This document got churned in my chaotic 2023, maybe I will revisit this one day and finish it. For now it remains unfinished. ________ # Introduction The purpose of this document is twofold: to enhance my comprehension of the subject at hand and to develop a valuable resource for future reference. By delving deeper into this topic, I aim to broaden my understanding and strengthen my knowledge base, thereby facilitating my academic journey at the university level. This document serves as a strategic tool to aid my progress and provide me with a convenient reference point throughout my university studies. By compiling comprehensive information, explanations, and insights, it will offer me a reliable source of information that can support my learning and assist me in tackling complex concepts with ease. ## In this document the following subjects will be covered: - Spin Stabilization [[Stabilization Methods for Small Artificial Satellites in Orbit#Spin Stabilization|Here]] - Three-Axis Stabilization [[Stabilization Methods for Small Artificial Satellites in Orbit#Three Axis Stabilization|Here]] - Gravity Gradient Stabilization [[Stabilization Methods for Small Artificial Satellites in Orbit#Gravity Gradient Stabilization|Here]] - Magnetic Torquing [[Stabilization Methods for Small Artificial Satellites in Orbit#Magnetic Torquing|Here]] - Control Moment Gyros (CMGs) [[Stabilization Methods for Small Artificial Satellites in Orbit#Control Moment Gyros (CMGs)|Here]] - ==Add more here later== ## A personal note: Undertaking this research holds great significance for me, driven not only by my fascination with the subject matter but also by my career aspirations. With a profound passion for the field of aerospace engineering, and space as a whole my ultimate goal is to contribute to the ground- breaking work carried out by NASA, specifically in the realm of satellite design. By dedicating myself to this research, I aim to acquire the necessary knowledge and skills to make meaningful contributions to future projects, including those that explore potentially habitable celestial bodies in our galaxy. The prospect of working alongside the brilliant minds at NASA, pushing the boundaries of human understanding, and venturing into the vastness of the galaxy, inspires me deeply. By delving into the depths of this subject, I strive to develop a robust foundation of knowledge and expertise that will position me as a valuable asset in the pursuit of these ambitious goals. Through rigorous research, honing my engineering skills, and immersing myself in the intricacies of satellite design, I hope to contribute to the advancement of space exploration and the quest to find a home for humanity across the cosmos. ------- # Active Attitude Control Active methods for spacecraft stabilization, whether applied to a cube sat or the International Space Station, depend on continuous attitude monitoring and corrective actions to keep the spacecraft within mission parameters. For instance, when the spacecraft deviates beyond its permitted range of motion, an external thruster is triggered to propel the spacecraft back into the designated parameters. These active systems employ components that vigilantly assess attitude and execute necessary adjustments, ensuring the spacecraft remains precisely oriented throughout its mission. ## Three Axis Stabilization ==This is just a summary, add much more detail== Three axis stabilization uses one of two methods to maintain attitude. The first is using small thrusters to correct the spacecrafts attitude, while effective, this method induces a rocking motion in the craft making it more difficult to precisely use on board instruments. The other method is using reaction wheels, or alternatively known as momentum wheels. These wheels are placed in three orthogonal axes on the spacecraft. This allows the craft to adjust attitude by spinning the wheels in the opposite direction of the desired movement (Newton's third law). It would seem logical to use a combination of these two methods to achieve the best results. ## Control Moment Gyros (CMGs) ==This is just a summary, add much more detail== Control moment gyros are similar to the reaction wheel method applied by [[Stabilization Methods for Small Artificial Satellites in Orbit#Three Axis Stabilization|Three Axis Stabilization]] but they are different in their method of generating torque. While three Axis Stabilization (TAS from here on out) uses reaction wheels that start statically as a means to generate torque by exchanging angular momentum for attitude adjustment in the spacecraft. Control moment gyros use reaction wheels as well but in this method they are spinning by default and use acceleration and deceleration of the wheels as the means of generating torque on the spacecraft. # Passive Attitude Control Passive attitude control systems for spacecraft rely on inherent design features and principles of physics to maintain stability without constant monitoring or active corrections. They employ mechanisms such as reaction wheels, magnetorquers, and passive stabilization devices to counteract disturbances and adjust the satellite's attitude without the need for external thrusters. By leveraging these inherent properties and the laws of physics, passive attitude control systems provide a simpler and more robust approach to ensure long-term stability in satellite missions. ## Spin Stabilization ==This is just a summary, add much more detail== Spin Stabilization is fairly basic of a system, by spinning the entire satellite along the axis with the largest moment of inertia the satellite will be stable. However, when it comes to satellites, the need for a rod or ball bearing is eliminated. This is because satellites operate in a zero-gravity (zero G) environment where the effects of gravity are negligible. Additionally, there is minimal friction present in space. Consequently, satellites can achieve spin stabilization effortlessly, as the absence of gravitational forces and friction allows them to maintain a steady spin without any external aids. ## Gravity Gradient Stabilization/ Tidal Stabilization ==This is just a summary, add much more detail== Tidally stabilizing a spacecraft is a fascinating method, by using the shape of the spacecraft as a way to harness the earths gravitational pull selectively on the spacecraft, it is possible to pull the spacecraft into a desired attitude passively. The effect is that the satellite will tend to align its axis of minimum [moment of inertia](https://en.wikipedia.org/wiki/Moment_of_inertia "Moment of inertia") vertically. By leveraging the varying gravitational forces acting on its asymmetrical shape, [GP-B](https://en.wikipedia.org/wiki/Gravity_Probe_B)successfully measured geodetic and frame-dragging effects, confirming Einstein's predictions. ## Magnetic Torquing ==This is just a summary, add much more detail== A magnetorquer (also known as a **torque rod**) uses electromagnetic coils to interface with earths magnetic field causing the spacecraft to stabilize, have attitude control and detumble. The magnetorquer creates a magnetic dipole that interfaces with an ambient magnetic field, usually [Earth's](https://en.wikipedia.org/wiki/Earth%27s_magnetic_field "Earth's magnetic field"), so that the counter-forces produced provide useful [torque](https://en.wikipedia.org/wiki/Torque "Torque").