Research Paper
Space systems design (spacecraft, satellites, space stations and their equipment)
Amirreza Kosari; Asad Saghari; Masoud Khoshsima
Volume 14, Issue 4 , December 2021, Pages 1-9
Abstract
This article investigates an operational orbit's design and sensitivity analysis for Earth observation (EO) missions in non-sun-synchronous orbits. Sun-synchronous orbits are the primary choice for deploying EO satellites, but in the absence of access to such orbits, alternative options can be considered, ...
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This article investigates an operational orbit's design and sensitivity analysis for Earth observation (EO) missions in non-sun-synchronous orbits. Sun-synchronous orbits are the primary choice for deploying EO satellites, but in the absence of access to such orbits, alternative options can be considered, including multi-sun-synchronous orbits (MSSO) capable of repeating ground track (RGT).In this research, sets of such orbits are designed, taking into account the defined mission and considering the available altitude and inclination of the orbit. To achieve this, a constrained search problem is formulated, considering the constraints related to the characteristics of multi-sun-synchronicity and repeating ground tracks to search for orbit characteristics.Furthermore, to identify the allowable range of injection errors, a sensitivity analysis of the designed orbit's characteristics has been conducted to assess their sensitivity to uncertainties in injection accuracy during a case study investigation.
Research Paper
investigating space radiation
Hamideh Daneshvar; Azam Eidi; Leila Mohamadi; Reza Omidi; Pedram Hajipour
Volume 14, Issue 4 , December 2021, Pages 11-23
Abstract
Space radiation can affect the performance and reliability of components in space systems. This paper focuses on the investigation of three types of radiation damage including ionizing dose, displacement damage, and single event damage using OMERE software. Considering the outputs of this software, how ...
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Space radiation can affect the performance and reliability of components in space systems. This paper focuses on the investigation of three types of radiation damage including ionizing dose, displacement damage, and single event damage using OMERE software. Considering the outputs of this software, how to use and use a variety of electronic components with different commercial, military and space grades in LEO and GEO satellites is discussed. These components have the least risk of displacement damage. Mass budget constraints should also be considered when using commercial components in the GEO circuit. The maximum thickness for the safety of components in LEO and GEO circuits is 2.6 mm and 9.5 mm respectively. Given the inability of SEE damage to increase in thickness, the best solution to this damage is to use radiation-resistant solutions, especially software issues.
Research Paper
Space systems design (spacecraft, satellites, space stations and their equipment)
Mostafa Jafarpanah; Hassan Naseh
Volume 14, Issue 4 , December 2021, Pages 25-33
Abstract
The purpose of this paper is to present the cost estimation model for Cryogenic/Semi-Crogenic space propulsion systems. Therefore, the space propulsion system selection from fuel and oxidizer type aspect and achieving the maximum performance and minimum cost has been performed. Then, the fuel and oxidizer ...
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The purpose of this paper is to present the cost estimation model for Cryogenic/Semi-Crogenic space propulsion systems. Therefore, the space propulsion system selection from fuel and oxidizer type aspect and achieving the maximum performance and minimum cost has been performed. Then, the fuel and oxidizer pair samples based on the mass – energy specifications (engine weight- specific impulse) and engine operation cycle type with respect to the mission possibility has been determined. To this end, the algorithm for implementing and using the proposed cost estimation model has been designed. In this algorithm, the proposed cost estimation model is developed based on the existing cost estimation relationship and verified by comparing the existing models. Finally, the outputs in the algorithm are cost-performance (specific impulse) graph for the seven fuels and oxidizer pairwise, engine selection based on achieving maximum specific impulse and providing the design space searches for the cost and time optimization in the space projects.
Research Paper
Space systems design (spacecraft, satellites, space stations and their equipment)
Hanieh Eshaghnia; Mehran Nosratollahi; Amirhossain Adami
Volume 14, Issue 4 , December 2021, Pages 35-49
Abstract
A new approach to the design and development of launchers is the use of advanced technologies to reduce design and development costs as much as possible. In this paper, an approach to reduce costs and increase reliability is proposed, which is based on the use of a non-turbo pump propulsion system (pressure-fed ...
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A new approach to the design and development of launchers is the use of advanced technologies to reduce design and development costs as much as possible. In this paper, an approach to reduce costs and increase reliability is proposed, which is based on the use of a non-turbo pump propulsion system (pressure-fed propulsion system) instead of a turbo pump propulsion system. For this purpose, the multidisciplinary conceptual design optimization of a two-stage launch vehicle with a pressure-fed propulsion system with the aim of sending max payload with a least gross mass to the orbit (500 km) in terms of structure, aerodynamics, propulsion, pressure vessels, simulation, and pitch program disciplines. Then, the sensitivity analysis was performed on the optimum launcher to determine the efficiency of the launcher at different orbital heights and the ability to carry a suitable payload.
Research Paper
Space subsystems design: (navigation, control, structure and…)
Reza Sheikhbahaei; Saeed Khankalantary
Volume 14, Issue 4 , December 2021, Pages 51-59
Abstract
In this study, on the basis of proportional navigation strategy, design of explicit optimal guidance law for missiles tracking maneuvering targets in three-dimensional space using model predictive control is addressed. The model predictive control employs a model to predict the future process behavior ...
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In this study, on the basis of proportional navigation strategy, design of explicit optimal guidance law for missiles tracking maneuvering targets in three-dimensional space using model predictive control is addressed. The model predictive control employs a model to predict the future process behavior and calculates an optimal control input at each time step through the optimization of an objective function. Generalized model predictive control approach, employed in this study, solves the optimization problem offline to obtain the closed form optimal control law. In this paper, firstly, the equations describing the missile-target relative motion kinematics are formulated. Then, the optimal control law, as an explicit function of the state vector is obtained. The evaluation of the proposed scheme is studied by the comparison of the simulation results with the augmented proportional navigation system. Simulation studies, in three different scenarios, demonstrates appropriate performance for the proposed guidance system specially against maneuvering targets.
Research Paper
physiology and space medicine (astrobiology)
Zahra Hajebrahimi; Maryam Salavatifar
Volume 14, Issue 4 , December 2021, Pages 61-66
Abstract
Studies have shown that simulated microgravity (SMG) affects tumor cell growth and metastasis. However, the underlying molecular basis is still not known. In recent years, due to the high expression of CD44 in invasive basal breast tumors, it has been the subject of many studies. The aim of present study ...
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Studies have shown that simulated microgravity (SMG) affects tumor cell growth and metastasis. However, the underlying molecular basis is still not known. In recent years, due to the high expression of CD44 in invasive basal breast tumors, it has been the subject of many studies. The aim of present study was to investigate the gene expression of CD44 in MDA-MB-231cell line of breast cancer in microgravity conditioncell line was proliferated under normal gravity and microgravity (1 and 3 days) using 2-D clinostat. Gene expression was measured using real-time PCR technique. SMG increased gene expression (100%) after 1 day and decreased it (15%) during 3 days in comparison to the control samples. It seems that the response of cancer cells to microgravity is time dependent and simulated microgravity treatment for 3 days may have a positive effect on cancer characteristics of MDA-MB-231 cell line in order to decrease the expression of CD44.
Research Paper
commerce, management, and apace law
Mahdi Gholami
Volume 14, Issue 4 , December 2021, Pages 67-76
Abstract
This paper examines the funding sources of space industry. First, an overview of the space economy and investment flows in the industry is presented. Long-run trends indicate an increase in public and private investment in the space industry. Government funding is the most important source of funding ...
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This paper examines the funding sources of space industry. First, an overview of the space economy and investment flows in the industry is presented. Long-run trends indicate an increase in public and private investment in the space industry. Government funding is the most important source of funding for space programs. Also, the international cooperations in this industry has played a significant role in the development path of space activities. On the other hand, more applications in the services and other economic sectors has increased the entry incentives for private investors. Therefore, financing space projects through private funds is also one of the growing trends in the space industry. The findings show that the shift of governments from construction investments to commercialization investments. In contrast, the increasing application of space activities and the digitalization pattern of the industry have paved the way for micro-actors to enter with less financial resources.
Research Paper
Space subsystems design: (navigation, control, structure and…)
M. Navabi; P. Zarei
Volume 14, Issue 4 , December 2021, Pages 77-83
Abstract
The use of four reaction wheels to control the three-axis attitude of the spacecraft, considering its mechanical performance and the possibility of its failure, is a practical solution in the face of a defect in one of the wheels. In this article, the optimal control of the spacecraft, which has four ...
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The use of four reaction wheels to control the three-axis attitude of the spacecraft, considering its mechanical performance and the possibility of its failure, is a practical solution in the face of a defect in one of the wheels. In this article, the optimal control of the spacecraft, which has four reaction wheels, is investigated. Controlling the attitude of a spacecraft with just two reaction wheels is a significant issue that conventional controllers are not able to do. Therefore, the use of nonlinear model-based predictive controller is used to control the attitude of this spacecraft and compared with optimal nonlinear control in a discrete-time comparison, which satisfies the acceptable results.
Research Paper
Space systems design (spacecraft, satellites, space stations and their equipment)
Hojat Taei; Amirhossain Adami; Mansour Hozuri
Volume 14, Issue 4 , December 2021, Pages 85-98
Abstract
The need to improve the reliability and safety requirements, has led to increasingly utilization of reliability based design approaches. In this study, reliability based multidisciplinary design optimization for a bipropellant propulsion system has been investigated. The objective function is minimizing ...
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The need to improve the reliability and safety requirements, has led to increasingly utilization of reliability based design approaches. In this study, reliability based multidisciplinary design optimization for a bipropellant propulsion system has been investigated. The objective function is minimizing the total system mass and design constraints are the total impulse and the temperature of the wall of the combustion chamber. Monte Carlo simulation methodology is used to apply uncertainties in the problem and to show the reliability of the system under these uncertainties. The mass, functional and geometric results of the bipropellant propulsion system are differentiated for optimal design, reliability based design and optimal reliability based design. Then, considering the results, the concepts and definitions of design methods are compared and discussed and it is shown that the reliability based multidisciplinary optimization while having the desired mass, has high reliability.
