Case Study
Flexible Deployment of Active Debris Removal Spacecraft
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Key Idea Description
Performance Optimization in Active Debris Removal (ADR) through flexible deployment strategies. This study explores the use of real options analysis to design ADR systems that can adapt to budget uncertainties and varying debris removal rates. By incorporating flexible options such as additional spacecraft launches and payload assistance from cubesats, the study aims to enhance the effectiveness and efficiency of debris removal operations, ultimately increasing the removal of lethal non-trackable debris fragments.
- Broad Area: Space Debris Management, Satellite Operations, Space Systems Engineering, Active Debris Removal, Strategic Flexibility.
- Main issues of case: The study addresses challenges such as budget allocation uncertainties, the effectiveness of capture technologies, and the need for international cooperation in large-scale debris removal efforts.
- Main analytic topics: Utilizes real options analysis and Monte Carlo simulations to evaluate the economic and operational impacts of flexible deployment strategies, comparing various scenarios to optimize fragment removal and minimize program risks.
Insights
- Flexibility Enhances Debris Removal: Incorporating flexible deployment strategies, such as adding more spacecraft and cubesats, increases debris removal efficiency by up to 66% and 13%, respectively.
- Cost-Effective Adaptation: The study shows that strategic flexibility in ADR systems leads to significant cost savings and performance gains, optimizing the removal of lethal debris fragments with an efficient budget allocation.
Training
Relevant lectures:
- Paradigm change in engineering systems and planning
- How to optimise design and decision-making under uncertainty
- How to manage the design process
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Abstract
Flexible options are integrated into the ADR design to mitigate losses and increase performance from these uncertainties. An option to build and launch additional debris removal spacecraft exploits upside opportunities from budget uncertainty and increases baseline fragment removal by 66%. A payload flexibility option is added to counter the uncertainty of removal rate by designing and launching cubesats that assist ADR spacecraft and increase probability of debris capture success. This increases fragment removal by 13%.
The final recommended system design uses both flexible options. This design adds an average of 1 spacecraft every 2 years and implements the cubesat option later in the system cycle to reduce costs. This results in a balanced combination of important performance metrics with an average of 1438 lethal fragments removed and $2.80B spent. Other design alternatives are also presented that optimize specific metrics.
Summary
Introduction:
The report addresses the growing concern of orbital debris, which threatens the safety of active satellites. The study focuses on Active Debris Removal (ADR) systems designed to mitigate the risks posed by large derelict debris objects. These objects can collide and create smaller, untrackable fragments that are lethal to spacecraft.
Problem and Motivation:
The accumulation of orbital debris, primarily from past satellite collisions and anti-satellite missile tests, has created a significant threat to active spacecraft. With over 1,000,000 debris fragments estimated to exist, preventing the creation of Lethal Nontrackable Debris (LNT) is crucial. ADR systems aim to remove large debris objects, reducing the risk of collisions and subsequent creation of LNT.
System Model:
The ADR mission model operates as follows:
- Launch ADR spacecraft to orbit and rendezvous with debris targets.
- Capture and deorbit debris, allowing it to decay in Earth’s atmosphere.
- Continue the cycle with subsequent targets.
Key Decisions:
- Number of ADR spacecraft to deploy.
- Type of capture technology used.
- Target regions in Low Earth Orbit (LEO) for debris removal.
Performance Metrics:
- Fragment Reduction: The primary metric, aiming to minimize debris fragments.
- Program Risk: Evaluated based on the probability of capture success and budget adherence.
- Net Present Value (NPV) of Spending: Calculated to assess financial feasibility.
Base Case:
- Deterministic Case: With 2 spacecraft, the baseline scenario estimates the removal of 793 fragments, a program risk score of 1 out of 5, and total spending of $2.38 billion.
- Uncertainty Case: Introducing budget variability (+/- 22%) and removal rate uncertainty (+/- 30%) results in an average removal of 745 fragments and spending of $2.39 billion. Program risk increases due to potential budget overruns.
Flexible Designs:
To mitigate uncertainties and exploit opportunities, two flexible options are proposed:
- Add Spacecraft: Build and launch additional ADR spacecraft if budget conditions allow.
- Helper Cubesats: Deploy small cubesats to assist in debris capture, increasing capture success probability from 60% to 95%.
Comparison and Recommendation:
The recommended design integrates both flexible options, balancing performance metrics with cost. This approach results in an average removal of 1,438 fragments and spending of $2.80 billion, offering the best performance for a relatively modest increase in spending.
Conclusion
Implementing a flexible ADR system design significantly enhances debris removal performance while managing uncertainties in budget and removal rates. This approach ensures a balanced combination of high fragment reduction and financial sustainability, making it a practical solution for multinational debris removal efforts.