K. Tateyama, College of Science and Engineering, Predicting the Impact Force on the Landing Gear of a Lander at a Lunar Landing

The Japan Aerospace Exploration Agency (JAXA) is planning a survey mission to the moon which will start in 2011 as part of the Japanese Lunar Inquiry Mission, namely, the SELENE Project. The mission will involve JAXA sending unmanned probes to the lunar surface in order to collect precise information on the terrain and the environment of the moon. The modules, called “landers”, will fall downward, reverse their engines at a height of 3 m from the lunar surface, turn their engines off, and then land with a free fall. The surface of the moon is covered with fine, dry soil, similar to dust, and the gravity acceleration is about 17% of that on the Earth. Despite these conditions of the lunar surface which will cushion the impact on the landing gear during the landing, the impact force must be predicted ahead of time in order to design the landing gear of the landers with accuracy. The authors have conducted some model experiments and a numerical simulation to study the force of impact that will act on the landing gear, and they have predicted this force through the numerical simulation by supposing an actual lander.