M. Sc. Thesis

Author Introduction:
First name: Zahra
Last name: Hoodan
Entrance year: 2015
Defense date: 2018/Sep/12
Email address: z.hoodan12@email.kntu.ac.ir

Title: Cubesat Lunar Mission Design

In this thesis, the idea of having a mission to Moon using a cubesat and the process of mission design according to the defined steps, is presented. This process starts with presenting the mission definition and describing the parts that forms a mission. The mission analysis consists of describing the lunar mission objectives and constraints and also the idea of using Iranian Launch Vehicle, considering the mass constraint of third stage. The mission objective is technology demonstration and sending practical signal from lunar orbit. By defining mission concept elements, the mission analysis starts by defining orbit transfer and designing lunar trajectory and also calculating delta velocity budget for orbit part. After estimating mass budget of launch vehicles` third stage, the payload mass and dimensions of cubesats are determined. It is necessary to mention that this mission is possible, only if ion or cryogenic engines are used in launcher third stage. A brief description of cubesat subsystems characteristics is proposed, namely cubesat concept. The verification of project is done with STK software in order to design transfer trajectory and implement trajectory scenario.

Cubesat Lunar Mission Design
Place:17th International Conference of Iranian Aerospace Society, Islamic Azad University, Science and Research Branch
Year: June 2018

Author Introduction:
First name: Mahdi
Last name: Bayat
Entrance: 2016
Defense date: 2018/Sep/11
Email address: mahdi_bayat@email.kntu.ac.ir

Title: Systematic Design of a Satellite with Design Structure Matrix (DSM) Method

The purpose of this study is to introduce and propose design structure matrix in the conceptual designing phase for CubeSats.The designing process began from eliciting performance parameters and culminated in the formation of design structure matrix,determining dependencies and finally their optimization. Optimization of design structure matrix includes achieving designing sequence, control of interferences and designing parameters determined for the satellite. This method has been applied on a CubeSat with three units. Designing a three-unit CubeSat includes 61 performance parameters. These parameters have dependencies which have been considered in designing design structure matrix. After optimization of the qualitative relationships, quantitative designing of the parameters were conducted. After determining characteristics of the parameters and selection of the needed parts, technical budgets were proposed. Finally, the technical budgets were compared with the statistical data of the similar satellites and part selection and technical budgets were confirmed.

Author Introduction:
First name: Sara
Last name: Mirshekari
Entrance year: 2016
Defense date: 2018/Sep/11
Email address: sara_mirshekari@email.kntu.ac.ir

Title: GEO communication satellites reliability analysis based on operational life

The geosynchronous satellites as a complicated system with long orbital lifetime in order to design and manufacturing need to certain and step by step process allocation and reliability analysis. Regarding to the type of mission, complexity, operational lifetime and also inaccessibility for repairing and maintaining in orbit, it is very important to consider all aspects of failure and possible mistakes in functions of subsystems and equipment in different modes and phases of mission. for this reason, it has led to attract attention in order to diagnosis and analysis of failure sources in design and manufacturing phases and also regard to complexity of design and number of subsystems, it is  complicated and difficult to analyze and allocate reliability.
The purpose of this thesis is to determine a comprehensive process for analysis and allocation of satellite reliability according to functional lifetime. The presented process is a combination of statistical methods and FMECA[1], FTA[2], RBD[3] and FOO[4]. It has the ability to define the process of reliability allocation for a complicated system in different phases of design step by step. Accuracy of this method in this thesis was validated with two ways included: analytic (qualitative) way and numerical (quantitative) way. Statistical methods, FMECA and FTA were used for analytic validation and numerical validation was done by using of Kaplen-Meier, weibull, FOO allocation and RBD in order to validation. The represented process was implemented on a sample satellite and electrical power subsystem for geosynchronous satellite.[1]Failure Mode,Effect,and Criticality Analysis[2] Fault Tre Analysis[3] Reliability Block Diagram[4]  Feasibility Of Objectives

Reliability Modeling and analyzing for case study of the cube-sat LEO satellite
Place: International Reliability and Safety Engineering Conference
Year: 2018

Ph. D. Thesis