A Review of Different Aspects of Off-Earth Drilling

Abstract

Off-Earth drilling may be assumed as the second phase of space exploration to discover the unrevealed subsurface on the planetary bodies. It accelerates future space objectives such as in-situ propellant production, mineral exploitation, and space tourism. Owing to the rampant progress in modern technology, the new drill tools mounted on the sophisticated robots are capable to drill the planetary regolith dispersed on the celestial objects; however, formidable obstacles such as microgravity, vacuum condition, and temperature fluctuation as well as the weight limitation, lack of real-time drilling analysis, and remote robot-operator communication impose pressing restrictions on the quick development of space drilling tools. In this study, research on the past and present aspects of off-Earth drilling has been implemented to illuminate the horizon of this technology in the near-term future. The context encompasses a detailed description of the limitations, applications and mechanisms of the different drilling techniques adopted for planetary bodies. A particular emphasis is put on the hydraulic power systems which have not been satisfactorily deployed in off-Earth drilling yet. The research strives to glance over the pivotal aspects of off-Earth drilling to contribute to the future drilling programs planned by the national and private space agencies.

Land Subsidence Assessment for Wind Turbine Location in the South-Western Part of Madagascar

“…The grain-to-grain transition generates stress transfer from the fluid to the solid phase as result of fluid withdrawal. Effective stress increases within formation and, therefore, compaction [5,50]. Cumulative compaction of the subsurface layers results in subsidence and exposes on the surface.…”

“…The elevation of the ground gradually decreases as the underground fluid is pumped out. On the one hand, human activities, such as depletion of groundwater, underground mining, and oil and gas extraction, can cause this subsidence [1][2][3][4][5][6]. On the other hand, natural causes such as compaction, sinkholes, and thawing permafrost can also induce subsidence of the land [7,8].…”

A Review of the Geomechanics Aspects in Space Exploration

“…Extraterrestrial drilling operations encounter two serious types of challenges, environmental and technical ones [107]. Environmental challenges stem from the difference between the physics of planetary bodies and that of Earth.…”

“…The fourth environmental issue is the abrasiveness of lunar and Martian regolith; the abrasive, sharp particles of the lunar and Martian regolith can penetrate into the working parts of the drilling machine and gradually impair them. Moreover, drilling through such abrasive material accelerates the bit's wear [107].…”

Robotic drilling for the Chinese Chang’E 5 lunar sample-return mission

“…For samples exposed to the surface, excavation is a popular method because of the unique advantage of obtaining a large sample volume in a single operation (Zhang et al, 2019b; Skonieczny et al, 2016). For deeply buried samples, drilling is currently the most feasible approach for removing the covered regolith layer and reaching the geological interior with the least disturbance to the surrounding regolith (Knez and Khalilidermani 2021; Skonieczny et al, 2016). In addition, drilled samples can provide more scientific information than randomly bulked samples because sample information related to vertical stratification can be preserved (Zacny et al, 2008).…”