Orbit
Mostrando 13-24 de 421 artigos, teses e dissertações.
-
13. Optimizing the Communication Capacity of a Ground Station Network
ABSTRACT: Small satellites are growing in use for educational, scientific, and commercial purposes, usually in Low Earth Orbit (LEO) flights, given their lower costs and associated risks, as well as smaller lead times for assembling and testing. However, the typically short periods of LEO passes bring the need to find ways of optimizing the communication bet
J. Aerosp. Technol. Manag.. Publicado em: 09/05/2019
-
14. Satellite Inertia Parameters Estimation Based on Extended Kalman Filter
ABSTRACT: The moment of inertia parameters play a critical role in assuring the spacecraft mission throughout its lifetime. However, determination of the moment of inertia is a key challenge in operating satellites. During satellite mission, those parameters can change in orbit for many reasons such as sloshing, fuel consumption, etc. Therefore, the inertia
J. Aerosp. Technol. Manag.. Publicado em: 28/03/2019
-
15. Thermal Analysis of Satellite Libertad 2: a Guide to CubeSat Temperature Prediction
ABSTRACT: We present a model for predicting the temperature of three-unit CubeSat on a low Earth orbit, which supposes a single temperature common to all satellite components. Our exposition includes a detailed, to a large extent analytical, computation of the external heat fluxes for a particular orbit and spacecraft assumptions based on the features forese
J. Aerosp. Technol. Manag.. Publicado em: 08/11/2018
-
16. Research on the Folding Patterns and Deployment Dynamics of Inflatable Capsule Structures
ABSTRACT: The folding patterns and deployment dynamic characteristics of conical inflatable capsule structures were investigated. A six-fold-line method of packing a conical shell surface was designed. The fold-line layouts and relation formulas of the fold angles were determined. The folded state of the inflatable capsule structure was parametrically modele
J. Aerosp. Technol. Manag.. Publicado em: 08/11/2018
-
17. Multi-objective Optimization Method For Repeat Ground-track Orbit Design Considering the Orbit Injection Error
ABSTRACT: Considering the adverse effects of orbit injection error, a novel repeat ground-track orbit redesign approach is proposed to reduce the fuel consumption caused by the orbital maneuvering from the injection orbit to the nominal orbit. By introducing the performance indexes of revisiting accuracy and orbit injection maneuvering fuel consumption, the
J. Aerosp. Technol. Manag.. Publicado em: 07/06/2018
-
18. Simulation of Active Eye Motion Using Finite Element Modelling
Abstract Dynamic simulation of human eye movements can significantly improve our understanding about the visuomotor system and also may be used for clinical applications. In this study we have developed a 3D finite element model of the eye orbit. The major novel issues which are considered in this work are using dynamic finite element method for properly ma
Lat. Am. j. solids struct.. Publicado em: 14/05/2018
-
19. Analytical Solution for Optimal Low-Thrust Limited-Power Transfers Between Non-Coplanar Coaxial Orbits
ABSTRACT: In this paper, an analytical solution for time-fixed optimal low-thrust limited-power transfers (no rendezvous) between elliptic coaxial non-coplanar orbits in an inverse-square force field is presented. Two particular classes of maneuvers are related to such transfers: maneuvers with change in the inclination of the orbital plane and maneuvers wit
J. Aerosp. Technol. Manag.. Publicado em: 03/05/2018
-
20. Investigating Space Radiation Environment Effects on Communication of Razaksat-1
ABSTRACT: This study attempted to identify whether space radiation sources could have affected the communication on RazakSAT-1 that was orbiting in a Low Earth Orbit-Near Equatorial (LEO-NEqO). Data on galactic cosmic rays (GCR), trapped protons, trapped electrons, and solar energetic particles (SEPs) obtained from Space Environment Information System (SPENV
J. Aerosp. Technol. Manag.. Publicado em: 03/05/2018
-
21. Design and Analysis of a Novel Spacecraft for Mitigating Global Warming
ABSTRACT: A device called Huge Space Shield (HSS) has been put forward for mitigating global warming. This is a space tethers system, which use cables to connect a shielding surface and a mechanism control. In this study, orbital analysis was carried out to choose the best orbit for getting the best effect. Simulation studies were employed to understand the
J. Aerosp. Technol. Manag.. Publicado em: 26/02/2018
-
22. Space Propulsion: a Survey Study About Current and Future Technologies
ABSTRACT: Current Space Launch Vehicles use chemical reactions (solid and liquid propellants) to achieve sufficient thrust to launch artifacts and humans into space. Propulsion technologies can be framed in three different categories: "escape propulsion", "in-space propulsion", and "deep space propulsion". The launch vehicles currently used for "escape propu
J. Aerosp. Technol. Manag.. Publicado em: 26/02/2018
-
23. Application of a Bibliometric Tool for Studying Space Technology Trends
ABSTRACT: The statistical analysis of academic literature, also known as “bibliometrics”, is being increasingly applied to analyse research trends, to identify emerging areas of science and to find out where and how often specific articles are cited. The aim of this study was to identify technological innovation trend patterns in the aerospace sector app
J. Aerosp. Technol. Manag.. Publicado em: 15/02/2018
-
24. COMPARATIVE ASSESSMENT BETWEEN PER-PIXEL AND OBJECT-ORIENTED FOR MAPPING LAND COVER AND USE
ABSTRACT: The traditional per-pixel classification methods consider only spectral information, and may be limited. Object-based classifiers, however, also consider shape and texture, firstly segmenting the image, and then classifying individual objects. Thus, a Geographic Object-Based Image Analysis (GEOBIA) was compared in conjunction with data mining techn
Eng. Agríc.. Publicado em: 2017-09