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Re: starship-design: One way (again...)

> From: Kelly St <KellySt@aol.com>
> In a message dated 12/8/97 3:24:52 PM, you wrote:
> >From: Kelly St <KellySt@aol.com>
> >> 
> >> Then don't go by train. Most of our systems could get their once and 
> >> back easier and cheaper then going their and seting up infastructure.
> >> 
> >That is debatable.
> >
> >My opinion is that it would be cheaper to go one-way to establish
> >infrastructure (as I have written before the biggest problem as for now
> >is the propulsion - certainly going one-way halves this problem).
> I disagree strongly. A construction expidition or a long duration mission
> would need to be far better equiped, and far larger.  Hence, both would be
> more expensive.
Due to the distances, the time duration of the two types of mission,
when taking into account Isaac's calculations
that most probably due to technologially affordable mass ratios, 
the cruise speed for the two-way mission would have to be halved:
    flight there (10 yrs);
  + sustained stay for the rest of the crew (natural) life
    (with life expectancy in space of 70 yrs, age at start 30yrs,
     and flight time 10 yrs, this phase will last 30yrs at most);
  = 40 yrs;
    flight there (20 yrs);
  + sustained stay for the exploration phase (5 yrs);
  + flight back (20 yrs);
  = 45 yrs.
may actually be in favor of the one-way mission.
Not speaking about the fact that those who return from
the two-way mission will land on Earth five years
after their life expectancy...

Hence, the two-way mission will need approximately the same
amount (and duration needs) of the equipment.
But two-way will be much more demanding from the fuel/engine
point of view (as Isaac correctly remarked, not simply two times
more, but possibly orders of magnitude more).

Hence, which would cost more - still REMAINS DEBATABLE.

Note also that in order to not became a suicide mission,
the two-way mission plan must ALSO be capable to safely change it
into one-way at target when the return flight becomes impossible
for some quite probable reasons (engine failure, problems
with fuel mining at target, etc.).

> >Especially in long run: two-way leaves practically nothing
> >over there to go back for; establishing an outpost - well,
> >establishes a target to return to (at least to help with new
> >supplies them struggling over there...).
> >
> >Remember Apollo - a plant-the-flag mission has little consequences
> >and does not lead to sustained exploration. 
> >The Russian "Mir", being a true outpost in near-space
> >is since many years the only long-term space project -
> >one of its main effects being prevention of Russian space program
> >from a total collapse... 
> >The two-way mission "just to show it is possible" will also make 
> >a much less impact and consequence than the outpost-building.
> No, we would not go somewhere just to go to an outpost. In itself, 
> an outpost isn't a goal or a reason for going somewhere. 
> At best its a tool to allow you to do something there.  
> At worst its a stunt.  (Been there, done that, took
> our bows, and went home.)  
Ahh, but the above applies even stronger to the two-way mission
(especially the "and went home" part ;-)).
Hence, from this point of view one-way and two-way seem equivalent...

> If your assuming a maned outpost, it would be a strong incentive to cancel
> the first mission.  I.E. to prevent being forced to eather: 
> send a retriaval expidition to bring them back, or to take the heat
> for leaving them to die for some Apollo like stunt.
>     ^^^^^^^^^^^^^^^^^^^
You again with that "leaving them to die" rhetoric...
And "leaving them to die" back on Earth is so much better?
Or "leaving them to die" during the long and quite boring 
return flight (of old age/sickness or in a catastrophic accident,
much more probable during the return flight due to engine wear)?

> >And, Kelly, you seem to contradict yourself at the costs issue -
> >in another post you have written:
> >
> >> From: Kelly St <KellySt@aol.com>
> >> Date: Sun, 7 Dec 1997 10:59:57 EST
> >> [...]
> >> Thats effectivly a suicide mission.  I know a few folks in this group
> >> disagree, or don't care, but it still would meen no government on earth 
> >> could get permision for such a mission.  
> >> I.E. your throwing away a crew for no critical reason.
> >> Specifically your doing it to save money,
> >> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
> >> which is really not going to sell.
> >> 
> >I.e., you assume (and use it as an argument!) 
> >that one-way will save money... Voila!
> I thought you had used that as an argument!? Why else would you not 
> equip an expidition with a return capability? I thought your whole 
> suggestion for this started as a suggestion to save money?
You suggested that one-way will be much more costly (due to much 
larger needs for long duration supplies, repair factories, etc.).
I had only countered your opinion on that, arguing that
the costs might actually be smaller for one-way.
My main arguments in favor for one-way were (and are):
- technological feasibility;
- safety.
Cost is for me a secondary factor here, but, in my opinion,
ALSO in favor of one-way.

> >> >> Seariously a big question we've never gotten very far with is why 
> >> >> anyone would send such a mission?
> >> >
> >> >See, above. I still haven't found a sound reason to send any mission.
> >> >Lee
> >> 
> >> Me neiather.
> >> Kelly
> >> 
> >Yes, in short term, there isn't any.
> >But remember Sagan: 
> >"All civilizations become either spacefaring or extinct."
> Tese missions would in no way make us a more 'spacefaring civilization'.  
> They would however require us to already be a very space faring  
> civilization to launch them.
Yes, before undertaking an insterstellar mission we must be
already a very spacefaring civilization - in fact I have repeated
this several times in our discussions in the past (and in the next
paragraph of my previous letter too, see below).
However, going interstellar will be the logical and ncessary
NEXT step to become really spacefaring, not merely in-system-faring...
We all agree that interstellar travel is orders of magnitude
harder than in-system, hence being able to launch a starship
will certainly signify that we are much more spacefaring
than before.

> >Of course, we must first settle our system to a significant
> >degree (at least to be able to built a HUGE starship
> >without hauling all that mass from Earth's gravity well).
> >
> >Thus, barring some great breakthrough like FTL,
> >I do not see any real possibility (if not technological,
> >then psycho-/econo-/political) to send a manned interstellar
> >mission within 50 years or so.
On the abvoe we agree, I presume? ;-0

> >Returning to Sagan, his prediction already seems to turn
> >the dangerous way - as Kyle has remarked:
> >
> >> From: "Kyle R. Mcallister" <stk@sunherald.infi.net>
> >>  
> >> The visionaries of our world are nearly gone. What I mean by this is  
> >> the ones that saw true worth in our exploration and expansion,  
> >> those such as Carl Sagan, Isaac Asimov, and the like are all dying. 
> >> The sad thing is, there seem to be few if any new visionaries 
> >> like them. I, being a teenager, spend considerable 
> >> time with other teenagers, and can tell you that the vision is gone. 
> >> Arthur C. Clarke and Rober Bussard won't be around forever. 
> >> I just wonder where the human in humanity has gone.
> >> 
> >Without opening a real big frontier in space, the humanity will
> >decline even faster and earlier than we may expect.
> >The symptoms are already quite visible.
> I'm not sure what your talking about as symptoms, 
One example - a prominent member of the interstellar travel
discussion list so strongly opposed to even considering 
one-way missions as a discussion option!    ;-(

> but their are plenty of
> other visionaries. Many working to build more realistic and grand visions.
> But they aren't as interesting to the public at the moment.
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
You just pointed out another symptom...

> Personally I think interest in space will perk up when space does do things.
> At the moments its effects have been quite underwelming given the levels of
> effort.  A more productive space program, should gain more interest and
> approval.
Possibly, let us hope so.
But without a vision and exploration spirit in plenty,
there will be NO "more productive space program",
or even any space program.


-- Zenon