Journal of Space Science and Technology
Year:2019 | Volume:12 | Issue:1 (38)|Papers Count:6

Following the beginning of human activities in outer space, such issues as governance, jurisdiction and other legal matters were investigated by jurists. It should be accepted that technological advancement cannot be made possible in the presence of legal gaps, and it should be acknowledged that law is easily changing and developing constantly. With increasing progression law of outer space is essential. humans having access to the outer space, it is extremely essential and important to develop international law governing the outer space and celestial Bodies. As the most resent branch of international law, therefore, International Space law provides new concepts related to criminal jurisdiction for this reason, present paper attempts to explain criminal jurisdiction within international law system while evaluating its position in the framework of international outer space law on interrelated issues such as command authority, authority of commanding the international space stations, and Command of the International Space Station and commanders in light of U. N outer space treaty.

In this paper, design and physical configuration of various components of a 10N Monopropellant Hydrazine Thruster focusing on design calculations and optimization of catalytic combustion chamber. According to this design, a prototype of the thruster will be manufactured. The mentioned thruster has been designed as a three-piece modular thruster, including an injection system, catalytic combustion chamber and nozzle. Based on analyzes done for each module, the propulsion characteristics of monopropellant thruster system have been identified and used for the next module as necessary inputs. The combustion chamber dimensions are selected based on criterion of maximum decomposition of 40% ammonia and Mach number of 0. 02. Also, the third module is the nozzle, designed as a simple cone. The exterior body design of these three modules and their connections to each other, based on considerations of sizing and weight limitation, as well as being dual purpose for use in the cold and hot tests, has been performed.

Micro-propulsion Systems are low thrust engines that be used in space missions like keeping satellite in orbit and changing orbit. These engines have several kinds and liquid propellant micro-propulsion is used in this project. In two propellant micro-propulsion systems, various fuels and oxidizers can be used. Kerosene is used as fuel and liquid oxygen is used as oxidizer in this project. First of all, a micro-propulsion is designed and analysis of combustion, heat transfer, nozzle exit flow and amount of performance’ s parameters is done with RPA software. Similar to big engines, micro-propulsion systems have injectors, injection plate, combustion chamber and nozzle. Design of all of this parts will be explained. With manufacturing of designed model and perform hot fire test, accurate performance of engine is observed. Finally, performance’ s parameters in hot fire test are compared with performance’ s parameters in RPA.

Considering the importance of the presence of uncertainties in the design of complex engineering systems, in this research multidisciplinary design optimization process for a bipropellant propulsion system in the presence of uncertainties, which in addition to minimizing the system mass, has a high robust. Based on this, the multidisciplinary design view of the bipropellant propulsion system is expressed in both optimum design and optimum robust design. The continued with the application of uncertainties, the mass, operational and geometric results of the propulsion system are expressed in terms of optimum design, robust design and optimum robust design. According to the results, it is shown that the lowest mass occurs in optimum design mode. But with uncertainties, it is observed at this point that it has the least robust and reliability. It also attempts to explain the difference between the concepts of robust design and optimum design with the help of results.

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.

Gravity is one of the most important forces exposed to the organisms on the earth which affects the cells, molecules and thus the entire of organism. The purpose of this study is to investigate the effect of the simulated microgravity on the changes of RKIP metastasis suppressor gene expression on MDA-MB-231 breast cancer cell line. In order to impose microgravity state, cancer cells were placed on clinostat for one and three days. Then RNA was extracted from the cells and RKIP gene expression changes were evaluated by qReal time PCR. The findings showed that the microgravity during one day reduced the RKIP expression level, but with continuing up to three days, the expression returned to the control level. By optimizing the duration of microgravity, it can be likely observed the significant effects on the RKIP gene expression changes and so that useful steps can be taken to discover the cancer mechanisms and its treatment.