Identification and evolution of quantities of interest for a stochastic process view of complex space system development

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 115-116).The objective of stochastic process design is to strategically identify, measure, and reduce sources of uncertainty to guide the development of complex systems. Fundamental to this design approach is the idea that system development is driven by measurable characteristics called quantities of interest. These quantities of interest collectively describe the state of system development and evolve as the system matures. This thesis provides context for the contributions of quantities of interest to a stochastic process view of complex system development using three space hardware development projects. The CASTOR satellite provides the opportunity for retrospective identification of quantities of interest and their evolution through time. As a complement to CASTOR, the preliminary design of the REXIS x-ray spectrometer provides the foundation for applying stochastic process approaches during the early phases of system development. Lastly, a spacecraft panel structural dynamics experiment is presented that illustrates analysis techniques commonly employed in stochastic process analysis.by George Ralph Sondecker, IV.S.M

Value-Driven Analysis of New Paradigms in Space Architectures: An Ilities-Based Approach

Current commercial, civil, and military space architecture designs perform exquisitely and reliably. However, today’s architecture paradigms are also characterized by expensive launches, large and expensive high-performance spacecraft, long development cycles, and wide variations in ground architectures. While current assets provide high-quality services, and future assets are slated to improve performance within the same design frameworks, proposed future architectures may not be capitalizing on technology improvements, system innovations, or policy alternatives explored during the last two decades. This paper identifies five “trends” along which space architectures may develop, aimed at granting systems several “ilities,” such as resiliency, robustness, flexibility, scalability, and affordability. The trends examined include: commercialization of space, significant reductions in launch costs and the development of hybrid or reusable launch systems, development of on-orbit infrastructure and servicing, aggregation or disaggregation of orbital assets, and the automation and standardization of ground architectures. Further refinement of these key technological and system trends could result in major paradigm shifts in the development and fielding of space operations as well as lead to space architecture designs in the future that are radically different from those today. Within the framework of systems engineering ilities and risk management, this paper reviews current literature surrounding these new change trends and justifies their potential to cause significant paradigm shifts. By examining the work and research conducted so far through an ilities-based approach, systems engineers can more fully appreciate the value being offered by these trends

SENSE: The USAF SMC/XR NanoSatellite Program for Space Environmental Monitoring

The Development Planning Directorate at the Air Force Space and Missile Systems Center (SMC/XR) is assessing the utility of NanoSatellites for performing operational space weather missions. The directorate is leading a demonstration called the Space Environmental NanoSatellite Experiment (SENSE) that will enhance the field of Space Environmental Monitoring (SEM) and provide data to populate the Global Assimilation of Ionospheric Measurements (GAIM) model. Scheduled for launch in 2013, the SENSE architecture consists of two 3U CubeSats and supporting ground segment. The space vehicles carry a combined suite of three SEM payloads designed to characterize total electron content (TEC) and ionospheric scintillation, ion and neutral winds composition, and ionospheric UV nightglow. This paper outlines how the SENSE CubeSat mission contributes to enhanced global awareness for the warfighter and space weather community