Landing Dynamic and Key Parameter Estimations of a Landing Mechanism to Asteroid with Soft Surface

Abstract

It is of great significance to utilize a landing mechanism to explore an asteroid. A landing mechanism named ALISE (Asteroid Landing and In Situ Exploring) for asteroid with soft surface is presented. The landing dynamic in the first turning stage, which represents the landing performance of the landing mechanism, is built by a Lagrange equation. Three key parameters can be found influencing the landing performance: the retro-rocket thrust T, damping element damping c1, and cardan element damping c2. In this paper, the retro-rocket thrust T is solved with considering that the landing mechanism has no overturning in extreme landing conditions. The damping element damping c1 is solved by a simplified dynamic model. After solving the parameters T and c1, the cardan element damping c2 is calculated using the landing dynamic model, which is built by Lagrange equation. The validities of these three key parameters are tested by simulation. The results show a stable landing, when landing with the three estimated parameters T, c1, and c2. Therefore, the landing dynamic model and methods to estimate key parameters are reasonable, and are useful for guiding the design of the landing mechanism.