And they won't get there with chemical rockets from the 1960s

http://edition.cnn.com/2006/TECH/spa...eut/index.html

Rich wrote:
http://edition.cnn.com/2006/TECH/spa...eut/index.html


Wonder what amount of the rocket mass would be expended
getting it up to speed...

Richard F.L.R.Snashall wrote:
Rich wrote:

http://edition.cnn.com/2006/TECH/spa...eut/index.html

Wonder what amount of the rocket mass would be expended
getting it up to speed...

Yes. I have to agree that if the human race manages to survive, cooped
up on the one planet Earth, until such time as it can design a
spacecraft using antimatter as its fuel, so as to reach Alpha Centauri
in six years...

then the urgency of expanding into space to ensure human survival is
rather low.

I agree with Dr. Hawking's basic sentiments, however: the survival of
humanity _is_ in jeopardy as long as we remain on one planet, and that
is a reason for establishing communities in space. However, in terms of
meeting *this* need, we will have to make do with Mars colonies or
O'Neill habitats.

This is not to say that going to the stars isn't also a good thing to
do when the time comes. But to have the *ability* to launch a venture
on such a scale, we will first have had to have inhabited the Solar
System!

John Savard

Richard F.L.R.Snashall wrote:
Rich wrote:
http://edition.cnn.com/2006/TECH/spa...eut/index.html


Wonder what amount of the rocket mass would be expended
getting it up to speed...

4000 tons into orbit, no big deal for a REAL spacecraft and almost no
mass expenditure.
But you have to use the RIGHT design.

http://en.wikipedia.org/wiki/Project..._propulsion%29

wrote:

Richard F.L.R.Snashall wrote:
Rich wrote:

http://edition.cnn.com/2006/TECH/spa...eut/index.html

Wonder what amount of the rocket mass would be expended
getting it up to speed...

Yes. I have to agree that if the human race manages to survive, cooped
up on the one planet Earth, until such time as it can design a
spacecraft using antimatter as its fuel, so as to reach Alpha Centauri
in six years...

then the urgency of expanding into space to ensure human survival is
rather low.

I agree with Dr. Hawking's basic sentiments, however: the survival of
humanity _is_ in jeopardy as long as we remain on one planet, and that
is a reason for establishing communities in space. However, in terms of
meeting *this* need, we will have to make do with Mars colonies or
O'Neill habitats.


I assume you read Carl Jastrow eons ago. Confronting the vastness
of space is no simple task. It will require major adjustments hardly
envisioned today. Why send a biological entity when artificial
intelligence can do the job in forms which can cope with space.
klm


This is not to say that going to the stars isn't also a good thing to
do when the time comes. But to have the *ability* to launch a venture
on such a scale, we will first have had to have inhabited the Solar
System!

John Savard