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Re: RE: starship-design: Interstellar mission within fifty years

In a message dated 10/9/98 11:59:39 AM, zkulpa@zmit1.ippt.gov.pl wrote:

>> From: "L. Parker" <lparker@cacaphony.net>
>> > As far as I know, still only on paper.
>> > Did they produced some rocket exhaust generated by
>> > actual fusion reaction?
>> No, this is an engineering study. JPL has tested the reactions 
>> and verified the energy output. 
>Actually maintaining a sustained fusion reaction with positive energy
>balance? It would be quite a media event, such an experiment!

It wasn't sustained, and didn't actually interest the media much.  Pulse laser
fusion systems with positive energy balence got only short mention on tv in
the '80's eaither.

>> In other words, the technology has been proven - the
>> actual engine has not been built. But it is far from being only on paper.
>> > 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?
>> The production of antimatter is currently very low, however, ICAN and
>> AIMSTAR do not need much, the amounts are well within what we expect to be
>> able to produce within the next twenty years.
>But we are discussing needs of an interstellar flight,
>not a single ICAN spacecraft.
>> Storage technology is hard science, already built, and tested 
>The current containers can store only picograms or even less
>of antiprotons, have an astronomical mass ratio (container/antimatter),
>and can store the antiprotons only for few days
>(they slowly annihilate inside...).
>Scaling it up to tons of antimatter stored for tens of years 
>without loss will need quite a breaktrough in storage methods
>and technology.

Here we agree!

>> (they drove around the U.S. with the
>> storage container loaded with antimatter in the back, we're still here so I
>> guess it worked.)
>That's news. As far as I know, they said that some time 
>it will be possible... 
>Did they already get proper permits to haul antimatter 
>on U.S. highways? I doubt that.

Well there obviously no law against it, so they wouldn't need permits.  I know
we ship Anti from CERN to US accelerators every once in a while too.

>> > I doubt seriously if we discover a habitable planet
>> > around another star. Kelly seems right here - it will
>> > be either inhabitable, or deadly.
>> The only way to find out is to go. 
>Exactly. Almost.
>I questioned that we may discover "a habitable planet" from Earth.
>I am in no way against going to find out.
>> Besides, I am not a fan of settling other planets, 
>> I think we should start by settling the system, planets are for
>> sheep...and sheep herders.
>Yes and no. I think it will be easier to settle a planet 
>(in the sense of building a permanent, self-sutained habitat 
>for a significant number of people), that building equivalent 
>artificial colony in space, at least in a foreseable future.

Big disagree.  In space building a O'Niel is probably easier then landing and
building the infastructure for a similar sized city.  In space your not cut
off from resources and free power, and transport and lift costs are about nil.

>> > 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.
>> Perhaps not, I was merely paraphrasing someone else. It was either Marc
>> Millis or Carl Sagan, either way, they certainly know more than I.
>I do not question your knowledge (nor theirs).
>However, I doubt if public will be so excited by finding
>a "habitable" planet around another star.
>At least not in these times - the presence of such a planet 
>will change nothing in our life and our abilities to go there
>within the life of this generation.


>It will be another thing if the possibility of living outside
>Earth by a significant number of people for all (or most)
>of their lives becomes a common fact. Then finding a similarly
>habitable planet around another star may stir some public
>interest, not earlier.

Might be a big thing to the spacer, but to the Earth developed pop it will be
a noventy.  But not a big event.

>I see that I must add a proper disclaimer:
>I am not such a die-hard pessimist, as some of you seem to think.
>My point is that quite a lot of hard problems still remains unsolved
>and needs much work to solve. Hence I think that easy optimism that 
>all is already essentially in place (as expressed in some posts lately) 
>may be quite unreasonable, generating too much self-confidence
>where a call to arms seems more appropriate.
>-- Zenon