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Full-Text Articles in Astrodynamics

Orbit Determination With Event-Based Cameras To Improve Space Domain Awareness, Conor M. Wisentaner Sep 2022

Orbit Determination With Event-Based Cameras To Improve Space Domain Awareness, Conor M. Wisentaner

Theses and Dissertations

The objective of this research is to assess the utility of a COTS EBC for SDA applications by evaluating its ability to produce data for orbit updates of resident space objects. Unlike traditional frame-based imaging sensors, the pixels on an EBC activate independently when a change in brightness is detected to produce a continuous data flow on a per pixel basis. This unique functionality provides much higher temporal resolution than traditional frame-based sensors, such that an EBC can generate far more data points from a single observation than a frame-based sensor. However, current COTS EBCs have less spatial resolution than …


Spacecraft Trajectory Optimization Suite: Fly-Bys With Impulsive Thrust Engines (Stops-Flite), Aaron H. Li Jun 2022

Spacecraft Trajectory Optimization Suite: Fly-Bys With Impulsive Thrust Engines (Stops-Flite), Aaron H. Li

Master's Theses

Spacecraft trajectory optimization is a near-infinite problem space with a wide variety of models and optimizers. As trajectory complexity increases, so too must the capabilities of modern optimizers. Common objective cost functions for these optimizers include the propellant utilized by the spacecraft and the time the spacecraft spends in flight. One effective method of minimizing these costs is the utilization of one or multiple gravity assists. Due to the phenomenon known as the Oberth effect, fuel burned at a high velocity results in a larger change in orbital energy than fuel burned at a low velocity. Since a spacecraft is …


Orbital Debris Analysis And Orbital Decay Analysis Of Arksat-2, Will Stuff May 2022

Orbital Debris Analysis And Orbital Decay Analysis Of Arksat-2, Will Stuff

Mechanical Engineering Undergraduate Honors Theses

ARKSAT-2 is a cube satellite developed by the University of Arkansas for its second CubeSat mission. There are two objectives of the ARKSAT-2 mission. The first objective of this mission is to test a novel cold gas thruster propulsion system using water-propylene propellant. This propulsion system will be used for attitude control of the satellite. The second objective for the ARKSAT-2 mission is to test a Solid-State Inflation Balloon (SSIB) that has been designed and developed for this mission. The SSIB is designed to be a simple and cost-effective method for deorbiting the vehicle. In cube satellites, a software known …


Dynamic Analysis Of Cubesat Impact On Lunar Surface, Dalton C. Korczyk Apr 2022

Dynamic Analysis Of Cubesat Impact On Lunar Surface, Dalton C. Korczyk

Doctoral Dissertations and Master's Theses

EagleCam is a pico-satellite (CubeSat) with dimensions of 100 x 100 x 150 mm3 that is going to the moon as a payload of the Intuitive Machines Nova-C lunar lander. The CubeSat’s purpose is to record the lunar landing from a 3rd person view. Unlike other CubeSats, EagleCam is designed to impact the lunar surface and there is no history to build off of. Specifically, EagleCam will need to survive a 30 m drop onto the lunar surface with all internal components fully operational post impact. This thesis is focused on the analytical, numerical, and experimental methods for determining the …


Coupled Orbit-Attitude Dynamics And Control Of A Cubesat Equipped With A Robotic Manipulator, Charles M. Carr Mar 2022

Coupled Orbit-Attitude Dynamics And Control Of A Cubesat Equipped With A Robotic Manipulator, Charles M. Carr

Theses and Dissertations

This research investigates the utility and expected performance of a robotic servicing CubeSat. The coupled orbit-attitude dynamics of a 6U CubeSat equipped with a four-link serial manipulator are derived. A proportional-integral-derivative controller is implemented to guide the robot through a series of orbital scenarios, including rendezvous and docking following ejection from a chief spacecraft, repositioning the end effector to a desired location, and tracing a desired path with the end effector. Various techniques involving path planning and inverse differential kinematics are leveraged. Simulation results are presented and performance metrics such as settling time, state errors, control use, and system robustness …


Underactuated Attitude Control Of A Cubesat Using Cold Gas Thrusters And Nonlinear Control Methods, Adam S. Cottrell Mar 2022

Underactuated Attitude Control Of A Cubesat Using Cold Gas Thrusters And Nonlinear Control Methods, Adam S. Cottrell

Theses and Dissertations

Impulsive thrusters on small satellites, such as CubeSats, are typically used for attitude control. However, to become more agile, small CubeSats must also look to propulsion systems utilizing impulsive thrusters, such as cold-gas, for translational maneuvers. The combined thrust vector is often misaligned with the system's center of mass resulting in a disturbance torque. This must be counteracted by either an attitude determination and control system (ADCS), additional thrusters, or a control method to keep the satellite's attitude at or near equilibrium. Nonlinearities generated by the impulsive maneuvers are overcome via control techniques explored in this research to include on-off …


Probabilistic Space Weather Modeling And Forecasting For The Challenge Of Orbital Drag In Space Traffic Management, Richard J. Licata Iii Jan 2022

Probabilistic Space Weather Modeling And Forecasting For The Challenge Of Orbital Drag In Space Traffic Management, Richard J. Licata Iii

Graduate Theses, Dissertations, and Problem Reports

In the modern space age, private companies are crowding the already-congested low Earth orbit (LEO) regime with small satellite mega constellations. With over 25,000 objects larger than 10 cm already in LEO, this rapid expansion is forcing us towards the enterprise on Space Traffic Management (STM). STM is an operational effort that focuses on conjunction assessment and collision avoidance between objects. While the equations of motion for objects in orbit are well-known, there are many uncertain parameters that result in the uncertainty of an object's future position. The force that the atmosphere exerts on satellite - known as drag - …