Velocity Plume Profiles For Hall Thrusters Using Laser Diagnostic,
2010
Air Force Institute of Technology
Velocity Plume Profiles For Hall Thrusters Using Laser Diagnostic, Daniel B. Lee
Theses and Dissertations
This research built a non-intrusive laser diagnostic tool using Laser Induced Fluorescence (LIF) and absorption techniques to measure the velocity and density plume profiles of low powered Hall thrusters. This tool was then applied to a Busek 200W Hall thruster to validate the performance against previous research on the same thruster. A laser frequency sweep through 834.72 nm produced LIF signals for ionized xenon –collected at 541.9 nm – in the thruster plume and absorption data outside the plume at a neutral transition at 834.68 nm. The absorption data provided a baseline reference to calculate the axial and radially velocity …
New Space Access Opportunities,
2010
Morehead State University
New Space Access Opportunities, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint presentation created by Professor Bob Twiggs titled "New Space Access Opportunities" May 18, 2010.
A Novel Telescopic Boom Deployment System For Use In Upper Atmosphere Research,
2010
Technological University Dublin
A Novel Telescopic Boom Deployment System For Use In Upper Atmosphere Research, Mark Wylie, Paul Duffy, Dinesh Vather, Johnalan Keegan, Stephen Curran
Conference Papers
Typical measurement probe deployment systems on sounding rockets employ hinged booms which extend the probes away from the rocket. This configuration often has a significant mass and may require a considerable amount of the rocket’s valuable payload volume. In an effort to reduce both mass and volume, the DIT Space Research Group have designed a light weight carbon fibre telescopic boom system, compatible with measurement probes commonly used in upper atmosphere research. Our design has been selected to be tested on a suborbital space flight onboard the REXUS 9 sounding rocket in March 2011. The purpose of this test is …
Programs With Rockets,
2010
Morehead State University
Programs With Rockets, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint presentation created by Professor Bob Twiggs on "Programs with Rockets" from April 5, 2010.
Thrust And Performance Study Of Micro Pulsed Plasma,
2010
Air Force Institute of Technology
Thrust And Performance Study Of Micro Pulsed Plasma, Jeremy J. Selstrom
Theses and Dissertations
This research is focused on several areas of the μPPT performance. An important idea studied is the effect of lifetime use on the performance. The thruster is fired for a simulated lifetime of use to see if there is an impact on the thrust of the thruster later in life. Also vital is the efficiency of the thruster. A μPPT performing at max efficiency will ionize all ablated material; however, we know that not to be the case. In this research the effort is made to collect these non-ionized particles in order to measure their mass post-test. With this collected …
Relative Orbit Elements For Satellites In Elliptical Orbits,
2010
Air Force Institute of Technology
Relative Orbit Elements For Satellites In Elliptical Orbits, Kirk W. Johnson
Theses and Dissertations
The purpose of this research was to describe the unperturbed relative motion of Earth satellites in elliptical orbits using a simple dynamics model whose parameters allow significant geometrical insight and operational efficacy. The goal was to retain the advantages of the Relative Orbit Elements (ROE) realization of the Hill-Clohessy-Wiltshire (HCW) equations, a linearized dynamics model for circular reference orbits. Specifically, this thesis analyzed the geometry of satellite rendezvous and proximity operations using the ROE parameters to characterize the model’s utility. Next, through a comprehensive literature review, this thesis sought possible approaches for developing a similarly useful parameterization for chief orbits …
Accurate Dynamic Response Predictions Of Pnpsat I,
2010
Air Force Institute of Technology
Accurate Dynamic Response Predictions Of Pnpsat I, Michael D. Trottier
Theses and Dissertations
Researchers at the Air Force Institute of Technology (AFIT) and the Operationally Responsive Space (ORS) Office have conducted extensive vibration testing and structural modeling on the first ORS Plug-and-Play Satellite (PnPSAT I). The intent of this research effort is to evaluate the premise that current post-integration spacecraft environmental test requirements can be reduced or modified using accurately tuned finite element (FE) models. As part of this research, modal testing was conducted on the PnPSAT I structural panels at AFIT. The modal testing was part of a much larger series of experimental trials on various configurations of PnPSAT I at the …
Orbit Maneuver For Responsive Coverage Using Electric Propulsion,
2010
Air Force Institute of Technology
Orbit Maneuver For Responsive Coverage Using Electric Propulsion, Timothy S. Hall
Theses and Dissertations
The use of continuous electric propulsion to manipulate a satellite’s orbit offers significant potential for enhancing coverage of a target in ways not previously considered. Elliptical orbits utilizing a very low perigee can facilitate access to the surface and atmosphere of the Earth at sub-ionosphere altitudes while counteracting atmospheric drag forces using continuous electric propulsion. Additionally, in-plane and out-of-plane manipulation of both circular and elliptical orbits can allow for passage of a satellite over a target at a given time. Sustained low perigee orbit was modeled with an initial perigee altitude of 100 km and various apogee altitudes to derive …
Assembly, Integration, And Test Methods For Operationally Responsive Space Satellites,
2010
Air Force Institute of Technology
Assembly, Integration, And Test Methods For Operationally Responsive Space Satellites, Lisa A. Baghal
Theses and Dissertations
Current government and industry standards in spacecraft testing result in an Assembly, Integration, and Test (AIT) timeline greater than six months. These standards will not support the vision of Operationally Responsive Space (ORS) to deploy a satellite within six days to fill an urgent need. Using the Air Force Research Laboratory’s Plug-and-Play Satellite (PnPSat), multiple Rapid AIT trials were conducted. By exercising the AIT process with various spacecraft configurations and personnel, methods for reducing or modifying traditional testing regimen were investigated.
Verification Of Kam Theory On Earth Orbiting Satellites,
2010
Air Force Institute of Technology
Verification Of Kam Theory On Earth Orbiting Satellites, Christian L. Bisher
Theses and Dissertations
This paper uses KAM torus theory and Simplified General Perturbations 4 (SGP4) orbit prediction techniques compiled by Dr. William Wiesel and compares it to Analytical Graphics ® Incorporated (AGI) Satellite Toolkit ® (STK) orbit data. The goal of this paper is to verify KAM torus theory can be used to describe and propagate an Earth satellite orbit with similar accuracy to existing general perturbation techniques. Using SGP4 code including only truncated geopotential effects, KAM torus generating code, and other utilities were used to describe a particular satellite orbit as a torus and then propagate the satellite using traditional and KAM …
Exfit Flight Design And Structural Modeling For Falconlaunch Viii Sounding Rocket,
2010
Air Force Institute of Technology
Exfit Flight Design And Structural Modeling For Falconlaunch Viii Sounding Rocket, Michael J. Vinacco
Theses and Dissertations
This research effort furthers the Air Force’s study of reusable launch vehicles and hypersonic airfoils by conducting a hypersonic flight test using the US Air Force Academy’s FalconLAUNCH VIII sounding rocket. In this study, two experimental fin tips were designed and attached to the sounding rocket in place of two stabilizer fins in order to collect data throughout the rocket’s hypersonic flight profile. The desire to research, study, and test experimental fin tips was driven by the Air Force Research Laboratory’s Future responsive Access to Space Technologies (FAST) program and their desire to include vertical stabilizers on the wing tips …
Cfd Analysis Of Experimental Wing And Winglet For Falconlaunch 8 And The Exfit Program,
2010
Air Force Institute of Technology
Cfd Analysis Of Experimental Wing And Winglet For Falconlaunch 8 And The Exfit Program, Benjamin P. Switzer
Theses and Dissertations
Reusable launch vehicles have many benefits over their expendable counterparts. These benefits range from cost reductions to increased functionality of the vehicles. Further research is required in the development of the technology necessary for reusable launch vehicles to come to fruition. The Air Force Institute of Technology’s future involvement in the ExFIT program will entail designing and testing of a new wing tip mounted vertical stabilizer in the hypersonic regime. One proposed venue for experimentation is to utilize the United States Air Force Academy’s FalconLAUNCH Program which annually designs, builds, and launches a sounding rocket capable of reaching hypersonic speeds. …
Estimating Characteristics Of A Maneuvering Reentry Vehicle Observed By Multiple Sensors,
2010
Air Force Institute of Technology
Estimating Characteristics Of A Maneuvering Reentry Vehicle Observed By Multiple Sensors, Evan M. Brooks
Theses and Dissertations
Post flight analysis of ballistic missile reentry vehicles is an area of focus for the U.S. Government, especially for those involved in ballistic missile defense. Typically, this analysis incorporates either a model-driven least squares filter or a data-following Kalman filter. The research performed here developed a filter that attempts to integrate the strengths of both filters. A least squares filter operates on observation data collected during exoatmospheric free flight and a Kalman filter is used to analyze data collected lower in the atmosphere, where potential maneuvers could be performed. Additionally, the filter was written to incorporate data from multiple sensors. …
Development Of A Remotely Operated Autonomous Satellite Tracking System,
2010
Air Force Institute of Technology
Development Of A Remotely Operated Autonomous Satellite Tracking System, Michael E. Graff
Theses and Dissertations
AFIT is currently developing a capability to remotely and autonomously track LEO satellites using commercial telescopes. Currently, the system is capable of open-loop tracking based on Two-Line Element sets (TLEs) downloaded from NORAD’s space object catalog. The ability to actively track using a closed-loop control system would allow tracking of satellites which deviated from the published TLEs along with providing some information about the object’s new orbital elements. To accomplish closed-loop tracking, the object is imaged by a digital camera connected to a wide field-of-view (WFOV) spotting scope. Software was developed to provide azimuth and elevation inputs in order to …
Analysis Of Slewing And Attitude Determination Requirements For Ctex,
2010
Air Force Institute of Technology
Analysis Of Slewing And Attitude Determination Requirements For Ctex, William J. Starr Jr.
Theses and Dissertations
This thesis examines the slewing and attitude determination requirements for the Chromotomographic Experiment (CTEX), a chromotomographic-based hyperspectral imager, to be mounted on-board the Japanese Experiment Module (JEM) External Facility (EF). The in-track slewing requirement is driven by the facts that CTEx has a very small field of view (FOV) and is required to collect 10 seconds of data for any given collection window. The need to slew in the cross-track direction is a product of the small FOV and target/calibration site access. CTEx incorporates a two-axis slow-steering dwell mirror with a range of ± 8 degrees and an accuracy of …
Minimizing Losses In A Space Laser Power Beaming System,
2010
Air Force Institute of Technology
Minimizing Losses In A Space Laser Power Beaming System, Charlie T. Bellows
Theses and Dissertations
A mathematical model is developed to track the amount of power delivered in a wireless laser power beaming system. In a wireless system the power proceeds through several different stages before being delivered to a payload for use. Each of these stages results in power losses that are thoroughly examined and modeled, allowing for the calculation of the likely amount of power delivered. Adjusting variable factors within the model allows for the optimization of the system for a specific task. The model shows that an optimized wireless power transfer system can deliver enough power to meet the space experiment objectives. …
System Integration And Attitude Control Of A Low-Cost Spacecraft Attitude Dynamics Simulator,
2010
California Polytechnic State University, San Luis Obispo
System Integration And Attitude Control Of A Low-Cost Spacecraft Attitude Dynamics Simulator, Ryan L. Kinnett
Master's Theses
The CalPoly Spacecraft Attitude Dynamics Simulator mimics the rotational dynamics of a spacecraft in orbit and acts as a testbed for spacecraft attitude control system development and demonstration. Prior to this thesis, the simulator platform and several subsystems had been designed and manufactured, but the total simulator system was not yet capable of closed-loop attitude control. Previous attempts to make the system controllable were primarily mired by data transport performance. Rather than exporting data to an external command computer, the strategy implemented in this thesis relies on a compact computer onboard the simulator platform to handle both attitude control processing …
Adaptive Control Applied To The Cal Poly Spacecraft Attitude Dynamics Simulator,
2010
California Polytechnic State University, San Luis Obispo
Adaptive Control Applied To The Cal Poly Spacecraft Attitude Dynamics Simulator, Matthew C. Downs
Master's Theses
The goal of this thesis is to use the Cal Poly Spacecraft Attitude Dynamics Simulator to provide proof of concept of two adaptive control theories developed by former Cal Poly students: Nonlinear Direct Model Reference Adaptive Control and Adaptive Output Feedback Control. The Spacecraft Attitude Dynamics Simulator is a student-built air bearing spacecraft simulator controlled by four reaction wheels in a pyramidal arrangement. Tests were performed to determine the effectiveness of the two adaptive control theories under nominal operating conditions, a “plug-and-play” spacecraft scenario, and under simulated actuator damage. Proof of concept of the adaptive control theories applied to attitude …
Spacecraft Coating-Induced Charging: A Materials And Modeling Study Of Environmental Extreme,
2010
Johns Hopkins University
Spacecraft Coating-Induced Charging: A Materials And Modeling Study Of Environmental Extreme, Michelle M. Donegan, Jennifer L. Sample, John R. Dennison, R. Hoffman
All Physics Faculty Publications
As mankind reaches to explore extreme environments in space, the application of ceramics surface coatings is increasing. The 2005 mission concept for Solar Probe used a unique design to achieve the necessary thermal control for a very close approach to the solar corona, including the use of a highly refractory, electrically insulating ceramic coating over a carbon-carbon composite heat shield. The proposed trajectory takes the spacecraft from a Jovian fly-by to within 4 solar radii of the Sun, spanning 5 orders of magnitude in solar radiation and solar wind plasma density as well as spacecraft temperatures from <100 K to >2000 K. Using …
Exomedicine Synthesis Paper,
2010
Morehead State University
Exomedicine Synthesis Paper, Rita Briggs
Robert "Bob" Twiggs STEM Education Collection
A report by Rita Briggs titled "Exomedicine Synthesis Paper" from 2010.
