Re: Engineering Newsletter

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

Kevin wishes to interrupt:

> Timothy replies to Kelly:
> 
> >Oh, I still say there is no significant difference between a suicide flight,
> >and a flight where the crew are abandoned with enough supplies to last them
> >their life.  I am frankly shocked that you and Tim could seriously suggest
> >such a horrific and ruthless option.  Thats like sending a team to antartica,
> >on a one way trip to the pole with no resuply and recovery runs!  "Hey guys,
> >go there, explore, radio back what you find, and here's 50 years supplies and
> >parts for you to live out you life with."
> 
> Summarizing what I write in this letter:
> - We have to discuss what is necessary for a small colony.
> - You can't compare Antarctica with a new planet full of life.
> - We (or I) don't see it as dropping people without any regard, but as a well
>   organized lifetime adventure.
> - Do things break down or get lost faster than one can repair or replace them?

Okay, Okay, I think we've all heard enough of this argument.  Neither of 
you is going to change the other's mind.  If all we can do is figure out 
how to send a one-way mission, then I think we can assume that it will 
never be used until someone comes up with a valid reason to send so many 
people off on a no-return mission.  What's a good reason?  Why, one that 
would attract enough qualified (intelectually and psychologically) 
volunteers of course.  I think we all agree that it would be a good 
_idea_ to have a return flight, The question, is whether it is possible 
or not.  i think it is,  A one-way mission would only be sent in the 
direst of planetary emergencies (sun going nova, hostile aliens etc.)

<as an aside, if we knew the sun was going nova, could we use that to 
boost colony (ship/worlds) to other systems?>


> >What electric cars are now, is exotic impractical and dangerous (and oddly
> >not particularly clean).  Fusion fuel can be mined and stored fairly easily.
> > Anti-mater is a nightmare to hold in quantity, and in our case difficult to
> >use efficently.  Again certainly beyond the tech of 2050.
> 
> Yes, but so is 1E18 Watt during a few years. (You would create the same
> energy in a day as the Sun would in a second)

Impractical and expensive, yes, but there are no tech dificulties.  you 
would not be "creating" the energy, but only re-directing a tiny fraction 
of the sun's output.  I would say it thusly "you would be using 1/3600 of 
the suns total output for a period of 2 years" After that, the energy 
could be used right here in Sol System for any other project that was 
desired.

> OK, enough about anti-matter, I hope I've made clear what the advantages are
> if we can use this techniques savely. I accept that 2050 will not be ready
> for anti-matter but I also have strong doubts if any technique can handle
> the high power we need. What I expect to happen in the futere is that
> anti-matter will find its way at the same time that such enormous power
> finds it way.
> 

As to anti-matter and large energy requirements -- I think it would be 
far more useful to figure out how we can send the most mass for the least 
energy.  Tim, if you want to postulate anti-matter, go ahead.  give some 
rough idea of how you intend to make it and store it, and then let us 
argue about when we might expect it.  I for one, will postulate beamed 
energy, and once I have a workable system, I will go about estimating the 
size and manufacturing time of the requesite array.  same with Kelly's 
design, come up with a viable method of stopping and tell us how long it 
would take to come up with the tech. (or lhow long it will take to 
pre-load the decell track) Then when we have several methods, 
we can rank them according to speed of travel, tech level, and other 
factors, to come up with a viable method.  

Tim, i have a question for you regarding anti-matter,  how do you intend 
to direct the "exhaust"?  as I see it, anti-hydrogen would combine with 
normal hydrogen (scooped?) and this would result in a burst of Gamma rays 
in _all_ directions.  how will you harness the momentum of these photons?
assuming you can make and store the anti-hydrogen, how many Kg of 
anti-matter would you need to get to the target star?  do we carry the 
return trip fuel with us? or try to make it from the target? if we are 
going to make it, what percentage of energy can be turned into 
anti-matter? (and you can't assum 100% eff. either, or then I can assume 
100% eff. solar arrays and microwave converters ;) ) and where does the 
energy come from if you intend to make it?

(one idea for storage of anti-matter, start with anti-hydrogen,made from 
slamming high-speed protons into a stationary target, and use fusion to work 
your way up to anti-iron  does anti-matter give energy when it fuses 
with anti matter? i think it must. when you have a quantity of anti-iron, 
magnetize it and your storage problems are solved.  many of these 
technologies probably won't be avail until 2250 AD  :(  )

> 
> I'm not sure I know what Kansas is like, but surely if they had some
> habitation-modules from the year 2050 they could prosper.
> The modules have a self sustained climate, their only input is energy (from
> a small anti-matter-tank :) or just plain old solar-panels). Not only its
> climate is self-sustained but also vegetables and other food would would be
> grown. So now that you have your first-aid life support for one or two
> persons in say 300 cubic metres, you want something to do. OK in Kansas you
> probably could do nothing at all, but on TC you might want to get out. So
                 ^^^^^^^^^^^^^^^^^
I thought you said you didn't know what Kansas was like.  ;)
(for information, it is totally flat, totally farming, and totally boring)

<big snip, different subject>

> That may indeed be the case, but a 10 year exploration with 100 people is
> hardly enough to do any real research of a complete solarsystem. Not to
> mention refueling or building complete beaming-arrays (only advanced
> nano-tech or anti-matter might overcome that problem).
> 

One of the implicit assumptions I'm going to use is that some form of 
self-replicating machinery is possible.  not nano-tech, and not 
self-directed either.  I'm assuming that a robot can be made that can 
make a copy of itself given: premade circuit board (pentium level 
motherboard with cameras and wireless modems) and ready made ores.  that is, 
some other machine refines the ores and gives our robot "ingots" of 
aluminum or silicon or whatever else it needs.  
The robot needs to do the following autonomuos tasks:

1) shape metal into any shape (most NC millers can do this today)
2) make a 1 meter by 1 meter solar cell from a solid ingot of silicon and 
proper doping materials (they work in vacumn, so much bulky equipment 
won't be needed
3) scoop or mine ore and bring it to a central location
4) wind motors, connect wires and other tasks required to make a copy of 
itself (note, while theoretically, one robot could make a copy of itself, 
in pactice, many would be assigned the task of turning out more robots

A Semi-autonomous computer would direct all the robots, while humans would 
be available for debugging, and initial set-up.

an ore processing machine will be required as well as constant oversight 
by one or more crew.

these would then be able to first, turn out many copies of themselves, 
and then secondly, they could begin turning out the hectares of solar 
panels needed for the maser transmitters. the same system would work in 
Sol, as would work in TC 

This would solve the problem of super-large collecting arrays, by 
allowing geometric growth of the machinery needed to manufacture it.

Kevin 

who _makes_ glass beads, but doesn't brag about it in off topic groups ;)
just kidding Ric.