Re: your mail = Greenhouse

[Kevin C Houston <hous0042@maroon.tc.umn.edu>]

On Sat, 24 Feb 1996, Timothy van der Linden wrote:

> >It isn't that sunlight is stronger or lower in the IR bands, it's that 
> >earth-light is much much loser in the UV and visible bands.
> 
> What do you mean by loser?

Sorry, I meant lower.  the s key and the w key are too close on my 
keyboard :)

> >that is not true.  the _has_ been a temp rise over the last 90-100 
> >years.  It is small, and it cannot be _proven_ to be caused by the 
> >greenhouse gases, but it has occured.
> 
> Indeed, NASA is only one experiment. Ground-based weather data show a clear
> increase. I am interested though why both methods seem to disagree. (CSIRO
> writes in an article that global temperature did increase the last century,
> so it is not just a story from the newspapers and environmentalist)

One theory, is that it is due to the "heat island" effect around urban 
centers.  but this does not seem adequate in talking about records 
gathered in small rural towns (like my home town of Viroqua WI)(5megs of 
nudity pictures if you can find Viroqua on your local map -- No fair 
going to the library) The population of Viroqua is something like 3600, 
and the whole town fits within one square mile.  Heat island effect 
cannot explain the temp rise is such pastoral settings.  But, this does 
not prove the assertion that it is caused by greenhouse gases.

> How convenient, whatever we do, we're gonna die anyway ;)

No, we will just have to find another source of energy, it will either be 
fusion or space-based solar

About the ship:

I have a design outline that I would like everyones comment on:

1) Ship leaves Sol using Maser sail.
2) Ship enters TC using MARS lineac.
3) Exploration of TC and construction of maser array.
4) return module (more on this below) leaves TC using Maser sail.
5) Return Module enters Sol using Maser Sail.

The Lineac Core, large tanks, rotating hab sections, exploration 
equipment, etc.  would all remain in TC system.  only the return module 
and the maser sail would go back.  This should reduce the return module 
mass by a factor of 25 (from 2.5 E9 to 1 E8)Kg 

the return module would be the crews quarters during both acceleration 
phases, the mass should be about 1 E8 Kg (may be too large) during the 
trip to TC, the return module would be tucked inside the rotating hab 
sections.  the Rotating sections, then are freed from the design criteria 
of having to adapt to multiple gravity vectors, the rotating portions are 
designed to rotate only.  This greatly increases the amount of interior 
space available to the TC explorers while in the target system.

imagine a Coca-Cola can with a straw through it along the centerline.  
This would be like the return module with the lineac core.  Then imagine 
the entire assemblage inside a tin can (like for soup)(there would also 
be RM tanks, but ignore that for now)

At TC, the soda can and the straw would be removed from the soup can.  
the soup can would be spun for gravity, and the researchers would live on 
the inside surface.  extra mass from TC asteroids could be added to the 
outside to increase the shielding factor.  Since the soup can would be 
staying behind anyway, it could be designed to be like a colony if 
necessary.  The core would be removed from the Cola can, and the cola can 
would return to earth at the end of the mission.  The maser array could be 
smaller, and regular shuttle flights between the two systems could easily 
be established if it was found to be economical.

the design of the cola can would be very simple, a cylinder about 150 
meters in diameter, as long as you like provided the total mass stays 
about 1 E8 kg.  also the interior 50 meters dia is for the core.  Anyone 
wishing to design living space, here is your target.  At the midway 
point, we coast for a few days (crew time) by firing the lineac at just 
the right strength to cancel the foreward momentum gained by absorbing 
the maser beam.  while we are in this "free fall" state, the cola can is 
removed from the soup can, and put back upside down.  this is mostly 
accomplished with winches and motors.  once the "flipping" manuever is 
finished, the lineac engine revs up and we begin decelerating into TC.
I just realized the core doesn't have to go through the cola can, but I 
am too lazy to correct the previous paragraphs.  And proper design (with 
a pivot point halfway up the cola can) would allow the can to flip quite 
easily. 

During powered phases of the trip, crew would eat stored rations 
10 years of pretty good pre-packed food with 10 years of freeze-dried 
concentrates in case something goes wrong.  

During the exploration phase, the rotating RM tanks (now empty) can be 
used as farm space.  Also, the return module can be repaired because 
nobody is living in it.  If some alien bacteria should get loose on the 
rotating portion of the ship, people can escape to the return module.
People can be left behind in the star system if they are infected, 
without worrying that you are being cruel, because they will have a place 
to live.

I will be putting this on a web page soon, so that you all can see what I 
am talking about.

Kevin Houston