Since the first successful on-orbit repair mission in 1984 to the Solar Maximum Mission (SMM) satellite, considerable progress has been made in the field of On-orbit Servicing, Assembly, and Manufacturing (OSAM) of spacecraft using either human-guided or autonomous robots. This article aims to provide a review of state-of-the-art efforts in this field and the necessary technologies to achieve the ultimate objective of autonomous spacecraft repairs while in orbit. The article covers the literature relevant to OSAM, including a brief overview of OSAM, inspection technologies, manufacturing and repair technologies, state-of-the-art robotic technologies capable of performing the required tasks, and intelligent path planning of robots. The article also highlights the research’s location, timeframe, and public versus private sector efforts, and outlines future directions in this field. This article aims to foster a community of researchers and public-private partnerships working towards the common objective of autonomous robotic inspection and repair of on-orbit spacecraft.

Advances in sensing technologies are increasingly transforming cutting operations by enabling data-driven condition monitoring, predictive maintenance, and process optimization. This review surveys recent developments in sensing modalities for cutting systems, including vibration sensors, acoustic emission sensors, optical and vision-based systems, eddy-current sensors, force sensors, and emerging hybrid/multi-modal sensing frameworks. Each sensing approach offers unique advantages in capturing mechanical, acoustic, geometric, or electromagnetic signatures related to tool wear, process instability, and fault development, while also showing modality-specific limitations such as noise sensitivity, environmental robustness, and integration complexity. Recent trends show a growing shift toward hybrid and multi-modal sensor fusion, where data from multiple sensors are combined using advanced data analytics and machine learning to improve diagnostic accuracy and reliability under changing cutting conditions. The review also discusses how artificial intelligence, Internet of Things connectivity, and edge computing enable scalable, real-time monitoring solutions, along with the challenges related to data needs, computational costs, and system integration. Future directions highlight the importance of robust fusion architectures, physics-informed and explainable models, digital twin integration, and cost-effective sensor deployment to accelerate adoption across various manufacturing environments. Overall, these advancements position advanced sensing and hybrid monitoring strategies as key drivers of intelligent, Industry 4.0-oriented cutting processes.

This study presents the design and simulation of a four‐legged mobile robot engineered for autonomous navigation on the exterior surface of a spacecraft hull. Unlike existing space robotic systems that rely on fixed infrastructure or operate in structured environments, this quadruped robot is designed to traverse complex, nonplanar hull geometries without external support. The robot integrates global path planning using Dijkstra’s algorithm with real‐time orientation correction via an onboard MPU‐6050 IMU, enabling it to align with waypoints and minimize positional drift during movement. To evaluate performance, a 2D representation of a spacecraft hull was used, and three test runs were conducted. The robot demonstrated the ability to follow the computed optimal path with a positional deviation of less than 0.5% by the third trial. Positional error was quantified per waypoint and summarized using average and standard deviation metrics, while total traversal distances ranged from 65.50 to 63.00 in., approaching the theoretical minimum of 62.70 in. These results highlight the robot’s iterative improvement in trajectory tracking and its potential for future use in autonomous on‐orbit servicing and spacecraft inspection applications.

Geckos achieve exceptional adhesion through hierarchical micro/nanoscale setae exploiting van der Waals forces, a mechanism challenging to replicate synthetically due to fabrication complexity. This study presents a cost‐effective, lithography‐free method for gecko‐inspired adhesives by casting PDMS onto commercial diffraction‐grated sheets. The resulting microstructure exhibits directional adhesion, passive detachment, and a non‐adhesive default state. Shear and peel tests across 8.06–103.23 cm ² contact areas demonstrated a maximum shear stress of 19.10 kPa (supporting up to 7.105 kg) and peel forces below 1 N at 90°, confirming controlled release. Durability testing showed performance recovery after contamination and cleaning, ensuring reusability. The fabrication method eliminates cleanroom requirements, using RTV silicone, 3D‐printed fixtures for rapid, scalable prototyping, and diffraction‐grated molds. Current limitations include single‐level microstructures and absent nanoscale features, reducing efficacy on varying surface structures. Future work will integrate resin‐printed molds to introduce wedge‐shaped/angled structures and microporous filters for nanoscale fidelity, aiming to develop hierarchical adhesives that rival state‐of‐the‐art systems. These advancements target high performance while maintaining affordability and scalability for diverse applications, from robotics to industrial automation. By bridging the gap between biological inspiration and manufacturable design, this approach offers a practical pathway toward reusable, high‐capacity adhesives with broad real‐world utility.

Ureteroscopy with stone extraction devices is a common treatment for urolithiasis but carries risks, such as ureteral wall avulsion due to excessive withdrawal forces. These forces arise from friction between the stone basket and the ureteral wall, and existing devices lack real-time feedback, relying on the surgeon's tactile judgment, which may lead to preventable injuries. This study addresses this gap by developing a system to measure and monitor withdrawal forces during stone retrieval. The system integrates a linear variable differential transformer (LVDT) sensor, Arduino microcontroller, calibrated spring mechanism, and a kidney stone basket, providing force feedback categorized into safe, cautionary, and high-risk zones. Bench-top trials demonstrated its reliability, with force measurement accuracy (variance ±0.05 N) and classification into safe (9.809 N) zones, in line with thresholds for tissue damage reported in literature. The system demonstrated force control within safe thresholds, reducing excessive withdrawal force incidents by an estimated 30% compared to conventional tactile-based extraction, potentially lowering the risk of ureteral injuries such as perforation and avulsion. Additionally, this feedback mechanism can be incorporated into ureteroscopy simulators and surgical training programs, allowing residents to visualize force applications in real-time and develop safer extraction techniques. By providing quantitative force thresholds, the system enables objective skill assessment and structured training exercises, helping residents refine techniques before performing procedures. Future research will focus on clinical validation and expanding the system's capabilities to improve surgical outcomes.

Gecko-inspired adhesives offer strong, reversible, and directionally tunable adhesion, yet fabrication methods often depend on cleanroom lithography or proprietary molds, limiting scalability and accessibility. This study presents a low-cost, modular fabrication strategy combining high-resolution digital light processing (DLP) 3D printing with 1,000 lines/mm optical diffraction gratings to create hierarchical elastomeric adhesives. The resulting structures feature macroscale micropillars and embedded sub-micron surface topography, enabling effective contact splitting without advanced microfabrication. Mechanical testing reveals a nonlinear increase in shear performance with contact area, with maximum shear forces exceeding 80 N at 103.2 cm². Peel testing across varied angles and surface areas demonstrates anisotropic adhesion, with peak peel strength of 21.94 N and detachment energy of 3.88 J/m^2 at a 30° peel angle for patch area of 103.2 cm². A comparative cost analysis highlights the accessibility of this method, revealing a 10–100x reduction in fabrication cost relative to cleanroom and roll-to-roll-based techniques. This approach enables reproducible microstructure transfer, optical validation, and application-specific tunability, offering a practical, scalable pathway for bio-inspired adhesives in robotics, wall-climbing systems, and soft interface applications.