Abstract The geomorphological and geological analysis of the surface of three primary and ten secondary landing ellipses (15 × 30 km) for the Russian Luna-Glob automated scientific station (Luna-25) is presented. The earlier selected landing ellipses are found in the sector of 65°–85° S and 0°–60° E of the lunar southern hemisphere. The geological characteristics of the ellipse include the analysis

Abstract— The results of numerical modeling of the vertical fall of ten-kilometer asteroids onto a solid surface and into an ocean with a depth of 1 to 7 km are presented. The calculations obtained the maximum masses of water and soil emitted into the atmosphere, as well as the masses of water and soil remaining in the atmosphere 30 minutes after the impact. It is concluded that that when asteroids

Abstract The restricted elliptic doubly averaged three-body problem is considered. The terms up to the second order inclusive with respect to the orbital eccentricity of the perturbing body are retained in the expansion of the perturbing function. The elements of the elliptical orbit for the perturbed body are deemed arbitrary. The special, so-called linked orbits of a negligible-mass body are investigated

Abstract— The discovery of the first interstellar comet 2I/Borisov confirmed the astronomers’ speculation that the passage through the solar system of relatively large objects (asteroids and comets) formed outside of it is a common occurrence. There may be many such objects, but their discovery is still a rare case. Large professional telescopes and existing observation programs with these telescopes

Abstract— Within the framework of Tsallis nonextensive statistics, the criteria for the Jeans gravitational instability are derived for a self-gravitating protoplanetary disk, whose substance consists of a mixture of a conducting ideal q-gas and modified radiation of a photon gas. The instability criteria are derived from the corresponding dispersion relations written for both neutral disk matter and

Abstract The paper considers the free molecular flow of gas through the dusty porous surface layer of a comet nucleus. The study is based on computer models of generation of a porous medium and Knudsen gas diffusion. We consider various types of homogeneous and heterogeneous layers constructed from nonintersecting spheres, including layers that contain microcracks or inner cavities. Using the test-particle

Abstract In the current investigation we have studied the distribution as well as the asymmetry of solar X-ray flares during the period 1976–2017 which corresponds to solar cycle 21, 22, 23 and the almost complete solar cycle 24. The study of the N–S distribution of soft X-ray flares during solar cycles 21, 22, 23 and 24 reveals that the 10°–20° latitude band produced maximum number of soft X-ray flares

Abstract We estimate the contribution of the molecular hydrogen dissociation processes, which are induced by the extreme UV radiation and the accompanying flux of photoelectrons, to the formation of a fraction of suprathermal atomic hydrogen in the Н2 → Н transition region and the corresponding escape flux from the extended upper atmosphere of an exoplanet—the hot Neptune GJ 436b (Gliese 436b). We

Abstract A collision of an asteroid with the Earth in the future is always considered as a probabilistic event because the asteroid orbit determined from observations with random errors inevitably contains an uncertainty in its parameters. To establish the probability of collision, the parametric uncertainty as a probabilistic distribution of virtual objects is mapped by the orbital model into the

Abstract We consider the issue of choosing the reference surface for the analysis of data on the topography and the gravitational field of Venus. The hypothesis of the Earth-like Venus is used. The surface of an effectively equilibrium Venus, which survives from an earlier epoch, is chosen as a reference. For a set of the Earth-like models of the internal structure of Venus, the equilibrium figure

Abstract We present the results of geological and morphological analysis of LROC NAC images of a small volcanic crater Ina, D-shaped in plan view (2.9 × 1.9 km), and its immediate surroundings. This crater is located at the top of a very gently sloping shield volcano, the slopes of which, judging by the density of superimposed small craters, were formed ~3.5 Ga ago. Inside the crater there is a region

Abstract We report the results of multicolor optical observations of asteroid (3552) Don Quixote carried out at the Zeiss-1000 telescope of the Sanglokh International Astronomical Observatory of the Institute of Astrophysics of the Academy of Sciences of the Republic of Tajikistan in July 2018. The apparent and absolute magnitudes of the asteroid were determined in the VRI bands. The analysis of the

Abstract The relief spectra of the Moon, Mars and Earth with a very high resolution are discussed (Rexer and Hirt, 2015). According to the Kaula rule (Kaula, 1966), these spectra decay as \({{k}^{{ - 2}}}\). This fact has been recently explained (Gledzer and Golitsyn, 2019) based on the probabilistic laws by Kolmogorov and his school (Kolmogorov, 1934; Obukhov, 1959; Monin and Yaglom, 1967; Golitsyn

Abstract— The article considers the attitude stability of synchronous rotation and the most significant relativistic effects in the rotational dynamics of the inner satellites of Jupiter: Metis (J16), Adrastea (J15), Amalthea (J5), and Thebe (J14). It is established that the plane synchronous rotation of all inner satellites of Jupiter for the most probable values of the parameters of their shapes

Abstract The radio occultation measurements of the signal intensity (λ = 32 cm) of the Venera-15 and -16 satellites, carried out from October 16 to October 31, 1983, are used to analyze the activity of internal waves in the northern polar atmosphere of Venus. Observations of the intensity of radio waves provide important information about the fine-scale structure of the planet’s atmosphere. Comparison

Abstract Based on the spectral observations of Jupiter carried out over recent years, we consider the behavior of weak molecular absorption bands of methane and ammonia in a wavelength range of 600−800 nm. In the latitudinal behavior of the intensity of these bands, rather clearly expressed features, demonstrating a connection with the zonal structure of cloud belts of the planet, are traced. However

Abstract The article presents an overview of some design features of the development of transformable structures of space telescopes as well as descriptions of real projects in which these features have been implemented.

Abstract The paper describes theoretical issues of the motion of gaseous thermal decomposition products of composite materials in a porous frame structure under the effect of intensive heat flows of different nature. The developed model was verified using benchmark filtration problems and its performance was tested for gas motion using the sample with the porosity that varied in coordinates.

Abstract The article presents the results of research carried out in the development of technology for soldering pipelines of small diameter of aluminum alloys and dissimilar materials. The advantages of the alternative design of the collector of the heat exchanger of the spacecraft with brazed joints in comparison with bimetallic adapters and ring argon arc seams are shown. A comprehensive assessment

Abstract To increase the safety of interplanetary missions, it is necessary to have estimates of the meteor hazard along the flight trajectory. Meteoroid particles of known meteor showers that cross the ecliptic plane at a distance of 1 AU from the Sun are observed as “shooting stars” in the Earth’s atmosphere. However, such meteor streams are principally not observable in interplanetary space. The

Abstract— A method for exciting the detonation process and its development in onboard low-pulse shatter-proof separation devices and in the units for initiating detonation equipped by high-energy elastic materials (HEEM) is examined. The relationships for calculating detonation initiation reliability for the HEEM charge are presented and practical recommendations for increasing it are given.

Abstract—Results of the implementation of a single concept for the development of the double launch system (SDZ) are presented, in particular the SDZ-La5 for the Fregat-SBU upper stage. Design and functional solutions are defined for the SDZ-La5 application as a part of RBF2U-SBU which differs in its geometry and mass-inertia properties from the Fregat upper stage (RBF). Information is presented on

Abstract The possibility of determining the thermophysical characteristics of the lunar soil by a penetrating probe when using solar heat as a heater is considered. The effectiveness of this measurement method is evaluated.

Abstract The article presents the prognostic capabilities of the SOCOL global climate model. A correction of the trajectory is proposed by supplementing the algorithms of the nominal control of the return vehicle with the atmospheric parameters at altitudes of 40–80 km obtained as a result of prognostic calculations.

Abstract An analysis of various schemes for coolant motion in a nuclear reactor with spherical microfuel elements (coated fuel particles, or pebbles) is presented. The conditions under which it is possible to reduce the pressure losses in the coolant keeping all the advantages of the spherical microfuel elements versus the fuel rods are considered. The rate of coolant flow and the pressure losses in

Abstract The “Bumerang” space mission to the satellites of Mars is discussed. The purpose of the mission is to study the satellites and return of soil samples from Phobos to the Earth. The previous such missions to Mars are revisited. To increase the chances of success of the “Bumerang” mission, it is proposed to carry out a preemptive demo flight to a small asteroid, ahead of the mission. The goal

Abstract—The paper analyzes the Russian scientific and technological capabilities to manufacture a space-borne observation platform for high-precision monitoring of the Earth’s gravitational field. It is shown that some Russian space systems manufacturing technologies may well be used for this purpose; however, in general, the level of the domestic technologies must be substantially improved so as

Abstract During ground-based thermal vacuum tests of spacecraft, it is necessary to control and monitor the change in dust content in closed and semiclosed hollows of the spacecraft, near the optical surfaces of scientific and service hardware, mirrors, solar arrays, multilayer insulation, as well as in the volume of the thermal-vacuum chamber itself during its evacuation etc. It is known that the

Abstract The article presents aspects of the use of inflatable decelerators in the design of spacecraft (SC) intended for the study of the atmosphere of Venus. The results of the aerothermodynamics calculations and justification of the thermal protection of SC with decelerators are given. Their advantages over conventional descent modules during aerodynamic deceleration in the planet’s atmosphere are

Abstract— Astronomical space telescopes with large apertures of various spectral ranges have become one of the main tools of exploring the Universe. Conventional technologies do not allow increasing the space telescope aperture above several meters. This article describes the conceptual design of an UV and IR On-orbit Assembling Space Telescope (OAST) with an aperture of 10 m. Unlike conventional space

Abstract A model and a software module were developed to analyze the shape of the trajectory described by the subsatellite point on the Earth’s surface depending on eccentricity, perigee angle, and inclination of the geosynchronous orbit (GEO). For various parameters of the satellite’s orbit and synthetic aperture radar (SAR) equipment, we built the dependences of the geometric resolution in the longitudinal

Abstract— We examine system problems in developing launch vehicles in the ultralight class as a modification of the basic meteorological rocket. Reasonable parameters for the ultralight launch vehicle of such type are determined. It is shown that this project can be implemented efficiently.

Abstract Problems on optimizing the noncoplanar flights with low thrust from elliptical to geosynchronous orbits for different control accelerations are solved. Recommendations for choosing an initial approximation are given. The results are compared with the results obtained by other authors.

Abstract The dose effect on the onboard equipment of the lunar rover from ionizing radiation from outer space and from radioisotope sources intended for providing the thermal regime of the spacecraft in a lunar night are considered. Calculations are made to determine the requirements for radiation hardness of devices and their components, as well as the possibility of using the instrumentation reserve

Abstract The article presents the calculation technique and the results of a study of the penetration of hot gas from the shock layer into the internal space of the prospective descent module due to leakage of the structure of the vehicle during descent in the Martian atmosphere.

Abstract The paper describes a modified smooth approximation method for smoothing the dependence of the equivalent fluence of charged particles of the Earth’s Van Allen radiation belts on time and position in near-Earth space. It is shown that this method can be effectively used to solve the problems of minimizing radiation-induced degradation of spacecraft solar cell arrays. The latter problems involve

Abstract The effect of the preferred orientation of the largest axis of the satellite’s figure toward the planet during chaotic rotation is considered by means of numerical experiments. It has been found that the effect is most noticeable in the chaotic dynamics of small satellites with an orbital eccentricity e ≤ 0.005; this may impede the identification of the chaotic rotation of the satellite if

Abstract— The aim of this paper is to construct the thermodynamics of open quantum systems of elementary Bose-gas particles in the framework of nonextensive Tsallis statistics based on modified quantum entropy, which depends on the real deformation parameter \(q.\) We obtain generalized expressions for the thermodynamic potential, internal energy, free energy, specific heat, and pressure, as well as

Abstract The paper discusses three types of processes of destruction of small lunar craters: (1) destruction by overlapping craters; (2) destruction due to filling with ejecta from neighboring and remote craters; and (3) destruction due to the displacement of surface material by various slope processes. These processes act together, but the role of each in a specific situation and at different stages

Abstract— A model for generating electromagnetic fields in the ELF/VLF range accompanying the final stage of the evolution of meteorites in the Earth’s atmosphere is presented. The phenomenon of low-frequency radio emission is an experimentally proven fact; however, the currently known generation models are not supported by numerical calculations that would not contradict the experimental facts. The

Abstract The problem of matching models of the internal structure of partially differentiated Titan with experimentally measured values of Love number k2 (Iess et al., 2012; Durante et al., 2019) according to results of studying the gravity field of Titan based on flights of the Cassini spacecraft is discussed. The values of k2 obtained presumably point to the presence of large masses of liquid (ocean)

Abstract The impact crater formation on the surface of the Earth and other planetary bodies is accompanied by the action of shock waves on rocks and their displacement into a new position. The shock-wave compression results in the occurrence of the remanent heating of rocks (up to melting and evaporation during the unloading). The direct mechanical action of the shock compression and the remanent heating

Abstract We compare the number of lunar craters larger than 15 km across and younger than 1.1 Ga to the estimates of the number of craters that could have been formed for 1.1 Ga if the number of near-Earth objects and their orbital elements during that time were close to the corresponding current values. The comparison was performed for craters over the entire lunar surface and in the region of the

Abstract We consider prospects for investigating asteroids with the multicolor photometric method at the Robophot telescope—a robotic telescope of the Dall–Kirkham system with a 0.6-m primary mirror and a focal length of 4.2 m. It is equipped with a three-channel photometer with the g', r', and i' filters of the SDSS photometric system, and the field of view is 20′. The use of a three-channel photometer

AbstractThe outer version of the restricted elliptic three-body problem, where a perturbed body of negligible mass is far from two bodies of finite masses (the main and perturbing ones) close to one another and its orbit is located entirely outside the orbit of the perturbing body, is considered. The terms up to the fourth order inclusive in the ratio of the orbital semimajor axes of the perturbing

AbstractAn active region (AR) of the sun is an area of strong magnetic field. Sunspots are frequently formed in an AR. Solar activity exhibits in the form of solar flares and coronal mass ejections. Solar active region AR12 192 occurring on October 18, 2014 hosted the largest sunspot of the 24th solar cycle which was of the size of Jupiter. AR12 192 was ranked 33rd largest active region out of 32908

AbstractWe present the results of the re-reduction of Pulkovo photographic plates with images of Saturn’s major satellites in the Gaia DR2 catalog system (169 plates, 3007 individual positions). Astronegatives were taken with the 26-inch refractor at the Pulkovo Observatory between 1972 and 1982. The intrinsic accuracy of measurement of astronegatives using the Pulkovo MDD system was 1 μm (20 mas on

Abstract—We consider space expeditions with a long-term spacecraft stay near the studied celestial body (artificial satellites of small bodies of the Solar System), or expeditions with a possible spacecraft landing on the surface of the celestial body (for example, the ESA Jovian Icy Moon Explorer JUICE mission, and the Russian prospective project Laplace‑P). An effective formalism is proposed for

AbstractOne of the probable sources of water and other volatiles, forming ice deposits in the shadowed polar regions of the Moon, is cosmic matter delivered by comets and asteroids, as well as by cosmic dust. In this connection, we estimated the contribution of volatile components to the material received due to micrometeoroid bombardment. From the estimates of the current flux of micrometeoroids to

AbstractLaser ionization mass spectrometry is one of the most promising methods for analysis of the elemental and isotopic composition of solids in space experiments: the required instruments are highly reliable and easy to operate, no sample preparation is needed, and the spatial resolution of this method is relatively high. In view of this, the LASMA-LR laser ionization mass spectrometer was included

AbstractThe paper presents the scientific tasks, description, and comparison of various gamma and neutron spectrometers that can be installed on board a medium-class lunar rover with a mass up to 100 kg. As a specific example, we consider the scientific equipment proposed for the future Russian mission Luna-Grunt, the main purpose of which is the delivery of lunar polar regolith samples to the Earth

Abstract—The paper presents the results of a study of the dynamic structure of near-Earth orbital space in the 1 : 2 resonance region with Earth’s rotation speed. The results of an extensive numerical-analytical experiment to study the orbital evolution of objects moving in the semimajor axis range from 26 550 to 26 570 km, with inclinations from 0° to 180°. In this region, the zones of action of the

Abstract—The possible distribution of density and stress anomalies in the interior of the Moon is determined. For this purpose, we have developed a new solution of the incorrect inverse gravimetry problem developed by the authors, tested for the Earth and Mars. The idea of this solution is that the isostatic compensation depths are uniquely determined for the harmonics of the expansion of the relief

AbstractThe review of both previously used lunar deep-hole soil-sampling tools (DSSTs) and new prototypes of these devices, developed for exploring the lunar polar regolith in future lunar projects, is presented, and the DSST options with different technical parameters and layout arrangements intended for future Russian lunar missions are also considered.

AbstractFor the first time, abundances of the main xenon components (Xe-P3, Xe-P3(fr), Xe-P6 and Xe-pr instead Xe-HL) in the nanodiamonds of Orgueil (CI), Tieschitz (H3.6) and Indarch (EH3-4) meteorites have been calculated. The Xe-pr component is the excess fraction of xenon isotopes in the Xe-HL component relative to Xe-P3 (fr) and mainly consists of the 124, 126, 134, 136Хе isotopes formed in p-

AbstractWe analyze the mass distributions of exoplanets of three groups: transit planets discovered by the Kepler telescope, those found in ground-based observational programs and with the CoRoT satellite, and planets discovered in the vicinity of red dwarfs (M class) with the radial-velocity method. The dependence of the mass distributions of the Kepler transit planets on the spectral class of the

AbstractWe perform a statistical analysis of 926 confirmed falls of meteorites that occurred in the period 1860 to 2017. The distribution of meteorites over masses is approximated with a lognormal law. It has been shown that the mean interval between the detections of falls of Chelyabinsk-like meteorites is ~25 years. The time dependence of the annual number of meteorite falls is analyzed with the

AbstractIn relation to the problem of accumulation of dust particles, which are the main structure-forming element of planetesimals in a protoplanetary cloud, we propose a parametric method of moments for solving the Smoluchowski integro-differential equation that describes dispersed coagulation of disk matter. We consider a parametric approach to finding the size distribution function of protoplanetary

Abstract—We analyzed the dynamic evolution of a number of young asteroid pairs in close orbits in order to constrain their ages. Several methods of pair selection and estimation of their age are used: analysis of convergence of orbital elements; estimation of the Kholshevnikov metrics in the space of Keplerian orbital elements; estimation of relative distances and velocities at the moments of asteroid

AbstractThe studies of the composition and structure of comet 67P/Churyumov–Gerasimenko—a short-period comet of Jupiter’s family—which was an object of the recent Rosetta–Philae space mission, yielded results unique in many respects, since it was the first time that a comet was investigated in situ for a long stretch of time under varying conditions of insolation and activity. Due to the landing of