Results 11 to 20 of about 795 (205)

Comparative Accuracies of Models for Drag Prediction During Geomagnetically Disturbed Periods: A First Principles Model Versus Empirical Models

Space Weather, 2023
We examine the accuracy of density prediction by the first principles model Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM) developed by the National Center for Atmospheric Research and compare it to the accuracy of three ...
R. L. Walterscheid, M. W. Chen, C.‐C. Chao, S. Gegenheimer, J. Cabrera‐Guzman, J. McVey   +5 more
doaj   +2 more sources

Space flight and central nervous system: Friends or enemies? Challenges and opportunities for neuroscience and neuro-oncology. [PDF]

J Neurosci Res, 2022
Abstract Space environment provides many challenges to pilots, astronauts, and space scientists, which are constantly subjected to unique conditions, including microgravity, radiations, hypoxic condition, absence of the day and night cycle, etc. These stressful stimuli have the potential to affect many human physiological systems, triggering physical ...
Marfia G, Navone SE, Guarnaccia L, Campanella R, Locatelli M, Miozzo M, Perelli P, Della Morte G, Catamo L, Tondo P, Campanella C, Lucertini M, Ciniglio Appiani G, Landolfi A, Garzia E.   +14 more
europepmc   +2 more sources

Fuel Optimization for Low Earth Orbit Maintenance [PDF]

Journal of Astronomy and Space Sciences, 2008
The resolution of Earth images taken from a satellite has close relation with satellite's altitude. If a satellite has lower altitude, it gets a picture having better resolution.
Yong Jae Park, Sang-Young Park, Young-Rok Kim, Kyu-Hong Choi   +3 more
doaj   +1 more source

Novel Structure and Thermal Design and Analysis for CubeSats in Formation Flying

Aerospace, 2021
The CANYVAL-C (CubeSat Astronomy by NASA and Yonsei using a virtual telescope alignment for coronagraph) is a space science demonstration mission that involves taking several images of the solar corona with two CubeSats—1U CubeSat (Timon) and 2U CubeSat (
Yeon-Kyu Park, Geuk-Nam Kim, Sang-Young Park   +2 more
doaj   +1 more source

Laser-based Relative Navigation Using GPS Measurements for Spacecraft Formation Flying [PDF]

Journal of Astronomy and Space Sciences, 2015
This study presents a precise relative navigation algorithm using both laser and Global Positioning System (GPS) measurements in real time. The measurement model of the navigation algorithm between two spacecraft is comprised of relative distances ...
Kwangwon Lee, Hyungjik Oh, Han-Earl Park, Sang-Young Park, Chandeok Park   +4 more
doaj   +1 more source

Fuel-Optimal Altitude Maintenance of Low-Earth-Orbit Spacecrafts by Combined Direct/Indirect Optimization [PDF]

Journal of Astronomy and Space Sciences, 2015
This work presents fuel-optimal altitude maintenance of Low-Earth-Orbit (LEO) spacecrafts experiencing non-negligible air drag and J2 perturbation.
Kyung-Ha Kim, Chandeok Park, Sang-Young Park   +2 more
doaj   +1 more source

Unscented KALMAN Filtering for Spacecraft Attitude and Rate Determination Using Magnetometer [PDF]

Journal of Astronomy and Space Sciences, 2009
An Unscented Kalman Filter (UKF) for estimation of the attitude and rate of a spacecraft using only magnetometer vector measurement is developed. The attitude dynamics used in the estimation is the nonlinear Euler`s rotational equation which is augmented
Sung-Woo Kim, Mohammad Abdelrabhman, Sang-Young Park, Kyu-Hong Choi   +3 more
doaj   +1 more source

Design of Novel Laser Crosslink Systems Using Nanosatellites in Formation Flying: The VISION

Aerospace, 2022
With growth in data volume from space missions, interest in laser communications has increased, owing to their importance for high-speed data transfer in the commercial and defense fields, spaceborne remote sensing, and surveillance.
Geuk-Nam Kim, Sang-Young Park, Sehyun Seong, Jae-Young Choi, Sang-Kook Han, Young-Eon Kim, Suyong Choi, Joohee Lee, Sungmoon Lee, Han-Gyeol Ryu, Seonghui Kim   +10 more
doaj   +1 more source

Monitoring Terrestrial Water Storage, Drought and Seasonal Changes in Central Oklahoma With Ambient Seismic Noise

Geophysical Research Letters, Volume 50, Issue 17, 16 September 2023., 2023
Abstract Significant imbalances in terrestrial water storage (TWS) and severe drought have been observed around the world as a consequence of climate changes. Improving our ability to monitor TWS and drought is critical for water‐resource management and water‐deficit estimation.
Shuo Zhang, Bingxu Luo, Yehuda Ben‐Zion, David E. Lumley, Hejun Zhu   +4 more
wiley   +1 more source

An Energetic Eruption With Associated SO 1.707 Micron Emissions at Io's Kanehekili Fluctus and a Brightening Event at Loki Patera Observed by JWST

Journal of Geophysical Research: Planets, Volume 128, Issue 8, August 2023., 2023
Abstract We observed Io with the James Webb Space Telescope (JWST) while the satellite was in eclipse, and detected thermal emission from several volcanoes. The data were taken as part of our JWST‐ERS program #1373 on 15 November 2022. Kanehekili Fluctus was exceptionally bright, and Loki Patera had most likely entered a new brightening phase.
Imke de Pater, Emmanuel Lellouch, Darrell F. Strobel, Katherine de Kleer, Thierry Fouchet, Michael H. Wong, Bryan J. Holler, John Stansberry, Patrick M. Fry, Michael E. Brown, Dominique Bockelée‐Morvan, Samantha K. Trumbo, L. N. Fletcher, Matthew M. Hedman, Edward M. Molter, Mark Showalter, Matthew S. Tiscareno, Stéphanie Cazaux, Ricardo Hueso, Statia Luszcz‐Cook, Henrik Melin, Chris Moeckel, Alessandro Mura, Glenn Orton, Lorenz Roth, Joachim Saur, Federico Tosi   +26 more
wiley   +1 more source