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Mining the moon for rocket fuel to get us to Mars



 
 
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  #11  
Old June 2nd 17, 11:54 AM posted to sci.space.policy
Jeff Findley[_6_]
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Posts: 1,624
Default Mining the moon for rocket fuel to get us to Mars

In article ,
says...
That and we're decades away from "real" artificial intelligence.
Anything approaching that today has as its input many man-years of
software development done by people like me. Hell, we're years away
from making all software products multi-threaded yet desktop machines


today rarely have less than 4 physical cores (8 with hyper-threading).


AI is a solved problem. You don't get that.


No, AI is not "a solved problem". AI is a research topic.

https://www.youtube.com/watch?v=7Pq-S557XQU

That YouTube video is just more b.s. It doesn't show that AI exists
that would support your repeated assertion that we're near some
"singularity". We're not.


What we have today are computer programs written by people like me. We
have degrees in engineering and computer science and our output isn't
anywhere near AI good enough to replace ourselves. I've been doing this
for close to three decades now and we're nowhere near your starry eyed
vision of AI taking over the world.

Until so called AI can truly surpass the learning capacity of a human
being, we won't be past the so called "singularity". We're a hell of a
long way away from that.


The rest of your posting has been deleted in my follow up as it is
nothing but you calling me a liar (and other assorted insults) without
actual evidence to the contrary. You really suck at arguing your point
if all you can do is hurl insults. You sound like you need to talk to
your counselor and have your meds checked.

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.
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  #12  
Old June 3rd 17, 01:21 PM posted to sci.space.policy
Alain Fournier[_3_]
external usenet poster
 
Posts: 337
Default Mining the moon for rocket fuel to get us to Mars

On May/31/2017 at 6:57 AM, Jeff Findley wrote :
In article , says...
There is quite a lot of "exercise for the student" type problems here.
There is a lot of work & study needed about lunar industrialization for
sure including mining.

One factor that may get some consideration down the road is the idea of
what I'd call incremental industrial "densification". The idea being
that lightweight gear is first sent up
that has limited capacity for manufacture of the "heavy gear". Heavy
feed stock ( steel, etc) would then be sent
up subsequently for lunar manufacture. Enabling a heavy mfg. capability
via bootstrapping. At this point my conjecture
is pretty much a total hand wave, but I could at least see it as a
possibility. Would need some math to determine if
this would be preferable to just shipping up the heavy equipment
directly. I suppose if the scale is massive enough
the bootstrap approach might be the only really feasible one. Further
study needed....


I think the "further study needed" is the key here. Researchers don't
really know how they'd do this, so they're fishing for funding. Don't
get me wrong, this is certainly worth doing some work on, but this is
not a next 10 or 20 year solution. It's more like a next 25 to 100 year
solution.

But no, we'll do it all with SLS. Why waste money on studies?


Flags and footprints. We couldn't possibly do anything differently than
Apollo now could we? :-(

The reality is there is so much between the SLS approach and the "living
completely off the land" approach. I don't see "living off the land"
becoming viable until you can start launching heavier bits like machine
tools without resorting to making them out of aluminum, titanium, and
unobtainium. Shaving every last gram off of payloads due to high launch
costs is freaking expensive! It results in one-off payloads that might
work, or they might not.

To build a colony, we need to get to the point where we're buying
machine tools "off the shelf" and simply shipping them to the moon and
Mars. Run them in pressurized environments so astronauts can service
them in "shirt sleeves". By then, astronauts will be selected for their
skill at fixing machine tools, not for their ability to fly a fighter
jet in combat or because they have the most college degrees.


****. I've got college degrees, but fixing machine tools, not my forte. :-)


Alain Fournier

  #13  
Old June 5th 17, 02:06 AM posted to sci.space.policy
Greg \(Strider\) Moore
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Posts: 599
Default Mining the moon for rocket fuel to get us to Mars

"Jeff Findley" wrote in message
...

First, this isn't my "subject", it's the title of this article:

Mining the moon for rocket fuel to get us to Mars
May 14, 2017 8.04pm EDT ?Updated May 18, 2017 9.01am EDT
http://theconversation.com/mining-th...-to-get-us-to-
mars-76123

I saw this article (or a variation of it from another online
publication) on Twitter. I replied something to the effect that this
article glosses over all of the hard stuff, like the fact that the lunar
soil and rock is horribly abrasive and that mining equipment isn't
anything like the lightweight rovers that NASA/JPL has flown in the
past. For crying out loud, JPL keeps using ALUMINUM for the rover
wheels to keep them light, even though they're wearing holes in the
things after less than 100 miles. Mining equipment can't be that weak!
Anyway, I replied that mining equipment is *really heavy* because it's
made of steel and hardened steel.

The response by one Twitter follower was along the lines of, "That's why
the mining equipment will be built on the moon from local materials".


At that point, "I couldn't even". I mean WTF? So, to build mining
equipment on the moon, you're going to build an entire freaking factory,
from local materials?!?!? So, WTF are you going to use to mine the
materials to build the factory?!?!?!?


Don't get me wrong, I think *eventually* we'll be mining the moon for
water to turn into LOX and LH2 (or possibly methane) to supply a fuel
depot in lunar orbit. But, needless to say, I think the supporters of
this notion are daft if they think it's going to happen in the next 20
years or so by building a freaking factory on the moon that's capable of
building mining equipment that's not JPL class "toys" that wear out
faster than you can build them.

Jeff


Yeah, I use a very simple first order approximation for this:
the mass of the fuel you'll get from the Moon has to be greater than fuel
used to get the mass to mine it to the Moon, otherwise it's a net loss.

Simply put, if you're going to extract say 100 kilotons of fuel from the
Moon, you're going to have to use less than 100 kilotons of fuel getting
your mining and processing equipment there, otherwise it's a waste.

I think people look at in-situ fuel processing on Mars and figure the Moon
makes even more sense. But processing atmosphere (even a thin one) to
extract Carbon is far easier than mining the surface of the Moon.

I do agree, at some point we'll process fuel on the Moon, but we're a LONG
ways from there.


--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net
IT Disaster Response -
https://www.amazon.com/Disaster-Resp...dp/1484221834/

  #14  
Old June 5th 17, 07:56 AM posted to sci.space.policy
Niklas Holsti
external usenet poster
 
Posts: 60
Default Mining the moon for rocket fuel to get us to Mars

On 17-06-05 04:06 , Greg (Strider) Moore wrote:
"Jeff Findley" wrote in message
...

First, this isn't my "subject", it's the title of this article:

Mining the moon for rocket fuel to get us to Mars
May 14, 2017 8.04pm EDT ?Updated May 18, 2017 9.01am EDT
http://theconversation.com/mining-th...-to-get-us-to-
mars-76123

I saw this article (or a variation of it from another online
publication) on Twitter. I replied something to the effect that this
article glosses over all of the hard stuff, like the fact that the lunar
soil and rock is horribly abrasive and that mining equipment isn't
anything like the lightweight rovers that NASA/JPL has flown in the
past.


[snip]

Don't get me wrong, I think *eventually* we'll be mining the moon for
water to turn into LOX and LH2 (or possibly methane) to supply a fuel
depot in lunar orbit. But, needless to say, I think the supporters of
this notion are daft if they think it's going to happen in the next 20
years or so by building a freaking factory on the moon that's capable of
building mining equipment that's not JPL class "toys" that wear out
faster than you can build them.

Jeff


Yeah, I use a very simple first order approximation for this:
the mass of the fuel you'll get from the Moon has to be greater than
fuel used to get the mass to mine it to the Moon, otherwise it's a net
loss.

Simply put, if you're going to extract say 100 kilotons of fuel from the
Moon, you're going to have to use less than 100 kilotons of fuel getting
your mining and processing equipment there, otherwise it's a waste.


Perhaps you on purpose ignored this factor in your approximation, but
surely the *location* of the fuel must be considered?

If you use 100 kilotons of fuel to send equipment to the Moon, most of
that fuel is used up close to the Earth, and will not reach the Moon. If
that equipment then produces 100 kilotons of fuel on the Moon, that fuel
is on the Moon, which is "half-way to anywhere".

You would surely have to use *much* more than 100 kilotons of fuel to
deliver a payload of 100 kilotons of fuel from the Earth's surface to
the Moon's surface.

--
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
. @ .
  #15  
Old June 5th 17, 11:43 AM posted to sci.space.policy
Jeff Findley[_6_]
external usenet poster
 
Posts: 1,624
Default Mining the moon for rocket fuel to get us to Mars

In article ,
lid says...
Yeah, I use a very simple first order approximation for this:
the mass of the fuel you'll get from the Moon has to be greater than
fuel used to get the mass to mine it to the Moon, otherwise it's a net
loss.

Simply put, if you're going to extract say 100 kilotons of fuel from the
Moon, you're going to have to use less than 100 kilotons of fuel getting
your mining and processing equipment there, otherwise it's a waste.


Perhaps you on purpose ignored this factor in your approximation, but
surely the *location* of the fuel must be considered?

If you use 100 kilotons of fuel to send equipment to the Moon, most of
that fuel is used up close to the Earth, and will not reach the Moon. If
that equipment then produces 100 kilotons of fuel on the Moon, that fuel
is on the Moon, which is "half-way to anywhere".

You would surely have to use *much* more than 100 kilotons of fuel to
deliver a payload of 100 kilotons of fuel from the Earth's surface to
the Moon's surface.


So let's revise the original statement a bit. If the goal is to refuel
a depot in lunar orbit, the fuel you mine, refine, and launch to that
depot must exceed the amount of fuel it took to originally land the
mining equipment, lander, and landing fuel when starting from roughly
the same lunar orbit as the depot. Ignore the delta-V to get to lunar
orbit, because it's the same for the 100 kilotons of fuel put in lunar
orbit or the 100 kilotons of lunar lander, fuel, and mining equipment
put in lunar orbit.

Yes, you can split hairs and come up with "direct" landing trajectories
which might be more efficient, but we're trying to come up with a first
order approximation to illustrate how hard it will be to "break even" on
the mining equipment. It's not going to be as easy as it seems. Lunar
soil is terribly abrasive and will wear out "lightweight" aerospace
materials like aluminum very quickly on equipment that is in moving
contact with it.

And, the cost of that lunar landing stage and mining equipment is going
to be higher than the cost of the fuel mass sent in the other scenario.
We're not even comparing costs yet, just mass "cost".

Jeff
--
All opinions posted by me on Usenet News are mine, and mine alone.
These posts do not reflect the opinions of my family, friends,
employer, or any organization that I am a member of.
  #16  
Old June 5th 17, 02:09 PM posted to sci.space.policy
Greg \(Strider\) Moore
external usenet poster
 
Posts: 599
Default Mining the moon for rocket fuel to get us to Mars

"Niklas Holsti" wrote in message ...

On 17-06-05 04:06 , Greg (Strider) Moore wrote:
"Jeff Findley" wrote in message
...

First, this isn't my "subject", it's the title of this article:

Mining the moon for rocket fuel to get us to Mars
May 14, 2017 8.04pm EDT ?Updated May 18, 2017 9.01am EDT
http://theconversation.com/mining-th...-to-get-us-to-
mars-76123

I saw this article (or a variation of it from another online
publication) on Twitter. I replied something to the effect that this
article glosses over all of the hard stuff, like the fact that the lunar
soil and rock is horribly abrasive and that mining equipment isn't
anything like the lightweight rovers that NASA/JPL has flown in the
past.


[snip]

Don't get me wrong, I think *eventually* we'll be mining the moon for
water to turn into LOX and LH2 (or possibly methane) to supply a fuel
depot in lunar orbit. But, needless to say, I think the supporters of
this notion are daft if they think it's going to happen in the next 20
years or so by building a freaking factory on the moon that's capable of
building mining equipment that's not JPL class "toys" that wear out
faster than you can build them.

Jeff


Yeah, I use a very simple first order approximation for this:
the mass of the fuel you'll get from the Moon has to be greater than
fuel used to get the mass to mine it to the Moon, otherwise it's a net
loss.

Simply put, if you're going to extract say 100 kilotons of fuel from the
Moon, you're going to have to use less than 100 kilotons of fuel getting
your mining and processing equipment there, otherwise it's a waste.


Perhaps you on purpose ignored this factor in your approximation, but
surely the *location* of the fuel must be considered?

If you use 100 kilotons of fuel to send equipment to the Moon, most of that
fuel is used up close to the Earth, and will not reach the Moon. If that
equipment then produces 100 kilotons of fuel on the Moon, that fuel is on
the Moon, which is "half-way to anywhere".

You would surely have to use *much* more than 100 kilotons of fuel to
deliver a payload of 100 kilotons of fuel from the Earth's surface to the
Moon's surface.


Not that much more really. And as I said, it's a first order approximation.
There's a lot more math involved than simply this.
But if you figure the delta V just to get to the Moon is approximately
12.52km/sec, and the delta-V from lunar transfer to surface is probably
about 2.55, and 2.55 back out, so that's less than 1/2. Sure, you can
probably play some numbers there (direct impact, etc.) but it doesn't change
the first order approximation much.
Again as a first order approximation, figure the energy used to land will be
about the same as taking off.

Now, figure if you want to go to Mars, from lunar transfer to Mars is
approximately less than landing on the Moon, especially if you can use some
aerobraking.

So again, first order approximation, I stand by my analysis.


--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net
IT Disaster Response -
https://www.amazon.com/Disaster-Resp...dp/1484221834/

  #17  
Old June 7th 17, 05:39 PM posted to sci.space.policy
Niklas Holsti
external usenet poster
 
Posts: 60
Default Mining the moon for rocket fuel to get us to Mars

First, I want to highlight that I'm not advocating fuel production on
the Moon; I am not competent to evaluate the difficulty of that. I'm
only doubting the "first order approximation" that compares the amount
of fuel needed to send the equipment to the Moon (from the Earth's
surface, it is assumed) to the amount of fuel produced on the Moon.

On 17-06-05 13:43 , Jeff Findley wrote:
In article ,
lid says...
Yeah, I use a very simple first order approximation for this:
the mass of the fuel you'll get from the Moon has to be greater than
fuel used to get the mass to mine it to the Moon, otherwise it's a net
loss.

Simply put, if you're going to extract say 100 kilotons of fuel from the
Moon, you're going to have to use less than 100 kilotons of fuel getting
your mining and processing equipment there, otherwise it's a waste.


Perhaps you on purpose ignored this factor in your approximation, but
surely the *location* of the fuel must be considered?

If you use 100 kilotons of fuel to send equipment to the Moon, most of
that fuel is used up close to the Earth, and will not reach the Moon. If
that equipment then produces 100 kilotons of fuel on the Moon, that fuel
is on the Moon, which is "half-way to anywhere".

You would surely have to use *much* more than 100 kilotons of fuel to
deliver a payload of 100 kilotons of fuel from the Earth's surface to
the Moon's surface.


So let's revise the original statement a bit. If the goal is to refuel
a depot in lunar orbit, the fuel you mine, refine, and launch to that
depot must exceed the amount of fuel it took to originally land the
mining equipment, lander, and landing fuel when starting from roughly
the same lunar orbit as the depot.


I agree with that.

Ignore the delta-V to get to lunar
orbit, because it's the same for the 100 kilotons of fuel put in lunar
orbit or the 100 kilotons of lunar lander, fuel, and mining equipment
put in lunar orbit.


How did you get from Greg's assumed "100 kilotons of fuel getting your
mining and processing equipment there [to the Moon]" to "100 kilotons of
lunar lander" etc.?

The original statement assumed 100 kilotons of fuel would be used, in
total, for transporting the mining equipment from (presumably) the
Earth's surface to the Moon. The mass of that equipment, including
whatever is needed to bring it from lunar orbit to the lunar surface,
must then be assumed to be *much* less than 100 kilotons.

--
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
. @ .
  #18  
Old June 7th 17, 05:58 PM posted to sci.space.policy
Niklas Holsti
external usenet poster
 
Posts: 60
Default Mining the moon for rocket fuel to get us to Mars

On 17-06-05 16:09 , Greg (Strider) Moore wrote:
"Niklas Holsti" wrote in message ...

On 17-06-05 04:06 , Greg (Strider) Moore wrote:
"Jeff Findley" wrote in message
...

First, this isn't my "subject", it's the title of this article:

Mining the moon for rocket fuel to get us to Mars
May 14, 2017 8.04pm EDT ?Updated May 18, 2017 9.01am EDT
http://theconversation.com/mining-th...-to-get-us-to-

mars-76123

I saw this article (or a variation of it from another online
publication) on Twitter. I replied something to the effect that this
article glosses over all of the hard stuff, like the fact that the
lunar
soil and rock is horribly abrasive and that mining equipment isn't
anything like the lightweight rovers that NASA/JPL has flown in the
past.


[snip]

Don't get me wrong, I think *eventually* we'll be mining the moon for
water to turn into LOX and LH2 (or possibly methane) to supply a fuel
depot in lunar orbit. But, needless to say, I think the supporters of
this notion are daft if they think it's going to happen in the next 20
years or so by building a freaking factory on the moon that's
capable of
building mining equipment that's not JPL class "toys" that wear out
faster than you can build them.

Jeff

Yeah, I use a very simple first order approximation for this:
the mass of the fuel you'll get from the Moon has to be greater than
fuel used to get the mass to mine it to the Moon, otherwise it's a net
loss.

Simply put, if you're going to extract say 100 kilotons of fuel from the
Moon, you're going to have to use less than 100 kilotons of fuel getting
your mining and processing equipment there, otherwise it's a waste.


Perhaps you on purpose ignored this factor in your approximation, but
surely the *location* of the fuel must be considered?

If you use 100 kilotons of fuel to send equipment to the Moon, most of
that fuel is used up close to the Earth, and will not reach the Moon.
If that equipment then produces 100 kilotons of fuel on the Moon, that
fuel is on the Moon, which is "half-way to anywhere".

You would surely have to use *much* more than 100 kilotons of fuel to
deliver a payload of 100 kilotons of fuel from the Earth's surface to
the Moon's surface.


Not that much more really. And as I said, it's a first order
approximation. There's a lot more math involved than simply this.


No kidding :-)

But if you figure the delta V just to get to the Moon is approximately
12.52km/sec, and the delta-V from lunar transfer to surface is probably
about 2.55, and 2.55 back out, so that's less than 1/2.


What goes to the Moon (12.52 + 2.55 km/sec) is the mining and
fuel-producing equipment. If that trip uses 100 kilotons of fuel, most
of that is used near Earth (not close to the Moon) and the final part
(landing, 2.55 km/s) is for a much smaller mass.

Sure, you can probably play some numbers there (direct impact, etc.)


Not my point at all. My point is just the ratio of fuel weight to
payload weight, which is large for a trip from the Earth's surface to
lunar orbit or lunar surface, whether you are sending fuel or mining
equipment.

If you are sending fuel, to be stored in lunar orbit, there is the
advantage that it does not have to be landed onto the lunar surface,
unlike the mining equipment. But the ratio between the delta-vees (12.52
vs 2.55 km/s) means that the landing cost is relatively small.

Again as a first order approximation, figure the energy used to land
will be about the same as taking off.


What lands is the mining equipment, which must mass much less than 100
kilotons, if it took only 100 kilotons of fuel to send it from the Earth
to the Moon. What takes off is the fuel that is produced (assumed to be
100 kilotons), plus whatever containers and propulsion it needs. So the
take-off uses much more energy.

(Plus one can potentially use electromagnetic launchers for launching
the fuel from the lunar surface to lunar orbit, so the overhead in terms
of containers and propulsion could be small.)

Now, figure if you want to go to Mars, from lunar transfer to Mars is
approximately less than landing on the Moon, especially if you can use
some aerobraking.


Right, which is why fuel in lunar orbit is so valuable, compared to fuel
on the Earth.

--
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
. @ .
 




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