[ExI] Power satellites

spike spike66 at att.net
Sat May 2 18:03:21 UTC 2009


> ...On Behalf Of Stefano Vaj
> Subject: Re: [ExI] Power satellites
> On Sat, May 2, 2009 at 6:53 PM, Eric Messick 
> <eric at m056832107.syzygy.com> wrote:
> > Well, actually there is an absolute physical limit.  Get 
> the mass of 
> > the 'planet' up high enough, and you get an event horizon.  I'll 
> > admit, the limit is pretty far from where we are, but it is there.
> Yes, this also came to my mind. But even much below that 
> limit, can we actually lift wood to orbit by making use of 
> the energy that can be extracted by burning it, if we are not 
> concerned with the relative size of the payload? :-/
> --
> Stefano Vaj

Oh, ja if we are near black hole scales, we can't get there outta that
gravity well.  We can't even talk to the stellar neighbors, never mind
visiting them.

Can we make a wood burning rocket?  Yes.  You would take your logs, grind
them to dust finer than flour, blow that into a heated pressurized chamber
with only hydrogen present, then load that product aboard your rocket, pump
it into your combustion chamber with LOX at about 6 atm, boom, up you go.
Or just start with flour instead of wood, this being sufficiently similar
chemically for this purpose.

If you are asking could you use wood as a rocket fuel in the form of two by
fours?  Sure, take it up to almost orbit velocity in the traditional
fashion, burn your two-bys in a chamber with pure oxygen, dump the heat into
xenon or better yet radon as your propellant, pick up some delta vee.  Or
you could dump the hot CO2 and H2O out the back as your propellant too if
you prefer.  It would be far better to preprocess your wood on the ground
however, put all that carbon to work carrying hydrogen.  

I pulled a fast one on you with that first idea.  By grinding and adding
hydrogen and energy, you functionally convert the wood to kerosene, which is
what the Saturn first stage burns.  Stefano, good thing for me you have a
sense of humor.  {8^D  I love rocket jokes.  Oy, I am such a geek.


More information about the extropy-chat mailing list