Re: nanoaluminum/SSTO Re: Confronting The Singularity Conference

From: Michael S. Lorrey (retroman@turbont.net)
Date: Fri May 26 2000 - 23:11:41 MDT


Brian Atkins wrote:
>
> 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
>
> Right, they seem to be partnering though with a large industrial
> partner that will allow them to produce tons of it per day. They
> apparently are patenting the manufacturing process.
>
> > 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.
>
> Well I am not a rocket scientist :0 But I can scan in a chart from their
> business plan (or perhaps it is on their old site at nanopropulsion.com)
> showing how their system is waaay better than the shuttle or other methods.
> The idea is that the nanoaluminum allows for a much denser mix with the
> other materials in the fuel, and therefore much faster reaction rates
> and therefore much much higher thrust than what you get from conventional
> mixing techniques. Also they go on about how this would also allow for
> nozzleless rockets that could even consume their casing on the way up.
> There would be no "hole" in the center of the fuel, it would just burn
> at the end. What do you think?

Cast it on the rear of a vehicle that has an aerospike hull going down
thru the fuel. Once it reaches supersonic speeds, the shock wave will
contain the burning and generate thrust, but I don't see how it won't
just let the fire crawl up the sides at subsonic speeds. You'd have to
have some kind of containment shell near the lower end to prevent this
until it reaches at least mach 2 I'd guess.

>
> >
> > One problem with metallized solid propellants for tactical missiles is
> > "signature"- they burn *damn* hot and have a very bright plume (consider
> > the shuttle SRBs). This serves to warn the target that you've just
> > launched, enabling him to take countermeasures. A major focus in new
> > hypervelocity missile developement is low-observable propulsion, which
> > has a purely gaseous exhaust with low luminosity.
>
> They seemed to think their biggest problem is that the missle tracking
> systems are unable to handle the higher speeds.

How much higher speeds are we talking about? It would be really nice to
be able to finally realize the Thor system of hypersonic crowbars.

Mike Lorrey



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