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The paper considers the possibility of cargo relocation without fuel costs along a tether connecting two heavy space stations by a spacecraft with a controlled solar sail. The spacecraft's relative motion dynamics is studied within the context of a model problem that assumes that the stations describe one heliocentric orbit, the solar sail is a perfect reflective flat panel, and the tether realizes an ideal unilateral handrail constraint that restricts the spacecraft relative motion to an ellipsoid. It is noted that, if the distance between stations is sufficiently small and the ratio of the sail area to the spacecraft mass is on the same order of magnitude as in already-implemented space missions, solar radiation is the main factor that influences the spacecraft's motion in the orbital frame of reference. The problem of searching a set of pairs of points, between which relocation with a permanently oriented sail is possible, is solved for the pairs that belong to the intersection of the ellipsoid boundary and the plane of the stations' orbit. The duration of the spacecraft relocation between the ellipsoid poles is estimated for the case of the sail oriented orthogonally to the solar rays. Also, the duration of the fastest relocation between poles is computed using special sail orientation control laws, including the case of zero initial and final velocities. [ABSTRACT FROM AUTHOR]

The structure and evolution of the passive continental margins of the Arctic Ocean are considered on the example of the South Kara Basin. Its development is associated with the evolution of the West Siberian Plate and the formation of the Arctic Ocean. Until the Late Cretaceous, the South Kara Basin was the north margin of the West Siberian Plate, whose formation is related to the Permian-Triassic processes of riftogenesis accompanied by the eruptions of traps. In the Mesozoic, due to the opening of the Arctic Ocean, the South Kara basin became a part of the continental margin, where the accumulation of marine sandy-clayey rocks continued. [ABSTRACT FROM AUTHOR]

On the basis of reflected wave hodographs interpreted by the method of homogeneous functions, the section of the lithosphere across the Caucasus, Caspian Sea and Turan Plate was obtained without the use of any preliminary section model. In a section of more than 1000 km, mantle and crustal structures and junction patterns between them are seen down to 60 km within the limits of the Kura Basin and the South and Middle Caspian basins and the Turan Plate. The section of the South Caspian Basin is generally consistent with the ideas of E.V. Artyushkov concerning its structure. A sedimentary layer of up to 30 km thick is underlain by a thinned crust about 10 km thick and by high-velocity mantle. The Turan Plate consists of three layers, which are typical for cratons that are about 50 km thick. [ABSTRACT FROM AUTHOR]

In the numerical solution of the diffraction problem for an acoustic plane wave in a half-plane with a cut, boundary conditions that are equivalent to the radiation conditions at infinity are set in a neighborhood of the points of the cut. Joining the physical boundary conditions on the cut, a closing set of equations of order 4 N, where N is the number of grid points on the cut, is obtained. The so-called Green’s grid function for the half-plane is used, which makes it possible to pass from one grid layer to another one for the solution satisfying certain conditions at infinity. [ABSTRACT FROM AUTHOR]

This paper discusses the results of interpreting seismic profiles on the Earth’s crust of the Maritime Territory and Sea of Japan performed during the 20th century by the Sakhalin Integrated Research Institute and by the Schmidt Joint Institute of Physics of the Earth, Russian Academy of Sciences. The seismic profiles confirmed the presence of structural features under the Maritime Territory and the Sea of Japan that were revealed previously from geological data, such as spreading zones, rifts, deep-seated faults, overthrusts, and subduction zones, suggesting an active type of continental margin in the Far East region. We assumed that a high occurrence of the asthenospheric layer enclosing magmatic chambers explains the high activity of tectonic processes in the Far Eastern continental margin. The identified system of rifts and spreading centers supports this assumption. [ABSTRACT FROM AUTHOR]

This paper provides information on the first International Polar Year, International Geophysical Year, and the data on the study of the Earth within these programs. [ABSTRACT FROM AUTHOR]

Equilibrium positions of a small-mass body are considered with respect to a precessing dumbbell. The dumbbell represents two rigidly fixed spherical gravitating bodies. Such a system can be considered as a model of a binary asteroid. Stability of relative equilibrium positions with equal distances from the small mass to the attracting centers is studied. By analogy with the classical restricted three-body problem, these positions are referred to as triangle libration points. It is shown that the character of stability of these libration points is determined by three constant parameters: nutation angle and angular velocity of precession, as well as the ratio of masses at the ends of the dumbbell. Stability conditions are derived in the linear approximation, and the regions of stability and instability in the space of problem parameters are constructed. The paper is a continuation of [1]. [ABSTRACT FROM AUTHOR]

The paper demonstrates that in computing a linear form (g, x) on the solution of a system of linear equations Ax = f, the round-off error depends on the quantities ‖A−1f‖ and ‖AT−1g‖ rather than on the condition number of the coefficient matrix A. Estimates of the inherent and round-off errors in solving the above problem by the orthogonalization method are provided. Numerical results confirming theoretical conclusions are presented. Bibliography: 8 titles. [ABSTRACT FROM AUTHOR]

The possibility of nonimpact tension of a cable after its weakening when a small load moves along the cable whose ends are fixed on a massive dumbbell-like spacecraft which is moving in a steady-state manner along a circular orbit is considered. The conditions of existence and classification of the trajectories of nonimpact motion, including periodic ones, are presented. [ABSTRACT FROM AUTHOR]

The motion of a space object in the gravitational field of the Earth is considered. The object consists of an extended space station and a weight, which is free to move along the cable fixed to the ends of the station. It is assumed that the station is composed of two masses coupled by a weightless rod, while the cable is weightless and non-stretched. The equations of motion of such a system are derived for the case when the motion proceeds in a single plane, while the center of mass of the system moves along a circular geocentric orbit. The conditions of the cable tension (conditions of being on tie) are derived. The phase portrait of the weight motion along the cable is constructed when the station is oriented to the attracting center or is perpendicular to this position. The possibility to leave the tie in this case is analyzed. Equilibrium configurations of the system are found, i.e., such motions of the object under consideration at which the weight does not change its position relative to the station. Lyapunov stability of such configurations is analyzed for two situations: when the station is composed of equal masses and when masses at the ends of the station are different. In particular, for the case of different masses it is established that there exist such positions of equilibrium at which the dumbbell is located at an angle to the direction to the attracting center. In some cases these positions can be stabilized (if the weight is fixed on the cable). [ABSTRACT FROM AUTHOR]

Examines the motion of a system that represents an elongated space station considered as a system of two material points connected by a weightless rod and load hat can freely move along a cable. Effect of gravitation on the relative motion of the load; Points to consider if the inhomogeneity of the of the gravitational field is neglected; Establishment of the differentiating formulas with respect to time; Determination of the phase portrait of relative motion.

The paper presents the results of geological-geophysical research carried out during the Soviet-Japanese cooperative study of the structure and dynamics of the Earth's crust and upper mantle in the transition zone from the Pacific Ocean to the Asian continent. The 300 km deep geological-geophysical section of the tectonosphere (geotraverse) has been compiled on the basis of combined interpretations of seismic, geological, petrographic, gravimetric, magnetometric, electromagnetic and heat flow measurements. Estimates were made of deep temperatures along the geotraverse and of the depths of the partial melting level that can be identified with the upper boundary of the asthenosphere. [ABSTRACT FROM AUTHOR]

It is proposed to estimate the effects of hydrogen on alloy degradation from the total specific energy Wc of limiting deformation. Data are given on estimating the degradation from Wc for various alloys given various treatments (hydrogenation, heat treatment). [ABSTRACT FROM AUTHOR]