Engineering Commons^™

Low-Cost Reaction Wheel Design For Cubesat Applications, Nicholas J. Bonafede Jr.

Master's Theses

As science instruments on CubeSats become more sensitive to the attitude of the spacecraft, better methods must be employed to provide the accuracy needed to complete the planned mission. While systems that provide the accuracy required are available commercially, these solutions are not cost-effective, do not allow the design to be tailored to a specific mission, and most importantly, do not give students hand-on experience with attitude control actuators. This thesis documents the design, modeling, and simulation of a low-cost, student-fabricated, reaction wheel system for use in 3U CubeSat satellites. The entire design process for the development of this reaction …

Polysat Helmholtz Cage, Alex Nichols, Nicolas Le Renard, Jordan Skaro, Louie Thiros, Madeline Tran

Mechanical Engineering

The MagCal5 Helmholtz cage project is an interdisciplinary approach to provide the PolySat/CubeSat research lab with a magnetic testing environment for the calibration of magnetic components and verification of various control laws. The Cal Poly CubeSat organization is the home of the CubeSat Specification, and acts as a testing and integration facility for CubeSats built by universities across the world. The PolySat organization is a CubeSat developer that works with numerous industry partners to design, manufacture, and operate CubeSats to further scientific advancement. The addition of a magnetic test stand to the lab will allow CubeSat to extend to the …

Ism S-Band Cubesat Radio Designed For The Polysat System Board, Craig Lee Francis

Master's Theses

Cal Poly’s PolySat CubeSat satellites have begun to conduct more complex and scientifically significant experiments. The large data products generated by these missions demonstrate the necessity for higher data rate communication than currently provided by the PolySat UHF radio. This thesis leverages the proliferation of consumer wireless monolithic transceivers to develop a 250kbps to 2000kbps, 2W CubeSat radio operating within the 2.45GHz Industrial, Scientific, and Medical (ISM) radio band.

Estimating a link budget for a realistic CubeSat leads to the conclusion that this system will require a large deployable CubeSat antenna, large earth station satellite dish, and a fine-pointing attitude …

Development Of Tools Needed For Radiation Analysis Of A Cubesat Deployer Using Oltaris, Marycarmen Gonzalez-Dorbecker

Master's Theses

Currently, the CubeSat spacecraft is predominantly used for missions at Low- Earth Orbit (LEO). There are various limitations to expanding past that range, one of the major ones being the lack of sufficient radiation shielding on the Poly-Picosatellite Orbital Deployer (P-POD). The P-POD attaches to a launch vehicle transporting a primary spacecraft and takes the CubeSats out into their orbit. As the demand for interplanetary exploration grows, there is an equal increase in interest in sending CubeSats further out past their current regime. In a collaboration with NASA’s Jet Propulsion Laboratory (JPL), students from the Cal Poly CubeSat program worked …

Tesseract, Edgar Uribe, Vanessa Faune

Mechanical Engineering

PolySat is a student-run, Cal Poly research program in which students develop small satellites, known as CubeSats, to be sent into space. Since the start of the program in 2000, PolySat has developed eight 10cm x 10cm x10cm CubeSats. Recently, the team has developed two satellites of double, and triple, that size for NASA-KSC & AI-Solutions and the National Science Foundation. The recent volumetric expansion has been driven by high demand for further satellite functionality, which necessitates large power generation capabilities. To remain competitive in the growing CubeSat industry, PolySat must develop a platform that can provide enough power to …

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 …

Radio Link Analysis And Characterization Of Past And Future Cal Poly Cubesats, Brian Gilbert Tubb

Electrical Engineering

Cal Poly's satellites design team, PolySat, has three satellites in Low Earth Orbit (LEO) and four more planned to launch within the next two years. Radio communication of past and current orbiting satellites has been an exercise in frustration, prompting significant research into the satellite-side of the radio link by several other Senior Projects and Thesis papers. However, minimal effort has been spent on evaluating why these problems were discovered only once the satellites reached orbit. This paper details the downfalls of relying heavily on link budgets and improper long range test setups, then experimentally determines the sensitivity of PolySat's …

Reliable Software Updates For On-Orbit Cubesat Satellites, Sean Fitzsimmons

Master's Theses

CubeSat satellites have redefined the standard solution for conducting missions in space due to their unique form factor and cost. The harsh environment of space necessitates examining features that improve satellite robustness and ultimately extend lifetime, which is typical and vital for mission success. The CubeSat development team at Cal Poly, PolySat, has recently redefined its standard avionics platform to support more complex mission capabilities with this robustness in mind. A significant addition was the integration of the Linux operating system, which provides the flexibility to develop much more elaborate protection mechanisms within software, such as support for remote on-orbit …

Datalogger Sequence Execution Engine (Dsqee), Edmund Yingxiang Yee

Computer Engineering

The PolySat Research Group accepts projects from several companies that wish to use a CubeSat for some experiment. One of the projects called Intelligent Payload Experiment, or IPEX, needs software to interact with out system avionics. One of these software will be datalogger, which will be augmented from its original datalogging scheme to support sequentially execution of commands/algorithms that our client, Jet Propulsion Laboratory, or JPL, need. My part of the project explains the software design decisions behind datalogger.

Cp7 And Datalogger Design And Implementation, Hoang (Mike) Tran

Computer Engineering

No abstract provided.

Boom Stability Control Final Project Report, Michael Barnes, Justin Carnahan, Daniel Fluitt, Alicia Johnstone

Mechanical Engineering

The BOOMStiC Gravity Gradient Boom and Turnstile Antenna project was developed to provide a passive attitude control system and better communications for future CubeSat satellites developed by California Polytechnic State University. The system utilizes the energy from a coilable metal spring to deploy a tip mass to a length of one meter from the side of the satellite. Calculations show the resulting gravity gradient torque causes to the satellite to settle two degrees from normal to the earth’s surface.

The Next Generation Cubesat: A Modular And Adaptable Cubesat Frame Design, James Dolengewicz, Lucas Whipple, Stephanie Wong

Mechanical Engineering

The goal of this project is to develop an improved next-generation CubeSat structure for Cal Poly’s PolySat program. Notable achievements include significantly increased ease of access, design to optimize payload space, improved machinability, increased modularity and a platform which allows for easy integration of future payloads.

Receive Sensitivity Characterization Of The Polysat Satellite Communication System, Ivan M. Bland

Master's Theses

Following the successful launch of CP3 and CP4, the PolySat team noticed an unreliable uplink to both satellites. A significant problem with the PolySat COMM system is poor receive sensitivity of the communications system. Efforts have been made to improve the uplink margin, but without proper characterization of the receiver sensitivity, the problem cannot be fully addressed. By developing an accurate method of measuring receive sensitivity, a methodical approach can be used to properly diagnose the communication system and link budget. Two revisions of the PolySat COMM system will be measured and compared. An in-depth study of the PolySat COMM …