Search Results (136)

PocketQube-class satellites have emerged as a cost-effective platform for space access; however, their extreme mass, volume, and dimensional constraints challenge conventional manufacturing approaches. This systematic review examines the state of the art of additive manufacturing (AM) for PocketQube structural systems between 2015 and 2026, focusing on materials, manufacturing processes, design methodologies, qualification frameworks, and flight heritage. A PRISMA-guided review methodology combined with a PICO/SPIDER-based selection framework was applied to analyse the peer-reviewed literature, technical standards, and documented mission data. The results indicate that AM has evolved from a prototyping tool into a viable production technology for picosatellite structures, enabling mass reductions of 30–60%, increased geometric complexity, functional integration, and improved packaging efficiency within the 50 × 50 × 50 mm PocketQube envelope. Polymer-based selective laser sintering, particularly Windform XT 2.0, currently represents the highest-maturity solution, while laser powder bed fusion of AlSi10Mg and Scalmalloy^® shows significant potential for future primary structures. The review further identifies a persistent gap between technological maturity and qualification readiness, as existing ECSS, NASA, and ISO/ASTM standards remain insufficiently tailored to PocketQube-class hardware. Future research should prioritise dedicated qualification pathways, in-orbit validation of metallic AM structures, and multifunctional topology-optimised architectures to enable the next generation of ultra-small spacecraft. Full article

This article presents a two-dimensional (2D) computational fluid dynamics (CFD) model of the operating processes in a spool-valve-type orbital hydraulic motor. The model is developed to predict the flow rate and torque characteristics of the hydraulic motor as functions of rotational speed and pressure drop. To reproduce the fluid commutation process in the simplified 2D domain, an equivalent kinematic representation with a rotating shaft-distributor is implemented. An original methodology for torque determination based on the hydrodynamic forces acting on the gerotor is also proposed. The numerical results are validated using both manufacturer catalog data and experimental measurements obtained on a laboratory test rig under identical operating conditions. Good agreement is achieved between the numerical, catalogue, and experimental results. For the experimental validation, the absolute value of the relative flow rate error is within 0.07–3.58%, while the corresponding torque error is within 0.08–13.32%. The results demonstrate that the proposed 2D CFD model can be used to predict the main hydraulic and mechanical characteristics of the investigated hydraulic motor with satisfactory accuracy. Full article

Quartz wafer dicing technologies primarily rely on mechanical cutting and etching processes. Mechanical cutting is easy to generate the micro-cracks along the wafer edges, which compromises component precision. Furthermore, etching processes are associated with long processing times, high manufacturing costs, and environmental concerns. To address these limitations, this study proposes an electrochemical discharge cutting machining (ECDCM) method using a micro-tungsten carbide helical electrode performing orbital circular cutting (OCC) to evaluate the feasibility and optimization of quartz wafer dicing. Experimental studies were conducted to evaluate the effects of applied voltage, pulse duration, Z-axis feed rate, and duty factor on slot width, slot depth, slot surface quality and tool electrode wear. The results demonstrate that employing an OCC of micro-electrode facilitates the efficient flow of electrolyte into the machining zone, thereby enhancing discharge stability and slot quality. Compared to circular path cutting (CPC) with a rotating electrode, the proposed method reduces machining time by nearly four times and decreases material loss during circular quartz wafer cutting by approximately 50%. These findings indicate that the proposed machining approach provides high efficiency and high-quality quartz wafer cutting. Full article

Organic solar cells (OSCs) are a potential photovoltaic technology because they can be manufactured in scalable systems, are lightweight, and have mechanical flexibility. Power conversion efficiencies close to 20% have been achieved in recent years due to the quick development of donor–acceptor material systems. Better control over nanoscale shape and the creation of non-fullerene acceptors are major factors driving this advancement. Nevertheless, there are still complicated connections between morphology, interfacial energetics, and molecular structure. It is yet unclear how these elements interact to affect charge creation and transport. In this review, donor–acceptor interactions in organic solar cells are examined from a fundamental chemical and physical perspective. From conventional fullerene derivatives to contemporary non-fullerene acceptors, we first look at the development of acceptor materials. We demonstrate how molecular engineering has enhanced device efficiency, energy level adjustment, and light absorption. We then examine the energetic alignment at donor–acceptor interfaces, paying particular attention to charge-transfer state creation, border orbital offsets, and the factors influencing voltage losses. We also investigate how intermolecular interactions, including hydrogen bonding, π-π stacking, and noncovalent interactions involving heteroatoms, control electrical coupling and nanoscale shape in bulk heterojunction active layers. We also go over device engineering techniques including processor control, interface engineering, and bulk heterojunction architecture optimization. These tactics demonstrate how improved solar performance might result from molecular design. Lastly, we highlight new possibilities for next-generation OSCs, such as scalable production techniques, adaptive molecular design, and morphological stabilization. This work provides a strong framework for comprehending donor–acceptor interactions and for directing the careful design of high-performance organic photovoltaic systems by combining knowledge from molecular chemistry, morphological control, and device engineering. Full article

Low-Earth-orbit (LEO) megaconstellations are transforming satellite communications from sparse, ground-controlled infrastructures into dense, dynamic, and increasingly autonomous space networks, while their global coverage capability is fundamentally enabled by large-scale symmetric orbital structures distributed across multiple planes and shells. As these systems expand to tens of thousands of satellites, maintaining such orbital symmetry under continuous perturbations, changing communication topologies, and varying onboard resources becomes a fundamental operational challenge. Future space systems must therefore manage, coordinate, and sustain large constellations for which their orbital configurations, communication topologies, and onboard resources vary continuously. Here, we review the management and configuration-maintenance problems of megaconstellations through a Starlink-informed perspective. We first summarize the multi-shell deployment architecture, satellite platform evolution, and dominant orbital perturbations that shape constellation behavior. We then examine hierarchical and cluster-based management strategies designed to reduce the burden on ground control and improve scalability. We further discuss in- and out-of-plane configuration maintenance. Finally, we identify open challenges in distributed autonomy, multi-shell coordination, dynamic topology management, and intelligent orbit control. This review highlights that the long-term viability of megaconstellations will depend not only on launch capacity and satellite manufacturing but also on scalable decision-making, autonomous coordination, and sustainable orbital operations. Full article

Background: High-technology supply chains are interdependent logistics infrastructures in which digital, energy, manufacturing, cloud and orbital layers are tightly coupled. This paper examines how such layering changes supply chain resilience and systemic vulnerability. Methods: The paper develops an analytical–conceptual framework linking supply chain resilience, interdependent infrastructure theory and network topology. It introduces Topological Phase Vulnerability (TPV), capturing proximity to structural fragility thresholds, and the Shock Amplification Coefficient (SAC), conceptualizing disruption amplification as a function of centrality concentration, cross-layer coupling and reconfiguration capacity. The framework is supported by a fuzzy-inspired diagnostic scorecard and stylized assessment of alternative infrastructure configurations. Orbital computing is an extreme illustrative context because it combines dependence on advanced semiconductor fabrication, hyperscale cloud orchestration, energy systems, launch capacity and logistics coordination. Results: Highly centralized configurations are more likely to transform local disruptions into cross-layer cascades, whereas modular and distributed configurations are more likely to contain disruption through redundancy, substitutability and rerouting. Conclusions: Resilience in next-generation logistics infrastructure depends not only on capacity or component reliability, but also on topology. Centrality dispersion, modularity and reconfiguration capacity are critical design principles for reducing shock amplification in high-technology supply chains. Full article

During the 9th NASA MISSE (Materials International Space Station Experiment) campaign, a multilayer LDPE-based shield was tested in a low Earth orbit (LEO) environment aboard the International Space Station for the first time, in the wake-facing orientation. The architecture of the multilayer flight sample, 1 inch in diameter, consisted of two external LDPE sheets and two inner layers filled with boron nitride and samarium–cobalt powders. The inner layers were manufactured using an original process based on compression molding of two superimposed LDPE sheets, with the functional filler deposited onto one of them by spray coating. Thanks to the partial filling of the inner layers and their relative positioning, four different shielding configurations were obtained. The sample was exposed to the space environment for approximately 200 days, experiencing the combined effects of vacuum, solar radiation, thermal cycling, and limited atomic oxygen exposure. The results show that the structural integrity of the shield was not affected by its prolonged residence in LEO. The most significant effect observed was the partial oxidation of the external surfaces of the individual layers, particularly the uppermost layer. Full article

The deployment of CubeSats requires reliable, lightweight, and space-efficient launch mechanisms. Traditional spring-based deployers often rely on standard off-the-shelf components, limiting the design flexibility. This study presents a pilot design-to-verification workflow for a CubeSat deployment mechanism manufactured by Laser Powder Bed Fusion from 316L stainless steel. The workflow integrates analytical sizing, kinematic and numerical force assessment, FEM-based LPBF process simulation employed as a design-support tool to predict thermal displacements and residual stress that occur during manufacturing, prototype manufacturing and optical inspection. Optical scanning indicated that the main envelope dimensions remained close to the nominal CAD values, while the support-plate warping was localized at the plate corners due to the residual thermal stress after the support removal. The study validates the manufacturability of a single LPBF orbital-deployer lunch mechanism and assesses its dimensional accuracy and workflow feasibility, rather than its functional mechanical performance. It also includes mitigation strategies for deployer distortions. Full article

The orbital space ecosystem is undergoing significant change, with numerous initiatives focused on in-orbit services, assembly, and manufacturing. These initiatives are being developed globally, with ongoing studies in America, Asia, and Europe. As these technologies evolve, questions arise about their compatibility and interoperability, especially for long-term in-orbit operations. The Space USB project addresses these challenges by aiming to connect European partners involved in the emerging interconnection systems market for in-orbit services. Its goal is to improve the compatibility and interoperability of these systems across Europe, with perspectives for broader international application. As part of this project, a prototype has been developed to connect with the interconnection systems of three European partners. A test campaign was conducted to assess the prototype’s functionality, using a robotic system. Full article

This paper presents a systematic qualification process for an electronic beam-steering antenna assembly for a low-Earth orbit (LEO) communication satellite. The transmitting/receiving antenna for the LEO communication satellite is based on a cavity-backed slot radiator, which has improved radiation efficiency and low mutual coupling compared to conventional PCB patch structures. In order to verify the electrical performance and reliability of the manual soldering process in a tightly spaced array structure with narrow element spacing and densely connected multi-channel RF modules, a reduced model was designed and fabricated and qualification tests were conducted under launch and on-orbit environments. The integration equipment was developed to ensure precise mechanical alignment and integration/disassembly between the radiating element arrays of the transmitting and receiving antenna modules and the RF modules, thereby establishing a manufacturability strategy for the antenna module and RF integrated module, which comprise a large array structure. Finally, the qualification tests of the transmitting and receiving antenna were performed to evaluate the structural and thermal stability considering the launch and orbital environments. The systematic qualification process proposed in this paper can be used in the development of the antenna system of the communication satellite. Full article

A software autonomy framework provides a vital solution to the challenges posed by growing congestion in Earth’s orbits and the increasing complexity of planetary exploration. For satellite constellations, IOS & ISAM missions, autonomy minimizes dependence on ground control by enabling real-time decision-making for spacecraft collision avoidance, client capture, robotic servicing operations, resource optimization, and resilience against cyber threats in a crowded and geopolitically sensitive space environment. Similarly, autonomous frameworks allow rovers to operate efficiently on distant planets, where communication delays make manual control impractical. By integrating adaptive navigation, fault management, and cooperative behaviors, these systems enhance mission success, reduce operational costs, and ensure rapid responses to dynamic conditions, both in orbit and on planetary surfaces. This paper presents the ERGO Autonomy SW Framework as a mature solution to deal with these space challenges. Full article

In this study, an on-site installation type track slab using glass fiber-reinforced polymer (GFRP) reinforcing bars was developed and analyzed for its structural response to high-speed train loading. Concrete track slabs have the most severe deterioration in track circuit characteristic values due to the conduction influence of existing steel bars. Therefore, a track slab applying an insulator and lightweight GFRP reinforcement by replacing the existing steel bar was proposed from a design perspective. In order to present the validity of the proposed method, a full-size specimen was manufactured and a structural performance test was conducted, and the results were compared and verified through three-dimensional numerical analysis. The results showed that the new orbital slab applying the GFRP reinforcement has satisfactory insulation and provides sufficient structural performance that can replace the existing steel bar. Full article

This paper presents a modular Power Conditioning and Distribution Unit (PCDU) designed for small satellites. The proposed system features a highly adaptable architecture capable of managing a total power throughput of up to 100 W, with specific limits defined by mission-dependent thermal and redundancy configurations. Aligned with the New Space paradigm, the implementation relies on Commercial Off-The-Shelf (COTS) components, a strategy that drastically reduces development and manufacturing costs without compromising reliability. The system has been optimized for operation in harsh environments, including high vacuum, ionizing radiation, and extreme thermal gradients. The design incorporates strict redundancy and fault-tolerance criteria to provide a robust solution for critical subsystems. Comprehensive validation was performed through functional testing, Total Ionizing Dose (TID) radiation campaigns, and Thermal Vacuum (TVAC) cycles. Experimental results demonstrate that the PCDU withstands high-vacuum thermal cycling and cumulative radiation doses exceeding 75 kRad. These findings confirm that the developed unit is a cost-effective, high-reliability solution suitable for both Low Earth Orbit (LEO) and deep-space missions. Full article

Wide-swath longwave infrared (LWIR) imaging from Low Earth Orbit (LEO) demands fast optics and rectilinear (F-tan) mapping for thermal mapping and multi-frame registration. Achieving an F/1.2 aperture with a 112° diagonal field of view (FOV) and distortion within ±5% is challenging, as mapping constraints and field-dominant off-axis aberrations become strongly coupled at large chief-ray angles. The low-distortion target is not only a geometric specification, but also a practical requirement that reduces peripheral compression, helps maintain edge-detail consistency, and lowers digital de-warping effort in the processing pipeline. While traditional LWIR secondary imaging is predominantly restricted to narrow-field cooled systems for cold-stop constraints, the proposed architecture utilizes a curved intermediate image to effectively decouple mapping formation in the field-dominant front objective from aperture-dominant correction in the rear group. Using chalcogenide glasses, the lens achieves a 5.7 mm effective focal length within a 186.9 mm total track. Analysis over the 8–12 μm band confirms performance approaching the diffraction limit at the 50 lp/mm Nyquist frequency alongside stable geometric fidelity across the full field. Thermal analysis from −40 °C to 80 °C and Monte Carlo tolerance analysis demonstrate stable imaging performance and manufacturing feasibility, confirming the effectiveness of the proposed design approach. Full article

Photopolymer-based additive manufacturing processes such as stereolithography (SLA) offer high precision and surface quality but generate cured thermoset waste that is typically non-recyclable. In microgravity environments, conventional recycling approaches—based on gravitational settling, open solvent handling, and buoyancy-driven degassing—are ineffective, motivating the development of fully contained, gravity-independent material recovery systems for on-orbit manufacturing. This work presents a conceptual, design-stage closed-loop system architecture for recycling photopolymer resins in microgravity. The system integrates eight subassemblies enabling mechanical fragmentation, solvent-assisted dissolution, filtration, low-pressure degassing, pressurized storage, injection molding, and ultraviolet curing. A hermetically sealed dual-screw shredder produces resin fragments of 1–3 mm, suitable for dissolution. Gas removal is achieved through low-vacuum degassing at approximately 0.1–0.3 bar, with characteristic residence times of 5–10 min, ensuring stable processing prior to injection. Material transport is governed by mechanical conveyance and controlled pressure, eliminating reliance on gravity. The architecture maintains full containment of solids, liquids, and vapors throughout the process. Supported by engineering design considerations, the system establishes a microgravity-compatible pathway for closed-loop recycling of SLA materials. Experimental validation is planned in future work. Full article