From: Michael S. Lorrey (retroman@turbont.net)
Date: Fri May 26 2000 - 21:54:36 MDT
Doug Jones wrote:
>
> Brian Atkins wrote:
> >
> > It was quite evident that nanotech is gaining steam. Technanogy sponsored
> > the event, they are a nanotech incubator backed by Ted Waitt (of Gateway
> > computers). Their first project is "nano aluminum", which in its first
> > application is the creation of super high thrust solid rocket fuel. Think
> > single stage to orbit at $50 to 100 a pound. But for starters they are
> > working on refitting stingers and other conventional weapons.
>
> Nanopowdered aluminum is not all that remarkable- there's a product
> called AlEx or some such which is nanoscale aluminum powder made by
> exploding a wire with a capacitor discharge in a helium atmosphere. It
> has a slightly positive heat of formation relative to bulk Al, but solid
> fuels are inherently a poor match for orbital launch- you get better Isp
> and effective bulk density out of liquid fuels, and for SSTO or even a
> cheap TSTO, delta-V is most important. Solids are great for tactical
> propulsion (ie missiles) but just can't compete with liquids for system
> bulk density, mass fraction, and Isp.
This is something I've wondered. If liquid fuel is so much better, why
does the shuttle, the Delta, the Araine, the Titan, etc all need solid
boosters to get decent enough mass fractions to put decent payloads in
orbit? I was wondering if people were biased toward hydrogen merely for
purists sake. Sure you get great Isp, but you get great Isp from an ion
engine too, and you wouldn't want to power a launch system with an ion
engine.
Mike Lorrey
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