The paper considers the issues of reconstruction of the power disturbing effect on the prototype of the small spacecraft "Aist". The measurements data of the components of the induction vector of the Earth's magnetic field by means of two three-component magnetometers were used for the reconstruction. The obtained results can be used to assess microaccelerations in the internal environment of small spacecraft, as well as to study their uncontrolled rotational motion.

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The article focuses on the development of algorithms for controlling the parameters of the orbit of a geostationary satellite with the help of a low- thrust engine. We consider only the control of two-dimensional parameters that define the position of the satellite in the orbital plane, namely, the orbit time, the eccentricity and the point longitude of satellite observation. A two-dimensional problem of geostationary spacecraft terminal control is formulated. It is assumed that the correction maneuver is carried out by creating low transversal acceleration with the help of low-thrust electric propulsion, and the control vector consists of a sequence of durations of powered and unpowered portions. In this regard, the two-dimensional terminal control problem is solved in a discrete setting. For this purpose, a discrete model of the motion of a geostationary spacecraft in the orbital plane under the influence of low transversal acceleration is developed. It is quite difficult to solve the problem posed by using the traditional method of dynamic programming based on the use of the Bellman equation since the resulting discrete model of the satellite motion is a non-linear system of equations. Therefore, an approximate pattern of solving the problem on the basis of a three-step algorithm of the terminal control of the orbit time, eccentricity and point longitude of satellite observation is proposed in the paper. As a result, the plane terminal control problem is solved in an analytical form. Analytical expressions for estimating the costs of characteristic velocity correction maneuver using a three-step algorithm of terminal control are obtained. In modeling the motion of a geostationary satellite under the influence of low transversal acceleration the algorithm showed sufficiently high accuracy.

The paper considers the problem of control over a large space structure (LSS) control at a given station on a geostationary orbit (GSO). An observation spacecraft with diffractive optical elements (DOE) is taken as an example of a large space structure. Various perturbing factors influence the motion of a LSS along GSO, most notably solar radiation pressure. Two problems are considered: control over the motion of the center of mass, and control of the motion in relation to the center of mass. The paper gives the results of modeling the process of LSS control, based on developed control algorithms.

This article surveys approaches to the selection of design parameters and modelling the functioning of the remote sensing satellite systems, taking into account the requirements and restrictions on customer resources. The objective of this research is to increase the efficiency of the use of space systems to solve urgent tasks of monitoring the earth’s surface. Firstly, an analysis of the requirements for space imagery materials and consumer information support was carried out, secondly, mathematical models of remote sensing equipment and onboard systems of small spacecraft were developed, and finally, a database with the technical characteristics of the onboard systems and remote sensing equipment of spacecraft, launch vehicles and ground-based reception and processing information facilities was created. As a result, software to determine main design parameters and modelling the functioning of cost-effective remote sensing satellite systems was developed.

Abstract. The paper presents a feasibility study for an optical system, based on a diffractive membrane. The authors have analyzed structural design of diffractive optical elements for space application and developed finite element models of diffractive lens's carrier and mount. The models were developed for two different schemes: MOIRE project and for the original scheme, developed by the authors. The schemes were analyzed for structural stiffness of the diffractive lens's carrier and mount. The shapes and frequencies of natural oscillations of the carriers of the lens were calculated. The problems of the membrane system's orbit injection and operation were analyzed. An algorithm for the terminal control of the orbital period, eccentricity and longitude of the point of standing of the orbital surveillance system was proposed.Keywords: diffractive optics, space membrane optical system, finite element modeling, space telescope, geostationary orbit Citation: Salmin VV, Karpeev SV, Peresypkin KV, Сhetverikov AS, Tkachenko IS. Feasibility study and modeling of components for an informational space system based on a large diffractive membrane.

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