Annalisa L. Weigel

Assessing the Flexibility Provided by Fractionated Spacecraft

This paper introduces the concept of spacecraft fractionation, which transforms a traditional monolithic spacecraft into a network of elements where a free-flying payload module is supported by nearby free-flying infrastructure modules supplying communications, data handling, power, etc. Models were developed from a customercentric perspective to assess different fractionated spacecraft architectures relative to traditional spacecraft architectures using multi-attribute analysis. Along with traditional attributes of mass and cost, non-traditional attributes of maintainability, scalability, flexibility, and responsiveness were included in the assessment. A framework was created to clearly define and evaluate these non-traditional attributes, and appropriate metrics were constructed. This study demonstrates that if those non-traditional attributes are valued enough, customers would choose fractionated spacecraft rather than traditional ones. I. Introduction Traditional spacecraft are designed for one-time use. They are typically monolithic and have a tailored design. Because of the long development and manufacturing times, designers tend to increase the lifetime of traditional spacecraft and as a result spacecraft tend to grow larger and more complex. This tendency creates large costs and risks associated with a single mission and prevents use of most advanced technologies and reuse of launched elements. Moreover, these traditional architectures have a major drawback in that they limit the possible adaptations of spacecraft to the likely changes in their requirements or environment during their life cycle. The use of modular and standard components was a first step to reduce costs, risks, and development, manufacturing, and testing times. Reconfigurable spacecraft are now being developed to improve flexibility and decrease time constraints. Such new systems are based on standard modules that would be docked and undocked depending on the requirements. Taking modularity a step further means considering a spacecraft made of several smaller building blocks instead of a monolithic one. The technologies recently developed for distributed and cooperative space systems made conceivable this idea of fractionating spacecraft. The concept of fractionated spacecraft transforms a traditional monolithic spacecraft into a network of elements: a free-flying payload is supported by free-flying modules forming an on-orbit infrastructure. Those modules can be reconfigured, added, or exchanged independently from the others, and be reused over several missions. The lifetime of space assets would be extended by building those reusable and smaller components, which would be a first step toward sustainable space utilization.

Measuring the Value of Designing for Uncertain Future Downward Budget Instabilities

A method is presented for understanding the behavior of space system program costs under downward annual budget pressure, with a real options analysis incorporated for determining the maximum worth of an architecture transition option to hedge against program budget uncertainty. The relationship between program schedule extension and resulting program cost growth is examined. As downward pressure is applied to a program’s yearly budget, its overall length and, hence, cost increase. It is found that sets of candidate space system architectures fo ra given program can be in one of three stages of behavior in response to downward annual budget pressure, and expressions are derived indicating stage transition points. Each of these three stages of behavior indicates a different level of space system architecture robustness to annual budget levels and implies different recommended actions for a system designer or program manager. For the middle stage of behavior, maintaining an option to transition to a lower cost architecture would be one way of achieving robustness under downward budget pressure. Then real options are examined as a valuation method for understanding the maximum value that might be placed on the ability to switch to a lower cost architecture.

Assessing Fractionated Spacecraft Value Propositions for Earth Imaging Space Missions

Fractionated spacecraft consist of physically independent, “free-flying”modules composed of various subsystems. Thus, a fractionated spacecraft might consist of one module providing power generation and storage, another module providing communications, another module providing the payload functions, and so on. Fractionated spacecraft are of particular interest for earth imaging missions because of their ability to physically decouple pointing-intensive payloads from subsystems not requiring such strict pointing. This in turnmay enable fractionated spacecraft to have a lower life cycle cost and longer mission lifetime relative to a comparable monolithic spacecraft, for a given performance level. In this research, fractionated architectures were assessed using a custom-built spacecraft model, and their respective life cycle costs were quantified using a stochastic life cycle simulation and parametricmodel. Results demonstrate that, relative to a comparablemonolithic spacecraft, fractionated spacecraft can have a stronger value proposition through the attainment of a lesser life cycle cost for an equal if not longer mission lifetime than comparable monoliths, for high-resolution earth imaging missions.

The Structural Approach to Shared Knowledge An Application to Engineering Design Teams

Objective: We propose a methodology for analyzing shared knowledge in engineering design teams. Background: Whereas prior work has focused on shared knowledge in small teams at a specific point in time, the model presented here is both scalable and dynamic. Method: By quantifying team members’ common views of design drivers, we build a network of shared mental models to reveal the structure of shared knowledge at a snapshot in time. Based on a structural comparison of networks at different points in time, a metric of change in shared knowledge is computed. Results: Analysis of survey data from 12 conceptual space mission design sessions reveals a correlation between change in shared knowledge and each of several system attributes, including system development time, system mass, and technological maturity. Conclusion: From these results, we conclude that an early period of learning and consensus building could be beneficial to the design of engineered systems. Application: Although we do not examine team performance directly, we demonstrate that shared knowledge is related to the technical design and thus provide a foundation for improving design products by incorporating the knowledge and thoughts of the engineering design team into the process.

Evaluating the Cost and Risk Impacts of Launch Choices

A method is presented for quantitatively assessing the generalized cost and risk impacts to a space system architecture of a restrictive government launch policy and application is made to the case of the U.S. space transportation policy of 1994. For both a restrictive and unrestrictive launch policy scenario, a mixed integer optimization algorithm is used to select the best launch vehicle suite for a given satellite system architecture based on the cost or risk selection rule for a particular type of decision maker. The cost and risk impacts that result in the two scenarios are compared over an extensive matrix of satellite masses, altitudes, inclinations, and constellation arrangements. Generalized launch policy cost impact estimating relationships are derived, and risk impacts are represented by descriptive statistics. The analysis finds that the 1994 U.S. launch policy affects the launch cost and launch risk of many types of satellite system architectures.

Interaction of policy choices and technical requirements for a space transportation infrastructure

Abstract This paper first presents a framework and analysis methodology for understanding the environment in which political aspects and technical aspects of politico-technical space system design interact, as well as how impacts flow from the political domain to the technical domain in this environment. Next, a space transportation infrastructure is presented, describing its elements, objectives and relevant policy directions. Then the space transportation infrastructure is analyzed according to the framework, and important insights are discussed.

Dynamics of Air Transportation System Transition and Implications for ADS-B Equipage

The U.S. Air Transportation Systems faces substantial challenges in transforming to meet future demand. These challenges need to be understood and addressed in order to successfully meet future system needs. This paper uses a feedback model to describe the general system transition process and identify key issues in the dynamics of system transition, with particular emphasis on stakeholder cost-benefit dynamics and safety approval processes. Finally, in addition to identifying dynamics and barriers to change the paper proposes methods for enabling transition through the use of levers such as incentives, mandates, and infrastructure development. The implementation of ADS-B is studied as a pathfinding technology for planned Air Transportation System changes. The paper states that overcoming stakeholder barriers and ensuring efficient safety approval and certification process are the key enablers to the successful implementation of ADS-B.

A Framework to Encourage Successful Technology Transition in Civil Aviation

Technology transitions are essential to transforming air traffic management to meet future capacity needs. Encouraging and obtaining equipage adoption is one crucial aspect of technology transitions. We propose an approach for developing appropriate strategies to persuade aviation stakeholders to transition to new technologies. Our approach uses cost, benefit, and value distribution across stakeholders and over time to determine which strategies are most appropriate to persuading aircraft operators to adopt new equipage. Equipage that may show an overall positive value can nevertheless fail to provide value to individual stakeholders. Such imbalances in value distribution between stakeholders or over time may lead to stakeholder intransigence and can stymie efforts to transform air traffic management systems. Leverage strategies that correct these imbalances and accelerate the realization of value for all stakeholders can enhance cooperation and increase the likelihood of a successful transition to the new technology

Implications of DoD Acquisition Policy for Innovation: The Case of Operationally Responsive Space

This paper uses an innovation theory lens to assess the potential for operationally responsive space to increase the ability of government space acquisition to meet the emerging needs of Joint Combatant Commanders. Two core challenges of generating innovation in national security space are identified: 1) enabling bottom-up initiative in a monopsony market structure; and 2) fostering an entrepreneurial environment for both component and system level concept development within an increasingly risk-averse system. The current military acquisition system addresses these challenges through a two-tiered process which separates technology development from project-based acquisition. However, this method of separation is not a complete solution as: 1) it fails to value the importance of architectural innovation; 2) it creates a disaggregated knowledge base which exacerbates the difficulty of top-down specification and bottom-up integration; and 3) fails to generate an entrepreneurial supply-side spirit. The operationally responsive space paradigm has the potential to resolve parts of this issue by generating a more dynamic acquisition environment; however, it remains to be seen whether the required significant philosophical change can be achieved in practice.

International Collaboration on Satellite-Enabled Projects in Developing Countries

There is great potential for satellite technology to meet needs in developing countries. This study investigates ninety case studies of satellite‐enabled activities in Africa. The activities all involve at least one of the following three satellite technologies: communication, remote sensing or navigation. A review of the case studies suggests that the majority of the satellite‐enabled activity in Africa is the result of collaboration or contracting between African and external partners. Such collaboration often involves technology transfer to Africa. The case studies are analyzed along several parameters, including technical achievement and the source of funding, expertise or initiative. These parameters show the extent and source of technology transfer within the project. Several projects are highlighted to provide concrete examples. The observations from this study lead to recommendations for the structuring of future technology transfer programs that aim to help developing countries use satellite tech...