In recent years, the Earth Observation (EO) industry has experienced rapid growth and development, but the tools to analyze EO constellations and space systems are lagging behind the curve. In particular, as costs continue to decrease to the point where constellations are treated like commodities, it is critical to look past cost and towards value creation when designing future EO constellations. In particular, there is an increasing need for value driven tradespace methods that can assist in the development of future EO space systems. Although there exist a few value driven approaches towards EO constellation design, they tend to be non-general and rely on detailed information such as expert knowledge or detailed probability distributions. Due to these limitations and the growing need for value driven trade methods, this thesis presents a new quantitative approach, using a novel Value Function, that can be applied generally to EO constellation trade studies. This thesis hypothesizes that the value generated by an EO constellation can be generalized in that the quantity and quality of data drives value to various stakeholders. By focusing on this simple hypothesis, this thesis will derive the Value Function to highlight these key attributes. The Value Function can be applied to a EO constellation, and using this new metric, various constellations can be compared against one another in a standardized way. To help show this, three case studies are used. The first case study, Case Study A, looks at two existing EO constellations: Landsat 8 and RapidEye. Their tradespaces are re-examined, and it is shown that the designs that are currently in operation are not optimal. There exists a single satellite Landsat-like architecture that generates 19.44% more value as compared to the current Landsat satellite in orbit. There also exists a five satellite RapidEye-like constellation that generates 35.76% more value as compared to the existing RapidEye constellation. The second case study, Case Study B, examines the make versus buy decision. In particular, it provides a hypothetical case study to determine if the Governor of California should purchase satellite imagery directly from Planet Labs, or if the state should fund a new constellation. This case study that shows the importance of understanding both costs and benefits when making important and high-investment decisions. For example, this thesis will discover an architecture that has 2 satellites, where each satellite is similar to a Planet Flock 2p CubeSat, and an orbital geometry that emphasizes California as compared to global coverage. The value ratio of this architecture is 5.01, and it is always greater than the cost ratio. This implies that it is in the state's best interest to build the constellation as opposed to purchasing imagery directly. Other architectures will be shown that do not lead to this same conclusion. The third case study, Case Study C, examines a proposed Synthetic Aperture Radar small satellite constellation, MicroX-SAR, by exploring a small set of potential architectures. These architectures are compared quantitatively using the Value Framework presented in this thesis, and it is shown that proposed constellations that are Sunsynchronous and at altitudes of 600 km generate the most value for a global region of interest. This information can be used when designing the mission parameters, such as orbital geometry, that will be important for constellation implementation. Overall, this thesis contributes a new model to evaluate EO constellations that relies on value driven methods as opposed to commonly used cost based metrics.

Earth observation (EO) satellites provide helpful imagery to a variety of applications ranging from weather monitoring to agricultural support. Disaster response imaging is an essential but difficult application for EO to support. Reconfigurable satellite constellations (ReCon) provide a flexible solution to the challenge of quickly providing imagery of unknown locations. ReCon leverages the natural shift of ground tracks due to the disparity between the Earth’s rotation and the period of an orbit to maneuver a constellation into repeating ground track (RGT) orbits. This maneuvering strategy relies on altitude changes to vary an orbit’s ascending node and mean anomaly, which both dictate the location of satellite’s ground track. Altitude changes require significantly less fuel than plane changes. Using ReCon allows for smaller constellations to provide high-performance imagery for disaster response for a lower cost. This work explores additional trades for consideration when developing ReCon designs. The following explores satellite image scheduling techniques to further the efficacy of an Earth observation constellation. The scheduler incorporates agile satellites to add imaging targets outside of the satellite’s nadir field of view. The ability for a satellite to slew to off-nadir targets is incredibly important when leveraging RGTs. Another design trade considered for ReCon is the propulsion system incorporated on the satellites. Performance and cost trades invoked when using electrical propulsion instead of chemical propulsion are presented within the ReCon framework. This work presents recommendations and future considerations to inform future designers. An investigation into the potential use of staged and responsive launch options further explores flexible options. Using alternative launch strategies allows a program to leverage dropping launch costs and adapt to uncertain imagery demand. The use of flexible options for EO satellite constellation design is vital in low Earth orbit as satellite technology improves, and space becomes a more crowded domain.

The aim of this study is to analyse the value chain of the space sector from launching to final data processing including satellite, payload and ground segment. Additionally, it will provide a parametrisation of costs of the Earth Observation (EO) at LEO compared to other more conventional imaging sources.

Remote observations of Earth from space serve an extraordinarily broad range of purposes, resulting in extraordinary demands on those at the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA), and elsewhere who must decide how to execute them. In research, Earth observations promise large volumes of data to a variety of disciplines with differing needs for measurement type, simultaneity, continuity, and long-term instrument stability. Operational needs, such as weather forecasting, add a distinct set of requirements for continual and highly reliable monitoring of global conditions. The Role of Small Satellites in NASA and NOAA Earth Observation Programs confronts these diverse requirements and assesses how they might be met by small satellites. In the past, the preferred architecture for most NASA and NOAA missions was a single large spacecraft platform containing a sophisticated suite of instruments. But the recognition in other areas of space research that cost-effectiveness, flexibility, and robustness may be enhanced by using small spacecraft has raised questions about this philosophy of Earth observation. For example, NASA has already abandoned its original plan for a follow-on series of major platforms in its Earth Observing System. This study finds that small spacecraft can play an important role in Earth observation programs, providing to this field some of the expected benefits that are normally associated with such programs, such as rapid development and lower individual mission cost. It also identifies some of the programmatic and technical challenges associated with a mission composed of small spacecraft, as well as reasons why more traditional, larger platforms might still be preferred. The reasonable conclusion is that a systems-level examination is required to determine the optimum architecture for a given scientific and/or operational objective. The implied new challenge is for NASA and NOAA to find intra- and interagency planning mechanisms that can achieve the most appropriate and cost-effective balance among their various requirements.

.The growth of Earth-observing small satellite constellations requires effective, automated operations management. State-of-the-art techniques must be improved to manage scheduling of observation data collection, data routing through a crosslinked constellation network, and maintenance of limited onboard resources, as well as to enable scaling to hundreds of satellites. This work has four primary contributions. The first is the development of a hierarchical smallsat constellation planning and scheduling system that addresses data routing and resource management. A centralized ground-based algorithm, the Global Planner, manages the whole constellation, while an onboard algorithm, the Local Planner, replans in real-time to handle urgent, unexpected observations. The second contribution is the development of the software infrastructure for simulating the constellation with high fidelity. The third is the analysis of system performance with a set of representative orbit geometries, ground station networks, and communications contexts. The fourth is the demonstration of routing of urgent observation data. The Global Planner algorithm demonstrates execution on larger problem sizes than the state-of-the-art, by quickly executing for both long planning horizons (requiring

With the second edition of Space Mission Analysis and Design, two changes have been introduced in the Space Technology Library. Foremost among these is the intro duction of the Space Technology Series as a part of the Space Technology Library. Dr. Wiley Larson of the US Air Force Academy and University of Colorado, Colorado Springs, will serve as Managing Editor for the Space Technology Series. This series is a cooperative effort of the Department of Defense, National Aeronautics and Space Administration, Department of Energy, and European Space Agency, coor dinated by the US Air Force Academy. The sponsors intend to bring a number of books into the series to improve the literature base in the fundamentals of space technology, beginning with the current volume. Books which are not a part of the Space Technology Series, but which also represent a substantial contribution to the space technology literature, will still be published in the Space Technology Library. As always, we welcome suggestions and contributions from the aerospace com munity.