Engineering Commons^™

Toward Public Access To On-Orbit Propulsion Data From Equuleus: Preparing Real Flight Data For Community Use, Hiroyuki Koizumi, Isamu Moriai, Hokuto Sekine, Keita Nishii, Mariko Akiyama, Shintaro Nakajima, Yosuke Kawabata, Yasuho Ataka, Shunichiro Nomura, Ryota Fuse, Ryu Funase

Small Satellite Conference

EQUULEUS is a 6U lunar exploration CubeSat, jointly developed and operated by the University of Tokyo and the Japan Aerospace Exploration Agency (JAXA). It was launched in November 2022 by the Space Launch System (SLS) into a lunar transfer orbit and achieved insertion into a trajectory toward the Earth–Moon Lagrange region through multiple lunar flybys using its onboard water resistojet propulsion system AQUARIUS. The EQUULEUS primary mission is the demonstration of trajectory control technology in the Sun-Earth-Moon region for the first time by a nano-spacecraft.

Tailored Catalysts For Space Propulsion, Florian Harth, Kathy Bynum, Ilaria Longobardo, Hendrik Spod, Ingo Gräf, Alexander Bier, Hans-Jörg Wölk

Small Satellite Conference

Why catalysts matter in space propulsion

Chemical propulsion systems remain indispensable for satellite attitude control, orbit correction and collision avoidance maneuvers due to their reliability and high specific impulse. In monopropellant thrusters, the catalyst initiates the rapid decomposition of the propellant, generating hot reaction gases that produce thrust without external ignition. Catalyst performance and especially catalyst stability therefore directly determine ignition reliability, response time, thermal stability and operational lifetime of the propulsion system.

Heraeus Precious Metals provides heterogeneous catalysts tailored for space propulsion by combining precious metal chemistry, support engineering and scalable manufacturing to meet the demanding requirements of aerospace …

Twinning The On-Orbit Power Behavior Of Small Satellites Using Time-Domain Solar And Load Modeling, Nithin Krishnan S S, Vishnupriya P K, Vishnu Unnikrishnan, Jr-Chiun Roger Tsai, Tensae Ali, Jesmin Jose, Athira B S

Small Satellite Conference

Accurate estimation of on-orbit power availability under dynamic attitude conditions is critical to the reliable design of small satellite electrical power subsystems. During tumbling, detumbling, and mode transitions, rapid variations in solar incidence, eclipse exposure, and subsystem demand introduce strong temporal fluctuations that conventional static or orbit-averaged budgeting cannot capture.

This work presents a modular, time-domain power budgeting framework that models the coupled evolution of power generation, consumption, and energy storage under near-realistic attitude and operational conditions. Solar generation is computed from the time-varying Sun–spacecraft geometry for a multi-panel spacecraft, with per-panel MPPT, deployment state, angle-of-incidence effects, and eclipse …

Water-Floating Experimental Validation Of Magnetic Decoupling Strategies For Electromagnetic Formation Flight Using Palm-Sized Satellites, Hideki Yoshikado, Atsushi Noda, Daisuke Wakao, Takuya Koiso, Masaru Ishida, Shogo Saito, Korehito Suzaki, Juichi Takahashi, Yuta Yamaguchi

Small Satellite Conference

Goal: a distributed space antenna built from 10,000+ palm-sized satellites, operating together as a single phased-array antenna for direct-to-device communication from orbit [1, 2].

Electromagnetic Formation Flight (EMFF) generates magnetic forces and torques between satellites by controlling their coil currents, enabling propellant-free control of relative position and attitude [3, 4, 5].

However, every coil interacts with every other coil, so unwanted pairs must be magnetically decoupled. Multi-satellite ground validation is also difficult: air-bearing facilities limit the number of units and the test area [6, 7].

This work presents a water-floating testbed and a ten-satellite experiment comparing two magnetic decoupling strategies.

Zerodur®: Comprehensive Data Enables The Reliability Of Evidence-Based Design, Dustin Ruth, Florian Gollier, Jesse Bonfeld, Dustin Ruth, Janina Krieg, Thomas Westerhoff, Tony Hull, Jacqueline Caraballo

Small Satellite Conference

ZERODUR® is a glass-ceramic formulated for high-performance optics under imperfect temperature control. Crystallites in a glass matrix balance expansion: crystals shrink while residual glass expands, preserving geometry at fine scale.

This yields the lowest passive thermal response of any optical material-enabling high-contrast, high-resolution, low-scatter imaging and minimal transmission leakage for SmallSat telescopes.

Autongc: One Small High-Fidelity Testbed, One Giant Leap For Autonomous Gn&C At The Moon, Sean Semper, Justin Clavette, Katherine Fowee Gasaway, Hossein Mohammadkhan, Nickalas Cason, Liam Greenlee, Joseph Patton, Grant Ryden, Behnam Azimi, Michael Romeo, Sun Hur Diaz

Small Satellite Conference

Objective:  

• Sustained human presence at Moon/Mars requires autonomous navigation  
• Reduce dependency on human-in-the-loop ground control  
• Enable onboard rapid GN&C in cislunar environment  
• Support multiple measurement types for robust navigation 

A Feasibility-Aware Attitude Trajectory Planner For Small Satellites, Patrick Mckeen, Niclas Scheuer, Kerri Cahoy

Small Satellite Conference

Spacecraft attitude control traditionally requires extensive per-mission engineering—hand-tuned gains, mission-specific mode logic, and conservative operating envelopes—that breaks down when on-orbit conditions deviate from ground assumptions. This is especially costly for small satellites, where limited ground support makes autonomous adaptability essential. We present a feasibility-aware attitude trajectory planner that replaces this hand-engineered stack with continuous planning from a digital twin: less a new feedback law than a different division of labor, in which the mode logic, gain tuning, and desaturation a conventional ADCS builds as separate pieces are instead absorbed into a single optimization.

Built on the ALTRO trajectory optimization algorithm, …

Shining A Spotlight On Maritime Dark Traffic, Alex Da Silva Curiel, Darren Jones, Rob Knight, Rupert Taylor, Leo Jofeh, Sir Martin Sweeting, Per Atle Våland, Simon Flack, Patrik Mandelin, Håkon Heier

Small Satellite Conference

The ability to support Maritime Domain Awareness from space using Synthetic Aperture Radar (SAR) has been successfully demonstrated in the past, however practical challenges in achieving the necessary area coverage, temporal coverage and spatial resolution for a practical system has eluded wider adoption. Yet demand for Maritime Surveillance has increased in recent years, to protect important maritime energy and communications infrastructure, fisheries, and maritime reserves, and especially for maintaining national security and territorial integrity. A novel approach to the SAR payload design solves these challenges, and smallsat technologies have also matured to the point where a High-Resolution Wide-Swath (HRWS) system …

Small Satellite Launches From Japan: Zero Launch Vehicle And Hokkaido Spaceport, Atsuta Keiji, Masaki Fujii

Small Satellite Conference

INTEGRATED LAUNCH SYSTEM

• Easy access to factory in case of last minute iterations
• Simplified logistics
• Launch site is tailored made for ZERO

High-Torque Reaction Wheels For Agile Small Satellites, Thomas Brunsgaard, Matt Carton, Kearney Lackas

Small Satellite Conference

Blue Canyon Technologies has developed a high-torque reaction wheel (RW) product line to meet the growing attitude control demands of next-generation small spacecraft. As small satellites expand into missions requiring rapid retargeting and precise pointing, spacecraft agility is foundational to mission performance. More targets equal more data collection, translating to greater mission insight and revenue generation. 

This paper describes Blue Canyon’s approach to product line architecture that enabled rapid development and deployment of high-torque reaction wheels across multiple size classes. The high-torque variants deliver 0.5 Nm of torque, representing a 2X increase over standard configurations with 60% of the baseline …

Development Of Piezo Fast Steering Mirrors For Fso Inter-Satellite Communication, Frank Claeyssen, Arnaud Gilson, Thomas Maillard, David Ferris, Xavier De Lepine, Oliver Sosnicki, Jocelyn Rebufa, Clément Cote, Francis Bortolaso, Pascal Mexe

Small Satellite Conference

To allow faster communication between satellites, Radio Frequency (RF) links are being replaced by laser optical links, often called Free-Space Optical Communication (FSO). Each satellite embeds several optical communication terminals (OCT), each one needing two Fast Steering Mirrors (FSM) for laser beam fine and fast steering. Thus, for some giant constellations, the total number of FSM can reach up to 100 000 FSM. This New Space market induces not only technical challenges, such as good SWaP, but also industrial challenges, in particular reproducibility, cost-effectiveness and low cost of ownership vs Orbit segment. To address these various FSM needs, CEDRAT TECHNOLOGIES …

Modeling Of Supersonic Wave And Shock Propagation Using The Lattice Boltzmann Method, Timothy P. Schroeder

Beyond: Undergraduate Research Journal

The lattice Boltzmann method (LBM) has emerged as a mesoscopic alternative to traditional Navier-Stokes solvers for modeling fluid dynamics offering advantages in computational efficiency, parallelization, and handling of complex boundaries. Despite these strengths, accurately reproducing compressible, shock-driven phenomena remains challenging. This study investigates the performance of LBM in simulating the Sod shock tube problem, a classical benchmark for compressible flow-using both single and double distribution function formulations across one- and two-dimensional lattice stencils. A MATLAB-based solver was developed to model the flow under isothermal conditions and compared to the analytical solution using the L2 norm error. The one-dimensional models achieved …

Optimizing Ball‐Milled Composites For Fast Energy Release Under Shock Compression, Siva Valluri, Edward Dreizin, Dana Dlott

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Microparticle additives containing both Al fuel and oxidizer, fabricated by arrested reactive milling (ARM), could potentially increase the power of energetic materials such as HMX because they contain premixed fuel and oxidizer. Optimizing shock reactivity requires exploring a vast parametric space encompassing composition, milling parameters that govern microstructural features such as intraparticle voids and fuel-oxidizer mixing, and the resulting inhomogeneous shock reactivity of individual particles. To present our approach, we used a model composition 8Al⋅3CuO, previously optimized for combustion. We milled powders and prescreened different prepared batches using differential scanning calorimetry (DSC) to rule out batches with significant pre-reaction. Then …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Resilience-Oriented Geological Safeguards For Damage Mitigation In Coal Resource Exploitation, Wang Shuangming, Sun Qiang, Yan Meixin, Miao Lintian, Liu Lang, Qiao Junwei, Niu Chao, Geng Jishi, Fang Chenxi, Zhang He, Xiao Lele, Li Shibo

Coal Geology & Exploration

Background Coal remains a fundamental component of China’s energy security system. With the westward shift of coal development and continuous expansion into deeper strata, coal mining is confronted with increasingly complex geological conditions and growing ecological constraints. Geological damage induced by mining disturbance has evolved from isolated geological issues into a coupled Earth-system problem involving the lithosphere, hydrosphere, pedosphere, atmosphere, and biosphere, characterized by uncertainty, hysteresis, concealment, and cross-scale accumulation. Resilience-based damage mitigation emphasizes reducing the probability, intensity, and recovery costs of geological damage through proactive identification, dynamic regulation, damage suppression, and post-disturbance restoration under mining disturbance and external environmental …

Key Technologies And Their Application Of Vertical Large Models For Geological Guarantee In Coal Mining, Liu Zaibin, Fan Tao, Liu Borui, Chen Changyuan, Li Guihong, Li Wei, Jing Xiaotian, Li Xiping, Du Yiming

Coal Geology & Exploration

Background General-purpose large language models (LLMs) have remarkable capabilities in natural language understanding and complex-task reasoning. However, when applied to geological guarantee in coal mining, these models still suffer from several inherent limitations, including insufficient professional geological knowledge, limited insights into industrial terminology, and inadequate integration of engineering logic and rules. Consequently, they face challenges in accurately capturing domain-specific knowledge and reasoning mechanisms required for geological interpretation, early warning of disasters, and decision-making for disaster prevention and control. These issues lead to limited applicability and reliability of general-purpose LLMs. On the other hand, geological guarantee in coal mining involves multi-source …

Mechanisms And Implications Of The Novel Cast Model Of Coal Graphitization, Wang Shaoqing, Zhang Jingzhe, Zhang Xiaomei, Wang Xiaoshuai, Chen Hao, Wang Xiaoling, Li Wu, Tang Yuegang

Coal Geology & Exploration

Objective and Methods Coal graphitization is a multi-stage process with abrupt changes rather than linear evolution. So far, its inherent driving mechanisms have not yet been fully elucidated. Notably, twisted graphene was observed in the process of coal graphitization in 2025, providing a new opportunity to reveal the essence of this structural transformation. Results and Conclusions By combining previous research results, this study proposes a novel coal graphitization model that consists of condensation, alignment, stacking, and twisting (CAST). The four parts of the CAST model are organically integrated, collectively forming a continuous and dynamic evolutionary process. Most especially, no absolute …

Microstructure Evolution Characteristics Of Coal Briquettes During Hot Pressing Carbonization And A Temperature Control Method, Gan Qingqing, Xu Jiang, Peng Shoujian, Cai Guoliang

Coal Geology & Exploration

Objective Coal briquettes used for physical simulations of gas disasters in coal mines generally exhibit low strength and high permeability. To address this challenge, this study developed a new hot pressing process and a temperature control method to optimize the mechanical and seepage performance of coal briquettes. Methods First, an optimal mixing ratio scheme was determined based on the Horsfield close-packing theory, and coal briquettes were prepared at different temperatures using an independently developed hot pressing system. Subsequently, the microstructure evolution patterns of the hot-pressed coal briquettes were characterized using an X-ray diffractometer (XRD), an X-ray photoelectron spectrometer (XPS), a …

3d Geological Modeling And Its Application For Steeply Dipping Coal Seams In The Miquan Area, Xinjiang, Wu Luofei, Li Yong, Zhang Weiqi, Han Yiyang, Zhang Jie, Cao Mingliang, Li Qiang

Coal Geology & Exploration

Background Influenced by multi-stage compression from the North Tianshan and Bogda mountains, the southern margin of the Junggar Basin in Xinjiang exhibits the widespread development of steeply dipping coal seams. The extreme stratigraphic occurrence, combined with complex structural superimposition styles, poses significant challenges to the fine-scale characterization of these coal seams. Correspondingly, the planar and regional distribution patterns of gas content in these coal seams remain poorly understood, rendering it difficult to effectively determine the sweet spots of coalbed methane (CBM). Methods Focusing on the Miquan area, Xinjiang, this study investigated the methodology for 3D geological modeling of representative steeply …

Evolutionary Characteristics And Fine-Scale Zoning Of Overburden Fractures For Pressure-Relief Mining Of Soft Coal Seams, Wang Long, Deng Zhiliang, Zhang Zongxiang, Guo Baohua, Tan Hongchen, Zhao Pengtao, Hu Longsheng

Coal Geology & Exploration

Objective During the mining of coal seam groups, substantial gas is prone to rush into the mining face from adjacent coal seams through interconnected mining-induced fractures. This poses a threat to safe coal mining. Under pressure-relief mining of soft coal seams, their low permeability and high stress sensitivity present challenges to the successive mining of protective and protected coal seams. Specifically, mechanisms behind the overburden fracture evolution remain poorly understood, and it is difficult to identify preferential pathways for gas migration accurately. Methods This study investigated coal seam groups in the Jiahe mining area of Hunan Province as the engineering …

Spatial Topological Configurations Of Cleats And Geometrical Quantitative Characterization Of Matrix Blocks In Deep Coal Seams, Shen Jian, Li Wei, Tian Yongjing, Ma Tianyu, Zhang Hewei, Dong Jiying, Zhu Peipei

Coal Geology & Exploration

Objective Cleats in deep coal seams are characterized by strong heterogeneity, and their topological configurations, as well as their topological relationships with matrix blocks, remain poorly understood. On the other hand, the assumptions regarding the size and geometry of matrix blocks adopted in representative reservoir structure models and numerical simulations do not fully reflect actual reservoir conditions. Methods Deep coal cores collected from the northeastern Ordos Basin were investigated in this study. Using CT scanning and topological theory, a multi-dimensional topological parameter system was established to characterize cleats in deep coal seams. Furthermore, four topological configurations of cleats in deep …

Stable Isotope-Based Origin Identification And Enrichment Zone Division Of Medium- To Low-Rank Coalbed Methane, Wang Qiong, Xu Fengyin, Ren Pengfei, Xu Hao, Lu Pengda, Hu Han, Zhou Siyuan

Coal Geology & Exploration

Objective Medium-to low-rank coalbed methane (CBM) exhibits complex origins with significant vertical differentiation, leading to unclear origin identification and enrichment patterns. This study aims to determine the genetic mechanisms, enrichment patterns, and efficient exploitation pathways of medium- to low-rank CBM. This will help improve the theoretical system for the exploration and exploitation of such CBM. Methods CBM data from 14 typical low- to medium-rank coalfields and coal-bearing basins across the world were comprehensively analyzed, including CBM compositions C₁/(C₂+C₃), carbon and hydrogen isotopes of CH₄ (δ¹³C-CH₄ and δD-CH_{4 …}

Dynamic-To-Static Elastic Parameter Conversion Models For Coals Under Temperature-Pressure Coupling: A Case Study Of The No. 8 Coal Seam In The Daning-Jixian Block, Zhang Wei, Wu Peng, Liu Conghui, Zhang Sidun, Sun Xuedong, Yang Haixing, Ma Zhuang, Shi Rui, Shen Jian

Coal Geology & Exploration

Objective Existing dynamic-to-static elastic parameter conversion models for coals fail to fully account for the actual in situ pressure and temperature conditions of deep reservoirs. This leads to significant deviations in directly evaluating the mechanical properties of reservoirs using log-derived dynamic parameters. To address this challenge, this study investigated dynamic-to-static elastic parameter conversion under the in situ stress and geotemperature conditions of strata. Accordingly, high-precision parameter conversion models were established. Methods This study examined coal samples from the No. 8 coal seam at a burial depth of approximately 1200 m in the Daning-Jixian block along the eastern margin of the …

A Geochemical Evaluation Method For Geological Sweet Spots Of Marine-Continental Transitional Shale Gas: A Case Study Of The Shan$^3_2 $ Sub-Member, Eastern Margin Of The Ordos Basin, Zhu Xingcheng, Li Yong, Lu Jungang, He Qingbo, Li Shuxin, Xiao Zhenglu, Li Xiang, Jiang Qijun

Coal Geology & Exploration

Background China boasts abundant marine-continental transitional shale gas resources. However, marine-continental transitional shales in the country exhibit complex geological conditions characterized by rapid lateral facies transition, vertical superimposition of multiple lithologies, and small single-layer thickness. These characteristics pose a challenge to shale gas sweet spot prediction. Therefore, establishing a sweet spot grading and evaluation system tailored to these shales is of great significance for guiding decision-making in hydrocarbon exploration and supporting large-scale production. Methods Based on core observations, this study systematically evaluated the geochemical characteristics of marine-continental transitional shales in the 3rd submember of the 2nd member of the Permian …

Sources And Occurrence Patterns Of Hydrocarbons In The Surrounding Rocks Of Coal Seams: A Case Study Of The Jurassic Yan'an Formation In The Xinzhuang Mine Field, Longdong Area, Zhang Peng, Chen Dongdong, Zhao Junfeng, Zheng Kaige, Wang Chunxin, Zhou Xingtian

Coal Geology & Exploration

Objective and Methods This study aims to ascertain abnormal hydrocarbon outflows from the surrounding rocks of coal seams in the Jurassic Yan'an Formation within the Xinzhuang mine field in the Longdong area, southwestern Ordos Basin. Based on the fundamental principles of petroleum geology, sedimentology, and coal geology, this study systematically analyzed the sources, occurrence patterns, and primary controlling factors of hydrocarbons in the surrounding rocks of coal seams using methods including core observation, sample analysis, and statistical mapping. Results and Conclusions In the Xinzhuang mine field, hydrocarbon outflows are primarily identified in the floor of the No. 8 coal seam …

Investigating Seepage In Rough Porous Media Fractures Using Fractional Brownian Motion Simulation, Liu Weitao, Kong Debin, Mao Qingfu, Zhao Jiyuan, Gu Yulong, Zhang Xiao

Coal Geology & Exploration

Background Natural rock fractures are often partially filled with permeable materials such as silt and minerals under long-term geological and hydraulic actions, forming complex structures containing unfilled voids. The seepage characteristics of such fractures significantly influence petroleum extraction, mine water prevention, and the stability of underground engineering projects. Methods To reveal the underlying seepage mechanisms, this study generated rough profiles of unfilled voids with different fractal dimensions based on Fractional Brownian Motion. A theoretical expression for the overall permeability of partially filled fractures was derived, and a coupled free flow–porous medium flow numerical model was established. This framework was used …

Key Technologies And Engineering Practices For Green Drainage Of The Jurassic Burnt Rock-Hosted Water In The Shenfu Mining Area, Ji Zhongkui, Mou Lin, Wang Hai, Zhu Kaipeng, Zhao Kaixing, Chen Pan, Xue Xiaoyuan, Han Qiang, He Bo, Wang Fuming

Coal Geology & Exploration

Objective In the northern part of Shaanxi Province, coal mining has led to a pronounced contradiction between coal mining and water conservation, along with a serious threat to China’s ecological redline. These challenges necessitate transforming the mine water drainage pattern in coal mines. Green mine water drainage represents a key approach to achieving coordinated coal-water production in areas containing burnt rocks. Methods Focusing on the conservation-oriented utilization of the Jurassic burnt rock-hosted water in a coal mine within the Shenfu mining area, this study explored a solution to coordinated coal-water production in areas affected by burnt rock-hosted water from the …

Mine Water Storage In Deep Strata: Temperature Responses And The Quantitative Identification Of Primary Permeable Intervals, Xue Jiankun, Wang Shuangming, Zhang Pingsong, Wang Xiaodong, Han Le, Wang Zhizhou, Wang Yutong, Wang Zhibo

Coal Geology & Exploration

Background Storage in deep strata represents an effective approach to treating high-salinity mine water in mining areas of western China. For this technology, the use of directional wells can significantly enhance water injection efficiency, while selecting primary permeable intervals with high injectivity as drilling targets is key to its successful implementation. However, the accurate identification of these intervals in deep strata remains challenging. Methods By analyzing the wellbore temperature variations in the injection well during water injection, a qualitative model was developed to evaluate primary permeable intervals based on wellbore temperature curves. Following the principles of momentum and energy conservation, …

Field Tests On The Capillary Barrier Effect Of Covers For Comprehensive Utilization Of Solid Waste In Waste Dumps, Duan Xu, Chen Chuangchuang, Qiu Xun, Wang Bo, Shi Luyu, Yan Hanyang, Zou Yu, Qu Jin, Hu Zhaojiang

Coal Geology & Exploration

Background In the arid and semi-arid regions of northwestern China, the open-pit waste dumps of mining areas suffer from severe water erosion and the limited water-holding capacities of shallow cover soils. This restricts the ecological restoration of abandoned mine lands. Capillary barrier covers can enhance the water-holding capacities of water storage layers due to the differential hydraulic properties at the interface between fine- and coarse-grained layers. However, both the feasibility of constructing layered covers by mixing solid waste slags from waste dumps with clay and the water regulation performance of the covers are yet to be verified in the field. …

An Experimental Study On The Compressive Shear Failure Characteristics Of Mining-Induced Fractured Rock Blocks In The Absence Of Lateral Confinement And Under Unilateral Confinement, Wang Wenxue, Zhang Shicheng, Li Linyang, Zhang Ruochen, Liang Yankun, Chang Jian, Pan Xuwei, Zhao Guizhang

Coal Geology & Exploration

Objective Rock bridges exert a controlling influence on the deformation, fracture field evolution, and structural stability of mining-induced fractured rock masses. Therefore, it is necessary to investigate their deformation and failure characteristics, as well as the underlying controlling mechanisms, under different confinement conditions. Such investigations will provide theoretical support for the safe mining of underground coal seams and the prevention and control of mining-induced disasters. Methods Mechanical models of fractured rock blocks containing rock bridges were established. Specimens with different fracture dip angles, rock bridge widths, and material strengths were prepared using rock-like materials. Furthermore, an independently developed compressive shear …