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Laser Astronaut Retrieval Propellant Development Tyler Baxter 1 , John E. Sinko 1,2 , Clifford Schlecht 2 , and Mark Gill 3 ¹ Dept. of Physics and Astronomy, Saint Cloud State University, St. Cloud, MN 56301 ² Institute for Materials, Energetics and Complexity, St. Cloud, MN 56301 ³ ISELF 3D Printing Coordinator, Saint Cloud State University, St. Cloud, MN 56301 MOTIVATION The development of the aerospace industry has recognized the need for a method of retrieving both assets and humans in the vacuum environment. This experimental process explores and refines the idea of using lasers to create a ‘tractor beam’ retrieval effect by controlled laser ablation using low- cost, low-risk propellant alternatives. EXPERIMENTAL PROCEDURE To demonstrate quantitative propellant thrust, an improvised 3D-printed ablatant chamber casing was housed directly atop a force sensor capable of measuring a thrust response. All components were sealed under a vacuum chamber in which we plan to simulate low-Earth orbit vacuum conditions. Acknowledgements This project was funded by the authors and by Saint Cloud State University. The authors would also like to express thanks to Dr. Michael Dvorak and Dr. Michael Jeannot of the Saint Cloud State Chemistry Department for their input. 1. Target Irradiation Targets were exposed to 30-seconds of 3 watts continuous laser output at a wavelength of 514.5 nm. 2. Target Ablation Following direct exposure, ablatant targets offgas residual chemical products that fill the volume of the ablation chamber. 3. Coordinated Confinement Residual byproducts of the ablation process are directed Figure 1. Ablation casing diagram. References 1.National Aeronautics and Space Administration, NASA Strategic Plan 2014, pp. 3, 11. 2.S. Yokoyama, H. Horisawa, I. Funaki, and H. Kuninaka, “Fundamental Study of Laser Micro Propulsion Using Powdered-Propellant” in International Electric Propulsion Conference, IEPC-2007-230, pp. 1-7 (2007). 3.C. R. Phipps, J. R. Luke, G. G. McDuff, T. Lippert, “Laser-driven micro-rocket”, Appl. Phys. A 77, pp. 193-201 (2003). 4.M. S. Egorov, Yu. A. Rezunkov, E. V. Repina, and A. L. Safronov, “Laser corrective propulsion plant for spacecraft”, J. Opt. Technol. 77(3), pp. 159-164 (March 2010). 5.9. J. T. Kare, “Laser Powered Heat Exchanger Rocket for Ground-to-Orbit Launch”, J. Figure 2. Ablation of propellant. Figure 3. Dispersion of byproducts into casing microtubule. RESULTS Using a carbon nanofoam propellant: Figure 4. Experimental ‘tractor beam’ thrust response for carbon sample. Figure 5. Magnification (80x) of carbon foam propellant sample. Figure 6. Carbon foam propellant casing. Using a thin film ammonium carbonate propellant: Figure 7. Size representation of the ammonium carbonate ablation casing. Figure 8. Magnification (2.5x) of ammonium carbonate crystals. Figure 9. Live ablation of ammonium carbonate target in vacuum. ANALYSIS AND FUTURE WORK Although the experiment was successful, several further methods of refinement are possible. Future work will include design of an ablation casing with a re-sealable gasket to allow for swift comparison of other carbonate-related compounds and minimal loss of desired offgassed products. Figure 10. Carbon ablation target irradiated by 514.5nm photons.
