Low-Noise Thrust Generation by Laser-Ablative Micropropulsion

Aiming for the generation of high-precision thrust in the μN range, laser- induced ablation of propellant material is employed in order to reduce thrust noise by avoiding moving parts inside the thruster. Focused high-intensity laser pulses are used for thrust generation by the recoil of the jet of the ablated material. Whereas a single laser pulse yields an extremely low impulse bit down to 1 nNs in a 40 μ mf ocal spot on aluminum, a broad thrust range can be accessed by the variation of the laser pulse repetition rate up to several hundreds of kilohertz. Thrust measurements with a highly sensitive torsional balance, calibrated by photon pressure, yield coupling coefficients up to 15 μN per Watt average laser power and beyond. The concept of 3D electro-optical beam- steering is discussed which is essential to ablate every part of the propellant. A detailed study for the determination of the optimum laser parameters is carried out.

[1]  Junya Kobayashi,et al.  Charge distributions in KTa₁₋xNbxO₃ optical beam deflectors formed by voltage application. , 2014, Optics express.

[2]  O. Rosmej,et al.  Dynamics of thin metal foils irradiated by moderate-contrast high-intensity laser beams , 2012 .

[3]  A. Tünnermann,et al.  Femtosecond, picosecond and nanosecond laser ablation of solids , 1996 .

[4]  Munekazu Date,et al.  High speed optical deflector with sub-micron droplet polymer dispersed liquid crystal , 1995, Technical Digest. CLEO/Pacific Rim'95. The Pacific Rim Conference on Lasers and Electro-Optics.

[5]  N. G. Semaltianos,et al.  Single-pulse drilling study on Au, Al and Ti alloy by using a picosecond laser , 2009 .

[6]  Michael Tsay,et al.  Micro RF Ion Engine for Small Satellite Applications , 2009 .

[7]  Claude R. Phipps,et al.  3ks Specific Impulse with a ns-pulse Laser Microthruster , 2005 .

[8]  Marisa N. Faraggi,et al.  Electron emission from metal surfaces by ultra-short pulses , 2007 .

[9]  D. Bäuerle.  Laser Processing and Chemistry , 1996 .

[10]  Stefan Scharring,et al.  Overview of Laser Ablation Micropropulsion Research Activities at DLR Stuttgart , 2014 .

[11]  S. Edwardson,et al.  Effects of laser operating parameters on metals micromachining with ultrafast lasers , 2009 .

[12]  Bernd Hüttner,et al.  On the theory of ps and sub-ps laser pulse interaction with metals. II. Spatial temperature distribution , 1998 .

[13]  Claus Braxmaier,et al.  Feasibility of a down-scaled HEMP-Thruster , 2011 .

[14]  Stefan Scharring,et al.  Open Access Tools for the Simulation of Ultrashort-Pulse Laser Ablation , 2014 .

[15]  C. Kittel.  Introduction to solid state physics , 1954 .

[16]  H. Seifert,et al.  Rocket Propulsion Elements , 1963 .

[17]  Masahiro Ueno,et al.  First Estimation of Power Consumption of KTa , 2013 .

[18]  Hans-Albert Eckel,et al.  Laser Propulsion Research Facilities at DLR Stuttgart , 2014 .

[19]  D. Batani,et al.  Laser Ablation and Laser Induced Plasmas for Nanomachining and Material Analysis , 2008 .

[20]  R. Leach,et al.  Discussion of Micro-Newton Thruster Requirements for a Drag-Free Control System , 2002 .

[21]  S. Anisimov,et al.  Electron emission from metal surfaces exposed to ultrashort laser pulses , 1974 .

[22]  John E. Sinko,et al.  Applying New Laser Interaction Models to the ORION Problem , 2010 .

[23]  Kazuo Fujiura,et al.  Electro-optic KTN Devices☆ , 2014 .

[24]  Yosuke Tsukiyama,et al.  CO2 Laser Ablation Area Scaling and Redeposition on Flat Polyoxymethylene Targets , 2010 .

[25]  Geunyoung Yoon,et al.  Use of a microelectromechanical mirror for adaptive optics in the human eye. , 2002, Optics letters.

[26]  Leonard D. Cassady,et al.  Performance Measurements and Technology Demonstration of the VASIMR ® VX-200 , 2010 .

[27]  Max M. Michaelis,et al.  Review: Laser-Ablation Propulsion , 2010 .

[28]  Kazuo Fujiura,et al.  Wide-angle, low-voltage electro-optic beam deflection based on space-charge-controlled mode of electrical conduction in KTa1−xNbxO3 , 2006 .

[29]  Hiroshi Miyajima,et al.  A MEMS electromagnetic optical scanner for a commercial confocal laser scanning microscope , 2003 .

[30]  Seiji Toyoda,et al.  Trapped charge density analysis of KTN crystal by beam path measurement. , 2014, Optics express.