40
2 Environment Analysis of Lunar Soft Landing Exploration
Fig. 2.13 The relationship between the static bearing capacity and the depth of lunar soil in different
regions
The comparison between the ultimate bearing capacity of lunar soil and the vertical
stress design of the various probes (such as the foot pad of “Apollo” lunar lander, the
foot pad of “Surveyor” lunar lander and the wheel of “Apollo” lunar rover) and the
one-foot-stand astronauts is shown in Fig. 2.14. As shown in the figure, the vertical
stress value applied in engineering design is much smaller than the ultimate bearing
capacity on the same contact width. The margin is enough.
2.5.3 Electromagnetic Properties
Conductivity and dielectric property are the important parameters that characterize
the scattering and transmission of electromagnetic energy inside the lunar soil and
rock layer. It is the response characteristics of lunar substance to electric current.
1. Conductivity of Lunar Substance
Lunar substance is mainly composed of silicate and is typically low-conductivity
material. Due to loss of water, the conductivity of lunar substance with frequency
lower than 1 Hz is equal to DC conductivity. Its value is extremely low and primarily
up to temperature.
2 Environment Analysis of Lunar Soft Landing Exploration
Fig. 2.13 The relationship between the static bearing capacity and the depth of lunar soil in different
regions
The comparison between the ultimate bearing capacity of lunar soil and the vertical
stress design of the various probes (such as the foot pad of “Apollo” lunar lander, the
foot pad of “Surveyor” lunar lander and the wheel of “Apollo” lunar rover) and the
one-foot-stand astronauts is shown in Fig. 2.14. As shown in the figure, the vertical
stress value applied in engineering design is much smaller than the ultimate bearing
capacity on the same contact width. The margin is enough.
2.5.3 Electromagnetic Properties
Conductivity and dielectric property are the important parameters that characterize
the scattering and transmission of electromagnetic energy inside the lunar soil and
rock layer. It is the response characteristics of lunar substance to electric current.
1. Conductivity of Lunar Substance
Lunar substance is mainly composed of silicate and is typically low-conductivity
material. Due to loss of water, the conductivity of lunar substance with frequency
lower than 1 Hz is equal to DC conductivity. Its value is extremely low and primarily
up to temperature.