Engineering Commons^™

Linear Covariance Analysis For Gimbaled Pointing Systems, Randall S. Christensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Linear covariance analysis has been utilized in a wide variety of applications. Historically, the theory has made significant contributions to navigation system design and analysis. More recently, the theory has been extended to capture the combined effect of navigation errors and closed-loop control on the performance of the system. These advancements have made possible rapid analysis and comprehensive trade studies of complicated systems ranging from autonomous rendezvous to vehicle ascent trajectory analysis. Comprehensive trade studies are also needed in the area of gimbaled pointing systems where the information needs are different from previous applications. It is therefore the objective of …

Geosynchronous Earth Orbit/Low Earth Orbit Space Object Inspection And Debris Disposal: A Preliminary Analysis Using A Carrier Satellite With Deployable Small Satellites, Derick A. Crockett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

From communication to weather prediction, to national security, geosynchronous satellites play an important role in our society. Geosynchronous satellites are about 35,786 km (22,236 miles) from the surface of the earth. Getting a satellite to this altitude is very expensive, making geosynchronous satellites highly valued assets. Ground-based observation of these satellites is very limited and provides little insight when failures or anomalies occur. To provide detailed images and information of these critical satellites, highly functioning smaller satellites can be employed. This study explores the potential benefits of using these smaller satellites to perform on-orbit proximity inspections of geosynchronous satellites. The …

Error Modeling And Analysis Of Star Cameras For A Class Of 1u Spacecraft, David M. Fowler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As spacecraft today become increasingly smaller, the demand for smaller components and sensors rises as well. The smartphone, a cutting edge consumer technology, has impressive collections of both sensors and processing capabilities and may have the potential to fill this demand in the spacecraft market. If the technologies of a smartphone can be used in space, the cost of building miniature satellites would drop significantly and give a boost to the aerospace and scientific communities.

Concentrating on the problem of spacecraft orientation, this study sets ground to determine the capabilities of a smartphone camera when acting as a star camera. …

Spin Stability Of Sounding Rocket Secondary Payloads Following High Velocity Ejections, Weston Mcclain Nelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Auroral Spatial Structures Probe (ASSP) mission is a sounding rocket mission studying the effects of solar energy on space weather. ASSP requires the high speed ejection (up to 50 m/s) of 6 secondary payloads to gather the required data. The scientific instruments on the secondary payloads require that the payloads are stable in flight with coning angles of less than 5º, where the coning angle is the amount the payload is allowed to “wobble” about its spin axis. The secondary payloads are also required to have their spin axes aligned with 25º of the local magnetic field lines. Current …

Design And Testing Of Digitally Manufactured Paraffin Acrylonitrile-Butadiene-Styrene Hybrid Rocket Motors, Jonathan M. Mcculley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hybrid motors that employ non-toxic, non-explosive components with a liquid oxidizer and a solid hydrocarbon fuel grain have inherently safe operating characteristics. The oxidizer is blown though the solid fuel where it is combusted through a nozzle to produce thrust. This research investigated the combination of Acrylonitrile-butadiene-styrene impregnated with paraffin wax as the solid fuel component burned with nitrous oxide. The paraffin provides an enhanced regression rate over ABS; however, it lacks structural integrity and combustion efficiency. Multiple fuel grains with various ABS-to-Paraffin mass ratios were fabricated and burned with nitrous oxide. Analytical predictions for end-to-end motor performance and fuel …

Catalytic Decomposition Of Nitrous Oxide Monopropellant For Hybrid Motor Ignition, Matthew D. Wilson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrous oxide (N₂O), a commonly-used industrial gas, is also often used as a rocket motor oxidizer. It has been used in both hybrid rocket motors (using a solid fuel and a liquid oxidizer) and liquid rocket engines (using liquid fuel and oxidizer).

As a liquid form, nitrous oxide is highly stable, but in vapor form it can be decomposed, releasing large amounts of heat as it dissociates into nitrogen and oxygen. This project investigates using the energy from decomposing nitrous oxide to ignite a hybrid or liquid rocket. Such a system would be practical in rocket …

Development Of The Multiple Use Plug Hybrid For Nanosats (Muphyn) Miniature Thruster, Shannon Dean Eilers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Multiple Use Plug Hybrid for Nanosats (MUPHyN) prototype thruster incorporates solutions to several major challenges that have traditionally limited the deployment of chemical propulsion systems on small spacecraft. The MUPHyN thruster offers several features that are uniquely suited for small satellite applications. These features include 1) a non-explosive ignition system, 2) non-mechanical thrust vectoring using secondary fluid injection on an aerospike nozzle cooled with the oxidizer flow, 3) a non-toxic, chemically-stable combination of liquid and inert solid propellants, 4) a compact form factor enabled by the direct digital manufacture of the inert solid fuel grain. Hybrid rocket motors provide …

The Effect Of Navigation State Selection On Fuel Dispersions For Powered Lunar Descent, Jessica Thornley Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A Monte Carlo simulation is developed to study the performance of the closed-loop guidance, navigation, and control (GN&C) system of a lunar lander in powered descent. The simulation includes six-degrees-of-freedom dynamics, an extended Kalman filter, guidance based upon modified Apollo methods, an attitude control system, and several different types of sensors. Sensors included in the sensor suite include accelerometers, gyroscopes, a star camera, an altimeter, a velocimeter, and a radio navigation system. The simulation is used to examine the effects of sensor errors and the number of navigation states on total fuel use.