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

[kuo@bit.csc.lsu.edu (Isaac Kuo)]

KellySt@aol.com wrote:
>In a message dated 12/4/97 3:09:55 PM, kuo@bit.csc.lsu.edu wrote:

>>>>> I disagree.  If I were offered the chance to fly on a 1 way mission
>>>>> to the Alpha Centauri systems at .2c (where I'd then spend the rest
>>>>> of my life), I for one would jump at it. I'm sure there are many
>>>>> others who'd be just as excited to do so.

>>It's not a suicide mission.  Suicide is purposefully dying prematurely.
>>With a couple hundred years of life support supplies, there's no
>>inherent reason why the crew would die prematurely.

>Actually even if you had a couple hundred years of suplies its unlikely the
>ship could stay functional for more then a few decades.

Even if that were the case, it's not _certain_ to fail.  At least
in American culture, this is a critical difference.  It's why we
were willing to enlist in 2 dozen bombing mission tours but never
even considered Kamikaze missions.

>Normal systems on that scale usually burn out after 40-50 years.
>Given the lack of replacement parts (stored parts also don't last
>forever),

They don't have to last forever.  They just have to last several
decades.

>and the fact the crew would also be wearing out

Why would the crew be wearing out?  We'd be getting old after a
while, but at that point it would be getting less and less
important to have the equipment last much longer.

>(thus lowering their ability toservice the craft), the ship
>probably wouldn't last as long as the crew theoretically could.  Humm.. then
>again the crew isn't going to have access to top of the line medical
>facilities (or non aging medical personel) so their life expectancy would be
>shortened too.

The life expectancy would indeed be greatly reduced compared to
staying at home.  Besides the lack of medical facilities, there's
the issue of improvements in technology back at home.

The worst case possibility is if someone develops a "fountain of youth
pill", which can be manufactured on the ship.  Then the crew would
be guaranteed to die due to lack of supplies and/or ship failure.

But none of this is _guaranteed_.  So it's not a suicide mission.

>>As for 2-way vs. 1-way, I gave as an example a .2c cruise speed.
>>A 2-way mission at .1c would take at least 80 years to get there
>>and back!  With current human lifespans, that sounds to me a
>>hell of a lot worse than going one way in 20 years and then spending
>>the next half century or so basking in the warmth of alien suns.

>I don't follow the numbers.  First you state a .2c cruse speed vs a .1.  Why
>would a 2 way mission use a slower ship?

Because a 1 way mission can go at 1/2 delta-v of a rocket, while a
2 way mission can only go at 1/4 delta-v.  Alternatively, if beams
are used for the acceleration run (and the deceleration run of the
return journey), the 1 way mission can go at 100% delta-v, while
the 2 way mission can only go at 50% delta-v.

>Oh, and since your stuck in the same ship parked there, or on the flight back
>(no you can't spend you years on an alien beach), I can't see how parked would
>be prefereable.

Alpha Centauri includes a binary system.  It would indeed take decades
to study this system, which is very different from our own.  Being
on site means being able to rig up whatever equipment is needed to
make whatever observations are desired (a 2 way mission could leave
behind unmanned probes, but they'd have more limited capabilities and
wouldn't be able to react to scientific advances prompting new
observations as quickly).

Stars aren't just big balls of fire.  Even studying our own Sun is
a lifetime career!
-- 
    _____     Isaac Kuo kuo@bit.csc.lsu.edu http://www.csc.lsu.edu/~kuo
 __|_)o(_|__
/___________\ "Mari-san...  Yokatta...
\=\)-----(/=/  ...Yokatta go-buji de..." - Karigari Hiroshi