space sciences and exploration
Farshad Somayehee; Amir Ali Nikkhah; Jafar Roshanian
Volume 14, Issue 2 , June 2021, , Pages 103-110
Abstract
In this paper, a new algorithm for determining the density of scattered data at the surface of the sphere is presented and then the proposed algorithm along with Geodesic Weighted K-Means clustering and Deluany triangulation are used to make uniform star catalogs. Comparison of the results with the results ...
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In this paper, a new algorithm for determining the density of scattered data at the surface of the sphere is presented and then the proposed algorithm along with Geodesic Weighted K-Means clustering and Deluany triangulation are used to make uniform star catalogs. Comparison of the results with the results of other related articles shows that the proposed algorithm resulted in a significant decrease in the probability of observing a large number of stars in all simulated star sensor fields of view. This improvement is due to the uniformity of the star catalog, especially in the celestial sphere poles due to the proposed density determination algorithm. On the other hand, the use of a proper data density algorithm has increased the likelihood of observing a few stars (such as 3 or 5) in all fields of view used in the Monte Carlo simulation.
communications
Pedram Hajipour; Hossein Eftekhari; Ali Kheirdoost; Hassan Yeganeh
Articles in Press, Accepted Manuscript, Available Online from 03 March 2024
Abstract
Satellite constellations include a set of similar satellites that are distributed in a specific orbital pattern to accomplish a common mission. Satellite constellations are commonly used to accomplish missions such as global telecommunications, global positioning, and remote sensing. In this article, ...
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Satellite constellations include a set of similar satellites that are distributed in a specific orbital pattern to accomplish a common mission. Satellite constellations are commonly used to accomplish missions such as global telecommunications, global positioning, and remote sensing. In this article, by using scientometric approach, the structure and scientific maps of the field of "satellite constellations" in the world, as well as two leading countries, including the United States and China, have been analyzed based on research documents published in this field. In addition, a comparison has been made between these two countries with the world. The research community includes all scientific documents in the field of "satellite constellations" that have been indexed in the "Scopus" database between 1969 and 2023 AD. Also, in this article, knowledge maps (thematic subfields) and international cooperation maps of countries have been drawn using Bibexcel and VOSViewer software.
Space subsystems design: (navigation, control, structure and…)
Milad َAzimi
Articles in Press, Accepted Manuscript, Available Online from 07 April 2022
Abstract
This paper deals with semi-analytical modeling and stability analysis of a coupled slosh-tank dynamics as a multibody system using the Homotopy Perturbation Method (HPM). The sloshing motion of the liquid inside the tank is considered as the equivalent pendulum model. The nonlinear equations of the motion ...
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This paper deals with semi-analytical modeling and stability analysis of a coupled slosh-tank dynamics as a multibody system using the Homotopy Perturbation Method (HPM). The sloshing motion of the liquid inside the tank is considered as the equivalent pendulum model. The nonlinear equations of the motion under lateral and longitudinal excitations (compressive oscillations) are derived using the Lagrangian approach. In this model, the effects of essential parameters such as viscous damping, amplitude, and frequency of the excitation are studied for two typical points inside and outside the stability regions. It has been shown that viscous damping, compared to other principle parameters, brings the points located in the unstable region closer to the stable region. The simulations in terms of stability diagrams, phase portraits, and time histories of sloshing amplitude are achieved using HPM and compared to the numerical Runge-Kutta method to follow the stability phenomena and highlight the analytical approach's validity.
Space New Technologies
Reza Amjadifard; Ehsan Mousivand; Farhad Bagheroskuee; Shahab Karbasian; Ehsan Kosari
Articles in Press, Accepted Manuscript, Available Online from 09 April 2024
Abstract
The prioritization and verification of space emerging technologies is a multi-step, iterative process that needs to collective intelligence (the participation of all stakeholders), as well as the use of analytical methods to identify requirements. This process begins with identifying specialists who ...
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The prioritization and verification of space emerging technologies is a multi-step, iterative process that needs to collective intelligence (the participation of all stakeholders), as well as the use of analytical methods to identify requirements. This process begins with identifying specialists who have enough knowledge and experience regarding to each technology, and followed by extracting and evaluating the necessary data, prioritizing technology options, identifying challenging technologies and the essential acquisition strategy, and finally prioritizing them. In this article, we implemented a method to identify and prioritize some space technologies which could be used in the electrical power subsystem (EPS) of a satellite. Based on the results, it would be possible to choose the best method to access the required technology; national development or benefiting of available technology in the market. To evaluate the suggested method, the power subsystem components are divided into three categories: electrical power generation sources, energy storage sources, and power electronic circuits. Applying the proposed method shows that the selected technologies are those is recently used in space. This method can also be applied to other subsystems.
Space subsystems design: (navigation, control, structure and…)
Moslem Karim Abadeh; Morteza Tayefi
Articles in Press, Accepted Manuscript, Available Online from 09 April 2024
Abstract
In this study, the control of a space capsule during the re-entry phase is examined. Re-entry is one of the most important phases of a spacecraft's mission because when the spacecraft enters the Earth's atmosphere, aerodynamic forces and moments will disturb the angles of attack and side slip. These ...
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In this study, the control of a space capsule during the re-entry phase is examined. Re-entry is one of the most important phases of a spacecraft's mission because when the spacecraft enters the Earth's atmosphere, aerodynamic forces and moments will disturb the angles of attack and side slip. These disturb angles, if not controlled, can cause serious injuries to the spacecraft and its passengers. To eliminate the disturbances, moving mass controllers have been used as an operator. Moving mass controllers (MMC) control the flying device by creating an internal force. The main advantage of moving mass controllers compared to other operators such as aerodynamic surfaces and thrust jets is the non-production of turbulent aerodynamic force (which can disrupt the controller's performance) due to the creation of internal force. Another important factor is the mechanism of moving mass controllers. In this research, in addition to the cross mechanism, which is a more common mechanism, the radial mechanism has also been examined. A non-linear controller is needed in order to use the radial mechanism, and in this research, a non-linear proportional-integral-derivative controller is suggested.
Space systems design (spacecraft, satellites, space stations and their equipment)
Amirhossain Adami; zahra pourJabari; Mohammad azhdari; Ali Saadat dar; Hanieh Eshaghnia; Kazem gholipour; seyedmohammad mirmohammadi; Alireza Ahangarani Farahani
Articles in Press, Accepted Manuscript, Available Online from 21 April 2024
Abstract
In this research, the structure of the probes sent to other planets is first investigated and the common structures are introduced. In the following, the system design process of the Armita probe, which was prepared for the first national competition of the probe robot (Iran Space Research Institute), ...
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In this research, the structure of the probes sent to other planets is first investigated and the common structures are introduced. In the following, the system design process of the Armita probe, which was prepared for the first national competition of the probe robot (Iran Space Research Institute), will be discussed. Armita team has won the first place in the first phase of the competition in 1401. The probe design process is based on the ECSS standard and is presented briefly, which includes the compilation and extraction of the requirements document, function-performance tree, product tree and finally the conceptual design of the sub-systems to achieve the intended mission. Based on the extracted results, the Armita probe with a mass of 6.9 kg and geometric dimensions of 48 x 38 x 36 cm with a total energy consumption of 112 amp hours will be able to perform the intended mission and satisfy all technical, dimensional and mass requirements well. shows
