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1984년 ~ 2025년까지 1,251 건의 한국우주과학회지를 계간으로 확인하실 수 있습니다.
- The Korean Space Science Society (The Korean Astronomical Society)
- 계간 (Quarterly)
- ISSN : 1225-052x (ISSN : 1225-052x)
1225-052x
- DB구축현황 : 1,251건 (DB Construction : 1,251 Articles)
총 게시글 1,251건
페이지 1/126
1
- Myunghwan Kim
- Journal of astronomy and space sciences
- 42, n.1
- pp.29-37
- 2025
- 원문 바로보기
This study examined the variations of solar, interplanetary, and geomagnetic (SIG) parameters from 1974 to 2024 to assess the changes in the solar cycle. Eleven SIG parameters were analyzed, including the sunspot number (SSN), solar magnetic field, 10.7 cm solar radio flux, total solar irradiance, and Ap index. This study also aimed to predict Solar Cycle 25 using the seasonal autoregressive integrated moving average (SARIMA) statistical forecasting model. The results showed that consistent with previous studies, all SIG parameters exhibited a strong correlation with the SSN. The change in SSN strongly influences the variations in all SIG parameters, even though some exhibit time-lagged responses. The cross-correlation analysis revealed a high correlation coefficient of 0.9678 between the SSN and the 10.7 cm solar radio flux without delay. Most SIG parameters showed a general weakening trend toward Solar Cycles 22-24. This suggests that solar activity is waning over time. In particular, the solar polar magnetic field (SPMF) showed a large decrease in the solar minimum 23/24, and specifically, the SPMF at the south pole weakened more rapidly than at the north pole. Hence, the SPMF is changing asymmetrically between the north and south poles. This weakening of the solar magnetic field suggests an increase in galactic cosmic rays within the heliosphere, exposing the Earth to higher levels of cosmic rays. Finally, forecasts for Solar Cycle 25 using the SARIMA model predict that the SSN will continue to decline after the solar maximum in 2024, with the predicted minimum SSN of 9.42 in October 2028, and will likely enter a solar minimum period around 2030.
2
- Back, Junho
- Journal of astronomy and space sciences
- 42, n.2
- pp.39-46
- 2025
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<P> The electron density profiles produced from the ionospheric sounding system are traditionally estimated by the inversion procedure based on the image analysis of the observed ionograms. Jang Bogo Vertical Incidence Pulsed Ionospheric Radar (VIPIR) with Dynasonde (hereafter, JVD), however, uses the three-dimensional electron density inversion approach named “NeXtYZ” to produce ionospheric density, ion velocity, and tilt of the ionization in the bottomside ionosphere based on the list of detected radio echoes with their physical parameters. Sometimes, the resulting density profiles can be erroneous, not reflecting real ionosphere, probably due to severely disturbed ionosphere in the polar region. In this study, the automatic classification procedure of the estimated electron density profiles is developed to filter out unusable data for the 5-year period from 2017 to 2021. The ionograms are classified into four categories: ‘Unavailable’, ‘Sporadic E’, ‘Needs Reprocessing’, and ‘Available’. It is found that approximately 50% of ionograms are evaluated to be reasonable with proper electron density profiles and about 35% of them tend to be affected by sporadic-E like structures, blocking the F-region ionosphere to be observed. It should be noted that the sporadic-E like structures in the polar ionosphere seems to be main obstacles for the ionospheric sounding observation of the F-region ionosphere. Only less than 10% of ionograms are classified as a reprocessing type which needs to be reprocessed. Finally, no echoes are recognized by Dynasonde analysis for about 5% of ionograms. The reprocessing and/or unavailable types might be associated with auroral precipitations that disturbs the ionosphere in the polar region. </P>
3
- Kim, Ji Eun
- Journal of astronomy and space sciences
- 42, n.2
- pp.47-61
- 2025
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<P> The tip of the Antarctic Peninsula is widely recognized as one of the most active regions for gravity wave activity. Situated in this dynamic area, the King Sejong Station (KSS: 62.22°S, 58.78°W) serves as an ideal location for investigating gravity wave activity in the mesosphere and lower thermosphere (MLT) region. The Korea Polar Research Institute (KOPRI) has been operating a meteor radar (MR) and an airglow all-sky camera (ASC) at KSS for over a decade, enabling studies on gravity wave activity and MLT dynamics. To enhance these observational capabilities, a new optical instrument, the Advanced Mesospheric Temperature Mapper (AMTM), was installed in January 2023. The KSS-AMTM provides hydroxyl (OH) airglow intensities at approximately 87 km altitude as well as two-dimensional temperature maps at a high temporal resolution. This study presents a brief overview of the observational features and operation of the instrument, alongside initial results obtained over 28 clear nights from February to October 2023. As part of the initial validation, observed mesopause temperatures were compared with data from meteor radar and the Microwave Limb Sounder onboard the Aura satellite. </P>
4
- Sheer Abbas
- Journal of astronomy and space sciences
- 42, n.1
- pp.1-13
- 2025
- 원문 바로보기
The advent of low Earth orbit (LEO) mega satellite constellations to accelerate high-speed internet worldwide represents a new technological advancement. However, this development raises concerns regarding militarization, orbital debris, environmental protection, and their effects on space tourism. Despite these challenges, existing space law treaties have not addressed these issues. This article highlights the gaps in current treaties and emphasizes the need for advancements to mitigate emerging challenges and ensure long-term solutions. This study explores the legal challenges associated with possible smashes flanked by existing satellites in orbit and newly launched satellites as part of mega-constellations, which could jeopardize mission safety and threaten the sustainability of space activities. It also analyzes the significant issues related to space debris, particularly given the anticipated increase in satellite constellations in LEO over the coming decades. The increase in small satellites with shorter lifespans is likely to contribute to greater debris generation. Finally, these findings suggest the need for a suitable international legal structure to facilitate the efficient deployment and operation of satellite techniques.
5
- Juhyeong Kim
- Journal of astronomy and space sciences
- 42, n.1
- pp.15-27
- 2025
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The mission-assisting anisotropic magnetoresistive sensor (MAMS) module is one of the components supporting the operation of the lunar surface magnetometer (LSMAG), one of the Korean candidate payloads for the Commercial Lunar Payload Services (CLPS) program. LSMAG uses fluxgate magnetometers (FGMs), which have a 0.2 nT resolution and ± 2,000 nT measurement range. For the scientific analysis of LSMAG data, four types of additional mission-assisting functions are required: strong magnetic field measurement, lander noise detection, offset calibration signal generation, and attitude information provision. To perform these functions, the MAMS module utilizes anisotropic magnetoresistive (AMR) sensors (HMC1001/1002), an accelerometer (ADXL355), and an artificial magnetic field generating circuit. The AMR sensors have a larger measurement range than FGMs. Therefore, these sensors are suitable for measuring strong magnetic fields and the lander's noise signal, making them applicable for noise-removal techniques. The MAMS module also includes an accelerometer (ADXL355) to measure the attitude of the LSMAG boom and features an artificial field-generating function to determine the sensor offset. The MAMS module passed functional and space environmental tests to verify its performance. The AMR sensors have a 20 nT resolution and ± 80,000 nT range, while the accelerometer has a 6 mg resolution and ± 2 g range under Earth conditions. This module includes its own microcontroller unit and supports a wide input voltage range and standard RS485 universal asynchronous receiver/transmitter (UART) communication. We expect the MAMS module to not only play an essential role in supporting LSMAG data calibration and operation, but also to be used in various future space science exploration missions.
6
- Moon-Jin Jeon
- Journal of astronomy and space sciences
- 41, n.1
- pp.43-60
- 2024
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Korea Pathfinder Lunar Orbiter (KPLO) is South Korea's first space exploration mission, developed by the Korea Aerospace Research Institute. It aims to develop technologies for lunar exploration, explore lunar science, and test new technologies. KPLO was launched on August 5, 2022, by a Falcon-9 launch vehicle from cape canaveral space force station (CCSFS) in the United States and placed on a ballistic lunar transfer (BLT) trajectory. A total of four trajectory correction maneuvers were performed during the approximately 4.5-month trans-lunar cruise phase to reach the Moon. Starting with the first lunar orbit insertion (LOI) maneuver on December 16, the spacecraft performed a total of three maneuvers before arriving at the lunar mission orbit, at an altitude of 100 kilometers, on December 27, 2022. After entering lunar orbit, the commissioning phase validated the operation of the mission mode, in which the payload is oriented toward the center of the Moon. After completing about one month of commissioning, normal mission operations began, and each payload successfully performed its planned mission. All of the spacecraft operations that KPLO performs from launch to normal operations were designed through the system operations design process. This includes operations that are automatically initiated post-separation from the launch vehicle, as well as those in lunar transfer orbit and lunar mission orbit. Key operational procedures such as the spacecraft's initial checkout, trajectory correction maneuvers, LOI, and commissioning were developed during the early operation preparation phase. These procedures were executed effectively during both the early and normal operation phases. The successful execution of these operations confirms the robust verification of the system operation.
7
- Shinhye Moon
- Journal of astronomy and space sciences
- 41, n.2
- pp.61-78
- 2024
- 원문 바로보기
This study developed a real-time spacecraft pose estimation algorithm that combined a deep learning model and the least-squares method. Pose estimation in space is crucial for automatic rendezvous docking and inter-spacecraft communication. Owing to the difficulty in training deep learning models in space, we showed that actual experimental results could be predicted through software simulations on the ground. We integrated deep learning with nonlinear least squares (NLS) to predict the pose from a single spacecraft image in real time. We constructed a virtual environment capable of mass-producing synthetic images to train a deep learning model. This study proposed a method for training a deep learning model using pure synthetic images. Further, a visual-based real-time estimation system suitable for use in a flight testbed was constructed. Consequently, it was verified that the hardware experimental results could be predicted from software simulations with the same environment and relative distance. This study showed that a deep learning model trained using only synthetic images can be sufficiently applied to real images. Thus, this study proposed a real-time pose estimation software for automatic docking and demonstrated that the method constructed with only synthetic data was applicable in space.
8
- Sheer Abbas
- Journal of astronomy and space sciences
- 41, n.4
- pp.235-247
- 2024
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The advent of 'space tourism' has induced outer space law to respond and adapt to this dramatic growth because of the principled contribution of private entities in these activities. This article discusses the main legal aspects of licensing, supervision, liability, registration, and health side effects, and how these reveal the influence of space tourism. Because of the moral participation of private individuals in these activities, 'space tourism' demands that outer space law be modified and adaptable. Although many issues of ship, crew, and passenger certification have not been defined in international law, these would be evaluated to show that domestic legislative interests may drive the law before it reaches international law. Air and adventure tourism laws are also evaluated. Space are not likely to remain limited to professionally trained individuals and wealthy astronauts. The potential for public access to space raises complex legal, health-related, and ethical questions on the inadequacy of the current international legal instruments addressing the utilization and exploration of outer space. Furthermore, this study is designed to evaluate the role of human presence in spaceflights, accidents that occurred to participants of space missions, and other risks spaceflights may induce on humans. In addition, this study focuses on analyzing existing legal regulations related to astronauts' health and life protection during spaceflight and how states can address emerging challenges to astronauts' safety. The existing global legal framework regulating aviation and space operations is unsuitable for the widespread commercial entry into space. This is because it was designed when drafters did not envisage such endeavors to this extent. The insufficient legal clarity should be addressed rapidly to set applicable standards to promote such activities. To conclude, this article compares national space regulations and elaborates on the drawbacks of the current international space regulations.
9
- Nurzhan Ussipov
- Journal of astronomy and space sciences
- 41, n.3
- pp.149-158
- 2024
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This study developed a machine learning-based methodology to classify gravitational wave (GW) signals from black hol-eneutron star (BH-NS) mergers by combining convolutional neural network (CNN) with conditional information for feature extraction. The model was trained and validated on a dataset of simulated GW signals injected to Gaussian noise to mimic real world signals. We considered all three types of merger: binary black hole (BBH), binary neutron star (BNS) and neutron starblack hole (NSBH). We achieved up to 96% correct classification of GW signals sources. Incorporating our novel conditional information approach improved classification accuracy by 10% compared to standard time series training. Additionally, to show the effectiveness of our method, we tested the model with real GW data from the Gravitational Wave Transient Catalog (GWTC-3) and successfully classified ~90% of signals. These results are an important step towards low-latency real-time GW detection.
10
- Ulkar Karimova
- Journal of astronomy and space sciences
- 41, n.1
- pp.35-42
- 2024
- 원문 바로보기
Sungrazing comets, known for their proximity to the Sun, are traditionally classified into broad groups like Kreutz, Marsden, Kracht, Meyer, and non-group comets. While existing methods successfully categorize these groups, finer distinctions within the Kreutz subgroup remain a challenge. In this study, we introduce an automated classification technique using the densitybased spatial clustering of applications with noise (DBSCAN) algorithm to categorize sungrazing comets. Our method extends traditional classifications by finely categorizing the Kreutz subgroup into four distinct subgroups based on a comprehensive range of orbital parameters, providing critical insights into the origins and dynamics of these comets. Corroborative analyses validate the accuracy and effectiveness of our method, offering a more efficient framework for understanding the categorization of sungrazing comets.