Editorial: Intelligent Manufacturing and Design Under Challenging Conditions

1. Introduction

As readily accessible resources near the Earth’s surface are gradually depleted, the focus of resource development and scientific exploration is increasingly shifting toward extreme environments, including deep earth, deep sea, and deep space [1,2,3]. In the deep-earth domain, the former Soviet Union’s Kola Superdeep Borehole reached a drilling depth of 12,262 m, pioneering ultra-deep drilling at the 10,000 m scale [4]. In recent years, China has also successfully initiated the drilling of multiple 10,000 m-class wells, such as Chuanke-1 and Take-1, with notable indications of oil and gas reported [5,6]. In the deep-sea domain, China achieved in 2023 the first acquisition at the global scale of deep-sea sediment and gas-hydrate samples under a simultaneously preserved pressure of 14.5 MPa and a temperature of 3 °C at a water depth of 1385 m in the South China Sea [7]. In the deep-space domain, the U.S. Artemis program is advancing lunar resource development, while China’s Chang’e-6 mission employed fidelity coring to enable in situ sampling and return of lunar materials [8]. Engineering endeavors once regarded as science fiction, such as deep-sea mining, ultra-deep drilling at the 10,000 m scale, and lunar mining, are gradually evolving from demonstration projects into routine applications [9]. However, these extreme physical environments pose formidable challenges in terms of cost, efficiency, and operational safety [10]. Consequently, the intelligent design and manufacturing of equipment for extreme environments has become a pivotal strategy to address these challenges by enabling autonomous decision-making operations, in situ sensing, and closed-loop control, as well as remote collaboration and health management.

The core of intelligent equipment design for extreme environments lies in augmenting the capability to establish and stably maintain controlled “internal working conditions”, thereby ensuring equipment reliability and sample fidelity. On the one hand, for deep-earth and deep-sea drilling and sampling, integrated systems combining intelligent temperature regulation and pressure preservation have been developed. For example, coupling an intelligent thermal control system with hollow glass microsphere composite insulation can effectively maintain the in situ temperature of deep cores [11]. In addition, a self-triggered sealing system based on a ball valve and a flip-cover valve has demonstrated stable operation under extreme conditions of 150 °C and 140 MPa, providing support for resource extraction in deep seas and ultra-deep wells [7]. On the other hand, deep-space environments, such as the lunar surface, feature extreme temperature swings from −180 °C to 130 °C together with high-vacuum conditions, making the thermal management of electronic devices a key enabling technology [12,13]. Recent advances mainly include high-efficiency passive heat dissipation techniques, such as phase-change cooling materials and loop heat pipes, as well as radiation heat-transfer optimization designs tailored for vacuum environments, to ensure stable instrument operation under the extreme thermal conditions on the lunar surface [14,15,16]. Finally, at the level of integrated intelligent design and manufacturing, international efforts have established technical frameworks involving digital twins, multi-physics coupled design, and intelligent control to achieve reliable, efficient, and autonomous operations [17,18,19,20].

Based on this foundation, this Special Issue continues to focus on intelligent manufacturing and equipment design for extreme environments, including deep earth, deep sea, and deep space, with the aim of advancing related systems from experience-driven development toward a high-reliability paradigm that is synergistically driven by models and data. The core research topics include the following: the design of intelligent drilling and coring equipment and robotic systems for extreme environments; research on deep in situ environment reconstruction and high-temperature/high-pressure simulation testing methods and platforms; and the reliability enhancement of critical components and multi-physics-based structural optimization under extreme conditions.

2. Overview of the Contributions

To address these challenges, this Special Issue has presented a series of studies spanning the aforementioned scope. The latest contributions can be categorized into the following three areas:

2.1. Design of Intelligent Drilling and Coring Equipment and Robotic Systems for Extreme Environments

The published studies address two representative task scenarios, namely, temporary support advancement in deep coal-mine short-wall roadways and lunar sampling; they have established a system-level design concept spanning “support–rock breaking–sampling–core-tube replacement and storage”. For 15–40 m deep coal-mine short-wall faces in integrated drilling–mining operations, where conventional temporary support methods struggle to balance stability and efficiency, Ma et al. proposed a self-propelled temporary support robot that achieves “walking under load” through mutual pushing and pulling between two support units. They developed both a stable-support mechanical model and a load-walking dynamic model. By formulating boundary criteria and equipment–rock interaction mechanisms, they clarified the range of support forces that enables stable load-assisted advancement. Finite element analysis and multibody dynamics simulations were further combined to evaluate structural and floor stresses as well as the critical advancement conditions. In particular, incorporating Stribeck friction markedly improved the predictive accuracy for the required push–pull forces, thereby providing a more reliable analytical framework for the refined modeling and control of heavy-duty equipment under complex contact conditions.

In addition, for crewed lunar sampling missions, Zhang et al. noted that a single sampling mode poses higher risks under harsh lunar conditions and operational constraints. They proposed a dual-mode hybrid coring concept that combines high-frequency percussive penetration with rotary drilling. Key adjustable parameters were reported, including an impact frequency of 0–20 Hz, an impact energy of 5–15 J, and a rotational speed of 0–300 rpm, to accommodate varying depths and media while improving coring efficiency and preserving stratigraphic information. Their design also considered the coordination between handheld operations and lander- or rover-mounted operations, aiming to reduce astronaut workload and enhance sampling safety and stability.

Furthermore, targeting deeper lunar rock sampling, Wen et al. proposed a functional division between a surface core-tube replacement and storage executor and an underground wire-line self-excavating coring robot, referred to as WSC. The surface unit performs core-tube replacement and storage of filled tubes, whereas the underground unit is responsible for in-hole anchoring, thrusting, and combined rotary–percussive rock breaking and coring. A model describing the depth-dependent evolution of anchoring support force was established to guide the power and thrust strategy at different depths. The authors emphasized that anchoring fluctuates markedly in the shallow 0–4 m interval and thus requires real-time adjustment, whereas it becomes more stable at greater depths, enabling higher-power operation. Structural features such as anchoring lock mechanisms, temporary cuttings storage, and automatic cuttings removal were also incorporated to support continuous operation in the absence of drilling fluids.

2.2. Research on Deep In Situ Environment Reconstruction and High-Temperature and High-Pressure Simulation Testing Methods and Platforms

Research in this area has progressed in two collaborative directions: “high-precision reconstruction and maintenance of in situ temperature and pressure environments” and “high-temperature and ultra-high-pressure ground simulation testing equipment for pressure-preserved coring tools.” First, Peng et al. proposed the Deep In Situ Environment Reconstruction and Core Transfer System (SERCT), which uses water as a medium for a working condition corresponding to a depth of approximately 2500 m, with 95 °C and ≤70 MPa. To address the control difficulties caused by the coupling of temperature and pressure, they proposed a P–T decoupling control approach based on water’s density-equivalent P–T curve interpolation. After decoupling, fuzzy PID dual-mode pressure control and fuzzy PID temperature control based on gray prediction were applied. Additionally, segmented electric heating was used to improve temperature field uniformity. The system emphasizes that temperature and pressure fluctuations due to valve and pushrod movements during core preparation and testing must be controlled within ±3% of the range, thereby providing methodological and system-level support for “fidelity” physical property testing and cross-chamber transfer.

Second, Huang et al. addressed the development and testing requirements for deep pressure-preserved coring tools by constructing an in situ simulation device consisting of a high-temperature and ultra-high-pressure testing chamber and a coring drive module. They provided key specifications, including a maximum working pressure of 140 MPa and a temperature of 150 °C. They further validated through experiments that the segmented testing chamber could stably withstand up to 190 MPa and remain in the elastic deformation stage at 150 °C without leakage. The drive module can provide a stable rotational speed of up to 150 rpm under a 140 MPa sealing pressure. This provides reproducible equipment and validation for conducting pressure-preserved coring simulation tests on the ground and reducing high-risk and high-cost field trials.

Overall, these two studies complement key elements of the deep in situ fidelity testing chain from the perspectives of “temperature–pressure decoupling and stable maintenance control algorithms and process platforms” and “high-temperature and ultra-high-pressure load-bearing and dynamic sealing test equipment platforms,” thus laying the foundation for an integrated testing system for coring, transfer, preparation, and testing under extreme environmental conditions.

2.3. Enhancement of Critical Component Reliability and Multi-Physics Structural Optimization Under Extreme Environments

Focusing on this research direction, related findings provide practical frameworks and engineering evidence from three perspectives: thermal–electrical coupling reliability assessment, structural optimization under complex fluid–solid multiphase erosion, and innovative designs for downhole power and signal transmission structures. First, in terms of electronic packaging reliability, Min et al. conducted high-voltage stress tests on semiconductor packaging under data center immersion cooling conditions, revealing the nonlinear growth of heat accumulation and leakage current due to increasing stress voltage. Overvoltage in air environments leads to significant heat buildup and an increase in leakage current, which accelerates device degradation, while immersion cooling enhances heat dissipation, thereby suppressing leakage current growth. These findings provide a basis for design margins and accelerated testing thresholds for packaging under extreme heat dissipation conditions.

Next, in the optimization of key hydraulic components for deep downhole coring systems, Guo et al. focused on the issues of differential motion component sealing failure, jamming, and erosion in in situ pressure-preserved coring (IPP-Coring) systems. They performed a mechanistic analysis of flow field velocity, pressure drop, and vortex structure using computational fluid dynamics (CFD) and proposed synergistic improvements to geometric parameters and outlet structures. By increasing the seat diameter from 30 mm to 40 mm, the maximum flow rate and pressure drop were reduced to 0.55 and 0.2 times of the original, respectively. Furthermore, changing the seat outlet from a right angle to an arc could further shorten the vortex area and reduce near-wall velocity and pressure drop. Particle trajectory and erosion calculations showed that the improved structure reduced the average erosion rate to only 0.42 times that of the original structure. More importantly, field tests verified that the surface erosion of the improved seat outlet was significantly reduced, and the system pump pressure difference was reduced from approximately 0.2 MPa to nearly 0 MPa, demonstrating an effective “simulation–manufacturing–field verification” engineering loop.

Finally, regarding energy and signal transmission in extreme high-temperature and high-pressure downhole environments, Yu et al. observed that deep hard rock coring systems urgently need to transition from “only pressure preservation” to “both temperature and pressure preservation”. Achieving active insulation and intelligent control requires reliable downhole power supply and signal transmission, which remains a significant challenge internationally. In response, the authors combined TRIZ’s contradiction resolution mechanism with axiomatic design (AD) system decomposition principles to propose an innovative process mapping functional requirements to structural solutions for the conductive center rod. They clarified key requirements for module alignment, contact conduction, and avoiding wire entanglement to improve the stability and manufacturability of connections and transmission under extreme environmental conditions.

Overall, the results presented in this Special Issue focus on three main areas: the design of intelligent drilling and coring equipment and robotic systems for extreme environments, research on deep in situ environment reconstruction and high-temperature and high-pressure simulation testing platforms, and the enhancement of critical component reliability and multi-physics structural optimization under extreme conditions. These contributions form a complete chain from components to systems, from design to verification, providing a transferable methodological framework and engineering basis for the efficient development and safe operation of equipment in extreme environments, while also advancing the engineering application of intelligent manufacturing in harsh conditions, such as deep earth and deep space. In industrial applications, deep mining and geotechnical engineering can benefit from intelligent support systems and condition-preserved coring and testing platforms, reducing the risks associated with dynamic excavation, enhancing stability management, and obtaining more reliable subsurface properties to support disaster prediction and support design. In the energy exploration sector, the optimization of pressure-preserved coring components and CFD-guided reliability enhancement reduces the risk of failure and improves sample fidelity, thus advancing reservoir evaluation and decision-making. Additionally, laboratory simulation systems reduce reliance on expensive field tests and shorten development cycles, and the fidelity coring analysis of gas hydrates enables the direct quantification of in situ methane, highlighting the value of fidelity sampling in extreme environments. Planetary exploration also benefits from autonomous and human-assisted drilling and coring concepts, which are essential for tasks in environments that are difficult to maintain, with strict limitations on mass and energy. In conclusion, these studies emphasize that the key to deployable intelligence lies in integrating robust design, validation-oriented testing systems, and data-driven optimization into a cohesive workflow, rather than isolated improvements.

3. Conclusions

Overall, the published papers in this Special Issue concentrate on three main areas: (i) intelligent drilling and coring equipment and robotic systems for extreme environments, (ii) deep in situ environment reconstruction and high-temperature/high-pressure simulation testing platforms, and (iii) the reliability enhancement of critical components and multi-physics structural optimization under extreme conditions. Collectively, the contributions form a chain from components to systems and from design to verification, providing methodological elements and engineering evidence for the efficient development and safer operation of equipment in extreme environments—particularly for deep earth and deep space.

From an application perspective, deep mining and geotechnical engineering can benefit from intelligent support systems and fidelity coring/testing platforms to reduce risks in dynamic excavation and improve stability management while enabling more reliable subsurface-property characterization for hazard prediction and support design. In energy exploration, the reliability enhancement and CFD-guided optimization of pressure-preserved coring components can reduce failure risks and improve sample fidelity, strengthening reservoir evaluation and decision-making. In parallel, laboratory simulation systems can reduce dependence on expensive field trials and shorten development cycles. Finally, planetary exploration may benefit from autonomous and human-assisted drilling/coring concepts that address operational constraints under limited mass, energy, and maintainability.

In summary, this Special Issue highlights that deployable intelligence under challenging conditions is most effectively achieved by integrating robust design, validation-oriented testing systems, and data-driven optimization into a cohesive workflow, rather than by isolated incremental improvements. Future research may further focus on the following:

(1)

Enhancing robust autonomy and online adaptability under strongly varying conditions and data scarcity;

(2)

Strengthening closed-loop integration across “design–simulation–testing–deployment”, including deeper coupling between digital twins and physical validation;

(3)

Establishing transferable evaluation metrics and standardized validation protocols to enable reproducible comparisons and scalable engineering deployment.