On Wed, 2 Jul 2003, Christopher England wrote:
> Ion propulsion is efficient but low in thrust (like ounces of force). > Chemical propulsion will be needed for high thrust needs like fast > orbital capture, landing and takeoff. Chris, has anyone done an analysis to determine whether one could produce a high-thrust ion engine "complex" using nanotech? An analysis of nanotechnology based engines (non-ion) for air-cars [1] seems to suggest they would be much more efficient than engines based on current technology. What do we know about nanotech based ion-tech? My guess would be that there would be significant gains in thrust due to multiple micro-engines but that this might be limited due to things like voltage and insulator constraints. I also suspect that your comments regarding radiator limitations and the need for refractory metals may be somewhat "current technology" based. See [2]. We are not close to the limits of cooling technology at this time. If one can improve the cooling technology, one might be able to run the reactor somewhat hotter without risking a meltdown and as a result increase thermodynamic energy conversion efficiency. Interestingly, if one wants a cooling system with the highest temperature tolerance, the substances one would prefer to make it out of would seem to be (a) Hafnium carbide; (b) Tantalum carbide; (c) Tungsten or if one wants something a bit less expensive perhaps Titanium carbide. So refractory metals would seem not to be strictly necessary. Robert 1. Hall, J. S., "Molecular Manufacturing and the Private Aircar", http://discuss.foresight.org/%7Ejosh/aircar/ See esp. "Engines power-to-weight ratio". 2. Henson, H. K., and K. E. Drexler. (1988) Heterodensity heat transfer apparatus and method. U.S. Patent Office: #4,759,404 Discussed in some more detail in: Drexler, K. E., "Nanosystems", J. Wiley & Sons, New York (1992) esp. Section 11.5, pgs 330-332. == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
