Re: SF rocket propulsion?

IF you go through the below and count how many times you used the word
"if" or "depends on" below, you'll see where I get my skepticism.




Stephen Horgan wrote:
Ordover@xxxxxxx wrote:

I think that commercial development of space flourishes where it
provides a service for the customers on Earth at a profitable rate. If
you doubt that's what I said, re-read this thread. Comsats do that.
Something else that does that that is as yet unthoughtof would do it
too. If you doubt that's what I said, re-read the thread.

There is no doubt that market economics are the best driver for any new
field of endeavour, but everything has to start from somewhere.

And that place is the percpetion of immediate economic value.

It depends what you mean by 'immediate'. There are commercial space
ventures that do not expect a return for years.


Fifty
years ago there was no space-based economic activity at all. Now the
sector is worth many billions and is expanding year on year, with
multiple applications and supporting services.


All based on providing mass-market services to the customers on Earth
(save for the military applications). Comsats, GPS, etc.

A rapidly expanding space industry. Where science and exploration led
then commerce followed. Why does it end in Earth's orbit?


I remain unconvinced that roller-coaster rides to the edge of space
will lead to profitability, and I will remain unconvinced until such
time as it is in operation.

Some very serious people do not agree with you,

And time will prove which of us is right; experts are often wrong.
Similar experts advised clients to pour billions into the dotcom boom,
mag-lev trains, and other such things that never worked out.

Some dotcoms worked very well indeed.

At the sort of price point currently being discussed there
is a substantial market.

No, there is an unsubstantiated claim of a substantial market. The
only proof of a market is when the product starts selling. Until them
it's hopes and dreams. Market research "proved" that "New Coke" would
outsell Old Coke, for example.

http://www.inc.com/magazine/20060301/views-updates.html

Looks like a market to me.

Moreover, the commercialisation of
rocket-based passenger transportation is likely to have the same effect
on that technology as it had for aircraft, that is to lower cost and
cost of entry.

See, it's that "likely" that I disagree with and IMHO has no
foundation. We will see what we will see.

It is likely because it has happened in nearly every other case. Where
there are multiple vendors offering the same or similar product then
prices fall.


Since there is no material substance out in space that is worth going
out to get and bring back at current commodity prices, I remain
unconvinced that there will be profitability in that area either.

This is incorrect. The actual situation is that there is no space
system currently capable of retriving useful quantities of any material
from space whatever the current commodity price. The barrier is
technological, not economic.

Look, let's say that technology comes into being that reduces the cost
of retrieving material from the asteroids to the same as it would take
to drive that distance and back. Even -that- is too expensive, since
we're talking -billions- of miles. So no matter what tech comes down
the pike, unless it's a real paradigme jump beyond what's immediately
reasonable, the asteroids are still not worth the price of going to
get.

We are talking millions of miles, not billions, and there are plenty of
published works on the economics of space mining. It does require
technological advances to make it possible at all, but there is a price
point absent Star Trek technology at which it becomes feasible.


Faith? Let us look at facts: the space sector continues to expand in
both size and importance; space technology continues to improve and is
the subject of considerable ongoing investment; space development is an
area of considerable competition between a broad range of national
governments and commercial interests. All of these facts support a
prediction that the overall capability for exploitation of space will
continue to grow. Prayer is not required.

All of the above is limited to NEO/LEO applications that provide an
immediate service to the customers on Earth and an immediate profit to
the investors.

If the cost to orbit falls significantly then that drastically affects
the cost of doing just about anything else within the inner solar
system, because of the disproportionate deltaV to orbit compared with
travel from orbit to another destination. Orbital space development
very directly affects development potential elsewhere in space.


If any of the things that I doubt will happen do happen, no one will be
happier than I will. I don't mind being wrong, but suggesting that
faith-based beliefs even -might- be false always really upsets the
faithful. The more insults someone hurls, the less secure they are in
their beliefs.

Characterising those that disagree with you as irrational might be
considered less than polite, you know.

Only if you take faith as a perjorative. :) Everything's faith until
it happens. If you plan a wedding it's faith that leads you to assume
your bride/groom will actually show up. If you inevest in a business,
you have faith that it can work out. Others may wel disagree with you.
:)

Faith is a belief held specifically without evidence. There is evidence
in advance for both the appearance of the bride, she said she would for
example, and the appearance of a wider space economy.

.