DTIC ADA469986: Laser Powered Thrusters for High pdf

DTIC ADA469986: Laser Powered Thrusters for High

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Description of the Book:

Our objective is to develop an engine with high efficiency, and specific impulse which can be varied over more than an order of magnitude to match the requirements of efficient spacecraft propulsion in the constant momentum propulsion regime. Laser ablation propulsion uniquely offers an almost arbitrarily large range of exhaust velocity, since it depends only on incident laser intensity. We have shown that thrust efficiency remains good over the specific impulse range 150 to 3,200 seconds. Considering a laser ablation propulsion device as an electric thruster, use of energetic ablation fuels can give thrust electrical efficiency greater than unity at the bottom of this Isp range. In our laser plasma thrusters (LPT’s), we have demonstrated specific impulse which can be varied over a factor-of-15, from 200 to 3000 seconds to match the velocity profile in a mission. The corresponding thrust efficiency varies from 165% to 40%. The micro-LPT product has a 0.1 – 10 mN thrust range.

After reviewing the science basis and performance of the existing devices, we describe the unique capabilities predicted for the LPT technology when it is scaled to the 1N thrust level. This scaling permits taking full advantage of the technology’s inherent advantages in thrust/power ratio (up to 1.35N/kW), thrust efficiency and thrust density (5,000 to 350,000N/m2). However, the most important capability of the macro-LPT design is variable Isp for optimally-efficient, constant-momentum flights. Claims made for the macro-LPT are based on measured performance of our millisecond and nanosecond-pulse LPT devices, and the anticipated performance of a revolutionary liquid ablation fuel

• Creator/s: Defense Technical Information Center
• Date: 4/10/2007
• Year: 2007
• Book Topics/Themes: DTIC Archive, Phipps, C R, PHOTONIC ASSOCIATES SANTA FE NM, *LASER APPLICATIONS, *ELECTRIC PROPULSION, ABLATION, SYMPOSIA, LASER PRODUCED PLASMAS, SPACE PROPULSION, THRUSTERS, NITROGEN

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