🚀 go-pugleaf

-From: Bruce_Dunn@mindlink.bc.ca (Bruce Dunn)
-Subject: Re: Aluminum as Rocket Fuel?
-Date: 4 Jan 93 00:27:49 GMT
-Organization: MIND LINK! - British Columbia, Canada

-        Sorry for the sloppy wording.  I meant rather "when there is melted
-aluminum in the tank".  I am envisioning a system in which aluminum is
-premelted, possibly in a solar furnace, and poured into an insulated
-tank/valve/combusion chamber unit.  The aluminum will bring the whole system
-up to temperature, and melt any residual aluminum from the last firing.  

Getting an aluminum engine that will work in single-use mode is the first big
step. Making one that can be restarted and reused is a significant further
challenge, which is not necessary to putting aluminum engines in service for
launch from the moon.

-I expect that it won't be too hard to insulate the assembly well enough to keep
-the temperature above the melting point of aluminum for days.  I don't think
-that a heater will be required.  

That's probably correct, though you need to watch out for the possibility
of chemical reactions and leaks when storing molten aluminum for long periods.

-If heating is required for long term
-operation, the logical thing would be to admit a small amount of oxygen into
-the fuel tank to react with the aluminim and heat it.

If you do that, there's a very good chance you'll clog up whatever you're
using to inject the aluminum into the combustion chamber.

John Roberts
roberts@cmr.ncsl.nist.gov