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.
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.
Space Engineering
Mohammad N. Meibody; Hassan Naseh; Fathollah Ommi
Volume 12, Issue 4 , December 2019, , Pages 35-46
Abstract
Now, the required samples to achieve the specific precision of sensitivity analysis in design are performed based on trial and error methods. The purpose of this paper is to develop an approach for determining the number of the required sample to achieve the specific precision of sensitivity analysis. ...
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Now, the required samples to achieve the specific precision of sensitivity analysis in design are performed based on trial and error methods. The purpose of this paper is to develop an approach for determining the number of the required sample to achieve the specific precision of sensitivity analysis. Thus, in this paper, a new sensitivity analysis method is proposed based on the Progressive Latin hypercube Sampling (PLHS) and the convergence of the analysis results. For this purpose, a PLHS method has been developed. This cystic approach has led to a sensitivity analysis of accuracy, efficiency, and speed in a variety of models with a large number of large parameters and large changes. Sensitivity analysis has been performed on the design of a hydrazine monopropellant thruster catalyst bed model as a case study. The results of this study indicate that in the sensitivity analysis based on the PLHS, the minimum population required for sensitivity analysis with specified accuracy can be determined. This leads to lower processing costs in the sensitivity analysis process, especially in complex models.
