RE: starship-design: Interstellar mission within fifty years

[Zenon Kulpa <zkulpa@zmit1.ippt.gov.pl>]

> From: "L. Parker" <lparker@cacaphony.net>
> 
> > Ad. 1: Propulsion
> > -----------------
> > I think it will not be possible, unless some real breakthrough
> > occurs in one or more propulsion system ideas that seem feasible
> > from our perspective, namely:
> > - fusion rocket;
> 
> First generation under test at JPL
> 
As far as I know, still only on paper.
Did they produced some rocket exhaust generated by 
actual fusion reaction?

> > - giant lasers (possibly solar-powered);
> > - antimatter rocket (including an efficient antimatter factory).
> 
> First generation under test at JPL
> 
Ditto.
And what about the antimatter factory?
Current annual production is able to deliver a kilogram of antimatter
in several million years, counting optimistically...
And what about reliable containers capable to hold tons of antimatter
for years on?

> > I mean, unless the real working design will be proposed,
> > a prototype build and tested in space.
> 
> VASIMR is scheduled to FLY in 2005. While not exactly a fusion rocket, 
> it is close in terms of performance...
> 
We will see... I am rather skeptical, especially concerning
the performance.


> > Ad. 2: Infrastructure
> > ---------------------
> > I do not think it at all possible to build a starship without
> > extensive infrastructure in space, including asteroid mines
> > and space factories.
> 
> True, but...
> 
> > It must of course start from building
> > permanent human habitats in space and on other planets/moons.
> 
> Not necessarily, these _could_ be automated or even teleoperated in some
> cases. But admittedly, we would vastly prefer a human presence for our own
> reasons <G>.
> 
First, actual complex mines and factories cannot yet be fully
automated without human supervision, and will not without
real breakthroughs in AI and nanotechnology.
Teleoperation is also infeasible for interplanetary distances
(remember Sojourner...), even on the Moon 
(ask Russian drivers of Lunokhods...).
Second, our starship should be a viable "permanent human 
habitat in space", and rather large for that.
How to build one without any prior experience?
Do you think that the very first human space habitat will be 
that going to another star?


> > Also, the progress in this area is excruciatingly slow -
> > it is even more annoying than the slow progress in point (1) above,
> > as the progress in this area already needs no essential breakthroughs
> > in science or technology, only the will and money.
> 
> Umm, I would submit that it is more a matter of acquiring a historical tech
> base of what works and what doesn't, which only happens in direct relation
> to how much time we spend doing things in space to acquire this knowledge.
> Sort of pulling ourselves up by our own bootstraps. It will get better as 
> we go along, probably a LOT better.
> 
True, but we should START going in the first place.
Apollo seemed such a start - but after that first step,
we made two steps back.
With current attitudes, it is not going, but crawling,
and not always ahead.
Say, Pathfinder was a nice toy, but no number of Pathfinders
will build the necessary space infrastructure.
So naming it a "Sagan Station" sounds rather denigrating 
(for Sagan).

> > Summing up, if something does not, rather dramatically,
> > change the attitudes and goals of humanity concerning space,
> > the probability of launching a starship within fifty years
> > is very, very low.
> 
> Well, there is that. Of course, as has already been said elsewhere (Warp
> Drive When?) if we discover a habitable planet around another star, the
> public will want to know why we haven't _already_ invented a warp drive!
>
I doubt seriously if we discover a habitable planet
around another star. Kelly seems right here - it will
be either inhabitable, or deadly.
Moreover, so what? I do not think the public will care much,
unless general attitudes toward space exploration change significantly.
Hence I also consider SETI to be currently more of a distraction
than help.


> Your club is a good start, 
>
Thank you.
Americans have such clubs aplenty and are certainly the foremost
spacefaring nation in today's world. Most other nations are
in deep freeze here (except, possibly, Japanese), 
but including most Europeans, despite ESA. 
Our humble attempt is to rouse some interest in space exploration, 
mostly among Poles. We are also involved in organizing
the Polish Chapter of Mars Society.
We will see if it produces any effects on this side 
of the Big Puddle.


> there are also other avenues that help. 
> ANYTHING that encourages the commercial use of space should be helped along.
> Commercialization of space will result in the fastest overall growth path.
> 
Here I fully agree. 

-- Zenon Kulpa

* * *  URANOS: Club for Expansion of Civilization into Space  * * *
http://www.uranos.eu.org/uranose.html          uranos@uranos.eu.org
All civilizations become either spacefaring or extinct [Carl Sagan]