near-Earth Space Research Articles

Assessment perspectives for the orbital utilization of space debris

Technogenic pollution of the near-Earth space by fragments of space debris of various sizes significantly limits the possibilities for implementing space activities and represents a great danger to objects on Earth. Low orbits with heights up to 2000 km are particularly heavily clogged. The Inter-Agency Space Debris Coordination Committee recommends removing fragments of space debris from the area of working orbits. Currently, promising ways of space debris removing are considered: descent into the Earth’s atmosphere, relocation to an orbit with a lifetime less than twenty-five years, relocation to an utilization orbit, and orbital disposal. Orbital utilization considers space debris as a resource for the industry in orbit. The objectives of the article are to assess the perspectives for the orbital utilization of space debris and to develop a method for choosing the number and placement of safe recycling orbits in the area of low near-Earth orbits. The paper analyses the prospects for the use of orbital utilization of space debris and the assessment of the possibilities of using orbital storage and subsequent reuse of dismantled space objects, instruments and materials. A number of problems of planning and organizing the orbital utilization of space debris are formulated and solved. A method for determining safe orbits of space debris utilization in the area of low near-Earth orbits based on a criteria system developed. Using the developed method and software package, the possible orbits of space debris utilization in the area of low near-Earth orbits are determined. The lifetime of a space object in the utilization orbit, the stability of the orbit of the utilization at a long time interval, and the energy consumptions for transferring the space object from the working orbit to the utilization orbit are estimated. The novelty of the obtained results consists in the development of a clustering technique for the orbits of utilized space debris objects and the development of a technique for selecting a possible orbit for the utilization of space debris in the area of low near-Earth orbits. The results obtained can be used in the planning and organization of the orbital utilization of space debris.

Five-mode quasilinear model of nonlinear dynamics of extended system

Distributed systems are widely used in practice. These are cosmic ligaments in the near-Earth space with a length of tens of kilometers. They approximate reinforced concrete piles in the soil when calculating the stress-strain state and assessing the technical condition; pipelines both in air and in liquid, underwater towed systems. Known underwater airlift systems of great length for the extraction of minerals (nodules) from the ocean floor with a length of 5-10 km. To solve the problems of the dynamics of such systems in various environments, the well-known mathematical models are not quite correct from the point of view of taking into account the variety of wave processes. It determines the need to build refined wave models. A new quasilinear mathematical model, which describes the nonlinear four-mode dynamics of the distributed system in the spatially inhomogeneous field of mass and surface forces, has been obtained. It is described by a nonlinear system of twelve first-order partial differential equations. For it, the principles of ultimate and hyperbolicity are fulfilled. Together with the boundary and initial conditions, it can be used to describe dynamics and statics of geometrically and physically nonlinear rod elements, piles in the ground, crane equipment ropes, mine lifts, aerial cableways, towed systems in liquid and gas flow, etc. For two-mode spatial reduction of the model, the theorem about correctness of Cauchy problem has been considered. As a result of the calculations, the earlier assumptions about the movement of the cable along its initial configuration were changed as the length of the cable changed. It has been found out that this assumption is only true for the initial transition participant. It is also established that at a given tachogram in the configuration of the towed line, there is a point of inflection, which shifts from top to bottom when lifting it. It can be a factor in the looping, contributing to the breakage of the cable system during towing.

Adaptive observer design for time-varying nonlinear systems with unknown polynomial parameters

The paper considers the construction of optoelectronic systems for monitoring near-Earth space, the choice of algorithms for identifying and obtaining the most reliable coordinate and non-coordinate information about space objects of natural and man-made origin. Experimental mock-up studies using the developed installation were performed. The plant allows the calibration of the optoelectronic system and the study of algorithms for obtaining coordinate and detailed data about the observed objects. The authors apply the method of image registration by a telescopic system in the astrograph with a digital camera mode and a digital camera with a microlens array mode. The work uses the methods for analyzing two-dimensional images by algorithms for measuring binary clusters in an image structure, investigating the brightness structure of an image with a circular boundary in a given area, determining the centers and radii of the circles inscribed in clusters, calculating and estimating the maxima for the curves of the coefficients of continuous wavelet transformation in the image profile lines with real wavelets. The composition and structure of a complex of algorithms and a methodology for their application have been developed. The methodology makes it possible to increase the accuracy and reliability of information obtained about the observed objects in a wide range of changes in the characteristics of the background target environment. The results substantiate the possibility of increasing the accuracy and reliability of coordinate information about the observed objects by analyzing the curves of the coefficients of continuous wavelet transform or analyzing the brightness gradient, provided that the algorithm for analyzing clusters of binarized images is used. The algorithm makes it possible to determine the areas of localization of objects of interest in the observed space. The developed methodology can be applied to assess the accuracy and reliability of the results of determining the coordinates and detailed features of objects. At the same time, it is possible to scale the algorithms to the means of observation and the tasks being solved, which makes it possible to use them in automated monitoring systems for near-earth space and increases the efficiency of detection and identification of objects.

ИСТОРИЯ СОЗДАНИЯ КОРАБЛЯ-СПУТНИКА «ВОСТОК»: ПРОЕКТИРОВАНИЕ И ПРОВЕРКА ИНЖЕНЕРНЫХ РЕШЕНИЙ

The origin of space means of studying the Earth's surface in the 50- 70-s of the twentieth century is inextricably linked with the main stages of the development of space technology. The improvement of methods and technical means for the study of the Earth and near-Earth space took place in the conditions of acute political confrontation between the USSR and the United States. (Research purpose) The research purpose is in identifying the key points that influenced the formation of the “Vostok” satellite program at the design stage from 1957 to 1960, as well as assessing the contribution of engineering and design solutions to the development of the space industry of the Soviet Union. (Materials and methods) The research is based on the materials of the State Archive of the Russian Federation, the Russian State Archive of Scientific and Technical Documentation, the Archive of the President of the Russian Federation, the Russian State Archive of Economics, the Archive of the S. P. Korolev Rocket and Space Corporation “Energiya”, the Archive of the Yuri Gagarin Cosmonaut Training Center, as well as publications of historians, memoirs of witnesses and participants of events, and the results of previous research on this topic. (Results and discussion) The article presents the history of the creation of the program of the Soviet spacecraft- satellites of the “Vostok” series. The greatest difficulty of the project was the development of scientific equipment for scientific research and the transmission of the received data from the satellite to the Earth. The terms of reference for conducting research and developing a control system that ensures the launch of the satellite into orbit were developed; the terms of reference and work plans providing for the research and development of systems and means for getting the results of scientific observations from orbit. (Conclusions) The first flight of the satellite spacecraft showed the correctness of the main theoretical provisions and engineering and design decisions taken when creating an orientable spacecraft.

Investigation of the accuracy of measuring the parameters of remote objects observed by the optical-electronic system with a light field recorder

The paper considers the construction of optoelectronic systems for monitoring near-Earth space, the choice of algorithms for identifying and obtaining the most reliable coordinate and non-coordinate information about space objects of natural and man-made origin. Experimental mock-up studies using the developed installation were performed. The plant allows the calibration of the optoelectronic system and the study of algorithms for obtaining coordinate and detailed data about the observed objects. The authors apply the method of image registration by a telescopic system in the astrograph with a digital camera mode and a digital camera with a microlens array mode. The work uses the methods for analyzing two-dimensional images by algorithms for measuring binary clusters in an image structure, investigating the brightness structure of an image with a circular boundary in a given area, determining the centers and radii of the circles inscribed in clusters, calculating and estimating the maxima for the curves of the coefficients of continuous wavelet transformation in the image profile lines with real wavelets. The composition and structure of a complex of algorithms and a methodology for their application have been developed. The methodology makes it possible to increase the accuracy and reliability of information obtained about the observed objects in a wide range of changes in the characteristics of the background target environment. The results substantiate the possibility of increasing the accuracy and reliability of coordinate information about the observed objects by analyzing the curves of the coefficients of continuous wavelet transform or analyzing the brightness gradient, provided that the algorithm for analyzing clusters of binarized images is used. The algorithm makes it possible to determine the areas of localization of objects of interest in the observed space. The developed methodology can be applied to assess the accuracy and reliability of the results of determining the coordinates and detailed features of objects. At the same time, it is possible to scale the algorithms to the means of observation and the tasks being solved, which makes it possible to use them in automated monitoring systems for near-earth space and increases the efficiency of detection and identification of objects.

Cosmic meteorology

Abstract Mike Lockwood and Mat Owens discuss how eclipse observations are aiding the development of a climatology of near-Earth space

PROGRESS OF THREE-BODY ORBITAL DYNAMICS STUDY

The orbital dynamics in the three-body system is a classical problem in the field of astrodynamics. It has rich theoretical and engineering significance, and have played an important role in the process of space activities extending from near-earth space to deep space. This paper reviews and summarizes the progress of the study of orbital dynamics in the three-body system. Combined with the development trend of deep space exploration in the future, the hotspots and challenges in the research of three-body orbital dynamics are prospected. First, the research background and significance of the three-body problem are surveyed, and the development of the dynamics model of the three-body system is briefly reviewed. Secondly, characteristics of the local motion near the equilibrium point in the three-body problem are systematically summarized. The analytical and numerical methods for periodic orbits are introduced. The latest development of quasi-periodic motion is discussed. Meanwhile, the characteristics and research progress of global periodic motions in the three-body system including resonance orbits, cycler trajectories, and free return orbits are summarized. Next, the research progress of the low-energy transfer and capture trajectory design in the three-body system is analyzed from two aspects of invariant manifold theory and weak stability boundary theory. Finally, the applications of orbital dynamics in the three-body system in formation flight and navigation constellation design are summarized. Several orbital dynamics and control problems in the design of landing trajectories for full lunar-surface coverage, the low thrust orbit optimization of the three-body system, and the utilization of non-linear equilibrium points in the three-body system are addressed for future study.

The Main Asteroid Belt: The Primary Source of Debris on Comet-like Orbits

Abstract Jupiter-family comets (JFCs) contribute a significant amount of debris to near-Earth space. However, telescopic observations of these objects seem to suggest that they have short physical lifetimes. If this is true, the material generated will also be short-lived, but fireball observation networks still detect material on cometary orbits. This study examines centimeter-to-meter-scale sporadic meteoroids detected by the Desert Fireball Network from 2014 to 2020 originating from JFC-like orbits. Analyzing each event’s dynamic history and physical characteristics, we confidently determined whether they originated from the main asteroid belt or the trans-Neptunian region. Our results indicate that <4% of sporadic meteoroids on JFC-like orbits are genetically cometary. This observation is statistically significant and shows that cometary material is too friable to survive in near-Earth space. Even when considering shower contributions, meteoroids on JFC-like orbits are primarily from the main belt. Thus, the presence of genuine cometary meteorites in terrestrial collections is highly unlikely.

Analysis of the Informativity of the Earth’s Magnetic Field in Near-Earth Space

Analysis of the Informativity of the Earth’s Magnetic Field in Near-Earth Space

Secular Resonances in the Dynamics of Objects Moving in LEO–MEO Regions of Near-Earth Orbital Space

Secular Resonances in the Dynamics of Objects Moving in LEO–MEO Regions of Near-Earth Orbital Space

Key issues of modernization of space governance

Space is the fourth domain of human activities after land, sea and air. After 60 years of development, the number of China’s in-orbit spacecraft has ranked the second in the world. The scope of space activities is extending from near-Earth space to the moon, asteroids, Mars and other deep space objects. Commercial space industry grows vigorously. The governance of space activities is the management and regulation of various activities of entering, exploring, developing and utilizing space, including organization management, laws and regulations, international governance, technical support, etc. The governance modernization of space activities is the strategic pivot in modernization of national governance. It serves as means for nations that participate in global governance, and is also the prerequisite for becoming one of the leading nations in space domain. The governance system of space activities incorporates four aspects: Regime, protocol, global coordination, and technical means. The governance modernization of space activities is to reform the system and mechanism barriers, laws and regulations, and technical thresholds that are not suitable for present development, and to expedite its systematization, regularization, legalization, scientization. In this paper, the newest situation in the current space governance is analyzed from four perspectives, including the increasingly severe space security situation, the fierce competition for space resources, the increasing competition for international space dominance, and the necessity to improve the technical capabilities of space governance. On this basis, the development status of space governance in China is presented from four aspects, including the organization and management, laws and regulations, international cooperation, and pertinent technologies. Subsequently the three issues of space activities governance capabilities and modernization requirements are analyzed, including insufficient space resource coordination, inadequate space governance capabilities, and weak dominance of international dialogue. In respect of the above aspects, this paper proposes to strengthen the role of space activity governance in the national governance, to establish a mechanism for conducting research on the normalization of space activity governance, to promote the process of legislation related to space governance, to increase policy support and investment in international cooperation, and to carry out a series of measures such as strengthening the guidance and supervision of commercial space activities. In terms of organization and management, it is necessary to focus on the research of organizational optimization, efficient operation mechanisms, and organization and management effectiveness evaluation. In terms of laws and regulations, it is necessary to focus on the framework of the legal and regulatory system, the formulation of key laws and regulations, and the efficient implementation mechanism of laws and regulations. In terms of international cooperation, it is necessary to focus on the research of long-term sustainable international cooperation goals and policies, international rules based on the concept of a community with a shared future for mankind, and major projects to facilitate international cooperation. In terms of technical support systems, it is necessary to focus on space object monitoring, space data application, space spectrum monitoring, space debris mitigation, space facility maintenance, near-Earth object defense and other technical research of space activities in the governance support technology system. The methods mentioned above will accelerate the modernization of China’s governance system and capability of space activities and lay a solid foundation for becoming a space power.

Principles of forming procedures for justifying the economic efficiency of space debris removal processes

Near-Earth space pollution can be classified as an international problem. The research considers variation technical and technological innovative projects that can decide this problem, as well as methods for calculating the costs of their realization. Cost and labor intensity modeling takes into account the concept of designing systems for the disposal of cataloged space debris. Unitized approaches to technical and economic assessment of the feasibility of space debris disposal concepts are considered and a mechanism for justifying economic efficiency is developed, which includes the following synergistic differentiated principles: the objectivity and subjectivity, the accuracy and reliability increasing, the marginal cost estimation, the probabilistic risk assessment accounting, the principle of logical-probabilistic modeling of development obsolescence in outer space, the principle of risk assessment and monitoring of space projects. The proposed mechanism for evaluating the economic efficiency based on additive factors can be used for economic justification of scientific, technical and experimental-design developments of space vehicles for technological designated purpose.

Design of X-band SSPA based on GaN HEMT for telemetry subsystem of near-earth space missions

In this paper, the design, and implementation of an X-band, 10 W, Solid-State Power Amplifier (SSPA) based on Hybrid Microwave Integrated Circuit (HMIC) technology using Gallium Nitride (GaN) High-Electron Mobility Transistor (HEMT) dies for near-earth space applications is presented. Designed SSPA is customized for use in suborbital missions and has two stages. We have used narrowband Transmission Lines (TL) class E architecture for designing the proposed SSPA. We have applied the transconductance tuning technique for the first time to a GaN HMIC for achieving the required linearity without any additional circuits. Hybrid optimization helps us for obtaining the best output power, efficiency, and linearity in comparison to other X-band GaN HMICs. We implemented our design with a Rogers 6010 laminate printed circuit board (PCB) on a Cu plate for improving the thermal heat transfer. All the on-chip pads were bonded to PCB using gold bonding wires with 25-µm diameter directly. We obtained 40 dBm and 37 dBm maximum output power in the saturation and 1-dB compression point, respectively. The central frequency of the proposed SSPA is 10,640 MHz with 150 MHz Band Width (BW). It works in EB-class with a 40 V voltage power supply and has more than 40% efficiency in saturation output power (Psat). We obtained two tones Intermodulation Distortion Third Harmonic (IMD3) better than −17 dBc in-band. The active area of the implemented SSPA is 40 mm × 50 mm.

Calculating a Directional Flux in Near-Earth Space

Calculating a Directional Flux in Near-Earth Space

Study of the kinetics of gas evolution of a polymer composite under the influence of vacuum and VUV

The paper presents data on the effect of high vacuum and vacuum ultraviolet (VUV) on a polymer composite based on polyimide track membranes. Polyimide track membranes were filled with POSS structures. For comparison, we also used pure polyimide films without filler. Exposure in high vacuum and surface treatment of the developed VUV composite were carried out in the imitation chamber of near-Earth space, located in the Space Materials Science Laboratory of BSTU named after V.G. Shukhov (Russia, Belgorod). The high resistance of the composite to high vacuum and VUV has been established. The total weight loss of the composite by 24 hours was 0.26 wt. % (after holding in vacuum) and 0.28 wt. % (after VUV).

An analytical model of zenith radiance under different atmosphere and earth-surface conditions for JHKs bands

The application of star sensor navigation to aircraft and ships is a significant development direction. Due to the intense sky background radiation in the daytime, it is difficult for a visible-light camera to detect stars effectively in near-earth space, the development of a short-wavelength infrared (SWIR, especial for JHKs bands) detector provides the possibility for it. However, in the system design, simulation verification, and software integration of star sensor based on SWIR, a mass of sky background data of JHKs bands under different atmosphere and earth-surface conditions is needed as input. Although the existing atmospheric radiative transfer software can generate large amounts of discrete sky background data in some directions, it has a complicated operation, low efficiency, and time-consuming disadvantage, which is challenging to meet the real-time application in engineering. To use the sky background radiation data more efficiently and conveniently, an analytical model of zenith radiance for JHKs bands is urgent to build. Zenith radiance reference data are generated by libRadtran. Atmospheric absorption function and atmospheric scattering function are used to construct the analytical model of zenith radiance. The Levenberg-Marquardt (L-M) method is used to solve the parameters of the analytical model of zenith radiance. The Adaptive Moment Estimation (Adam) method is used to optimize the parameters of the analytical model of zenith radiance. The mean relative error between the zenith radiance's analytical function value and the zenith radiance's reference data is calculated to evaluate the accuracy of the constructed analytical model of zenith radiance. The results show that the mean relative errors are no greater than 2.54%, 2.15%, 2.26%; the root mean square errors are no greater than 1.0414, 0.2462, 0.0642; the correlation coefficients are no less than 0.9985, 0.9976, 0.9979 for all combination of cases corresponding to JHKs bands. It indicates that zenith radiance's analytical model constructed is exact and can provide a useful reference for the star sensor's demonstration design and application assessment based on SWIR technology.

Complexity measures of geomagnetic indices in the last two solar cycles

The SYM-H and AE geomagnetic indices can be considered as proxies of the response of the Earth’s magnetosphere and ionosphere to solar magnetic activity. They indirectly monitor some electric current systems which flow in the ionosphere and magnetosphere whose dynamics are directly or indirectly related to the Sun–Earth interaction. Consequently, their temporal changes reflect processes occurring in the near-Earth space, which contribute differently to the overall magnetosphere–ionosphere dynamics. The aim of this work is to characterize the nature of these two geomagnetic indices by following a complex system approach and applying a novel formalism, e.g., the EMD-based dominant amplitude multifractal formalism (EMD-DAMF). A set of complexity measures, i.e., the Hurst exponent (H), the singularity width (Δα) and the spectrum width (Δf), is evaluated for both geomagnetic indices analyzing data recorded during the last two solar cycles. One of the most significant findings of this study is the absence of relevant differences between the two solar cycles in terms of complexity measures for both geomagnetic indices, suggesting that only the occurrence and the frequency of geomagnetic storms and substorms affect the Hurst exponent and the singularity widths of SYM-H and AE indices. Moreover, while the AE index complexity measures do not show a significant dependence on geomagnetic activity, the SYM-H index shows a reduction in its complexity features during the geomagnetic storms, manifesting a more persistent behavior and moving from a (mono)fractal-like to a multifractal-like behavior when passing from quiet to disturbed periods. Finally, our findings are consistent with previous works on the forecast horizon of the geomagnetic activity as well as on the relation between the high-latitude ionosphere and the low-latitude magnetosphere, thus confirming the importance of providing higher resolution measures for correctly dealing with several Space Weather phenomena.

NEOExchange - an online portal for NEO and Solar System science

Las Cumbres Observatory (LCO) has deployed a homogeneous telescope network of ten 1-m telescopes to four locations in the northern and southern hemispheres, with a planned network size of twelve 1-m telescopes at 6 locations. This network is very versatile and is designed to respond rapidly to target of opportunity events and also to perform long term monitoring of slowly changing astronomical phenomena. The global coverage, available telescope apertures, and flexibility of the LCO network make it ideal for discovery, follow-up, and characterization of Solar System objects such as asteroids, Kuiper Belt Objects, comets, and especially Near-Earth Objects (NEOs).We describe the development of the “LCO NEO Follow-up Network” which makes use of the LCO network of robotic telescopes and an online, cloud-based web portal, NEOexchange, to perform photometric characterization and spectroscopic classification of NEOs and follow-up astrometry for both confirmed NEOs and unconfirmed NEO candidates.The follow-up astrometric, photometric, and spectroscopic characterization efforts are focused on those NEO targets that are due to be observed by the planetary radar facilities and those on the Near-Earth Object Human Space Flight Accessible Targets Study (NHATS) lists. Our astrometric observations allow us to improve target orbits, making radar observations possible for objects with a short arc or large orbital uncertainty, which could be greater than the radar beam width. Astrometric measurements also allow for the detection and measurement of the Yarkovsky effect on NEOs. The photometric and spectroscopic data allows us to determine the light curve shape and amplitude, measure rotation periods, determine the taxonomic classification, and improve the overall characterization of these targets. We are also using a small amount of the LCO NEO Follow-up Network time to confirm newly detected NEO candidates produced by the major sky surveys such as ATLAS, Catalina Sky Survey (CSS) and PanSTARRS (PS1). We will describe the construction of the NEOexchange NEO follow-up portal and the development and deployment methodology adopted which allows the software to be packaged and deployed anywhere, including in off-site cloud services. This allows professionals, amateurs, and citizen scientists to plan, schedule and analyze NEO imaging and spectroscopy data using the LCO network and acts as a coordination hub for the NEO follow-up efforts. We illustrate the capabilities of NEOexchange and the LCO NEO Follow-up Network with examples of first period determinations for radar-targeted NEOs and its use to plan and execute multi-site photometric and spectroscopic observations of (66391) 1999 KW4, the subject of the most recent planetary defense exercise campaign.

Development of the Common Classification of Hazard Events in Near-Earth Space

The article summarizes the practical experience of performing work to prevent hazard events in the near-Earth space (NES), including the mathematical formulation of the problem of calculating the collision probability, work on detecting potentially hazardous asteroids, and general principles for detecting potentially hazardous conjunction of space objects. Approaches to the formation of the common classification of hazard events in NES are considered. A description of the components of the classification system in the form of separate units is presented.

The AURA Atmosphere Radiation Detector Based on Silicon Photomultipliers for Small Spacecrafts of the Cubesat Type

The SINP MSU is implementing a program to create compact detectors for studying the atmosphere and near-Earth space from small spacecrafts of the Cubesat type. Within the framework of this program, the AURA detector of ultraviolet radiation of the Earth’s atmosphere described in this article has been developed and tested. The device is a four-channel photometer based on silicon photomultiplier from the SensL Co. Its compactness, low supply voltage, and durability are the factors that determine the advantages for its use in nanosatellites.