In emergency situations, where there is no possibility of using terrestrial-based or space-based telecommunication platforms or when there is a need for providing telecommunication services in remote, rural or hilly areas which are faced with lacking telecommunication infrastructures, typically using tethered balloon-based telecommunication technology is the best choice. Low operation cost, quick installation, larger coverage area than terrestrial facilities such as BTS and usability in emergency situations are among the advantages of using tethered balloons for telecommunication applications. Despite all the advantages of using this technology, small and limited coverage area is the biggest drawback of using tethered balloon platforms. In this paper, using a tethered balloon equipped with antenna pointing mechanism is proposed in order to, extend their small coverage area to a large region, in addition to benefit from inherent tethered balloons technology advantages. In this regard, dynamic and kinematic modeling of the proposed antenna pointing mechanism is discussed. In this research, the kinematic model is validated using RoboAnalyzer software and Robotics MATLAB toolbox. Antenna pointing mechanism provides the rotation ability for the antenna in two Azimuth and Elevation directions which increased the coverage area dramatically.
{"title":"Extensive Regional Telecommunications Coverage in Emergency Condition using Tethered-Balloon Equipped with Antenna Pointing Mechanism – Part 1: Kinematic and Dynamic Modeling","authors":"Mohammad Fathi, J. Ranjbar","doi":"10.30699/jsst.2022.1312","DOIUrl":"https://doi.org/10.30699/jsst.2022.1312","url":null,"abstract":"In emergency situations, where there is no possibility of using terrestrial-based or space-based telecommunication platforms or when there is a need for providing telecommunication services in remote, rural or hilly areas which are faced with lacking telecommunication infrastructures, typically using tethered balloon-based telecommunication technology is the best choice. Low operation cost, quick installation, larger coverage area than terrestrial facilities such as BTS and usability in emergency situations are among the advantages of using tethered balloons for telecommunication applications. Despite all the advantages of using this technology, small and limited coverage area is the biggest drawback of using tethered balloon platforms. In this paper, using a tethered balloon equipped with antenna pointing mechanism is proposed in order to, extend their small coverage area to a large region, in addition to benefit from inherent tethered balloons technology advantages. In this regard, dynamic and kinematic modeling of the proposed antenna pointing mechanism is discussed. In this research, the kinematic model is validated using RoboAnalyzer software and Robotics MATLAB toolbox. Antenna pointing mechanism provides the rotation ability for the antenna in two Azimuth and Elevation directions which increased the coverage area dramatically.","PeriodicalId":272394,"journal":{"name":"Journal of Space Science and Technology","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126767095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents a study concerning active vibration control of a smart flexible spacecraft during attitude maneuver using thrusters and reaction wheels (RW) in combination and piezoelectric (PZT) sensor/actuator patches. The large-angle maneuver and residual vibration of the spacecraft are controlled using an extended Lyapunov-based design (ELD) and strain rate feedback (SRF) theory for a two-mode mission. The single-axis fully coupled nolinear rigid-flexible dynamic of the system is derived applying a Lagrangian approach and Finite Element Method (FEM). The overall stability of the system including energetic terms covering a hub and two flexible appendages, torsional spring, RW, and PZT dynamics, has been proved and the control law has been derived accordingly. A pulse-width pulse-frequency (PWPF) modulation is used to alleviate the excitations of high-frequency flexible modes. However, due to the fast maneuver, there are still residual vibrations in the system. Hence, the SRF algorithm using PZT is applied to prepare further vibration suppression. A great feature of the proposed hybrid actuator system is the switching time of the thrusters and RW, which is based on total systems energy. The numerical results for a flexible spacecraft with large-angle, agile and precise maneuver requirements through a comparative study verify the merits of the proposed approach.
{"title":"Active Vibration Control of a Maneuvering Flexible Spacecraft using Hybrid Actuators: A Lyapunov-Based Control Approach","authors":"M. Azimi, S. Moradi","doi":"10.30699/jsst.2022.1276","DOIUrl":"https://doi.org/10.30699/jsst.2022.1276","url":null,"abstract":"This paper presents a study concerning active vibration control of a smart flexible spacecraft during attitude maneuver using thrusters and reaction wheels (RW) in combination and piezoelectric (PZT) sensor/actuator patches. The large-angle maneuver and residual vibration of the spacecraft are controlled using an extended Lyapunov-based design (ELD) and strain rate feedback (SRF) theory for a two-mode mission. The single-axis fully coupled nolinear rigid-flexible dynamic of the system is derived applying a Lagrangian approach and Finite Element Method (FEM). The overall stability of the system including energetic terms covering a hub and two flexible appendages, torsional spring, RW, and PZT dynamics, has been proved and the control law has been derived accordingly. A pulse-width pulse-frequency (PWPF) modulation is used to alleviate the excitations of high-frequency flexible modes. However, due to the fast maneuver, there are still residual vibrations in the system. Hence, the SRF algorithm using PZT is applied to prepare further vibration suppression. A great feature of the proposed hybrid actuator system is the switching time of the thrusters and RW, which is based on total systems energy. The numerical results for a flexible spacecraft with large-angle, agile and precise maneuver requirements through a comparative study verify the merits of the proposed approach.","PeriodicalId":272394,"journal":{"name":"Journal of Space Science and Technology","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130955796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High spatial and temporal variability of the tropospheric wet refractivity index, makes it difficult to present an accurate model for this variable. Up to now, Radiosonde stations data have been used for monitoring atmosphere parameters. Furthermore, because of the sparse distribution of radiosonde stations to monitor the lower levels of the atmosphere, the numerical weather models do not have enough accuracies for atmospheric parameters. Using the GPS tropospheric delay measurements and tomography approaches, the wet refractivity index can be estimated. In this research, three-dimensional and four-dimensional basis-function tomography is used to demonstrate the distribution of wet refractivity index of the troposphere. In this model, spherical cap harmonics are used for the horizontal distribution of the wet refractivity index, and empirical orthogonal functions are used for the vertical distribution of the index. In addition, temporal changes are considered by correlating the unknown coefficients using fourier series. The region of study is in the west California State, and the wet refractivity index is retrieved from the wet tropospheric delay measurements. To validate the results, radiosonde profiles were compared to the tomographically retrieved profiles. The results show that wet refractivity indices can be retrieved using functional models with RMSE about 2.4 ppm till 3.9 in the four-dimensional method. The comparisons show that the four-dimensional retrieved profiles show improvement up to 34 and 42 percentages in mid-day tomography epochs compared to the three-dimensional tomography results. Also it can be seen that in mid-night epochs, the three-dimensional tomography has higher accuracy compared to four-dimensional method because of low variation of wet refractivity indices.
{"title":"The retrieval of wet refractivity index by tomography using spherical cap harmonics","authors":"Masood Dehvari, S. Farzaneh, M. Sharifi","doi":"10.30699/jsst.2022.1256","DOIUrl":"https://doi.org/10.30699/jsst.2022.1256","url":null,"abstract":"High spatial and temporal variability of the tropospheric wet refractivity index, makes it difficult to present an accurate model for this variable. Up to now, Radiosonde stations data have been used for monitoring atmosphere parameters. Furthermore, because of the sparse distribution of radiosonde stations to monitor the lower levels of the atmosphere, the numerical weather models do not have enough accuracies for atmospheric parameters. Using the GPS tropospheric delay measurements and tomography approaches, the wet refractivity index can be estimated. In this research, three-dimensional and four-dimensional basis-function tomography is used to demonstrate the distribution of wet refractivity index of the troposphere. In this model, spherical cap harmonics are used for the horizontal distribution of the wet refractivity index, and empirical orthogonal functions are used for the vertical distribution of the index. In addition, temporal changes are considered by correlating the unknown coefficients using fourier series. The region of study is in the west California State, and the wet refractivity index is retrieved from the wet tropospheric delay measurements. To validate the results, radiosonde profiles were compared to the tomographically retrieved profiles. The results show that wet refractivity indices can be retrieved using functional models with RMSE about 2.4 ppm till 3.9 in the four-dimensional method. The comparisons show that the four-dimensional retrieved profiles show improvement up to 34 and 42 percentages in mid-day tomography epochs compared to the three-dimensional tomography results. Also it can be seen that in mid-night epochs, the three-dimensional tomography has higher accuracy compared to four-dimensional method because of low variation of wet refractivity indices.","PeriodicalId":272394,"journal":{"name":"Journal of Space Science and Technology","volume":"314 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128226156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study evaluates the expression level some genes that change by pressure changes in astronautics and divingdisorders in decompression sickness. This study was performed on 5 skilled divers and the expression level of TLR-2, HSP72, IL-1b, NF-kB and MPO genes, which are responsible for proinflammatory conditions, as well as the expression level of astronaut index genes, ie DRD4 and BNIP3 were analyzed on native Iranian samples. Blood samples were taken from healthy divers and controls, their RNA was extracted and cDNA was synthesized. PCRreal-time reactions were performed to investigate changes in gene expression using specific primers. Student's t-test statistical analysis showed that the expression level of all genes except MPO and TLR-2 genes increased significantly after exposure to pressure changes and diving activities. These changes can be considered as an indicator for healthy people under stress in space climbing as well as diving
{"title":"Evaluation of changes in the expression level of some genes involved in decompression sickness in the pressure changes","authors":"E. Siami, R. Mohammadi, V. zarrinpour","doi":"10.30699/jsst.2022.1357","DOIUrl":"https://doi.org/10.30699/jsst.2022.1357","url":null,"abstract":"This study evaluates the expression level some genes that change by pressure changes in astronautics and divingdisorders in decompression sickness. This study was performed on 5 skilled divers and the expression level of TLR-2, HSP72, IL-1b, NF-kB and MPO genes, which are responsible for proinflammatory conditions, as well as the expression level of astronaut index genes, ie DRD4 and BNIP3 were analyzed on native Iranian samples. Blood samples were taken from healthy divers and controls, their RNA was extracted and cDNA was synthesized. PCRreal-time reactions were performed to investigate changes in gene expression using specific primers. Student's t-test statistical analysis showed that the expression level of all genes except MPO and TLR-2 genes increased significantly after exposure to pressure changes and diving activities. These changes can be considered as an indicator for healthy people under stress in space climbing as well as diving","PeriodicalId":272394,"journal":{"name":"Journal of Space Science and Technology","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126573843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hanieh Eshaghnia, M. Nosratollahi, Amirhossain Adami, Hadi Dastoury
Turbopump propulsion systems have been used in almost all launch vehicles. With the advancement of manufacturing technologies, especially in the use of composite and lightweight structures, the use of non-turbopump propulsion systems has been considered due to the reduction of operating costs. This study has been investigated the multi-disciplinary optimization design of a two-stage launch vehicle using a pressure-fed propulsion system for both stages. Two main propulsion systems including gas-pressure and self-pressure feeding systems, have been evaluated in different configurations on two launcher stages. To extracting the optimum and possible solution, the launcher mission also has been added as a design variable in the optimization algorithm. The launcher has been extracted and introduced for each specific configuration of the launcher to achieve a certain orbital altitude with the maximum carrying payload and minimum gross mass. For this purpose, the AAO multidisciplinary optimization design framework has been used. The system-level and subsystem optimizer of the GA-SQP algorithm have been chosen.
{"title":"Multi-disciplinary optimization conceptual design of the launcher based on non-turbopump propulsion systems","authors":"Hanieh Eshaghnia, M. Nosratollahi, Amirhossain Adami, Hadi Dastoury","doi":"10.30699/jsst.2022.1286","DOIUrl":"https://doi.org/10.30699/jsst.2022.1286","url":null,"abstract":"Turbopump propulsion systems have been used in almost all launch vehicles. With the advancement of manufacturing technologies, especially in the use of composite and lightweight structures, the use of non-turbopump propulsion systems has been considered due to the reduction of operating costs. This study has been investigated the multi-disciplinary optimization design of a two-stage launch vehicle using a pressure-fed propulsion system for both stages. Two main propulsion systems including gas-pressure and self-pressure feeding systems, have been evaluated in different configurations on two launcher stages. To extracting the optimum and possible solution, the launcher mission also has been added as a design variable in the optimization algorithm. The launcher has been extracted and introduced for each specific configuration of the launcher to achieve a certain orbital altitude with the maximum carrying payload and minimum gross mass. For this purpose, the AAO multidisciplinary optimization design framework has been used. The system-level and subsystem optimizer of the GA-SQP algorithm have been chosen.","PeriodicalId":272394,"journal":{"name":"Journal of Space Science and Technology","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127638431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Strap-On Boosters Separation Analysis Using Coupled Simulation of Constraint Dynamics and Time Dependent CFD","authors":"Mostafa Jafari, A. Toloei","doi":"10.30699/jsst.2022.1169","DOIUrl":"https://doi.org/10.30699/jsst.2022.1169","url":null,"abstract":",","PeriodicalId":272394,"journal":{"name":"Journal of Space Science and Technology","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121384450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohammad Javad Poustini, S. Sadati, Yosof Abbasi, Seyyed Majid Hosseini
Trajectory optimization is a familiar method for most of re-entry and Re-usable vehicles. This is because of the ability to include almost all of the problem constraints without facing restrictions such as time & calculation issues. Adding or removing constraints in trajectory optimization problem has significant effects on overall optimization performance which even can upgrade the method to an online process. Most of optimization Algorithms such as nonlinear-programming need an initial guess and are also sensitive to it. Hence in this research management of initial guess is done to remove some constraints from optimization problem and transfer them to initial phase. Accordingly an effort is conducted through using a classic guidance method to satisfy constraints of distance error and angle of impact command. The output of guidance initial guess is then fed to the optimization problem. Differential Flatness has been used as a complementary idea to reduce size of optimization problem. 6Dof Simulation results show the increase of optimization performance via reduced number of iterations and Optimization time and increased solution accuracy
{"title":"Re-Entry Trajectory Design with Use of Aided Optimization Algorithm through Combination of Classic Guidance & Acceleration Profile Optimization","authors":"Mohammad Javad Poustini, S. Sadati, Yosof Abbasi, Seyyed Majid Hosseini","doi":"10.30699/jsst.2021.1311","DOIUrl":"https://doi.org/10.30699/jsst.2021.1311","url":null,"abstract":"Trajectory optimization is a familiar method for most of re-entry and Re-usable vehicles. This is because of the ability to include almost all of the problem constraints without facing restrictions such as time & calculation issues. Adding or removing constraints in trajectory optimization problem has significant effects on overall optimization performance which even can upgrade the method to an online process. Most of optimization Algorithms such as nonlinear-programming need an initial guess and are also sensitive to it. Hence in this research management of initial guess is done to remove some constraints from optimization problem and transfer them to initial phase. Accordingly an effort is conducted through using a classic guidance method to satisfy constraints of distance error and angle of impact command. The output of guidance initial guess is then fed to the optimization problem. Differential Flatness has been used as a complementary idea to reduce size of optimization problem. 6Dof Simulation results show the increase of optimization performance via reduced number of iterations and Optimization time and increased solution accuracy","PeriodicalId":272394,"journal":{"name":"Journal of Space Science and Technology","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126975327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Free vibration analysis of grid stiffened doubly curved composite shells using a refined higher order theory","authors":"Reza Kohandani, A. Davar, Mohsen Heydari beni, Jafar Eskandari Jam, Majid Eskandari Shahraki","doi":"10.30699/jsst.2022.1363","DOIUrl":"https://doi.org/10.30699/jsst.2022.1363","url":null,"abstract":"","PeriodicalId":272394,"journal":{"name":"Journal of Space Science and Technology","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134415673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The cold gas thruster is one of the significant components of a satellite and its application possesses a marked impact on the entire system performance. The nonlinear function and order of magnitude, lead to increasing the importance of thruster function. Therefore, pre-mission performance assessment has a considerable effect on the risk reduction of space missions. In this article, an uncomplicated and efficient pendulum scheme for development and implementation of a Thruster Test Stand (TTS), to measure the thrust produced at the end of the nozzle is proposed. The TTS is capable of measuring thrust levels in the range of 0.1Newtons to 3N with operating frequencies up to 50 Hz, which is used by various satellite ranges. The experimental results demonstrate that although the designed device is less sophisticated than other test devices, it is capable of measuring the produced thrust very precisely and with less than 15mN.
{"title":"Design, Construction and Performance Evaluation of a Cold Gas Thruster Test Stand","authors":"َAlireza Alikhani, Mohammad Reza Salimi","doi":"10.30699/jsst.2021.1305","DOIUrl":"https://doi.org/10.30699/jsst.2021.1305","url":null,"abstract":"The cold gas thruster is one of the significant components of a satellite and its application possesses a marked impact on the entire system performance. The nonlinear function and order of magnitude, lead to increasing the importance of thruster function. Therefore, pre-mission performance assessment has a considerable effect on the risk reduction of space missions. In this article, an uncomplicated and efficient pendulum scheme for development and implementation of a Thruster Test Stand (TTS), to measure the thrust produced at the end of the nozzle is proposed. The TTS is capable of measuring thrust levels in the range of 0.1Newtons to 3N with operating frequencies up to 50 Hz, which is used by various satellite ranges. The experimental results demonstrate that although the designed device is less sophisticated than other test devices, it is capable of measuring the produced thrust very precisely and with less than 15mN.","PeriodicalId":272394,"journal":{"name":"Journal of Space Science and Technology","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133097989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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