Space engineering
Hamed Sheikhbahaee; Farkhondeh Saliminezhad; Seyed Alireza Ghorashi; Saeed Hajialigol
Abstract
Ion mobility spectroscopy (IMS), as one of the detection methods based on the ionization of mineral, organic, and chemical substances, has been used efficiently for many years in manned and robotic space missions. The space applications of these instruments include environmental monitoring of spacecraft ...
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Ion mobility spectroscopy (IMS), as one of the detection methods based on the ionization of mineral, organic, and chemical substances, has been used efficiently for many years in manned and robotic space missions. The space applications of these instruments include environmental monitoring of spacecraft and identification of organic and mineral substances in samples collected from space. In this method, warm-up is required for the cleanup and transport of ions in the drift area of the detector cell. Considering the need to miniaturize and optimize the necessary power of space detectors, the experimental investigation of the thermal gradient and factors affecting warm-up time is essential. For conducting the experimental thermal analysis of the IMS cell, micropumps, desorber, and temperature recording equipment such as a temperature control system, data logger, thermocouple sensors, monitoring system, and resistance temperature detector have been used. In this research, by experimentally investigating the warm-up time and thermal gradient in the IMS cell in different modes and several target temperatures, the main factors have been determined. The results showed that the oscillating air flow inside the IMS cell can reduce the warm-up time and the temperature gradient. Finally, several suggestions for better thermal efficiency are presented.
Space engineering
Roya Sanaie; Pouya Talebinejad; Seyed Mohammadjavad Tabatabiee; Mahdi Fakoor
Abstract
The solar array ,one of the main parts of the satellite's electrical power subsystem, is responsible for providing the required electrical power for the satellite during the mission. Micrometeorites and small space debris are considered serious risk for the satellite mission. Due to the number of satellites ...
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The solar array ,one of the main parts of the satellite's electrical power subsystem, is responsible for providing the required electrical power for the satellite during the mission. Micrometeorites and small space debris are considered serious risk for the satellite mission. Due to the number of satellites in orbit, space debris is increasing. The impact of micrometeorites or orbital debris on the solar panels of the satellite can damage the internal structure of the panel, which causes a drop in the electrical power of the satellite. In this article, along with the numerical and geometrical simulation of the solar panels of the MEO communication satellite, an algorithm based on the direct random impact of micrometeorites and orbital debris on the solar panels has been presented, and their damage rate has been calculated. The size of meteorites and space debris is determined based on the average size of the particles in the earth's orbit. After summarizing the collision results, the redundant solar panel has been simulated based on the minimum and maximum damage to compensate for the satellite power loss. The results show that the redundant solar panel can compensate the loss of satellite power after the collision and estimate the extent of damage as soon as possible
Flight dynamics
Behrooz Raeisy; Fatemeh Ghofrani
Abstract
Various sensors can be used to attitude determination of a satellite, including the Earth Horizon Sensor. These sensors generally divided into two types: static and scanning types. In the static type, two- dimensional array or several linear arrays capture instantly the Earth image information to attitude ...
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Various sensors can be used to attitude determination of a satellite, including the Earth Horizon Sensor. These sensors generally divided into two types: static and scanning types. In the static type, two- dimensional array or several linear arrays capture instantly the Earth image information to attitude determination. In the scanning type sensors, a narrow-band optical beam mechanically sweeps a ring of space to find the crossing point of the beam to the Earth using a single spot detector. In this research, a new algorithm for a static earth horizon sensor with a two-dimensional array is presented. The algorithm does not need elevation of the sensor and this is the main advantage with respect to old ones. To extract the equations, a tangent vectors from the aperture of the pine- hole camera to the Earth is considered and this vector is extracted in two different body coordinates and base coordinates that are connected to the ground. By equating the two, an equation with three unknowns of pitch, roll and elevation is obtained. The equation is satisfied by each pixel on the Earth horizon Thus; the system of equations is formed by the number of the Earth horizon pixels in the camera image and parameters are estimated by numerical solving of the unknown equations.
