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The Sensor Research Laboratory (SRL) at the Naval Postgraduate School (NPS) is conducting research on terahertz (THz) imaging for space applications. The approach is two-fold: a commercial-off-the-shelf long-wave infrared (LWIR) camera using uncooled microbolometer technology has been modified with THz optics; and THz-to-IR band converter focal plane arrays have been developed to work as an attachment to the IR cameras. The small form factor of these technologies has enabled the Space System Academic Group at NPS to develop a CubeSat payload based on the THz imaging camera (TIC). The objective of this technology demonstrator is to examine the potential imaging capability in the THz range in the space environment, as THz radiation can penetrate many common gases, non-polar liquids, and non-metallic solids. In preparation for an upcoming launch opportunity in 2022, confidence testing has been performed on an engineering development unit of the TIC, and a concept of operations has been developed to capture low-resolution images in both the IR and THz ranges. There is unexplored potential for THz imaging, and this mission is a first step towards enabling additional imaging capabilities for applications such as submillimeter astronomy, space situational awareness, rendezvous and proximity operations, and possibly satellite inspection.

The Operationally Unique Technologies Satellite (OUTSat), the Government Experimental Multi-Satellite (GEMSat), and the Unique Lightweight Technology and Research Auxiliary Satellite (ULTRASat) missions, launched in 2012, 2013, and May 2015, successfully deployed a total of 33 CubeSats from Poly-Picosatellite Orbital Deployers (P-PODS) mounted to the Naval Postgraduate School (NPS) CubeSat Launcher (NPSCuL) on the aft end of the Atlas V Centaur upper stage. An additional 13 CubeSats are scheduled to launch on the Government Rideshare Advanced Concepts Experiment (GRACE) in September 2015. Force-limited vibration testing (FLVT) has been effective on all four missions in reducing the low-frequency vibration test environment at the P-POD interface on NPSCuL; however, the CubeSats were still subjected to high-frequency amplifications from the NPSCuL structure. Implementing commercial-off-the-shelf (COTS) isolators at the base of the NPSCuL structure has recently been shown to significantly reduce the high-frequency amplifications. This paper discusses the testing and the resulting 35-85% drop in overall G(RMS) vibration test levels, a welcome reduction in the CubeSat vibration test envirionment on NPSCuL. This reduction should allow more sensitive payloads to fly on future NPSCuL missions, and the implementation of low-cost, COTS isolators could possibly be useful for other small satellites and CubeSat launch applications. NRO Office of Space Launch and Cube Sat Program Office. Approved for public release; distribution is unlimited.

Attitude control system failures are often mission ending even when the mission payload remains operational. In this dissertation, the concept of unscented guidance is applied to reorient a reaction wheel satellite in the absence of feedback from star trackers or an inertial measurement unit (IMU). It is shown that an open-loop maneuver, properly designed using optimal control theory, can be used to achieve terminal attitude errors that are comparable with closed-loop control in the presence of uncertainty in the satellite inertia tensor. Typically, coarse closed-loop control is used to achieve < 1 degree pointing accuracy before more accurate pointing is done using fine guidance sensors to close the loop for science acquisition. It is shown that reaction wheel maneuvers designed using unscented guidance can also achieve sub-degree pointing accuracy of the spacecraft, making control hand-off to a functioning fine pointing control mode possible. The approach presented here enables large angle attitude control to be recovered so that mission operations may be continued despite IMU or star tracker failures. DoD Space, Chantilly, VA 20151 Civilian, Department of the Navy Approved for public release. Distribution is unlimited.

The objective of the study was to develop the initial capabilities enabling the eventual automation of an antenna gain-to-noise-temperature (G/T) measurement process using a software defined radio. This research investigated how to improve the Mobile Cubesat Command and Control (MC3) network’s ability to remotely monitor a ground station’s health. Previous thesis work was leveraged to collect baseline data and process it using software created by the Space Dynamics Laboratory for the MC3 program. The thesis required hands-on use of the NPS MC3 ground station and other stations on the network. The results of this thesis demonstrate that a software defined radio is capable of collecting and processing radio frequency signals from the sun and cold sky to produce a G/T value with enough fidelity to assess the health of the station’s downlink radio frequency chain. Continued expansion of the collected frequency range by the software defined radio is recommended to provide a broader assessment of the antenna’s sensitivity to weak, space-borne signals. Lieutenant, United States Navy Approved for public release; distribution is unlimited.

The objective of this research was to design, build, and test the next iteration of a low-cost, high-bandwidth X-band software-defined radio (SDR). The flight version of this iteration of the payload will be integrated into a commercially provided 6U bus to transmit and receive data, commands, and telemetry between the satellite and the MC3 network. The spacecraft reference design included two other payloads and used the Astro Digital Corvus-6 bus as the baseline for defining payload-bus-ground interfaces. This project utilized MATLAB Simulink to program the SDR. The SDR will primarily operate in the store-and-forward mode for transmissions when in line-of-sight of a ground station. The up/down convert board was designed, and manufacturing options were explored. Additionally, this project finalized the mechanical enclosure and bus interfaces. The payload aimed to maintain a 0.5U CubeSat form-factor and achieve a data rate of up to 10 Mbps with 1e-5 bit error rate. Following design and construction, the hardware and software components were subjected to functional end-to-end testing to evaluate performance. Further flight qualification will subject the payload to environmental testing to ensure survivability through launch and the expected low-Earth orbit environment. Lieutenant, United States Navy Approved for public release. distribution is unlimited

The Naval Postgraduate School (NPS) Small Satellite Lab places heavy emphasis on the research, development, and integration of emerging technologies on future spacecraft. An integral part of the advancement of these technologies is the ability to test them in real-world environmental conditions. CubeSats remain a viable choice for rapid prototyping and proof-of-concept testing. Delivering CubeSats to near-space environments is a method of demonstrating the feasibility of these new technologies. Amateur high-power rocketry offers an additional platform to augment the already existing high-altitude balloons by delivering payloads containing the new technologies and CubeSat form factor small satellites to near-space environments. Previous NPS research has produced a single stage high-power rocket capable of attaining an approximate altitude of 11.9 km (39,000 feet) above ground level. This thesis applies optimal control theory to develop a multi-stage rocket capable of altitudes in excess of what was previously reached by both high-altitude balloons and the previously designed high-power rocket. Lieutenant, United States Navy Approved for public release. distribution is unlimited

Empirical heat transfer values and thermodynamic models were verified and expanded for a uni-element film-cooled liquid rocket engine operating on a gaseous oxygen and RP-1 mixture. This effort was motivated by the likely reduction of the overall engine mass by integrating regenerative cooling channels directly into the combustion chamber and nozzle walls through the use of additive manufacturing. The data was collected for a range of operating conditions from 1.77 to 2.29 oxidizer-to-fuel mass mixture ratio and 9.65% to 19.69% film cooling. The combustion chamber of the engine experienced damage at heat flux values of 4.54 MW/m2 that occurred at a chamber pressure of 6.96 MPa, a mixture ratio of 2.0, and 9.59% film cooling. The data collected was used with computational tools to develop a novel integrated chamber-nozzle engine design for both regenerative cooling and film cooling conditions. The final design possessed less than 6% variation of flow though the 18 regenerative liner passages and was predicted to be able to handle the current and expected heat transfer values. The unit was printed using Stainless Steel 17-4PH with additive manufacturing techniques but will need to be qualified with future open and closed-loop testing to evaluate the delivered regenerative cooling effectiveness. Captain, United States Marine Corps Approved for public release. distribution is unlimited

Channel-response-based physical-layer authentication systems are challenged by the use of millimeter-wave frequencies for wireless communications due to the reduced coherence time and the sparsity of multipath components typically encountered. We examine how such an environment makes the assumptions of previous works in physical-layer authentication unrealistic, and present an approach that can tolerate such challenges by anticipating channel-response features based on relatively simple environmental survey information and location information of the communicating nodes. In addition to its resilience to millimeter-wave channel phenomena, such an approach has the advantage of being independent of an alternative initial authentication mechanism, distinguishing it from the majority of previous channel-based physical-layer authentication works and enabling its use in multi-factor authentication. Our work examines to what extent multipath time delays caused by planar specular reflectors enable the authentication of a wireless user’s reported position. Our formulations are supported via simulation of multiple environments, and the efficacy of the proposed scheme is supported via analysis of its information entropy and the likelihood that a masquerading attempt will be inadvertently authenticated. The analysis indicates useful information entropy and miss rates can be achieved provided measurement error is adequately bounded. http://archive.org/details/gmillimeterwavep1094564010 Lieutenant Commander, United States Navy Approved for public release; distribution is unlimited.

The configurable fault-tolerant processor (CFTP) project was intended to develop the means for a system to operate in areas which include frequent single-effect events (SEEs) similar to those caused by ionized radiation colliding with logic gates. Such errors are capable of degrading the functionality of a system and completely changing a state machine, such as is at the heart of most spacecrafts’ processors. The method for this consisted of a field-programmable gate array (FPGA) being designed into a system which is capable of detecting and then correcting SEEs. The system was designed by many students. This project will take that design, which launched into space earlier this year, and reduce it to modules which can be uploaded individually, built around a core which will be part of the existing triple fault-tolerant design (TFTD). Modularizing the code allows more experiments to be simultaneously performed in the future by changing the architecture of the system to upload specific modules to specified addresses. This will allow smaller uploads and code tweaks, without incurring long upload times, and more frequent updates to run specific tests ad hoc. Research and development conducted for this thesis has demonstrated the capability to inject configuration errors into the current design and the TFTD’s ability to detect those and similar errors, contributing to a better understanding of the TFTD. http://archive.org/details/modularizationof1094563984 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

Software-defined radios (SDRs) are used in many communications applications and offer flexibility in designing a communication network by offering rapid configuration changes after the radio is already produced. This is of interest in the small satellite industry, where small, lightweight, low-cost, and programmable radios will be needed for a wide array of upcoming missions of increasing complexity. Previous Naval Postgraduate School (NPS) research has produced a C-band SDR payload in a 1U CubeSat form factor. The X-band of the radio frequency spectrum offers more bandwidth, and opens the possibility of higher data rate transmissions. The objective for this project was to build an X-band SDR that can be used in future NPS research and flown on multiple platforms, including high altitude balloons, high altitude rockets, and CubeSats. This project built on previous C-band SDR research by converting the transmissions to X-band, expanding the over-air software protocol, implementing a new waveform, increasing the over-air data rate, and assessing the overall performance of the system. DoD Space http://archive.org/details/xbandsoftwaredef1094563431 Outstanding Thesis Lieutenant Commander, United States Navy Approved for public release; distribution is unlimited.

This study examines how to reconstruct a satellite decryption process from source information. It examines how cryptographic algorithms are implemented in software and what software components are required to access data in a useable format. This examination enabled the reverse engineering and reconstruction of the decoding processes utilized by the three PropCubes: Merryweather, Fauna, and Flora. Transmitted data from these PropCubes was analyzed to verify the validity of the developed decryption and data handling Python scripts. A concept of operations for implementing the reconstructed decryption and data handling processes in real-time is discussed in this research. http://archive.org/details/reconstructionof1094562698 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

Within the NPS Small Satellite Lab, research and development of emerging technologies and their implementation as CubeSat payloads has continued to be a focus of hands-on, lab-based academics. Testing of these student-built CubeSats in real-world environmental conditions began with the high-altitude balloon project in which large Nomex weather balloons were used to carry student-built CubeSat payloads to near-space altitudes. Since the inaugural flight in 2011, the high-altitude balloon project has generated interest from both senior civilian and military leadership, as the academic and military utility of such a program is readily apparent. Building upon the success of the program, this thesis seeks to complement the capabilities of the high-altitude balloon as an academic education tool and military payload delivery vehicle through the development of a high-power rocket program within the NPS Space Systems Academic Group. In addition to providing procedures and documentation as to the requirements for establishing a high-power rocket program, this thesis details the design, construction, and proof-of-concept flight of a reusable rocket capable of delivering standard dimension payloads to near-space altitudes. Results from several rocket flights are then used to explore the academic and military utility of a sustainable high-power rocket program. http://archive.org/details/developmentofaro1094562696 Outstanding Thesis Captain, United States Marine Corps Approved for public release; distribution is unlimited.

The current Department of Defense (DoD) satellite communications (SATCOM) network consists of large, exquisite, and expensive constellations providing service across the radio frequency spectrum. However, the current SATCOM architecture is vulnerable to adversary actions including interference, jamming, directed energy, and antisatellite weapons. Despite the rise in adversary threats, the DoD continues to grow more reliant on SATCOM services in execution of all seven joint warfighting functions. The Marine Corps Operating Concept acknowledges that traditional beyond line-of-sight (BLOS) communications capabilities will be severely degraded or non-existent in the future fight. This research demonstrates a near-term solution that increases resiliency in BLOS communications consisting of a rocket-delivered expeditionary narrowband radio relay with an applicable use case. The payload of the relay consists of a software-defined radio controlled by a single-board computer and demonstrates resiliency by cross-banding signals between very high frequency and ultra high frequency transmit and receive frequencies, respectively. After a rigorous design and test process, this research culminated with an actual demonstration over the air and an attempted delivery by an actual rocket to a target altitude of 30,000 feet. http://archive.org/details/fillingthegaproc1094562697 Major, United States Marine Corps Approved for public release; distribution is unlimited.

With traditional radio frequency (RF) bands becoming congested and the Department of Defense (DoD) expanding its efforts in the field of small satellites, the need for an on-orbit software-defined radio (SDR) has emerged. SDRs are a compact, off-the-shelf, low-cost, low-risk options for small satellite communication and can provide the flexibility of on-orbit configurability. This study includes the research toward the development of an on-orbit SDR CubeSat payload that can transmit on X-band spectrum (8–12 GHz). This band of interest can provide higher data rates and more bandwidth. Work in CubeSat transmitters and receivers supports development of national capabilities in space of benefit to warfighters. The payload designed, built, and tested for this research is called Com-Cube. Com-Cube utilizes hardware components and software considered for incorporation into a future CubeSat payload. Com-Cube was tested on a low altitude balloon (LAB) flight and demonstrated the transmission of images taken in-flight to a ground station via an amateur radio C-band frequency (5.75 GHz). This work directly supports a transmitter and receiver needed for future telemetry, tracking, and command (TT&C) and payload applications in the field of small satellites. This type of payload provides a test platform for further NPS research in the Mobile CubeSat Command and Control (MC3) ground station network operations and broadcast and receive experiments at frequencies of interest. http://archive.org/details/softwaredefinedr1094561218 Outstanding Thesis Lieutenant, United States Navy Approved for public release; distribution is unlimited.

In the next few years, the Space Systems Academic Group (SSAG) and the Small Satellite Laboratory at the Naval Postgraduate School (NPS) may begin work on a small satellite swarm constellation. This thesis introduces flight operations concepts for small satellite formations conducting sparse aperture radar missions to inform decision makers at NPS of possible flight operations options. An orbital modeling program called Systems Tool Kit was used to simulate combinations of flight patterns and orbits, including a pendulum and a helix inline hybrid model, and a cartwheel hybrid model. The MATLAB software package was used to plot the simulated orbits, calculating the flight formation stability, and for calculating the relative effects of sensor separation on the system resolution. Findings include a stable dispersion pattern for the satellites to conduct their mission and an ability to maintain safe, collision-free flight operations. http://archive.org/details/smallsatellitesw1094561306 Major, United States Army Approved for public release; distribution is unlimited.

To address the growing population of small satellite constellations that rely on distributed ground station networks, a dynamic optimization problem is formulated and solved. Specifically, this dissertation addresses the problem formulation, algorithm implementation, and experimental techniques developed to optimally slew ground-based antennas between multiple satellites that are simultaneously in view of one or more earth stations. The problem is solved using DIDO, a MATLAB optimal control solver, to produce deconflicted ground antenna slew trajectories. The deconfliction parameters include space-to-ground link budgets, mission priority, asset availability, and onboard health. Traditional methods employ heuristics to generate a subset of available targets and a separate process to check feasibility of the solution. The method described in this dissertation deterministically solves the problem in a single step. The approach is experimentally validated and tested using a small constellation of low-Earth-orbiting CubeSats operated by the Small Satellite Laboratory at the Naval Postgraduate School, using the Mobile CubeSat Command and Control (MC3) ground station network. http://archive.org/details/resourceconstrai1094560435 Civilian, Department of the Navy Approved for public release; distribution is unlimited.

This thesis builds on the existing research of the Sensor Research Laboratory and the Space Systems Academic Group (SSAG) at the Naval Postgraduate School (NPS) to integrate an 80-micron terahertz (THz) imaging camera (TIC) as a CubeSat payload. This research investigates the potential utility of THz imaging and long-wave infrared (IR) imaging at room-temperature (20°C) cooling for applications of national interest like space situational awareness (SSA). Long-wave IR imaging capability already exists, and typically requires a large cryocooler to maintain cryogenic temperatures (3–70 K); efficient IR imaging at room temperature is an emerging technology. Additionally, this thesis examines the integration and test effort associated with flight qualifying the TIC engineering development unit (EDU) onto the SSAG-developed High Altitude Balloon (HAB) bus. This thesis contributes to the overall objective of integrating and flight qualifying the TIC as a payload compatible with a variety of buses. Integrating and testing the TIC EDU on a CubeSat attains focused research objectives of national interest and supports Department of Defense Space efforts in the utilization of very small satellites. DoD Space http://archive.org/details/flightqualificat1094559702 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

A satellite to be used as a testbed for experiments such as the Configurable Fault Tolerant Processor (CFTP) was designed at the Naval Postgraduate School. This processor consists of a Field Programmable Gate Array (FPGA), which may be reprogrammed by receiving a signal from a source external to the satellite. Experimentation of a high-speed pipelined and fault tolerant Fast Fourier Transform (FFT) was conducted for use within the CFTP. In this thesis, we detail the development and testing of a high-speed pipelined FFT in which fault tolerance can be applied at a later opportunity. Xilinx Vivado ISE® was utilized to synthesize behavioral Verilog to program an FPGA. Xilinx Vivado ISE’s® simulation suite produced waveforms to demonstrate functionality. Launch of CFTP is planned for FY18 aboard NPSat-1. http://archive.org/details/implementationof1094559613 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

This thesis contributes to the growing body of research concerned with the issue of the increasing numbers of government small satellites (SmallSats) and the limited number of ground stations available to support these missions. To understand this “many satellite, few ground station” problem, a Monte Carlo simulation is used to identify the point at which a single ground station is expected to be overwhelmed, specifically looking at the case of the Mobile CubeSat Command and Control (MC3) ground station at the Naval Postgraduate School (NPS). Ground station saturation is defined in terms of data downlink requirements and the increasing number of conflicting passes as the number of SmallSats grows. An assessment of when one ground station becomes insufficient for a growing number of SmallSats is the result. The MATLAB software tools created to generate these scenarios are generic and can be used to extend this work to investigate other scenarios of SmallSats and multiple ground stations. http://archive.org/details/optimizationofcu1094559624 Captain, United States Marine Corps Approved for public release; distribution is unlimited.

Electromagnetic (EM) spectrum management is an escalating concern in today’s growing wireless market, and ensuring that the growing number of EM spectrum users have adequate access will become only harder and more expensive as the number of users of cellular phones and satellite operations continues to grow. Utilizing and effectively sharing available spectrum is an involved process with many users competing for access. With the ever-increasing demand for EM spectrum, the creation and utilization of policies and regulations that support and encourage the co-utilization of EM spectrum bands is of growing importance. The Mobile CubeSat Command and Control (MC3) ground station personnel at the Naval Postgraduate School (NPS) in Monterey, California, conducted a series of tests with local news station KION to determine the feasibility of simultaneously using an S-Band uplink frequency to conduct telemetry, tracking, and communications (TT&C) with NPS CubeSats while KION conducted its electronic news gathering (ENG) operations. The testing determined that conducting TT&C satellite operations above 7 degrees of antenna elevation does not impact ENG operations in Monterey. Our results may encourage spectrum co-utilization and ease the strain on the increasingly congested EM spectrum. http://archive.org/details/sharingsbandcomm1094558295 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

Space is a harsh environment, full of high-energy radiation that can cause single-event effects (SEE) in orbiting satellites. Some of these effects, such as single-event upsets and single-event functional interrupts, occur when ionizing radiation causes the logical value in a memory element to change and are detectable and correctable through various error mitigation techniques. In this thesis, we develop and implement a hardware solution to combat these SEE for deployment as an experimental module on Naval Postgraduate School Satellite 1 (NPSAT-1). Based on the relatively benign orbit of NPSAT-1, industrial-grade, commercial-off-the-shelf components that have shown tolerance to radiation were selected to keep costs low. The primary source of mitigation relies on a globally triple-modular redundant microprocessor system instantiated inside of a XILINX Kintex-7 field-programmable gate array. The system consists of an open-source microprocessor without interlocked pipeline stages (MIPS) based processor softcore, a cached memory structure capable of accessing double-data rate type three and secure digital card memories, an interface to the main satellite bus, and XILINX’s soft error mitigation softcore. The hardware was tested both in and out of the system and verified to work on the ground with faults injected. Other techniques to mitigate errors due to SEE, such as memory scrubbing, are intended to be added before launch. http://archive.org/details/implementationof1094548536 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

Reissued 10 Jan 2017 with corrected degree. Force-limited vibration testing (FLVT) is effective in reducing the low-frequency vibration test environment for CubeSats on the Naval Postgraduate School CubeSat Launcher (NPSCuL); however, the CubeSats are still subjected to high-frequency amplifications above 500 Hz from the NPSCuL structure. The excessive, high-frequency vibration has caused test failures and forces CubeSat developers to focus more on surviving environmental testing instead of developing state-of-the-art technology. Whole-spacecraft isolation systems are often used to reduce these amplifications, but they currently exist only for large spacecraft and are too expensive to adapt for small satellites. These limitations motivated the combined use of FLVT and commercial-off-the-shelf (COTS) isolators on NPSCuL as a novel, practical, and low-cost method to reduce vibration levels for small satellites. This method significantly reduces the high-frequency amplification by up to 97%; the root-mean-square acceleration (GRMS) over the entire test frequency range drops by up to 78%. These results should allow more sensitive and complex payloads to gain access to space on future NPSCuL missions and demonstrate how a worst-case environment on a small satellite can be improved. Implementing low-cost, COTS isolators on other small satellites and CubeSat launch applications could be useful as well. http://archive.org/details/developmentoflow1094547804 Civilian, Department of the Navy Approved for public release; distribution is unlimited.

This thesis solves the problem of a lack of a complete, simple ground station network interface standard. A federated satellite ground station network (FGN) model and computer interface are developed that extend the use of ground stations to external users across the Internet. This should allow for reuse of existing ground stations, reducing costs and complexity of space missions. An improved model describing FGNs is proposed that defines a hierarchy of the components of the network, allowing for scalability and unified interfaces, and simplifying the process of using FGN resources. This model, which we call the Improved FGN model, is used to develop security schemes that are simple but effective. Simple but effective security schemes are then developed for this Improved FGN model, along with a standardized SOFtware interface. This interface connects external users to the network in order to extend ground station hardware to remote users as well as to simplify scheduling for the resource owners in a network. Different middleware frameworks are compared, and Apache Thrift is selected as the best fit for an FGN. This interface is then described and demonstrated with a reference implementation in Python. Recommendations for future improvements of this interface standard are discussed. http://archive.org/details/federatedgrounds1094544558 Civilian, Department of the Navy Approved for public release; distribution is unlimited.

The Naval Postgraduate School Solar Cell Array Tester (NPS-SCAT) is the first CubeSat for the Naval Postgraduate School (NPS). The NPS-SCAT mission was designed to measure solar cell performance degradation in low earth orbit. NPS-SCAT serves as a pathfinder for future NPS CubeSat missions. This thesis documents the pre-flight NPS-SCAT battery analysis, power budget, vibration analysis, beacon antenna integration evaluation, and conformal coat study. Some data from the flight is presented, which validates the pre-flight power budget analysis. http://archive.org/details/npssolarcellarra1094543925 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

The Naval Postgraduate School CubeSat Launcher (NPSCuL) is a five-sided structure capable of carrying up to 24 CubeSats to orbit. The vibration test environment for CubeSats flying on NPSCuL on the Atlas-V is extremely harsh, partly due to the input vibration environment from the launch vehicle itself, and partly due to amplification from the NPSCuL structure. This thesis documents the implementation of a relatively new technology, Force Limited Vibration Testing (FLVT), and the design of a stiffer structure to reduce the vibration environment for NPSCuL payloads. Most acceleration-controlled vibration tests result in significant over-test. FLVT limits shaker forces, producing more realistic tests and potentially provides relief to payloads. Additionally, increasing the stiffness of NPSCuL using an isogrid design, aimed to increase its first-fundamental frequency, could result in less displacement at higher frequencies for a given amount of input energy, possibly improving the payload vibration environment. It was found that FLVT was very successful in reducing vibration environments for NPSCuL payloads. Although redesigning NPSCuL using an isogrid design achieved the goal of increasing system stiffness, it did not reduce the vibration environment. None the less, lessons learned from the redesign process will be valuable for continuing vibration environment reduction efforts. http://archive.org/details/forcelimitedvibr1094542656 Civilian, Department of Defense Approved for public release; distribution is unlimited.

The purpose of this thesis is to design and test a fault–tolerant reduced instruction set computer processor running a subset of the multiprocessor without interlocked pipelined stages instruction set. This processor is implemented on a field programmable gate array (FPGA) and will be used as the foundation for a payload processor on a cube satellite developed at the Naval Postgraduate School. This thesis begins by considering the radiation effects present in the space environment and the various fault– tolerant designs used to guard against specific types of particle events. The internal triple modular redundancy method is selected and implemented at each pipeline stage of the processor. Next, a target FPGA is selected based on the performance requirements of the processor. The Virtex–5 (registered trademark of Xilinx, Inc.) is selected over the ProASIC3 (registered trademark of Microsemi, Inc.) due to its enhanced capabilities and potential to support expansion for future applications. The hardware design is presented as a hybrid Verilog and schematic based design. The system consists of the processor and a universal asynchronous receiver/transmitter that reads and writes data received from a generic serial interface. The device is simulated to ensure proper logic functionality. Conclusions and future work are discussed. http://archive.org/details/adaptationoffaul1094542634 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

The Mobile CubeSat Command and Control (MC3) architecture is a growing network of ground stations that spans the United States of America. It was designed to support the National Reconnaissance Office’s Experimental CubeSat Program. Each node was originally designed to communicate via UHF and S-band frequencies using Yagi antenna only. The MC3 ground station at the Naval Postgraduate School has recently incorporated a 3-meter S-band dish. This thesis documents the calibration and capabilities of the new S-band dish. It also investigates the possibility of using the antenna outside of its normal operating range. In particular, the idea of using an S-band, 3-meter dish to receive UHF band signals was tested by designing a UHF signal feed optimized for 915 MHz and used to listen to a UHF source deployed on a high altitude balloon at near orbital distances. In addition, this document discusses the integration of a dish system into current and future MC3 ground stations. http://archive.org/details/mobilecubesatcom1094542572 Major, United States Marine Corps Approved for public release; distribution is unlimited.

The design of a device that controls the sequence and timing of deployment of CubeSats on the Naval Postgraduate Schools CubeSat Launcher (NPSCuL) is detailed in this thesis. This design is intended to be implemented on a field-programmable gate array (FPGA) installed into the NPSCuL. This configuration allows flexibility in reprogramming the launch sequence and adding additional functionality in future designs. Operating an FPGA on orbit presents unique challenges due to the radiation environment. Radiation from space cannot be shielded efficiently, so devices must be tolerant of the expected effects. The most common effect, the single-event upset can have detrimental effects on operating electronics, causing undesired changes to data. To combat this problem, fault tolerant techniques, such as triple-modular redundancy (TMR) are explored. In these methods, multiple redundant copies of the design are operated simultaneously, and the outputs are voted on by special circuits to eliminate errors. Comparisons between manual and software generated TMR methods are tested, and the design is implemented on test hardware for further verification. Finally, future research and testing is discussed to continue to ready the design for employment of the sequencer on an actual space mission. http://archive.org/details/faulttolerantseq1094538884 Lieutenant Commander, United States Navy Approved for public release; distribution is unlimited.

This thesis contains the results of a complete redesign effort, including development, integration, and experimental testing of a very small mechanical coupling mechanism. This mechanism is suitable for nano-satellites and uses a shape memory alloy (SMA) ring, press-fit into a metallic bushing to create a releasable interference joint. A detailed explanation of the techniques used to press-fit the SMA ring into the metallic bushing is included along with a description of why the SMA ring shrinks to its austenite phase upon heat activation and how it decouples from the metallic bushing. The couplingengineered to be as small as one tenth of a cubic centimeteris capable of achieving holding strengths in excess of 135 N (30 lbf). SMA characteristics and current release mechanisms are explained and tests are conducted to validate the holding strength achieved by the interference joint between the SMA and the metallic bushing. The design and part selection for each component of the Engineering Design Unit (EDU) is documented and launch conditions simulated to test the EDUs performance, releasability, and to validate the static holding force. Finally, this thesis describes the simulated integration of the EDU into a 3U CubeSat structure. http://archive.org/details/developmentinteg1094527887 Lieutenant Commander, United States Navy Approved for public release; distribution is unlimited.

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. http://archive.org/details/starecubesatcomm1094517397 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

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. http://archive.org/details/mobilecubesatcom109455591 Approved for public release; distribution is unlimited.

The Mobile CubeSat Command and Control (MC3) system provides ground support for the Colony II program. The combination of commercial off-the-shelf hardware with government off-the-shelf control software make for a low cost ground station solution. The Naval Postgraduate School will partner with select educational facilities to provide a world-wide footprint for Colony II satellite operations. To assist these partner facilities, the author created a detailed assembly and setup guide targeted to an average college student, a typical user for the MC3 ground station. This thesis captures the assembly process and documents lessons learned to help future operators of MC3 ground stations in their educational endeavors. Also included is an analysis and discussion of the Global Educational Network for Satellite Operations network and its suitability for performing the Colony II ground segment mission and possibly supplementing the MC3 network. http://archive.org/details/mobilecubesatcom109455522 Approved for public release; distribution is unlimited.

0.1°/sec, while the acceptance tests demonstrate the robustness and reliability of the unit. http://archive.org/details/npsatmemsaxisrat109455490 Approved for public release; distribution is unlimited.

This thesis describes the development of a working thermal model of the Naval Postgraduate School's first CubeSat called NPS-SCAT and the accomplishment of environmental testing that has been completed to date in preparation for space launch. The primary mission of NPS-SCAT is to act as a Solar Cell Array Tester (SCAT), providing data on solar cell performance of various solar cells in Low Earth Orbit (LEO). As part of the satellite development process, a detailed test plan was developed and environmental modeling and testing were completed to test SCAT's ability to survive and function in the space environment. A thermal finite element model (FEM) was developed in NX-6 I-deas to analyze and predict the component thermal response to the space environment. Environmental tests, including thermal vacuum (TVAC) and vibration testing, have been completed using profiles determined by the expected launch and on-orbit conditions. The data obtained from these tests validated the thermal model and proved that SCAT would survive the launch conditions and could successfully operate in the space environment. http://archive.org/details/environmentaltes109455654 Approved for public release; distribution is unlimited.

Space situational awareness is extremely important in order to maintain the safety and usability of earth-orbiting satellites, as well as protecting astronauts living and working in space. Traditional space situational awareness is achieved using ground-based radar and optical sensors. This thesis explores the feasibility of space-based space situational awareness using a 3U CubeSat with an optical imager to augment the Space Surveillance Network by capturing conjunctions in space, from which ephemeris data of earth orbiting objects can be updated to more accurately predict future orbital positions. Work completed includes preliminary work towards building, testing, and using a Colony II Bus emulator and interface mechanism, allowing smooth payload and bus integration. Analysis of orbital trajectories for a reference orbit and potential crossing satellites provides insight into the capabilities of the SSA CubeSat. Future work is discussed. http://archive.org/details/enhancingspacesi109455001 US Navy (USN) author Approved for public release; distribution is unlimited.

Worldview-2 spectral imagery acquired over Duck, NC and Pendleton, CA were analyzed to extract Bidirectional Reflectance Distribution Functions (BRDF) for 8 spectral bands. Spectral data in the visible and near-infrared bands were acquired for 15 azimuth/elevation values during the Duck NC orbit pass; data were collected at ten-second intervals. Ten images were acquired over Pendleton. Orthoready images were coregistered using first-order polynomials for the two image sequences. BRDF profiles have been created for scene elements: vegetation, asphalt, sand, and water. These data allowed for unique high-spatial resolution BRDF profiles, which can be used to inform terrain classification and target detection in satellite imagery. http://archive.org/details/highspatialresol109455102 US Navy (USN) author Approved for public release; distribution is unlimited.

The electrical power subsystem is one of the most important elements of any satellite. This system must provide the necessary power to enable the payload and other subsystems to perform their functions. Once spacecraft requirements are determined and an electrical power subsystem is chosen; extensive testing is required to ensure power subsystem performance. Testing of CubeSat Kit compatible power systems is especially difficult due to the inaccessibility of test points. This thesis concerns itself with the role that power and, in particular, power budgets play in very small satellites. As a practical application to facilitate power budget analysis of CubeSat Kit compatible CubeSats, a testing platform has been designed and built. Data from NPS-SCAT electrical power subsystem and other subsystems have been measured and the NPS-SCAT power budget analyzed and simulated. http://archive.org/details/electricalpowers109455000 US Navy (USN) author Approved for public release; distribution is unlimited.

This thesis describes the design, development, and testing of an innovative nonexplosive actuator (NEA) microcoupling device. The micro-coupling is obtained through the use of a nickel titanium (NiTi), shape memory alloy (SMA) cylindrical ring that is press-fit, in its detwinned martensitic phase, into a steel bushing, creating an interference joint. This SMA interference joint can subsequently decouple upon command, by heating the SMA cylindrical ring into its smaller austenitic memory shape, freeing it from its press-fit. The micro-coupling can be engineered to very small sizes, on the order of one cubic centimeter, and achieve coupling strengths in excess of 4,000 N (900 lbf). The SMA micro coupling's concept validation, mechanization, and development into a device for satellite incorporation are explored by assembly and experimentation. Research on pseudoelastic material properties, analytical predictions, and tests of coupling strengths are examined to characterize the SMA micro-coupling. While the micro-coupling's characteristics are desirable for many applications, its small size, simple interface, and lowpower zero-shock actuation are ideal for employment on nano-satellites to effectively increase space deployable actuation reliability by eliminating reliance on motors, clasps, latches, material fracture, or explosive devices. http://archive.org/details/developmentofnan109455015 US Navy (USN) author Approved for public release; distribution is unlimited.

Educating space professionals is an expensive endeavor. The use of technologies such as CubeSats can cut the cost giving space professionals real world experience in satellite design, testing, integration and operations. The Naval Postgraduate School-Solar Cell Array Tester (NPS-SCAT) will be the first of what may be many CubeSats developed by the Space Systems Academic Group, Small Satellite Laboratory. This thesis analyzes the NPS-SCAT program from the program managers point of view and provides an overview of the development of the program from an un-qualified Engineering Design Unit (EDU) to a fully qualified EDU. Also included in this thesis is a description of the subsystems and full cost analysis that covers the total costs from concept to flight unit. http://archive.org/details/navalpostgraduat109454990 US Navy (USN) author Approved for public release; distribution is unlimited.

This thesis presents the mass optimization of the Naval Postgraduate School Cube Satellite Launcher. The current structure weights 170.63 lbs and can hold up to 24 Cube Satellites. The weight of the whole system, which includes the launcher and all contained satellites, cannot exceed 177 lbs or be lighter than 169 lbs. By reducing the mass of the launcher, the freed weight can then be reallocated to the Cube Satellites. This will increase the maximum allowed weight per satellite. The current design has six pounds of available free weight. During the course of the analysis, it is found that removal of unused portions of the four side walls of the launcher structure will reduce the weight without undermining the strength. Additionally, when looking at the use of different metal options for the launcher, it is found that the structure needs to maintain the use of an aluminum alloy. Maintaining space-grade aluminum in conjunction with the removal of unused sections of the side walls frees an additional four pounds. This totals ten pounds that can be allocated back into the Cube Satellites. http://archive.org/details/improvingnpsculs109455201 US Navy (USN) author Approved for public release; distribution is unlimited.

The Naval Postgraduate School's first CubeSat, the NPS Solar Cell Array Tester (NPS-SCAT), demonstrates the capability of the CubeSat form factor as a technology test bed by implementing a single experiment--a solar cell tester. The need to validate solar cell performance on orbit, in the harsh space environment, is recurring with the continued development of advanced, untested solar cells. By using a relatively inexpensive platform, the CubeSat, such solar cells can be tested and the risk for larger satellites mitigated with this experiment. This thesis discusses the design and construction process of the solar cell array tester payload along with its integration with the remaining satellite subsystems (command and data handling subsystem, communications subsystem, and electrical power subsystem) including the problems encountered along the way and the chosen solutions. In addition, the systems engineering and testing procedures developed for and conducted on the satellite engineering design unit will be described in detail. http://archive.org/details/npsscatsystemsen109455283 US Navy (USN) author Approved for public release; distribution is unlimited.

The electrical power system (EPS) is an essential part of a satellite. It distributes, stores and generates the electric power for autonomous operation of the satellite in space. Through standardizations in the CubeSat community a common structure of EPS is established. The thesis explains both the functioning and the requirements of electrical power systems. Furthermore, two EPS are presented that are currently commercially available and have been use d in other CubeSats. The Naval Postgraduate School (NPS) is currently developing a lU Cubesat (NPS-SCAT) and the EPS board used has insufficient specifications for accurate operation. To avoid problems in the advanced stage of development, the EPS has to be simulated. This research lays the foundation for an EPS computer model based on PSpice simulation softwar. At the outset the design of a solar pan el and Lithium-Ion battery model was possible. In particular, the models are modifiable at any time so that technical changes can be incorporated as needed. Das elektrische Energiesystem (EPS) ist ein wesentliches Bauteil eines Satelliten. Es verteilt, speichert und erzeugt elektrische Energie den autonomen Betrieb des Satelliten im Weltraum. Durch die Standardiesierung in der CubeSatGemeinschaft hat das EPS einen typischen Aufbau. Die Arbeit erklart sowohl die Arbeistweise als auch die Anforderungen an das Energiesystem. Desweitern werden zwei kommerziell erhaltliche Systeme prasentiert, die schon für CubeSat Missionen eingesetzt wurden. Die Naval Postgraduate School (NPS) entwickelt momentan einen lU Cuebsat (NPS-SCAT) und das verbaute EPS Platine hat aber eine zu geringe Lei stung. Das solch ein Problem nicht in ein so fortgeschrittenen Stadium auftritt, ist es sinnvoll das EPS vorher zu simulieren. Die Ergebnisse dies er Arbei t legen die Grundlage für ein EPS Computermodell basierend auf einer Psice Simulationssoftware. Solarmodul und den Zurn Beg inn war es Lithium-Ionen-Akku ZU moglich das modellieren. Insbesondere wird wert darauf gelegt die Modelle jederzeit anpassen zu können, Insbesondere wird wert darauf gelegt die Modelle jederzeit anpassen zu können, um auf technologische Anderungen reagieren zu können. Helmut Schmidt University University of the Federal Armed Forces Hamburg Holstenhofweg 85, 22043 Hamburg g, German y 2nd Lieutenant, German Air Force (Luftwaffe) Approved for public release; distribution is unlimited.

When compared to other laser types, the Free Electron Laser (FEL) provides optimal beam quality for successful atmospheric propagation. Assuming the development and deployment of a mega-watt (MW) class, ground or sea based FEL, this thesis investigates several proposed space applications including power beaming to satellites, the removal of orbital debris, laser illumination of objects within the solar system for scientific study, and interstellar laser illumination for communications. Power beaming simulations are conducted within the Satellite Tool Kit (STK) program to determine the frequency of accesses between a satellite and one or more ground stations for multiple orbital profiles. FEL illumination of orbital debris is modeled to determine the thermal effects on a representative aluminum debris particle. FEL illumination of the Lunar and Martian surfaces is modeled to determine the relative laser and solar spectral intensities at these ranges. FEL illumination at interstellar ranges is modeled and discussed to determine our ability to communicate or detect laser communications over interstellar ranges. http://archive.org/details/powerbeamingorbi109455430 US Navy (USN) author Approved for public release; distribution is unlimited.

The Naval Postgraduate School Solar Cell Array Tester (NPS-SCAT) seeks to expand the CubeSat knowledge base and provide learning possibilities at the Naval Postgraduate School. This thesis discusses the design, testing, and integration of the electrical power sub-system for NPS-SCAT. The current design will be powered by a commercial-off-the-shelf power system developed by Clyde Space systems. Solar power generation will be via Spectrolab's improved triple junction solar cells. Satellite Tool Kit (STK) was used to approximate the expected power generation and communication periods while on orbit. The design, building and integration and testing of the solar panels using NuSil adhesive tape will also be discussed. Finally, the operational limits imposed on SCAT operations due to load and power generation capabilities of the electrical power system will also be discussed. http://archive.org/details/npsscatelectrica109454567 US Navy (USN) author. Approved for public release; distribution is unlimited.

In this study, the current and expected state of lunar landing technology is assessed. Contrasts are drawn between the technologies used during the Apollo era versus that which will be used in the next decade in an attempt to return to the lunar surface. In particular, one new technology, Autonomous Landing Hazard Avoidance Technology (ALHAT) and one new method, DIDO optimization, are identified and examined. An approach to creating a DIDO optimized lunar landing trajectory which incorporates the ALHAT system is put forth and results are presented. The main objectives of the study are to establish a baseline analysis for the ALHAT lunar landing problem, which can then be followed up with future research, as well as to evaluate DIDO as an optimization tool. Conclusions relating to ALHAT-imposed ConOps (Concept of Operations), sensor scanning methods and DIDO functionality are presented, along with suggested future areas of research. http://archive.org/details/didooptimization109454508 Department of Engineering and Applied Sciences, author (Civilian). Approved for public release; distribution is unlimited.

The purpose of this thesis is to document my activities related to managing the design, analysis, construction, testing, and integration of a qualification and, possibly, a flight article in support of the NPS CubeSat Launcher (NPSCuL) project. This thesis will describe the process, experience, and results of managing the NPSCuL program, including the program budget and schedule in support of a flight opportunity as early as August 2010. NPSCuL is designed to utilize excess capacity on U.S. launch vehicles to place a significant volume of CubeSats into orbit in a single launch. The NPSCuL will be a secondary payload attached to the launch vehicle via the EELV Secondary Payload Adapter (ESPA) or other compatible launch vehicle structures. The NPSCuL-Lite, a modified version of the NPSCuL, integrates eight Poly-Picosatellite Orbital Deployers (P-PODs) with a deployment sequencer in a simple structure. NPSCuL-Lite will be able to accommodate up to twenty-four units of CubeSat volume. The goal of the NPSCuL project is to improve CubeSat access to space, advance U.S. space technology, and ensure that the next generation of U.S. space professionals will remain on the cutting edge of very small satellite development. http://archive.org/details/npscubesatlaunch109454517 Outstanding Thesis US Navy (USN) author. Approved for public release; distribution is unlimited.

A small version of NPSCuL called NPSCuL-Lite will house CubeSats in up to 8-1x1x3 ("3U") Poly Pico-satellite Orbital Deployers (P-PODs) developed by the California Polytechnic State University (Cal-Poly). The sequencer's function is to issue commands and drive the circuitry to open the P-PODs in the proper sequence. The sequencer may be mounted either externally from the NPSCuL-Lite or internally. Both a functional flight-similar model, and a mass model of the correct size and CG, are required for future testing. http://archive.org/details/npscubesatlaunch109454771 RSPXL US Navy (USN) author. Approved for public release; distribution is unlimited.

C system. The thesis also explains the testing procedures of the transceiver and the design, test, and integration of the primary and secondary antennas. Finally the thesis explains the frequency licensing process through the Navy-Marine Corps Spectrum Center and the Federal Communications Commission. http://archive.org/details/npsscatcubesatco109454737 US Marine Corps (USMC) author. Approved for public release; distribution is unlimited.

Access to space has always been a challenge, especially for organizations with limited budgets. In the last decade a group of universities has overcome many of the obstacles associated with placing experiments on orbit by using a nano-satellite standard called the "CubeSat." In addition to universities many private, commercial, and government organizations are now coming to appreciate the advantages of the CubeSat standard resulting in rapid growth in the CubeSat development community. Although the CubeSat standard has helped increase access to space, the number of CubeSat launch opportunities has not increased at a rate necessary to meet demand since the hardware and processes necessary to do so do not exist. U.S. based CubeSat developers face additional challenges since almost all CubeSats are launched overseas.This thesis proposes a solution to the lack of CubeSat launch availability called the NPS CubeSat Launcher (NPSCuL).The NPSCuL is a high capacity CubeSat launch mechanism, which could facilitate rideshare opportunities onboard U.S. launch vehicles. This thesis studies the design, program management, and advantages associated with such a device, and promote its development at the Naval Postgraduate School. http://archive.org/details/npscubesatlaunch109454752 US Navy (USN) author. Approved for public release; distribution is unlimited.