Investigation on the landing-impact tests of the lunar lander and the key technologies

The lunar exploration of China is underway, and a lunar lander will be launched in the next step. In order to verify the stability and reliability of the lunar lander at impact, landing-impact tests on earth are urgently needed. Lunar terrain and lunar soil, which make strong influence on the landing performance of the lunar lander, were depicted in detail. Another important characteristic of the lunar surface environment is the lunar gravity, which is only one-sixth of the earth's gravity, so the lunar gravity has to be simulated to obtain dynamic similarities. Three techniques, including their principles and apparatuses, were mentioned to simulate lunar gravity. The tests were divided into two categories: the full-scale test with the simulated lunar gravitational field acting and the 1/6-scale test with the earth's gravitational field acting. The scaling relationships between the prototype of the lunar lander and two models used for the landing-impact tests were presented, and the apparatuses and procedure of both the tests were illustrated in detail. At last, a technique was presented to simulate the landing modes. Surveys indicate that the results of the two tests bear a remarkable similarity. Due to that the lunar terrain and lunar soil does not be simulated sufficiently in the tests, there is a gap between the tests data and the actual data.