1. Demonstration for cm-size space debris REDUCTION/REMEDIATION from the International Space Station Toshikazu Ebisuzaki, S. Wada, L.W. Pitrowski, M. Casolino (RIKEN), R. Soulard, M. N. Quinn, G. Mourou (IZEST, Ecole Polytechnique, France)

2. Concept of our technical demonstrator of the laser removal EUSO – Detection – Position and velocity Crude determination CAN laser system – Search beam – Position and velocity Fine determination – Shooting Operation

3. Reentry by reaction force of laser ablation

4. Laser Shooting Operation

5. Reaction Force by Laser Abration

6. Ground vs. Space Good – Higher power – larger optics – Easy to maintenance – Longer life Bad – Longer distance~1000km – Atmospheric refraction ~arcminuetes~10 -3 rad Turbulence Good – No atmosphere – Closer~100 km Bad – Expensive – Smaller power – Smaller size in optics – Shorter life – No maintenance

7. Three steps of debris removal Target Debris a=0.5-10 cm, d ～ 100 km, ｖ rel ～ 1-15 km

8. 1.EUSO-TA: Ground detector at Telescope Array site: 2013- 2.EUSO-BALLOON: 1st balloon flight from Timmins, Canada (French Space Agency CNES) Aug 2014 3.MINI-EUSO (2017) 4.K-EUSO (2019) 5.JEM-EUSO (>2020+) The EUSO program JEM-EUSO 14 o MINI-EUSO EUSO-TA (2013-)

9. Two Double sided curved Fresnel Lens + Diffractive Optics

10. Tool radiusR0.5mm Work speed50rpm Feed Speed0.2mm/min Depth of cut0.005mm/pass Work piecePMMA cutting concave surface EUSO Technology 1 ： Manufacturing Large lens (up to 3m) Cutting condition

11. 11 EUSO Technology 2 Photo-detector Hamamatsu R11265-03- M64 64 pixel MAPMT

12. Detection Limit: Reflection of sunlight D=25 cm D=2.5 m

13. CAN (Coherent Amplification Network) Laser System Mourou et al. 2013, nature Photonics, 7, 258-261

14. Space CAN laser system CAN=Coherent Amplify Network

15. A ROADMAP TO DEBRIS CLEANING 1.Mini-EUSO on ISS – Proof of Principle Mission – 25 cm UV telescope 2.EUSO class telescope (K-EUSO) on ISS – Technical Demonstrator for Laser Removal – 2.5 m UV telescope CAN Laser System 3.Dedicated Removal Mission – Tandem Configuration of EUSO and CAN laser – Polar orbit with 800 km altitude

16. 1.EUSO-TA: Ground detector at Telescope Array site: 2013- 2.EUSO-BALLOON: 1st balloon flight from Timmins, Canada (French Space Agency CNES) Aug 2014 3.MINI-EUSO (2017) 4.K-EUSO (2019) 5.JEM-EUSO (>2020+) The EUSO program JEM-EUSO 14 o MINI-EUSO EUSO-TA (2013-)

17. Balloon Flight 2014 August 23

18. Laser flasher event

19. 1. Mini-EUSO Proof of principle system Selected by ASI (ITALIAN SPACE AGENCY) asVUS-2 (Human Space Flight 2) Russian International Collaboration mission – long-term program of space experiments on the ISS Detection Tracking – and Irradiation by Lidar (if possible)

20. Mini-EUSO LOCATION Experiment “Relaxation” on the ISS 15th International JEM-EUSO Meeting20 Mechanical interface with UV window could be similar.

21. 2.EUSO class telescope on ISS Enlarge FoV ±7°→±14° Pixel size 4 times finer Technical demonstrator of Laser Removal EUSO class telescope →KLYPVE/K-EUSO + 1.5 m Cassegrain for tracking CAN laser system 100 kW and 10 4 Hz Operation Range: 100 km 10 (Backward)-300 (forward) debris/yr

22. KLYPVE/K-EUSO In the Russian Federal Space Program Passed the stage of preliminary design with Roscosmoc Technical requirements, accommodation, operations study performed by Energia space corporation Launch in FY 2019

23. Location on ISS Mini Research module MRM-1 LENS Electronics of FS

24. This experiment is in the Federal Space Program We passed the stage of preliminary design (pre- phase A) The technical requirements (specification) based of the preliminary design are written.

25. Status KLYPVE/K-EUSO in Japan Japan – Corrector lens, Photomultipliers, and Laser head (atmospheric monitoring LIDAR) – Passed Mission Definition Review (April 2014) System Requirement Review (April 2015)

26. ISS orbit (~400km)

27. 3. Dedicated Debris Removal System Polar orbit from 1000 km→600 km 2.5 m EUSO + Space CAN laser (500 kW) Operation Range: 100km 10 3 (backward)-10 5 (forward) operation Most of debris (0.5-10 cm can be removed)

28. Reduction in orbit radius by an operation

29. Polar orbit (~800 km)

30. Parameters of Systems Prototype on ISS Technical Demonstrator on ISS Dedicated system Target Debris Size (cm)>110>a>0.5 Target Debris Distance (km)10-100100 EUSO Aperture (m)0.252.5 EUSO FoV±14°±30° Tracking Optics (m)0.11.5 Laser systemSolid state10 4 fibre Pulse Energy (J)0.110 Pulse Duration (ns)10.1 Repetition rate (Hz)0.11000050000 Average power (kW)0.001100500 Event per year20-30 (detection) 2-3 irradiation) 10 (backward) 300 (forward) 10 5 (forward) 10 3 (backward)

31. Summary Reentry by Laser Ablation: 1-10 cm Laser ejection from Space craft – Detection EUSO telescope Super wide field （～ 60° ）, super high speed （ ~microseconds ） – Tracking system of 1.5 m and CAN laser (100-500 W) – 355nm UV laser Three steps – Mini-EUSO: IUV window on ISS – EUSO+ CAN laser on ISS – Dedicated free flyer polar orbit 1000 km→500 m

32. Many Challenges Build High Power Space Laser – High power efficiency:~30% – High repetition Rate:~50,000 Hz Tracking Optics – Diffraction Limited Optics (λ=355nm) – Rapid Move (1degree/s) – Power Tolerance Software (full automatic) – Detection to Shooting – Characterization Safety Issues,,,,,

34. Suppression of Rotation

35. Results of simulations for 1-10cm size debris, performed with the MASTER 2009

36. Reaction Force of Ablation Lindahl et al. 2013

37. Safety Issues? Just Above the Ablation Threshold – Focusing to the target on 0.02m to get 10000 W m -2 – Effective only ±1 km from the target Eye Safety? – Outside 400-710 nm Average Power – Solar constant: 1.366 kW m -2 – ISS demonstration:100 kW→1kW m -2 at 100km – Dedicated system: 500 kW→1kW m -2 at 200km

38. Balloon Experiment 2014 August CNES+JEM-EUSO Collaboration

39. Helicopter equipped with laser and xenon flasher (NASA funding)

40. Balloon Experiment 2014 August CNES+JEM-EUSO Collaboration

41. Balloon Flight 2014 August 23

42. Helicopter equipped with laser and xenon flasher (NASA funding)

43. Laser flasher event

44. Optical Test

45. Laser track Event profile

46. 無事着水

47. Debris Flux at ISS orbit (~400 km)