scholarly journals Analysis and Control of Nonlinear Attitude Motion of Gravity-Gradient Stabilized Spacecraft via Lyapunov-Floquet Transformation and Normal Forms

2020 ◽  
Author(s):  
Peter M.B. Waswa ◽  
Sangram Redkar
Keyword(s):  
Normal Forms ◽  
Gravity Gradient ◽  
Attitude Motion ◽  
And Control

scholarly journals Attitude Motion of Cylindrical Space Debris during Its Removal by Ion Beam

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Vladimir S. Aslanov ◽  
Alexander S. Ledkov
Keyword(s):  
Space Debris ◽  
Ion Beam ◽  
Center Of Mass ◽  
Phase Portraits ◽  
Gravity Gradient ◽  
Attitude Motion ◽  
Cylindrical Shape ◽  
Contactless Method ◽  
Large Space ◽  
Ion Flow

The paper is devoted to the problem of space debris mitigation. Contactless method of the space debris deorbiting is considered. It is assumed that ion thrusters on the active spacecraft create the ion flow, which blows the debris and slows it down. The objectives of this work are the development of mathematical models and the research of space debris motion under the action of the ion flow. It is supposed that the space debris is a rigid body of a cylindrical shape. Calculation of ion beam force and torque was performed for a self-similar model of plasma plume expansion using the hypothesis of ion fully diffused reflection from a surface. A mathematical model describing plane motions of the cylindrical space debris under the influence of gravity gradient torque and the ion flux was constructed. It was shown that motion of the space debris around its center of mass has a significant effect on its removal time. Phase portraits, describing the motion of the space debris relative to its center of mass, were constructed. Comparison of the descent times in different motion modes was carried out. The results can be used to create new effective systems of large space debris removal.

scholarly journals Defunct Satellites in Nearly Polar Orbits: Long-term Evolution of Attitude Motion

2018 ◽  
Vol 27 (1) ◽  
pp. 264-277 ◽  
Author(s):  
Dmitry Pritykin ◽  
Sergey Efimov ◽  
Vladislav Sidorenko
Keyword(s):  
Space Debris ◽  
Eddy Currents ◽  
Intermediate Phase ◽  
Gravity Gradient ◽  
Attitude Motion ◽  
Attitude Dynamics ◽  
Ellipsoid Of Revolution ◽  
Low Earth Orbits ◽  
High Space ◽  
Earth Orbits

Abstract Low Earth orbits (LEO) are known as a region of high space activity and, consequently, space debris highest density. Launcher upper stages and defunct satellites are the largest space debris objects, whose collisions can result in still greater pollution, rendering further space missions in LEO impossible. Thus, space debris remediation is necessary, and the LEO region is a primary target of active debris removal (ADR) projects. However, ADR planning requires at least an approximate idea of the candidate objects’ attitude dynamics, which is one of the incentives for our study. This paper is mainly focused on modeling and simulating the attitude dynamics of defunct satellites. We consider a “boxwing” configuration satellite with an ellipsoid of inertia close to an oblate ellipsoid of revolution. The dynamical model takes into account the gravity-gradient torque, the torque due to the residual magnetic moment, and the torque due to eddy currents induced by the interaction of conductive materials with the geomagnetic field. A better understanding of the intermediate phase of the exponential deceleration and existing final regimes is achieved owing to a more accurate model of the eddy-current torque than in most prior research.We also show the importance of orbital precession, which contributes to the overall attitude motion evolution.

Integrated Structural and Control Optimization

2004 ◽  
Vol 10 (10) ◽  
pp. 1377-1391 ◽  
Author(s):  
Ijar M. Fonseca ◽  
Peter M. Bainum
Keyword(s):  
Analytical Approach ◽  
Minimum Weight ◽  
Space Structure ◽  
Design Parameters ◽  
Gravity Gradient ◽  
Control Optimization ◽  
Design Variables ◽  
Analytical Derivatives ◽  
And Control ◽  
Derivatives Of

This paper focuses on the integrated structural/control optimization of a large space structure with a robot arm subject to the gravity-gradient torque through a semi-analytical approach. It is well known that the computer effort to compute numerically derivatives of the constraints with respect to design variables makes the process expensive and time-consuming. In this sense, a semi-analytical approach may represent a good alternative when optimizing systems that require sensitivity calculations with respect to design parameters. In this study, constraints from the structure and control disciplines are imposed on the optimization process with the aim of obtaining the structure’s minimum weight and the optimum control performance. In the process optimization, the sensitivity of the constraints is computed by a semi-analytical approach. This approach combines the use of analytical derivatives of the mass and stiffness matrices with the numerical solution of the eigenvalue problem to obtain the eigenvalue derivative with respect to the design variables. The analytical derivatives are easy to obtain since our space structure is a long one-dimensional beam-like spacecraft.

Sign in / Sign up

Export Citation Format

Share Document