Charles Talleyrand wrote:
I'm trying to imgaine cheap space flight. I'd also like to see it
sooner rather than later. Given this I believe we are limited to
chemical rockets.

What's the cheapest cost to orbit a chemical rocket is likely to
yield in the next fifty years? Will we see $100/pound to orbit?
How about $10/pound? And what underlying technology will
this rocket use?

Note: Please avoid the use of wormholes and unobtanium. Please
don't say "carbon nanotubes will solve everything" unless you also
believe that we will build 50,000 lbs structures in carbon nanotubes
sometime in the next 50 years. We're looking reasonably far into
the future (50 years or less) but trying to limit ourselves to chemical
rockets and things that can actually be built and used.



This is frequently discussed on sci.space.policy.

Some believe if rocket engines were massed produced economies of scale
would make launch expense much less.

They are hoping the X-prize contenders will open a new industry of space
tourism, and that many would pay to enjoy sub orbital flight into near
earth space just as people paid to enjoy rides with barn stormers in the
early days of aviation.

It's argued that a free market could make rockets common just as it has
done for motor cars, airplanes, and computers.

If rocket engines become very affordable, the expense may be dominated
by fuel. I believe your fuel to payload ratio is e^(Vf/Ve) where Vf is
final velocity and Ve is exhaust velocity. IIRC 4 km/sec is good exhaust
velocity for chemical rockets. And 8 km/sec is an orbital velocity. So
e^(8/4) = e^2 = about 7.4. So you'd need more than 7 times the mass of
your payload in fuel.

Another obstacle is government regulation. I can see the need for
regulation but some sci.spacers argue that existing regulations will
smother the space tourism industry before it's born.

--
Hop David
http://clowder.net/hop/index.html