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Deep space exploration can satisfy humanity's curiosity about the origin of life and the evolution of the universe and enhance our understanding of the internal geological structure and climate change of extraterrestrial bodies. The most direct way to explore extraterrestrial bodies is to sample and analyze the regolith. Drilling is the most effective sampling method, and extraterrestrial regolith drills have helped humans acquire many samples in planetary exploration. Developing high applicable and flexible ERDs for extraterrestrial regolith penetration and sampling has attracted strong attention from scientists and engineers worldwide. This paper presents a detailed review of extraterrestrial drilling technologies. Firstly, the particularities of extraterrestrial drilling are introduced. Then, the ERDs utilized in previous planetary exploration missions and the latest advances are reviewed in detail, including the categories, historical context, and (dis)advantages. Next, the general characteristics of extraterrestrial drilling are summarized, including the mainstream approaches to studying the drilling mechanics and thermophysics. Then, the critical technologies of ERDs, from a conceptual design to a practical prototype, are analyzed in depth. Finally, the prospects for extraterrestrial drilling technology are presented, including water ice drilling, long tunnel boring, deep drilling, and intelligent drilling. [ABSTRACT FROM AUTHOR]

Penetrating planetary regolith is extremely important to explore the secrets inside extraterrestrial celestial bodies. Applying the concept and method of bionics to endow planetary regolith-burrowing robots (PRBRs) with elegant and flexible mobility as natural creatures is gradually becoming a research hotspot in the field of planetary robotics. Compared with traditional penetrating methods, such as drilling and excavation, bioinspired burrowing methods are still seldom studied. This work presents a detailed review of the progress and perspective of bioinspired PRBRs. According to the burrowing mechanisms and strategies of creatures, the current bioinspired PRBRs are divided into seven categories, namely wriggling, undulating, dual-anchoring, grabbing-pushing, reciprocating, granular fluidizing methods inspired by animals, and root growth method inspired by plants. The general characteristics of these robots are summarized in-depth, and the advantages and disadvantages are compared. Then, the key technologies of determining the functionalities and performance of bioinspired PRBRs are comprehensively analyzed, including bioinspired mechanism design, motion control, robot-regolith interaction, and terrestrial validation. Finally, the development trend of bioinspired PRBRs is presented, including new mechanisms and materials, autonomous burrowing control, and intelligent perception and communication. [ABSTRACT FROM AUTHOR]

Regolith penetration for placing instruments into ground and regolith-sampling for re-entry or in-situ analysis play an extremely critical role in searching for alien life and revealing the geological information of extraterrestrial bodies. The planetary regolith sampler (PRS), a type of device that can penetrate, collect, transfer, and stow regolith samples, is commonly equipped on a lander or rover in planetary exploration, and is regarded as essential to broaden the application scenarios of planetary robots. Because of their extensive application prospects in deep space exploration, scientists and engineers worldwide have shown great interest in the design and development of such multifunctional devices. However, owing to the significant environmental differences among extraterrestrial bodies, it is challenging to create a full-featured PRS. To date, a large number of PRSs have been designed and developed for terrestrial scientific research or extraterrestrial regolith exploration. The PRSs utilized in previous extraterrestrial regolith-sampling missions and the latest advancements are reviewed in detail. Next, this work classifies the current PRSs into six categories according their sampling methods, namely drilling, excavating/grabbing, projecting, ultrasonic/sonic, pneumatic, and bio-inspired samplers, and summarizes their general characteristics. The challenges and constraints in sampling extraterrestrial bodies, including terrestrial technology, planetary environment, and remote distance, are analyzed and discussed in depth. The critical technologies for PRSs to change from a conceptual stage to a practical prototype are detailed, including design and fabrication, tool–regolith interaction, terrestrial validation, autonomous control, and sample fidelity. Finally, the critical trends of PRS are presented, covering near-term robotic exploration to cover the full geography to long-term human settlements. • A comprehensive review on extraterrestrial regolith-sampling technology. • A historic context of humans beings' activity to explore extraterrestrial regolith. • The challenges and critical technologies in extraterrestrial regolith sampler. • The newest technology advancement and future tendency to sample planetary regolith. [ABSTRACT FROM AUTHOR]