İSTANBUL TEKNİK ÜNİVERSİTESİ ★ UÇAK ve UZAY BİLİMLERİ FAKÜLTESİ Nanosat ADCS Design and Performance Analysis UNDERGRADUATE THESIS PROJECT Veysel Abdullah TEKİN (110140156) Department of Aerospace Engineering Thesis Advisor : Professor Doctor Alim Rüstem ASLAN February 2021 i İSTANBUL TEKNİK ÜNİVERSİTESİ ★ UÇAK ve UZAY BİLİMLERİ FAKÜLTESİ Nanosat ADCS Design and Performance Analysis UNDERGRADUATE THESIS PROJECT Veysel Abdullah TEKİN (110140156) Department of Aerospace Engineering Thesis Advisor : Professor Doctor Alim Rüstem ASLAN February 2021 ii Veysel Abdullah TEKİN, student of ITU Faculty of Aeronautics and Astronautics student ID 110140156, successfully defended the graduation entitled “NANOSAT ADCS DESIGN AND PERFORMANCE ANALYSIS”, which he/she prepared after fulfilling the requirements specified in the associated legislations, before the jury whose signatures are below. Thesis Advisor : Prof. Dr. Alim Rüstem ASLAN ………………… İstanbul Technical University Jury Members : Prof. Dr. Cengiz HACIZADE ………………… İstanbul Technical University Dr. Öğr. Üyesi Cuma YARIM ………………… İstanbul Technical University Date of Submission : 1 February 2021 Date of Defense : 8 February 2021 iii To Dr. Öğr. Kemal Bülent Yüceil and Halit Ayar iv FOREWORDS First of all, I am very happy and proud to have graduated from Technical University. The meaning of taking lessons from the Faculty of Aeronautics and Astronautic’s Academicians is that The privilege that was only able to get 80 people each year in Turkey. My process of determining the subject of my graduation thesis developed as follows. I met with aerospace engineering during the Introduction to Aerospace Engineering lecture opened by Dr. Öğr. Cuma YARIM. Due to the content of the course, I got acquainted with topics such as orbit mechanics, imaging techniques and satellite technology thus I started to lay the foundations of what I want to study in the future. The late Dr. Öğr. Kemal Bülent YÜCEIL had a very special place in me as well as everyone else in the Faculty. I learned orbital mechanics in depth from Dr. Öğr. Kemal Bülent YÜCEIL, He was a great scientist. In this way, I started to create the infrastructure for the location. May Allah raise your soul to the highest heights! In the 4th year, I took the Attitude control and determination systems course from Prof. Dr Cengiz HACIZADE. Thanks to the course, I understood the key role and working principles of Attitude Determination and Control in order to perform the missions of all spacecraft. Finally, In Spacecraft Systems Design course, which is considered a undergraduate course. In this course, Prof. Dr. Alim Rüstem ASLAN made us work with the content that we could use what we learned in 4 years and feel like a real Aerospace Engineer. Working with Prof. Dr. Alim Rüstem ASLAN was unique experience as an aerospace engineer candidate. During this period, I followed his work from the press and felt proud. Thank you very much for everything. To sum up, I am grateful for all your efforts and dedication. February 2021 Veysel Abdullah TEKİN v vi TABLE OF CONTENT Page FOREWORDS v TABLE OF CONTENT vii ABBREVIATIONS ix LIST OF FIGURES x SUMMARY xi ÖZET xiii 1. INTRODUCTION 1 2. ATTITUDE DETERMINATION SYSTEMS 2 2.1 Reference Frames 2 2.1.1 Sun Referenced 2 2.1.2 Central Body Referenced 3 2.1.3 Magnetic Field Referenced 3 2.1.4 Stars and Distanced Planet Referenced 4 2.1.5 Inertial Referenced 4 2.2 Attitude Determination Algorithms 4 2.3 Attitude Determination Systems Sensors 5 2.3.1 Star Tracker 5 2.3.2 Sun Sensor 6 2.3.2.1 Analog Sun Sensor 6 2.3.2.2 Digital Sun Sensor 7 2.3.3 Magnetometer 7 2.3.4 Horizon Sensor 8 2.3.5 Global Positioning System (GPS) 8 2.3.6 Gyroscope 9 2.3.6.1 The gyroscope has two principles 9 3. ATTITUDE CONTROL SYSTEMS 12 3.1 Active Systems 12 3.1.1 Gas Jets/Thruster 12 3.1.2 Reaction Wheels 13 3.1.3 Magnetorquer 13 3.1.4 Ion Thruster 14 vii 3.2 Passive Systems 15 3.2.1 Spin stabilized 15 3.2.2 Gravity Gradient Stabilization 16 4. SIMILAR MISSIONS 18 4.1 CubeSat List 18 4.2 ADC Analysis Of Similar Cube Satellites According To Their Duties 22 5. MISSIONS : ADCS SELECTIONS 25 5.1 Earth Observation Mission 25 5.1.1 Mission in brief 25 5.1.2 Camera’s Point of View Calculation 26 5.1.3 Selected Attitude Determination and Control System 26 5.1.4 Reason for Choice 26 5.2 Mapping Mars South Pole 28 5.2.1 Mission in brief 28 5.2.2 In Scenario 1: Mapping Mars South Pole 29 5.2.2.1 Mission in brief 29 5.2.2.2 In Scenario 1, Camera's Point of View Calculation 29 5.2.2.3 Scenario 1, Selected Attitude Control and Determination 30 5.2.2.4 Reason for Choice 30 5.2.3 In Scenario 2: Mapping Mars South Pole 31 5.2.3.1 Mission in brief 31 5.2.3.2 In Scenario 2, Camera's Point of View Calculation 31 5.2.3.3 Scenario 2, Selected Attitude Control and Determination 32 5.2.3.4 Reason for Choice 32 5.3 Sun Observation 33 5.3.1 Mission in brief 33 5.3.2 Selected Attitude Determination and Control Systems 33 5.3.3 Reason for Choice 34 CONCLUSION 35 REFERENCE 36 CURRICULUM VITAE 41 viii ABBREVIATIONS ADCS : Attitude Determination and Control Systems ADS : Attitude Determination Systems ACS : Attitude Control Systems GPS : Global Positioning System ix LIST OF FIGURES Page Figure 1 : Closed Loop of ADCS xi Figure 2.1 : References Frames 2 Figure 2.1.1 : Central Body Referenced Frame 3 Figure 2.1.2 : Density of The Earth Magnetic Field 4 Figure 2.3 : Basic Working Principle of Star Tracker 5 Figure 2.3.1 : Star Tracker in PicSat 6 Figure 2.3.2 : Basic Analog Sun Sensor Working Principle 6 Figure 2.3.3 : NASA’s Digital Sun Sensor and Its Working Principle Basically 7 Figure 2.3.4 : Magnetometer Working Principle 7 Figure 2.3.5 : Horizon Sensor Principle 8 Figure 2.3.6 : GPS, ADS Working Principle and Signal Catching with Antenna 9 Figure 2.3.7 : Gyroscope Working Principle 9 Figure 2.3.8 : Gyroscope’s Precession Principle Formula 10 Figure 3.1 : Apollo 11’s Thruster 12 Figure 3.1.1 : Reaction Wheel Devices 13 Figure 3.1.2 : Magnetorquer for CubeSat 14 Figure 3.1.3 : Ion Thruster Schema and Working Principle 15 Figure 3.2 : Spin Stabilization Working Principle 15 Figure 3.2.1 : Gravity-Gradient Stabilization Working Principle 16 Figure 5.1 : Earth Observation’s Concept Of Operation 25 Figure 5.1.1 : Point of View Calculation 26 Figure 5.2 : Mars South Pole’s Mapping Concept Of Operation 28 Figure 5.2.1 : In Scenario 1: Mars South Pole’s Mapping Concept Of Operation 29 Figure 5.2.2 : In Scenario 1, Camera's Point of View Calculation 29 Figure 5.3 : In Scenario 2: Mapping Mars South Pole Concept Of Operation 31 Figure 5.3.1 : In Scenario 2: Camera's Point of View Calculation 31 Figure 5.4 : Sun Observation Concept Of Operation 33 x Nanosat ADCS Design and Performance Analysis SUMMARY Attitude determination and control system consists of 2 main titles determination and control. attitude determination is the process of providing the spacecraft's current orientation information in space. The instantaneous orientation of the spacecraft is one of the two basic inputs for the realization of the mission. Control refers to the process of transition from the current management to its new orientation or maintaining orientation in line with the instructions. The control may not always be active. The requirements of the task affect the attitude determination and control systems type. Spacecraft use many sensor activators and algorithms in the Attitude determination and control process. This relationship is shown in the diagram below. Figure 1 : Closed Loop of ADCS (Markley & Crassidis, 2014, pp. 1–3) According to the given scheme, first the data received from the sensor for the orientation of the satellite is processed with the algorithm and the location is determined according to the result of the algorithm. The order is created or it occurs autonomously. Thus, it passes to the software stage of the control system, the command created here turns into dynamite through the activator and the closed loop starts again. For example, TRYAD cubesat is in charge of measuring the amount of Gamma rays in storms. It should be directed towards the storm detected due to its mission and should monitor the region precisely during the storm. Therefore, it uses high precision sun sensor and reaction xi wheel, so it can precisely determine and control attitude. In order to monitor the area in question with high precision, the observation mission can control its orientation with the reaction wheel used in spacecraft. Attitude determination systems vary according to the degree of sensitivity and reference, while control systems are examined under two headings as active and passive. First of all, attitude determination systems are as follows; star tracker, sun sensor, Earth / Horizon (body centered), Magnetometer, Global Positioning System GPS and Gyroscope. Each of these systems has different reference systems for different purposes and different requirements. Each system details will be covered in the following sections. There are two different types of control systems, active and passive. Active systems are Gas jets, magneto torquer, ion thruster, reaction wheel and hysteresis rods, respectively. Passive ones are; spin stabilized, gravity gradient stabilized. (Markley & Crassidis, 2014, pp. 1–3) xii Nanosat ADCS Design and Performance Analysis ÖZET ADCS, 2 Ana başlıktan oluşur Yönelim belirleme ve kontrol.