🚀 go-pugleaf

In article <1i5nafINN96k@uwm.edu> anthony@csd4.csd.uwm.edu (Anthony J Stieber) writes:
>No one has mentioned using a cylinder of aluminum with perhaps a star
>shaped core and spraying LOX down it.  The aluminum is both the fuel
>and structure.  Running it until much before burn through is probably a
>bad idea, but it may be cheaper than importing steel shells from earth.

I'm posting this because Tony bothered me into catching up on sci.space
by talking about this post for a while 8-)

Solid aluminum burns just fine, but it has a really poor regression
rate (it burns very very slowly).  The best way to do this would be to
bunlde aluminum wire in a combustion chamber to increase the surface
area so that you get decent thrust.

The primary problem of a steel combustion chamber is that combustion
will be hot enough that LOX will definitely be burning with steel
as well as aluminum.  I don't know what I'd do, perhaps a ceramics
lining.

And, as much as you people hate to have reality dropped on a conversation,
aluminum is the wrong fuel to use if it's an earth based application.
A General Dynamics report on Hybrid replacements for the Space Shuttle SRBs
indicates that Zinc  is a better solid to burn; it's a whole lot more
dense, a lot cheaper, and it's Isp is nearly the same (density Isp is
a whole lot better). (NASA Contract NAS8-37777)

-george william herbert
Retro Aerospace
2240 Blake #101
Berkeley CA 94704