Results 41 to 50 of about 4,477,022 (227)

Cooperative control with adaptive graph Laplacians for spacecraft formation flying [PDF]

49th IEEE Conference on Decision and Control (CDC), 2010
This paper investigates exact nonlinear dynamics and cooperative control for spacecraft formation flying with Earth oblateness (J 2 perturbation) and atmospheric drag effects. The nonlinear dynamics for chief and deputy motions are derived by using Gauss' variational equation and the Euler-Lagrangian formulation, respectively. The proposed cooperative
Insu Chang, Soon-Jo Chung, Lars Blackmore   +2 more
openaire   +3 more sources

Static Drainage H2/O2 PEM Fuel Cells Enabled by Water Transport Plates: Pore‐Scale Design and Transport Mechanisms

Advanced Science, EarlyView.
The WTP is a key component of static drainage PEMFCs, enabling cathode water removal and gas sealing through capillary forces. This work investigates the mechanisms governing WTP drainage and sealing performance and develops predictive approaches for WTP design optimization.
Mengdi Guo, Diankai Qiu, Dong Zhu, Linfa Peng   +3 more
wiley   +1 more source

Passivity-Based Control with Disturbance Observer of Electromagnetic Formation Flight Spacecraft in the Port-Hamiltonian Framework

Applied Sciences
Satellite formation flying technology currently represents a focal point in space mission research. Traditional spacecraft payload performance and lifespan are often constrained by propellant limitations.
Jiaming Wang, Qingrui Zhou, Wei Zheng, Jiang Shao   +3 more
doaj   +1 more source

Spontaneous Cyclic Levitation of Glycerol‐Water Droplets at Low Pressures

Advanced Science, EarlyView.
Under low pressure, a minute glycerol addition transforms the chaotic dynamics of freezing water droplets into cyclic levitation. Freeze‐concentration preserves liquid pathways that relax expansion‐induced stress, while freezing point depression weakens asymmetric vaporization recoil.
Chen Xu, Renjie Hua, Wei Ma, Fuqiang Chu, Dong Liang, Xueshi Li, Qirui Zhang, Yuan Dong, Xuehu Ma, Xiao Yan, Shuhuai Yao   +10 more
wiley   +1 more source

Spacecraft formation flying orbital control for earth observation mission

Scientific African
Synthetic Aperture Radar (SAR) sensors have gained much attention for multiple civil use cases, where NewSpace startups have launched and planning to launch sensors to orbit to harvest the unique capabilities of SAR for the Earth Observation (EO) market.
Ahmed Alzubairi, Abdullah Tameem, Belkacem Kada   +2 more
doaj   +1 more source

Temperature Dependence of Space Charge Retention in Bulk Acrylic

Advanced Science, EarlyView.
The temperature dependence of space charge stability in electron‐charged bulk acrylic is probed by thermal manipulation. Charge carrier mobility is observed to be phonon‐dependent, which can be restricted indefinitely below a critical temperature.
Bryson C. Clifford, Kathryn M. Sturge, Noah Hoppis, Emily H. Frashure, John Cumings, Timothy W. Koeth   +5 more
wiley   +1 more source

Autonomous Formation Flying at DLR's German Space Operations Center (GSOC) [PDF]

, 2007
In the upcoming years, significant changes in the profile of satellite missions are expected as scientists and managers want to benefit from multi-satellite missions.
Gill, Eberhard, Rupp, Thomas, D'Amico, Simone, Montenbruck, Oliver   +3 more
core  

Coordinated Attitude Control of Spacecraft Formation Flying via Fixed-Time Estimators under a Directed Graph

Remote Sensing, 2022
This paper mainly studies the distributed fixed-time coordinated attitude tracking control problem of spacecraft formation with a dynamic leader spacecraft under directed communication topology.
Zhanjie Zhou, Yan Wang
doaj   +1 more source

Spacecraft Formation Flying in Eccentric Orbits

JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 2008
Formation flight of spacecraft in eccentric orbits is considered in this paper. Symmetry of the eccentric orbits is assumed in a relative formation orbit, and under this assumption, relations of initial conditions in formation flight are derived. Some characteristic orbits are obtained from these relations, such as an orbit where a deputy spacecraft ...
Yamada, Katsuhiko, Shima, Takeya, Jikuya, Ichiro, Yoshikawa, Shoji   +3 more
openaire   +2 more sources

Predicting Performance of Hall Effect Ion Source Using Machine Learning

Advanced Intelligent Systems, Volume 7, Issue 3, March 2025.
This study introduces HallNN, a machine learning tool for predicting Hall effect ion source performance using a neural network ensemble trained on data generated from numerical simulations. HallNN provides faster and more accurate predictions than numerical methods and traditional scaling laws, making it valuable for designing and optimizing Hall ...
Jaehong Park, Guentae Doh, Dongho Lee, Youngho Kim, Changmin Shin, Su‐Jin Shin, Young‐Chul Ghim, Sanghoo Park, Wonho Choe   +8 more
wiley   +1 more source