Mining the moon for unlimited Energy.

(Alex Terrell) writes:

Any idea who started this theory that He3 is easy to burn?

I don't think _anybody_ ever claimed it was "easy to burn" --- they merely
claimed that He3 and other so-called "advanced" fuels were _cleaner_ than D/T.

I suspect that this whole thing started out as a classic case of putting
the cart before the horse, by unimaginative people (possibly from NASA)
who started out from the assumption that going back to the Moon would
_ALWAYS_ be hideously expensive, and so therefore they needed to find
_some_ absurdly rare and even =MORE= expensive substance that was also
more abundant on the Moon than on the Earth to try and justify the trip.
Apparently, "Solar-wind implanted He3 for fusion reactor fuel" was the only
thing they could think of that had extremely low mass, extremely high value,
and was more abundant on the Moon than on the Earth (again supporting the
hypothesis that they not particularly imaginative people...).


I know Zubrin did chapters on it in his book Entering Space. Is he guilty?

IIRC, it pre-dates Zubrin substantially. In fact, I vaguely recall that
it might even have appeared on a page or two of O'Neill's "The High Frontier"...


-- Gordon D. Pusch

perl -e '$_ = \n"; s/NO\.//; s/SPAM\.//; print;'

Gordon D. Pusch wrote:

Hmph. On re-examining Rider's dissertation, it appears you are correct,
and my memory of a factor of 15 was wildly wrong. Assuming quasi-neutrality,
separate maxwellian distributions for ions and electrons, =NO_ energy losses
except bremsstrahlung, and that =ALL= the fusion-product power can somehow
be magically recycled back into heating the fuel ions and _NOT_ into heating
the electrons, Rider gets:

fuel | P_brem/P_fus
--------+--------------
D-T | 0.007
D-He3 | 0.19
D-D | 0.35

(other fuels clipped)

The separate maxwellian distributions for ions and electrons follows
naturally from the energy loss via bremsstrahlung. This process draw
energy from the electrons, so to balance their temperature must be
lower than that of the ions.

I'll also add that the P_brem/P_fus ratio for D-3He in the table
assumes a 1:1 ion ratio. Increasing the fraction of D reduces
the P_brem/P_fus ratio a bit (see figure 7.3 in the thesis). This
also increases the neutron output, but (for the case of rapid
removal of T from the plasma) it's still well below that of DT
or DD plasmas.

It's not clear to me that the P_brem/P_fus ratios for DT include
the 80% of the fusion energy that goes into the neutrons. If
this is the case, the figure is misleading, since most of the fusion
energy from a fusion D-3He plasma will be in charged particles
and will be immediately available for heating the plasma.

The large tritium inventory in this case (waiting for all that
removed tritium to decay back to 3He) is worrisome.

Paul

Jim Logajan wrote:
(Gordon D. Pusch) wrote:

"Paul F. Dietz" writes:

Where does this 'exceeds its energy generation rate by more than an
order of magnitude' come from? The ideal situation I recall (optimal
plasma conditions, 'hot ion mode') was 19% of the energy goes into
bremsstrahlung.

That's not what I remember from Art Carlson's (sadly defunct) webpage
summarizing the Rider Thesis. What I remember was that bremsstrahlung
losses exceed energy generation by a factor of 15; I will have to dig
out the copy of the Rider Thesis Jim Logajan kindly loaned me and see
if I can find the exact figure, but I'm pretty sure that a factor of
15 is correct.

MIT has placed many of it's students thesis online. Todd Rider's thesis can
be viewed entirely online he

http://theses.mit.edu/Dienst/UI/2.0/...1?nsections=13

The burning of D-He(3) in a Maxwellian device, i.e. a PLASMAK[tm]
engine, is allowed, provided the power recirculation has a high Carnot
efficiency.

I haven't checked, but has RWBussard commented on the Rider "Thesis"?
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"Gordon D. Pusch" wrote in message
...

IIRC, it pre-dates Zubrin substantially. In fact, I vaguely recall that
it might even have appeared on a page or two of O'Neill's "The High
Frontier"...

I doubt that. O'Neill was pushing the use of lunar resources to build SPS.
I think he was of the opinion that fusion was not going to make SPS obsolete
in any foreseeable future.

He did talk about harvesting lunar ice at the poles though, the existence of
which was purely theoretical at the time.

--


Regards,
Mike Combs
----------------------------------------------------------------------
We should ask, critically and with appeal to the numbers, whether the
best site for a growing advancing industrial society is Earth, the
Moon, Mars, some other planet, or somewhere else entirely.
Surprisingly, the answer will be inescapable - the best site is
"somewhere else entirely."

Gerard O'Neill - "The High Frontier"

"Mike Combs" wrote in message ...
"Gordon D. Pusch" wrote in message
...

IIRC, it pre-dates Zubrin substantially. In fact, I vaguely recall that
it might even have appeared on a page or two of O'Neill's "The High
Frontier"...

I doubt that. O'Neill was pushing the use of lunar resources to build SPS.
I think he was of the opinion that fusion was not going to make SPS obsolete
in any foreseeable future.

He did talk about harvesting lunar ice at the poles though, the existence of
which was purely theoretical at the time.

Having worked for two years at Forrestal and personally known G.K.
O'Neill, the most charitable thing that anyone who worked there would
say about him was that, quite fortunately, he didn't come to work very
often! :-)


Harry C.

"Harry Conover" wrote in message
om...

Having worked for two years at Forrestal and personally known G.K.
O'Neill, the most charitable thing that anyone who worked there would
say about him was that, quite fortunately, he didn't come to work very
often! :-)

What's Forrestal? I was only aware of his research/teaching career at
Princeton, and his ultimately unsuccessful bid as an entrepreneur with
Geostar.

--


Regards,
Mike Combs
----------------------------------------------------------------------
We should ask, critically and with appeal to the numbers, whether the
best site for a growing advancing industrial society is Earth, the
Moon, Mars, some other planet, or somewhere else entirely.
Surprisingly, the answer will be inescapable - the best site is
"somewhere else entirely."

Gerard O'Neill - "The High Frontier"

"Mike Combs" wrote in message ...
"Harry Conover" wrote in message
om...

Having worked for two years at Forrestal and personally known G.K.
O'Neill, the most charitable thing that anyone who worked there would
say about him was that, quite fortunately, he didn't come to work very
often! :-)

What's Forrestal? I was only aware of his research/teaching career at
Princeton, and his ultimately unsuccessful bid as an entrepreneur with
Geostar.

It's the large government funded and Princeton University admisistered
research center located off US Route 1 in Plainsboro, New Jersey just
outside of Princeton.

At the time that I worked there, circa 1969, it was host to the
Princeton-Pennsylvania accelerator project, part of Project Matterhorn
relating to the (then top secret) Lyman Spitzer Stellerator controlled
fusion program, and an aeronautical research project that seem at that
time to primarily focus on ground effects machines and hovercraft.

For a brief history of Forrestal Research Center, see:

http://www.princeton.edu/pr/pwb/02/0520/08a.shtml

Jame Forrestal, for whom the research center was named, was a former
secretary of defense who ended his too brief life via suicide. At
least for a brief moment he, unlike most of us, 'soared with the
eagles'.

For a government bio on James Forrestal, see:

http://www.defenselink.mil/specials/.../forrestal.htm

Harry C.

p.s. Back in 1969, I and some of my physicist/engineer friends at
Forrestal became enamored with the romance, beauty, and emotional
impact of shooting large, display fireworks. Many of the mortars that
we employed to fire these 3 to 6" diameter devices were constructed in
the machine shops at Forrestal, and welded by some of the finest
heli-arc welding machines and skilled welders in existence at that
time. We, often accompanied by the head of Princeton's Physics
department, Dr. White (former director of Brookhaven labs), would
often lauch these large fireworks from on top of the large, earthen
shielding mound that covered the entire accelerator. Locals simply
assumed that the lights and flashes in the sky were the result of
'atomic research' taking place in the facility. Gawd, if they had only
known the facts we could have all, Dr. White included, landed up in
the slammer! The strange lights in the sky above Forrestal gradually
assumed the dimensions of an urban myth, and even became part of the
'patter' of local tour bus operators on passing by the facility.
Evidently it was believe that our fireworks were the result of atomic
bomb testing ongoing beneath the shielding mound! Fortunately, I left
the area and went to work for Kodak in Rochester long before the sh*t
hit the fan, if it ever did.

We also know how to beam energy over long distances.

And how is that then???


"Manfred Bartz" wrote in message ...
(Sanjay) writes:

There is plenty of energy on moons crust that if we can mine
Helium 3 Gas out of Moons crust we can solve all our energy
needs for 1000 years.

There is plenty of energy coming from the natural fusion reactor in
the center of our planetary system -- good for a few Billion years

A pound of Helium-3 is having energy equivalent of 1 Million
ton of Coal.

There is just one minor problem: No one yet knows how to build a
useful fusion reactor. Even if we could build one, we would have
messy radiation problems to deal with.

OTOH, we know how to build solar panels. We also know how to beam
energy over long distances. It is just a matter of economics and/or
political will to move ahead with solar power satellites.

I am not saying that there is no place for nuclear or fusion power,
I just think solar will in the end be easier and more economical.
Nuclear or fusion power would probably be ideal for deep space
missions; or maybe anti-matter if it can be produced in sufficient
quantity and by a cheap enough process.

--
Manfred Bartz

noodle doodle wrote:
We also know how to beam energy over long distances.


And how is that then???

Microwaves. But from the moon the transmitting antenna would be many
kilometers across.

I'd read that Japanese scientists have been working with lasers, you'd
have to search google. I think efficiency is a tough nut there.

But I would go with a chain and sprockets myself.

Best, Dan.

noodle doodle wrote:

We also know how to beam energy over long distances.

And how is that then???

Microwave beam, rectifying antenna.

Paul