Re: starship-design: build it now...

[Johnny Thunderbird <jthunderbird@nternet.com>]

"Curtis L. Manges" wrote:

> Stravonski@aol.com wrote:
>
> > In a message dated 04/06/99 16:21:01 Mountain Daylight Time,
> > bfranchuk@jetnet.ab.ca writes:
> >
> > << Sure I am game to build it now...
> >    But we do seem to be lacking in finding a small reusable launch
> >  rocket... >>
> >
> >         Excellent, then we know what areas we need to focus on.  Does anyone
> > else know of any holes in our plans?
> >
> > Mike Pfeifer
>
> The small, reuseable launch vehicle is in aggressive development. See
> www.rotaryrocket.com.
>
> Keep looking up,
>
> Curtis

I enjoy turning notions on their heads. Instead of a totally reuseable
launch vehicle, I came up with a totally expendable launch system,
all made of fuel except for the payload. Since efficiency is ultimately
the basis of cost, you won't get much cheaper launch to orbit, than
with the Paper Cannon concept.

It's not really paper after it's been nitrated, it's nitrocellulose, like
guncotton. And it's not really a cannon at all, but a shock tube,
meant to squirt the slug of hydrogen gas contained within it, at
hypersonic speeds, through the air. This breeze blows past the
chunk of hydrogen ice which is fastened to the payload,. but this
package catches up very soon, by mixing and igniting the column
of hydrogen behind it. When the head of the jet of gaseous
hydrogen has been passed, and all is burned behind it, the payload
package rides on a chunk of solid hydrogen ice, which rapidly
dwindles because it is the final stage fuel.

The Paper Cannon, as I call it, will get your cargo  in orbital
momentum space real cheap, and there's nothing left to worry
about, whether you should reuse it or not. The sleeve was gasified
as it imploded, to squeeze its contained hydrogen forward in a
big rush. The resulting jet of hydrogen was all consumed, by
the traverse of the payload and cryofuel package, inducing
turbulence and ignition in its wake. The solid hydrogen ice
was ablated and ignited by all that fire behind it, and the payload
then sailed naked into space. By designing from fundamentals,
we reduced the rocket mass to zero.

Like that one? Care to help with the math? Of course it isn't
very accurate, but adjusting your orbital paramters can be
done leisurely when you don't have to worry about falling
down, nor about shoving your way through a lot of
thick air. I posted this on the Beanstalk board, at
http://www.insidetheweb.com/messageboard/mbs.cgi?acct=mb153173
so drop in and see the scheme. Say hi to Allen over at the Virtual
Beanstalk Project. He wants to launch from stratospheric height,
from a tethered aerostat platform. Tell him I sent you.
http://members.aol.com/beanstalkr/project project home page.

That sleeve, a.k.a. paper cannon, was originally puffed out of
a launch tube by compressed hydrogen. The hydrogen ice and
payload package beat it out, like a pea coming out of a peashooter,
before the bottom of the sleeve was ignited, to start up the seriously
speedy stuff. The payload package burns its way up a low
pressure lane of pure hydrogen. Its fuel is all laid out in front
of it, in its path, so all it has to do is mix it and burn it. That trick
it pulls easily, by virtue of being a solid body passing through.

The final stage, the solid hydrogen ice fuel tacked to the payload,
forms the simplest external combustion SCRAMJET, and probably
the simplest reaction engine. The combustion chamber is formed
of that handy hypersonic shock wave coning around it, tough stuff
even if you can see through it. The fuel sublimes and ignites. This
is hydrogen ice, after all, on top of a great big bonfire, inside of
an oxidizing atmosphere. It sublimes, it ignites. It goes on, out to
where the oxygen peters out. Then you're in the gravy, for your
package is in orbit, and there's no mess to clean up.

Keep it lite,
Johnny Thunderbird
http://www.dejanews.com/~liteage