### Abstract

The paper demonstrates the technical feasibility to deflect a 100 m diameter asteroid using a moderate size spacecraft carrying a 1-20 kW solar-powered class laser. To this purpose, a recent model of the laser ablation mechanism based on the characteristics of both the laser systems and the asteroid has been used to calculate the exerted thrust in terms of direction and magnitude. This paper shows a preliminary deflection uncertainty analysis for two different control logic and assuming different laser mechanism capabilities. In particular, an optimal thrust control direction and fixed laser pointing strategies were considered with two laser optics settings: the first maintaining the focus length fixed and the second able to exactly focus on the surface. Preliminary results show that in general the fixed laser pointing strategy at low power is less able to impart high deflection. Nonetheless, when the power increases, the optimal thrust method produces undesired torques, which reduces the laser momentum coupling as side effects. However, the overall efficiency is higher in the optimal thrust case. Since the collision risk between an impacting asteroid and the Earth depends on the probability distribution of the input uncertainty parameters, it is necessary to study how the overall deflection will be affected. Both aleatory and epistemic uncertainties are taken into account to evaluate the probability of success of the proposed deflection methods.

Language | English |
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Title of host publication | Aerospace Conference, 2016 IEEE |

Place of Publication | Piscataway |

Publisher | IEEE |

Number of pages | 13 |

ISBN (Print) | 9781467376761 |

DOIs | |

Publication status | Published - 27 Jun 2016 |

Event | 2016 IEEE Aerospace Conference, AERO 2016 - Big Sky, United States Duration: 5 Mar 2016 → 12 Mar 2016 |

### Conference

Conference | 2016 IEEE Aerospace Conference, AERO 2016 |
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Country | United States |

City | Big Sky |

Period | 5/03/16 → 12/03/16 |

### Fingerprint

### Keywords

- laser modes
- laser ablation
- laser beams
- power lasers
- space vehicles
- torque
- asteroids
- astronomical techniques
- celestial mechanics
- optimal control
- statistical distributions

### Cite this

*Aerospace Conference, 2016 IEEE*[7500677] Piscataway: IEEE. https://doi.org/10.1109/AERO.2016.7500677

}

*Aerospace Conference, 2016 IEEE.*, 7500677, IEEE, Piscataway, 2016 IEEE Aerospace Conference, AERO 2016, Big Sky, United States, 5/03/16. https://doi.org/10.1109/AERO.2016.7500677

**Optimal control of a space-borne laser system for a 100 m asteroid deflection under uncertainties.** / Vetrisano, Massimo; Cano, Juan L.; Thiry, Nicolas; Tardioli, Chiara; Vasile, Massimiliano.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution book

TY - GEN

T1 - Optimal control of a space-borne laser system for a 100 m asteroid deflection under uncertainties

AU - Vetrisano, Massimo

AU - Cano, Juan L.

AU - Thiry, Nicolas

AU - Tardioli, Chiara

AU - Vasile, Massimiliano

N1 - (c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.

PY - 2016/6/27

Y1 - 2016/6/27

N2 - The paper demonstrates the technical feasibility to deflect a 100 m diameter asteroid using a moderate size spacecraft carrying a 1-20 kW solar-powered class laser. To this purpose, a recent model of the laser ablation mechanism based on the characteristics of both the laser systems and the asteroid has been used to calculate the exerted thrust in terms of direction and magnitude. This paper shows a preliminary deflection uncertainty analysis for two different control logic and assuming different laser mechanism capabilities. In particular, an optimal thrust control direction and fixed laser pointing strategies were considered with two laser optics settings: the first maintaining the focus length fixed and the second able to exactly focus on the surface. Preliminary results show that in general the fixed laser pointing strategy at low power is less able to impart high deflection. Nonetheless, when the power increases, the optimal thrust method produces undesired torques, which reduces the laser momentum coupling as side effects. However, the overall efficiency is higher in the optimal thrust case. Since the collision risk between an impacting asteroid and the Earth depends on the probability distribution of the input uncertainty parameters, it is necessary to study how the overall deflection will be affected. Both aleatory and epistemic uncertainties are taken into account to evaluate the probability of success of the proposed deflection methods.

AB - The paper demonstrates the technical feasibility to deflect a 100 m diameter asteroid using a moderate size spacecraft carrying a 1-20 kW solar-powered class laser. To this purpose, a recent model of the laser ablation mechanism based on the characteristics of both the laser systems and the asteroid has been used to calculate the exerted thrust in terms of direction and magnitude. This paper shows a preliminary deflection uncertainty analysis for two different control logic and assuming different laser mechanism capabilities. In particular, an optimal thrust control direction and fixed laser pointing strategies were considered with two laser optics settings: the first maintaining the focus length fixed and the second able to exactly focus on the surface. Preliminary results show that in general the fixed laser pointing strategy at low power is less able to impart high deflection. Nonetheless, when the power increases, the optimal thrust method produces undesired torques, which reduces the laser momentum coupling as side effects. However, the overall efficiency is higher in the optimal thrust case. Since the collision risk between an impacting asteroid and the Earth depends on the probability distribution of the input uncertainty parameters, it is necessary to study how the overall deflection will be affected. Both aleatory and epistemic uncertainties are taken into account to evaluate the probability of success of the proposed deflection methods.

KW - laser modes

KW - laser ablation

KW - laser beams

KW - power lasers

KW - space vehicles

KW - torque

KW - asteroids

KW - astronomical techniques

KW - celestial mechanics

KW - optimal control

KW - statistical distributions

UR - http://www.scopus.com/inward/record.url?scp=84978536276&partnerID=8YFLogxK

UR - http://2016.aeroconf.org/

U2 - 10.1109/AERO.2016.7500677

DO - 10.1109/AERO.2016.7500677

M3 - Conference contribution book

SN - 9781467376761

BT - Aerospace Conference, 2016 IEEE

PB - IEEE

CY - Piscataway

ER -