Results 31 to 40 of about 318 (178)

3D Variations in Viscosity Reconcile the Strength of the Lower Mantle Inferred From Glacial Isostatic Adjustment and Mantle Convection

Geophysical Research Letters, Volume 53, Issue 9, 16 May 2026.
Abstract A widely accepted global model of glacial isostatic adjustment (GIA) is based on ICE‐6G ice loading and 1D‐viscosity model VM5a, a viscosity profile which remains at odds with mantle convection constraints such as from geoid modeling. We explore 3D‐viscosity variations in models of GIA and show that a model with lateral viscosity variations ...
A. Bellas‐Manley, K. Kang, T. W. Becker, R. S. Nerem   +3 more
wiley   +1 more source

Evolutionary Approach to Lambert’s Problem for Non-Keplerian Spacecraft Trajectories

Aerospace, 2017
In this paper, we use differential evolution (DE), with best-evolved results refined using a Nelder–Mead optimization, to solve boundary-value complex problems in orbital mechanics relevant to low Earth orbits (LEO).
David W. Hinckley, Darren L. Hitt
doaj   +1 more source

An Earth-Moon Transfer Trajectory Design and Analysis Considering Spacecraft’s Visibility from Daejeon Ground Station at TLI and LOI Maneuvers [PDF]

Journal of Astronomy and Space Sciences, 2010
The optimal Earth-Moon transfer trajectory considering spacecraft’s visibility from the Daejeon ground station visibility at both the trans lunar injection (TLI) and lunar orbit insertion (LOI) maneuvers is designed.
Jin Woo, Young-Joo Song, Sang-Young Park, Hae-Dong Kim, Eun-Sup Sim   +4 more
doaj   +1 more source

Fast Switch and Spline Function Inversion Algorithm with Multistep Optimization and k-Vector Search for Solving Kepler’s Equation in Celestial Mechanics

Mathematics, 2020
Obtaining the inverse of a nonlinear monotonic function f(x) over a given interval is a common problem in pure and applied mathematics, the most famous example being Kepler’s description of orbital motion in the two-body approximation.
Daniele Tommasini, David N. Olivieri
doaj   +1 more source

High Geomagnetic Reversal Frequency During the Middle to Late Ediacaran (∼570 Ma) Constrained by Integrated Magneto‐ and Cyclostratigraphy

Journal of Geophysical Research: Solid Earth, Volume 131, Issue 4, April 2026.
Abstract The Ediacaran–Cambrian (∼635–539 Ma) geomagnetic field is characterized by unusually high reversal rates and markedly weakened field strength. Estimates of these reversal frequencies can reveal key aspects of deep Earth dynamics and their potential influence on surface environments and early complex life.
J. W. L. Afonso, R. M. Rocha, D. R. Franco, N. B. Dos Santos, C. G. Leandro, P. Franceschinis, A. E. Rapalini, M. J. Arrouy, L. E. Gómez‐Peral, D. G. Poiré, S. Caetano‐Filho, H. D. Brito, R. I. F. Trindade   +12 more
wiley   +1 more source

Adaptive Saturated Neural Network Tracking Control of Spacecraft: Theory and Experimentation

International Journal of Aerospace Engineering, 2019
An adaptive saturated neural network (NN) controller is developed for 6 degree-of-freedom (6DOF) spacecraft tracking, and its hardware-in-the-loop experimental validation is tested on the ground-based test facility. To overcome the dynamics uncertainties
Kewei Xia, Taeyang Lee, Sang-Young Park
doaj   +1 more source

Generating Stable and Metastable Critical Points in Uncertain Systems via Flow‐Based Models

Expert Systems, Volume 43, Issue 3, March 2026.
ABSTRACT This work proposes the use of conditional flow‐based generative models to learn an approximation of the distribution of the critical points of a cost function. This approximation is used to incrementally identify all critical points, in the feasible domain of said function, by iteratively alternating the sampling of the distribution and the ...
Callum Wilson, Massimiliano Vasile
wiley   +1 more source

Development of a Hardware-In-Loop (HIL) Simulator for Spacecraft Attitude Control Using Momentum Wheels [PDF]

Journal of Astronomy and Space Sciences, 2008
In this paper, a Hardware-In-the-Loop simulator to simulate attitude control of spacecraft using momentum wheels is developed. The simulator consists of a spherical air bearing system allowing rotation and tilt in all three axes, three momentum wheels ...
Dohee Kim, Sang-Young Park, Jong-Woo Kim, Kyu-Hong Choi   +3 more
doaj   +1 more source

Real-Time Determination of Relative Position Between Satellites Using Laser Ranging [PDF]

Journal of Astronomy and Space Sciences, 2012
We made a study on real-time determination method for relative position using the laser-measured distance data between satellites. We numerically performed the determination of relative position in accordance with extended Kalman filter algorithm using ...
Shinwon Jung, Sang-Young Park, Han-Earl Park, Chan-Deok Park, Seung-Woo Kim, Yoon-Soo Jang   +5 more
doaj   +1 more source

Predicting and Clustering Attitude‐Induced Divergence in Cross‐Array AOA Measurements for LEO Satellites

IET Radar, Sonar &Navigation, Volume 20, Issue 1, January/December 2026.
Example of cluster identification of attitude configurations to avoid in the attitude space (in terms of angles of roll, pitch and yaw) for a payload composed by a cross antenna array with angle of arrival technology for CubeSats platforms. ABSTRACT Satellite geolocation of radio‐frequency emitters increasingly relies on compact angle‐of‐arrival (AOA ...
Marcello Asciolla, Angela Cratere, Francesco Dell’Olio   +2 more
wiley   +1 more source