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This paper develops a flexibility management framework for space logistics mission planning under uncertainty through decision rules and multistage stochastic programming. It aims to add built-in f...

This paper performs a human subject study to investigate the effect of an augmented design interface on the communication behavior and performance of multidisciplinary design teams. We frame an aircraft design task as an iterative multidisciplinary design process with 12 design parameters shared across four design actors, each in charge of one discipline, implemented in a browser-based virtual design studio. We conduct a baseline experiment to collect observational data on design communication and performance and recommend two augmentations to improve team performance: a flexible design timer to control design iterations and a history catalog that quantifies the quality of previous design states. Results of an augmented experiment show the new features increase design iteration rate and decrease chat message rate, enabling the most successful teams to complete the task faster. We discuss the implications of our results in the broader context of digitalization and transformations due to information systems.

This paper evaluates a questionnaire-based risk attitude assessment method to quantify individual risk attitudes for strategic, multi-actor design decisions. A lottery-equivalence questionnaire elicits a utility curve for risky payoffs which is fit to a Constant Absolute Risk Aversion (CARA) model. Secondary data from a multi-actor design experiment provides observations of strategic decisions in two-actor design games for validation. 124 participants complete the risk attitude questionnaire and a series of 29 experimental tasks. Assuming participants follow the risk dominance equilibrium selection criterion, a risk-neutral utility function accurately predicts 62.2% of decisions. Incorporating risk attitudes elicited from the questionnaire only increases the accuracy to 63.3% while incorporating risk attitudes inferred from observations increases the accuracy to 77.5%. While participants exhibit differential risk attitudes in design tasks, results show the lottery-equivalent questionnaire does not provide risk attitudes consistent with strategic design decisions. Results support findings that risk in the engineering domain is contextual. This paper concludes that risk attitude is an important factor in understanding strategic decisions in interactive engineering design settings and understanding risk attitudes can help create more efficient design processes.

Internet satellite constellations are expected to play an important role in accommodating the rising global demand for internet access. Such rise in demand, however, is highly uncertain. Staged deployment is an approach that provides flexibility to tackle demand uncertainty by enabling the real option to reconfigure a constellation if demand changes. Advancements in satellite technology have led to the emergence of multi-layered constellations. This opens the opportunity to enhance staged deployment by enabling an additional real option: adding a new layer to a constellation. This real option has no associated reconfiguration costs, and therefore has the potential to reduce the cost of staged systems deployment. This paper proposes a framework to design multi-layer staged deployment systems and analyse their effectiveness in modern mega-constellations under global demand uncertainty. The framework is applied to four case studies based on market projections. Results show that multi-layer staged deployment decreases the expected life-cycle cost (ELCC) by 42.8% compared to optimal traditional single-layer deployment. Multi-layer staged deployment is more cost effective than single-layer staged deployment in all practical cases, which decreases ELCC by 22.9% compared to traditional deployment. Several cost altering mechanisms in staged deployment are identified. The results and analysis provide improved economic performance and better resource utilization, thus contributing in the long term to improved sustainability and market resilience. An accompanying decision support system provides system engineers with valuable insights on how to reduce deployment costs using the proposed multi-layered staged strategy.

This paper studies and develops multiple auction-based algorithms for resource exchange among decentralized systems in federated networks with distributed computational resources. Decentralized resource owners and users use processing, storage, and communication units to perform the available computational tasks at each time step while an auctioneer facilitates allocating resources. The auctioneer communicates with federates and receives bids for buying and selling resources, solves combinatorial problems, and proposes prices to federates. Multiple auction-based mechanisms are formulated and assessed using collective performance metrics in a networked federation. The auction-based algorithms include four reverse-bid and double-sided auctions: (1) first-price auction, (2) sequential non-linear pricing auction, (3) min–max closed-form pricing auction, and (4) balanced and maximizing closed-form pricing auction. For results, we assess algorithms for economic and computational efficiency using extensive simulation runs in hundreds of network topologies and initial conditions. The metrics introduced for our numerical validation include normalized bids and prices, collective values, and convergence rates.

Historically constellations of communication satellites were designed to function optimally for a specific expected global demand. This estimation is based on assumptions of the number of users and the average activity per user, both of which are highly uncertain. This uncertainty can cause deployed constellations having a capacity far lower than demand, lowering performance and creating opportunity cost, or far higher than demand, potentially bankrupting the company that owns the system as income cannot recoup the initial investment. An approach has previously been proposed wherein a satellite constellation is deployed in stages with each stage increasing the capacity of the constellation through reconfiguration of on-orbit satellites and launch of new satellites. This method has been previously demonstrated to significantly reduce the lifecycle cost of low-earth orbit communication satellite constellations. Recent proposals for satellite constellations to support global broadband internet providers have introduced new technologies as well as new methods of constellation design resulting in far larger constellations than previously envisioned (mega-constellations). Renewed interest and investment in the development global broadband networks demand a return to this topic to investigate its impact in this space.

NASA’s New Observing Strategies (NOS) thrust provides a framework for identifying technology advances needed to exploit newly available observational capabilities, including high-quality instruments on constellations of SmallSats and CubeSats, that enable measurement of phenomena that could not be studied using previously available techniques. Satellite developers and operators require software tools to simulate new technologies and validate new mission concepts that can incorporate a dynamic set of observing assets with various instruments located at different vantage points. These new mission concepts include many more design variables than traditional missions, requiring tools to facilitate trade analysis and concept validation in an iterative fashion, similar to an Observing System Simulation Experiment (OSSE) framework. Several recent projects address design and operational trades by designing software packages such as the Trade-space Analysis Tools for Constellations (TAT-C) co-developed by Stevens Institute of Technology, the Simulation Toolset for Adaptive Remote Sensing (STARS) developed by The Ohio State University, and the Virtual Constellation Engine (VCE) developed by the University of Southern California. Each tool has different but complementary capabilities and can be run independently. However, linking capabilities using modern web-based service application programming interfaces (APIs) contributes to a powerful modeling ecosystem for the Earth Science community with well-defined interfaces that facilitate interoperability with existing mission planning tools. This presentation will describe the capabilities of each individual software tool as well as recent efforts to integrate their capabilities to evaluate and mature constellation mission concepts as part of the NOS thrust.

The New Observing Strategies Testbed prototypes and evaluates new information systems technology for distributed space missions. This paper discusses the rationale and design of an event-driven architecture to integrate and orchestrate component system models. An example application case based on the FireSat mission describes environment, spacecraft, ground station, and adjudication applications orchestrated by a testbed manager. Test run results quantify key performance measures like the latency between fire ignition and detection to evaluate observing system strategies.

Global Navigation Satellite System Radio Occultation (GNSS-RO) is a technique that relies on the change of a signal transmitted from a Global Navigation Satellite System (GNSS) as it passes through the planet’s atmosphere. This technique is not only suitable to study weather forecasting or climate change, but also offers a low-cost application. This report aims to characterize and parametrize the system architecture of commercial companies pursuing the Commercial Weather Data Pilot (CWDP) contract by the National Oceanic and Atmospheric Administration (NOAA). The approach of the paper will start by explaining the Radio Occultation technique and its potential application to Numerical Weather Prediction (NWP). The paper then identifies the main stakeholders of radio occultation and NWP, and their needs. Some key functional requirements are pinpointed, and the challenges that some of these architectures must overcome is discussed.

This paper introduces a mechanism for pricing and exchanging resources in federated networks of task-processing elements. An operational model is developed to allocate processing, storage and communication resources to computational demands. This model finds an efficient and stable solution to combinatorial routing and allocating resources among networked elements with technical constraints. Using mixed-integer linear programming (MILP) formulation, we find optimal solution to processing tasks, allocating links, storing and delivering data to destination. A trusted auctioneer uses a mechanism to allocate resources to computational tasks and suggests prices for exchanging resources across a federation using minimum number of MILP solutions to a network topology. The proposed mechanism maximizes the collective value for a federation and ensures an expected value for each federate and minimizes the computational cost associated with the operational runs. The auctioneer doesn’t have access to utility functions and private information on resources a priori while assumes a federation with self-centric and rational participants. An application of federated satellite systems is developed with endogenous components such as adaptive bidding and opportunity cost of using resources. Numerical results show that the proposed mechanism improves the collective and expected values in a federation with strategic federates.