The experience of JSC “Russian Space Systems” in the development of on-board equipment for command radio links of spacecraft for various purposes with a given level of radiation resistance under conditions of long-term exposure to ionizing radiation of outer space for the period from 2003 to 2021 is summarized. The main stages of work to ensure the resistance of onboard equipment to integral dose effects and the effects of single events are considered. Methodological and software resources have been developed that allow correct prediction of local dose loads of ionizing radiation from outer space in the on-board equipment of command radio links, taking into account the effect of “dose amplification” of secondary bremsstrahlung. The methodological issues of ensuring the terms of the active existence of the onboard equipment are considered, using the cold redundancy of critical devices and components. The use of cold redundancy makes it possible to increase the duration of active existence relative to resistance to integral dose effects by about 1.5 times. The effectiveness of the developed methodological and software resources for confirming the radiation resistance of the onboard equipment of command radio links is proved by successful operation of about 100 spacecraft for various purposes in the 2005–2021 period.
The paper presents an approach to the synthesis of a transceiving feed for axisymmetric double reflector antennas based on the aperture separation of C- and Ka-band signals of coaxial and circular waveguides with a maximum separation of the extreme bands of 10 : 1. The development and selection of a coaxial feed design for constructing a feed system of the transceiving reflector antenna was carried out. Optimal parameters of the coaxial feed were determined and experimentally proved to provide a feed angle level of the subreflector of 30◦ and a VSWR of 1.25 for the C- and Ka-band outputs in the receiving channels and 1.15 and 1.3 for the C- and Ka-band transmission channels, respectively, with the bandwidth of Сreception — 21 %, Сtransmission — 18.2 %, Каreception — 8.6 %, Каtransmission — 7.8 %. The results of practical implementation are presented.
Creating an integrated system of orientation and navigation of small spacecraft based on precision sensors of inertial and external information is an urgent task for the space industry. The object of research is a micromechanical gyroscope (MMG) with a gimbal suspension of a sensitive element. The problem of increasing the accuracy of the MMG by building a new mathematical model of the sensor accurate enough to take into account the influence of technological errors of manufacturing and nonlinear nonstationary effects associated with finite oscillations of a sensitive element and slow change in system parameters. To build a digital model of the micromechanical inertial information sensor, parametric design systems have been applied enabling a full cycle of design documentation creation and calculations. The parametric calculations of the structural scheme were used to analyze the stress-strain state of mechanical elements under various external influences including extreme overloads. The obtained mathematical model was supplemented by analytical methods of nonlinear mechanics, which allow taking into account the influence of finite vibrations of structural elements on the dynamics and accuracy of measurements of angular motion of the gyroscope base. The results of bench experimental tests of sensors carried out to check the adequacy of the developed numerical mathematical model are discussed.
In the article, arrays of two and three microstrip emitters of elliptical polarization are studied by the methods of electrodynamic analysis. Formulas are obtained for determining the corrections to the amplitudes and phases of the array elements, which ensure the presence of dips in the resulting radiation pattern. The dependence of the width of the dip near zero of the radiation pattern on the number of elements in the array, its pitch, and design has been studied. It is shown that at a fixed dip depth exceeding minus 100 dB, its width slightly depends on the array type and dip orientation in the upper or lower hemisphere of the diagram. At the same time, at different depths of the dip, its width can vary significantly and depends on the accuracy of compliance with the amplitude-phase relationships that provide zeros of the radiation pattern.
This article presents a brief description of the life of one of our legendary contemporaries, who sat at the control panel of the device that communicated between two great people who initiated the era of cosmonautics, S. P. Korolyov and Yu. A. Gagarin, during the first manned flight into space. L. I. Gusev was the liaison between the General Designer and the first cosmonaut of the Earth during this epoch-making event. Today it is already obvious to everyone that without its complexes of radio engineering, telemetric and trajectory measurements, it would be impossible to explore outer space. Enterprises and organizations led by L. I. Gusev, took an active part in all key events in the Russian space industry — from the launch of the First artificial Earth satellite to the development, creation and operation of modern space complexes and systems in all areas of space activity.
The article examines the concepts of resolving power and spatial resolution (linear, limiting, diffraction) in analog (photographic) and digital (optoelectronic) aerospace ERS systems. It was found that the foreign criterion for assessing the limiting geometric resolution of the remote sensing system of remote sensing on the terrain, the GSD criterion, is inadequate for assessing the linear spatial resolution. Its use in the design of the remote sensing system impedes the matching of the lens and the digital detector according to the Nyquist criterion. This leads to information and financial losses. It is shown that the GSD criterion characterizes the minimum size of an object perceived by the remote sensing system on the earth’s surface, and not the minimum distance between two separately observed (resolvable) objects, that is, the concept of “limiting resolution” is closer to the concept of “sharpness” of the image, and not to the concepts of “resolution” and “spatial resolution”, and therefore cannot be used to assess the spatial resolution and design of the remote sensing system. It was found that to assess the quality and design of ERS systems, it is necessary to use the Russian criterion for assessing the instrumental linear spatial resolution of ERS systems on the terrain, the RSS criterion, which gives a real assessment of the spatial resolution, allows the projected ERS systems to be matched according to the Nyquist criterion with a design excellence factor equal to one (K = 1), and provides the ability to achieve the diffraction limit of the linear spatial resolution of the ERS systems on the terrain. In order to avoid further erroneous use of the foreign GSD criterion in the Russian Federation, it is proposed to standardize the domestic RSS criterion with the Russian GOST and use it to assess the quality and design of remote sensing systems.
It is shown that a necessary condition for effective management of the process of evolution of information and telemetric support (ITS) for the development of various objects of rocket and space technology is its regulation. The essence of regulation is not obvious due to the variety of objects, ITS tools, ITS tasks, conditions for solving these problems. Therefore, for its implementation, it is advisable to structure ITS means, i.e. grouping of individual means according to systems of information-telemetric support for the development of certain objects (SITS). The proposed approach to the structuring of ITS tools makes it possible to determine the directions of development of individual elements (individual ITS tools) as part of the ITS, moreover, proceeding from the set of analyzed alternative strategies for the improvement and application of these ITS, evaluating these strategies using the developed complex of universal (generalized) indicators based on the theory of evaluating the efficiency of operations using technical systems. For a separate SITS, its official development concept (indicating promising development directions) and the telemetry standards system based on its provisions are relevant. The most favorable conditions for solving the regulation problem are associated with the system of information-telemetric support for the development of launch vehicles (SITSLV).
The hydrometeorological spacecraft Arktika-M No. 1 was successfully launched in February 2021. The Arktika-M series spacecraft are used in the highly elliptical orbit Molniya, which allows regular imaging of the Earth’s polar regions that are inaccessible for observation from the geostationary orbit. Information from these satellites is applied to solve problems of operational meteorology, hydrology, climate, and environmental monitoring in the Arctic region. The MSU-GS/VE equipment deployed on these spacecraft is slated for receiving images of the Earth in the visible and infrared ranges of the electromagnetic spectrum with the periodicity of up to 15 minutes. The MSU-GS/VE equipment is the analogue of the MSU-GS equipment developed for geostationary spacecraft and upgraded for use in imaging from a highly elliptical orbit. The paper presents the first results of the MSU-GS/VE equipment operation. Modernization of the MSU-GS equipment, which allows using it on the Arktika-M series spacecraft, is described. Further development of the MSU-GS and MSU-GS/VE equipment is also discussed.
Determining the GLONASS signal threat space is necessary for the operation of the signal quality monitor, which is a part of the station that generates differential corrections for these signals. To account for the threat effects on the signal, known as the Evil Waveform (EWF), a model recommended by ICAO is used. The thresholds for the EWF detection are determined according to the established limiting errors of differential measurements. The measuring path of the navigation receiver of the station is represented by a serial connection of a pre-correlation filter, including an antenna, and a tracking loop correlator, the discriminator of which is used to estimate the EWF error. Four types of filters with their numerical parameters and several values of the discrimination S-curve width are considered, which made it possible to obtain the results of the EWF impact for 84 variants of the path configuration for each signal. The maximum range of change in the values ??of the model parameters among all options, when the error exceeded the threshold, determined the desired threat space for each signal. It is concluded that the wider the signal spectrum, the smaller is its threat space. The presented way of determining the threat space is applicable to other signals of navigation systems.
The accuracy of the formation of sounding signals of quasi-continuous radars is determined by the requirements for the permissible instrumental component of the error in measuring of the distance and Doppler frequency shift. High-precision orbital radio altimeters, as a rule, use precision signals with linear frequency modulation (chirp signals) as sounding signals, the linearity characteristics of which are quite demanding, since deviations from the linear law of change in the frequency of the radio altimeter sounding signal cause additional measurement errors. To reduce the instrumental error of the radio altimeter, it is necessary to improve the quality of the formation of the probing chirp signal, which can be ensured by forming them digitally. To assess the possibility of using a synthesizer based on the 1508PL8T microcircuit as a generator of the probing signal of a radio altimeter, measurements of the frequency modulation linearity were performed. The linearity of the modulation was estimated by the deviation of the instantaneous phase of the synthesized signal from the quadratic dependence. Studies have shown that fast fluctuations of the chirp signal frequency are significantly influenced by the time it takes the synthesizer to change the rate of rise of the signal phase. The selection of the parameters of the synthesized signals and the characteristics of the filters at the output of the digital-to-analog converters made it possible to reduce the formation error to 2.9·10−3 rad (RMS). When choosing the type of integrated synthesizer, it is necessary to focus on microcircuits with a high DAC clock frequency (above 1 GHz) and a short time spent on changing the output signal frequency (no more than 4 clock periods).
A method of shielding the elements of a microwave module based on the principles of forming a Faraday cage, with different power and different frequency paths of the AFAR receiving-transmitting module, excluding their mutual electromagnetic influence, is presented. A description of the structure of a multilayer board and various structural elements is given, allowing to limit (screen) the signal in a small volume, commensurate with the size of a monolithic integrated circuit or a set of monolithic integrated circuits, isolating parasitic electromagnetic interference. Polyimide is considered as a dielectric material of a multilayer microwave board for use in space technology devices, as well as promising design solutions for reducing the mass and dimensions of the module.
The paper considers prospective directions of improving consumer services rendered with the help of multi-satellite space systems. Based on a study of trends in the development of thematic geoinformation services, the conclusion is made about the need to form personalized complex queries, including those containing suggestions concerning putative solutions for the mass user. The multi-satellite space infrastructure currently under development, which is considered as a single space information system, can serve as the technical means for adopting such an approach. Based on an analysis of development trends of the existing system of geoinformation support, a conclusion is made about the feasibility of the intellectualization and personalization of services, which are targeted at a specific customer, with the expansion of the range of possible consumers to a mass individual consumer. The article proposes several approaches, the further development of which can result in the creation of system-wide services that implement the “from data to solutions” concept at the level of integrated solutions.
The present article addresses the results of the “Meteor-M” No. 2-2 SAR payload (RK–SM–MKA) commissioning campaign. The international effort was coordinated by Russia with the participation of technical teams from national administrations of the United States, Canada and France. In the course of testing, it was determined that the SAR payload performance was within technical expectations and that the SAR payload could be operationally used in the COSPAS–SARSAT system. Other matters of integrating the “Meteor-M” No. 2-2 (“Cospas-14” in Cospas-Sarsat terminology) SAR payload into the COSPAS–SARSAT system as well as the system’s readiness to accept the new spacecraft are discussed. The article also unveils the objectives addressed during the “Сospas-14” integration period and the benefits gained by the system, which were recently made public by the COSPAS–SARSAT Secretariat. The analysis performed by the Secretariat demonstrated that the addition of the new “Cospas-14” into the LEOSAR system significantly improves LEOSAR satellite latency due to the spatial diversity of the current SARSAT and “Cospas-14” orbits.
The article is devoted to the study of the energy and frequency efficiency of frequency modulated signals with a continuous phase. The values of efficiency indicators obtained from the results of the study made it possible to supplement the existing diagrams of the efficiency of telemetric radio lines with new values. The results of the work simplify the task of selecting signals to ensure information exchange via telemetric radio lines of the cluster under the conditions of restrictions imposed on energy resources. The analysis of efficiency indicators of angular modulation methods used in modern telemetry systems is carried out. The features of the cluster construction of the orbital constellation of small spacecraft are taken into account. The use of frequency modulated signals with a continuous phase is proposed, which makes it possible to increase the energy efficiency of telemetry radio lines due to intersymbol phase connections inherent in this class of signals. Based on the results of the simulation, the values of performance indicators for the proposed signals are determined. Intersymbol phase connections were taken into account using the Viterbi algorithm. The values of the modulation indices of frequency modulated signals with continuous phase, which are of practical interest, are determined. The use of the proposed signals makes it possible to obtain an energy gain of up to 3 dB in comparison with the signals used at present. The values of the modulation indices, the use of which is impractical, are highlighted.
The paper considers the use of the lattice packing theory for Integer Precise Point Positioning (Integer PPP) with the errors usually not exceeding 1–3 cm based on GNSS signals with code division multiple access (CDMA). Positioning is carried out by processing ionosphere-free linear combinations of code and phase measurements with ambiguity resolution employing satellite corrections. The main issue of PPP algorithms is overcoming the rank deficiency problem of the linear equation system obtained by linearization of nonlinear mathematical models of measurements. Nowadays Float PPP is quite well developed, where rank deficiency is tackled by combining systematic biases in measurement models with integer carrier phase ambiguities. As a result, the number of unknowns is reduced to the rank of design matrix, which allows unambiguous estimation of precise user coordinates and values of new variables generated by the performed combinations. However, under such conditions the information about integer nature of carrier phase ambiguities is lost, and this leads to a significant increase in convergence time to obtain user coordinates estimates with the errors of 1–3 cm. It is possible to involve the information on the integer nature of phase ambiguities into processing by applying ambiguity resolution algorithms. Though, as a result of the conducted combinations, the integer nature is destroyed, which makes it impossible to apply these algorithms. In Integer PPP rank deficiency is overcome by projecting the state space of the initial linear equation system onto a so-called S-space, whose dimension is equal to the rank of this system. The orientation of the S-space and the direction of projecting are chosen so that the variables of the initial system corresponding to user coordinates are not changed during the projecting and the projections of integer variables remain integer. This makes it possible to estimate precise user coordinates involving information on the integer nature of phase ambiguities. In the literature on Integer PPP based on CDMA GNSS signals processing the description of the S-space orientation with the desired properties is given, but there is no description of the method to determine this orientation. This paper based on the notions of the lattice packing theory considers an algorithm for determining the S-space with the desired properties. It is shown that there exists an infinite set of such S-spaces connected by unimodular transformations, and a technique is proposed to enable selection from this set the S-space, which requires minimal computational cost. The use of the lattice packing theory to the Integer PPP network solution with CDMA GNSS signals will be considered in the following publication of the authors.
Using of lattice packing theory for computation of precise satellite clock corrections based on measurements from a ground network of GNSS CDMA signals (network solution) is considered. Advantage of lattice packing theory for this task solution in comparison with algebraic graph theory is described. Network solution based on of algebraic graph theory was considered in previous paper of the authors [3]. The precise satellite clock corrections are transmitted into the user receiver and applied to get the user coordinates with the errors usually not exceeding 1–3 cm. Ambiguity resolution of carrier phase measurements is used to get such precise satellite clock corrections; it leads to a considerable increase in positioning accuracy and a significant reduction of convergence time for user solution.
The article focuses on the issues of creating promising space technologies, their general characteristics, and special features. The basic principles for creating and implementing key navigation-ballistic technologies, which help ensure efficient control of spacecraft, are substantiated. A classification of the technologies is proposed based on the characteristics most often used in the area under consideration. Two bar charts of a typical technological cycle of navigation-ballistic support with the possibility of processing a joint sample of measurements of current navigation parameters and recurrent Kalman processing algorithms are analyzed. A variant of a general classification of technologies that allows singling out and correlating different types and classes of technologies is given. This contributes (especially at the early stages) to the improvement of the efficiency of their development.
. The present paper is devoted to the design of a new shielded metal-dielectric waveguide with low losses (less than 0.5 dB/m) and wide bandwidth for the 90–100 GHz frequency range. Various types of waveguide structures were analyzed, such as metal waveguides, oversized metal waveguides, dielectric waveguides, dielectric waveguides with a metal shield and various designs of the dielectric filling element. Estimates of loss per unit length in them are obtained. The design of a waveguide containing an oversized round metal screen and a dielectric element consisting of a plate and a rod, located in the center of symmetry of the device, is proposed. The task of creating a transition from the investigated waveguide to a standard rectangular metal waveguide is considered. It is a horn transition from a circular cross-section to a rectangular one with a length of more than 25 wavelengths with a dielectric structure continuing the dielectric element of the waveguide path. As a result of the work, the ratios of the dimensions of the structural elements of the waveguide path and the materials used were obtained that satisfy the required losses.
The article considers approaches to the formation of a criteria base to evaluate the effectiveness of the design of advanced space systems on the example of space systems for monitoring the Earth’s gravitational field. The main requirements for creating a criteria base are formulated. The definition of the criterion and generalized criterion of efficiency in relation to the elements of advanced space systems is given. General and specific criteria for the effectiveness of advanced space systems are considered depending on the purpose of a particular system (defense, civil, and multi-purpose).
The article analyzes the relevance of the problem of structuring the integrated system of standardization and certification of space systems, created within the Union State program “Standardization-US”, the scientific novelty of the work and the practical significance of the results obtained. The methodological foundations for automating the corresponding models of the monitoring process are justified to improve the efficiency of technologies and methods for monitoring the design of space systems. As an example of the implementation of the developed system of normative documentation, the possibility of regulating the monitoring of the design processes of space facilities by the provisions of state standards of the Republic of Belarus in the space activities is considered.
