Javier Stober, M. Regina Apodaca M., and Seamus Lombardo of Space Enabled presented on their work at IEEE Aerospace 2022, held this year in Big Sky, Montana. The international IEEE Aerospace Conference, with AIAA and PHM Society as technical cosponsors, is organized to promote interdisciplinary understanding of aerospace systems, their underlying science and technology, and their applications to government and commercial endeavors.
You can find the work presented by Space Enabled below:
Presented by Seamus Lombardo, including co-authors Steven Israel and Danielle Wood.
Abstract: Coastal flooding and land subsidence threaten the community of Pekalongan City, Indonesia. These environmental phenomena threaten coastal ecosystems, but also cause extensive economic damage and threaten agriculture and aquaculture industries. When addressing these environmental and socioeconomic challenges, local leaders are faced with the needs of multiple stakeholders as well as decisions on where and how to allocate limited resources to flood mitigation techniques (such as mangrove forest planting or human-made techniques such as sea walls). The coastal phenomena affecting Pekalongan City - such as flooding and land subsidence, as well as the effects these phenomena have on socioeconomic factors (such as agriculture, fisheries, and transportation) represent a complex system as defined in the aerospace System Engineering literature and are also challenging to the mental models of human decision-makers. This work employs Systems Architecture analysis to analyze options for how researchers from universities in the United States can help supplement the work of local leaders to improve coastal resilience in Pekalongan City. Systems Architecture Framework is well suited to this complex system and is employed to evaluate the Context (such as intersecting environmental and socioeconomic factors), analyze Stakeholders (which entails a complex network of local and national governments, NGOs, and universities), assess Stakeholder Needs and Objectives (which relate to economic stability, public health, and environmental restoration), and consider potential Functions and Forms (which could make use of the benefits of techniques from the aerospace field such as satellite remote sensing (SRS) data analyses and integrated modeling) to provide decision support for coastal resilience. This effort focuses on addressing the Function of aiding local decision makers in understanding environmental phenomena, related socioeconomic impacts, and potential policy options and technology investments by analyzing potential Forms for decision support. The results of this Systems Architecture analysis conclude that the intersecting sociotechnical factors of the complex system of coastal flooding in Pekalongan City necessitate an integrated modeling framework to support the decision making of local leaders. Researchers in the United States propose to use the Environment-Vulnerability-Decision-Technology (EVDT) integrated modeling framework as a form to address this function. EVDT considers the interactions between the Environment, Societal Impact, Human Decision-Making, and Technology Design to support decision-making. The EVDT framework is being applied to develop an accessible, Decision Support System (DSS) employing additional Forms of integrated modeling and SRS data analyses to support decision makers. The goal of applying EVDT and employing SRS data to develop this DSS is to aid leaders by helping them understand complex relationships between these disparate societal factors, adapt to changes within the community, and address the needs of multiple stakeholders. The EVDT framework is being utilized to develop a DSS that outputs descriptive and predictive models (which utilize inputs of both SRS data and local socioeconomic information). These models allow decision makers to examine historical data and explore the relationships between these interrelated societal factors under different simulated conditions to evaluate potential policies or technological investments. This work describes the System Architecture analysis and how EVDT is a Form well suited to address the Stakeholder Needs, Objectives, and Desired Outcomes resulting from this analysis. This work also provides a description of initial efforts to develop a DSS prototype informed by inputs from the System Architecture analysis and employing EVDT and SRS data analyses.
Presented by Javier Stober and M. Regina Apodaca M., including co-authors Alana Sanchez, Anika Kamath, Gabriel Owens-Flores, Gladys Chepkirui, Dinuri Rupasinghe, and Danielle Wood.
Abstract: The Space Enabled Research Group at MIT is conducting a multiyear research effort to better understand the technical and logistical challenges posed by the implementation of a wax-based hybrid chemical in-space propulsion system. Paraffin and beeswax are being considered as candidate fuels. The overarching effort includes imagery analysis conducted on paraffin and beeswax centrifugal casting tests on progressively higher-fidelity experimental platforms within transparent hardware which aids in optical investigations. Such platforms include a laboratory optical table and vacuum chamber, a parabolic trajectory microgravity aircraft (three flights to date), the Blue Origin New Shepard suborbital launch vehicle (two flights scheduled for 2021/2022), and the Destiny laboratory module of the International Space Station (ISS; launch scheduled for December 2021).
Each of these platforms allows for testing in a new environment or longer-duration microgravity. The parabolic aircraft flights allow 20 parabolas of 20 seconds, the New Shepard flight 3 minutes, and the ISS flight one month of continuous microgravity time for testing. Atmospheric vs. vacuum experiments allow for isolation of convective and radiative effects on cooling and solidification of the wax, while 1g vs. microgravity experiments allow for evaluation of the role of buoyancy in the convective cooling process.
In order to determine the response of the liquid wax within the centrifugal casting chamber, an image analysis script was made to track the leading edge of solidification for both beeswax and paraffin wax. This script is able to track the solidification process in any environment, both in the lab and in microgravity, as long as there is video available that displays the solidification over time. Determination of expected solidification time is especially important in situations with tighter temporal constraints, such as choosing the optimal material to use for casting on a microgravity flight with less than 20-180 seconds of continuous reduced gravity.The imagery analysis of the experiments aids in understanding the solidification rate dependence upon rotation rate as well as environmental factors. Solidification rate may impact material properties or mission timing.
In addition to experimental work related to casting, a chemical equilibrium solver is used to compare predicted performance of paraffin, beeswax, and hydroxyl-terminated polybutadiene (HTPB) hybrid rocket fuels under identical conditions which warrants continued study of beeswax as a candidate green hybrid rocket fuel. These results indicate that beeswax, paraffin, and HTPB exhibit very similar performance which corroborates that the renewability and cost advantages of beeswax warrant its further study as a high-performing hybrid rocket fuel.