Motion Of Artificial Earth Satellites Research Articles

Approximate evaluation of the duration of the orbital motion of artificial Earth satellites taking into account light pressure

Approximate evaluation of the duration of the orbital motion of artificial Earth satellites taking into account light pressure

Two modes of the angular motion of artificial Earth satellites

A brief survey of the dynamics of artificial satellites with passive gravity-gradient and magnetic attitude control systems is presented. As examples, the parameters of such are computed for two nanosatellites in which interaction with the geomagnetic field is employed, implying stringent restrictions on mass, volume and energetics. The basic functions relating the characteristics of the motion to the parameters of such satellites are presented.

The accuracy of calculation of orbits of best approach

A new formulation and solution of the problem of calculation of orbits of best approach is discussed. A qualitatively analytical approach to the organization of observations of the motion of artificial Earth satellites is used that makes it possible to calculate and to allow for optimal celestial-mechanics conditions, and to eliminate the effect of systematic observation errors, the effect of the Earth's gravitational field, and other regular perturbations on the solution accuracy.

The acting analytical theory of artificial earth satellites

The author considers problems of the practical construction of the analytical theory of the motion of artificial Earth satellites and the relevant computational programme. He reports about the construction of this theory, algorithms and programmes. He also points out their merits, gives assessments of the accuracy of calculations of the coordinates of satellites as well as turning to concrete examples.

Earth albedo effects in the motion of artificial earth satellites

Abstract Different models of the Earth albedo values and geographical distribution are compared. Effects of the local cloud cover on the satellite perturbing acceleration are investigated. Resulting changes of the satellite orbit obtained by the method of numerical integration in the spherical coordinate system are given. It is shown that a sufficiently sensitive microaccelerometer on board a special satellite could significantly improve existing models of the Earth albedo.

Mathematical model of constraint problem of three bodies in noninertial reference system

Many problems in the study of the motion of artificial earth satellites involve the introduction of a nonrotating geocentric system of coordinates [i, 3]. Such a system is not an inertial one, principally because of the earth's rotation about the barycenter (center of gravity) of the earth-moon system 9 This gives rise to inertial force perturbations, quite largely affecting high-altitude and particularly geostationary satellites [2]. In accordance with the principle of relativity pertaining to compensation of noninertial reference systems, it is necessary to add d'Alambert inertia forces to the active forces of gravitation. On the basis of the formulation [3, 7] of the boundary-value problem of three bodies, those forces can be determined through reversing the problem of two bodies and correctly accounting for the variability of the elliptical parameters of the orbit in which the perturbing body moves. The boundary-value problem of three bodies, its approximate solutions and integrals were used in earlier studies [4, 6] for calculating the trajectories of artificial cosmic bodies.

Asymptotic methods of integrating the equations of motion of artificial earth satellites in the presence of aerodynamic forces

Asymptotic methods of integrating the equations of motion of artificial earth satellites in the presence of aerodynamic forces

Analysis of the integrals of the equations of motion of artificial earth satellites in the normal gravitational field of the earth: N. D. Kislik: (pp. 23–52)

Analysis of the integrals of the equations of motion of artificial earth satellites in the normal gravitational field of the earth: N. D. Kislik: (pp. 23–52)

Dynamic effects in the motion of artificial earth satellites

The announcement of the discovery of messenger RNA (mRNA) and the cracking of the genetic code took place within weeks of each other in a climax of scientific excitement during the summer of 1961. Although mRNA is of decisive importance to our understanding of gene function, no Nobel Prize was awarded for its discovery. The large number of people involved, the complex nature of the results, and the tortuous path that was taken over half a century ago, all show that simple claims of priority may not reflect how science works.

Effect of a Resisting Couple on the Rotational Motion of a Rigid Body

IN a recent communication1, Nonweiler demonstrates the proposition that an external couple applied to a rigid body about its instantaneous axis of rotation in the sense opposing its rotation tends to cause the axis to approach the axis of greatest moment (provided that the instantaneous axis is not initially that of a permanent rotation). He refers to the rotational motion of artificial Earth satellites and the manner in which their instantaneous axes of rotation have been observed to approach the axis of greatest moment and suggests that this theorem may be relevant.

Dynamic effects in the motion of artificial earth satellites: ∗L. L Sedov: (pp. 3–9)

Dynamic effects in the motion of artificial earth satellites: ∗L. L Sedov: (pp. 3–9)

Effect of a Resisting Couple on the Rotational Motion of a Rigid Body

THE examination of the effect of external couples upon the rotational motion of artificial Earth satellites has been of interest, in view of the rapidity with which their instantaneous axes of rotation have been observed to approach the axis of greatest moment, even when they have been initially spun about the axis of least moment. In this particular problem the role of internal energy dissipation due to non-rigidity may in fact be important, but, setting this aside, the theorem set out below appears relevant. This states a well-known principle and many of its corollaries have been proved; however, I have been unable to trace any direct reference to the proposition, or its converse, and would be grateful if any reader could do so.

Formula for Inferring Atmospheric Density from the Motion of Artificial Earth Satellites

Formula for Inferring Atmospheric Density from the Motion of Artificial Earth Satellites

High-Altitude Atmospheric Density

Atmospheric density values obtained from the motion of artificial earth satellites, at altitudes between 186 and 656 kilometers, are discussed. There is some doubt about the reliability of densities from satellites because of the effects of ionization and, in the case of nonspherical satellites, because of their orientation. Densities inferred from satellites are higher than for the ARDC model of the atmosphere. These densities are about ten times higher than densities inferred from rocket-borne ionization gauges between 186 and 230 kilometers. The inference of atmospheric density from rocket-borne ionization gauges is discussed critically, and densities so obtained are considered to be inferior in reliability to the satellite densities. The satellite densities suggest molecular scale temperatures higher than those of the ARDC model in one or more regions of altitude above 80 kilometers.