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Full-Text Articles in Mechanical Engineering
Experimental Investigation Of N2o/O2 Mixtures As Volumetrically Efficient Oxidizers For Small Spacecraft Hybrid Propulsion Systems, Rob L. Stoddard
Experimental Investigation Of N2o/O2 Mixtures As Volumetrically Efficient Oxidizers For Small Spacecraft Hybrid Propulsion Systems, Rob L. Stoddard
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
A hybrid thruster system utilizes propellants in two different stages, traditionally a solid fuel and a gaseous or liquid oxidizer. Recently hybrid thrusters have become a popular topic of research due to the high demand of a ”green” replacement for hydrazine. Not only are hybrid thruster systems typically much safer than hydrazine, but they are also a low-cost system with a high reliability in performance. The Propulsion Research Laboratory (PRL) at Utah State University (USU) has developed a hybrid thruster system using 3-D printed acrylonitrile butadiene styrene (ABS) as the fuel and gaseous oxygen (GOX) as the oxidizer. This system …
Spacecraft Guidance Techniques For Maximizing Mission Success, Shane B. Robinson
Spacecraft Guidance Techniques For Maximizing Mission Success, Shane B. Robinson
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Traditional spacecraft guidance techniques have the objective of deterministically minimizing fuel consumption. These traditional approaches to guidance are developed independently of the navigation system, and without regard to stochastic effects. This work presents and demonstrates a new approach to guidance design. This new approach seeks to maximize the probability of mission success by minimizing the variance of trajectory dispersions subject to a fuel consumption constraint. The fuel consumption constraint is imposed by formulating the dynamics in terms of a steering command, and placing a constraint on the final time. Stochastic quadratic synthesis is then used to solve for the nominal …
Experimental Testing Of The Accuracy Of Attitude Determination Solutions For A Spin-Stabilized Spacecraft, Keegan P. Ryan
Experimental Testing Of The Accuracy Of Attitude Determination Solutions For A Spin-Stabilized Spacecraft, Keegan P. Ryan
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Spin-stabilized spacecraft generally rely on sun and three-axis magnetic field sensor measurements for attitude determination. This study experimentally determines the total accuracy of attitude determination solutions using modest quality sensors. This was ac- complished by having a test spacecraft collect data during spinning motions. The data was then post-processed to find the attitude estimates, which were then compared to the experimentally measured attitude. This same approach will be used to test the accuracy of the attitude determination system of the DICE spacecraft to be built by SDL/USU.
Low-Thrust Assisted Angles-Only Navigation, Robert W. Gillis
Low-Thrust Assisted Angles-Only Navigation, Robert W. Gillis
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Tradition spacecraft proximity operations require large and expensive on-board sensors and significant ground support. Relative angle measurements can be obtained from small, simple, and inexpensive on-board sensors, but have not traditionally been used for proximity operation because of difficulty generating rang information. In this thesis it is shown that useful relative range data can be generated provided that the spacecraft is experiencing a small continuous thrust such as would be provided by a low-thrust propulsion system. In previous work range observability was shown with impulsive maneuvers. This thesis will expand this work to low-thrust spacecraft and will show how range …
Design Of The Guidance, Navigation, And Control Subsystem For The Proposed Firebird Spacecraft, Erin Robinson
Design Of The Guidance, Navigation, And Control Subsystem For The Proposed Firebird Spacecraft, Erin Robinson
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The Firebird spacecraft is a space mission to gather scientific and physical data on the effects of atmospheric deceleration, commonly called aerobraking. The objective of the Firebird mission is to measure specified aerobraking parameters over a range of reentry velocities to provide a database sufficient to construct and validate mathematical models of such aerobraking mission maneuvers. The Firebird senior design team designed the first spacecraft in the mission series to look at aerobraking at an altitude of 160 kilometers above the surface of the Earth. This paper looks specifically at the design of the subsystem that provides the guidance, navigation, …