Fw: Re: [ RadSafe ] [RadSafe]Mission to Mars---Fission Propulsion

Jerry Lahti jerry1018 at wowway.com
Tue Sep 30 10:42:31 CDT 2008

---------- Forwarded Message -----------
From: "Jerry Lahti" <jerry1018 at wowway.com>
To: JPreisig at aol.com
Sent: Mon, 29 Sep 2008 17:38:27 -0500
Subject: Re: [ RadSafe ] [RadSafe]Mission to Mars---Fission Propulsion

Joe, nothing is really new here.

Back in the 1963-1973 era, I was with NASA-Lewis Research Center (Cleveland 
OH, now John Glenn Center) and was involved in many aspects of nuclear power 
for power and propulsion in space. A propulsion fission reactor system, 
Nerva, was developed (and built and tested by Westinghouse)for a proposed 
manned Mars mission.  A higher power version, Phoebe, was being designed by 
LASL. The reactor was NOT to be used to escape from the earth's surface, but 
used for interplanetry propulsion.

For more details and an interesting summary, see the "Proceedings of the 
National Symposium on Natural and Manmade Radiation in Space" held March 1-5, 
1971. The specific reference for the proceedings is NASA-TM X-2440, Jan 1972, 
1020 pages. This document summarized many aspects of nuclear power in space 
just prior to cancellation of virtually all of these programs. In particular, 
yours truly contributed a paper regarding radiation doses duse to solar 
flares on a typical Mars mission.

It's interesting to see that this subject is being revisited.

Jerry Lahti
Naperville IL

---------- Original Message -----------
From: JPreisig at aol.com
To: radsafe at radlab.nl
Sent: Mon, 29 Sep 2008 17:16:49 EDT
Subject: [ RadSafe ] [RadSafe]Mission to Mars---Fission Propulsion

> Dear Radsafe:
>      This is from:    jpreisig at aol.com    .
>      Hello Again Radsafers:
>      Hope you all are well today and don't require a US Federal Bailout....
>           I've been thinking about space travel to Mars again using fission
>      propulsion.  I refer you to several articles by Freeman Dyson 
> in the beta     volume of the book "Adventures in Experimental 
> Physics" --- Bogdan      Maglich, editor.  I hope you can find it in 
> your library.  In one of the articles     Dyson indicates that one 
> can use fission propulsion (without resorting to     bomb propelled 
> rockets> to achieve exhaust velocities that are twice as     large 
> as the velocities that can be reached via chemical propulsion.  
> >From this,
>      I infer that a readily achieveable fission propelled rocket can 
> ultimately be 
>      designed which can go twice as fast as chemically propelled 
> rockets (at     least>.  This would reduce the round trip time to 
> Mars from 3 years to      about 1.5 years.  This is helpful if one 
> is living in a spaceship for such a     long time.  Further 
> additional techniques used to reduce the total travel      time to 
> Mars would also be desirable.
>           So, considering use of Uranium to power such a trip, how 
> could such     trip be safely made?  For takeoff, the fission 
> reactor propelling the rocket
>      (or whatever> would largely contain Uranium (and not so much Cesium
>      or Strontium which are produced via fission>.  So, let's assume 
> a safe     launch can be made.
>           The rocket and astronauts (hopefully not 
> Chimpanzees???!!!> would     fly to Mars, land on the planet's 
> surface, and do whatever science and other     tasks which need to 
> be done.  If necessary, a chemically propelled      lunar/Mars type 
> lander could be used to get to Mars surface from the     original 
> rocket or Mother ship.  Upon completion of their time on Mars,     
> the astronauts would direct their spaceship towards Earth, to return 
> to home.
>            However, instead of returning directly to Earth, the 
> spaceship would      land on the Moon, not using a lunar/Mars type 
> lander.  The spaceship would     land directly on the Moon's surface,
>  not to return to Earth anytime soon.     The spaceship would be 
> left on the Lunar surface, complete with its     reactor intact. 
>  There's not much weather or wind storms on the Moon, so the     
> spaceship could stay there a long time without dispersal of any fission
>      products or the original Uranium fuel.
>           So, this leaves the astronauts on the Moon with the 
> scientific samples,     stored data on computers, etc.  What happens 
> next???  A second      chemically propelled rocket is sent to the 
> Moon,  and using a Lunar lander     the astronauts are picked up and 
> return to Earth in the second spacecraft.     Mission accomplished.  
> I didn't say the space mission would be inexpensive.
>           In 200 years (a fair number of half-lives) the original 
> fission reactor      could be picked up from the lunar surface and 
> returned to Earth for     processing and/or storage.
>           If we ever perfect a fusion propelled rocket system, much 
> of the preceding     described effort becomes unneccessary.
>           Just something to think about.  I think such a fission 
> propelled rocket     system could be built in the relatively near 
> future.  Oh my, jobs for      Health Physicists and/or Nuclear 
> Engineers in space.
>          The airplanes/jets which takeoff vertically are called Harriers.
>          Another few years of relatively few (named> hurricanes 
> and/or          tropical storms like 2008 (so far> and I'll have to 
> say that the global         warming hypothesis is fizziling out.
>          Now, get back to work????
>          I hope you have a wonderful week.
>          Regards,   Joseph R. (Joe> Preisig, Ph.D.
>      <BR><BR><BR>**************<BR>Looking for simple solutions to 
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Jerry Lahti
Naperville IL

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