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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

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.

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.

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.

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.

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 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 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.