Therefore, it important to study landing performance in different conditions in order to analyze the landing stability boundary, and to propose reasonable landing suggestions to support China's small celestial body exploration.

In a research article recently published in Space: Science & Technology, researchers from Beijing Institute of Spacecraft System Engineering, Harbin Institute of Technology, and Polytechnic University of Milan have established a simulation model of a landing mechanism under different landing conditions, analyzed the sensitivity of the key parameters affecting the landing performance, and verified correctness of the simulation via experimental tests, which can provide guidance for a landing mechanism to land stably on a small celestial body.

First, the authors briefly reproduce the landing mechanism and the landing simulation. The small celestial body landing mechanism used in the simulation contains a landing foot, landing legs, cardan element, damping element, equipment base, and more. In simulation, two scenarios are taken into consideration: the landing mechanism landing toward the landing slope with V_x > 0; and the landing mechanism landing away from the landing slope with V_x < 0.

In each scenario, three landing modes are classified according to the contact order between the landing foot and the landing slope, i.e. (a) 1-2 landing mode, (b) 2-1 landing mode, and (c) 1-1-1 landing mode (with 30° yaw angle). For all landing modes in both simulation scenarios, the landing mechanism turnover is prevented by the retro-rocket, and there is no sliding of the landing feet.