Gravity assists maneuver in the problem of extension accessible landing areas on the Venus surface

2021 ◽  
Vol 30 (1) ◽  
pp. 103-109
Author(s):  
Natan A. Eismont ◽  
Vladislav A. Zubko ◽  
Andrey A. Belyaev ◽  
Ludmila V. Zasova ◽  
Dmitriy A. Gorinov ◽  
...  
Keyword(s):  
Gravitational Field ◽  
Entry Angle ◽  
Gravity Assist ◽  
Flight Duration ◽  
The Earth ◽  
Gravity Assists ◽  
Primary Basis ◽  
Venusian Surface ◽  
Research Show

Abstract This study discusses the usage of Venus gravity assist in order to choose and reaching any point on Venusian surface. The launch of a spacecraft to Venus during the launch windows of 2029 to 2031 is considered for this purpose. The constraints for the method are the re-entry angle and the maximum possible overload. The primary basis of the proposed strategy is to use the gravitational field of Venus to transfer the spacecraft to an orbit resonant to the Venusian one – with the aim of expanding accessible landing areas. Results of the current research show that this strategy provides an essential increase in accessible landing areas and, moreover, may provide an access to any point on the surface of Venus with a small increase in ∆V required for launch from the Earth and in the flight duration. The comparison with the landing without using gravity assist near planet is also given.

scholarly journals AN ARTIFICIAL EXPERIMENT AIMED TO SPECIFY THE GRAVITY LAW IN THE SOLAR SYSTEM

Metaphysics ◽  
2020 ◽  
pp. 137-146
Author(s):  
A. P Yefremov
Keyword(s):  
Gravitational Field ◽  
Solar System ◽  
Impact Parameter ◽  
Einstein Gravity ◽  
Test Body ◽  
The Sun ◽  
Space Probe ◽  
Gravity Assist ◽  
The Earth ◽  
Ballistic Trajectory

Ultra-sensitivity of a planet’s gravity assist (GA) to changes of the test-body impact parameter prompts a space experiment testing the nature of gravitational field in the Solar system. The Sun, Earth and Venus serve as the space lab with a primitive space probe (ball) as a test body moving on a ballistic trajectory from the Earth to Venus (rendering GA) and backwards to the Earth’s orbit. We show that in Newton and Einstein gravity, the probe’s final positions (reached at the same time) may differ greatly; an Earth’s observer can measure the gap.

The analysis is geometrically stable orbits of spacecraft remote sensing of the Еarth

2018 ◽  
Vol 15 (1) ◽  
pp. 12-22
Author(s):  
V. M. Artyushenko ◽  
D. Y. Vinogradov
Keyword(s):  
Remote Sensing ◽  
Gravitational Field ◽  
State Vector ◽  
Semimajor Axis ◽  
The State ◽  
Zonal Harmonics ◽  
The Earth ◽  
Conditions Of Stability

The article reviewed and analyzed the class of geometrically stable orbits (GUO). The conditions of stability in the model of the geopotential, taking into account the zonal harmonics. The sequence of calculation of the state vector of GUO in the osculating value of the argument of the latitude with the famous Ascoli-royski longitude of the ascending node, inclination and semimajor axis. The simulation is obtained the altitude profiles of SEE regarding the all-earth ellipsoid model of the gravitational field of the Earth given 7 and 32 zonal harmonics.

Spheric radial basis functions in Mahalanobis measuring for displaying local field features

2019 ◽  
Vol 952 (10) ◽  
pp. 2-9
Author(s):  
Yu.M. Neiman ◽  
L.S. Sugaipova ◽  
V.V. Popadyev
Keyword(s):  
Gravitational Field ◽  
Quadratic Form ◽  
Local Field ◽  
Euclidean Distance ◽  
Basis Functions ◽  
Spherical Functions ◽  
Local Models ◽  
Stationary Field ◽  
Modeling Process ◽  
The Earth

As we know the spherical functions are traditionally used in geodesy for modeling the gravitational field of the Earth. But the gravitational field is not stationary either in space or in time (but the latter is beyond the scope of this article) and can change quite strongly in various directions. By its nature, the spherical functions do not fully display the local features of the field. With this in mind it is advisable to use spatially localized basis functions. So it is convenient to divide the region under consideration into segments with a nearly stationary field. The complexity of the field in each segment can be characterized by means of an anisotropic matrix resulting from the covariance analysis of the field. If we approach the modeling in this way there can arise a problem of poor coherence of local models on segments’ borders. To solve the above mentioned problem it is proposed in this article to use new basis functions with Mahalanobis metric instead of the usual Euclidean distance. The Mahalanobis metric and the quadratic form generalizing this metric enables us to take into account the structure of the field when determining the distance between the points and to make the modeling process continuous.

Motion of a satellite in the earth’s gravitational field

1960 ◽  
Vol 254 (1276) ◽  
pp. 48-65 ◽  
Keyword(s):  
Gravitational Field ◽  
Spherical Harmonics ◽  
Main Part ◽  
Equations Of Motion ◽  
Orbital Elements ◽  
Partial Derivatives ◽  
Rates Of Change ◽  
Zonal Harmonics ◽  
The Earth ◽  
Secular Terms

The equations of motion of a satellite are given in a general form, account being taken of the precession and nutation of the earth. The main part of the paper deals with the motion arising from the gravitational field of the earth, expressed as a general expansion in spherical harmonics. By evaluating the partial derivatives in Lagrange’s planetary equations, • expressions are obtained for the rates of change of the orbital elements. Particular consideration is given to the form of the expressions for the secular terms arising from the first four zonal harmonics.

scholarly journals Approximate Inertial Coordinate System Selections for Rotation Problems - The Gravitational Field of the Celestial Body Higher than the Object Being Rotated

2015 ◽  
Vol 8 (1) ◽  
pp. 102
Author(s):  
Zifeng Li
Keyword(s):  
Gravitational Field ◽  
Coordinate System ◽  
Celestial Body ◽  
Angular Speed ◽  
Calculation Error ◽  
Cartesian Coordinate System ◽  
Inertial Coordinate System ◽  
The Earth ◽  
The Galaxy ◽  
Cartesian Coordinate

<p class="1Body">Selection of the coordinate system is essential for rotation problems. Otherwise, mistakes may occur due to inaccurate measurement of angular speed. Approximate inertial coordinate system selections for rotation problems should be the gravitational field of the celestial body higher than the object being rotated: (1) the Earth fixed Cartesian coordinate system for normal rotation problem; (2) heliocentric - geocentric Cartesian coordinate system for satellites orbiting the Earth; (3) the Galaxy Heart - heliocentric Cartesian coordinates for Earth's rotation around the Sun. In astrophysics, mass calculation error and angular velocity measurement error lead to a black hole conjecture.</p>

scholarly journals The 1964 IAU System and the Geodetic Reference System 1967

1971 ◽  
Vol 9 ◽  
pp. 279-280
Author(s):  
J. Kovalevsky
Keyword(s):  
Gravitational Field ◽  
Reference System ◽  
Geodetic Reference System ◽  
The Earth

In 1964, the IAU adopted, among the primary constants of its system, the following three constants especially related to the shape, dimensions and gravitational field of the Earth:a = 6378160 mGM = 398603 × 109m3/s2J2 = 0.0010827These values were discussed in 1967 by the IAG and adopted by the IUGG as the basis of a ‘Geodetic Reference System 1967’. Although at that time better values of these constants were available, IUGG decided to adopt the values of the IAU system in order to keep consistency with the values agreed upon by the astronomers.

scholarly journals Geodesic Effect Near an Elliptical Orbit

2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
Alina-Daniela Vîlcu
Keyword(s):  
Gravitational Field ◽  
Elliptical Orbit ◽  
Newtonian Mechanics ◽  
The Sun ◽  
Classical Approach ◽  
De Sitter ◽  
Lagrange Equations ◽  
The Earth ◽  
Elliptical Motion

Using a differential geometric treatment, we analytically derived the expression for De Sitter (geodesic) precession in the elliptical motion of the Earth through the gravitational field of the Sun with Schwarzschild's metric. The expression obtained in this paper in a simple way, using a classical approach, agrees with that given in B. M. Barker and R. F. O'Connell (1970, 1975) in a different setting, using the tools of Newtonian mechanics and the Euler-Lagrange equations.

scholarly journals Design Of Lunar-Gravity-Assisted Escape Trajectories

2020 ◽  
Vol 67 (4) ◽  
pp. 1374-1390
Author(s):  
Lorenzo Casalino ◽  
Gregory Lantoine
Keyword(s):  
Lunar Gravity ◽  
Gravity Assist ◽  
Analytical Treatment ◽  
Direct Optimization ◽  
Earth Asteroid ◽  
Combined Use ◽  
Escape Trajectories ◽  
Gravity Assists ◽  
Lunar Gravity Assist ◽  
Near Earth Asteroids

AbstractLunar gravity assist is a means to boost the energy and C3 of an escape trajectory. Trajectories with two lunar gravity assists are considered and analyzed. Two approaches are applied and tested for the design of missions aimed at Near-Earth asteroids. In the first method, indirect optimization of the heliocentric leg is combined to an approximate analytical treatment of the geocentric phase for short escape trajectories. In the second method, the results of pre-computed maps of escape C3 are employed for the design of longer Sun-perturbed escape sequences combined with direct optimization of the heliocentric leg. Features are compared and suggestions about a combined use of the approaches are presented. The techniques are efficiently applied to the design of a mission to a near-Earth asteroid.

Surface gravitational field and topography changes induced by the Earth?s fluid core motions

2004 ◽  
Vol 78 (6) ◽  
pp. 386-392 ◽  
Author(s):  
M. Greff-Lefftz ◽  
M. A. Pais ◽  
J.-L. Le Mou�l
Keyword(s):  
Gravitational Field ◽  
The Earth ◽  
Fluid Core
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