The potential impact threat posed by Near-Earth Objects demonstrates the need to enhance planetary defence techniques, to ensure preparedness in case a real collision hazard is ever discovered. This thesis focuses on the trajectory and deflection missions design and optimisation targeting the fictitious asteroid 2024 PDC25. The primary objective is to advance the modelling of deflection strategies with lower Technology Readiness Level (TRL) when compared to the kinetic impactor, but still sufficiently high for near-term applications if their development is prioritised. Specifically, this study analyses single and multiple stand-off Nuclear Explosive Devices (NEDs) in a "Carrier" configuration as an impulsive alternative to the kinetic impactor, alongside several low-thrust strategies: Standard and Enhanced Gravity Tractor (GT and EGT), Single Laser Ablation (SLA) and Ion Beam Deflection (SIBD) in hovering configuration, Multiple Laser Ablation (MLA) and Ion Beam Deflection (MIBD) in formation flight with the asteroid. Through the development of a multi-objective optimisation process, the thesis aims to reach the asteroid with a shape-based low-thrust trajectory and, exploiting one of the developed strategies, maximise the deflection, minimise the warning time and mission cost in terms of spacecraft mass, while ensuring a feasible design of its subsystems. The Pareto-optimal solution maximising the deflection is selected and a more refined algorithm is used to find the time-optimal low-thrust trajectory to rendezvous with the asteroid while still ensuring a feasible spacecraft design. Among the proposed deflection campaigns for asteroid 2024 PDC25, MIBD emerges as the most viable strategy, offering an optimal balance between deflection performance and feasibility within realistic technology development timelines and the available warning time. Also MLA shows promising results but remains limited by its low TRL. The gravity tractor alternatives suffer from low performance or excessive complexity. Nuclear deflection offers the highest deflection capability with a single spacecraft, but faces political and legal limitations.
La minaccia di impatto rappresentata dai Near-Earth Objects evidenzia la necessità di rafforzare tecniche di difesa planetaria per garantire una risposta efficace in caso di reale rischio di collisione. Questa tesi si concentra sulla progettazione e ottimizzazione di traiettorie a bassa spinta e missioni di deflessione per il fittizio asteroide 2024 PDC25. L'obiettivo principale è migliorare la modellazione di strategie di deviazione con un Technology Readiness Level (TRL) inferiore rispetto all’impattore cinetico, ma comunque promettenti per applicazioni future se il loro sviluppo venisse favorito. In particolare, questo studio analizza l’uso di uno o più dispositivi a esplosione nucleare trasportati su un unico veicolo spaziale come alternativa impulsiva all'impattore cinetico, oltre a diverse strategie di deviazione a bassa spinta: il Gravity Tractor (GT) standard e la sua variante Enhanced (EGT); Single Laser Ablation (SLA) e Ion Beam Deflection (SIBD) in configurazione di stazionamento, nonché Multiple Laser Ablation (MLA) e Ion Beam Deflection (MIBD) in volo in formazione con l'asteroide. Attraverso un processo di ottimizzazione multi-obiettivo, la tesi sviluppa una traiettoria a bassa spinta shape-based per raggiungere l’asteroide ed utilizzare una delle strategie di deflessione analizzate, con l’obiettivo di massimizzare la deviazione, minimizzando il tempo di preavviso ed il costo della missione in termini di massa del veicolo spaziale, garantendo un suo design fattibile. Tra le soluzioni Pareto-ottimali, viene scelta quella con la massima deviazione, seguita da un’ulteriore ottimizzazione della traiettoria per minimizzare la durata del volo e aumentare il tempo a disposizione per la deflessione. Tra le strategie, MIBD è la più efficace per deviare 2024 PDC25, con il miglior equilibrio tra prestazioni e sviluppo. Anche MLA mostra risultati promettenti, ma il suo basso TRL ne limita l’attuale applicabilità. Le alternative basate sul gravity tractor sono meno efficaci o presentano una complessità elevata. La deflessione mediante dispositivi nucleari è la strategia a veicolo singolo più efficace, ma è soggetta a limitazioni politiche e legali.
Trajectory and deflection missions design and optimisation for asteroid 2024 PDC25
Franzese, Saverio
2023/2024
Abstract
The potential impact threat posed by Near-Earth Objects demonstrates the need to enhance planetary defence techniques, to ensure preparedness in case a real collision hazard is ever discovered. This thesis focuses on the trajectory and deflection missions design and optimisation targeting the fictitious asteroid 2024 PDC25. The primary objective is to advance the modelling of deflection strategies with lower Technology Readiness Level (TRL) when compared to the kinetic impactor, but still sufficiently high for near-term applications if their development is prioritised. Specifically, this study analyses single and multiple stand-off Nuclear Explosive Devices (NEDs) in a "Carrier" configuration as an impulsive alternative to the kinetic impactor, alongside several low-thrust strategies: Standard and Enhanced Gravity Tractor (GT and EGT), Single Laser Ablation (SLA) and Ion Beam Deflection (SIBD) in hovering configuration, Multiple Laser Ablation (MLA) and Ion Beam Deflection (MIBD) in formation flight with the asteroid. Through the development of a multi-objective optimisation process, the thesis aims to reach the asteroid with a shape-based low-thrust trajectory and, exploiting one of the developed strategies, maximise the deflection, minimise the warning time and mission cost in terms of spacecraft mass, while ensuring a feasible design of its subsystems. The Pareto-optimal solution maximising the deflection is selected and a more refined algorithm is used to find the time-optimal low-thrust trajectory to rendezvous with the asteroid while still ensuring a feasible spacecraft design. Among the proposed deflection campaigns for asteroid 2024 PDC25, MIBD emerges as the most viable strategy, offering an optimal balance between deflection performance and feasibility within realistic technology development timelines and the available warning time. Also MLA shows promising results but remains limited by its low TRL. The gravity tractor alternatives suffer from low performance or excessive complexity. Nuclear deflection offers the highest deflection capability with a single spacecraft, but faces political and legal limitations.| File | Dimensione | Formato | |
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2025_04_Franzese_Tesi.pdf
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Descrizione: Testo della tesi
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2025_04_Franzese_Executive_Summary.pdf
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Descrizione: Executive summary della tesi
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1.09 MB | Adobe PDF | Visualizza/Apri |
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https://hdl.handle.net/10589/236454