On increasing the spectral efficiency and transmissivity in the data transmission channel on the spacecraft–ground tracking station line

The algorithms for achieving a practical increase in the rate of data transmission on the space-craft–ground tracking station line has been considered. This increase is achieved by applying spectral-effective modulation techniques, the technology of orthogonal frequency compression of signals using millimeterrange radio waves. The advantages and disadvantages of each of three algorithms have been revealed. A significant advantage of data transmission in the millimeter range has been indicated.     

Superluminous Supernovae

Superluminous supernovae are a new class of supernovae that were recognized about a decade ago. Both observational and theoretical progress has been significant in the last decade. In this review, we first briefly summarize the observational properties of superluminous supernovae. We then introduce the three major suggested luminosity sources to explain the huge luminosities of superluminous supernovae, i.e., the nuclear decay of ⁵⁶Ni, the interaction between supernova ejecta and dense circumstellar media, and the spin down of magnetars. We compare these models and discuss their strengths and weaknesses.     

To a problem of aircraft control system design with given dynamic parameters

In the design of an aircraft at the stage of selecting its geometrical parameters, a method is proposed for evaluating the performance capabilities of manual control to ensure the quality of a given flight stabilization mode. The attainability of the given aircraft-pilot dynamic properties is evaluated by a frequency-domain method for permissible values of the aircraft and the pilot model parameters. The quality of the manual control for the longitudinal motion of the aircraft is evaluated.     

Synthesis of control laws for aircraft lateral motion at the lack of data on the slip angle: Analytical solution

The problem of lateral motion stabilization is analytically solved for the fourth-order model of aircraft motion using the method of output signal control synthesis that is based on the control object decomposition. Numerical simulation data are presented.     

Stress–strain analysis of a thin-shell part of fuselage using a triangular finite element with lagrange multipliers

We developed a triangular discretization element of the fuselage fragment in the form of a thin shell compatible with the adjacent elements based on Lagrange multipliers. Solution of several test problems showed a high efficiency of using the modification of a triangular finite element being proposed.     

Determination of parameters of attitude motion of a small communication satellite using the data of measurements of current of solar panels

A communication satellite (small spacecraft) injected into a geosynchronous orbit is considered. Flywheel engines are used to control the rotational spacecraft motion. The spacecraft after the emergency situation has passed into a state of uncontrolled rotation. In this case, no direct telemetric information about parameters of its rotational motion was accessible. As a result, the problem arose to determine the rotational satellite motion according to the available indirect information: current taken from the solar panels. Telemetric measurements of solar panel current obtained on the time interval of a few hours were simultaneously processed by the least squares method integrating the equations of rotational satellite motion. We present the results of processing 10 intervals of the measurement data allowing one to determine the real rotational spacecraft motion and to estimate the total angular momentum of flywheel engines.     

Geometrical simulation of regular and irregular folded structures

Some general problems on simulation of folded cores are considered. The application potential of the present-day parametrical CAD systems for designing constructions based on the regular and irregular structures is shown.     

On choice of turbulence models and grid parameters for computation of flows in diffuser ducts

The results of analyzing the reliability of six turbulence models are presented as applied to calculations of flows in the asymmetric plane diffuser. The influence of grid parameters upon the calculation results is studied and the accuracy of flow separation and reattachment points prediction is determined. Also carried out is the comparison of processor time spent for calculations with the aid of each model.