SETI again

IMHO, in 100 years the an attempt to settle another star would have a
fairly good chance. they would have to have a lot of redundances,
including multiple ships, on slightly different paths. also they
would have to plan on losing 90 percent or more of their resourses
along the way, yet still have the resourses to maintain their life
for sometime after reaching the star. In addition, i dont think any
attempt would be made to send a colony out, unless there was enough
data about the star before they left to know that it had a fair
chance.

--- In spacesettlers@yahoogroups.com, Douglas May wrote:
>
> On Jul 27, 2006, at 3:39 PM, Lucio de Souza Coelho wrote:
>
> > I would take buildings out of the examples. There are buildings
with
> > concrete of even steel structure that are holding up perfectly for
> > over a hundred years. And there are stone cathedrals from the
Middle
> > Ages that are over a thousand years old. And this without
structural
> > need of major overhauls.
> >
> > In fact, the longevity of buildings, particularly the ones made of
> > concrete and stone, are the main argument in favor of space
colonies
> > made of concrete or perhaps some synthetic stone (like cast
basalt).
>
> Yes, buildings aren't as good an example. The structures of older
> buildings do last longer, but the infrastructure of modern
buildings
> (I.E. plumbing, wiring, communications, elevators, etc) still
becomes
> increasingly inadequate and eventually wears out. But even the
older
> buildings eventually crumble. Only the pyramids remain of the 7
> ancient wonders. Earthquakes, volcanoes, and wars will (hopefully)
> not affect the settlements, but there will be other perils. We
don't
> really know what kind of damage to expect on the structure of the
> settlements from radiation. The radiation shield will last a long
> time, but solar panels and other weak points may experience
trouble
> after a few decades. We don't know how dense the meteor material
is
> in interstellar space. The Oort cloud is full of dust and rocks.
> Major collisions would be very rare, but smaller ones could be
> common. The accumulation of years of sand sized meteors striking
the
> settlement while the settlement is traveling several million miles
> per hour would certainly cause wear and tear on certain parts of
the
> craft.
>
> A big problem with attempting interstellar repairs on a settlement:
>
> If a comet/asteroid/brown dwarf or whatever were needed for
material
> to repair a settlement, as far as we know right now, we would have
to
> change course and slow down to get it. To slow down in deep space
> somewhere between here and another star would require a lot of
time
> and energy. Reaccelerating would also require time and energy. A
star
> faring civ would likely have both time and energy available, but
> neither would be unlimited. A journey to say Alpha Centauri of 50
> years could be extended to 100 years or more if we had to stop for
> repairs. Kind of a bummer for those who hoped to see another star
> before they died. Also that could mess up our planning on how long
> our recycling program can run before certain items run out.
>
> Reliable, long lasting electronics are a must for interstellar
> travel. Also, we should probably get pretty good at making
electronic
> and mechanical components out of a variety of different materials,
> just in case we can't find the normal elements at a critical time
> when repairs are needed and supplies are low. Manufacturing
chemical
> elements is probably not going to be an option for an early type I
> Civ (at least for an isolated, brokedown settlement), since the
> amount of energy required to fuse mid-size atoms requires
something
> with the energy of a supernova.
>
> Basically, my point is just that I believe we are still a long way
> off from being able to consider star travel. If we launched a
mission
> 100 years from now, I doubt it could survive. I have no idea how
long
> it will be before we are ready, but it will require new
construction