[ RadSafe ] Mission to Mars

[JPreisig at aol.com]

Howdy Radsafers:
 
     This is from:    _jpreisig at aol.com_ (mailto:jpreisig at aol.com)    .
 
 
     Guess I've been thinking more about a space  mission to Mars with 
Enriched fission (Uranium or
whatever) propulsion.  I guess my earlier e-mails indicated a one-way  Mars 
travel time of 3 years,
which was reduced to 1.5 years using not so enriched uranium.  This  was 
based on calculations 
seen in the article by Dicke in Maglich's Adventures in Experimental  
Physics.  Further crude
calculations on my part indicate (using 100% enriched U235 Uranium) that  
the one way travel time
to Mars (compared to 1% U235 in natural Uranium) would give a travel time  
of about 2 months.
If the original not so enriched uranium was 5% U235, then the travel time  
one way would be about 
4 months.  This is not so bad.
 
     A mission to Mars would take 2 months each  way with 2 weeks for 
taking samples and doing studies
on Mars, thus resulting in a total trip time of about 4.5 months or a bit  
longer if the one way
travel time is 4 months.  If one could actually do this in the USA or  
wherever, then maybe one of us
health physics types could also make the trip SOON???
 
     Guess what's going on in Japan will limit what the  public will 
tolerate with such a flight project
in the near future.
 
     Hope the health physicists and that geologist are  doing OK out there 
in Los Alamos, with all the fires
going on.
 
     The nuclear reactor problems in Japan are causing  significant amounts 
of farmland from
being removed from growing food.  This is not a good thing.  Ways  must be 
found to remediate
such farmland economically.
 
     I guess that other geologist and some of you other  folks were talking 
about loss of life from
natural phenomena and industrial accidents and the like.  Mention  
earthquakes again, why
don't you??? In Tang
shan, China in 1976, a fairly large earthquake (7.6???) killed  250,000
people in the time span of hours to days.  The 250,000 number is  
supposedly an underestimate
with 500,000 deaths being a possibility.  Eyewitnesses from France  staying 
in the Tangshan area
at that time, saw that the city was obliterated with considerable loss of  
life.
Earlier earthquakes in China actually killed more people than this.   See 
Bruce Bolt's book on
Earthquakes for some other loss of life information.  Tornadoes,  
hurricanes etc. seem to not be on
the same scale in terms of loss of life.
 
      Don't think a USA spaceship can take off  moving directly vertically 
upwards from the ground?
Watch a Harrier aircraft or the US version take off from a ship at  sea.  
Pretty cool, huh???
Harriers are old technology.  Think of what improvements could have  been 
made via USA
engineers and scientists in the last 40 years.  Envision perhaps a  
spacecraft with 4 or more
GE Jet airplane engines strapped to the sides of the spacecraft  and else 
where.  And at this point, that
comedian Tim Allen would suggest that his version of such an aircraft  
would need even more
lifting power.
 
      Three fairly major nuclear problems  have occurred in 30 years.  
Chernobyl had limited
containment, along with some fairly poor human errors occuring.   Japan's 
reactor did well during the
Tsunami, held containment and then had problems with hydrogen buildup,  
right???
Thank goodness for Three Mile Island.  Containment worked well, even  with 
some uncovering of
the core.
 
      I heard from my MS advisor, or someone else  at that time, that that 
reactor accident where
the one worker was pinned to the ceiling via the control rod, was actually  
caused by one fellow
goosing the other (pinching him in the hindquarters???).  I also heard  
there were some social 
problems among the 3 workers involving someone's marital or girlfriend  
partner.  Guess the people
there at the time know best what happened.
 
     Nothing says we have to use nuclear power.   Apparently the Marcellus 
natural gas deposits in
New York, Pennsylvania etc are quite sizeable.
 
     I like the idea of reactors making  power.  Unfortunately mother 
nature is still a Bi_ch sometimes,
and humans sometimes make mistakes, even with well engineered  systems.
Wish fusion would work well soon.
 
     Hope you are safe where you are (and from the  Movie the Marathon Man 
--- Is It Safe????)
 
     Regards,    Joseph R. (Joe)  Preisig, PhD