Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: Re: Nuclear testing in space
Date: Sun, 25 Oct 1998 17:18:01 GMT

In article <19981025073531.04668.00000334@ngol06.aol.com>,
JCMullen99 <jcmullen99@aol.comnospam> wrote:
>>>...veiled references to actually testing nuclear weapons in space...
>>There was a little bit of it in the late 50s and early 60s, just before
>>the Test Ban Treaty outlawed it.
>
>Operation Argus...

Actually, Argus (summer 1958) was a relatively minor test series, although
it's noteworthy because it did the first in-space tests and because it was
done in such secrecy.  The Argus warheads were very small.  The more
significant in-space tests were Starfish in July 1962, and three Russian
in-space tests later that year.

> The motivation for this secret series was a theory developed by the brilliant
>but eccentric physicist Nicholas Christofilos at
>Lawrence Radiation Laboratory (LRL).

Incorrect -- Christofilos was at Livermore.

>He had predicted that military
>significant effects would be produced by injecting
> charged particles from nuclear explosions into near space to create artificial
>Van Allen belts.

Incidentally, he also predicted the natural Van Allen belts three months
before Van Allen discovered them.  The reason they are called Van Allen
belts and not Christofilos belts is that Christofilos's work was highly
secret.

The combination of a new and still agile military agency -- ARPA -- and
the perceived importance of Christofilos's idea led to amazingly fast
results.  Argus ran in-space experiments on the concept, using live
nuclear weapons, less than a year after Christofilos first proposed it!

>This series sought to prove (or
> disprove) his theory by actually creating such a belt. Operation Argus has
>been termed the "world's largest scientifc
> experiment" encompassing as it did the space surrounding the entire Earth. The
>tests essentially confirmed his predictions.

Only for a very generous meaning of "essentially".  What Christofilos
wanted to do was create artificial radiation belts strong enough to fry
incoming ICBM warheads.  Argus did not actually try to do that, but it
explored the basic physics involved, and the results were negative:  it
won't work.  Oh, the electrons are trapped as Christofilos predicted, but
the discovery of the Van Allen belts had already settled *that*.  Argus's
objective was to determine whether they were trapped well enough to be a
practical defence against missiles, and the answer was no.

The best reference I've found on this is Herbert F. York's "Making
Weapons, Talking Peace".  York was director of Livermore when Christofilos
came up with his brainstorm, and moved to ARPA just in time to be charged
with organizing Argus.
--
Being the last man on the Moon is a |  Henry Spencer   henry@spsystems.net
very dubious honor. -- Gene Cernan  |      (aka henry@zoo.toronto.edu)

From: "Geoffrey A. Landis" <geoffrey.landis@sff.net>
Newsgroups: sci.space.tech
Subject: Re: Orion Shall Rise
Date: 26 Aug 1999 18:30:29 GMT

In article <FGwCFA.4Ht@spsystems.net> Henry Spencer, henry@spsystems.net
writes:
>>> The comment I saw was that a single good-sized H-bomb exploded a fair
>>> ways up might well kill every satellite in Earth orbit, except the ones
>>> which happened to be behind Earth at the time.
>>
>>Including Geosynchronous?
>
>Yes.  Anything this side of the Moon.

I find that hard to believe.  Starfish Prime was a good-sized H-bomb
(1962; 1.4-megatons exploded at an altitude of 248 miles) degraded
satellites in LEO due to accumulated electron fluence, but I wouldn't say
it "killed every satellite this side of the moon."  Satellites these days
are somewhat harder against radiation.

Do you have a source?

____________
Geoffrey A. Landis
http://www.sff.net/people/geoffrey.landis

From: rk <stellare@nospamplease.erols.com>
Newsgroups: sci.space.policy
Subject: Re: Orion (was: Re: HMX gets NASA contract)
Date: Sun, 03 Sep 2000 13:21:33 -0400

"Paul F. Dietz" wrote:

> rk wrote:
>
> > It is rather well known that even a small nuclear explosion at altitude can
> > "pump the belts" which will greatly increase the radiation levels in LEO.
>
> In *LEO*?  I'm a bit skeptical about that.

I've heard this a number of times - it's out of my direct field though.

I just found one public domain reference that covers it, at least in part.
Here's some of the points in the graph they supply, altitude (km) vs. dose
(rads(Si)), 30 deg inclination, standard 100 mil Al shielding, 30-day exposure to
a nuclear weapon-enhanced electron flux.

     Altitude (km)    Dose (krads)
          200             700
          300            1700
          400            3000
          500            7000
         1000           20000
         2000           60000

As I said, this is not my direct field, I heard it a number of times in different
places.  The above numbers and some description of what's going on: Space Mission
Analysis and Design, 2nd edition, Larson and Wertz, pp. 215-218 [section written
by Paul Nordin, Grummand Aerospace Corp.  If I misinterpreted something or read
it wrong or remember it wrong or if there is no information, then please delete
this post.

While the peak is definitely not in LEO, these radiation numbers behind 100 mil
of shielding are most definitely large for LEO altitudes.  Around 600 km or so is
a popular LEO orbit for many missions.  They didn't have a chart showing the
effect of inclination on these numbers.  Currently, in many civilian LEO
applications, for examples, parts with a capability of around 5 krad(Si) for
total dose are used.  A good example is the popular Intel 80386.

rk

Newsgroups: sci.space.policy
From: henry@spsystems.net (Henry Spencer)
Subject: Re: Orion (was: Re: HMX gets NASA contract)
Date: Fri, 8 Sep 2000 02:15:58 GMT

In article <39B27DC7.C8399169@interaccess.com>,
Paul F. Dietz <dietz@interaccess.com> wrote:
>> It is rather well known that even a small nuclear explosion at altitude can
>> "pump the belts" which will greatly increase the radiation levels in LEO.
>
>In *LEO*?  I'm a bit skeptical about that.

It's probably correct.  Most of the radiation dose in LEO comes from
passes through the South Atlantic Anomaly, which is basically a
low-hanging region of the inner Van Allen belt.
--
Microsoft shouldn't be broken up.       |  Henry Spencer   henry@spsystems.net
It should be shut down.  -- Phil Agre   |      (aka henry@zoo.toronto.edu)