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Articles 1 - 16 of 16

Full-Text Articles in Engineering

Analysis Of An Inflatable Gossamer Device To Efficiently De-Orbit Cubesats, Robert A. Hawkins Jr. Dec 2013

Analysis Of An Inflatable Gossamer Device To Efficiently De-Orbit Cubesats, Robert A. Hawkins Jr.

Master's Theses

There is an increased need for spacecraft to quickly and efficiently de-orbit themselves as the amount of debris in orbit around Earth grows. Defunct spacecraft pose a significant threat to the LEO environment due to their risk of fragmentation. If these spacecraft are de-orbited at the end of their useful life their risk to future spacecraft is greatly lessened. A proposed method of efficiently de-orbiting spacecraft is to use an inflatable thin-film envelope to increase the body's area to mass ratio and thusly shortening its orbital lifetime. The system and analysis presented in this project is sized for use on …


Feasibility Of Cubesat Formation Flight Using Rotation To Achieve Differential Drag, Skyler M. Shuford Jun 2013

Feasibility Of Cubesat Formation Flight Using Rotation To Achieve Differential Drag, Skyler M. Shuford

Aerospace Engineering

This paper presents the results of a study conducted to understand the feasibility of CubeSat formation flight. The mechanism for separation and formation studied was differential drag, achieved by rotating the CubeSats to give them different cross-sectional areas. Intuitively, lower altitude orbits provide much higher separation effects. Although the most influential orbital effects occur with maximum and minimum cross-sectional areas, an attitude-controlled and a tumbling CubeSat may provide enough differential drag to meet separation requirements of a mission. Formation flight is possible, but due to the non-linearity of the system, gain scheduling may be the most effective method of long …


Rocket Fuel Pressurization, Sean Green, Joe Marcinkowski, Andrew Nahab Jun 2013

Rocket Fuel Pressurization, Sean Green, Joe Marcinkowski, Andrew Nahab

Mechanical Engineering

No abstract provided.


Design, Fabrication, And Testing Of An Emr Based Orbital Debris Impact Testing Platform, Jeffrey J. Maniglia Jr. Jun 2013

Design, Fabrication, And Testing Of An Emr Based Orbital Debris Impact Testing Platform, Jeffrey J. Maniglia Jr.

Master's Theses

This paper describes the changes made from Cal Poly’s initial railgun system, the Mk. 1 railgun, to the Mk. 1.1 system, as well as the design, fabrication, and testing of a newer and larger Mk. 2 railgun system. The Mk. 1.1 system is developed as a more efficient alteration of the original Mk. 1 system, but is found to be defective due to hardware deficiencies and failure, as well as unforeseen efficiency losses. A Mk. 2 system is developed and built around donated hardware from the Naval Postgraduate School. The Mk. 2 system strove to implement an efficient, augmented, electromagnetic …


Assessment For Completion Of Cp7 Integration With Revision 6 Avionics, Daniel Jennings Jun 2013

Assessment For Completion Of Cp7 Integration With Revision 6 Avionics, Daniel Jennings

Electrical Engineering

he purpose of this project is the continuation of the CP7 CubeSat project, analysis for integration with new Avionics Systems, and to leave behind instruction for future work for completion of the satellite. CP7 is a satellite in development to support a mechanical and electrical system to experiment on particle damping in micro-gravity. The completion of this satellite needs to be prioritized more than it has been by the PolySat team to honor our work with Northrop Grumman, who have been supportive and helpful throughout the process. This work seeks to aid in the completion of this satellite, so that …


A Generic Decision Making Framework For Autonomous Systems, Connor Lange Jun 2013

A Generic Decision Making Framework For Autonomous Systems, Connor Lange

Master's Theses

With the rising popularity of small satellites, such as CubeSats, many smaller institutions previously incapable of developing and deploying a spacecraft have starting to do so. Institutions with a history of space flight, such as NASA JPL, have begun to put projects on CubeSats that would normally fly on much larger satellites. As a result, the institutions with space flight heritage have begun to port spacecraft software that was previously designed for much larger and more complex satellites to the CubeSat platform. Unfortunately for universities, who are the majority of all institutions devel- oping CubeSats, these ported systems are too …


Characterization Of The Effects Of A Sun-Synchronous Orbit Slot Architecture On The Earth's Orbital Debris Environment, Connor David Noyes Jun 2013

Characterization Of The Effects Of A Sun-Synchronous Orbit Slot Architecture On The Earth's Orbital Debris Environment, Connor David Noyes

Master's Theses

Low Earth orbit represents a valuable limited natural resource. Of particular interest are sun-synchronous orbits; it is estimated that approximately 44% of low Earth satellites are sun-synchronous. A previously developed sun-synchronous orbit slot architecture is considered. An in-depth analysis of the relative motion between satellites and their corresponding slots is performed. The long-term evolution of Earth's orbital environment is modeled by a set of coupled ordinary differential equations. A metric for quantifying the benefit, if any, of implementing a sun-synchronous architecture is developed. The results indicate that the proposed slot architecture would reduce the frequency of collisions between satellites in …


Feasibility Of Microsatellite Active Debris Removal Systems, Karsten J. James Jun 2013

Feasibility Of Microsatellite Active Debris Removal Systems, Karsten J. James

Master's Theses

Space debris has become an increasingly hazardous obstacle to continued spaceflight operations. In an effort to mitigate this problem an investigation of the feasibility of a microsatellite active debris removal system was conducted. Through proposing a novel concept of operation, utilizing a grapple-and-tug system architecture, and by analyzing each resultant mission phase in the frame of a representative example, it was found that microsatellite scale systems are capable of fulfilling the active debris removal mission. Analysis of rendezvous, docking, control and deorbit mission requirements determined that the design of a grapple-and-tug system will be driven by sizing of the propellant …


Investigation Of A Lagrangian-Point Propellant Depot Rendezvous Approach For An Interplanetary Mission To Mars, Joshua W. Ehrlich May 2013

Investigation Of A Lagrangian-Point Propellant Depot Rendezvous Approach For An Interplanetary Mission To Mars, Joshua W. Ehrlich

Doctoral Dissertations and Master's Theses

This thesis investigates the feasibility of a refueling station for a beyond Earth orbit (BEO) mission. The propellant depot is located at the L2 -Lagrangian point within the Earth-Moon system. This investigation determines if a refueling mission will reduce propulsive energy requirements necessary for Earth departure of a BEO-vehicle to achieve an interplanetary transfer to Mars. Furthermore, this research presents a trade study which identifies approximate total requirements for a direct and rendezvous mission to Mars as well as the necessary fuel masses to complete each approach. This analysis provides conclusive information in determining the benefits in utilizing a …


Design Of Economical Upper Stage Hybrid Rocket Engine, Christopher R. Potter May 2013

Design Of Economical Upper Stage Hybrid Rocket Engine, Christopher R. Potter

Chancellor’s Honors Program Projects

No abstract provided.


Ad-Hoc Regional Coverage Constellations Of Cubesats Using Secondary Launches, Guy G. Zohar Mar 2013

Ad-Hoc Regional Coverage Constellations Of Cubesats Using Secondary Launches, Guy G. Zohar

Master's Theses

As development of CubeSat based architectures increase, methods of deploying constellations of CubeSats are required to increase functionality of future systems. Given their low cost and quickly increasing launch opportunities, large numbers of CubeSats can easily be developed and deployed in orbit. However, as secondary payloads, CubeSats are severely limited in their options for deployment into appropriate constellation geometries.

This thesis examines the current methods for deploying cubes and proposes new and efficient geometries using secondary launch opportunities. Due to the current deployment hardware architecture, only the use of different launch opportunities, deployment direction, and deployment timing for individual cubes …


Bio-Inspired Cooperative Optimal Trajectory Planning For Autonomous Vehicles, Charles Remeikas Jan 2013

Bio-Inspired Cooperative Optimal Trajectory Planning For Autonomous Vehicles, Charles Remeikas

Electronic Theses and Dissertations

With the recent trend for systems to be more and more autonomous, there is a growing need for cooperative trajectory planning. Applications that can be considered as cooperative systems such as surveying, formation flight, and traffic control need a method that can rapidly produce trajectories while considering all of the constraints on the system. Currently most of the existing methods to handle cooperative control are based around either simple dynamics and/or on the assumption that all vehicles have homogeneous properties. In reality, typical autonomous systems will have heterogeneous, nonlinear dynamics while also being subject to extreme constraints on certain state …


Vision-Based Sensing And Optimal Control For Low-Cost And Small Satellite Platforms, Bradley Sease Jan 2013

Vision-Based Sensing And Optimal Control For Low-Cost And Small Satellite Platforms, Bradley Sease

Electronic Theses and Dissertations

Current trends in spacecraft are leading to smaller, more inexpensive options whenever possible. This shift has been primarily pursued for the opportunity to open a new frontier for technologies with a small financial obligation. Limited power, processing, pointing, and communication capabilities are all common issues which must be considered when miniaturizing systems and implementing low-cost components. This thesis addresses some of these concerns by applying two methods, in attitude estimation and control. Additionally, these methods are not restricted to only small, inexpensive satellites, but offer a benefit to large-scale spacecraft as well. First, star cameras are examined for the tendency …


Mission Analysis For Pico-Scale Satellite Based Dust Detection In Low Earth Orbits, Jacob Belli Jan 2013

Mission Analysis For Pico-Scale Satellite Based Dust Detection In Low Earth Orbits, Jacob Belli

Electronic Theses and Dissertations

A conceptual dust detection mission, KnightSat III, using pico-scale satellites is analyzed. The purpose of the proposed KnightSat III mission is to aid in the determination of the size, mass, distribution, and number of dust particles in low earth orbits through a low cost and flexible satellite or a formation of satellites equipped with a new dust detector. The analysis of a single satellite mission with an on-board dust detector is described; though this analysis can easily be extended to a formation of pico-scale satellites. Many design aspects of the mission are discussed, including orbit analysis, power management, attitude determination …


An Attitude Determination System With Mems Gyroscope Drift Compensation For Small Satellites, Maxwell Bezold Jan 2013

An Attitude Determination System With Mems Gyroscope Drift Compensation For Small Satellites, Maxwell Bezold

Theses and Dissertations--Electrical and Computer Engineering

This thesis presents the design of an attitude determination system for small satellites that automatically corrects for attitude drift. Existing attitude determination systems suffer from attitude drift due to the integration of noisy rate gyro sensors used to measure the change in attitude. This attitude drift leads to a gradual loss in attitude knowledge, as error between the estimated attitude and the actual attitude increases.

In this thesis a Kalman filter is used to complete sensor fusion which combines sensor observations with a projected attitude based on the dynamics of the satellite. The system proposed in this thesis also utilizes …


Visual Attitude Propagation For Small Satellites, Samir Ahmed Rawashdeh Jan 2013

Visual Attitude Propagation For Small Satellites, Samir Ahmed Rawashdeh

Theses and Dissertations--Electrical and Computer Engineering

As electronics become smaller and more capable, it has become possible to conduct meaningful and sophisticated satellite missions in a small form factor. However, the capability of small satellites and the range of possible applications are limited by the capabilities of several technologies, including attitude determination and control systems. This dissertation evaluates the use of image-based visual attitude propagation as a compliment or alternative to other attitude determination technologies that are suitable for miniature satellites. The concept lies in using miniature cameras to track image features across frames and extracting the underlying rotation.

The problem of visual attitude propagation as …