High efficiency drives

What is funny is I have no way of complying with your request at the
moment. I have no windows machines at my house, and the zip program on
unix doesn't produce a file that pkzip can uncompress.

I'll get it into a zipfile and post it.

To give you an idea of what I was trying to accomplish, imagine what
infrastructure you will need to move half a million people into space
a day.

This included things like ground transportation/storage large scale
launch facilities, construction requirements for housing, factories,
ships, power equipment.

With half a million people to huase in space every day, you have to
build a Oneil cylinder every day.

Bill

--- In spacesettlers@egroups.com, "Tom Tucker (Olympia)"
wrote:
> Bill,
>
> Thanks for the input. This may come as a shock to you, but some of
us do not use unix and so we have no way of uncompressing the .tar.
file you are referencing. Can you unpackage PKZip files? I wonder if
this wouldn't be a more universal archive?
>
> My list's goal was to identify "missing technological links"
preventing the deployment of space colonies. Some of your items
appear to be "nice to have" rather than essential.
> From: bill t
> To: spacesettlers@egroups.com
> Sent: Thursday, December 28, 2000 8:00 AM
> Subject: [spacesettlers] Re: High efficiency drives
>
> If you want a more comprehensive list, go to the file section and
> download a file called evacuation.tar.gz. In there you will find a
> file called details.html. This has a more comprehensive list.
>
> To your list add,
> space agriculture (covered under #3)
> power management (heating, cooling, microwave beaming, electrical
> discharging etc...) (Also convered under #3)
> search and rescue (future nice idea)
> space ship production (NASA already does a pretty good job)
> asteroid discovery program (inprocess, but may take decades to
complete)
> asteroid retrieval program (future goal)
> information system (expert system) (future nice idea)
> advanced robotics (covered under #2)
>
> Please explain your rational why the balance of your list above
are critical and not amenities that can be developed after deployment
of a space colony?
>
> Cheers,
>
> Tom
>
> Bill
>
> --- In spacesettlers@egroups.com, "Tom Tucker (Olympia)"
> wrote:
> > Mike,
> >
> > So, what would you power your mass driver with? Nuclear fission?
> Chemical? Solar? What diameter projectile? What velocity do you
> anticipate achieving for the projectile?
> >
> > Keeping alternatives on the table helps with comparative
analysis
> later when more options are available.
> >
> > Being more pragmatic, I think that we are many decades away from
> space colonization and asteroid mining due to critical "missing
> technological links" in the chain of tools that are needed.
Chiefly,
> these are:
> >
> > 1) Reduction in cost to achieve LEO and beyond,
> >
> > 2) Advanced remote technology to mine and to maintain mining
> equipment on an asteroid that may be far far away. Neural net
> ethnology will be crucial IMO along with VR and machines able to
> repair themselves.
> >
> > 3) Design and test viable life support systems for space
colonies.
> >
> > The above steps will open the frontier to space colonization
IMO.
> Am I missing any steps? Comments?
> >
> > Cheers,
> >
> > Tom
> >
> > From: Mike Combs
> > To: spacesettlers@egroups.com
> > Sent: Wednesday, December 27, 2000 6:49 AM
> > Subject: [spacesettlers] High efficiency drives
> >
> >
> > --- In spacesettlers@egroups.com, "bill t"
> > > >
> > > The resource in the asteroid are vast, but so are the ones
on
> > earth.
> > > The earth represents at least 9 orders of magnitude more
> material
> > than
> > > all the asteroid combined.
> >
> > Yes, but here on Earth we're limited in how deep we can mine
> before
> > pressures and temperatures become problematic. Not so in
> asteroids.
> >
> > > If you can effectively mine the first
> > > kilometer of the surface you will get everything you need,
> assuming
> > an
> > > energy source can be found.
> >
> > Yes, but think about what's being said here. Imagine the
> > environmental disruption of even developing half of that. One
of
> the
> > advantages of any kind of space mining is that it can take
place
> at
> > any scale with 0 disturbance of the Earthly biosphere.
> >
> > > Again, no. If you are looking for a continuous acceleration
> engine
> > for
> > > interplanetary travel, you can achieve this by using solar
> powered
> > > electric generators, to charge dust particles, then
accelerate
> the
> > > dust using an electric field.
> >
> > There are lots of proposals out there for all kinds of low-
> > thrust/high-efficiency drives. This writer happens to have a
soft
> > spot for mass driver engines, but it might be too early to say
> that
> > it's definitely going to be this or that.
> >
> > My only criticism of fusion drives might be that we don't know
how
> to
> > do fusion yet, so it might be better to first concentrate on
the