Design and experimental performance verification of a thermal property test-bed for lunar drilling exploration

• Published in: Chinese journal of aeronautics 2016-10, Vol.29 (5), p.1455-1468
• Main Authors: Zhang, Tao, Zhao, Zeng, Liu, Shuting, Li, Jinglin, Ding, Xilun, Yin, Shen, Wang, Guoxin, Lai, Xiaoming
• Format: Article
• Language: English
• Subjects: Drilling test bed; Lunar drill; Lunar environment simulator; Temperature measurement; Thermal property
• ISSN: 1000-9361
• DOI: 10.1016/j.cja.2016.03.008

Chinese Chang＇e lunar exploration project aims to collect and return subsurface lunar soil samples at a minimum penetration depth of 2 m in 2017. However, in contrast to those on the Earth, automated drilling and sampling missions on the Moon raise the risk of burning bits. Test-beds are required for testing the thermal properties of drill tools in a lunar environment. In this paper, a novel temperature measuring method based on thermocouples and a slip ring was proposed. Furthermore, a data acquisition system for a drilling process was designed. A vacuous, cryogenic, and anhydrous soil environment simulating the lunar surface was established. A drilling test-bed that can reach a depth of 2.2 m was developed. A control strategy based on online monitoring signals was proposed to improve the drilling performance. Vacuum and non-vacuum experiments were performed to test the temperature rising effect on drill tools. When compared with the non-vacuum experiment, the vacuum temperature rise resulted in a 12 ℃ increase. These experimental results provide significant support for Chinese lunar exploration missions.