Ph.D. Proposal 

Victor Yang

(Advisor: Prof. Dimitri Mavris)

A Design Methodology for Resilient Cislunar Space Domain Awareness Architectures

Monday, December 9
2:00 p.m. EST
CoVE – Weber SSTII
Teams Meeting Link: Join the meeting now

Abstract:
Cislunar space is the next frontier of human space exploration in the coming decades. The push for scientific and commercial missions by national space agencies and private entities alike is driving the resurgence of the race to the Moon. With the goal of long-term sustained human presence in the cislunar regime, critical space infrastructure to support human activity has been studied in recent years. Space domain awareness (SDA) is one such infrastructure that tackles the detection, tracking, and identification of space objects. SDA for near-Earth applications has been crucial for debris avoidance, space traffic management, and tracking of adversary space assets. As activity in the cislunar regime grows, the need for SDA to ensure a safe and secure operational environment will naturally follow. As a critical space infrastructure, SDA is the backbone of cislunar activity, in which its disruption may cause significant losses. The concepts of systems resiliency derived from terrestrial infrastructure and space mission success form the motivation for resilient space domain awareness. Other space missions benefit from the information provided by SDA, and thus resilient cislunar SDA fundamentally improves the operational environment for all future cislunar missions.

The design process of space systems traditionally conducts disruption and recovery resilience analysis after the conceptual design phase, which prioritizes high-level performance evaluation and costing. Applying resilience analysis upon optimal solutions from the initial optimization procedure yields a more restricted solution space to explore and less traceability between the resilience of solutions and the design space. As such, options to improve architectural resilience are limited by the additional burden of design and modeling complexity. The proposed methodology seeks to incorporate resilience into the conceptual design phase through a phase-based performance framework that captures space domain challenges and priorities, is flexible to emerging disruption events and technologies, and enables rapid evaluation of a resilience metric.

The resilience framework requirements lead to three research gaps and questions. Existing space systems resilience frameworks are unable to execute the design process for cislunar SDA due to poor resilience definition scoping and modeling challenges. Current cislunar space domain awareness studies prioritize dynamics and sensing problems, which do not capture the most vulnerable segment of space systems: communications. The proposed framework thus needs delay-tolerant network (DTN) communications modeling to better encapsulate the scope of domain awareness and emerging threats in the cislunar domain. Mixed-temporal graph models have been identified as an alternative modeling solution to constellation design where performance evaluation occurs outside the agent-based model, where global efficiency or information latency metrics can be applied to evaluation DTN performance.

Current resilient spacecraft constellation literature focus on narrow disruption types or phases, namely the robustness phase, which is treated as resilience in many works. Robustness evaluation is typically accomplished through Monte Carlo simulations of disruptions, which limits the design space size and disruption types to be captured. Following the previous research question, graph models have been demonstrated in literature as efficient means of robustness evaluation. Graph metrics based on centrality, entropy, and spectral methods have been proposed and are promising to capture disconnection and transmission speed robustness in a network. The mixed-temporal graph formulation of cislunar SDA constellation is thus expected to enable rapid evaluation of communications performance and robustness to acceptable accuracy.

To apply the resilience framework beyond the robustness phase, significant modeling efforts are typically required to capture the effects of resilience enhancing technology and infrastructure solutions upon resilience and cost. To demonstrate the utility of the resilience metric, the avoidance and recovery phase will be modeled based on cost and performance functions. Through a decomposition of resilience to its phases and specific technical capabilities, a traceable mapping between resilience technology selections and resilience can be accomplished. A resilience metric based on the mapping will be compared to Monte Carlo simulations that capture all phases to determine the accuracy of the proposed approach.

The proposed resilience framework will be applied in a demonstration of the cislunar SDA conceptual design process to validate the methodology. Resilience will be treated as an objective in the multi-objective optimization process, in which trade-space analysis with sensing performance, communications performance, and cost can be accomplished. The expected outcome of the experimentation and demonstration is a cislunar space domain awareness design methodology that yields more traceable and resilient design alternatives, such that stakeholders will better understand orbit utilization and resilience solution options.

Committee:

• Prof. Dimitri Mavris – School of Aerospace Engineering (advisor)
• Prof. Kyriakos Vamvoudakis – School of Aerospace Engineering
• Prof. Brian Gunter – School of Aerospace Engineering
• Dr. Michael Balchanos – School of Aerospace Engineering
• Dr. Michael Steffens – Draper Laboratory