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Full-Text Articles in Engineering

Cubesat Constellation Analysis For Data Relaying, Bradley Ryan Smalarz Dec 2011

Cubesat Constellation Analysis For Data Relaying, Bradley Ryan Smalarz

Master's Theses

Current CubeSat communication technology limits the amount of time, and number of accesses with ground stations. It has been proposed to use a constellation of CubeSats to improve relay performance and increase the number of accesses between a CubeSat and ground stations. By using the spatial and temporal analysis features of STK, coupled with the STK/Matlab interface a robust tool was created to analyze the performance of CubeSat constellations based on a store-and-forward communications model which is not currently supported by the STK Engine. Utilizing the Connect messaging format through a socket connection on the local machine, a Matlab graphical …


Particle Shielding For Human Spaceflight: Electrostatic Potential Effects On The Störmer Magnetic Dipole Exclusion Region, Benjamin Alan Klamm Dec 2011

Particle Shielding For Human Spaceflight: Electrostatic Potential Effects On The Störmer Magnetic Dipole Exclusion Region, Benjamin Alan Klamm

Masters Theses

A basic hybrid radiation shield concept, consisting of both a monopole positive electrostatic potential barrier and a current-carrying superconducting solenoid, was predicted to provide a more effective method of shielding a habitable torus region than a solenoid acting alone. A randomized position and velocity vector simulation of equal-energy iron ions using a Lagrangian reference frame was performed on the exact magnetic field integral for the solenoid and a discrete summation electrostatic field for a toroidal monopole array approximating a potential surface. Each particle is injected at a specific energy (100, 150 MeV and 1 GeV). Two cases were evaluated at …


Performance Analysis Of A Variable Conductance Heat Pipe, Herron Arreola Oct 2011

Performance Analysis Of A Variable Conductance Heat Pipe, Herron Arreola

Aerospace Engineering

This report examines the analysis of a donated Boeing variable conductance heat pipe with unknown performance characteristics. These characteristics were found through experimental means by utilizing 14 thermocouples attached to various locations on the heat pipe, the heaters and to the insulation. Although the maximum axial heat transport capability could not be determined due to the limited number of strip heaters available, the maximum radial heat flux capability of the heat pipe was found to be 2.46 W/in2. The experiment also revealed that increasing the input power decreased the burn out inclination angle and that using a coolant …


A Feasibility Study For Using Commercial Off The Shelf (Cots) Hardware For Meeting Nasa’S Need For A Commercial Orbital Transportation Services (Cots) To The International Space Station - [Cots]2, Chad Lee Davis Aug 2011

A Feasibility Study For Using Commercial Off The Shelf (Cots) Hardware For Meeting Nasa’S Need For A Commercial Orbital Transportation Services (Cots) To The International Space Station - [Cots]2, Chad Lee Davis

Masters Theses

The space vehicle system concept (i.e. resupply vehicle) described is based on the new direction that President George W. Bush announced on January 14, 2004 for NASA’s Human Exploration, which has the space shuttle retiring in 2011 following the completion of the International Space Station (ISS). This leads to a problem for the ISS community regarding the capability of meeting a sixty metric-ton cargo shortfall in resupply and the ability of returning large payloads, experiment racks and any other items too large to fit into a crew only type spacecraft like the Orion or Soyuz. NASA and the ISS partners …


Thermal Analysis Of The Cubesat Cp3 Satellite, Jonas Friedel, Sean Mckibbon Jun 2011

Thermal Analysis Of The Cubesat Cp3 Satellite, Jonas Friedel, Sean Mckibbon

Aerospace Engineering

Due to inconsistencies found in the on-orbit thermal data from the CubeSat CP3 satellite between 2007 and 2011, further analysis is performed on a larger number of data from August 2010 through April 2011, aiming to find an explanation for the overall increasing measured temperatures and shortening peak periods. Therefore, the satellite power data as well as orbital anomalies are analyzed leading to the conclusion that the satellite was temporarily (January – March 2011) orbiting with significantly increased sun exposure causing the higher temperatures. The shortened temperature peak periods are explained by alternating albedo values as the main influence in …


An Analysis Of Stabilizing 3u Cubesats Using Gravity Gradient Techniques And A Low Power Reaction Wheel, Erich Bender Jun 2011

An Analysis Of Stabilizing 3u Cubesats Using Gravity Gradient Techniques And A Low Power Reaction Wheel, Erich Bender

Aerospace Engineering

The purpose of this paper is to determine the feasibility of gravity gradient stabilizing a 3U CubeSat and then using a miniature reaction wheel to further increase stability characteristics. This paper also serves as a guide to understanding and utilizing quaternions in attitude control analysis. The analytical results show that using 33 centimeter booms and 400 gram tip masses, a 3U CubeSat will experience a maximum of 6 degrees of angular displacement in yaw and pitch, and less than .5 degrees of angular displacement in the nadir axis. A .120 kilogram miniature reaction wheel developed by Sinclair Interplanetary was introduced …


Design, Manufacturing And Testing Of An Environmentally-Green Bipropellant Thruster, Alex Bendoyro, Gabriel Sanchez, Erin Stearns, Phillip Takahashi Jun 2011

Design, Manufacturing And Testing Of An Environmentally-Green Bipropellant Thruster, Alex Bendoyro, Gabriel Sanchez, Erin Stearns, Phillip Takahashi

Aerospace Engineering

This project reviews the design, manufacturing and experimentation process of a green bi-propellant thruster designed to output 5 lbf. The goals were to successfully design, manufacture and test a thruster, while discovering the complications that arise through out the complete design process of a green thruster. The thruster was successfully designed using ideal rocket equations and the design was successfully confirmed using CFD and FEA. Manufacturing of the thruster was fully planned and revealed mild flaws in thruster design. For example some features were not manufacturable to the exact measurements desired. Testing of the engine gave results inconsistent with expected …


Design, Fabrication, And Testing Of An Electromagnetic Rail Gun For The Repeated Testing And Simulation Of Orbital Debris Impacts, Jeff Maniglia, Jordan Smiroldo, Alex Westfall, Guy Zohar Jun 2011

Design, Fabrication, And Testing Of An Electromagnetic Rail Gun For The Repeated Testing And Simulation Of Orbital Debris Impacts, Jeff Maniglia, Jordan Smiroldo, Alex Westfall, Guy Zohar

Aerospace Engineering

An Electromagnetic Railgun (EMRG) was designed, built, and tested, capable of firing a projectile a 1 gram projectile at 650 m/s muzzle velocity. The EMRG utilizes an injector, a high voltage power supply, a capacitor bank, inductors and rails. The injector fires 2300 psig Nitrogen gas into the system to provide an initial velocity. The high voltage power supply charges the capacitor bank. The capacitor bank discharges the electric potential built up through the projectile while inside the rails in order to create the EMRG’s force. The inductors are used to pulse form the capacitor bank in order to get …


Development Of A Cubesat Instrument For Microgravity Particle Damper Performance Analysis, John Trevor Abel Jun 2011

Development Of A Cubesat Instrument For Microgravity Particle Damper Performance Analysis, John Trevor Abel

Master's Theses

Spacecraft pointing accuracy and structural longevity requirements often necessitate auxiliary vibration dissipation mechanisms. However, temperature sensitivity and material degradation limit the effectiveness of traditional damping techniques in space. Robust particle damping technology offers a potential solution, driving the need for microgravity characterization. A 1U cubesat satellite presents a low cost, low risk platform for the acquisition of data needed for this evaluation, but severely restricts available mass, volume, power and bandwidth resources. This paper details the development of an instrument subject to these constraints that is capable of capturing high resolution frequency response measurements of highly nonlinear particle damper dynamics.


Vortex Driven Acoustic Flow Instability, Lutz Blaette May 2011

Vortex Driven Acoustic Flow Instability, Lutz Blaette

Doctoral Dissertations

Most combustion machines feature internal flows with very high energy densities. If a small fraction of the total energy contained in the flow is diverted into oscillations, large mechanical or thermal loads on the structure can be the result, which are potentially devastating if not predicted correctly. This is particularly the case for lightweight high performing devices like rockets. The problem is commonly known as "Combustion Instability".
Several mechanisms have been identified in the past that link the flow field to the acoustics inside a combustion chamber and thereby drive or dampen oscillations, one of them being vortex shedding.

The …


Development Of A Laboratory Experiment To Simulate Upper-Stage Rocket Explosions, Timothy J. Price May 2011

Development Of A Laboratory Experiment To Simulate Upper-Stage Rocket Explosions, Timothy J. Price

Aerospace Engineering

This report is a summary of the senior project entitled Development of a Laboratory Experiment to Simulate Upper-Stage Rocket Explosions. The goal of the experiment was to recreate a NASA experiment which used aluminum soft drink cans to approximate the shape of an Ariane third stage rocket. The cans were placed in a vacuum chamber and fired upon with a projectile from a light gas gun. The resulting debris was collected and analyzed allowing several conclusions to be made regarding the behavior or rocket breakups and the formation of space debris. In lieu of a light gas gun, energy drink …


Development And Analysis Of Onboard Translunar Injection Targeting Algorithms, Phillippe Lyles Winters Reed May 2011

Development And Analysis Of Onboard Translunar Injection Targeting Algorithms, Phillippe Lyles Winters Reed

Masters Theses

Several targeting algorithms are developed and analyzed for possible future use onboard a spacecraft. Each targeter is designed to determine the appropriate propulsive burn for translunar injection to obtain desired orbital parameters upon arrival at the moon. Primary design objectives are to minimize the computational requirements for each algorithm but also to ensure reasonable accuracy, so that the algorithm’s errors do not force the craft to conduct large mid-course corrections. Several levels of accuracy for dynamical models are explored, the convergence range and speed of each algorithm are compared, and the possible benefits of the Broyden and trust-region targeters are …


Preliminary Design Of An Asteroid Hopping Mission, Michael D. Scheppa Apr 2011

Preliminary Design Of An Asteroid Hopping Mission, Michael D. Scheppa

Doctoral Dissertations and Master's Theses

In 2010, NASA announced that its new vision is to support private space launch operations. It is anticipated that this new direction will create the need for new and innovative ideas that push the current boundaries of space exploration and contain the promise of substantial gain, both in research and capital.

The purpose of the study is to plan and estimate the feasibility of a mission to visit a number of near Earth asteroids (NEAs). The mission would take place before the end of the 21st century, and would only use commercially available technology. Throughout the mission design process, while …


Using A Gatling-Gun Configured Micro Pulsed Plasma Thruster As A Means To Control Micro Satellites With Extreme Precision, Lee I. Watson Mar 2011

Using A Gatling-Gun Configured Micro Pulsed Plasma Thruster As A Means To Control Micro Satellites With Extreme Precision, Lee I. Watson

Theses and Dissertations

Micro-Pulsed Plasma Thrusters (µPPT) are becoming increasingly attractive for their low power consumption and moderately high specific impulse in the range of 800-1200s. The Gatling Gun micro-Pulsed Plasma Thruster (GG-µPPT) is a new device offering reduced mass and higher thrust than single µPPTs and solid application in precise pointing and orbit maintenance applications. The performance of µPPTs depends on frequency and applied voltage/power levels. Variation of these input parameters and effects on operation and performance of this thruster system were the focus of this research. Contamination aspects were also considered and discussed, since the buildup of carbon results in decreased …


Enhancing Cnt-Composites With Raman Spectroscopy, Gregory J. Freihofer Jan 2011

Enhancing Cnt-Composites With Raman Spectroscopy, Gregory J. Freihofer

Electronic Theses and Dissertations

Carbon Nanotubes (CNTs) have been the subject of intense research for their potential to improve a variety of material properties when developed as nano-composites. This research aims to address the challenges that limit the ability to transfer the outstanding nano-scale properties of CNTs to bulk nano-composites through Raman characterization. These studies relate the vibrational modes to microstructural characterization of CNT composites including stress, interface behavior, and defects. The formulation of a new fitting procedure using the pseudo-Voigt function is presented and shown to minimize the uncertainty of characteristics within the Raman G and D doublet. Methods for optimization of manufacturing …


Thermomechanical Behavior Of High-Temperature Shape Memory Alloy Ni-Ti-Pd-Pt Actuators, Douglas E. Nicholson Jan 2011

Thermomechanical Behavior Of High-Temperature Shape Memory Alloy Ni-Ti-Pd-Pt Actuators, Douglas E. Nicholson

Electronic Theses and Dissertations

To date the commercial use of shape memory alloys (SMAs) has been mostly limited to binary NiTi alloys with transformation temperatures approximately in the -100 to 100 ºC range. In an ongoing effort to develop high-temperature shape memory alloys (HTSMAs), ternary and quaternary additions are being made to binary NiTi to form NiTi-X (e.g., X: Pd, Pt, Au and Hf) alloys. Stability and repeatability can be further increased at these higher temperatures by limiting the stress, but the tradeoff is reduced work output and stroke. However, HTSMAs operating at decreased stresses can still be used effectively in actuator applications that …


Optimal Attitude Control Management For A Cubesat, Michael James Develle Jan 2011

Optimal Attitude Control Management For A Cubesat, Michael James Develle

Electronic Theses and Dissertations

CubeSats have become popular among universities, research organizations, and government agencies due to their low cost, small size, and light weight. Their standardized configurations further reduce the development time and ensure more frequent launch opportunities. Early cubesat missions focused on hardware validation and simple communication missions, with little requirement for pointing accuracy. Most of these used magnetic torque rods or coils for attitude stabilization. However, the intrinsic problems associated with magnetic torque systems, such as the lack of three-axis control and low pointing accuracy, make them unsuitable for more advanced missions such as detailed imaging and on-orbit inspection. Threeaxis control …