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The purpose of this paper is to investigate the effect of the main process parameters of laser melting (LM) type additive manufacturing (AM) on multi-layered structures manufactured from JSC-1A Lunar regolith (Moondust) simulant powder.

Laser diffraction technology was used to analyse and confirm the simulant powder material particle sizes and distribution. Geometrical shapes were then manufactured on a Realizer SLM™ 100 using the simulant powder. The laser-processed samples were analysed via scanning electron microscopy to evaluate surface and internal morphologies, X-ray fluorescence spectroscopy to analyse the chemical composition after processing, and the samples were mechanically investigated via Vickers micro-hardness testing.

A combination of process parameters resulting in an energy density value of 1.011 J/mm² allowed the successful production of components directly from Lunar regolith simulant. An internal relative porosity of 40.8 per cent, material hardness of 670 ± 11 HV and a dimensional accuracy of 99.8 per cent were observed in the fabricated samples.

This research paper is investigating the novel application of a powder bed fusion AM process category as a potential on-site manufacturing approach for manufacturing structures/components out of Lunar regolith (Moondust). It was shown that this AM process category has the capability to directly manufacture multi-layered parts out of Lunar regolith, which has potential applicability to future moon colonization.

The purpose of this paper is to evaluate the feasibility of direct fabrication of lunar/Martian regolith simulant parts, in a freeform environment, using Laser Engineering Net Shaping (LENS™) – an additive manufacturing technology.

Bulk lunar regolith simulant structures were fabricated using a LENS™‐750. Dense parts without any macroscopic defects were produced at a laser power of 50W, a scan speed of 20 mm/s, and a powder feed rate of 12.36 g/min. The laser processed parts were characterized using X‐ray diffraction, differential scanning calorimetry, scanning electron microscope and X‐ray photoelectron spectroscopy to evaluate the influence of laser processing on the microstructure, constituent phases and chemistry of lunar regolith simulant.

A combination of laser parameters resulting in a 2.12 J/mm² laser energy appeared to be ideal for generating a melt pool necessary for lunar regolith powder deposition without excessive liquid pool spreading and cracking of solidified parts. The results show that LENS™ based laser processing transformed crystalline regolith into nanocrystalline and/or amorphous regolith structures as a result of complete melting followed by resolidification. Laser processing also resulted in marginal changes in the composition of the regolith.

Establishment of a lunar/Martian outpost necessitates the development of methods to utilize in situ mineral resources for various construction and resource extraction applications. Fabrication technologies are critical for habitat structure development, as well as repair and replacement of tools and parts at the outpost. Current experimental results presented in the paper clearly demonstrate that net shape regolith simulant parts can be fabricated using LENS™ by exploiting its capabilities.

Retained excavation is important for future lunar exploratory missions and potential human colonization that requires the construction of permanent outposts. Knowledge in excavation obtained on the Earth is not directly applicable to lunar excavation because of the low lunar gravity and the non-negligible adhesive van der Waals interactions between lunar regolith grains. This study aims at revealing how the gravity level and lunar environment conditions should be considered to extend the knowledge in Earth excavation response to lunar excavation.

Two-dimensional Discrete Element Method (DEM) simulations were carried out to investigate the respective effect of gravity level and lunar environment conditions (high vacuum and extreme temperature) on retained excavation response. A novel contact model was employed with a moment – relative rotation law to account for the angularity of lunar soil particles, and a normal attractive force to account for the van der Waals interactions.

The simulation results showed that the excavation response is non-linearly related to the gravity level. Van der Waals interactions can increase the dilatancy of lunar regolith and, surprisingly as a consequence, significantly increase the bending moment and deflection of the retaining wall, and the ground displacements. Based on the simulation results, a parabola model was proposed to predict the excavation induced lateral ground movements on the Moon.

This study indicates that an unsafe estimate of the wall response to an excavation on the Moon would be obtained if only the effect of gravity is considered while the effect of van der Waals interactions is neglected.

A major obstacle regarding the measurement of an organization's sustainability and accountability in the space economy is defining the context and boundaries of commercial activity in outer space. Here, we introduce an ecosystem framework to address this obstacle. We utilize this framework to analyze the space mining sector. Our ecosystem framework sets the space mining sector's boundaries and helps a firm identify key stakeholders, activities, policies, norms and common pool resources in that sector and the interactions between them; a significant step in structuring how to measure space sustainability and accountability.

Borrowing theories and perspectives from a wide range of academic fields, this paper conducts a comprehensive context analysis of the space mining ecosystem.

Using our ecosystem framework to define the context and set boundaries for the space mining sector allowed us to identify sustainability-related issues in the sector and offer roadmaps to develop sustainability measures and standards.

To the best of the authors’ knowledge, this is one of the first papers to introduce a framework to define boundaries in the global space economy and provides a tool to understand, measure and evaluate the space mining sector's environmental, social and economic issues.

The purpose of this paper is to present an investigation of the effect of different gravity conditions on the penetration mechanism using the two-dimensional Distinct Element Method (DEM), which ranges from high gravity used in centrifuge model tests to low gravity incurred by serial parabolic flight, with the aim of efficiently analyzing cone penetration tests on the lunar surface.

Seven penetration tests were numerically simulated on loose granular ground under different gravity conditions, i.e. one-sixth, one-half, one, five, ten, 15 and 20 terrestrial gravities. The effect of gravity on the mechanisms is examined with aspect to the tip resistance, deformation pattern, displacement paths, stress fields, stress paths, strain and rotation paths, and velocity fields during the penetration process.

First, under both low and high gravities, the penetration leads to high gradients of the value and direction of stresses in addition to high gradients in the velocity field near the penetrometer. In addition, the soil near the penetrometer undergoes large rotations of the principal stresses. Second, high gravity leads to a larger rotation of principal stresses and more downward particle motions than low gravity. Third, the tip resistance increases with penetration depth and gravity. Both the maximum (steady) normalized cone tip resistance and the maximum normalized mean (deviatoric) stress can be uniquely expressed by a linear equation in terms of the reciprocal of gravity.

This study investigates the effect of different gravity conditions on penetration mechanisms by using DEM.

This paper sets out to discuss a proposal for power generation by atomic fusion using the helium isotope of mass 3, obtained from the moon, and to compare it with the better‐known proposed method using deuterium and tritium. It proposes to discuss a new trend by which computing power is made available “on tap” rather than in individual users' installations.

The aim is to review developments on the internet, especially those of general cybernetic interest.

The possibility of fusion power based on helium‐3 should be kept in mind, but is subject to numerous difficulties. Centralized computing offers a number of benefits and is a current trend.

Fusion power from helium‐3 is a remote and uncertain possibility, and attention should not be diverted from efforts to reduce carbon emissions and global warming by other means. Large‐scale users of computers might well consider subscribing to a central service.

It is hoped that this will be a valuable periodic review.

The purpose of this paper is to present an introduction to geometric conformity principles for examining the geometric deviation between the desired (designed) and the fabricated surfaces which may be generated by a class of surface ruling fabrication processes such as flank milling, wire electrical discharge machining (WEDM), and contour crafting (CC).

In general, it is computationally challenging to calculate error approximation based on points. This paper proposes methods that efficiently calculate error approximation based on curve, surface area, and volume.

This paper derives the equations for calculating the ruled surface areas and the volume of 3D slices in 3D object models. One may use the difference of surface areas or volumes to determine the extent of the global conformity of the ruled surfaces. Additionally, local conformity analysis through calculating curve deviation has been introduced to improve the reliability of the global conformity analysis.

The research results apply only to fabrication processes that generate ruled surfaces. There are, however, numerous applications in which ruled surfaces are generated, such as WEDM, any numerical control machining which uses cylindrical or conical cutting bits, and CC.

The research results presented will be applicable to fabrication processes such as flank milling, WEDM, and CC.

All developments presented are original. Also, CC, which is a candidate process for the developments presented in the paper, has been invented and developed by the authors.

The purpose of this study is to investigate a new and innovative sandwich material evaluating its capability for use in space habitat structural components in deployable and foldable configurations. The main habitat requirements were considered in the preliminary design of a typical space outpost, proposing a preliminary architecture.

The stiffness properties of the innovative sandwich (MAdFlex ®) were evaluated using numerical and experimental investigations. Four-point bending tests were performed for complete sandwich characterization. Numerical FE simulations were performed using typical material properties and performance. The application to a space habitat main structure as a basic material has also been discussed and presented.

MAdFlex basic stiffness performances have been determined considering its double behavior: sufficiently stiff if loaded in a specific direction, flexible if loaded in the opposite direction and enhanced folding performance. Successful application to a typical space habitat confirms the validity and convenience of such a material in designing alternative structures.

The innovative material demonstrates wide potential for structural application and design in demanding space situations under operating conditions and in stored ones at launch.

Several simple deployable structural components can be designed and optimized both for the space environment and for the more traditional terrestrial applications.

Simplification in structural design can be derived from deployable low-weight items.

Innovative customized material in sandwich configuration has been proposed and investigated with the aim to demonstrate its potentiality and validity in alternative design architecture.

The purpose of this paper is to study the path optimization method of the manipulator in the lunar soil excavation and sampling process. The current research is a practical need for the excavation and sampling of the lunar soil in the lunar exploration project.

This paper proposes the objective function and constraints for path optimization during the excavation process of the lunar soil, regarding excavation time and energy consumption as the two key fitness indexes by analyzing the whole excavation process of the lunar soil. Specifically, the optimization is divided into two consecutive phases, one for the excavation path and the other one for joint motions. In the first phase, the Bézier polynomial is adopted to get the optimal excavation angle and reduce energy consumption. In the second phase, a method based on convex optimization, variable conversion and dynamic process discretization, is used to reduce excavation time and energy consumption.

Controlled experiments on the fine sand and the simulant lunar soil were conducted to verify the feasibility and effectiveness of the two phases of the optimization method, respectively.

The optimization method of the excavation tasks in this paper is of great value in theoretical and practical engineering, and it can be applied in other robotic operational tasks as well.

To trace a shift in attitudes towards control since the mid-twentieth century, as reflected in a shift in rhetoric that accompanied the extension from first- to second-order cybernetics.

Narratives of exploration that have emerged from NASA’s lunar programme and recent design cybernetics are juxtaposed to show a transition away from the legitimisation of goal-oriented decision-making and control towards advocacy of partial control avoidance and accommodation of the unanticipated.

Contemporary cybernetic theory recognises the importance of both the partial presence and the partial absence of control in creative epistemic practice. It is thus unsurprising that, according to historical records, NASA’s journey to the moon was enabled not only by the assurance of control but also by lapses of control. However, NASA’s rhetorical posture during the race to the moon focused on predictable control and goal orientation, differing notably from the recent design-cybernetic openness towards uncertainty, error, and serendipity. This difference is encapsulated by the “Failure is not an option” dictum that was associated with NASA’s lunar programme and the “Try Again. Fail Again. Fail Better” equivalent associated with design cybernetics. Recognition of the more recent cybernetic perspective is impeded by its continuing omission from narratives of earlier cybernetic accomplishments.

To the extent that narratives examined in this paper refer to exceptional initiatives and spontaneous events, the repeatability and generalisability of the presented argument are limited.

The paper highlights changing cybernetic narratives of creative invention by examining how spontaneous changes in variety were reported to have been addressed in NASA’s lunar programme, and how recent cybernetic design theory suggests they should be addressed.