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- From: rudiak@garnet.berkeley.edu
- Newsgroups: alt.alien.visitors,alt.paranet.ufo,sci.skeptic
- Subject: Re: MHD article
- Date: Tue, 18 Jun 1996 22:41:19 GMT
- Organization: University of California, Berkeley
- Lines: 74
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-
- Jim Rogers <jfr@fc.hp.com> wrote:
-
- >Brian Zeiler wrote:
- >>
- >> http://www.rpi.edu/dept/NewsComm/Review/may/may05/space.html
-
- >Cool! Pity no actual publication was cited. I'd love to learn about
- >this, if it's for real.
-
- Here are abstracts from two recent conference talks by Myrabo.
-
-
- 1. CONFERENCE PAPER
- Myrabo, L.N. Hyper-energetic manned aerospacecraft propelled by
- intense pulsed microwave power beam. (Intense Microwave Pulses III,
- San Diego, CA, USA. 10-12 July 1995).Proceedings of the SPIE - The
- International Society for Optical Engineering, 1995, vol.2557:193-208. Pub.
- Type, practical.
-
- Abstract: The objective of this research was to exploit wireless
- power transmission (microwave/millimeter)-to lower manned space
- transportation costs by two or three orders of magnitude. Concepts
- have been developed for lightweight, mass-producible, beam-propelled
- aerospacecraft called Lightcraft. The vehicles are designed for a
- "mass-poor, energy-rich" (i.e., hyper-energetic) flight
- infrastructure which utilizes remote microwave power stations to
- build an energy-beam highway to space. Although growth in laser power
- levels has lagged behind expectations, microwave and millimeter-wave
- source technology now exists for rapid scaling to the megawatt and
- gigawatt time-average power levels. The design exercise focused on
- the engine, structure, and receptive optics requirements for a 15
- meter diameter, 5 person Earth-to-moon aerospacecraft. Key elements
- in the airbreathing accelerator propulsion system are: a) a "flight-
- weight" 35 GHz rectenna electric powerplant, b) microwave-induced
- "Air Spike" and perimeter air-plasma generators, and c)
- MagnetoHydroDynamic-Fanjet (or MHD-Fanjet) engine with its
- superconducting magnets and external electrodes.
-
- 2. CONFERENCE PAPER
- Benford, J.; Myrabo, L. Propulsion of small launch vehicles using
- high power millimetre waves. (Intense Microwave Pulses II, Los
- Angeles, CA, USA, 24-26 Jan. 1994). Proceedings of the SPIE - The International
- Society for Optical Engineering, 1994, vol.2154:198-217. Pub type: Practical;
- Experimental.
-
- Abstract: The use of microwave and millimeter wave beamed energy for
- propulsion of vehicles in the atmosphere and in space has been under
- study for at least 35 years. The need for improved propulsion
- technology is clear: chemical rockets orbit only a few percent of the
- liftoff mass at a cost of over $3000/lb. The key advantage of the
- beamed power approach is to place the heavy and expensive components
- on the ground or in space, not in the vehicle. In the past two
- decades, microwave sources have been developed to extraordinary peak
- powers over a wide frequency range and are now operating at
- repetition rates in excess of 100 Hz, giving average powers of
- approximately 10 kW.1 This paper, following upon the high power laser
- propulsion programs, uses a multi-cycle propulsion engine in which
- the first phase of ascent is based on the airbreathing ramjet
- principle, a repetitive Pulsed Detonation Engine (PDE) which uses a
- microwave-supported detonation to heat the air working fluid, i.e.,
- propellant. The second phase is a pure beam-heated rocket. The key
- factor is that high peak power is essential to this pulsed engine.
- This paper explores this propulsion concept using millimeter waves,
- the most advantageous part of the spectrum. We find that efficient
- system concepts can be developed for the beam powered launch system
- and that, while the capital cost may be as high as the earlier
- orbital transfer concepts, the operating cost is much lower. The
- vehicle can have payload-to-mass ratios on the order of one and cost
- (per pound to orbit) two orders of magnitude less than for chemical
- rockets. This allows the weight of microwave powered vehicles to be
- very small, as low as approximately 100 kg for test devices.
-
-
-
-