Re: Nuclear rockets.

On Apr 16, 5:00 pm, BradGuth <bradg...@xxxxxxxxx> wrote:
On Apr 16, 11:38 am, Willie.Moo...@xxxxxxxxx wrote:





However, your mainstream box limited comprehension

Means we both understand the physics and engineering realities
involved but you choose to ignore those realities so you can mentally
masturbate about the topic without reference to reality.

 of setting up
easily established moon anchored tethers,

You yourself said they'd require 256 million tons of materials -
several grand coulee dams - and required 256,000 tons of robots and
tooling on the moon.  If you put 256,000 tons of material on the moon
you could turn water into hydrogen and oxygen and refuel spaceships
arriving empty on the moon and achieve the same thing.

Its only when mass flow to and from the moon gets far far bigger that
tethers begin to make sense.  Given exponential rates of growth, they
won't take long to develop, but they won't develop until they make
economic and logistical sense.

and of the great worth as to
the subsequent future advancements of science and even on behalf of
accomplishing the very salvation of Earth is noted,

Low cost high performance rockets will save earth long before the
first tether is built

for the same
reasons you would never contribute a constructive and otherwise
informative word on behalf of relocating our moon, as to interactively
halo orbit that moon within Earth's L1 is equally forever Mook taboo/
nondisclosure rated.  Way to go, lord all-knowing Mook.

I'd top-posted for the benefit of others.
. - BG

Your continual out-of-context based nayism that's focused only upon
the most negatives of each and every conceivable aspect, is noted.

Nonsense. If you're going to send 256,000 tons of materials to the
moon with chemical rockets, the highest best use of it IS NOT to build
a tether (since we don't know how to do that anyway) but to find a
source of water, and generate hydrogen and oxygen with it to refuel
our spacecraft. In fact you don't need 256,000 tons - something like
5 tons is just fine - a small space nuclear reactor like NEBA III, a
water source, and an electrolysis cryogenic refrigeration unit,
attached to a spent landing stage with cryogenic propellant tanks will
work just fine. A lot easier.

Check it out. To soft land on the moon arriving along a lunar free
return trajectory from Earth, requires a delta vee of 2.48 km/sec.
With an exhaust speed of 4.46 km/sec - that means the vehicle has a
propellant fraction of 42.66% With a structural fraction of 15% -
that leaves 42.34% of the total stage mass as payload.

So, a multi-element chemical launcher derived from the Space Shuttle's
external tank, places 420 tons on a Lunar Free Return trajectory.which
means you can land 177 tons on the lunar surface. Refueling with 180
tons of propellant, allows you to life 177 tons OFF the lunar surface
and fly it back to Earth. Without a tether.

Without refueling the lunar ship would have to carry enough fuel along
to get back to Earth - which subtracts from useful payload. The delta
vee in this case is DOUBLE 2.48 km/sec or 4.96 km/sec - which means
the vehicle in that case has a propellant fraction of 67.12% - with
the same 15% structural fraction that leaves 17.88% payload fraction.
Which means the same ship can carry only 75 tons to the lunar surface
- a loss of 100 tons of useful payload!!

Of course a tether would reduce propellant costs to zero mass - which
means the entire 420 tons - less 63 tons of structure - would be
available to land and lift from the lunar surface - a net payload of
357 tons

So,

With a 420 ton payload arriving at the moon from Earth along a lunar
free return trajectory, here is what you get for each infrastructure
improvement;


Wild lunar highlands - 75 tons - zero improvements
Lunar refueling - 177 tons - 75 tons hardware + 63 tons 'landed'
storage tank
Tether 357 tons - 256 million tons hardware built on the moon
with
256,000 tons of harware

So, to get a 180 tons increase per flight you need to invest 256,000
tons of hardware, so you need 1,420 flights to break-even for that,
and you need to process 256 million tons of lunar material equivalent
to 1.42 million flights supported by lunar materials to break even
there -

Now with a $12 billion fleet of 3 launchers you'd have a launch rate
of about once a week with this technology. That's 50 launches a year
- So, it would take 28,400 years of weekly flights with this fleet to
actually be ahead - assuming the tether needs no maintenance in all
that time.

This isn't nayism - whatever that means - its realism.

Now if you had advanced nuclear pulse spacecraft with 10,000 km/sec
exhaust speeds, your savings would be nil - especially if you reloaded
on the moon when you were there. But your costs would be so small,
that if you are bringing asteroids and kuiper belt objects back to the
moon with your nuclear rockets, it makes sense to build a big tether.
And once you have a tether? It makes sense to use it everyway you
can. Once you know how to build it.

What is a real block to progress is saying we've got to find nanotubes
or whatnot and figure out how to build a tether,and then go build one
before we can justify building big launchers. That's real nayism -
and its precisely the bone headed pathway you'd have us take. any
reasonable analysis shows that tethers won't be important until we're
terraforming worlds with asteroids and kuiper belt objects,
transported there with nuclear pulse technology - then the massive
investment in hardware makes sense compared to the total mass
transfered by it.


I have no doubt that nuclear rockets will also do this badly failing
world

utter bull***.

that's gotten far too spendy

if you'd actually get a job its not so bad

and bloody

if you'd actually vote in an election it wouldn't be so bad

for far too many
innocent folks,

what have you done personally today this week this month to make a
real difference to someone who needs help? I thought so.

whereas such nuclear technology will accomplish a
great deal of good for those few of us still alive and kicking with
spare loot

innovation is always taken first by those with surplus capital to
risk. It would be a hardship and foolish to ask the poorest to take
such risks. Once the learning curve has been traversed, prices drop
and use of new technology expands. Look at digital watches in the
1970s - they were luxury items, now you buy them in gumball machines.

after your WWIII deals

War destroys wealth it does not create wealth.

with the fossil

fossil fuels are our primary energy supply. If you want to change
things, that's where you start. you don't end up staying there
however.

and yellowcake
energy

nuclear power too is something that we actually can do something with
- rather than dreaming about tethers that we don't know how to build
yet.

cartel fiasco

cartels do not promote growth and price reduction So, i'm against
them.

that yourself and others

I'm the new kid on the block - the upstart - just cause i've done a
few deals doesn't mean that has changed.


of your three-faced
multitasking kind

You just say that because it takes the focus off your lies and
stupidity and makes you feel a tiny bit better. Get help Brad you
need it.

seem to see nothing the least bit wrong

You got that right - things are going GREAT in my life. How about
yours?


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