Sharif Digital Repository

The purpose of this project is to identify the most suitable propulsion system for a micro-satellite in LEO for orbit, altitude, and pointing corrections. Hence, different propulsion systems are investigated by comparing the propulsion thrust, mass, volume, cost, and specific impulse. In the first chapter, an introduction is given on micro-satellite and its subsystems. The second chapter discusses first the different types of disturbances that a microsatellite might face and second the control requirements for the satellite to counterbalance these disturbances. In the third chapter, different space propulsion systems are briefly reviewed and their main performance parameters discussed. In... 

Deployable structures have been used on small satellites since the beginning of such space programmes. Here, the design sequence for a special tensegrity structure, for use as supporting structure for deployable mesh-like antenna will be proposed. The design process is conducted to prevent structural elements from failure, and satisfy the minimum specified natural frequency. In this research, structural modeling is performed based on two external geometric parameters (overall height and diameter), and three internal geometric parameters (elements cross-section properties). The pre-stress in structural element is the last design parameter. Also, materials are pre-assigned. Internal forces of... 

Although Pulsed Plasma Thruster (PPT) has first been utilized in a space mission in 1964 but after more than four decades, it is still a space rated technology which has performed various propulsion tasks from stationkeeping tasks to three-axis attitude control for a variety of former missions. With respect to the rapid growth in the small satellite community and the growing interest for smaller satellites in recent years, PPT is one of the promising electric propulsion devices for small satellites (e.g. CubeSats) as the following advantages: simplicity, lightweight, robustness, low power consumptions, low production costs and small dimensions. In spite of the fact that the issues relating... 

Micro/Nano science has obtained enormous applications in aerospace engineering especially in the propulsion system of micro/nano satellites. The satellite attitude control is a vital part of every space mission. Different thruster systems have been already suggested and utilized to achieve this important mission correctly. Considering the future perspectives of space missions for small satellites, the development of micro/nano thrusters has been attracted more attention since the last decades. The scope of this research is to analyze hybrid hot/cold laboratory supersonic micro-thrusters especially for the micro-satellite implementations. The ultimate goal of the current research is to...