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Full-Text Articles in Engineering
Space Qualification Testing Of A Deployable Shape Memory Alloy Cubesat Antenna, Carl L. Kobza
Space Qualification Testing Of A Deployable Shape Memory Alloy Cubesat Antenna, Carl L. Kobza
Theses and Dissertations
Increasingly capable CubeSat missions require antenna with improved Radio Frequency performance over the traditional CubeSat antennas. Deployable quadrifilar helical antennas (QHA) enable an acceptable stowing volume and deploy to provide increased gain and bandwidth over traditional patch and dipole antennas. Extensive ground testing is required to ensure the antenna is space qualified and to characterize the antenna deployment in the space environment. AFIT requires a QHA to perform a future CubeSat geolocation mission and contracted Helical Communication Technologies (HCT) to design and manufacture a Shape Memory Alloy (SMA) L-band deployable QHA. Vibration, thermal vacuum, laser vibrometer, and Voltage Standing Wave …
Test And Verification Of A Cubesat Attitude Determination And Control System In Variable Magnetic Fields, Eric A. Bassett
Test And Verification Of A Cubesat Attitude Determination And Control System In Variable Magnetic Fields, Eric A. Bassett
Theses and Dissertations
The Center for Space Research and Assurance (CSRA) at the Air Force Institute of Technology (AFIT) continues to explore CubeSat initiatives for solving many current space security issues. Regardless of the mission requirements, the success of the Cube- Sat on orbit frequently depends on the Attitude Determination and Control System (ADCS) functioning correctly. Previous research at AFIT has demonstrated single axis control on a spherical air bearing test bed incorporated within a Helmholtz cage utilizing artificially strong magnetic fields for better signal to noise ratios which are not experienced on orbit. This research explores the process of redesigning, testing, and …
Evaluation Of Verification Approaches Applied To A Nonlinear Control System, Kerianne H. Gross
Evaluation Of Verification Approaches Applied To A Nonlinear Control System, Kerianne H. Gross
Theses and Dissertations
As the demand for increasingly complex and autonomous systems grows, designers may consider computational and artificial intelligence methods for more advanced, re- active control. While the performance gained by such increasingly intelligent systems may be superior to traditional control techniques, the lack of transparency in the systems and opportunity for emergent behavior limits their application in the field. New verification and validation methods must be developed to ensure the output of such controllers do not put the system or any people interacting with it in danger. This challenge was highlighted by the former Air Force Chief Scientist in his 2010 …
Vibrational Analysis Of A 12u Chassis, Daniel G. Miller
Vibrational Analysis Of A 12u Chassis, Daniel G. Miller
Theses and Dissertations
The objective of this research is to characterize how the natural frequencies of AFIT’s CubeSat design can be controlled to meet launch vehicle requirements while increasing the internal and external volume available for payload and bus components as the chassis increases in size. A reliable Finite Element (FE) model is created and validated using NASA’s General Environmental Verification Standards (GEVS) vibrational test on the 12U chassis. The validated FE model proves that current boundary conditions and geometric properties with minimized chassis wall thicknesses to maximize usable internal and external volume maintain a first frequency of the fully loaded 12U chassis …