RE: Engineering Newsletter

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

To: All
Re: various.

Bio interaction between earth and E.T. organisms.  

first, I believe that any viral infection is not possible, due to the 
totally arbitrary rna to protien coding system that earth biology uses.

Of course all this assumes that the ET biology uses DNA/RNA Glucose ATP 
systems, but i do have sound Therodynamic/chemical reasons for thinking 
this is the case.

bacteria/fungi on the other hand may pose a serious threat suposing that 
our systems are even remotely similar, I think it will come down to how 
long that particular ecosystem has been evolving.  if it has been a hort 
while, then i think that or immune responeses will likely have seen a 
particular attack statagy before, and will know what to do.  if the ET 
biology has been around longer than us, then I suspect that we will be 
more vulnerable.

however, many earthly bacteria exploit specific weaknesses in our 
defenses in order to enter our systems.  Alien bacteria would not be 
designed for this.  Also, our immune system would probably go into 
hyperdrive if it was presented with a truely alien protein.

I believe that Kelly is right when he identifies allergic reactions as 
one of the main health problems to be faced.  

This doesn't even consider what a nasty little fungus like yeast 
(deposited on the ground the first time you tried to spit out the foul 
smelling pollen that was making your throat squeeze shut) would do to an 
alien ecosytem.  you might think it's kinda cute the way they take sugar 
and make alcohol, but I'll bet that just about every other biosystem we 
ever encounter will think that it's a vile poison. and won't have any 
idea that making penicillin would get rid of it.

this is not to say that a alien ecosystem would be totally useless to 
us.  who know what wonders we may find.  how bout an organism that can 
"grow" silicon chips?  of solar cells?  perhaps some organism lives in a 
metal rich environment and can really concentrate metal ores.  Perhaps, 
perhaps, perhaps.  I could go on all day, how bout a critter that _likes_ 
70 % ethanol (I'll bet that many companies would love to make brandy 
without having to distill) bacteria that excrete oil, or plastic, or ones 
that prefer it as a food source.  the list goes on and on, and I'm very 
willing to bet that none of these creatures will be the first exploitable 
alien lifeform.  and I'd further bet that the universe is not only 
stranger than I imagined, it's stranger than i _can_ imagine.

In short, A totally barren 1 G planent would be ideal for colonization, 
but totally boring for study.  

To: all
Re: mission

Ok, I think we all have come slam up against a brick wall.  Sending
1 E+09 Kg _any_ distance and coming back to rest WRT the target system 
is turning into a Herculean task.

The charter says that we have remote sensing clues of a biosphere.  we 
also have a public mandate for sending some people there to study it.

I think perhaps it's time to either put the "Asimov" on a diet, or 
approach the problem from the other end.  To put the "Asimov" on a diet, 
I'd suggest at least a thousand fold reduction in payload down to 1E+05 Kg
I think this rules out self sustained mission, and requires a return.  I 
still think we can go at 1 G, and use a MARS for the engine, but in order 
to over come the photon thrust, we're going to have to bring more 
reaction mass ( and use a slower exhaust velocity).  for the return trip, 
I'd suggest scrapping the lineac entirely, and relying on photonic thrust 
for both portions of the trip.  this means that some payload capacity 
will have to be devoted to maser transmitter control packages, but i 
don't see this as a real problem.  the crew should be pared down to no 
more than 100 people, and the return module can totaly scrap the hab ring 
which can then be left in the target system as a stepping stone for a 
follow up crew if one is deemed desirable
I'll follow this up with some hard numbers later,But, one thing that 
strikes me off hand is this, for reflection, p= 2E/C  this is great for 
acelerating.  for absorbtion, p=E/C this is a smaller amount of photonic 
thrust to overcome. so for example, a energy beam that provides 10 m/s^2 
acceleration via light pressure only needs a 15 m/s^s deceleration from 
the engines to equal 10 m/s^2 total. and if it takes a 1000 to 1 RM to 
payload ratio, then that is the cost. and we just have to live with it.  
but once you get 100 people and a number of maser arrays in orbit around 
another star system, then sending a follow up mission is relatively easy 

the second option is to design this mission as if we had _no_ long range 
information on nearby systems, and design a small ~ 5000 Kg robot. to 
explore nearby systems, and return pictures and other information about 
every system in a 20 ly. radius.  we might not have to slow down entirely,
a .5 C flyby might work here.  and perhaps a magnetic turning might 
work for some long range steering.  The robots should be small and 
low-cost, so that is we lose a few, it's no biggie.  then to luanch, we 
could use a particle luancher, (just like a solar sail, but you use 
charged particles and a heavier acceleration factor) and once the probes 
are up to speed, we don't bother with them again.  

well, my connection is getting slow, so I'll send this and wait til I get 
home to send the rest.
Kevin