ida and Dactyl has been studied with considering the polyhedron model of Ida including 2522 vertices and 5040 faces as well as the point mass model of Dactyl. We present the influential mechanism of the natural trajectories and surface features of Ida. Some trajectories are unstable, which means that a small disturbance can cause a large variety of trajectories. This can help us to find better trajectories for landers and vehicles of space missions. The effect of Dactyl to the motion of particles on Ida is quite small. However, for some particles, the effect of Dactyl can not be neglected. Monte Carlo simulations are used to find the characteristic of particles’ trajectories on different initial positions with static initial state. Furthermore, Monte Carlo simulations are performed to see the characteristic of particles’ trajectories with different initial positions and initial velocities. We mapped the slope angle and the gravitational acceleration with considering the Coriolis effect onto the surface of Ida. For landers, the plain/basin/crater/valley regions are good landing target; and the gaps, hilltops, convex surface, humps, as well as saddles are bad landing target. For vehicles, the concave surface, impact craters, as well as valleys with small slope angle can be used for landing target and initial position. If vehicles enter the regions of gaps, impact craters, as well as valleys with large slope angle, it may be hard to move out; thus these regions are not suitable for vehicles. This paper can provide reference and suggestion to the engineering design of the space mission to binary systems.