Space subsystems design: (navigation, control, structure and…)
Arian Zakiani; Seyed Hassan Sedighy; Razieh Narimani
Volume 17, Issue 1 , March 2024, , Pages 73-79
Abstract
Due to the limited communication time between LEO satellites and the ground station and large volume of satellite image data, it is necessary to establish a high transmission rate connection. Therefore, the use of a high-efficiency satellite antenna is inevitable. In order to use the limited viewing ...
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Due to the limited communication time between LEO satellites and the ground station and large volume of satellite image data, it is necessary to establish a high transmission rate connection. Therefore, the use of a high-efficiency satellite antenna is inevitable. In order to use the limited viewing time of the satellite, it must be possible to communicate with the ground station at low angles and change the main beam direction of satellite antenna to the direction of the ground station. The proposed array is composed of 8 antenna elements with a compact microstrip feed network. Low profile structure, circular polarization, high gain and low cost specifications of this proposed antenna array, candidate it for conformal array antenna in satellite applications.
Space New Technologies
Pedram Hajipour; Roghieh Karimzadeh Baee; Houman Zarrabi; Roghayeh Doost; Leila Mohammadi
Volume 16, Issue 2 , June 2023, , Pages 27-42
Abstract
According to the technical specifications of the future generations of telecommunication (the fifth generation and later), which should provide new services with very high data rates in the minimum time and a wide coverage, as well as the exponential increase in traffic, the use of combined space-air ...
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According to the technical specifications of the future generations of telecommunication (the fifth generation and later), which should provide new services with very high data rates in the minimum time and a wide coverage, as well as the exponential increase in traffic, the use of combined space-air networks Land is essential. It should be noted that the management of this type of combined networks has major challenges in providing such services. Meanwhile, the intelligent management of resources in satellite-based hybrid networks will lead to increased capacity and improved service quality. For this purpose, in this article, a comprehensive review of the use of artificial intelligence in the field of satellite communications will be discussed. In the field of intelligent increase of capacity, various factors such as how to configure the network, how to allocate resources such as spectrum, energy and power will be investigated with consideration of intelligent interference management. Finally, in the field of service quality improvement, factors such as how to model and intelligently predict traffic, as well as how to deal with harmful environmental conditions, will be presented.
Space subsystems design: (navigation, control, structure and…)
M. Navabi; F. Malekpour
Volume 15, Issue 2 , June 2022, , Pages 15-25
Abstract
In the variable parameter linear method, which is used to express systems with time-varying state-space matrices, the stability and performance of the feedback system are guaranteed, and there is a significant potential for improving efficiency. The dynamics of these systems depend on a variable parameter ...
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In the variable parameter linear method, which is used to express systems with time-varying state-space matrices, the stability and performance of the feedback system are guaranteed, and there is a significant potential for improving efficiency. The dynamics of these systems depend on a variable parameter with time, considered in this research as the angular velocity of the reaction wheel. The values of this parameter are during an unknown period but can be measured by system performance. Using the tabulation gain technique, the stability of the variable parameter system is checked, and the tabulation parameter is selected for estimating practical control factors. The convex algorithm can solve the extracted sufficient conditions converted into linear matrix inequality conditions. By solving these controlling conditions, the tabulated gain is obtained to guarantee the stability and performance of the variable parameter system. Numerical simulation results show the success of the proposed method.
Space systems design (spacecraft, satellites, space stations and their equipment)
Hamed Alisadeghi; Azade Khadivi; Ehsan Zabihian
Volume 15, Issue 2 , June 2022, , Pages 43-58
Abstract
The interaction of thruster plumes with satellite components can have undesirable effects, such as disturbance force/torque, thermal loading, and species deposition in the surfaces. The purpose of this paper is to use the Direct Simulation Monte Carlo (DSMC) method to analyze the 3D plume impingement ...
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The interaction of thruster plumes with satellite components can have undesirable effects, such as disturbance force/torque, thermal loading, and species deposition in the surfaces. The purpose of this paper is to use the Direct Simulation Monte Carlo (DSMC) method to analyze the 3D plume impingement flows and investigate its effects. Two impingement problems are computed. The impact of a jet of nitrogen on an inclined flat plate is considered. Good agreement is found between surface quantities calculated by DSMC and experimental data. The plume of a hydrazine control thruster firing in a model satellite configuration is simulated. Surface quantities and net impingement effects are calculated. The effects of partial displacement of the thruster locations on the results have also been investigated. The results show that a 20% displacement of the thruster location can change the disturbance force/torque by up to 15% of the initial values.
Space systems design (spacecraft, satellites, space stations and their equipment)
Amirhossain Adami; Mehran Nosratollahi; Hanieh Eshagh nia; Sajjad Kheirkhah; Shiva Emami; Ali Saadat dar; Narges Afsari; Khashayar Mashhadi; Mansour Hozuri
Volume 13, Issue 2 , June 2020, , Pages 63-77
Abstract
The CANSAT design, a simple and small scale of a satellite, is an experience for preparing for the design of a Life cycle of the space project. In this paper, the process of design and construction of ARTA CanSat, which is participated in the scientific-exploratory class of international competition ...
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The CANSAT design, a simple and small scale of a satellite, is an experience for preparing for the design of a Life cycle of the space project. In this paper, the process of design and construction of ARTA CanSat, which is participated in the scientific-exploratory class of international competition in CANSAT Iran, has been written. The operation scenario is that an automatic scanner system, lands after releasing from 300 meters above ground level with using a recovery subsystem (parachute), which is controlled its downfall and landing position by the parachute controller system. During the descent, the data is transmitted by the sensors and sent to the ground station. After touchdown, the Hotwire system's operates and separates the parachute from the Rover section; Then CanSat with the moving on the ground by using the simpler section embedded underneath the structure, performing excavation while moving to the target point. Throughout the mission, the health of the biological payload is preserved.
Mehrdad Khosravi; Saeid Salehy; Mohsen Abedi
Volume 12, Issue 1 , April 2019, , Pages 55-68
Abstract
Decreasing satellite solar arrays temperature, results in increasing electrical efficiency. Efficiently and subsequently power generation enhancements have several advantages. One of the modern techniques for balancing temperature conditions is employing heat pipes. In the present paper, design optimization ...
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Decreasing satellite solar arrays temperature, results in increasing electrical efficiency. Efficiently and subsequently power generation enhancements have several advantages. One of the modern techniques for balancing temperature conditions is employing heat pipes. In the present paper, design optimization of heat pipes configuration attached to the solar arrays of a sun-pointing satellite is conducted using multiobjective genetic optimization algorithm. The objective of optimization is to reduce solar cells temperature and utilized heat pipes mass simultaneously. Thermal simulations of the satellite are carried out with SINDA/FLUINT and Thermal Desktop softwares. The numerical simulations are validated against experimental measurements of the satellite thermal model in a vacuum chamber. Afterwards, the multiobjective genetic algorithm produced the optimal configurations of the heat pipes using the optimal Pareto concept. Six different designs on the Pareto front are selected and their corresponding results are discussed.
Behzad Mohasel afshari; Javad Haghshenas; Mohsen Abedi; Masoud Khoshsima
Volume 11, Issue 4 , December 2018, , Pages 23-30
Abstract
In this paper, a precise method for calculating albedo and IR heat flux applied to a satellite is presented. For obtaining albedo heat flux applied to a satellite, a point on the earth’s surface that sun flux reflected at that point and reach to the satellite is obtained, hence albedo heat flux ...
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In this paper, a precise method for calculating albedo and IR heat flux applied to a satellite is presented. For obtaining albedo heat flux applied to a satellite, a point on the earth’s surface that sun flux reflected at that point and reach to the satellite is obtained, hence albedo heat flux reaches to a satellite is obtained as a function of longitude, attitude and longitude. IR heat flux is integration of emitting heat flux for points on the earth surface that in satellite’s view. Atmospheric transparency for calculating albedo and IR heat is considered for sun light and IR spectrum using MODTRAN algorithm using PcModWin software. For a generic LEO satellite, IR and albedo heat fluxes are calculated at a time period and compare with reference values. Obtained heat fluxes are used to obtain temperature variation of satellite’s components during its mission.
ehsan maani; Hossein Nejat Pishkenari; Amir Reza Kosari
Volume 11, Issue 3 , December 2018, , Pages 63-71
Abstract
In this paper, the combination of reaction wheels and thrusters is applied to attitude control of a satellite. First, governing equations of satellite attitude dynamics are given using quaternion and PID controller is designed based on the satellite quaternion to determine the applied control torque. ...
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In this paper, the combination of reaction wheels and thrusters is applied to attitude control of a satellite. First, governing equations of satellite attitude dynamics are given using quaternion and PID controller is designed based on the satellite quaternion to determine the applied control torque. By applying the reaction wheels physical constraints such as its maximum torque, its maximum momentum and maximum power on the desired torque, reaction wheels angular momentums and torques are found. The obtained results show that the unsaturated reaction wheels capabilities in attitude control. Results also show that the wheels saturation leads to error in control and increases the Euler angles and quaternions. Satellite thrusters are utilized to reaction wheels de-saturation and attitude control simultaneously.Three different strategies are proposed in this paper for wheels de-saturation using thrusters. Two well known methods, pulse width modulator (PWM) and pulse width pulse frequency (PWPF) modulator are used to attitude control using thrusters. All methods are compared together and the optimal method is proposed for the satellite attitude control. This paper results can be useful in design and control of different class of satellites.
Farhad Fani Saberi; Mansor Kabganian; Alireza Fazlyab; Abbas Ajorkar
Volume 9, Issue 1 , May 2016, , Pages 25-35
Abstract
In this paper, a robust attitude control algorithm is developed based on backstepping-sliding mode control for a satellite using four reaction wheels in a tetrahedron configuration. In this method, asymptotic stability of the proposed algorithm has been proven in the presence of reaction wheels dynamic ...
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In this paper, a robust attitude control algorithm is developed based on backstepping-sliding mode control for a satellite using four reaction wheels in a tetrahedron configuration. In this method, asymptotic stability of the proposed algorithm has been proven in the presence of reaction wheels dynamic model based on Lyapunov theory. Then, in order to evaluate the performance of the proposed algorithm, a low-cost real-time prossecor in the loop test bed is provided. The presented test bed is capable of real-time assessing the attitude backstepping-sliding mode control algorithm. In this test bed, real-time modeling of satellite dynamic, environmental disturbances and reaction wheels are achieved in a simulator computer and the proposed control algorithm performance is investigated by implementing it in an electronic control board of the prossecor in the loop test bed.
Zahra Samadi Khoshkho; Mehdi Mortazavi-Bek; Farhad Fani Saberi
Volume 9, Issue 1 , May 2016, , Pages 47-56
Abstract
In this paper, an adaptive controller based on decentralized minimal control synthesis is designed n order to control an attitude of specific remote sensing satellite. The main design purposes are performing spinning, three axis and large angle maneuver as well as achieving a stable system and tracking ...
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In this paper, an adaptive controller based on decentralized minimal control synthesis is designed n order to control an attitude of specific remote sensing satellite. The main design purposes are performing spinning, three axis and large angle maneuver as well as achieving a stable system and tracking the reference attitude trajectory in the presence of uncertainties. In the design process, the effects of internal and external disturbances, nonlinearities in the satellite dynamic and the accurate model of actuators are regarded. Four reaction wheels with pyramidal structure are modeled as the actuators to accomplish an attitude maneuver. So the exact reaction wheels’ model with regarding the maximum voltage, current, allowable angular velocities and power of wheels is developed. The simulation results show an acceptable performance of controller in the presence of exacts actuators’ model, external and internal disturbances and uncertainties in the satellite parameters.
Ali Mehrabi; Fathallah Ommi
Volume 9, Issue 1 , May 2016, , Pages 59-72
Abstract
In this paper, an adaptive controller based on decentralized minimal control synthesis is designed n order to control an attitude of specific remote sensing satellite. The main design purposes are performing spinning, three axis and large angle maneuver as well as achieving a stable system and tracking ...
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In this paper, an adaptive controller based on decentralized minimal control synthesis is designed n order to control an attitude of specific remote sensing satellite. The main design purposes are performing spinning, three axis and large angle maneuver as well as achieving a stable system and tracking the reference attitude trajectory in the presence of uncertainties. In the design process, the effects of internal and external disturbances, nonlinearities in the satellite dynamic and the accurate model of actuators are regarded. Four reaction wheels with pyramidal structure are modeled as the actuators to accomplish an attitude maneuver. So the exact reaction wheels’ model with regarding the maximum voltage, current, allowable angular velocities and power of wheels is developed. The simulation results show an acceptable performance of controller in the presence of exacts actuators’ model, external and internal disturbances and uncertainties in the satellite parameters.
Farhd Fani Saberi
Volume 8, Issue 3 , October 2015, , Pages 15-26
Abstract
In this paper, achieving of Stereo-Imaging scenario by a remote sensing satellite will be presented. Then a suitable attitude control system will be designed using 4 reaction wheels with pyramidal structure to fulfill large angle maneuvers of stereo-imaging scenario. The proposed attitude control system ...
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In this paper, achieving of Stereo-Imaging scenario by a remote sensing satellite will be presented. Then a suitable attitude control system will be designed using 4 reaction wheels with pyramidal structure to fulfill large angle maneuvers of stereo-imaging scenario. The proposed attitude control system provide the satellite with the capability of nadir pointing and large angle maneuvers to take different images of a predefined zone from different point of view. In order to verify the performance of the designed attitude control system, a low-cost real time hardware in the loop test bed will be constructed. The constructed test bed is capable of assessing attitude control algorithms in a real time conditions. In the proposed test bed, accurate and real time modeling of satellite dynamics, space conditions, reaction wheels and gyroscopes will be done by the Simulator computer. Finally, performance of the designed attitude controller to achieve stereo-imaging scenario is investigated by implementing the algorithm in the hardware in the loop test bed in a real time condition.
Hamed R. Najafi; Esmaiel Moeini; Seyed Mohammad Hossein Karimian; Hamed Alisadeghi
Volume 8, Issue 1 , April 2015, , Pages 19-25
Abstract
The intention of this paper is to discuss the results obtained from tests conducted at Amirkabir University of Technology Thermal Control Lab on multilayer insulation (MLI) blankets designed and fabricated in university, describing the thermal performance of test specimens at different environmental ...
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The intention of this paper is to discuss the results obtained from tests conducted at Amirkabir University of Technology Thermal Control Lab on multilayer insulation (MLI) blankets designed and fabricated in university, describing the thermal performance of test specimens at different environmental temperatures. We have evaluated the MLI performance by experimentally measuring our MLI’s emissivity factor. For this purpose we have defined our experiments based on the effective emissivity model. Fabricated MLI blankets are tested in a vacuum chamber at an approximate pressure of 10-6mbar and temperatures of approximately 30°C and -70°C, while subjected to heat with the power input in the range of 1.0 to 2.5 Watts. Results show that the measured effective emissivity is within the range of other reported experimental data.
Kamal Jahani; Hossein Farajollahi
Volume 7, Issue 4 , January 2015, , Pages 81-91
Abstract
During launching and deploying to orbit, satellites experience vibration loads from launch vehicle especially in longitudinal direction. Even though the aim of the adapter between satellite and launcher is to isolate the satellite from the launcher's dynamic loads, however, still enough harsh vibration ...
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During launching and deploying to orbit, satellites experience vibration loads from launch vehicle especially in longitudinal direction. Even though the aim of the adapter between satellite and launcher is to isolate the satellite from the launcher's dynamic loads, however, still enough harsh vibration loads that can affect the operation of satellite's delicate systems transmit to the structure of the satellite. Therefore, there is need to isolate the delicate systems from vibrations of the satellite's structure. In this paper, the performance of a new material namely Silicone Gel in isolating delicate equipments (such as electronic board and its components) of satellite from longitudinal vibrations is investigated using finite element method. The results of modeling of an isolator containing Silicone Gel are verified by the available experimental results from the literature. Besides having frequency dependent behavior and dissipation characteristic, Silicone Gel shows hyper-elastic behavior that these characteristic are considered in modeling and analysis. Also an electronic board that overlays on Silicon Gel type mounts is modeled and the amount of transmitted vibration to lead wire of a resistor on it is investigated. The obtained results show that the Silicone Gel has good performance in isolating of delicate equipments of satellite from incoming longitudinal vibrations.Â
A. Chekini; H. R. Naji
Volume 7, Issue 1 , April 2014, , Pages 57-66
Abstract
This paper presents the design procedure and implementation results of a proposed hardware which performs different satellite Image compressions using FPGA Xilinx board. First, the method is described and then VHDL code is written and synthesized by ISE software of Xilinx Company. The results show that ...
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This paper presents the design procedure and implementation results of a proposed hardware which performs different satellite Image compressions using FPGA Xilinx board. First, the method is described and then VHDL code is written and synthesized by ISE software of Xilinx Company. The results show that it is easy and useful to design, develop and implement the hardware image compressor using new techniques of programmable logic tools for space applications. In this paper the proposed hardware uses the proposed hardware, and it is put on board of satellite. Appropriate bit streams are produced by synthesis tools; therefore, we have two bit streams which can be configured at any moment of time according to the user request. When users intend the hardware is reconfigured and changed from JPEG to JPEG2000 or vice versa. The Proposed architecture has some advantages other than previous architectures such as high-speed and real-time processing, high flexibility, low cost, high security and low power consumption. This idea can be utilized in modern commercial hardware space board for data compressing due to using partial reconfiguration technique.
M. S. Mohammadi; M. Mortazavi; M. Malekan
Volume 6, Issue 4 , January 2014, , Pages 43-52
Abstract
According to mission requirements in many of space missions, an exact time should be assigned for launch date namely launch window. Among various parameters influencing launch window, in this article a couple of most mission related ones are being researched. First is some constraints on handling satellite ...
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According to mission requirements in many of space missions, an exact time should be assigned for launch date namely launch window. Among various parameters influencing launch window, in this article a couple of most mission related ones are being researched. First is some constraints on handling satellite power and the second is the imaging mission constraintsfor a remote sensing satellite. Then after this study on mission requirements a conceptual method for launch window estimation is presented and supported by a case study on sample micro-satellite IRSAT.
H. Bolandi; M. H. Ashtari; M. Esmaeilzadeh; M. Haghparast
Volume 6, Issue 3 , October 2013, , Pages 27-37
Abstract
In this paper predicting of position of satellite based on extended kalman filter with considering hardware implementation consideration and simultaneously maintaining desired accuracy is investigated. For this purpose, first, effective forces on orbital dynamic and nonlinear equation of orbital motion ...
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In this paper predicting of position of satellite based on extended kalman filter with considering hardware implementation consideration and simultaneously maintaining desired accuracy is investigated. For this purpose, first, effective forces on orbital dynamic and nonlinear equation of orbital motion are presented. In order to increasing accuracy of prediction in position of satellite, J2, J3 and J4 harmonics of potentialfunction of the earth are considered and future position of satellite is predicted using linearized dynamic model and applying EKF on this model. Here Measurement data are position and velocity vector of satellite which are extracted by GPS receivers. Since in this paper systematic satellite design is considered, scenario of “ON TIME” of GPS receivers based on power consumption considerations is discussed. Finally simulation results for a LEO satellite and comparing these results with STK results, shows accuracy of presented modeling and equations.
Farhad Fani Saberi; Amir Eslami Mehrjardi
Volume 5, Issue 4 , January 2013, , Pages 39-45
Abstract
In this paper we are going to design an attitude control system for a Stereo-Imaging Remote Sensing Satellite using of four pyramidal reaction wheels. In this method, in order to provide the power requirements of the satellite by the energy stored in the reaction wheels, a power management law will be ...
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In this paper we are going to design an attitude control system for a Stereo-Imaging Remote Sensing Satellite using of four pyramidal reaction wheels. In this method, in order to provide the power requirements of the satellite by the energy stored in the reaction wheels, a power management law will be designed and added to the attitude control law to charge and discharge the wheels according to the preset profiles. Therefore, attitude control and power management of the satellite will be carried out simultaneously. In this method, while the satellite is in the light and the batteries are charged, the speed of the wheels increase up to the limited speeds and while the power requirements of the subsystems are inadequate, Power will be returned to the subsystems by reducing the speed of the wheels. The design of this system has been conducted to consider the effects of saturation of the wheels to prevent attitude deviations of satellite while power management is done. Simulation results show the good performance of the designed attitude control and power management system of the satellite.
Atefe Ajami; Siyamak Naseri; Davood Hashemi; Mahboube Arabsorkhi
Volume 5, Issue 3 , October 2012, , Pages 41-48
Abstract
In this paper, in order to separate images in four spectral bands (from blue to near infrared) in multispectral cameras, four-color separation prism advantagesarereviewed. Then, while description of ray tracing of four-color separation prism, main design parameters and principlesarementioned.After that, ...
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In this paper, in order to separate images in four spectral bands (from blue to near infrared) in multispectral cameras, four-color separation prism advantagesarereviewed. Then, while description of ray tracing of four-color separation prism, main design parameters and principlesarementioned.After that, design of a four-color separation prism model that attached to detector (CCD) by using the Zemaxsoftwarearedescribed,also spot diagrams,ray tracingand aberration graphsare analyzed. Finally, while expression four-color separation prism characteristics that yield fromprogramming with Zemax software, including weight, length of the optical path and thickness of equivalent blade, itsspecifications in remote sensing satellite multispectral camerasareexplained
E. Shafiee-Nejhad; N. Rahbar; M. Asghari; A. R. Novinzade
Volume 2, Issue 1 , April 2009, , Pages 59-65
Abstract
In this article the simulation of explosion and diffusion of debris consequent on explosion, in the space are studied. This method is simulated by the introduced code and the results are closely checked in accordance with different operational situations for the huge amounts of particles in different ...
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In this article the simulation of explosion and diffusion of debris consequent on explosion, in the space are studied. This method is simulated by the introduced code and the results are closely checked in accordance with different operational situations for the huge amounts of particles in different kinds of strategic orbits. Finally, the density distribution of debris that located in the same orbit is studied. The simulation examines the status of diffusion, trace settlement and also their location in orbits around the earth, during times that is wanted by user. Whatever satellite designing is immaculate, the satellite subsystems (such as batteries, propeller parts and etc) explosion and failing is possible, also smashing with the space masses is foreseeable. Regarding to the space orbits high expense and dedicating these orbits to each country; it is important to clean them from debris and necessary to understand this problem.
