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Erlank, Alexander Olaf. "Development of CubeStar : a CubeSat-compatible star tracker." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/85746.
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Thesis (MEng)-- Stellenbosch University, 2013.<br>ENGLISH ABSTRACT: The next generation of CubeSats will require accurate attitude knowledge throughout
orbit for advanced science payloads and high gain antennas. A star tracker can
provide the required performance, but star trackers have traditionally been too large,
expensive and power hungry to be included on a CubeSat. The aim of this project
is to develop and demonstrate a CubeSat compatible star tracker. Subsystems from
two other CubeSat components, CubeSense and CubeComputer, were combined with
a sensitive, commercial image sensor and low-light lens to produce one of the smallest
star trackers in existence. Algorithms for star detection, matching and attitude determination
were investigated and implemented on the embedded system. The resultant
star tracker, named CubeStar, can operate fully autonomously, outputting attitude
estimates at a rate of 1 Hz. An engineering model was completed and demonstrated
an accuracy of better than 0.01 degrees during night sky tests.<br>AFRIKAANSE OPSOMMING: Die volgende generasie van CubeSats sal akkurate orientasie kennis vereis gedurende
'n volle omwentelling van die aarde. 'n Sterkamera kan die vereiste prestasie verskaf,
maar sterkameras is tradisioneel te groot, duur en krag intensief om ingesluit te word
aanboord 'n CubeSat. Die doel van hierdie projek is om 'n CubeSat sterkamera te ontwikkel
en te demonstreer. Substelsels van twee ander CubeSat komponente, CubeSense
en CubeComputer, was gekombineer met 'n sensitiewe kommersiële beeldsensor en 'n
lae-lig lens om een van die kleinste sterkameras op die mark te produseer. Algoritmes
vir die ster opsporing, identi kasie en orientasie bepaling is ondersoek en geïmplementeer
op die ingebedde stelsel. Die gevolglike sterkamera, genaamd CubeStar, kan ten
volle outonoom orientasie afskattings lewer teen 'n tempo van 1 Hz. 'n Ingenieursmodel
is voltooi en 'n akkuraatheid van beter as 0.01 grade is gedemonstreer.
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Slettebo, Christian. "CubeSub : A CUBESAT BASED SUBMERSIBLE TESTBED FOR SPACE TECHNOLOGY." Thesis, KTH, Flygdynamik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-198521.
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This report is a Master’s Thesis in Aerospace Engineering, performed at the NASA Ames Research Center. It describes the development of the CubeSub, a submersible testbed compatible with the CubeSat form factor. The CubeSub will be used to mature technology and operational procedures to be used in space exploration, and possibly also as a tool for exploration of Earthly environments. CubeSats are carried as payloads, either containing technology to be tested or experiments and sensors for scientific use. The CubeSub is designed to be built up by modules, which can be assembled in different configurations to fulfill different needs. Each module is powered individually and intermodular communication is wireless, reducing the need for wiring. The inside of the hull is flooded with ambient water to simplify the interaction between payloads and surrounding environment. The overall torpedo-like shape is similar to that of a conventional AUV, slender and smooth. This is to make for a low drag, reduce the risk of snagging on surrounding objects and make it possible to deploy through an ice sheet via a narrow borehole. Rapid prototyping is utilized wherever possible. Full-scale prototypes have been constructed through 3D-printing and using COTS (Commercial Off-The-Shelf) components. Arduino boards are used for control and internal communication. Modules required for basic operation have been designed, manufactured and tested. Each module is described with regards to its function, design and manufacturability. By performing tests in a pool it was found that the basic concept is sound and that future improvements include better controllability, course stability and waterproofing of electrical components. Further development is needed to make the CubeSub usable for its intended purposes. The largest gains are expected to be found by developing the software and improving controllability.
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castello, brian. "CUBESAT MISSION PLANNING TOOLBOX." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/787.
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We are in an era of massive spending cuts in educational institutions, aerospace companies and governmental entities. Educational institutions are pursuing more training for less money, aerospace companies are reducing the cost of gaining ight heritage and the government is cutting budgets and their response times. Organizations are accomplishing this improved efficiency by moving away from large-scale satellite projects and developing pico and nanosatellites following the CubeSat specifications. One of the major challenges of developing satellites to the standard CubeSat mission requirements is meeting the exceedingly tight power, data and communication constraints.
A MATLAB toolbox was created to assist the CubeSat community with understanding these restrictions, optimizing their systems, increasing mission success and decreasing the time building to these initial requirements. The Toolbox incorporated the lessons learned from the past nine years of CubeSats' successes and Analytical Graphics, Inc. (AGI)'s Satellite Tool Kit (STK). The CubeSat Mission Planning Toolbox (CMPT) provides graphical representations of the important requirements a systems engineer needs to plan their mission. This includes requirements for data storage, ground station facilities, orbital parameters, and power. CMPT also allows for a comparison of broadcast (BC) downlinking to Ground Station Initiated (GSI) downlinking for payload data using federated ground station networks. Ultimately, this tool saves time and money for the CubeSat systems engineer
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Tapparel, Pierre-André. "CDMS pour cubesat /." Sion, 2006. http://doc.rero.ch/search.py?recid=8376&ln=fr.
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Horký, Jan. "Řídicí jednotka pro CubeSat." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-318165.
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Cílem práce je návrh univerzální řídicí jednotky pro CubeSat založené na obvodu FPGA. Taková jednotka doposud nebyla komerčně dostupná a navržená jednotka má tak dobrý potenciál zaplnit příslušné místo na trhu komponent pro CubeSat. Celá jednotka je navržena z komerčně dostupných komponent. Návrh jednotky je proveden tak, aby umožnil její funkci ve vesmírném prostředí. Stav konfigurace FPGA je pravidelně kontrolován a v případě zjištěné chyby dochází automaticky k rekonfiguraci FPGA a návratu jednotky do výchozího stavu. Jednotka obsahuje sadu senzorů, které monitorují její stav a v případě potřeby je možné na základě jejich výstupů provést opatření z hlediska ochrany funkce jednotky. Dvě paměti MRAM umožňují uložení tovární a uživatelské konfigurace FPGA, mezi kterými dochází k automatickému přepnutí na základě korektnosti uživatelské konfigurace.
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Harris, Anthony D. "NPS CubeSat Launcher-lite sequence." Thesis, Monterey, Calif. : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Jun/09Jun%5FHarris.pdf.
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Thesis (M.S. in Space Systems Operations)--Naval Postgraduate School, June 2009.<br>Thesis Advisor(s): Newman, James H. "June 2009." Description based on title screen as viewed on July 10, 2009. Author(s) subject terms: NPSCuL, NPSCuL-Lite, P-POD, Sequencer, Launcher, Launch Vehicle, Microcontroller, Space, Satellite. Includes bibliographical references (p. 167-168). Also available in print.
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Hicks, Christina M. "NPS CubeSat Launcher program management." Thesis, Monterey, California : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Sep/09Sep%5FHicks.pdf.
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Thesis (M.S. in Space Systems Operations)--Naval Postgraduate School, September 2009.<br>Thesis Advisor(s): Newman, James H. "September 2009." Description based on title screen as viewed on November 10, 2009. Author(s) subject terms: NPSCuL, CubeSat, Launcher, P-POD, ABC, Aft Bulkhead Carrier, Centaur, ESPA, Secondary Payload, Program Management. Includes bibliographical references (p. 61-63). Also available in print.
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Zohar, Guy G. "AD-HOC REGIONAL COVERAGE CONSTELLATIONS OF CUBESATS USING SECONDARY LAUNCHES." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/927.
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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 in a single launch are explored. The deployed constellations are examined for equal separation of Cubes in a single plane and effectiveness of ground coverage of two regions. The regions examined are a large near-equatorial zone and a medium sized high latitude, high population density zone.
Results indicate that simple deployment strategies can be utilized to provide significant CubeSat dispersion to create efficient constellation geometries. The same deployment strategies can be used to develop a multitude of differently dispersed constellations. Different launch opportunities can be utilized to tailor a constellation for a specific region or mission objective. Constellations can also be augmented using multiple launch opportunities to optimize a constellation towards a specific mission or region. The tools developed to obtain these results can also be used to perform specific analysis on any region in order to optimize future constellations for other applications.
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Frances, Matas Jordi. "Internal Wireless Bus for a CubeSat." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elektronikk og telekommunikasjon, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-23088.
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NTNU (Norwegian University of Science and Technology) hosts NUTS (NTNU Test Satellite), which is mainly envisioned as an educational satellite where most tasks are performed by students while supported by university staff. As a peculiarity this CubeSat, unlike many others, is not based on the PC104 Standard. It is, instead, developed around a backplane approach, similar to a motherboard on a desktop computer. This novel approach left us without the possibility to use readily available commercial modules for CubeSats and also with the responsibility to design an ad-hoc solution for power distribution and on-Board communication. CubeSat Space Protocol on an I2C-bus was decided as the solution for the main communication bus.Although for this given satellite the payload will be an IR Camera, the main idea is to develop a reusable platform for a variety of payloads. Thus the exploration of new and novel technologies to be used in such platforms is also a goal. Specifically studying the viability of using an intra-satellite RF link is a specific area that NUTS is keen on exploring. Therefore a communication bus on radio is being developed. There are some advantages to the use of a wireless intra-satellite bus including: lower costs (both economic and in weight) and the possibility to have several transmissions in parallel. The latter could be attained by the use of virtual channels(or similar solutions) that most vendors provide on their radio kits. A proper exploitation of such features would significantly increase throughput while not requiring additional hardware.The RF link would only be the physical layer, as it is intended to still use CSP on top of it. By keeping CSP an easier portability insured to those CubeSats that already rely on CSP.COTS radio modules are being used on the proof-of-concept implementation. This should also help for an easier deployment of this communications approach on future satellites, since components are readily available. Those satellites that are equipped with both wired and wireless busses for communication, such as NUTS, could use one as a fallback solution should the other fail. Since most of the communication stack would remain untouched the transitions between wired and wireless busses should be seamless. The implementation is kept as hardware independent as possible, thus deploying it on other satellites should be relatively effortless.
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Griffith, Robert C. "Mobile Cubesat Command and Control (MC3)." Thesis, Monterey, California. Naval Postgraduate School, 2011. http://hdl.handle.net/10945/5591.
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Approved for public release; distribution is unlimited.<br>The Mobile CubeSat Command and Control (MC3) program will become the ground segment of the Colony II satellite program. The MC3 ground station contains Commercial Off-the-Shelf (COTS) hardware with Government Off-the-Shelf (GOTS) software making it an affordable option for government agencies and universities participating in the Colony II program. Further, the MC3 program provides educational opportunities to students and training to space professionals in satellite communications. This thesis analyzes the MC3 program from the program manager's point of view providing a Concept of Operations (CONOPS) of the program as well as initial analysis of MC3 ground station locations. Also included in this thesis is a future cost analysis of the MC3 program as well as lessons learned from the NPS acquisition process.
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Ziegler, Caleb Kevin. "A jam-resistant CubeSat communications architecture." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112484.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2017.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 133-140).<br>This thesis proposes a communications system that utilizes the benefits of CubeSats to provide jam-resistant communications. The growth of CubeSats within educational communities has prompted their use in industry; both industry and academia have contributed towards making CubeSats much more capable. CubeSats can now perform many advanced missions, from technology demonstrations to Earth observation missions and science missions. Meanwhile, military satellite communications (MILSATCOM) continues to rely primarily on large, highly-capable satellites. CubeSats could augment MILSATCOM by providing many low-cost space terminals with short development times as a means to create a more robust communications suite. The CubeSat communications architecture proposed in this thesis aims to support mobile users in hostile environments who need to relay information to a command center. Jam-resistant communications are achieved by performing ground-based beam-forming (GBBF) on a radio-frequency (RF) uplink and relaying the information to a ground station via a laser communications (lasercom) downlink: each CubeSat acts as an element of a sparse antenna array. With the growth of free-space lasercom in the last decade, lasercom is now a reality on CubeSat-scale platforms. Lasercom systems have lower size, weight, and power (SWaP) compared to RF systems with similar data rates, making them a good fit for CubeSat platforms. GBBF is a special case of beamforming where each element of an antenna array relays its signal to a ground station for processing, minimizing complexity on the space terminal. Beam-forming provides anti-jamming capabilites due to the spacings between elements in the array, also known as spatial diversity. This spatial diversity allows spatial filtering to occur, which modifies the array's radiation pattern to mitigate interference, add gain to the main lobe, or add multiple beams. The system is designed with the goal of minimizing cost and development time, and two ways of accomplishing this are by supporting currently fielded handheld RF transmitters and by utilizing a lasercom downlink which is being developed as part of the Nanosatellite Optical Downlink Experiment (NODE) in MIT's Space, Telecommunications, Astronomy, and Radiation Lab (STARLab). This thesis builds on previous work done on the NODE project, specifically the waveform design for NODE. NODE is a 3U CubeSat demonstrating a lasercom down-link while in low Earth Orbit (LEO). NODE uses 200mW transmit power to obtain data rates from 8 Mbps to 80 Mbps. The Optical Communications Telescope Laboratory (OCTL) at the Jet Propulsion Laboratory (JPL) and an amateur telescope will be used as optical ground stations. In order to send information to the ground station, NODE uses a waveform that provides forward error correction (FEC) and interleaving to mitigate channel effects. This thesis develops the channel coding, interleaving, modulation, and framing approach employed in the NODE waveform to provide error-free communications. A Reed-Solomon code, selected because of its performance and the existence of open-source implementations, provides error-correction capabilities. NODE uses a one-second interleaver to combat the effects of channel fading when the laser beam passes through the atmosphere. The transmitter uses pulse position modulation (PPM), an intensity modulation scheme that uses the delay of a single pulse within a symbol time to transmit information, due to the advantages in using a duty-cycled waveform with an average-power limited optical amplifier. Since the delay of the pulse conveys information for PPM, the transmitter clock must be recovered in order to properly demodulate the received waveform, and NODE uses inter-symbol guard times to encode the transmitter clock onto the waveform. Python simulations are presented showing that the channel coding, interleaving, and modulation are sufficient to obtain error-free communications with a target channel bit error rate (BER) of 1 x 10-⁴. The modulator is implemented within a field programmable gate array (FPGA), and the design, validation, and testing of the modulator are described. The feasibility of performing GBBF on RF uplinks to CubeSats in LEO, where each CubeSat acts as an element of an adaptive array, is examined. The high Doppler and large spacing between CubeSats requires the use of a space-time-frequency adaptive processor (STFAP). The STFAP consists of Doppler and delay taps, complex weights, an adaptive processor, a polyphase filter bank, and a polyphase combiner. The STFAP becomes infeasible as the Doppler and delay spread between different CubeSats increases, and analysis is used to identify scenarios where the Doppler and delay spreads seen in LEO are acceptable. Systems Tool Kit (STK) simulations are performed to analyze the Doppler and delay environment in LEO. Two CubeSat formations and multiple orientations between a user and jammer are examined to determine cases where null-forming, a special case of beamforming, is effective. A constellation is necessary to provide global coverage and maximize the effectiveness of null-forming, and two possible constellations are discussed.<br>by Caleb Kevin Ziegler.<br>S.M.
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Cordeiro, Timothy Joseph. "Dynamic instabilities imparted by CubeSat propulsion." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/105612.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2016.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 120-123).<br>As the role of CubeSats evolves to include more challenging and complex missions in addition to technology demonstrations, the demand for agility have increased. As the technology improves and gains flight heritage, CubeSats are being deployed to accomplish more difficult missions including, but not limited to, large constellations and missions beyond Low Earth Orbit (LEO). To perform missions like station keeping for constellations, and to move beyond LEO, CubeSat developers are increasingly integrating propulsion into the design of their CubeSats. In addition, more complex payloads and communication systems require more power generation, which leads to larger deployed solar arrays. Meanwhile, the limiting factor for the CubeSat remains the size and weight constraints of the containerized launch deployers. In order to meet these constraints, the solar array design has to trade stiffness and strength for size. In this work, we investigate whether designs that use a combination of propulsion and solar arrays stress the dynamics of the solar panels and the hinges that hold them in place. Our approach uses SimXpert to perform dynamic simulations on CubeSat models, both 3U and 6U, with deployable solar panels and propulsion forces. By default, SimXpert treats every part as a rigid body and stress is not calculated. By doing a modal analysis of the panels in Nastran and importing the results into SimXpert, stress on the panels can be tracked during propulsive maneuvers. We determine that Margin of Safety (MoS) for the solar panels analyzed is over 100 when combined with three different COTS propulsion units. We also show the movement induced on the panels from propulsion can cause errors in body attitude ranging from 0.04 to 90 degrees. The worst case showed a difference becoming one degree in five seconds before growing exponentially to 90 degrees in 30 seconds.<br>by Timothy Joseph Cordeiro.<br>S.M.
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Ahmed, Ozomata D. "Hybrid propulsion system for CubeSat applications." Thesis, University of Surrey, 2016. http://epubs.surrey.ac.uk/812899/.
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The CubeSats platform has become a common basis for the development and flight of very small, low cost spacecraft-particularly amongst University groups. The smallest CubeSats are just 1 litre in volume-comprising a 10.
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Anderson, Jason Lionel. "Autonomous Satellite Operations For CubeSat Satellites." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/256.
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In the world of educational satellites, student teams manually conduct operations daily, sending commands and collecting downlinked data. Educational satellites typically travel in a Low Earth Orbit allowing line of sight communication for approximately thirty minutes each day. This is manageable for student teams as the required manpower is minimal. The international Global Educational Network for Satellite Operations (GENSO), however, promises satellite contact upwards of sixteen hours per day by connecting earth stations all over the world through the Internet. This dramatic increase in satellite communication time is unreasonable for student teams to conduct manual operations and alternatives must be explored. This thesis first introduces a framework for developing different Artificial Intelligences to conduct autonomous satellite operations for CubeSat satellites. Three different implementations are then compared using Cal Poly's CP6 CubeSat and the University of Tokyo's XI-IV CubeSat to determine which method is most effective.
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Smith, Liam Colin. "Interplanetary Ridesharing: Exploring Potential CubeSat Trajectories." DigitalCommons@CalPoly, 2015. https://digitalcommons.calpoly.edu/theses/1487.
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Ever since the revolutionary CubeSat form factor took hold in the Aerospace industry, there has been a desire to send them further and further into space. This thesis introduces an optimization approach to deployment that explores new possibilities of interplanetary CubeSats. In this approach there are three categories of objective functions that are defined by the type of trajectory of a “primary” spacecraft, which carries the CubeSat deployer. These categories are flyby, orbiter, and lander. For each category the objective function starts with four design variables. These are the ΔV of the deployer broken up into three component directions and the true anomaly at the time of deployment. The method then calculates the mission specific objective to be minimized and uses Matlab®’s built in gradient-based optimizer, fmincon. The results show that in the flyby category, the CubeSat has a significantly different turning angle than the primary. The CubeSat can even flyby on the opposite side of the planet. In the orbiter case it is shown that the method works by testing it with two objective functions, the difference in inclination and the difference in eccentricity between the primary and the CubeSat. It is shown that the inclination can be changed by 0.1314° and the eccentricity can be changed by 0.0033. These values, although low in magnitude, are an order of magnitude greater than non-optimal deployment scenarios. Still, another optimization method is introduced to find out how much extra ΔV the CubeSat would need to reach a desired change. This shows that with just an extra 75 m/s of ΔV, the CubeSat can change its orbit by 5°. This could come from either a propulsion system or a modified deployer. The final category, lander, used the flight path angle when entering the atmosphere as an objective. The method shows that flight path angle can be changed by 2.6°. Overall, these examples have proven that the method can find optimal solutions to CubeSat deployment scenarios at other planets.
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Smalarz, Bradley Ryan. "CubeSat Constellation Analysis for Data Relaying." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/650.
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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 user interface, called SATCAT, was constructed in order to provide a user with the ability to control many aspects of the STK Engine externally. A function was created to use three Time Ordered Access (TOA) reports from STK to determine how long it would take for data to be relayed from a target to a ground station through a constellation of CubeSats. Three sample scenarios were created to demonstrate the use and performance analysis capabilities of SATCAT. The performance of a single CubeSat was analyzed and compared to the performance of a three CubeSat constellation and a thirty-seven CubeSat constellation. It was shown that a constellation of three CubeSats decreased the average relay time from 328 minutes to 149 minutes and a constellation of thirty-seven CubeSats further reduced the average relay time to only 3 minutes. While decreasing the average relay time, the constellation of three CubeSats also increased the number of accesses over a twenty-four hour period from 6 to 36, and the constellation of thirty-seven CubeSats allowed for 564 accesses.
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White, Michael T. "CubeSat Constellation Design for Intersatellite Linking." Scholar Commons, 2019. https://scholarcommons.usf.edu/etd/7987.
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This thesis investigates the concept of controlling a CubeSat constellation in low-Earth orbit. Low-Earth orbits are considered because the torque used for satellite control is supplied with magnetorquers, and the closer the satellite is to Earth’s magnetic field the more control gain can be supplied. Also, this is the expected orbit altitude of future CubeSat constellations to enable communications.
Controlling a CubeSat relies on attitude determination. This means being able to estimate its attitude relative to a given reference frame. To determine the attitude, we propose to use a star tracker and a Kalman filter. A star tracker scans the stars in the satellite’s view, correlates the object to a database, to return an attitude measurement. The measurement is then processed using the Kalman filter. The attitude estimate is then used as the reference input for the controller.
Once the attitude of the satellites is determined, a controller can be implemented; assuming the system is controllable and observable. These parameters are verified by adding enough actuators and sensors, respectively.
The novelty of this thesis is constructing a controller that will take three satellites and their attitude estimates and arrange them broadside to a target. For simplicity, the arrangement will be a linear formation, and the target and satellite constellation will all be near-field communication. The goal is to place the satellite constellation in an attitude for an intersatellite link to be established. This is a proposed solution to better budget power and computational constraints associated with CubeSats. In addition to adjusting the topology of the system, a communication method must be considered for the data to be distributed across the system requiring an antenna design to implement the communication method. Both issues are discussed in the thesis; however, the focus is the controller design for attitude control. The control approach is a multi-input multi-output (MIMO) sliding fuzzy controller. The focus of the analysis is attitude control for communication while maintaining the constellation in a linear formation. The results shown this controller to be a valid proof of concept.
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Le, Gaux Clyde R. III. "STARE CubeSat Communications Testing, Simulation and Analysis." Thesis, Monterey, California. Naval Postgraduate School, 2012. http://hdl.handle.net/10945/17397.
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Approved for public release; distribution is unlimited<br>The Space-based Telescope for the Actionable Refinement of Ephemeris (STARE) CubeSat will play an important role in contributing to this nations space situational awareness (SSA), perhaps one day becoming an integral part of the space surveillance network (SSN) to track orbital debris and satellites, both active and inactive. STARE is a pathfinder mission that is expected to show that CubeSat assets can improve the accuracy of space debris ephemeris data and help national assets avoid conjunction. However, STARE cannot do its job if it cannot communicate effectively with the ground architecture. Knowing the functionality of the on board radio is essential to knowing the capabilities and limitations of the spacecraft. STARE is designed to communicate with the Mobile CubeSat Command and Control (MC3) ground station at the Naval Postgraduate School for data collection and analysis. This thesis shows testing and results, analysis and simulation of the STARE radio and the MC3 ground stations.
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Develle, Michael James II. "Optimal attitude control management for a cubesat." Master's thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4752.
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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. Three-axis control in a cubesat can be achieved by combining magnetic torque coils with other devices such as thrusters, but the lifetime is limited by the fuel source onboard. To maximize the mission lifetime, a fast attitude control management algorithm that could optimally manage the usage of the magnetic and thruster torques is desirable. Therefore, a recently developed method, the B-Spline-augmented virtual motion camouflage, is presented in this defense to solve the problem. This approach provides results which are very close to those obtained through other popular nonlinear constrained optimal control methods with a significantly reduced computational time. Simulation results are presented to validate the capabilities of the method in this application.<br>ID: 030646253; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.A.E.)--University of Central Florida, 2011.; Includes bibliographical references (p. 45-49).<br>M.S.A.E.<br>Masters<br>Mechanical and Aerospace Engineering<br>Engineering and Computer Science<br>Aerospace Engineering; Space System Design and Engineering Track
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O'Brien, Tolulope E. "Space situational awareness CubeSat concept of operations." Monterey, California. Naval Postgraduate School, 2011. http://hdl.handle.net/10945/10664.
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The concept of space situational awareness (SSA) is important to preserve manned and unmanned space operations. Traditionally, ground based radar, electro-optical sensors and very limited space-based assets have been used as part of the space surveillance network (SSN) to track orbital debris, inactive and active satellites alike. With the current SSN assets aging and the need for SSA growing, it is important to explore new ways to ensure proper SSA is maintained to preserve space operations. The Space-based Telescope for the Actionable Refinement of Ephemeris (STARE) project was initiated to explore the potential for a cube satellite (CubeSat) to contribute to the current SSN, with an optical payload integrated into a 3U Colony II Bus. The bus and payload data from the CubeSat will be collected by the Naval Postgraduate School Mobile CubeSat Command and Control ground station. Telemetry data from the bus will be analyzed at NPS and the payload data at Lawrence Livermore National Laboratory. This thesis outlines the concept of operation for the STARE CubeSat and investigates the possibility of using the data generated by STARE to augment the SSN to reduce the errors associated with conjunction analysis performed at the Joint Space Operations Center.
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Chandrashekar, Shreyas. "Thermal Analysis and Control of MIST CubeSat." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-200929.
Full textAbstract:
The thermal analysis and control provides the necessary means to control the temperatureof the satellite during the harsh conditions in space. MIST CubeSat presents a challengingtask to design such a system with its various payloads and subsystems on board. Thisthesis report aims to describe the modelling and design of the thermal control systemdeveloped for MIST CubeSat in detail.Each of these payloads and subsystems have different thermal requirements that has tobe met in order to maintain thermal equilibrium. Hence in this project, all the units aregiven equal importance for the analysis to ensure the safety. A detailed thermal modelof MIST CubeSat was developed using Systema-Thermica software. With this model,three different thermal cases such as the Hot Operational case, Cold Non-Operationaland Operational cases were analysed. Furthermore, an initial dissipation profile for allthe units present in the CubeSat was created for the thermal analysis. Based on thetemperatures obtained, a thermal control system was designed to maintain the thermalbalance between the satellite and the environment. This report also gives details of theassumptions made at certain points of the analysis.The thermal control system for MIST CubeSat consists of both passive and active means.The passive means includes the use of thermal tapes on some of the payloads and subsystemson board. It was observed that the passive means were not enough to maintain thetemperatures and hence active systems such as heaters were implemented for certain units.The results indicate that not all the payloads are within the tolerable limits and hencefurther development of the thermal control system is needed. Lastly the results includethe overall design changes made in the model and a conclusion along with a possibility offuture work has been discussed.<br>Termisk analys och kontroll förser de nödvändiga metoderna för att kontrollera temperaturenpå satelliten under de extrema omständigheterna i rymden. MIST CubeSat presenteraren utmanande uppgift i att designa ett sådant system med dess olika nyttolasteroch delsystem ombord. Denna rapport syftar till att beskriva i detaljerad modelleringoch designen av den termiska kontrollen som har utvecklats för MIST CubeSat.Var och en av dessa nyttolaster och delsystem har olika termiska krav som måste uppfyllasför att upprätthålla termisk jämvikt. Därför i detta projekt, alla enheter ges likastor betydelse för analysen för att kunna garantera dess termiska jämvikt. En detaljeradtermisk modell av MIST CubeSat har utvecklats med hjälp av Systema-THERMICA programvara.Med denna modell, tre olika termiska fall har analyserats; Varmt operativtfall, Kallt icke-operativt samt kallt operativa fall. Experimentens och del systemens dissipationsprofilkommer ha betydelse för temperaturen av enheten och en förenklad profil förde olika enheterna har implementerats i denna termiska modell. Baserat på de temperaturersom erhölls, ett termiskt styrsystem var konstruerad för att bibehålla den termiskajämvikten mellan satelliten och omgivning. Denna rapport presenterar också detaljer omde antaganden som gjorts vid vissa moment i analysen. Det termiska styrsystem för MIST CubeSat består av både passiva och aktiva metoder.Den passiva metoden inkluderar användning av termisk tejp på en del av nyttolasterna ochdelsystemen ombord. Det kunde konstateras att den passiva metoden inte var tillräckligtför att bibehålla temperaturerna och därmed aktiva system, såsom värmare användas förvissa enheter. Resultaten tyder på att inte alla nyttolaster ligger inom acceptabla gränseroch därmed ytterligare utveckling av den termiska styrsystem behövs göras. Slutligen,resultaten inkluderar de övergripande konstruktionsändringar som gjorts i modellen samten slutsats om möjlighet till framtida arbete har diskuterats.
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Nzeugaing, Gutembert Nganpet. "Image compression system for a 3u cubesat." Thesis, Cape Peninsula University of Technology, 2013. http://hdl.handle.net/20.500.11838/1085.
Full textAbstract:
Thesis submitted in partial fulfilment of the requirements for the degree of
Master of Technology: Electrical Engineering
in the Faculty of Engineering
at the Cape Peninsula University of Technology
2013<br>Earth observation satellites utilise sensors or cameras to capture data or images that are relayed to the ground station(s). The ZACUBE-02 CubeSat currently in development at the French South African Institute of Technology (F’SATI) contains a high resolution 5 megapixel on-board camera. The purpose of the camera is to capture images of Earth and relay them to the ground station once communication is established. The captured images, which can amount to a large volume of data, have to be stored on-board as the CubeSat awaits the next cycle of transmission to the ground station. This mode of operation introduces a number of problems, as the CubeSat has limited storage and memory capacity and is not able to store large amounts of data. This, together with the limitation of the downlink capacity, has set the need for the design and development of an image compression system suitable for the CubeSat environment.
Image compression focuses on reducing the size of images to be stored as well as reducing the size of the images to be transmitted to the ground station. The purpose of the study is to propose a compression system to be implemented on ZACUBE-02. An intensive study of current, proposed and implemented compression methods, algorithms and techniques as well as the CubeSat specification, served as input for defining the requirements for such a system.
The proposed design is a combination of image segmentation, image linearization and image entropy coding (run-length coding). This combination technique is implemented in order to achieve lossless image compression. For the proposed design, a compression ratio of 10:1 was obtained without negatively affecting image quality.The on-board storage memory constraints, the power constraints and the bandwidth constraints are met with the implementation of the proposed design, resulting in the downlink transmission time being minimised.
Within the study a number of objectives were met in order to design, implement and test the compression system. These included a detailed study of image compression techniques; a look into techniques for improving the compression ratio; and a study of industrial hardware components suitable for the space environment.
Keywords: CubeSat, hardware, compression, satellite image compression, Gumstix Overo Water, ZACUBE-02.
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Bylund, Oscar. "Attitude Determination and Control of a Cubesat." Thesis, KTH, Rymdteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-231376.
Full textAbstract:
This report describes the feasibility of attitude determination and control of the student satellite MIST. It investigates the stability and controllability of the satellite system, it covers attitude determination based on magnetometer and sun sensor measurements available and finally compares two controllers and the resulting pointing accuracy of the satellite. The study shows that the pointing requirements can be met under nominal circumstances.<br>I denna rapport utreds hur noggrannt en studentsatellits attityd kan uppskattas och kontrolleras. Sensorerna och aktuatorerna består av en magnetometer, tre magnetiska spolar och sex solsensorer. Mätningarna filtreras och används i två olika regleralgoritmer, följt av en jämförelse mellan resultaten av de båda metoderna. Rapporten visar att satellitens noggrannhetskrav på attityden kan uppfyllas under normala förhållanden.
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Leffke, Zachary James. "Distributed Ground Station Network for CubeSat Communications." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/25151.
Full textAbstract:
In the last decade the world has seen a steadily increasing number of Cube Satellites deployed to Low Earth Orbit. Traditionally, these cubesats rely on Amateur Radio communications technology that are proven to work from space. However, as data volumes increase, the existing Amateur Radio protocols, combined with the restrictions of use for the Amateur Radio Spectrum, as well as the trend to build one control station per cubesat, result in a bottle neck effect whereby existing communications methods are no longer sufficient to support the increasing data volumes of the spacecraft.
This Masters Thesis work explores the concept of deploying a network of distributed ground station receiver nodes for the purposes of increasing access time to the spacecraft, and thereby increasing the potential amount of data that can be transferred from orbit to the ground. The current trends in cubesat communications will be analyzed and an argument will be made in favor of transitioning to more modern digital communications approaches for on orbit missions. Finally, a candidate ground station receiver node design is presented a possible design that could be used to deploy such a network.<br>Master of Science
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Crook, Matthew R. "NPS CubeSat launcher design, process and requirements." Thesis, Monterey, Calif. : Naval Postgraduate School, 2009. http://handle.dtic.mil/100.2/ADA501503.
Full textAbstract:
Thesis (M.S. in Space Systems Operations)--Naval Postgraduate School, June 2009.<br>Thesis Advisor(s): Newman, James H. "June 2009." Description based on title screen as viewed on July 13, 2009. DTIC Identifiers: NPSCUL (NPS CUBESAT Launcher), ESPA (EELV Secondary Payload Adapter), P-POD (Poly Picosatellite Orbital Deployer), nanosatellite standards, CRADA (Cooperative Research and Development Agreement), EELV (Evolved Expendable Launch Vehicle), FDM (Fused Deposition Modeling), geosynchronous orbits, low earth orbits, rapid prototyping. Author(s) subject terms: CubeSat, NPSCuL, ESPA, EELV, Satellite, Space, Launcher, Launch. Includes bibliographical references (p. 77-78). Also available in print.
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Karagiannakis, Philippos. "Communications for CubeSat networks and fractionalised spacecraft." Thesis, University of Strathclyde, 2017. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=28413.
Full textAbstract:
The use of low-cost CubeSats in the context of satellite formation flying appears favourable due to their small size, relatively low launch cost, short development cycle and utilisation of commercial off the shelf components. However, the task of managing complex formations using a large number of satellites in Earth orbit is not a trivial one, and is further exacerbated by low-power and processing constraints in CubeSats. With this in mind, a Field Programmable Gate Array (FPGA) based system has been developed to provide next generation on-board computing capability. The features and functionality provided by this on-board computer, as well as the steps taken to ensure reliability, including design processes and mitigation techniques are presented in this work and compared to state of the art technology. Coupling reliable formation flying capabilities with the possibility of producing complex patterns using spacecraft will enable the potential of grouping a number of antenna elements into a cooperative structure. The key point in the exploitation of formation flying techniques for the deployment of an antenna array is that the performance of a homogeneous pattern of array elements can be matched or surpassed by fractal geometries. This thesis analyses the Purina fractal array when utilised for beamforming. A new metric termed power concentration is introduced, which assesses the power dissipated within a cone aligned with the array's look direction, i.e. an assessment how much of the radiated power will reach a specific foot print. Using this metric the performance for beamformers of varying complexity can be compared, independent of the number of sensor elements used to form the array and across a range of frequencies. Furthermore the robustness of the array with respect to element displacement and failure is investigated. The fractionated nature of such a satellite network and the low-power nature of the nodes motivates distributed processing when using such an array as a beamformer. By mirroring the fractal structure in the processing architecture, the proposed idea demonstrates that benefits such as strictly limited local processing capability independent of the array’s dimension and local calibration can be bought at the expense of a slightly increased overall cost.
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Crews, Angela B. (Angela Beth). "Calibration and validation for CubeSat Microwave Radiometers." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122368.
Full textAbstract:
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Thesis: Ph. D., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2019<br>Cataloged from student-submitted PDF version of thesis.<br>Includes bibliographical references (pages 187-194).<br>Miniaturized microwave radiometers deployed on nanosatellites in Low Earth Orbit (LEO) are now demonstrating the ability to provide science-quality weather measurements. For instance, the Micro-sized Microwave Atmospheric Satellite-2A (MicroMAS-2A) is a 3U CubeSat launched in January 2018 that provided the first CubeSat microwave atmospheric sounder data from orbit. The goal of having cost-effective miniature instruments distributed in LEO is to field constellations and improve temporal and geospatial coverage. The Time-Resolved Observations of Precipitations structure and storm Intensity with a Constellation of Smallsats (TROPICS) is a constellation of six 3U CubeSats, based on MicroMAS-2A, scheduled to no earlier than 2020. Each CubeSat hosts a scanning 12-channel passive microwave radiometer in W-band, F-band, and G-band.<br>TROPICS will provide a temporal resolution of less than 60 minutes and will provide high value investigations of inner-core conditions for tropical cyclones [1]. Calibration for CubeSats presents new challenges as standard blackbody targets are difficult to effectively shroud on a CubeSat platform. Instead, internal noise diodes are used for calibration on CubeSats. The Global Precipitation Measurement (GPM) Microwave Imager (GMI) instrument has shown noise diodes to be stable on orbit [2], but the noise diodes have not been tested on-orbit at TROPICS frequencies. In order to provide state of the art calibration for CubeSats, methods must be developed to track and correct noise diode drift. We quantitatively determine the radiometric accuracy of MicroMAS-2A and compare it to state of the art instruments to provide an assessment of CubeSat performance.<br>Radiometric accuracy is determined by using the Community Radiative Transfer Model (CRTM) and the Rosenkranz Line-by-Line (LBL) Radiative Transfer Model (RTM) with inputs from GPS radio occultation (GPSRO), radiosondes, and Numerical Weather Prediction (NWP) models in order calculate simulated brightness temperatures that are used as the ground truth. We perform on-orbit calibration corrections using data matchups between MicroMAS-2A and the MicroWave Humidity Sounder (MWHS)-2, which is a microwave radiometer on the operational Chinese weather satellite FengYun (FY)-3C with similar bands. Brightness temperature histograms are analyzed to calculate an initial calibration correction; we develop a Markov Chain-Monte Carlo (MCMC) technique that calculates calibration correction results within 1.2% of the brightness temperature histograms method.<br>The double difference technique is then used to compare the corrected MicroMAS-2A data to the state-of-the-art microwave radiometer Advanced Technology Microwave Sounder (ATMS) on Suomi-NPP. Double difference results computed using both CRTM and LBL as well as atmospheric inputs from both radiosondes and NWP models indicate MicroMAS-2A accuracies ranging from approximately 0.05 K to 2.73 K, depending on the channel. The upper atmospheric temperature sounding channels for which modeling and surface contamination errors are least significant yield intercalibration accuracies better than 1.0 K. We also develop a novel method of calibration for CubeSat constellations such as TROPICS by incorporating solar and lunar periodic intrusions as an additional source of information to counter noise diode drift.<br>These lunar intrusions also occur for existing satellites hosting microwave radiometers in sun-synchronous polar orbits, but are much more infrequent than for the TROPICS constellation's scanning payload. Lunar intrusions are typically treated as an observational and calibration limiting constraint. We develop a solar/lunar calibration algorithm and test it using ATMS lunar intrusion data. The mean bias and standard deviation between the algorithm and actual ATMS data falls within the expected ATMS error budget of 0.6 K to 3.9 K, showing that the algorithm is working correctly and can be applied to TROPICS. We assess the daily variation in error that we can expect from instrument noise and source error, and find that lunar intrusions should be analyzed weekly while solar intrusions should be analyzed daily to track 1 K of noise diode drift. In addition, we develop an architecture for validation matchups with TROPICS.<br>We determine frequencies of single difference matchups, double difference matchups using both intra- and inter- Simultaneous Nadir Observations (SNO), and solar and lunar intrusions. Matchup sensitivity to orbital parameters is studied and we find that changes in true anomaly and Right Ascension of Ascending Node (RAAN) do not decrease the number of SNO matchups that are within our filter criteria of 60 minutes.<br>by Angela B. Crews.<br>Ph. D.<br>Ph.D. Massachusetts Institute of Technology, Department of Aeronautics and Astronautics
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Burt, Robert. "Distributed Electrical Power System in Cubesat Applications." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/1052.
Full textAbstract:
The single bus voltage distributed architecture is the mainstay architecture for small satellite spacecraft. Even large satellites follow this architecture. While they may have more than one voltage that is distributed, such as a high voltage bus and a low voltage bus, within a subsystem, there is usually one bus voltage. Each subsystem component is responsible for further regulation or point-of-load regulation. The Nano-satellite class, and more particularly the cubesat, have broken away from this norm and overwhelmingly implement a centralized architecture. With the advances of small, highly efficient monolithic dc-dc converters, this thesis researches the possibilities of implementing the distributed architecture at the cubesat scale. The Goal is to create a very efficient electrical power system design that has a high degree of utility, allowing it to be used for multiple missions, without having to redesign the system every time.
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Manyak, Greg D. "Fault Tolerant and Flexible CubeSat Software Architecture." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/550.
Full textAbstract:
The CubeSat pico-satellite is gaining popularity in both the educational and aerospace industries. Due to a lack of experience and constrained hardware capabilities, most of the university missions have been educational in nature. Cal Poly's project, PolySat, has gained significant experience from the launch of five CubeSats and has designed an entirely new hardware platform based on the knowledge gained from these missions. This hardware is a significant upgrade from what the previous missions used and has greatly increased the capabilities of the software, including supporting the use of the open source operating system Linux.
Leveraging the previous PolySat experience, a new design approach has been followed for the development of a fault tolerant and flexible software architecture. As a result, a set of processes and custom libraries that run within Linux have been designed and implemented. Furthermore, an emphasis has been placed on fault tolerance with two features: a software watchdog and digital command signing capability. Lastly, a survey of related CubeSat projects and software fault tolerance papers has been conducted to determine that this new system is sufficient to meet the desired goals.
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MOZZILLO, RAFFAELE. "Technologies and methodologies for CubeSat performances improvement." Doctoral thesis, Politecnico di Torino, 2016. http://hdl.handle.net/11583/2643293.
Full textAbstract:
The importance of small satellites, and in particular of nano-satellites (e.g. CubeSats) has increased during last years thanks to major improvements in the field of electrical and mechanical miniaturisation. Another important factor is represented by the interest of national and international space agencies, which has led to the creation of many scientific small satellites programmes, beyond several educational ones. “Small satellites” term shall not be considered referring only to mass, but it describes also a new approach to building, operating, and managing risk for satellite systems; in fact, CubeSat standard (whose reference design was proposed in 1999, and first launch occurred in 2003) is becoming a concrete realisation of a new way of thinking space systems, which is changing the way to access the space. Commercial components, rapid scheduling, risk tolerance and lean testing are just some of features behind the success and spread of CubeSats among universities, space agencies, research and scientific centres, and private companies.
Current CubeSat and small satellite missions are mostly developed for Low Earth Orbit (LEO) application, and the number of scientific goals/tasks that they can perform is still limited. CubeSats are nowadays a mature technology to perform Earth observation with low-to-medium performance, and they are a valid educational tool to train young engineers and students in the process of conceiving, implementing and operating a space mission. However, it is possible to say we are entering a new CubeSat Era, in which CubeSats will be called to carry out real missions of the future. Within the new framework, they may represent new test-beds for future bigger missions or allow independent and unprecedented new applications.
This research aims at contributing to advance the state of the art in CubeSat missions design and implementation by enhancing some technologies that will support those missions and by defining some innovative approaches for CubeSat development. This main objective has been addressed and pursued from two different points of view:
-design perspective, to contribute at improving one specific technology in one technical domain of interest at sub-system level. A subsystem, specifically the Attitude Determination and Control Subsystem (ADCS), has been chosen and the attitude determination process is the function that has been specifically analysed
-development perspective, to contribute at improving the development process of a CubeSat mission. This activity has been carried out at system-level, and addresses specifically the Assembly, Integration and Test/Verification (AIT/V) process of a CubeSat for which a new approach has been proposed based on lessons learned from past missions and innovative simulation methodologies and tools.
The problem definition for this thesis has been expressed with the following questions: “How and to what extent can the CubeSat platform support future space missions for science purposes, technology demonstration, and service applications?”, and “What features of CubeSat platforms and their missions shall be improved to meet the emerging needs and requirements?”. To answer these questions, the whole CubeSat life-cycle has been considered, analysed and eventually adapted to the rising needs. Both design aspects and development processes have been addressed, which might help improving overall CubeSat quality, extend CubeSat applications range, and finally increase mission success. The major results are represented by improvements attainable at different phases of the CubeSat life-cycle, such as design, development and verification phase, and at different levels (i.e. subsystem level and system level), through the use of In-the-Loop (IL) simulator and leveraging lessons learned and heritage from previous missions. The methodology adopted is the Model Based System Engineering (MBSE), which provides a wonderful support to solve complex problems against reduced budgets, fewer resources (in terms of personnel and money) and shorter schedules. The first part of the work has been aimed at the investigation of the CubeSat standard and its diffusion, in order to identify actions to improve performances in
view of next commercial and scientific missions. Furthermore, a detailed analysis of state-of-the-art and on-the-horizon technologies has been carried out, with a major focus on ADCS, COMmunication subSYStem (COMSYS), Electrical Power Subsystem (EPS) and propulsion subsystem.
For what concerns the subsystem level, the ADCS has been selected as case study, with a direct application on e-st@r-II CubeSat. Determination algorithms have been investigated, both static and recursive ones, and a specific recursive algorithm have been designed, developed and integrated on-board. The algorithm works in the special condition of under-observability: a single vector observation is available, which is the Earth Magnetic Field (EMF) vector. The algorithm is part of the payload of e-st@r-II CubeSat, which was selected by ESA Education Office to participate to Fly Your Satellite! (FYS!) initiative and whose launch is scheduled on 22nd April 2016 on board Soyuz ST-A VS14 from Centre Spatial Guyanais (CSG) in French Guyana. The on-orbit testing will provide additional data to validate the algorithm.
In addition to this activity, the adoption of Artificial Neural Network (ANN) technology on-board CubeSats has been investigated. The field of application of ANNs is again the ADCS: they have been designed to act as state estimator and fault detector. Several types of ANNs have been studied, in order to identify the ones with the best performances. In this application, pattern recognition neural networks and Many ADAptive LInear NEuron (MADALINE) networks have been implemented to detect and identify a fault of a gyro and to estimate angular velocities and attitude of the satellite even when a fault occurs.
For what concerns the system level, the goal of performances improvement has been pursued working not only on the design phase, but also improving the other phases, such as development, manufacturing, assembly, integration, verification and operations phases. Key aspects have been identified regarding the verification campaign for CubeSats: reference standards can not be adopted integrally, but there is a need for tailoring, creating a set of lean tests, and the use of IL simulators, in all of their forms (Algorithm-In-the-Loop (AIL), Software-In-the-Loop (SIL), Controller-In-the-Loop (CIL) and Hardware-In-the-Loop (HIL)), is fundamental, especially for verifications that could be very demanding for the flight hardware and/or very expensive. These aspects have been discussed, with reference to e-st@r-II CubeSat
functional and environmental test campaigns within the participation at FYS! programme of ESA Education Office. Finally, an additional possible way to increase the rate of success has been found into start thinking as a “manufacturing company” (i.e. in terms of mass production), and to evaluate previous missions, gathering lessons learned, extracting possible failures and drawbacks, and deducing possible improvements for future projects, at all phases of the product life-cycle. As example of this methodology, the improvements achieved on e-st@r-II CubeSat thanks to e-st@r-I CubeSat have been presented, together with the lessons learned of the environmental test campaign of e-st@r-II CubeSat performed at ESA-ESTEC, which will have an impact on next projects of the Team (e.g. 3-STAR CubeSat).
In conclusion, it has been proven that the proposed technologies and methodologies methods are effective to increase the CubeSats mission success and their performances, investigating some direct applications. Moreover, in view of future missions of CubeSats, some recommendations have been formulated, and they may be useful both for educational programs and scientific/commercial ones.
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Lascialanda, Laura. "Progetto preliminare ed analisi strutturale di un Cubesat." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/9669/.
Full textAbstract:
Lo scopo di questa tesi è progettare e analizzare la struttura più efficiente ed adeguata di un CubeSat 1U, realizzando un modello al calcolatore che sia il più possibile aderente al modello reale.
Ciò viene fatto utilizzando un software dedicato alle simulazioni avanzate, Ansys Workbench con il quale è possibile svolgere analisi modali sulla struttura realizzata. Per validare il modello numerico occorre confrontare i risultati ottenuti al calcolatore con quelli conseguiti sperimentalmente nell'ambito della tesi del mio collega Riccardo Fabbri; una volta fatto ciò si manipola il modello numerico finché i risultati non si matchano, entro un certo margine di errore.
Un modello numerico del genere è fondamentale per le fasi iniziali di qualsiasi progetto sperimentale volto alla costruzione di una struttura, infatti consente di svolgere tutta una serie di test e simulazioni di carichi e vincoli che nella realtà non si possono eseguire per via di numerosi fattori, come ad esempio la mancanza della strumentazione adeguata.
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Rossi, Matteo. "Studio ed analisi termica di un Cubesat 1U." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2018.
Find full textAbstract:
Vengono mostrati i fattori principali che influenzano la variazione di temperatura in ambiente spaziale.
Sono studiati ed analizzati, tramite il software per l’analisi termica di Ansys, i flussi termici semplificati per la missione LEO (Low Earth Orbit) del progetto Cubesat. In particolare è esposto l’utilizzo di un software commerciale Ansys e di un software di calcolo Matlab.
Si è partiti dall’analisi di un modello semplificato ad un unico nodo di un nanosatellite di tipo Cubesat, sviluppando un programma adeguato all’analisi della variazione di temperatura in Matlab. In seguito, si è ripetuto il procedimento in Ansys, andando poi a confrontare i dati ottenuti dai due modelli. Verificata la correttezza dei metodi utilizzati, si è impostato in Ansys un modello leggermente più complesso al fine di illustrare la differenza dei risultati acquisiti rispetto al modello di partenza.
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Bath, Avtar Singh. "Progettazione e analisi di strutture per Cubesat 2U." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18160/.
Full textAbstract:
Attività di progettazione, svolta su Solidworks, di due strutture per Cubesat 2U, tenendo conto di normative e restrizioni imposte da standard internazionali. Una volta finalizzate le due strutture per Cubesat, queste sono state analizzate su Ansys: sono state svolte analisi statiche, analisi a bassa frequenza e analisi random. Successivamente sono stati trovati i margini di sicurezza per capire l'affidabilità delle strutture stesse. Tenedo conto di tali margini e di altre caratteristiche delle rispettive strutture, è stato fatto un confronto tra le due e sono stati riportati vantaggi e svantaggi emergenti.
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Dalle, Fabbriche Simone. "Progetto preliminare di un Cubesat per osservazione terrestre." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19093/.
Full textAbstract:
L’obiettivo del seguente elaborato di tesi è la progettazione preliminare di un nano satellite per osservazione terrestre.
A seguito di una definizione di payload e orbita sono stati svolti i dimensionamenti di massima di alcuni dei principali sottosistemi presenti in un CubeSat.
In particolare sono stati impostati il power budget e il link budget, per definire indicativamente i requisiti dei vari componenti.
In conclusione è stato prodotto un disegno CAD del satellite per valutarne le dimensioni disponibili al payload e il centro di massa.
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Matteoni, Paolo. "Progetto del sistema di potenza per applicazioni CubeSat." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19042/.
Full textAbstract:
L’elaborato di tesi qui sviluppato presenta come oggetto il dimensionamento e la progettazione di un sottosistema di potenza per una piattaforma CubeSat, il cui sviluppo è stato recentemente avviato dall’Università di Bologna.
Il mio studio ha origine nel Laboratorio di Microsatelliti e Microsistemi Spaziali, per essere poi continuato e concluso nel Laboratorio di Satelliti presso New Production Concept S.r.l. – Space Mind a Imola.
Il sottosistema di potenza, soprattutto nelle piattaforme CubeSat, è delicato in quanto non solo produce e distribuisce la corrente elettrica a tutti i carichi presenti a bordo ma è anche lo strumento che ne permette il controllo. Eventuali failure di tale sottosistema mettono a rischio il successo dell’intera missione.
Complessivamente la tesi propone due filoni concettuali affiancati: nozioni teoriche, derivanti da studi pregressi o ricerche ad hoc, ed elementi di natura pratica, acquisiti durante l’attività di tirocinio curriculare.
Questo elaborato approfondisce ed amplia l’attività di ricerca e sviluppo intrapresa da alcuni miei colleghi negli anni passati ed in particolare conclude il dimensionamento dell’EPS, ne caratterizza il funzionamento nelle varie fasi operative e ne propone una possibile architettura.
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De, Luca Stefano. "Studio orbitale di missione CubeSat con applicativo GMAT." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2020.
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La missione per cui questo elaborato è stato redatto è relativa allo studio orbitale di un satellite CubeSat con lo scopo di garantire una navigazione nello spazio autonoma con l’aiuto dei satelliti GPS. E' stata studiata, in particolare, la natura di un nanosatellite, sempre più utilizzato ai giorni nostri per missioni di lancio nello spazio. Si è fatto uso di software quali GMAT e Matlab che hanno permesso di studiare i dati dei sottosistemi di telecomunicazione e di controllo termico utili ai fini della missione.
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De, Simei Mattia. "Analisi meccanica di una piattaforma nanosatellitare Cubesat 12U." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/20776/.
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Il contenuto della tesi è un'analisi meccanica di una piattaforma nanosatellitare Cubesat 12U; si sono analizzati i requisiti dimensionali e di massa di un Cubesat, inclusi i vari progetti e modelli relativi al 12U; si sono studiati i carichi nella fase di lancio e diversi lanciatori. La parte finale è stata dedicata all'analisi FEM su Catia del modello Cubesat 12U semplificato, partendo dalla mesh, dalla connessione delle parti, dall'introduzione di masse per simulare i payload e i vincoli sulla struttura. L'ambiente di analisi dedicata ai carichi statici è l'analisi statica mentre l'analisi dedicata alla frequenza è l'analisi modale.
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Lee, Zachary Thomas. "CubeSat constellation implementation and management using differential drag." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112471.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2017.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 107-117).<br>Space missions often require the use of several satellites working in coordination with each other. Industry examples include Planet, which is working to develop a constellation of over 100 Cube Satellites (CubeSats) to obtain global imagery data daily, and Astro Digital, which seeks to implement a constellation of multispectral imaging satellites to image the entire Earth every three to four days [1, 2]. CubeSat constellations are also being considered for applications such as secure laser communication relays and for weather sensing with short revisit times [3, 4]. Such missions require several CubeSats with regular spacing within an orbital plane to achieve their objectives. However, an appropriately arranged constellation can be particularly difficult to implement for CubeSats. Cold gas propulsion systems with the ability to provide tens of meters per second of delta-V (for a 3U CubeSat) exist and can be used for constellation management on timescales of weeks [5, 6, 7, 8, 9]. Monopropellant systems also currently exist for CubeSats, but, like cold gas systems, they can require significant power, mass, volume, and thermal management resources, and they also carry more risk [9, 10]. Launch services providers often limit acceptance of pressurized vessels, which can limit launch opportunities for CubeSats with cold gas or monopropellant propulsion systems. Although electric propulsion systems can provide up to 100 m/s delta-V for a 3U CubeSat, they also have mass, volume, cost, and power impacts, and they typically require timescales on the order of weeks to months to cause significant changes [6, 11, 9]. In low Earth orbit, there is sufficient drag to perturb satellite orbits. Though it varies widely based on conditions, at 500 kilometer (km) altitude, the acceleration due to drag on a 3U CubeSat can be around 15 [mu]m/s² per unit area [12]. Over time, this is enough acceleration to change a satellite's orbit. By controlling the attitude of a satellite, the profile area can be changed. By manipulating the profile area, the drag force can be changed, and satellites can be moved relative to each other within an orbital plane. Using differential drag at 550 km altitude, a 3U CubeSat can.move its true anomaly 180 degrees relative to another in the same orbital plane in about 100 days. Previous work with differential drag for constellation management has focused on linearized control schemes for formation flight. However, the linearized equations used for close-proximity flight are not valid for maximum-separation missions [13, 14, 15]. While some work does exist on maximum-separation missions, conditions are simplified or details on the estimation and control scheme are omitted or inadequate [8, 16, 17, 18, 19]. This work uses an unscented Kalman filter to estimate mean orbital elements and a novel control scheme to first offset and then match relative mean semi-major axes. The separation of mean semi-major axes creates different mean motions such that allow for the relative mean anomalies to be controlled. Simulation results demonstrate that differential drag can be used to control and maintain satellites within 0.5 degrees of the desired mean anomaly relative to other satellites. For two satellites in the same orbital plane at 500 km altitude seeking to maximize separation, 0.5 degrees corresponds to an angle that can be traversed in under 10 seconds. For Earth observation mission, this has a negligible effect on revisit times and can be considered an acceptable result.<br>by Zachary Thomas Lee.<br>S.M.
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Van, de Loo Mark David. "CubeSat attitude control using micronewton electrospray thruster actuation." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/90806.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2014.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 215-217).<br>Micronewton electrospray thrusters are a promising new actuator for CubeSat attitude control. Electrospray thrusters have advantages over current state of the art CubeSat attitude actuators in mass, volume, and their ability to produce translational acceleration in addition to control moments. An attitude determination and control system was designed for a 1U CubeSat assuming commercial-off-the-shelf attitude determination hardware components and six electrospray thrusters developed by the MIT Space Propulsion Laboratory. A high fidelity spacecraft dynamics simulation was constructed for analysis of the performance of the ADCS system. Attitude determination was tested with an engineering model of a 1U CubeSat, and the entire ADCS system was tested in simulation. Results of these preliminary tests show the use of electrospray thrusters as attitude actuators to be feasible, although significant work remains to complete a flight-ready ADCS system.<br>by Mark David Van de Loo.<br>S.M.
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Peters, Eric David. "Dynamic instabilities imparted by CubeSat deployable solar panels." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/93800.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2014.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 85-87).<br>In this work, multibody dynamics simulation was used to investigate the effects of solar panel deployment on CubeSat attitude dynamics. Nominal and partial/asymmetric deployments were simulated for four different solar panel assemblies. Trend lines were obtained for the evolution of the angular velocities and accelerations of the CubeSat about its center of mass for the duration of the deployment. The partial deployment simulations shed insight into the motions that an attitude control system may need to mitigate in the event of a deployment anomaly.<br>by Eric David Peters.<br>S.M.
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Bakam, Nguenouho Odette Sandrine. "Ceramic coaxial resonator filter in a CubeSat system." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2639.
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Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2017.<br>RF and microwave filters can be implemented using ceramic coaxial resonators. This technology has been widely employed in nanosatellite communications systems recently, owing to its large quality factor (Q), permitting them to have low loss and narrow bandwidth. Features such as high selectivity, high power handling, excellent rejection, and low passband insertion loss are just a few of the key performance areas offered by ceramic coaxial resonators. This feature makes them suitable for use in bandpass filters.
Applications with demanding specifications requiring low volume and mass make use of this technology. Fulfilling the required performance goals can be challenging, given the size and weight restriction. Difficulties such as finding the correct length of resonators and the coupling capacitors’ structure to meet the size restriction, limit the type of ceramic coaxial resonators to use.
This thesis presents the design of a bandpass filter using ceramic coaxial resonators, which provides evidence of the concept for F’SATI’s future needs. This design will be used in an imminent space mission and the intention is to mount the bandpass filter in the receiver communications system. An intensive investigation was conducted into the use of filters for nanosatellite communication systems. The Chebyshev LC ladder low pass prototype was used to derive the conventional bandpass filter. Thereafter, the coupled resonator bandpass filter was derived using the conventional bandpass filter topology combined with the admittance inverter. Following this, using the ceramic coaxial resonators datasheet and information provided by the manufacturers, the coupled resonator bandpass filter was converted into a 3D model for further simulations, using CST Microwave Studio®. The ceramic coaxial resonator filter fabricated using Rogers’s material provided satisfactory results at its operating frequency between 2.2 GHz and 2.3 GHz. A radiation level test was performed on the filter to justify the use of the metallic enclosure. The test presented a low level of radiation measured at the filter operating frequency (2.25 GHz). The filter was also subjected to temperature cycling.<br>French–South African Institute of Technology (F’SATI)
National Research Foundation (NRF)
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Singh, Serbinder. "A Data-Driven Approach to Cubesat Health Monitoring." DigitalCommons@CalPoly, 2017. https://digitalcommons.calpoly.edu/theses/1782.
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Spacecraft health monitoring is essential to ensure that a spacecraft is operating properly and has no anomalies that could jeopardize its mission. Many of the current methods of monitoring system health are difficult to use as the complexity of spacecraft increase, and are in many cases impractical on CubeSat satellites which have strict size and resource limitations. To overcome these problems, new data-driven techniques such as Inductive Monitoring System (IMS), use data mining and machine learning on archived system telemetry to create models that characterize nominal system behavior. The models that IMS creates are in the form of clusters that capture the relationship between a set of sensors in time series data. Each of these clusters define a nominal operating state of the satellite and the range of sensor values that represent it. These characterizations can then be autonomously compared against real-time telemetry on-board the spacecraft to determine if the spacecraft is operating nominally.
This thesis presents an adaption of IMS to create a spacecraft health monitoring system for CubeSat missions developed by the PolySat lab. This system is integrated into PolySat's flight software and provides real time health monitoring of the spacecraft during its mission. Any anomalies detected are reported and further analysis can be done to determine the cause. The system can also be used for the analysis of archived events. The IMS algorithms used by the system were validated, and ground testing was done to determine the performance, reliability, and accuracy of the system. The system was successful in the detection and identification of known anomalies in archived flight telemetry from the IPEX mission. In addition, real-time monitoring performed on the satellite yielded great results that give us confidence in the use of this system in all future missions.
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Williams, Jon A. "Enabling Validation of a CubeSat Compatible Wind Sensor." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/78711.
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The Ram Energy Distribution Detector (REDD) is a new CubeSat-compatible space science instrument that measures neutral wind characteristics in the upper atmosphere. Neutral gas interactions with plasma in the ionosphere/thermosphere are responsible for spacecraft drag, radio frequency disturbances such as scintillation, and other geophysical phenomena. REDD is designed to collect in-situ measurements within this region of the atmosphere where in-flight data collection using spacecraft has proven particularly challenging due to both the atmospheric density and the dominating presence of highly reactive atomic oxygen (AO). NASA Marshall Space Flight Center has a unique AO Facility (AOF) capable of simulating the conditions the sensor will encounter on orbit by creating a supersonic neutral beam of AO. Collimating the beam requires an intense magnetic field that creates significant interference for sensitive electronic devices. REDD is undergoing the final stages of validation testing in the AOF. In this presentation, we describe the LabVIEW-automated system design, the measured geometry and magnitude of the field and the specially designed mount and passive shielding that are utilized to mitigate the effects of the magnetic interference.<br>Master of Science
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Walker, Alex R. "Fuzzy Attitude Control of a Magnetically Actuated CubeSat." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1384333499.
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Zhou, Jiewei. "Attitude Determination and Control of the CubeSat MIST." Thesis, KTH, Farkost och flyg, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-203284.
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The ADCS concept in MIST reects the limitations of the CubeSat in terms of space, power and onboard computer computational capability. The control is constrained to the use of only magnetic torquers and the determination to magnetometers and Sun sensors in spite of the the under-actuation and underdetermination during eclipses. Usually small satellites with a similar ADCS and demanding requirements fail, therefore MIST would be a design reference for this kind of concept in the case it succeeds. The objectives of this thesis work are the feasibility assessment of the concept to meet the nominal requirements in MIST and the consideration of alternatives. Firstly, the importance of gravitational stabilization and di erent congurations for the inertial properties are analyzed based on the linear stability regions for nadir pointing spacecraft. Besides, extended stability regions are derived for the case when a momentum wheel is used to consider alternative options for passive stabilization in terms of the inertial properties. Then a controller based on the Asymptotic Periodic Linear Quadratic Regulation (AP LQR) theory, the currently most extended and e ective for pure magnetic control in small satellites, is assessed. Also a Liner Quadratic Regulator design by means of numerical optimization methods, which has not been used in any real mission, is considered and its performances compared with the AP LQR. Regarding attitude determination a Linear Kalman Filter is designed using the AP LQR theory. Finally, a robustness analysis is conducted via Monte Carlo simulations for those control and determination strategies.<br>Systemet for attitydstyrning och -bestamning i nanosatelliten MIST reekterar sma satelliters begransningarna i utrymme, elkraft och omborddatorkapacitet. Regleringen ar begransad till styrning med magnetspolar som genererar kraftmoment. For attitydbestamningen anvands magnetometrar och solsensorer trots under-manovrering och -bestamning vid solformorkelse. Vanligtvis misslyckas sma satelliter med liknande reglersystem och hoga krav, sa om MIST lyckas skulle den bli ett referenskoncept. Malen med detta examensarbete ar att utfora en genomforbarhetsstudie av ett reglerkoncept for att mota de nominella kraven for MIST samt undersoka av alternativa reglersystem. E ekten av gravitationsstabilisering och olika masstroghetskongurationer har analyserats med hjalp av linjariserade stabilitetsregioner for en nadirpekande satellit. Stabilitetsregionerna forstoras da ett roterande hjul infors i ett alternativt stabiliseringskoncept eftersom det roterande hjulet paverkar de e ektiva masstroghetsmomentet. Regleringsalgoritmen som utvarderats i detta arbete ar baserad pa teorin om Asymptotisk Periodisk Linjar Kvadratisk Regulering (AP LKR), den som ar mest anvand samt e ektiv for ren magnetisk styrning av sma satelliter. En utformning av ett koncept baserat pa Linjar Kvadratisk Reglering med numerisk optimering, vilket inte tidigare verkar anvants for ett riktigt rymduppdrag, har undersokts och jamforts med AP LKR-regleringen. Nar det galler attitydbestamningen sa har ett linjart Kalmanlter utformats for AP LKR-regleringen. Slutligen sa har en robusthetsanalys gjorts genom Monte Carlo-simuleringar for styrnings- och bestamningsstrategierna.<br>El concepto para el ADCS en MIST reeja las limitaciones de los CubeSats en cuanto a espacio, potencia y capacidad computacional del ordenador a bordo. El control esta restringido al uso de solo magnetopares y la determinacion a magnetometros y sensores de Sol a pesar de la imposibilidad de actuacion segun todos los ejes y el conocimiento incompleto en actitud durante eclipses. Normalmente peque~nos satelites con un ADCS similar y exigentes requisitos fallan, por la tanto MIST sera una referencia de dise~no para este tipo de concepto en el caso de que tenga exito. Los objetivos de este trabajo n de master son la evaluacion de la viabilidad del concepto para cumplir los requisitos nominales en MIST y la consideracion de alternativas. Primero, la importancia de la estabilizacion gravitacional y diferentes conguraciones para las propiedades masicas son analizadas en base a las regiones de estabilidad lineales para vehculos espaciales apuntando segun nadir. Ademas, regiones de estabilidad extendidas son deducidas para el caso en el que una rueda de momento es usada con el n de considerar opciones alternativas de estabilizacion pasiva en terminos de las propiedades masicas. Despues un controlador basado en la teora del Asymptotic Periodic Linear Quadratic Regulation, el actualmente mas extendido y efectivo para control magnetico puro en peque~nos satelites, es evaluado. Tambien un dise~no de LQR por medio de metodos de optimizacion numerica, el cual no ha sido usado en ninguna mision real, es considerado y sus prestaciones comparadas con el AP LQR. En relacion a la determinacion de actitud un Linear Kalman Filter es dise~nado usando la teora del AP LQR. Finalmente, un analisis de robustez es llevado a cabo a traves de simulaciones de Monte Carlo para esas estrategias de control y determinacion.
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Cheney, Liam Jon. "Development of Safety Standards for CubeSat Propulsion Systems." DigitalCommons@CalPoly, 2014. https://digitalcommons.calpoly.edu/theses/1180.
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The CubeSat community has begun to develop and implement propulsion systems. This movement represents a new capability which may satisfy mission needs such as orbital and constellation maintenance, formation flight, de-orbit, and even interplanetary travel. With the freedom and capability granted by propulsion systems, CubeSat providers must accept new responsibilities in proportion to the potential hazards that propulsion systems may present.
The Cal Poly CubeSat program publishes and maintains the CubeSat Design Specification (CDS). They wish to help the CubeSat community to safety and responsibly expand its capabilities to include propulsive designs. For this reason, the author embarked on the task of developing a draft of safety standards CubeSat propulsion systems.
Wherever possible, the standards are based on existing documents. The author provides an overview of certain concepts in systems safety with respect to the classification of hazards, determination of required fault tolerances, and the use of inhibits to satisfy fault tolerance requirements. The author discusses hazards that could exist during ground operations and through launch with respect to hazardous materials and pressure systems. Most of the standards related to Range Safety are drawn from AFSPCMAN 91-710. Having reviewed a range of hypothetical propulsion system architectures with an engineer from Range Safety at Vandenberg Air Force Base, the author compiled a case study. The author discusses many aspects of orbital safety. The author discusses the risk of collision with the host vehicle and with third party satellites along with the trackability of CubeSats using propulsion systems. Some recommendations are given for working with the Joint Functional Component Command for Space (JFCC SPACE), thanks to the input of two engineers who work with the Joint Space Operations Center (JSpOC). Command Security is discussed as an important aspect of a mission which implements a propulsion system. The author also discusses End-of-Life procedures such as safing and de-orbit operations. The orbital safety standards are intended to promote “good citizenship.”
The author steps through each proposed standard and offers justification. The author is confident that these standards will set the stage for a dialogue in the CubeSat community which will lead to the formulation of a reasonable and comprehensive set of standards. The author hopes that the discussions given throughout this document will help CubeSat developers to visualize the path to flight readiness so that they can get started on the right foot.
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Furger, Steve M. "Analysis and Mitigation of the CubeSat Dynamic Environment." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1042.
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A vibration model was developed for CubeSats inside the Poly-Picosatellite Orbital Deployer (P-POD). CubeSats are fixed in the Z axis of deployers, and therefore resonate with deployer peaks. CubeSats generally start fixed in the X and Y axes, and then settle into an isolated position. CubeSats do not resonate with deployers after settling into an isolated position. Experimental data shows that the P-POD amplifies vibration loads when CubeSats are fixed in the deployer, and vibration loads are reduced when the CubeSats settle into an isolated position. A concept for a future deployer was proposed that isolates CubeSats from the deployer at the rail interface using viscoelastic foam sandwiched in the deployer rails. By creating an isolator frequency far below the deployer resonant frequency, CubeSats loads are not amplified at the deployer’s resonant peak. Feasibility tests show that CubeSat vibration loads can be reduced to 50% of the vibration input in certain cases. Testing also shows that it is much easier to define vibration loads for isolated CubeSats than CubeSats in the current P-POD.
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Haddock, Michelle. "Inductive Monitoring Systems: A CubeSat Ground-Based Prototype." DigitalCommons@CalPoly, 2015. https://digitalcommons.calpoly.edu/theses/1515.
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Inductive Monitoring Systems (IMS) are the newest form of health monitoring available to the aerospace industry. IMS is a program that builds a knowledge base of nominal state vectors from a nominal data set using data mining techniques. The nominal knowledge base is then used to monitor new data vectors for off-nominal conditions within the system. IMS is designed to replace the current health monitoring process, referred to as model-based reasoning, by automating the process of classifying healthy states and anomaly detection. An IMS prototype was designed and implemented in MATLAB. A verification analysis then determined if the IMS program could connect to a CubeSat in a testing environment and could successfully monitor all sensors on board the CubeSat before in-flight use. This program consisted of two main algorithms, one for learning and one for monitoring. The learning algorithm creates the nominal knowledge bases and was developed using three data mining algorithms: the gap statistic method to find the optimal number of clusters, the K-means++ algorithm to initialize the centroids, and the K-means algorithm to partition the data vectors into the appropriate clusters. The monitoring algorithm employed the nearest neighbor searching algorithm to find the closest cluster and compared the new data vector with the closest cluster. The clusters found were used to establish the knowledge bases. Any data vector within the boundaries of the clusters was deemed nominal and any data vector outside the boundaries was deemed off-nominal. The learning and monitoring algorithms were then adapted to handle the data format used on a CubeSat and to monitor the data in real time. The developed algorithms were then integrated into a MATLAB GUI for ease of use. The learning and monitoring algorithms were verified with a 2-dimensional data set to ensure that they performed as expected. The final IMS CubeSat prototype was verified using 56-dimensional emulated data packages. Both verification methods confirmed that the IMS ground- based prototype was able to successfully identify all off-nominal conditions induced into the system.
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Fitzsimmons, Sean. "Reliable Software Updates for On-orbit CubeSat Satellites." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/804.
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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 software updates.
This thesis details the design and development of such a feature-set with critical software recovery and multiple-mission single-CubeSat functionality in mind. As a result, features that focus on software update usability, validation, system recovery, upset tolerance, and extensibility have been developed. These include backup Linux kernel and file system image availability, image validation prior to boot, and the use of multiple file system devices to protect against system upsets. Furthermore, each feature has been designed for usability on current and future missions.
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Munsill, Caleb Mosby. "CubeSat Data Transmission and Storage Throughput Optimization Through the Use of a Zynq SoC Based CubeSat Science Instrument Interface Electronics Board." DigitalCommons@CalPoly, 2017. https://digitalcommons.calpoly.edu/theses/1736.
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The CubeSat standard sprang from the desire to create a satellite standard that would open the doors for universities and other lower budget research institutions by making it more feasible to get their work into space. Since then, many other institutions and industries have been adopting variations on the standard for their own use. As more people are seeking out to use the CubeSat standard as their main bus, the standards and practices of the community have grown and expanded and with this growth, new challenges have been created. One such challenge is the bandwidth limitation in the RF-downlink. When carrying payloads requiring what might seem to be a relatively small (science data) bandwidth requirement (on the order of thousands of bps), the RF-link to ground is overloaded. Many approaches in the past have been put forth to help alleviate this issue, unfortunately, none have been fully adopted. This paper presents a solution that takes advantage of new technology yet to be fully exploited in space applications. The key to the solution lies in removing the bandwidth requirements by enabling onboard post-data processing and compression. In order to achieve the high computational needs, while minimizing power consumption, a Xilinx Zynq-7000 SoC is used, creating a highly-programmable, open integration device. This report outlines the design, fabrication and testing of this solution. The completion of the Zynq Processing System CubeSat Science Instrument Interface Electronics Board (or ZPS-Board), ultimately demonstrates the feasibility of this solution. Additionally, this research is funded by NASA’s JPL, with secondary motives for the creating of a space application Zynq-7000 SoC based product. Upon successful completion of the ZPS-Board, the product creates a platform for JPL to perform environmental testing in order to study the effects and performance characteristics of the Zynq in space applications.