Dr Sungwoo Lim

MARVEL (Microwave heating Apparatus for Regolith Variant Experiments for Lunar ISRU) is a collaborative project between the Open University, Added Value Solutions UK Ltd. and VIPER RF. The team has been developing the Microwave Heating Demonstrator (MHD) payload [1,2] since 2019 with the ambition to perform pre-defined experiments on the Moon, which explore the potential of microwave heating-based 3D printing for developing a lunar construction process and in-situ resource extraction. The final goal of the MARVEL project is to support ESA’s Terrae Novae 2030+ strategy roadmap for the Moon, particularly for the large surface habitat and ISRU pilot plant & excavation missions. The initial concept development of the MHD payload was completed with support from UKSA’s NSTP GEI (GEI2-037), Pathfinder (PF3-090), Space Exploration Technology (UKSAG21_0088), and ESA’s Off-Earth Manufacturing and Construction Campaign (4000133998/21/NL/GLC). We have completed another follow-on project funded by UKSA (USAG22_0046D) for 15 months (December 2022 - February 2024) to manufacture a barebone system of the MHD payload for validating/evaluating the microwave cavity’s heating performance (Figure 1 [3]). In this presentation, we will report significantly updated subsystems of the MHD payload and the preliminary testing on the barebone system, including the microwave cavity and the 250 W Solid-State Microwave Generator.

The use of space resources will play a vital role in sustaining a permanent human presence on the lunar surface. In Situ Resource Utilisation (ISRU) is expected to underpin the sustainability of such current and future missions. Water ice at the lunar poles in Permanently Shadowed Regions (PSRs) could provide a source of water for habitat replenishment or as rocket propellant. The water ice in PSRs is likely to be preserved at < 110 K and at least at one polar location, it has been directly measured at 5.6 ± 2.9 wt. % [1], [2]. Rocket propellant can be used to resupply satellites in cislunar space and transport crew and cargo from the lunar surface [3]. The exact nature of water ice stored at PSRs is currently unknown; however, it is likely to be mixed with the local regolith. Thus, finding a technique that maximises the water ice extraction as quickly as possible will be crucial given the harsh conditions present in a PSR (no direct solar irradiation, < 110 K, vacuum conditions). Previous work has found microwave heating to be an efficient technique for extracting water ice from icy lunar simulants [4], [5]. This work presents further microwave heating experiments where, through the use of a Dynamic Mass Instrument (DMI), unique features in the mass loss profiles of Diffuse Icy Regolith (DIR) and Granular Icy Regolith (GIR) were identified. These unique features infer where and for how long microwave heating is an effective water extraction technique.

Space Architecture is the theory and practice of designing and building an extraterrestrial environment for human habitation. It combines engineering and aesthetics, requiring knowledge of space environments, space systems engineering, and the psychology of isolated and confined environments. Over the last decade, Space Architecture has become an emerging issue for future space exploration, and is increasingly seen as a fundamental requirement for supporting long-term space exploration and settlement on other planets.

This paper discusses the relationship between design and economic growth. The top five and lowest five design ranking countries are analysed based on the following five criteria: (1) design, (2) capacity for innovation, (3) extent of branding, (4) business competitiveness and (5) current competitiveness, to identify the relationship. In addition, the importance and influence of design policy and strategy on organisations have been briefly discussed. Finally, anticipated research opportunities to increase design competitiveness are identified and discussed.

This paper develops a formal approach to investigate the evolution of a Korean traditional pattern, Bosangwhamun. The approach employs the structure of symbolic memes embedded in the pattern as a framework of hierarchical decomposition of a pattern to describe an evolutionary development process of a given pattern with a set of rules in shape grammar as style changes. Further, the formal descriptions of the given pattern become the basis for generating its variations. With this process, the validity of the rules and their appropriateness in the representation of Bosangwhamun are examined.

At the Moon, the regolith (soil) is a readily available resource, which can be thermally treated for extracting oxygen and water, as well as, for fabricating construction components. Due to the volumetric heating characteristic, intrinsic to microwave heating, it is considered as a more energy-efficient process than solar or laser sintering for large- scale manufacturing and construction purposes. Proof of concept experiments and numerical modelling have demonstrated that microwaves couple efficiently with lunar regolith simulants. Therefore, microwaves could be an efficient mechanism to sinter and melt lunar regolith to build 3D-printed structures, while also enabling the extraction of volatiles. In the context of In-Situ Resource Utilisation (ISRU) to offset the need to transport all materials from Earth, it is highly desirable and timely to align with the current Solar System exploration road maps of international space agencies. At the Open University, we have been leading the development of a microwave heating-based 3D printing technique to be used as a preferred fabrication method in extra-terrestrial construction processes and resource extraction, including oxygen, water and iron. As part of this research, a series of experiments were conducted to understand the microwave sintering/melting behaviour of lunar regoith and simulants. In this contribution, we describe different microtextures that were observed in microwave heated lunar simulant JSC-1A specimens under different input powers. This is important because it would allow us to utilise a specific input power of microwave for specific applications.

Lunar regolith could be thermally treated to extract resources and build an outer habitat shell using additive manufacturing techniques (a.k.a. 3D printing) by robots [1]. Proof of concept experiments has demonstrated that microwaves couple efficiently with lunar regolith and sinter/melt it to build 3D structures and enable resource extraction [2]. However, there are still several questions that can only be answered through experiments on the Moon surface. Thus, the Open University (OU) initiated a collaborative project MARVEL (Microwave heating Apparatus for Regolith Variant Experiments for Lunar ISRU), with Added Value Solutions UK Ltd. and VIPER RF. The team aims to prepare the groundwork for the UK to lead the development of a Microwave Heating Demonstrator (MHD) payload on future missions to the Moon with the flight hardware being developed and built in the UK. The initial concept development of the MHD payload was completed with support from UKSA?s NSTP GEI funding (Figure 1 [3]). In this presentation, we will report the current progress of the MHD development conducted through the NSTP Pathfinder grant, focusing on the challenges with cavity design and the concept of a 1 kW solid-state microwave generator that could be used for future lunar missions.

The induction of a NURBS freeform surface from an on-line sketch is presented in this paper. This work supports the inference of 3D geometry based on input 2D freehand sketches to support conceptual design. A multi-layer Perceptron (MLP) artificial neural network (ANN) was designed by a series of experiments and implemented to learn the relationship between input sketches and their expected 3D geometry. Experimentation was used to determine the optimal parameters and network architecture. The input data took the format of four constrained boundary strokes and after the ANN had inferred the 3D shape, a complete NURBS serface was generated using an interpolation algorithm.

This paper presents research that aims to inform the development of computational tools that better support design exploration and idea transformation - key objectives in conceptual design. Analyses of experimental data from two fields - product design and architecture - suggest that the interactions of designers with their sketches can be formalised according to a finite number of generalised shape rules defined within a shape grammar. Such rules can provide a basis for the generation of alternative design concepts and they have informed the development of a prototype shape synthesis system that supports dynamic reinterpretation of shapes in design activity. The notion of 'sub-shapes' is introduced and the significance of these to perception, recognition and the development of emergent structures is discussed. The paper concludes with some speculation on how such a system might find application in a range of design fields.

Sketches, with their flexibility and suggestiveness, are in many ways ideal for expressing emerging design concepts. This can be seen from the fact that the process of representing early designs by free-hand drawings was used as far back as in the early 15th century [1]. On the other hand, CAD systems have become widely accepted as an essential design tool in recent years, not least because they provide a base on which design analysis can be carried out. Efficient transfer of sketches into a CAD representation, therefore, is a powerful addition to the designers' armoury. It has been pointed out by many that a pen-on-paper system is the best tool for sketching. One of the crucial requirements of a computer aided sketching system is its ability to recognise and interpret the elements of sketches. 'Sketch recognition', as it has come to be known, has been widely studied by people working in such fields: as artificial intelligence to human-computer interaction and robotic vision. Despite the continuing efforts to solve the problem of appropriate conceptual design modelling, it is difficult to achieve completely accurate recognition of sketches because usually sketches implicate vague information, and the idiosyncratic expression and understanding differ from each designer.

Generalising knowledge and matching patterns is a basic human trait in re-using past experiences. We often cluster (group) knowledge of similar attributes as a process of learning and or aid to manage the complexity and re-use of experiential knowledge [1, 2]. In conceptual design, an ill-defined shape may be recognised as more than one type. Resulting in shapes possibly being classified differently when different criteria are applied. This paper outlines the work being carried out to develop a new technique for shape clustering. It highlights the current methods for analysing shapes found in computer aided sketching systems, before a method is proposed that addresses shape clustering and pattern matching. Clustering for vague geometric models and multiple viewpoint support are explored.

The Space Instrumentation Group at The Open University is investigating microwave sintering of lunar regolith/simulant as a potential fabrication method of 3D printing on the Moon to build lunar habitats. This has enabled us to integrate our existing expertise in 3D Concrete Printing and knowledge of lunar science and ISRU potential on the Moon to perform a series of microwave sintering experiments aiming to develop a potential fabrication method of an extraterrestrial construction process. As part of this initiative, we have designed an industrial bespoke microwave heating apparatus. This apparatus will allow a thorough experimental investigation of the sintering mechanism of lunar regolith/simulant in the cavity. The mechanical properties of sintered specimens produced under optimal conditions can then be explored. The experiment will also be validated using COMSOL Multiphysics simulation software. In this contribution, we discuss the first outcomes using the bespoke microwave heating apparatus, and how COMSOL has been employed to understand the different characteristics of lunar regolith when subjected to microwave heating.

Building 3D objects directly from CAD data using purpose built machines is a technique known as Rapid Manufacturing and these processes allow great freedom in the design of the geometry of the manufactured component. These machines build components by selectively depositing or initiating the phase change of a material, bonding sequential layers together. Traditional processes are either subtractive or formative in nature, whereas these methods are additive. Niche markets for these processes are continually developing and they challenge conventional methods of design and procurement. The work presented in this paper reports on recent developments in scaling up these process to create complex construction scale components. The work here discussed the development of the approach and preliminary components have been manufactured with different nozzle diameters. The results to date are promising although increasing the deposition precision will improve the quality of the built parts.

This paper summarises a study of the narional design policy, the current status of the design industry and related support programmes offered by the government in South Korea. Government support programmes for Small and Medium Sized Enterprises (SMEs) are analysed based on a questionnaire survey. Seven key recommendations for support programmes and the national design policy are identified as follows: (1) Improving PR in relation to the national design policy and related design support programmes, (2) Developing different support programmes for Medium sized (ME)s and Small Enterprises (SE)s, (3) Developing the support programmes more practically, (4) Improving the quality of design consultancies and subdividing them into specific fields of design consultancies, (5) Providing practical education and training programmes for designers and Chief Executive Officers(CEOs), (6)Re-considering the main operator in support programmes and (7) Raising the value of the 'Good Design' award and its globalisation.

A novel Concrete Printing process has been developed, inspired and informed by advances in 3D printing, which has the potential to produce highly customised building components. Whilst still in their infancy, these technologies could create a new era of architecture that is better adapted to the environment and integrated with engineering function. This paper describes the development of a viable concrete printing process with a practical example in designing and manufacturing a concrete component (called Wonder Bench) that includes service voids and reinforcement. The challenges met and those still to be overcome particularly in the evaluation of the manufacturing tolerances of prints are also discussed.

For an extended stay on the Moon, humans will require habitation with substantial shielding for protection from radiation and micrometeorites. Lunar regolith (soil) is a readily available in-situ resource, which can be thermally treated to extract oxygen and water, as well as for construction. For example, lunar habitats and infrastructure can be built by robots using additive manufacturing techniques. Due to the volumetric heating characteristic, intrinsic to microwave heating, it is a more energy-efficient process than solar or laser sintering for large-scale manufacturing and construction purposes. Proof of concept experiments have demonstrated that microwaves couple efficiently with lunar regolith simulants; therefore, microwaves could be an efficient mechanism to sinter and melt lunar regolith to build 3D structures and also enable the extraction of volatiles. These experiments are based on simulated conditions and materials; thus, there is missing information on microwave heating of lunar regolith, which includes the effects of nanophase iron (np-Fe0) produced via space weathering, the highly electrostatic nature of the particles, and irregular particle geometries of the real lunar soil. Through a UK Space Agency (UKSA) grant (NSTP GEI) we are developing a conceptual design of the Microwave Heating Demonstrator (MHD) payload that could be delivered to the lunar surface for in-situ experiments via the ESA?s HERACLES mission or NASA?s CLPS programme. Here, we provide further details of our conceptual design of a MHD payload.

We propose a novel intelligent approach into 2D to 3D of on-line sketching in conceptual design. A Multilayer Perceptron neural network is employed to construct 3D freeform surfaces from 2D freehand curves. Planar curves were used to represent the boundary strokes of a freeform surface patch and varied iteratively to produce a training set. Sampled curves were used to train and test the network. The results obtained demonstrate that the network successfully leaned the inverse-projection map and correctly inferred respective surfaces from curves previously unencountered.

This paper presents a novel free-form surface recognition method from 2D freehand sketching. The approach is based on the Radial basis function (RBF), an artificial intelligence technique. A simple three-layered network has been designed and constructed. After training and testing with two types of surfaces (four sided boundary surfaces and four close section surfaces), it has been shown that the method is useful in freeform surface recognition. The testing results are very satisfactory.

In this paper, we would revisit the usability of microwave for lunar regolith sintering through an in-depth experiment, and examine the minimum materials and energy required for sintering based on the SinterHab design. This will include the minimum layers to print, estimated printing time, minimum energy required for the sintering process and the potential energy sources.

A novel intelligent approach into 3D freeform surface reconstruction from planar sketches is proposed. A multilayer perceptron (MLP) neural network is employed to induce 3D freeform surfaces from planar freehand curves. Planar curves were used to represent the boundaries of a freeform surface patch. The curves were varied iteratively and sampled to produce training data to train and test the neural network. The obtained results demonstrate that the network successfully learned the inverse-projection map and correctly inferred the respective surfaces from fresh curves.

The GEoMetric CONfiguration (GEMCON) project, conducted in the CAD Centre, University of Strathclyde, investigated means of providing appropriate computational support for early design through ? development of a uniform scheme for representing vaguely defined geometric concepts or geometric configurations at multiple levels of detail, suitable for re-use in downstream computer-based design processes, and of a constraint-based reasoning approach to supporting development of geometric configuration solutions [Guan et al, 1997]; ? development of a sketcher-based user interface as a platform for investigating appropriate interaction mechanisms for rapid input of vague or concrete geometric information for establishing geometric configuration models, and for editing and presenting such models in ways suited to functional evaluation from multiple viewpoints [Stevenson et al, 1996]. The focus of this paper is the development of the sketcher-based user interface.

Using Automated Additive Construction (AAC), low-fidelity large-scale compressive structures can be produced out of a wide variety of materials found in the environment. Compressionintensive structures need not utilize materials that have tight specifications for internal force management, meaning that the production of the building materials do not require costly methods for their preparation. Where a certain degree of surface roughness can be tolerated, lower-fidelity numerical control of deposited materials can provide a low-cost means for automating building processes, which can be utilized in remote or extreme environments on Earth or in Space. For space missions where every kilogram of mass must be lifted out of Earth?s gravity well, the promise of using in-situ materials for the construction of outposts, facilities, and installations could prove to be enabling if significant reduction of payload mass can be achieved. In a 2015 workshop sponsored by the Keck nstitute for Space Studies, on the topic of Three Dimensional (3D) Additive Construction For Space Using In-situ Resources, was conducted with additive construction experts from around the globe in attendance. The workshop explored disparate efforts, methods, and technologies and established a proposed framework for the field of Additive Construction Using In-situ Resources. This paper defines the field of Automated Additive Construction Using In-situ Resources, describes the state-of-the-art for various methods, establishes a vision for future efforts, identifies gaps in current technologies, explores investment opportunities, and proposes potential technology demonstration missions for terrestrial, International Space Station (ISS), lunar, deep space zero-gravity, and Mars environments.

The future of sustained human space exploration is likely to rely on the use of local resources on the respective planetary bodies. The continuing exploration of the Moon via orbiter, lander and sample return makes it the next logical destination for setting up human outposts, laboratories, and observatories. Its proximity to Earth also makes it an ideal first destination before we explore further out in the Solar System. Lunar soil is a potential construction resource which can be melted or sintered for building structures [1]. To process the lunar soil, some form of compact, lightweight, electrically powered heat source is required and for this work microwave energy has been selected as it fulfils these criteria well. This research focusses on understanding the interaction of microwave energy with lunar soil. The heat-treated soil can then be fed into a 3D printing apparatus, enabling robotic missions to build structures on the Moon [2]. Lunar soil simulants JSC-1A (lunar mare soil simulant) and NU-LHT-3M (lunar highlands soil simulant) have been used for the experiments in this research. Lunar soil [3] is abundant in silicate minerals and glasses with traces of some other minerals. JSC1A [4] and NU-LHT-3M [5] also has silicates, glass and other minerals. Previous research has shown that lunar soils and lunar soil simulants (LSS) melt during sustained exposure to microwave radiation at a frequency of 2.45 GHz [1, 6]. The melting of lunar soil under microwave heating is commonly attributed to the presence of nano phase Fe0(np-Fe0) [1, 7-9]. However, JSC-1A being a terrestrially manufactured lunar soil simulant, does not contain np-Fe0; however, it melts under microwave heating [6].

The Open University has a heritage in developing small mass spectrometers for planetary lander payloads. The first was a 6 cm radius magnetic sector instrument for light element isotopic analysis (H, C, N, and O), part of the Gas Analysis Package (GAP) on the Beagle 2 Mars lander. The second was the Ptolemy ion trap mass spectrometer (ITMS) on the Philae lander which successfully operated and returned results during the comet landing in November 2014. The Ptolemy ion trap unit fits within a 10 x 10 x 10 cm cube, including RF, detector and ion source electronics and is capable of a mass range from 10 to 150 amu at unit resolution. Development is continuing for purposes ranging from lander instruments (ProSPA and LUVMI), to rugged deployable probes (penetrators) and for process monitoring within ISRU plant. Many of the planned developments are aimed at the various stages of lunar ISRU, from resource prospecting to demonstration and optimisation of extraction processes.

Shape grammars have been used to explore design spaces through design generation according to sets of shape rules with a recursive process. Although design space exploration is a persistent issue in computational design research, there have been few studies regarding the provision of more preferable and refined outcomes to designers. This paper presents an approach for the categorisation of design outcomes from shape grammar systems to support individual preferences via two customised viewpoints: (i) absolute preference values of shape rules and (ii) relative preference values of shape rules with shape rule classification levels with illustrative examples.

Identifying the best technique for extracting water ice deposits in permanently shadowed regions at the lunar poles will be crucial in determining how successful a long-term or permanent settlement at these locations will be for future scientific and technology missions. This study uses a low-power microwave heating method to extract water from icy lunar simulants. Samples of lunar highland and mare simulants at different water contents (3–15 wt %) were heated using 250 W, 2.45 GHz microwaves. A maximum of 67 ± 5% [2SD] of the water was extracted during heating runs of 25 min. Water was extracted more efficiently from the highland simulant than from the mare simulant. A significant reason for the different efficiency of water extraction in icy lunar simulants was the differing porosity of the samples made from different simulants. Pore space filled with ice leads to a reduced contact area between grains and an increased area of free ice, which causes poor heating performance. The results indicated that differences in chemical composition between the simulants had a negligible effect on water extraction, as the contact area between grains seems to dominate water extraction. This study found that low-power microwave heating is an effective technique for extracting water from cryogenic Icy simulants. It was also found that using a simple input energy principle (Input Energy = Absorbed Power x Heating Time) to estimate the additional heating time was sufficient to overcome inefficient heating due to differing absorbed powers. For undersaturated samples, microwave heating was an efficient heating mechanism, but is less efficient for saturated samples where alternative heating methods may be more efficient at melting free ice before employing microwave heating. •Microwave heating can be used to extract water from cryogenic icy lunar simulants.•Compositional differences in simulants have negligible effects on water extraction.•Water-saturated samples show low extraction compared to low-water-content samples.•The low extraction is due to low grain contact area and increased ice surface area.•The saturated sample's low water extraction can be mitigated by additional heating.

Water ice deposits existing in Lunar polar regions of permanent shadow at temperatures as low as 30 K could be a crucial resource required to sustain a human presence on the lunar surface. Recent work has shown microwaves efficiently heat lunar simulants, with promising results for the extraction of water from icy simulants. Through funding from The Open University?s Space SRA initiative, and ESA?s Off-Earth Manufacturing and Construction Campaign, we have heated lunar simulants doped with water cooled down to initial temperatures of < 120 K in a microwave heating unit (MHU). The MHU supplies microwaves, adjustable in power from 0 to 1 kW, to samples in a cavity capable of operating at pressures from 1 atm down to 10-5 mbar.

This study describes the development of an instrument known as the dynamic mass instrument (DMI) for use in microwave heating experiments that will allow greater insight in to the efficacy of the technique. A commercially available load cell is used as the main mechanism of mass measurement with a load arm used to provide microwave isolation of the load cell. The DMI is capable of measuring changes in mass with a mass range of 100 g to 200 g with an accuracy of ± 0.1 g in an environment of 250 W, 2.45 GHz microwaves under a working pressure of 3 mbar. A series of calibrations and experiments have been performed to quantify and clarify the behaviour of the instrument in different environments and scenarios and to ensure the DMI meets preset requirements. The DMI will, in future work, be used in In Situ Resource Utilisation experiments to examine in greater detail the efficacy of using microwave heating as a water extraction technique.

Water ice present at the lunar poles represents a potentially crucial resource for allowing a sustainable cislunar economy [1]. Microwave heating offers an efficient technique to extract the water ice directly from the regolith [2]. Volumetric heating throughout a sample means that the low thermal conductivity of lunar regolith can be overcome allowing efficient heat transfer and large-scale water extraction.In this work, icy regolith samples have been created with two different forms of ice: permafrost and granular.  Both types of samples were made to a water content of 5 wt. % and used LHS-1 as the simulant choice. Two grain size distributions for granular ice were used with average grain sizes of 1.3 and 2.7 mm. A bespoke microwave heating unit was used to heat the samples using 250 W microwaves for 60 minutes. A dynamic mass instrument was used that was able to measure the real time mass of samples in situ. This allowed the mass loss over time to be measured.The average extraction profiles for all sample types can be seen in Figure 1. It has been found that high extraction was possible for all samples in 60 minutes (>80 %). All the profiles are similar in that a minimum amount of heating time was required before water was extracted. Both the permafrost and small granular ice samples had similar extraction profiles, while the large granular ice samples show a distinctly different profile as the ice is released in discrete sections. I will present these results and demonstrate the feasibility of using microwave heating as a water extraction technique.

The use of space resources will play a vital role in sustaining a permanent human presence on the lunar surface. In Situ Resource Utilisation (ISRU) allows the extension of current and future missions. A vitally required resource at the lunar surface is rocket propellant allowing the movement of humans back to cislunar space and more complex missions into deep space. Water ice stored at the lunar poles in Permanently Shadowed Regions (PSRs) could be used as rocket propellant. The water ice in PSRs is stored at < 110 K and measured in situ at 5.6 ± 2.9 wt. %. The ice is present in such quantities that it could allow a valuable cislunar economy to be established. The exact nature of water ice stored at PSRs is currently unknown; however, finding a technique that maximises the water ice extraction as quickly as possible will be crucial given the harsh conditions present in a PSR (no solar energy, < 110 K, vacuum conditions). Microwave heating could offer quick water ice extraction without regolith excavation. Microwave heating offers deep volumetric heating meaning substantially higher heating rates than other possible techniques. High-power microwave heating has already been proven as a useful ISRU technique in additive. This work concentrates on using low-power (250 W) microwave heating to extract water ice from icy lunar simulants.

Introduction: The concept of the Microwave Heating Demonstrator (MHD) payload was developed as part of the collaborative project MARVEL (Microwave heating Apparatus for Regolith Variant Experiments for Lunar ISRU) between the Open University, Added Value Solutions UK Ltd. and VIPER RF in 2019 [1] to explore the potential of microwave heating method for lunar construction and resource extraction, and serve as a viable option for selection on future NASA/ESA missions to the Moon [2]. As part of the MHD cavity design development, we conducted intensive analyses of the microwave heating performance via lab experiments and computational simulations. Through these experiments, we improved our understanding of the microwave heating behaviour of lunar soil/simulants [3,4] and discovered a few challenges [1] that have been addressed via an updated MHD payload design. In this presentation, we will discuss the up-to-date design of the MHD payload (Fig. 1) and a new set of experiments using a prototype of the barebone system. As a result of the recent updates, the payload length is slightly increased from 400 to 450 mm (450 x 400 x 250 mm), but a reduction in the overall mass (12 kg to 11 kg). In addition, the peak power requirement is also reduced from 677 W to 450 W, with the expected DC-to-RF efficiency >60%.

Water ice deposits at the lunar poles could be a crucial source of water required to sustain human presence on the lunar surface. Microwave heating could be used to extract this water. Recent work has shown that microwaves efficiently heat lunar simulants, and numerical simulations have shown that this is equally applicable for the actual lunar regolith. Icy simulants can be heated efficiently where extraction of large amounts of water has been shown, but work to date has been limited in the sample temperatures possible. In this work, lunar simulants doped with various water contents were chilled to temperatures of 115 K and heated in a microwave heating unit (MHU). The MHU supplies microwaves, adjustable in power from 0 to 1 kW, to samples in a cavity capable of operating at pressures down to 10-5 mbar. The mass loss of water was recorded and compared to the original water content to calculate the extraction efficiency (EE) of the process, which was found to be higher for samples with higher water contents.

MARVEL (Microwave heating Ap- paratus for Regolith Variant Experiments for Lunar ISRU) is a collaborative project between the Open Uni- versity (OU), Added Value Solutions UK Ltd. and VI- PER RF. The team has been developing a concept Mi- crowave Heating Demonstrator (MHD) payload since 2019 with the ambition to understand the proper- ties of microwave heated lunar regolith under controlled conditions, explore their potential for lunar construction and resource extraction, and serve as a viable option for selection on future NASA/ESA missions to the Moon. As part of the payload development, the OU team has conducted extensive analysis on the microwave heating behaviour of lunar regolith simulants. Previous experiments were conducted under atmos- pheric conditions, resulting in significant findings and new insights into the potential use of microwave energy for lunar construction and resource extraction; and providing a rationale for the MHD payload devel- opment. This presentation discusses the preliminary re- sults of further experiments performed under vacuum conditions with lunar simulants representing the lunar mare (JSC-1A) (Figures 1 and 2) and far-side highland material (OPRH3N). 

MARVEL (Microwave heating Apparatus for Regolith Variant Experiments for Lunar ISRU) is a collaborative project between the Open University, Added Value Solutions UK Ltd. and VIPER RF. The team has been developing the Microwave Heating Demonstrator (MHD) payload since 2019 with the ambition to perform pre-defined experiments on the Moon, which explore the potential of microwave heating-based 3D printing for developing a lunar construction process and in-situ resource extraction, available for selection on future NASA/ESA missions to the Moon. The final goal of the MARVEL project is to support ESA’s Terrae Novae 2030+ strategy roadmap for the Moon, particularly for the large surface habitat and ISRU pilot plant & excavation missions. The initial concept development of the MHD payload was completed with support from UKSA’s NSTP GEI (GEI2-037), Pathfinder (PF3-090), Space Exploration Technology (UKSAG21_0088), and ESA’s Off-Earth Manufacturing and Construction Campaign (4000133998/21/NL/GLC) (Figure 1).In this presentation, we will report the current progress of the MHD development conducted through the ESA’s Off-Earth Manufacturing and Construction Campaign as part of the Open Space Innovation Platform (OSIP), focusing on the challenges with optimising the heating performance of the MHD cavity design.

Oxygen has been extracted from molten lunar simulants using laser energy (simulating solar radiation). Microwave energy has been proposed as a heat source to sinter or melt lunar regolith for use in additive manufacturing because microwaves couple efficiently with lunar regolith. Here we describe preliminary experiments to extract oxygen using hydrogen reduction and carbothermal reactions from the molten lunar regolith using microwave energy.

Lunar regolith contains various chemical and mineralogical resources, which can be extracted to build an outer habitat shell using additive manufacturing techniques (a.k.a. 3D printing) by robots. Proof of concept experiments have demonstrated that microwave radiation couples efficiently with lunar regolith resulting in sintering/melting, which could enable resource extraction and the fabrication of 3D structures. However, there still remain major unkowns relating to lunar soil interactions with microwaves that can only be answered through experiments on the Moon surface; for example the effects of nanophase iron (np-Fe0), the highly electrostatic nature of the particles, and irregular particle geometries of the real lunar soil. At the Open University (OU), we have embarked on a collaborative project called MARVEL (Microwave heating Apparatus for Regolith Variant Experiments for Lunar ISRU), with Added Value Solutions UK Ltd. and VIPER RF. The team aims to develop a Microwave Heating Demonstrator (MHD) payload which can be deployed on the lunar surface. The ambition is that the MHD will perform pre-defined experiments and be available for selection on future NASA/ESA missions to the Moon. The initial concept of the MHD payload was developed with support from UK Space Agency (UKSA)’s Grants for Exploratory Ideas (GEI) funding under the National Space Technology Programme.

Introduction: The emerging era of lunar exploration aims to develop a more sustainable approach, which would require careful planning, preparation, and execution of surface operations, utilising the available resources on-site efficiently while minimis-ing the impact on the local lunar environment [1]. To realise this vision, significant technological developments are taking place for lunar in situ resource utili-sation (ISRU) [2], mainly utilising terrestrial analogues. However, the aspects of lunar ISRU research could be of immediate relevance to terrestrial applications , such as in the mining sector, which faces many similar challenges. Thus, a synergistic approach involving lunar ISRU research with potential terrestrial applications could make critical contributions to areas such as raw materials and circular economy. Context: Several missions are in progress or being planned to enable the surface exploration of the Moon through human-robotic partnerships. These lunar surface operations are likely to involve extended stays for astronauts, including at locations that have never been visited by humans before (e.g., polar regions of the Moon or the far side). Regardless of the landing location, the most readily available resource at the Moon is the regolith, which could provide a feedstock for the extraction of critical elements such as hydrogen, oxygen, and other metals, besides being beneficial for construction processes such as 3D printed habitats, tools, and other structures [3,4]. Techniques are being developed to handle, process, and utilise the entirety of lunar regolith so that it produces zero waste. A comparable need exists on Earth in the mining sector where traditionally, a large amount of 'waste' is produced in extracting the target element(s), leaving a large 'footprint' that is often environmentally damaging and sometimes poses a danger to local communities. Thus, there is a tremendous potential for applying some of the techniques developed for lunar ISRU to the remediation of historic mine 'waste', and integration into current and future mining operations to improve the efficiency of mining itself while enabling cross-fertilisation of ideas between practitioners in the space sector and terrestrial mining and manufacturing industries. A new approach: Inspired by our lunar ISRU work, we have recently embarked on a project which involved a survey of legacy mine sites in north Wales, UK, which has witnessed centuries of mining activity for metals such as Cu and Zn, along with roofing material such as slates. We conducted fieldwork to collect samples of mine 'waste' from four historical mine

When a volcano erupts, it is often associated with destruction, particularly damage to infrastructure and loss of life. But these natural events also offer unexpected research opportunities, leading to serendipitous discoveries. this was the case for the volcanic events that made the headlines during 19 September to 25 December 2021, on the Canarian Island of La Palma. rather than viewing the voluminous ash that erupted as a waste material needing to be removed as soon as possible, we saw the many possibilities that this remarkable material could offer science and engineering. Sustainability is a word that is commonly used in connection with geology these days. Here we present some possibilities of how the La Palma ash can be re-purposed for use on this planet but also help us to develop new ideas for the future living on the Moon.

The process of sketching can support the sort of transformational thinking that is seen as essential for the interpretation and reinterpretation of ideas in innovative design. Such transformational thinking, however, is not yet well supported by computer-aided design systems. In this paper, outcomes of experimental investigations into the mechanics of sketching are described, in particular those employed by practicing architects and industrial designers as they responded to a series of conceptual design tasks. Analyses of the experimental data suggest that the interactions of designers with their sketches can be formalised according to a finite number of generalised shape rules. A set of shape rules, formalising the reinterpretation and transformations of shapes, e.g. through deformation or restructuring, is presented. These rules are suggestive of the manipulations that need to be afforded in computational tools intended to support designers in design exploration. Accordingly, the results of the experimental investigations informed the development of a prototype shape synthesis system, and a discussion is presented in which the future requirements of such systems are explored.

Many governments around the world acknowledge the role and value of design and have formulated design policies including national business support programmes in design, and have invested in building the capacity of their design sectors. This paper reports on an investigation of national design policies in the UK and South Korea, and recommends alternative models for developing and implementing these policies.

As design has increasingly become regarded as a strategic tool that makes a critical contribution to enhancing competitiveness and economic success, a growing number of businesses now consider the use of design as a means of achieving their business goals. Governments, too, have embraced policies that encourage businesses to develop and implement new products and services through the use of design. Yet, despite the efforts of companies to expand their business into overseas markets with government support, achieving their goals in the rapidly changing competitive environment of the global marketplace and economy is becoming increasingly difficult. Researchers have proposed that the purpose of a national design policy is to ensure that the appropriate design support is provided for businesses to become globally competitive. Such research has analyzed the influence of design on global competitiveness; however, few researchers have addressed the influence of national design policy on global competitiveness either longitudinally or in relation to indigenous industry. In this paper we examine in two different countries (i.e., the U.K. and South Korea) the relationship between national design policies and industrial development, as evidenced through a government-supported design center?s strategy, activities, and industrial support. We also compare the two cases to understand national design policy and how it influences indigenous industry. These two countries have been selected because of the difference in the level of maturity in their ?design? support (i.e., United Kingdom has a very mature Design Council, while the Korea Institute of Design Promotion (KIDP), in South Korea, is relatively new); yet similar in their design and innovation index ranking in the Global Competitiveness Report.6 Both countries also have been described as having a clear and effective design policy and have applied government design policy and design promotion programs that have intensified the role of design in international competition. It has also been suggested that the United Kingdom has a strong government-supported design export program; that as the largest design industry in Europe, its annual turnover exceeds 11.6bn; and that it is a key knowledge hub in the global economy. In South Korea the government has invested in infrastructure for design promotion, has increased the quality and quantity of design education, and has extended the use of design in industry, gaining recognition through its ambitious design policy framework and its design program. To understand and compare the two nations? approaches to policy, we undertook a detailed desk research and examined documentary evidence related to the activities of each council. In the U.K., this analysis included using Design Council archives at Brighton University to study every annual report and accounts and strategy document since 1940. In South Korea, records at KDIP were used, along with other literature on its policy. This paper presents the findings for both countries during the period from 1940 to the present. For convenience and clarity, they are described in decades, and we present the activities and policies of each council in the context of the prevailing economic and industry performance for each period. The paper concludes with a short comparison of the councils and their national policies and the conclusions that can be drawn from such a review.

The field of In Situ Resource Utilisation (ISRU) is expanding rapidly with a particular focus on developing ISRU technologies and applications to support a longer-term surface exploration of the Moon. In this respect, microwave sintering is proposed to be one of the potential fabrication methods for developing a 3D printing technique for construction processes on the Moon. Thus, understanding the behaviour of lunar regolith, available at different locations on the Moon (e.g. mare versus highlands regions), under microwave heating is crucial for developing an optimal method for microwave sintering. As the availability of real lunar regolith on Earth is highly limited, developing an appropriate numerical model of microwave heating behaviour of lunar regolith is urgently required. In this paper, three representative lunar regolith samples (selected from the database of Apollo sample collections) with pre-defined material properties have been simulated under seven input powers and three specimen sizes. This paper discusses the outcomes of these simulations and the potential contribution of the model for developing a desired 3D printing technique utilising microwave sintering of lunar regolith.

In this paper, a non-conventional way of additive manufacturing, curved-layered printing, has been applied to large-scale construction process. Despite the number of research works on Curved Layered Fused Deposition Modelling (CLFDM) over the last decade, few practical applications have been reported. An alternative method adopting the CLFDM principle, that generates a curved-layered printing path, was developed using a single scripting environment called Grasshopper – a plugin of Rhinoceros® . The method was evaluated with the 3D Concrete Printing process developed at Loughborough University. The evaluation of the method including the results of simulation and printing revealed three principal benefits compared with existing flat-layered printing paths, which are particularly beneficial to large-scale AM techniques: (i) better surface quality, (ii) shorter printing time and (iii) higher surface strengths.

This paper is concerned with how design shapes are generated and explored by means of sketching. It presents research into the way designers transform shapes front one state to another using sketch representations. An experimental investigation of the sketching processes of designers is presented. Connections between sketches are defined in terms of shape transformations and described according to shape rules. These rules provide a formal description of the shape exploration process and develop understanding of the mechanics of sketching in design. The paper concludes by discussing the important phenomenon of 'subshape' and suggests that a computational mechanism for detecting sub-shapes in design sketches might augment explorative sketching by providing important opportunities for manipulating and generating shape in design. (C) 2009 Elsevier Ltd. All rights reserved.

This paper discusses a comparative study of national business support programmes in design operated by National Design Centres (NDCs) in the UK and South Korea. The research identified the drivers for, and barriers to, implementing national support programmes in design and presents the recommendations for new approaches to the development and implementation of such programmes. The research findings illustrate that while there are some similarities in barriers to implementing such programmes, government support for businesses through NDCs differs in the two countries due to the different content and structure of programme delivery. The research findings also indicate that critical issues influencing national support in design are autonomy and respective organizations' perspectives and purposes.

•Reviewed current efforts on developing an extra-terrestrial construction process.•The review consists of three categories: materials, fabrication and process.•Discussed the major concerns and challenges for the above efforts.•The above efforts would support permanent settlement of other planetary bodies.•A logical pathway is to develop an appropriate AM-based printing system. Government space agencies, including NASA and ESA, are conducting preliminary studies on building alternative space-habitat systems for deep-space exploration. Such studies include development of advanced technologies for planetary surface exploration, including an in-depth understanding of the use of local resources. Currently, NASA plans to land humans on Mars in the 2030s. Similarly, other space agencies from Europe (ESA), Canada (CSA), Russia (Roscosmos), India (ISRO), Japan (JAXA) and China (CNSA) have already initiated or announced their plans for launching a series of lunar missions over the next decade, ranging from orbiters, landers and rovers for extended stays on the lunar surface. As the Space Odyssey is one of humanity’s oldest dreams, there has been a series of research works for establishing temporary or permanent settlement on other planetary bodies, including the Moon and Mars. This paper reviews current projects developing extra-terrestrial construction, broadly categorised as: (i) ISRU-based construction materials; (ii) fabrication methods; and (iii) construction processes. It also discusses four categories of challenges to developing an appropriate construction process: (i) lunar simulants; (ii) material fabrication and curing; (iii) microwave-sintering based fabrication; and (iv) fully autonomous and scaled-up construction processes.

This paper presents the experimental results concerning the mix design and fresh properties of a high-performance fibre-reinforced fine-aggregate concrete for printing concrete. This concrete has been designed to be extruded through a nozzle to build layer-by-layer structural components. The printing process is a novel digitally controlled additive manufacturing method which can build architectural and structural components without formwork, unlike conventional concrete construction methods. The most critical fresh properties are shown to be extrudability and buildability, which have mutual relationships with workability and open time. These properties are significantly influenced by the mix proportions and the presence of superplasticiser, retarder, accelerator and polypropylene fibres. An optimum mix is identified and validated by the full-scale manufacture of a bench component.

The future of human space exploration will inevitably involve longer-term stays and possibly permanent settlement on the surfaces of other planetary bodies. It will, therefore, be advantageous or perhaps even necessary to utilise local resources for building an infrastructure for human habitation on the destination planetary body. In this context human lunar exploration is the next obvious step. Lunar soil is regarded as an ideal feedstock for lunar construction materials. However, significant gaps remain in our knowledge and understanding of certain chemical and physical properties of lunar soil, which need to be better understood in order to develop appropriate construction techniques and materials for lunar applications. This article reviews our current understanding of the dielectric behaviour of lunar soil in the microwave spectrum, which is increasingly recognised as an important topic of research in the Space Architecture field. Although the coupling between the lunar soil and microwave energy is already recognised, considerable challenges must be overcome before microwave processing could be used as a main fabrication method for producing robust structures on the Moon. We also review the existing literature on the microwave processing of lunar soil and identify three key research areas where future efforts are needed to make significant advances in understanding the potential of microwave processing of lunar soil for construction purposes. (C) 2016 Published by Elsevier Ltd.

In this paper a mixed desktop system utilizing computer aided design (CAD) and rapid prototyping (RP) technologies to support form design at the early stages of the design process is described. This new system is an image-mapping-based application in which a simple initial CAD model is modelled in a commercial package (Alias StudioTools) and then automatically updated by a software which uses pictures of its sculpted rapid prototyping model (RPM) representation. The automatic updating process is carried out by comparing the images of the primary CAD model and the picture of the sculpted RPM. The latter is taken by a simple digital camera or web-cam using the same coordinate transformations as the CAD model. The use of white and black stripes in the RPM and skinning sections in the CAD model allows the detection of differences between the two representations and hence, the updating of the primary CAD model. The new CAD model is then transferred back into StudioTools for further developments. This new approach is quicker and simpler to use than alternative technologies, such as three-dimensional scanning.

For a sustainable human presence on the Moon, it is critical to develop technologies that could utilise the locally available resources (a.k.a. in situ resource utilisation or ISRU) for habitat construction. As the surface soil is one of the most widely available resources at the Moon, we have investigated the viability of microwave heating of a lunar soil simulant (JSC-1A). JSC-1A was thermally treated in a bespoke microwave apparatus using 2.45 GHz frequency, using five different microwave powers in the range of 250 W to 1000 W. The structural properties of the resulting products were analysed to determine whether their microstructures and mechanical strengths differ under different input powers; and whether input power plays a crucial role in triggering thermal runaway, for identifying the optimum power for developing a microwave-heating. Our key findings are: (i) the higher input powers (800 W and 1000 W) generate the highest yields and microstructures with the greatest mechanical strengths, at the shortest fabrication times, and (ii) thermal runaway improves the microwave heating efficiency despite the rapid increase in temperature, once it is triggered. Our findings are of key importance for developing a microwave-heating payload for future lunar ISRU demonstration missions, contributing towards 3D printing-based extra-terrestrial construction processes.

This paper presents the hardened properties of a high-performance fibre-reinforced fine-aggregate concrete extruded through a 9 mm diameter nozzle to build layer-by-layer structural components in a printing process. The printing process is a digitally controlled additive method capable of manufacturing architectural and structural components without formwork, unlike conventional concrete construction methods. The effects of the layering process on density, compressive strength, flexural strength, tensile bond strength and drying shrinkage are presented together with the implication for mix proportions. A control concrete (mould-cast specimens) had a density of approximately 2250 kg/m(3), high strength (107 MPa in compression, 11 MPa in flexure) and 3 MPa in direct tension, together with a relatively low drying shrinkage of 175 pm (cured in water) and 855 mu m (cured in a chamber at 20 degrees C and 60% relative humidity) at 184 days. In contrast well printed concrete had a density of 2350 kg/m(3), compressive strength of 75-102 MPa, flexural strength of 6-17 MPa depending on testing direction, and tensile bond strength between layers varying from 2.3 to 0.7 MPa, reducing as the printing time gap between layers increased. The well printed concrete had significantly fewer voids greater than 0.2 mm diameter (1.0%) when compared with the mould-cast control (3.8%), whilst samples of poorly printed material had more voids (4.8%) mainly formed in the interstices between filaments. The additive extrusion process was thus shown to retain the intrinsic high performance of the material. (C) 2011 Elsevier Ltd. All rights reserved.

The purpose of this study was to deploy a Delphi expert elicitation methodology to better understand the technical and policy challenges facing the development of a sustainable lunar outpost in 2040, including the types and scale of In-Situ Resource Utilisation (ISRU) deployment. We used a three-round Delphi survey with an open first round and specific questions in later rounds using a four-point Likert scale and two ranking exercises to assess energy technologies and inhibiting factors. In order to provide more certainty to our potential participants regarding their input, and boost engagement, the study deployed a three-round approach that was communicated to our potential participants and decided ex-ante. Potential participants were identified from the literature and academic networks as those who had made significant contributions to the fields of: ISRU technologies, space architecture, space-qualified power systems, and space exploration. The study identified around 20 major themes of interest for researchers in the first round and asked participants to rate their agreement with a number of statements about a hypothetical lunar outpost in 2040. From the group responses, we identified three major technical challenges for the development of a lunar outpost in 2040; developing high power energy infrastructure, lander and vehicle ascent capacity, and mission architectures and technical approaches. We also identified three major policy challenges for the development of a lunar outpost in 2040: (i) US and global political instability, (ii) possibility of an extended timeframe for the first lunar landing, and (iii) political distaste for nuclear energy in space. The group was uncertain about the precise energy mix at the outpost as a result of uncertainty regarding electrical loads, but there was general agreement that solar PV would be a significant contributor. Whether nuclear power sources might play a useful role proved to be very uncertain, with some participants noting a political distaste for space nuclear power systems. However, the proposition gained two votes in each ranking position, suggesting it has a flat distribution including both supporters and detractors. •US and global instability, power for ISRU and lunar lander capacity are critical barriers to a lunar outpost.•ISRU processes could add 1 MW of power requirements to lunar outpost.•ISRU researchers lack confidence NASA lunar exploration timelines.•Group could not reach consensus on Covid-19's impact on space exploration.

•Chemically processed ISRU structures incur significant upmass penalties.•Energy requirements of thermally processed ISRU structures are large.•Nuclear power plant with thermal processing is efficient for large structures.•Chemically processed ISRU structures have lower overall upmass when small.•Thermal processing options open up concurrent volatile extraction possibilities. The purpose of this study was to establish, on a first principles basis, the order of magnitude of energy requirements for a thermally processed, lunar regolith radiation shield constructed using an in-situ resource utilisation (ISRU) approach. This was done by developing a reference scenario habitat and using thermodynamic relationships and specific heat capacity expressions to determine the energy required to bring such a regolith volume up to sintering temperatures (c. 1,375 K). Once the energy requirements were developed some power system architectures were outlined conceptually and a nuclear power plant of c. 400 kW was suggested as a means to supply the necessary energy. This is well beyond current space nuclear applications. The study concludes that it is likely that the most efficient near-term solution is chemical processing of regolith, from an energy requirements perspective. The technology is also more mature and likely to be delivered on near term projects as it does not require such scaled-up power system architectures. Alternatively, bringing storm shelters up with the habitat to provide a means of weathering major solar events, and adding additional radiation protection to habitat quarters, possibly through a water blanket or similar mechanism, could provide a non-ISRU solution with current technology. However, in the longer term, the development of MW-scale power system architectures (fission, solar etc.), may permit a very large volume of material to be processed thermally for construction material, making a large, permanent human presence on the Moon more easily realisable.

The formal approach outlined in this paper uses symbolic memes as a framework for the hierarchical deconstruction of a cultural artefact, the traditional Korean pattern known as bosangwhamun, to describe the evolutionary development of such a pattern using shape grammar rules. The formal descriptions of this pattern are thus the basis for generating its variations, and the process is used to evaluate the validity of the rules and their appropriateness for the study of bosangwhamun.

Additive manufacturing in construction is beginning to move from an architect's modelling tool to delivering full-scale architectural components and elements of buildings such as walls and facades. This paper discusses large-scale additive manufacturing processes that have been applied in the construction and architecture arena and focuses on 'Concrete Printing', an automated extrusion based process. The wet properties of the material are critical to the success of manufacture and a number of new criteria have been developed to classify these process specific parameters. These criteria are introduced and key challenges that face construction scale additive manufacturing are presented. (C) 2011 Elsevier B.V. All rights reserved.

To achieve a sustainable human presence on the Moon, it is critical to develop technologies utilising the local resources (a.k.a. in-situ resource utilisation or ISRU) for construction and resource extraction. In this study, we investigate the viability of microwave heating of two lunar soil simulants (JSC-1A and OPRH3N) under vacuum conditions, to simulate a lunar surface environment compared to previous studies performed at atmospheric pressure. All simulants are thermally treated in a bespoke 2.45 GHz microwave apparatus using three input powers: 1000 W, 600 W and 250 W. The microstructures and mechanical properties of the microwaved samples are analysed to identify their potential applications. Our key findings are: (i) higher input powers generate materials in shorter fabrication times with higher mechanical strengths and higher yields despite the same total energy input; (ii) the microstructures of the microwaved samples under vacuum are very different from those under atmospheric conditions due to the widespread vesicles/bubbles; and (iii) different heating rates caused by different input powers can be utilised for specific ISRU purposes: higher input powers for extra-terrestrial construction and lower input powers for resource extraction. Findings from this study have significant implications for developing a microwave-heating payload for lunar ISRU demonstration missions.

•Lunar regolith’s electric field in microwaves decreases with the sample temperature over 800 K.•The resonance frequency of the cavity is shifted when the sample is heated.•A single hotspot with high electric field intensity is needed to sinter/melt lunar regolith. Sustainable exploration of the Moon could benefit from a microwave heating-based 3D Printing technology for In-Situ Resource Utilisation (ISRU) purposes such as for the fabrication of habitats and extraction of resources on the Moon. In this context, we have developed a Microwave Heating Demonstrator (MHD) payload concept, which can perform pre-defined ISRU experiments on the lunar surface. The MHD payload would also produce scientifically valuable data in its own right, which would help to establish fundamental criteria for developing a microwave heating-based 3D Printing technique, ultimately enabling lunar construction and other ISRU-derived mission activities. One of the major design criteria of the MHD payload was to enable sustainable heating performance at low microwave power, e.g., 250 W. This paper discusses some non-negligible phenomena during the microwave heating of lunar regolith, which need to be considered for future mission applications. We also present a design of the MHD payload development, focusing on the heating performance of the microwave cavity.

During conceptual design, a designer may wish to describe a shape vaguely, either because it is desired that the shape remains flexible or the shape has not yet been defined precisely. Maintaining the vagueness of an early idea until it is sufficiently developed is often of vital importance. However, most existing systems, mainly due to limitations in their modelling capabilities, attempt to interpret and thereby remove the vagueness at the earliest opportunity. This may lead to the loss of considerable information in original concepts or design fixation too early in the design stage. A new approach is needed to represent and maintain vague geometric information and such an approach is presented in this paper. (C) 2001 Elsevier Science Ltd. All rights reserved.

Today's computer-aided design (CAD) systems are based on underlying technologies developed over 20 years ago. Although they have become a key part of the design process and are ubiquitous in industrial product development processes, they usually come into play after the shape of the design has been created. In essence, today's CAD systems are used to support design evaluation and analysis and downstream applications such as manufacturing. Our research challenge was to bring computers into the start of the creative design process, where they can augment design activity by supporting design synthesis - enhancing and highlighting options that might be open to the designer. Our vision was of a computer aided design synthesis system that can work with and manipulate designers' sketches at the earliest stage of the design process. Previous research in the application of shape grammars to design generation indicated that they offered a potential foundation upon which such a system could be built.

This paper presents our experimental studies on sketching behaviour, processing and individual preference through questionnaire and sketch observation. This study has been carried out to obtain the barebones criteria that will be adopted to develop a free-form surface modelling system from on-line sketching. The results show that some dynamic sketching information, including certain visual forms such as form lines, reference lines, grid lines, shades, shadows, and/or annotations, etc., should be included in a sketch-based modelling system.