Re: SPACE: Lunar Warfare

James Rogers (
Wed, 15 Jan 1997 16:30:59 -0800

At 06:24 PM 1/13/97 +0000, Mark Grant wrote:
>On Mon, 13 Jan 1997, James Rogers wrote:
>> After much
>> nasty calculation based on the above values, you will be disappointed to
>> learn that the safe distance from ground zero is between 500-1000 meters for
>> a 1Mt surface burst, depending on soil conditions.
>Hmm, isn't that about the same figure that I gave, if you scale it for 1MT
>rather than 10MT? That is, 500 - 1000 x 10^(1/3) ~= 1200 - 2400. AFAIR I
>said 1500 for 10 MT, and actually that was diameter rather than radius so
>your figure would be larger.

After doing additional research, I may have to modify my above stated
figures a little bit. The 500-1000 meter range for a 1-Mt lunar surface
burst was extrapolated from nuclear data for surface bursts on earth
(obviously, since there have never been lunar nuclear tests). The problem
is that it was difficult to remove atmospheric related cratering effects
from blast and ground shock related effects, since my engineering books
always assume that the blast occurs on earth.

It occurred to me that studying *underground* nuclear tests, I could get
information on nuclear explosions in an environment where atmospheric
factors are not involved. Unfortunately, nobody publishes underground
nuclear test data. What I was able to do, however, was get information on
yield and crater dimensions after the underground chamber collapsed for a
couple underground tests. There are standard civil engineering equations
that allowed me to reconstruct the underground blast damage effects based on
crater dimension and shape. Based on this data, I constructed a new set of
data for lunar explosions based on underground nuclear tests. I think this
data may be more accurate, since it only reflects ground shock related damage.

I based my results on a 10-Mt lunar surface burst, since this seems to be
the "standard" baseline for argumentative purposes.

For a lunar 10-Mt yield, distance from ground zero:

0-500 meters :you are screwed
500-800 meters :hardened shelter required
>800 meters :standard lunar structure should survive

These figures assume that underground nuclear tests are reasonably accurate
models for calculation of lunar nuclear effects.

-James Rogers