Space Operations Research Articles

Development and evaluation of an immersive VR-CFD-Based tool for dust exposure mitigation in underground tunnelling operations

Long-term exposure to respirable coal and silica dust during underground tunnelling operations has gained increasing attention in recent years. The solution to effective mitigation of dust exposure depends not only on higher-order engineering controls, but also on administrative controls for frontline workers. However, there is a disconnect between knowledge gathered in the field of dust exposure monitoring and the frontline worker, resulting in important learnings being overlooked in underground tunnelling operations. To remedy this discrepancy, an immersive educational tool was developed to visualise computational fluid dynamics (CFD) modelling datasets of ventilation and respirable dust flow characteristics in the tunnel face in a virtual reality (VR) environment. An algorithm was developed for processing the large and complex CFD datasets into a form that can be processed and visualised using standalone VR headsets with limited processing power. The VR-CFD system was assessed by an industry expert and via many industry showcases, where regular feedback was received for making significant improvements in this education tool. This tool has been developed as a training platform to allow frontline workers to better understand the results of decisions made during tunnelling operations and the best practices for dust controls. A number of key technological achievements were made that can be used in the future to quickly translate real-world particulate readings collected from underground space into a VR visualiser. This VR-CFD digital technology can readily be extended to mining, construction and other tunnelling operations in the underground space, thus improving health and safety.

Surrogate model-based calibration of a flying Earth observation satellite

At the European Space Agency (ESA), Modeling and Simulation (M&S) plays a fundamental role during the lifetime of a spacecraft, being used from the design phase to the testing and during operations in space. M&S tools embed general physics-based models and disciplines characterized by configurable parameters which have to be calibrated in order to mimic the behavior of the actual flying spacecraft. However, their calibration requires a large number of simulations which are unfeasible to be obtained through computationally expensive high-fidelity simulation models. Thus, the inability to calibrate the high-fidelity simulation models poses limitations for the use of M&S tools during spacecraft operations.In this light, the present work proposes the use of a surrogate model-based approach for the calibration of simulation models of spacecraft. The approach integrates a computationally inexpensive deep-learning-based surrogate model, which mimics the high-fidelity simulation model without requiring the same computational burden, and a metaheuristic optimization algorithm, to identify the optimal values of the simulation model configurable parameters. This enhances the capabilities of M&S tools and allows their use in operations. The approach’s effectiveness is shown by its application to real flying Earth observation satellite data and simulation models.

Thermal-dynamic coupling analysis of space truss antennas in actual space thermal environment

Space truss antennas may undergo thermally induced vibration due to temperature changes caused by thermal mutations in the space environment, which will result in antenna performance degradation or even vibration failure. This paper aims to investigate the thermal-structural coupled dynamics of a space truss antenna in the orbital space thermal environment. A spatial thermal analysis model is established based on the spatial heat flux model, Fourier-temperature element, finite element method (FEM) and astrometric model to calculate temperature variation of the antenna structure during its operation in orbit. In this model, the effective solar heat flux received by the antenna structure is calculated on the basis of an astrometric model, with consideration of the Earth's shadow effect and the shading effect of the reflective surfaces. Additionally, a thermo-structural coupled dynamic model of the antenna structure is constructed considering the coupled effects of structural deformation and absorbed effective solar heat flux, which was validated using a finite element shell model. Numerical cases are arranged to comparatively analyze the thermal-structural coupling effects, light shading by reflective surfaces, and thermodynamic response during the space operation cycle, respectively. It is demonstrated that both the earth shadow effect and the shading effect of components have great effect on the temperature distribution and variation of the antenna structure. Moreover, significant vibrations will occur at certain moments especially when the thermal radiation flux to the structural components changes suddenly due to light shading from the earth shadow and reflective surfaces. The thermal-structural coupling dynamic model of the antenna structure presented in this work can provide guidance for thermal compensation and thermal-induced vibration attenuation of truss antenna structures.

Conjunctive and disjunctive combination rules in random permutation set theory: A layer-2 belief structure perspective

In uncertainty reasoning, conjunctive and disjunctive combination rules are the core tools for information updates. As an extension of evidential reasoning, random permutation set reasoning models uncertain information based on ordered focal sets. Existing combination rules in random permutation set theory, orthogonal sums, do not satisfy the commutativity of one of the original distributions and overly obey its order information. In this paper, the random permutation set theory is interpreted as an refined extension of Dempster–Shafer theory, and a layer-2 belief structure is proposed to describe the permutation event space. Compared with the traditional belief structure, the proposed structure can model both symbolic and numerical uncertainty. Based on the above, the conjunctive and disjunctive combination rules in Dempster–Shafer theory are extended to random permutation set theory. Through properties analysis and simulation demonstration, we demonstrate that the proposed methods can not only resolve the counter-intuitive results of orthogonal sums, but make full use of order information in distributions as well. In addition, we also extend the product space operations and discounting methods based on the proposed methods, and give a general framework of multi-source information fusion under the random permutation set theory.

Interoperable data exchange for safe and efficient launch and re-entry operations in an international environment

The frequency of commercial space launch and re-entry operations is increasing worldwide. Current regulations and procedures ensure safe operations by temporarily closing large volumes of airspace where risks to aircraft would exist in case of non-nominal events during launch or re-entry operations. To maintain the safety of air traffic as the number of space operations rises, effectively providing the right information to the right stakeholders at the right time is key. Through a cooperative agreement, the FAA and DLR are sharing their unique capabilities using the Commercial Space Integration Lab and Air Traffic Validation Center, located in the USA and Germany respectively, to improve situational awareness through real-time data exchange. The project seeks to answer whether U.S. and European ANSPs can respond adequately to a non-nominal event during a launch or re-entry operation that presents a hazard to the airspace system. It leverages existing international data standards and infrastructures by using a data exchange approach based on System Wide Information Management (SWIM). Within the project an initial assessment of the processes, roles and responsibilities for implementing launch and re-entry events in the air traffic systems on both sides of the Atlantic, as well as the requirements for basic functions and performance parameters of a SWIM-based integration, have been completed. The project developed a demonstration model across all system levels as far down as to the ANSPs, namely to the air traffic controllers. Through a series of demonstrations, covering launch scenarios from the U.S. with possible effects on European airspace and vice versa, the project evaluated the technical and operational feasibility of the concept. The key data parameters identified during the analyses shall enable information sharing among various users within the U.S. and European global airspace system. It has been shown, that the systems on both sides of the Atlantic could be connected via standardized protocols und used successfully for exercises in different scenarios. Further research on the best integration of the processes in international Air Traffic Management (ATM) networks and domains will be the follow-on.

Validation results on future flight safety methods to be instituted at the Guiana Space Center -New Generation

In the very short term, the European Spaceport in French Guiana (CSG) will welcome new kinds of missions and launchers, such as Ariane 6, micro-launchers or reusable vehicles, and must prepare to operate them. At the same time, the launch safety process must be improved in order to maintain flight safety standards and to respect the requirements of the French Space Operation Act (FSOA [1]) regarding the new risks induced. The Flight Safety Department at CSG has been working on the development of new methods to fit these upcoming challenges while enabling the best possible protection to people, the environment and infrastructures. These concepts will be implemented with the arrival of the new Operations Centre (CDO).Although the flight termination decision remains on a human authority, the process to evaluate the dangerousness of a mission is optimized in order to gain reactivity and effectiveness. As presented at the 73rd IAC [2], this optimization of methods relies on both decreasing the number of operators within the flight safety team during launch operations and on implementing decision-aiding algorithms to better characterize the launcher condition status at any time. This implies a new distribution of the responsibilities between the safety operators and a redesign of the systems in the future organization at CSG.A large test campaign has already been conducted with the participation of all flight safety officers in order to collect data covering different fields [2]: personal and collective impressions, level of comfort, trust in the new concepts and comparison to the current process, amongst others. In follow-up of this study, to consolidate and validate the operability of the presented concepts and methods, the impacts of this new organization on the flight safety officers have been evaluated in order to apprehend the main changes compared to the current organization. In addition, a specific evaluation was performed in order to study the operator behaviour during various simulations of dangerous-case scenarios in which the launcher trajectory or on-board parameters deteriorated. The most critical cases were analysed in order to measure the reaction times before terminating the flight, with respect to different configurations of launcher abnormality. When comparing the behaviour and the reaction time of operators between the current and the future organization, we obtained conclusive results that are presented in this paper. These results will help to determine and demonstrate the efficiency of the new suggested method for the future flight safety organization at the CSG New Generation. The test campaign presented in this paper was possible following significant ergonomics choices regarding both the flight safety room configuration and the operator HMI layout. Indeed, the enhancement of flight safety operations has been enabled by a careful selection of decision-aiding algorithms and logical equations, however the study determining the most adequate position of HMI elements has also played a major role in the safety officers’ ability to operate the new concepts.This paper will present the results of the test campaign based on initial ergonomic studies enabling this major change in the organization of the flight safety team within the future CSG.

Zero-G Lab: A multi-purpose facility for emulating space operations

During orbital rendezvous, the spacecraft typically approach in the same orbital plane, and the phase of the orbit eventually aligns. Potential rendezvous and docking missions need to be emulated and tested in an on-ground facility for micro-gravity research prior to meeting the harsh conditions of space environment. For orbital docking, the velocity profile of the two spacecraft must be matched. The chaser is placed in a slightly lower orbit than the target. Since all these tasks are quite complex and the realization of space missions are very expensive, any space-related hardware or software’s performance must be tested in an on-ground facility providing zero gravity emulation before initiating its operation in space. This facility shall enable emulation conditions to mimic pseudo zero gravity. It is of critical importance to be equipped with all the necessary ”instruments and infrastructure” to test contact dynamics, guidance, navigation and control using robotic manipulators and/or floating platforms. The Zero-G Laboratory at the University of Luxembourg has been designed and built to emulate scenarios such as rendezvous, docking, capture and other interaction scenarios between separate spacecraft. It is equipped with relevant infrastructure including nearly space-representative lightning conditions, motion capture system, epoxy floor, mounted rails with robots, capability to integrate on-board computers and mount large mock-ups. These capabilities allow researchers to perform a wide variety of experiments for unique orbital scenarios. It gives a possibility to perform hybrid emulations with robots with integrated hardware adding pre-modeled software components. The entire facility can be commanded and operated in real-time and ensures the true nature of contact dynamics in space. The Zero-G Lab also brings great opportunities for companies/startups in the space industry to test their products before launching the space missions. The article provides a compilation of best practices, know-how and recommendations learned while constructing the facility. It is addressed to the research community to act as a guideline to construct a similar facility.

AI-Centric secure outer space operations

This article critically assesses the transformative role of Artificial Intelligence (AI) in military operations, focusing on terrestrial warfare and outer space security. It offers four main points of discussion: 1) An evaluation of AI applications in terrestrial warfare, using real-world technologies such as Project Maven and BAE Systems’ Taranis; 2) an examination of AI’s contributions and risks in the field of cybersecurity; 3) an in-depth look at AI’s growing influence in space security, including technical aspects of systems like the U.S. Space-Based Infrared and the European Data Relay System; 4) an analysis of the ethical and policy challenges associated with AI deployment, informed by the author’s viewpoints on the necessity of international regulation. Drawing from various case studies and expert consultations, the article highlights AI’s capabilities in enhancing decision-making and operational efficiency while discussing the ethical and technical complexities it introduces. The study concludes by offering nuanced recommendations for responsibly integrating AI into military strategies and policies, especially those concerning space security. The aim is to inform and guide military professionals and policymakers by providing actionable insights for responsible decision-making in AI-augmented conflict scenarios on Earth and in space.

A multimodal multi-objective evolutionary algorithm with two-stage dual-indicator selection strategy

Multimodal multi-objective problems (MMOPs) arise frequently in the real world, in which multiple Pareto optimal solution sets correspond to the same point on the Pareto front. To find more equivalent Pareto sets, numerous multimodal multi-objective evolutionary algorithms (MMEAs) based on niching have been developed. However, traditional niching methods have parameter sensitivity issues. Moreover, most existing MMEAs always perform diversity maintenance operations in the decision space and the objective space sequentially based on preferences, without considering a diversity maintenance operation that takes into account both the decision space and the objective space simultaneously. To tackle these challenges, a multimodal multi-objective evolutionary algorithm with two-stage double indicator selection strategy (MMEA-TDI) is developed. First, a dual-indicator with adaptive niche radius is developed to estimate the crowding status of the population. Then, a diversity-based mating selection is suggested to select well-distributed parents for mating. Furthermore, the environmental selection is performed in two stages. In the first stage, a parameter-free automatic niching technique based on clustering is adopted to well balance diversity and convergence in the decision space, while a double indicator selection strategy is performed for maintaining diversity in both decision and objective spaces in the second stage. To assess the performance of the proposed algorithm, extensive experiments are conducted on the well-known benchmark functions, in comparison with eight state-of-the-art MMEAs. Experimental results demonstrate that the proposed algorithm is significantly superior to the competing algorithms.

Impact of Higher Airspace Operations on Air Traffic in Europe

Historically, higher airspace has been used for military exercises and as transit for space vehicles. Riding on commercial space operations’ coattails, more and more vehicles are under development that will make use of higher airspace resources. This will lead to increasing interactions with conventional air traffic since these new vehicles will have to transit through lower airspaces. The management of these operations is necessary to ensure the safe and practicable shared usage of these airspaces. This paper outlines an assessment of the impact of higher airspace operations on conventional air traffic in Europe. Initially, a synthesis of possible use cases was performed, and demand scenarios were developed that served as input to a fast-time simulation. The impact on air traffic was measured by means of flight efficiency parameters. The simulation results showed that the impact is dependent on the type of operation. High-altitude platform system flights and orbital launches cause the largest deviations in flight distance, flight duration and fuel consumption. Higher airspace operation parameters, including location, time, and duration, strongly affect the impact on the conventional air traffic.

THE CONVENTION ON INTERNATIONAL LIABILITY FOR DAMAGE CAUSED BY SPACE OBJECTS FROM THE HUMAN RIGHTS PERSPECTIVE – SELECTED ASPECTS

In spite of the Convention on International Liability for Damage Caused by Space Objects being in force for a long time, it has not as yet been analysed from a human rights perspective. While at the beginning of the space age activities in space were associated only with states, the progress on humankind in the conquest of space has significantly changed that. Nowadays, the role of individuals in space operations is growing. The well-established human rights law on Earth also needs to be reflected in regulations concerning outer space. This paper assesses selected aspects of the Convention from the human rights perspective. The analysis encompasses the definition of “damage” along with the possible amount of compensation due to individuals and the different aspects of procedural guarantees available for them. The paper presents two possible routes for obtaining compensation: one through diplomatic channels and another using national channels of launching states. This study offers a de lege ferenda proposal to appeal to state parties to introduce internal regulations aimed at avoiding human rights infringements. Domestic law systems may create legal provisions that may fill the gaps caused by the Convention’s limitations, e.g. by introducing an appropriate insurance system for space passengers.

THE CONCEPT OF LONG – TERM SUSTAINABILITY OF OUTER SPACE ACTIVITIES AND THE INTERNATIONAL RESPONSIBILITY OF STATES FOR SPACE ACTIVITIES

The concept of long-term sustainability of outer space activities is based on rational assumptions regarding outer space as a limited resource, which will inevitably shrink in the long term if States do not take appropriate preventive measures. The arguments for this are all the stronger as it concerns a real threat to the safety of space operations, and what is more, to their continuation in the future. The legal status of outer space determines the responsibility of States for the activities of both governmental and non-governmental entities. The UN COPUOS Guidelines for the Long-term Sustainability of Outer Space Activities strongly remind of this. This is an important element of this document, which should be considered not only in the context of liability for damage caused as a result of space activities, but also in the context of liability for violating the principles adopted in the key treaty of international space law, which is the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies of 27 January 1967. The main purpose of this article is to present the assumptions of the concept and, in their light, to refer to its structural treaty connotations in the field of generally recognized international responsibility of the State for space activities. The study is also intended to show workable solutions adopted in national law that implement the COPUOS Guidelines, as a necessary and inevitable direction of national activity of countries wanting to explore and use outer space safely and responsibly.

DASS: Differentiable Architecture Search for Sparse Neural Networks

The deployment of Deep Neural Networks (DNNs) on edge devices is hindered by the substantial gap between performance requirements and available computational power. While recent research has made significant strides in developing pruning methods to build a sparse network for reducing the computing overhead of DNNs, there remains considerable accuracy loss, especially at high pruning ratios. We find that the architectures designed for dense networks by differentiable architecture search methods are ineffective when pruning mechanisms are applied to them. The main reason is that the current methods do not support sparse architectures in their search space and use a search objective that is made for dense networks and does not focus on sparsity. This paper proposes a new method to search for sparsity-friendly neural architectures. It is done by adding two new sparse operations to the search space and modifying the search objective. We propose two novel parametric SparseConv and SparseLinear operations in order to expand the search space to include sparse operations. In particular, these operations make a flexible search space due to using sparse parametric versions of linear and convolution operations. The proposed search objective lets us train the architecture based on the sparsity of the search space operations. Quantitative analyses demonstrate that architectures found through DASS outperform those used in the state-of-the-art sparse networks on the CIFAR-10 and ImageNet datasets. In terms of performance and hardware effectiveness, DASS increases the accuracy of the sparse version of MobileNet-v2 from 73.44% to 81.35% (+7.91% improvement) with a 3.87× faster inference time.

베트남음식레스토랑의 식공간 디자인특성분석

This study aims to understand the formative characteristics of Vietnamese restaurants and provide information and knowledge necessary for the research and operation of Vietnamese food spaces. For this research purpose, 10 Vietnamese restaurants with high awareness and preference in Hanoi and Ho Chi Minh City were selected, visited, and investigated. The analysis was conducted through the photographs taken, prior research, and literature, and the following results were obtained. (1) Since the old small urban building is used as a single store, it is likely that the entire interior space can be configured in various ways. (2) Since the store usually uses the first floor, it is possible to form a more flexible store space by configuring the entry space and opening it with the upper floor. (3) It provides a spatial experience to communicate with the surrounding environment through various mediation spaces such as verandas, terraces, porches, and outdoor courts. (4) Although reinforced concrete structures are commonly used, handcrafted elements are used as construction auxiliary materials everywhere, showing the modern and traditional contrast and harmony between planes and lines. In recent years, the number of Vietnamese restaurants has been increasing in Korea, and the results of this study are expected to create many excellent food spaces that can fully show Vietnam's identity as well as Vietnamese food.

3D Printing of Batteries from Lunar and Martian Regolith

To maximize the sustainability of future space missions, the utilization of local resources available on the Moon or Mars, also known as in-situ resource utilization (ISRU), is crucial to develop infrastructures such as habitation modules, power generation, and energy storage facilities.1–3 This work presents a perspective aiming to introduce the future of batteries manufacturing on the lunar and martian environment from ISRU materials. Based on the composition of the lunar and martian soil,4–7 the choice of the battery technology and materials for the different battery components (electrodes, electrolyte, current collectors and packaging) are examined. The motivations for selecting additive manufacturing technologies as a unique approach to support human operations in space, on the surface of the Moon or Mars, and any other locations where cargo resupply is not as readily available, as well as the need for high resolution multi-material printing methods, are discussed. Additive manufacturing paves the way to three-dimensional rechargeable battery architectures with enhanced specific surface area, three-dimensional ion diffusion, and improved power performances, while also allowing the development of shape-conformable batteries to maximize the energy storage within the final application.8–15 The in-space additive manufacturing process of shape-conformable batteries using in-situ resources is in direct alignment with the NASA’s objectives to demonstrate in-space autonomous manufacturing and assembly of complete systems by 2030, and to enable Humans survival, explore deep space, and visit planetary surfaces by 2040.16 Such initiatives also contribute to reducing power-related payload weight and volume in future missions, thus reducing the risk for long term Moon or even Mars missions where rapid resupply will be logistically infeasible. In this context, this presentation will provide a perspective of what is required to 3D print batteries on lunar and martian surfaces,17 an overview of our ongoing project dedicated to AM of sodium-ion batteries from resources available on the Moon and Mars and our recent work on 3D printing of TiO2 negative electrode material by means of the vat photopolymerization process.18 (1) Anand, M. et al. A Brief Review of Chemical and Mineralogical Resources on the Moon and Likely Initial in Situ Resource Utilization (ISRU) Applications. Planet. Space Sci. 2012, 74 (1), 42–48.(2) Edmunson. Building a Sustainable Human Presence on the Moon and Mars. New Horizons Summit.(3) McMillon-Brown, L. et al. What Would It Take to Manufacture Perovskite Solar Cells in Space? ACS Energy Lett. 2022, 7 (3), 1040–1042.(4) Heiken, G. et al. Lunar Sourcebook: A User’s Guide to the Moon; CUP Archive, 1991.(5) Dreibus, G. et al. Lithium and Halogens in Lunar Samples. Philos. Trans. R. Soc. Lond. A 1977, 285 (1327), 49–54.(6) Taylor, G. J. The Bulk Composition of Mars. Geochem. Explor. Environ. Analy. 2013, 73 (4), 401–420.(7) Yoshizaki, T. et al. The Composition of Mars. Geochim. Cosmochim. Acta 2020, 273, 137–162.(8) Maurel, A. et al. Highly Loaded Graphite-Polylactic Acid Composite-Based Filaments for Lithium-Ion Battery Three-Dimensional Printing. Chem. Mater. 2018, 30 (21), 7484–7493.(9) Maurel, A. et al. Considering Lithium-Ion Battery 3D-Printing via Thermoplastic Material Extrusion and Polymer Powder Bed Fusion. Additive Manufacturing 2020, 101651.(10) Martinez, A. C. et al. Additive Manufacturing of LiNi1/3Mn1/3Co1/3O2 Battery Electrode Material via Vat Photopolymerization Precursor Approach. Sci. Rep. 2022, 12 (1), 1–13.(11) Maurel, A. et al. Overview on Lithium-Ion Battery 3D-Printing By Means of Material Extrusion. ECS Trans. 2020, 98 (13), 3–21.(12) Maurel, A. et al. Toward High Resolution 3D Printing of Shape-Conformable Batteries via Vat Photopolymerization: Review and Perspective. IEEE Access 2021, 9, 140654–140666.(13) Maurel, A. et al. Ag-Coated Cu/Polylactic Acid Composite Filament for Lithium and Sodium-Ion Battery Current Collector Three-Dimensional Printing via Thermoplastic Material Extrusion. Frontiers in Energy Research 2021, 9 (70). https://doi.org/10.3389/fenrg.2021.651041.(14) Ragones, H. et al. Towards Smart Free Form-Factor 3D Printable Batteries. Sustainable Energy & Fuels 2018, 2 (7), 1542–1549.(15) Egorov, V. et al. Evolution of 3D Printing Methods and Materials for Electrochemical Energy Storage. Adv. Mater. 2020, 32 (29). https://doi.org/10.1002/adma.202000556.(16) Murphy, P. STMD’s New Strategic Framework Update, 2017. https://www.nasa.gov/sites/default/files/atoms/files/336429-508-to5_nac_dec_2017_strategicplanningintegration_tagged.pdf.(17) Maurel, A. et al. What Would Battery Manufacturing on the Moon and Mars Look Like? (submitted).(18) Maurel, A. et al. 3D Printed TiO2 Negative Electrodes for Sodium-Ion and Lithium-Ion Batteries Using Vat Photopolymerization (submitted).

Influence of Opposing Exterior Window Geometry on the Carbon Emissions of Indoor Lighting under the Combined Effect of Natural Lighting and Artificial Lighting in the City of Shenyang, China

According to relevant statistics, the electricity consumption for lighting in university buildings accounts for 20 to 40% of the total energy consumption of the buildings. Lighting energy saving is a key influential factor in achieving a low-carbon campus construction. The electricity consumption for lighting is simultaneously affected by the utilization of natural daylight and artificial lighting schemes. Currently, there is a lack of research regarding the dynamic quantitative correlation between the geometric design of external windows affecting the utilization of natural daylight and carbon emissions. Also, research on the dynamic synergistic impact between natural light utilization and artificial lighting on carbon emissions has not been observed. Hence, there is a lack of quantitative carbon impact prediction and guidance in the early design and actual operation of such spaces. This study took the professional drawing space of a university in the severe cold regions of Shenyang as a prototype. Daylight factor (DF) and spatial daylight autonomy (sDA) were determined using Rhino + Grasshopper and Ladybug + Honeybee for window geometry. DIALux evo simulation was used to analyze the carbon emissions of space operation, followed by correlation analysis and multiple linear regression analysis using SPSS to determine the degree of influence of each window design parameter on the carbon emissions. The window-to-floor ratio (WFR), window-to-wall ratio (WWR), windowsill height (Hws), window width (Ww), and window height (Hw) had inhibitory effects on carbon emissions from daylight-responsive artificial lighting (C), and the influence of different orientations was different. Under the condition of an opposing window, the overall C trend of the professional drawing space was west < east< south < north, and the C of the morning period in each orientation was significantly lower than that in the afternoon period. Taking the frame structure system space with a floor-to-floor height of 4.2 m as an example, within the requirements of WFR and WWR, the C of the west-facing professional drawing classroom with 2.55 m for Hw, 0.75 m for Hws, and 9.6 m for Ww was the smallest. To a certain extent, opening large windows and opening high windows can reduce the C of the space.

(Invited) Leveraging Magnetohydrodynamic Mechanisms for Stable and Efficient Microgravity Electrolysis

Water electrolysis is the fundamental chemical process for oxygen and hydrogen production in space. It is widely employed in modern environmental control and life support systems, propulsion technologies, and high-density energy storage devices. Furthermore, future interplanetary missions are likely to employ water as a commodity acquired and processed by In Situ Resource Utilization (ISRU) methodologies to produce propellants, thereby reducing vehicle launch mass.The absence of buoyancy results in major technical challenges for the operation of electrolytic cells in low gravity. The need to detach and collect oxygen and hydrogen bubbles has been traditionally addressed by means of forced water recirculation loops. However, this leads to complex, inefficient, and unreliable liquid management devices composed of multiple elements and moving parts. Two distinct magnetohydrodynamic (MHD) mechanisms may instead be employed to induce phase separation: diamagnetic, and Lorentz forces. The former arises in the presence of strong, inhomogeneous magnetic fields and results in a magnetic buoyancy effect. The latter is a consequence of the imposition of a magnetic field to the current generated between two electrodes. Both approaches can potentially lead to a new generation of electrolytic cells with minimum or no moving parts, hence enabling the human deep space operations with minimum mass and power penalties.Dedicated microgravity experiments are required to study these novel magnetically enhanced electrolysis concepts. This presentation introduces the fundamentals of both methods and discusses the experimental design and results from several experimental campaigns at ZARM’s drop tower and Blue Origin’s New Shepard. The performance of representative electrolytic cells subject to different MHD regimes is addressed from an electrochemical and fluid dynamic perspectives. It is demonstrated that the MHD force effectively detaches and collects gas bubbles in microgravity while increasing the current density and improving the stability of the electrolytic cell. Ultimately, this opens the door for the development of highly-efficient space electrolytic cells with applications to human and robotic space exploration.

High-Density Pixel Imaging Sensor Readout Electronics for Space Applications: A Design Overview

With the specialization of VLSI ASICs for front-end signal processing electronics, the customization of the control back-end electronics (BEE) has become critical to fully deploy the ASIC performance. In the context of space operations, with typical constraints on power and reliability, the design and qualification of such integrated systems present significant challenges. In this paper, we review the design and performance of the BEE systems after two years of operations in low Earth orbit (LEO); these systems read out the custom ASICs inside the gas pixel detectors, which are located at the heart of the imaging X-ray polarimetry explorer (IXPE), a NASA-ASI small explorer mission designed to measure X-ray polarization in the 2–8 keV energy range.

Atlas of historical and proposed nuclear devices and power systems in the Earth-Moon System and wider Solar System

The 2010s witnessed a renewal in international interest of space operations extending outside geosynchronous orbit to encompass the cislunar environment and beyond with invigorated U.S., Chinese, and Russian lunar mission initiatives; planned commercial lunar projects; and coalescing international efforts to reach Mars and push deeper into the Solar System. With the space beyond the near-Earth orbital regimes likely to become competitive and congested in the coming decades, reliable and high-yield means of generating power and propulsion will be needed to enhance mission assurance and operational responsiveness. Nuclear systems represent a promising technology with a rich heritage and provenance of space-based applications to satisfy emerging requirements for electrical power and propulsive impulse for long-term human development of the Earth-Moon system and its planetary neighbors. In this work, an atlas for defining the varying historical or proposed uses of nuclear power in space operations and exploration is presented according to spatial zone within the Earth-Moon and wider Solar System. Depending on the spatial zone, nuclear power will be discussed with respect to applications such as electrical power generation, propulsion, resource extraction, and weapon testing and employment for the space control and planetary defense missions.

In-situ enhanced anchor-free deep CNN framework for a high-speed human-machine interaction

Human-Robot Interaction (HRI) constitutes a demanding research field that integrates artificial intelligence, informatics, robotics, engineering, and human-machine interaction. In the present era, there is an increased focus on natural user interfaces, with particular attention to gestural modalities. This leads to the coordination of modern robotic systems, where real-time integration and interpretation of manual gestures play a vital role in facilitating effective manipulation. Hand gesture recognition holds a crucial role in the field of machine vision, perhaps greatly exacerbated with varying lighting conditions and backgrounds. In this paper, first an Enhanced Anchor-free Network (EAF-Net) is proposed to perform hand gesture recognition in real-time. The EAF-Net is deep single-stage Convolutional Neural Network (CNN) based architecture. The Custom Precise Prediction Function (CPPF) is utilized for a continuous recognition of a specific gesture from a video feed. Then, the 6-axis collaborative Robot is manipulated using the predicted gesture. The EAF-Net model utilizes the Enriched Hourglass as a backbone feature extraction network. The proposed EAF-Net model undergoes training and assessment using the MITI HD-II dataset. The performance of the model is also analyzed for the standard benchmark datasets (NUSHP-II and Senz-3D). The evaluation of the EAF-Net model’s performance spans a range of IoU values from 0.5 to 0.95. The EAF-Net model led to higher precision values (AP0.5) as 99.22%, recall values (AR0.5) as 98.20%, and F1-Score0.5 as 98.64% on the MITI HD-II dataset. The EAF-Net model consumed a prediction time of 259 ms on NVIDIA Jetson Nano Processor and 14 ms on NVIDIA Titan X GPU. It aided in implementing a portable high-speed 6-axis Robot control framework to pick and place operation in 3D space. The robot would be able to imitate human hand activities such as hand rotation, hand tilting, picking and arranging items, and so on in the near future. Further reduction in prediction time of the model on the portable processors (NVIDIA Jetson Nano, Raspberry-Pi) could enhance the speed of the Human Machine Interaction process.