Moon Base L2 for Solar Sail Assembly Line

"Jeff Findley" wrote in message
...

In article ,
says...
space xs lower cost to orbit may make doing things on cite more costly

I have no idea what you are talking about.

I'm going to attempt to translate.

I assume cite should be site.

I assume space xs refers to a company we all call SpaceX.

Starting with that, I think Bob is trying to say that if launch costs drop
enough, it won't be worth it economically to do things on-site, such as
manufacturing on the Moon or the like.

The problem he's overlooking (and honestly far too many in my opinion) is
that it's a chicken and egg problem.
The argument for say, mining the Moon for rocket fuel is that launch costs
are too high. But, those arguing that often overlook the massive amount of
equipment required to mine the Moon in the first place. So you're spending a
LOT of money to launch stuff to the Moon to make stuff cheaper than if you
launched it from the Earth. Or something like that.

So, Bob is trying to claim if you can launch from the Earth cheaper, it's
less economical to do stuff on-site on the Moon.
He's both right and wrong. He's sort of right, because until you have the
need for a very large industrial complex, the economics of on-site just
don't work. And this makes the economics of Earth launch cheaper. He's
wrong also because now the cost of your large industrial complex also drops
meaning it can become more economical at smaller usage levels.

Of course I know you know this, but I'm sure Bob missed the latter point and
many miss both.


Jeff

--
Greg D. Moore http://greenmountainsoftware.wordpress.com/
CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net

In article ,
says...

"Jeff Findley" wrote in message
...

In article ,
says...
space xs lower cost to orbit may make doing things on cite more costly

I have no idea what you are talking about.

I'm going to attempt to translate.

I assume cite should be site.

I assume space xs refers to a company we all call SpaceX.

Starting with that, I think Bob is trying to say that if launch costs drop
enough, it won't be worth it economically to do things on-site, such as
manufacturing on the Moon or the like.

The problem he's overlooking (and honestly far too many in my opinion) is
that it's a chicken and egg problem.
The argument for say, mining the Moon for rocket fuel is that launch costs
are too high. But, those arguing that often overlook the massive amount of
equipment required to mine the Moon in the first place. So you're spending a
LOT of money to launch stuff to the Moon to make stuff cheaper than if you
launched it from the Earth. Or something like that.

So, Bob is trying to claim if you can launch from the Earth cheaper, it's
less economical to do stuff on-site on the Moon.
He's both right and wrong. He's sort of right, because until you have the
need for a very large industrial complex, the economics of on-site just
don't work. And this makes the economics of Earth launch cheaper. He's
wrong also because now the cost of your large industrial complex also drops
meaning it can become more economical at smaller usage levels.

Of course I know you know this, but I'm sure Bob missed the latter point and
many miss both.

We just don't know yet how expensive in situ resource utilization will
be. That said, there are a lot of resources "out there" that are in
gravity wells that are a lot more shallow than earth. It's only a
matter of time until it's cheaper and easier to start utilizing those
resources. How much time is an open ended question.

But, we certainly won't find the answers to those questions if we stick
to the all expendable Apollo/Saturn paradigm forever out of timidity,
risk aversion, or whatever it is that is paralyzing NASA's upper
management into making mission proposals like bringing an ever shrinking
piece of an asteroid to the earth-moon system for an astronaut to
examine rather than simply sending astronauts to the freaking asteroid.

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.

On Thursday, February 11, 2016 at 6:25:57 AM UTC-5, Jeff Findley wrote:
In article ,
says...

"Jeff Findley" wrote in message
...

In article ,
says...
space xs lower cost to orbit may make doing things on cite more costly

I have no idea what you are talking about.

I'm going to attempt to translate.

I assume cite should be site.

I assume space xs refers to a company we all call SpaceX.

Starting with that, I think Bob is trying to say that if launch costs drop
enough, it won't be worth it economically to do things on-site, such as
manufacturing on the Moon or the like.

The problem he's overlooking (and honestly far too many in my opinion) is
that it's a chicken and egg problem.
The argument for say, mining the Moon for rocket fuel is that launch costs
are too high. But, those arguing that often overlook the massive amount of
equipment required to mine the Moon in the first place. So you're spending a
LOT of money to launch stuff to the Moon to make stuff cheaper than if you
launched it from the Earth. Or something like that.

So, Bob is trying to claim if you can launch from the Earth cheaper, it's
less economical to do stuff on-site on the Moon.
He's both right and wrong. He's sort of right, because until you have the
need for a very large industrial complex, the economics of on-site just
don't work. And this makes the economics of Earth launch cheaper. He's
wrong also because now the cost of your large industrial complex also drops
meaning it can become more economical at smaller usage levels.

Of course I know you know this, but I'm sure Bob missed the latter point and
many miss both.

We just don't know yet how expensive in situ resource utilization will
be. That said, there are a lot of resources "out there" that are in
gravity wells that are a lot more shallow than earth. It's only a
matter of time until it's cheaper and easier to start utilizing those
resources. How much time is an open ended question.

But, we certainly won't find the answers to those questions if we stick
to the all expendable Apollo/Saturn paradigm forever out of timidity,
risk aversion, or whatever it is that is paralyzing NASA's upper
management into making mission proposals like bringing an ever shrinking
piece of an asteroid to the earth-moon system for an astronaut to
examine rather than simply sending astronauts to the freaking asteroid.

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.

the desion to bring the asteroid to a close by location for exploration may be a budget driven one.

bring the asteroid close by.

requires a propulsin stage, possibly very low thrust, that would fire a long time

now taking humans to deep space. nasa claims SLS is required. its just another attempt to try and justify spending a billion bucks on each booster, plus the costs of payload.
so likely 5 billion
will require a habitat, and supplies for along time.

plus they would be far from earth in a emergency....

its just a repackaged pork piggie

On Sunday, February 7, 2016 at 7:53:20 PM UTC-5, wrote:
Moon Base L2
Douglas Eagleson


I read somewhere that L2 was to be usable for launching solar sails. L2 is the geostationary
lagrangian point on the far side of the moon.

I was rumaging the issue. L2 exhibits a well like location behavior. An object placed there tends to settle.


Just to reiterate. moonbase L2 has an odd surface gravity well also when the L2 field exists. There is a clear launching field so ultralight sails can be lofted during valid launch window. I am talking about 100 pound, 5x5 km square target value for the interstelloar version. One mil mylar is to be used.The X'ed cross structural frame poles are the designs critical need.

The basic physics to understand is the L2 field. Stability well goes to the moon's surface. ergo moonbase L2

I tried one time to get National Geographic funding to do a geophysical survey of the high speed moon spot on the earth's surface. The exact moon high noon spot has never been measured before either. Gravity, time,gps location, air color,etc were to be setup at the predicted high noon and a computer would fire off highspeed data recorders. I was to be the logistical manager and get a Phd to do the science.

On Wednesday, February 10, 2016 at 5:55:35 AM UTC+13, Jeff Findley wrote:
In article . com,
says...

L4 is also a good point to launch solar sails. Or is it?

Since there isn't even a McDonalds there, what is the point of staging a
launch at a LaGrange point since you'll need to spend fuel to get there,
so there are no real savings and no resources there. And bring supplies
there will cost a lot more fuel, and any EVA there also has the
radiation problem since you're above Van Allen.

Setting aside the issue of lack of a stable point or orbit around L2 for
a moment...

Please don't set ot asode! Because doing so presumes your prejudices in this matter is settled science. It is not!

FIrst off, L4 and L5 are stable, which was why they were proposed places for a colony.

http://farside.ph.utexas.edu/teachin...l/node126.html

Lagrange Point 1,2,3 are mildly unstable, in the same way balancing a broom on your hand is unstable. Yet, Segway and Honda powered unicycles are decades old, and the problem isn't very hard by today's standards.

https://www.youtube.com/watch?v=IH4EZ1GCrK0
https://www.youtube.com/watch?v=WIsPTFcoF6c

The only question we have is;

(1) what is the thrust level to maintain one's position,
(2) what is the delta vee required to maintain one's position,
(3) what is the specific impulse achievable?

The answer is 0.3715 km/s per year! That's the answer to (2). Dividing by the number of seconds in a year we have 1.2 micro-gees (11.77 mm/sec/sec.) that's the answer to (1). Using PLT - photonic laser thruster - specific impulse is infinity! Requiring no propellant! Putting the laser at L4 and L5 and beaming solar pumped laser energy to L1, L2 and L3 does the trick. The power levels are modest. Further, laser energy beamed from one Lagrange point to another, provides back up power in the rare instances the sun is eclipsed by the Earth or Moon.

A common way to measure the instability is to calculate its "e-folding" number. The E-folding number is the time required for the positional error to grow by a factor of e or Euler's number (2.718...). Solving for t for the Sun-Earth-Moon system yields an L1 & L2 e-folding number of ~23days, while L3 is ~150 years! This is the reason L3 is called quasi-stable.

http://ccar.colorado.edu/asen5050/pr...ts_2003/jones/

The resulting time constants for L1 & L2 are ~ 1.59 days and L3 ~ 58.7 days..

(notice the studies are over a decade old! So, this isn't new! Anyone who knows their salt understands this. Anyone who doesn't, doesn't.)


If you're using materials (including fuel and oxidizer) obtained from
the moon, there could be an advantage because the moon's gravity is far
less, so it ought to take much less delta-V to take materials from the
lunar surface to L2 than from the earth's surface to L2.

Correct! This has all been studied extensively by NASA itself.

https://www.nasa.gov/pdf/140635main_ESAS_04.pdf

And is still seriously being developed by those who are leaders in the aerospace community;

http://au.ign.com/articles/2016/01/2...r-construction

This takes no propellant.

http://arc.aiaa.org/doi/abs/10.2514/3.28009
http://arc.aiaa.org/doi/abs/10.2514/...ournalCode=jsr

Combining this technology with PLT from Young Bae, provides a means to send products extracted from the Moon to any of the Lagrange Points and keep them there.


In LEO, you have a constant sun/dark cycle every 90 minutes.

Not if you're in Sun Synchronous Polar Orbit whose plane is normal to the Sun's center. You'll never see the Sun set then.

https://en.wikipedia.org/wiki/Sun-synchronous_orbit

This lets
you charge batteries and then cool down 45 minutes later when it goes dark.

This also creates all sorts of cyclic thermal stresses to deal with. It
also means you need fairly heavy batteries to store electricity when
your solar arrays are in darkness. Plus, if you assemble a frail craft
like a solar sail in LEO, getting it out of LEO and through the van-
Allen radiation belts quickly is a problem.

What sort of orbital periods are we talking about at LaGrange ?

??? The answer is obvious! Stop and think about it for a minute.

The Earth Moon lagrange points all are fixed relative to the Earth Moon system, so the corresponding orbital period of 27.3 days relative to the Earth. The moon takes 29.5 days to return to the same point on the celestial sphere as referenced to the Sun because of the motion of the Earth around the Sun; this is called a synodic month (Lunar phases as observed from the Earth are ...relative to the center of the Earth, the objects at those points orbit with the same period as the moon, just at different phases.

What
percentage of time is spent in the dark vs sun ? Would there be issues
with cooling (long periods of sun) or battery autonomy (long periods of
dark) ?

The objects at the Lagrange Points are eclipsed as often as the Moon suffers a lunar eclipse. One calendar year has a minimum of four eclipses - two solar eclipses and two lunar eclipses. Most years - such as 2015 - have only four eclipses, although you can have years with five eclipses (2013, 2018 and 2019), six eclipses (2011 and 2020) or even as many as seven eclipses (1982 and 2038).

Two lunar eclipses at each Lagrange point lasting no more than 3 hr 40 minutes. So, the solar panels operate 99.916% of the time!

Put it in a halo orbit around L2 and you'd have virtually no periods of
darkness.

Virtually no periods of darkness anywhere within 1,738 km of ANY Lagrange point. For the 3h 40 minutes twice a year when its dark, you can use back up solar laser from another Lagrange point, still in sunlight.

People have thought about these things and written papers on
the subject:

A Lunar L2 Navigation, Communication, and Gravity Mission
Keric Hill, Jeffrey Parker, George H. Born, and Nicole Demandante
University of Colorado, Boulder, Colorado 80309
http://ccar.colorado.edu/geryon/pape...AA-06-6662.pdf

Jeff

They've also written papers about the stability of the points as well, and how easy it is to keep things in place. I guess that's why you wanted to say dismissive things and then set it aside, since your dismissive statements have no reality in back of it.

--
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.

On Wednesday, February 10, 2016 at 6:07:27 AM UTC+13, Rick Jones wrote:
Jeff Findley wrote:
Plus, if you assemble a frail craft like a solar sail in LEO,
getting it out of LEO and through the van- Allen radiation belts
quickly is a problem.

Are materials commonly considered for solar sails that sensitive to
radiation, or is it more just a slow trip through the belts in general
and the effects on the electronics whether the propulsion was solar
sail or not?

rick jones

http://www.nepp.nasa.gov/docuploads/...g_Space-00.pdf

http://ntrs.nasa.gov/archive/nasa/ca...9710020300.pdf

Dupont has quoted 120,000 hours for their solar films for space applications. Around 14 years.


--
a wide gulf separates "what if" from "if only"
these opinions are mine, all mine; HPE might not want them anyway...
feel free to post, OR email to rick.jones2 in hpe.com but NOT BOTH...

https://www.youtube.com/watch?v=T01i_vp2mJE
https://en.wikipedia.org/wiki/Polyet..._terephthalate

Mylar is made from aluminium and PET plastic. Modern GBO film is made of PET alone. Advanced conjugate optic mirrors uses GBO film patterned with microscopic retroreflectors.

PET is polyethylene terephthalate which is produced from ethylene glycol (HO–CH2CH2–OH) and dimethyl terephthalate (C6H4(CO2CH3)2) or terephthalic acid.

Ethylene glycol is produced from ethylene (ethene), via the intermediate ethylene oxide. Ethylene oxide reacts with water to produce ethylene glycol according to the chemical equation:

C2H4O + H2O → HO–CH2CH2–OH

So, we basically have carbon, hydrogen and oxygen. Oxygen is plentiful on the moon, and water is also broadly available near the poles, according to Chinese and Indian lunar satellite data. They have also found copious quantities of carbon on the moon as well, distinctly different than the reports of Apollo and Lunar Orbiter findings.

http://www.thehindu.com/sci-tech/sci...icle842838.ece

Making polymers is only the begining. Stretching polymers produces polarisation in the materials by orienting the molecules in the material. So, taking a cylinder of material and stretching it after melting, orients molecules in the direction of the extension, thinning the cylinder walls. Inflating the thin walled cylinder into a sphere is well defined process, understood by anyone who has blown a spherical balloon up using a cylindrical deflated balloon.

http://www.engr.uvic.ca/~struchtr/2002balloons.pdf

PET softened by solar energy may be extruded into a thin walled cylinder, by pressing, and then inflated to form a large highly reflective sphere.

https://www.youtube.com/watch?v=CXDD07DA01s

A 10 km diameter sphere that is 4 um thick contains 1256.64 cubic meters of plastic massing 1721.60 metric tons of PET. Made of 121 layers each 33 nm thick, 121 pellets 909 mm diameter by 1,455 mm long pellet, launched by a mass driver, from a factory that extracts CO2 and H2O to make the stuff on the moon's pole. Each pellet is then extruded into a variable thickness tube 1 km long, and inflated at very low pressure in vacuo with CO2 and H2O extracted from the PET itself. (about 0.01% of the mass). A 10 ton factory layers the birefringent films against one another. Swarms of micro-robots operate on both sides of the gas envelope to pinch it and form it on the microscale, very accurately shaping it to produce the desired optical effects, localling heating spots to reduce birefringence and reflectivity in the process.

https://www.youtube.com/watch?v=xK54Bu9HFRw

A 10 km diameter sphere may be rendered into any number of shapes, intercepting 107.47 GW of solar power at 1 AU from Sol, or more, yielding 62.4 kW/kg.

http://www.lgarde.com/assets/content...ns/scaling.pdf
http://www.lgarde.com/assets/content...ons/concen.pdf
http://digitalcommons.usu.edu/cgi/vi...ntext=smallsat

A small 100 ton factory processing one ton of PET per minute, requires 153.4 MW of power to process the CO2 and H2O into PET. This is enough to produce 1.2 solar collectors every 24 hours, that generates useful energy at a rate of 107.47 GW.

To impart 2.62 km/sec to 1 metric tons requires 3.43 GJ, so in a minute this adds another 57.2 MW. A total of 210.6 MW of power. Less than 0.2% of the output of a single 10 km system.

http://www.russianspaceweb.com/lagrange.html

After deploying one power satellite at each of the Lagrange Points, over a four day period we then use photonic thrusters to impart 3.47 km/sec to the power sats - to bring them into GEO. At 107.47 GW per satellite, and 1.2 satellites per day, we deploy 438 satellites in one year, which is sufficient to power the Earth at substantially higher levels than we use energy today. In only 18 months we deploy enough satellites, 658, to allow every man woman and child consume energy at the rate of the average American (9.6 kW). In 36 months we double this rate. 70.4 x 2 = 140.8 trillion watts.

Using a solar pumped laser to energise propellant to 9.2 km/sec to send a SSTO to LEO means that for every kg sent into space in this way, 0.8 kg of structure is required and 3.2 kg of propellant is required. The 1.8 kg on orbit is then pushed by PLT with no added propellant, across the solar system at 1/10th gee. Accelerating 3.2 kg of propellant to a speed of 9.2 km/sec requires 135.4 MJ of energy. Dividing this into two, with half going to consumption, whilst the other half, 70.4 TW of power, goes to laser launchers, obtains 519.7 metric tons per second. That's 16.4 billion tons per year. Over two tons per person alive today. 1,100 kg per person combined with 800 kg of spacecraft.

We could depopulate the world with a programme that lasts less than five years. One year to design and deploy the production system. Three years to deploy the power satellites. One year to launch all the people off world.

Everyon's gone to the moon!

https://www.youtube.com/watch?v=qvtHLkdRE2Y


The bulk of humanity leaving a dying world, bursting into a new recently discovered world, evokes feelings captured in this 1965 song;

Ferry Cross the Mersey is a 1965 musical film featuring Gerry and the Pacemakers, shuttle crossing cislunar space to the moon.

Scenes were shot in clubs near the home of Gerry and the Pacemakers' frontman Gerry Marsden. A scene on a ferry (the Mountwood) on the River Mersey showed the docks as a backdrop. Marsden wrote nine new songs for the film which also starred Julie Samuel, Cilla Black singing "Is it Love?". Future Doctor Who actress Elisabeth Sladen appeared in the film as an uncredited extra.

The song "Ferry Cross the Mersey" was written by Gerry Marsden as the theme song for the film.

As of March 2014, the film has never seen a commercial release. Neil Aspinall owned the rights to the movie in the past before his death.

https://www.youtube.com/watch?v=08083BNaYcA

Connie Stevens - I Can't Say No! - 1962;

https://www.youtube.com/watch?v=rEhgboaFaEs

What connection has that with the moon?

The first man on the moon!

https://goo.gl/gsiUAa

Neil Armstrong went to Bob Hope's Sixth Vietnam Christmas show in 1969 along with Frank Borman. Connie Stevens just broke up with Eddie Fisher a few months earlier, and apparently hooked up with Neil on the trip back to the States from Vietnam, according to Hollywood insiders.

More hookups to follow as we develop the technology off world that allow it and billions follow suit.

https://www.youtube.com/watch?v=5M5i39lGo-E
https://www.youtube.com/watch?v=g3yfGECZuCk

Wanderers is a vision of humanity's expansion into the Solar System, based on scientific ideas and concepts of what our future in space might look like, when it happens.

https://www.youtube.com/watch?v=YH3c1QZzRK4

It starts here and now, moves to the moon, and its environs, and moves beyond. To Mars the asteroids, and then to the planets and stars beyond the inner solar system.

http://ntrs.nasa.gov/search.jsp?R=19780044024

Demandite involves taking found and spent materials and reducing them to elemental forms, and then re-assembling them into useful products and materials. This takes 40 MJ/kg of material. So, the aforementioned 107 GW of power per unit man 9,630 metric tons per hour is processed. 84.4 million tons per year. Now, a person uses about 1 ton per year which means each station supports 84.4 million people. Since each station masses 1716 tons, and the self replicating machinery masses 1000 tons, we have a replication time of 20 minutes.

On Wednesday, March 2, 2016 at 9:42:28 PM UTC+13, William Mook wrote:
http://ntrs.nasa.gov/search.jsp?R=19780044024

Demandite involves taking found and spent materials and reducing them to elemental forms, and then re-assembling them into useful products and materials. This takes 40 MJ/kg of material. So, the aforementioned 107 GW of power per unit man 9,630 metric tons per hour is processed. 84.4 million tons per year. Now, a person uses about 1 ton per year which means each station supports 84.4 million people. Since each station masses 1716 tons, and the self replicating machinery masses 1000 tons, we have a replication time of 20 minutes.

http://hyperphysics.phy-astr.gsu.edu...ics/lagpt.html

Microscopic devices that self replicate mimic living systems in many respects, excepting those that make use of silicide (a silicon analogue of graphene) can 'grow' anywhere! From a space developer's perpsective, this means that very small payloads can grow into significant capabilities in very short times.

Nanoscale structures on crystalline surfaces of silicon make modern electronics possible. Creating nanoribbons of 2d patterns of silicon

http://www.nanowerk.com/spotlight/spotid=24693.php
http://www.eetimes.com/document.asp?doc_id=1322256

and folding them into a variety of shapes

https://www.youtube.com/watch?v=VQXKgG7tsII

to create machines

https://www.youtube.com/watch?v=ZVYz7g-qLjs

that make other machines

https://www.youtube.com/watch?v=ZX-iJLHZt8M
https://www.youtube.com/watch?v=ihR9SX7dgRo
https://www.youtube.com/watch?v=FZTsWEfnqtg

I have been working on machine cells that are 6 micron thick shells that are 230 microns in diameter. They are solar powered, and use any reasonable source of silicon to make copies of itself. A 300 mm wafer may be patterned with 1.7 milion shapes that fold up into 1.7 million functional cells.

Each cell weighs 6.4 nanograms and intercepts 56.8 microwatts of sunlight on the moon's surface, which it converts with 80% efficiency to useful work. 45.5 microwatts net output, available for processing rocks into more cells.

Dividing 45.5 microwatts by 6.4 nanograms obtains 8.9 kilowatts per gram! 8.9 MW/kg. Now with 40 MJ/kg energy cost in additively assembling chemicals extracted from rock that is 27.7% silicon, it takes 16.2 seconds for a cell to self replicate from 23.1 nanograms of rock. In less than 8 minutes, a single cell grows to 1 gram. In 10 minutes, this grows to 1 kilogram. In less than 16 minutes, this grows to 1,000 metric tons.

What can you do with lots of microscopic machine cells?

Assemble things out of them! Just as multi-celled organisms are formed from patterns of cooperating cells, so too are multi-celled machines possible.

https://www.youtube.com/watch?v=dDsmbwOrHJs
https://www.youtube.com/watch?v=ZXpkG93KzdY

So, what's the minimum system required to put something like this on the moon?

Consider the advances produced by Myrabo's Lightcraft

https://www.youtube.com/watch?v=5_9ac-w4DW8

combined with Infineon's thin film power mosfet technology adapted toward the purposes outlinded here;

http://www.eetimes.com/document.asp?doc_id=1280471

A ten wafer system, each wafer 7 microns thick, masses only 12.8 grams together, and containing in unfolded form, a single 7 micron payload layer that folds into 1.7 million cells upon receiving a signal, and then 'eats' the pure silicon 'ship' to get started - growing to 2 billion cells before spreading to the surrounding environment!

SPACE PROPULSION

http://lmts.epfl.ch/MEMS-ion-source

A laser energised jet that accelerated to 3.2 km/sec that switched to a laser energised rocket that accelerated to an added 9 km/sec, and then used a laser energised rocket to slow to a landing on the moon's surface imparting a delta vee of 3 km/sec.

LUNAR LANDING

Producing 1/2 gee at the moon to impart 3 km/sec using a 9 km/sec exhaust speed. 12.8 grams spacecraft with 300 mm diameter receiver. It carries 5 grams of working fluid to achieve this. Moving at 9 km/sec 5 grams contains 202.5 kilojoules. At 1/2 gee, it takes 611.83 seconds to impart 3 km/sec delta vee. So, this implies a 331 Watt power level for the exhaust jet. 9.7 micrograms of propellant per second to produce 87.3 millinewtons of force. This is only a small part of the 20 kW laser beamed from Earth using a 4 m diameter thin film adaptive reflector.

UPPER STAGE

With a 6 km/sec exhaust speed to produce a 9 km/sec delta vee requires that an additional 62 grams of propellant. About the size of a super-large inkjet cartridge. The propellant is a layer of material only 1 mm thick, between the wafer layers described earlier.

At two gees it requires 458.9 seconds to impart 9 km/sec. 62 grams moving at 9 km/sec contains 1.116 MJ. The power level to achieve this performance totals 2.5 kW. The distance over which it accelerates at right angles to the Earth's center is 2,065.2 km.

FIRST STAGE

The electrospray system that imparts thrust from the 62 grams of propellant, forms an annulus around a laser receiver/transmitter at the base of the vehicle. At lift off and in the lower atmosphere, the system uses air as a working fluid rather than propellant stored on board. The air is ejects at 6 km/sec and so has the same power level as the upper stage, but the acceleration is largely vertical, so, it requires 326.3 seconds to accelerate to 3.2 km/sec. It moves straight up 52 km before heading off at right angles toward its trajectory to the moon and travelling another 430 km downrange before switchin on the propellant flow. At that point is is 7 degrees above the horizon relative to the launch center. For this reason, several telescopes with 20 kW laser beams and adaptive optics beam energy to the spacecraft.

AEROSHELL

The wafer stack is surrounded by an aerogel filling forming an aeroshell to give the system lifting properties, while inducing air flow into the MEMS jets. Meanwhile the MEMS electrospray rockets cover the rim in a way that allows switching between elements to change direction of thrust relative to the wafer receiver and CG. So, the disk rises vertically over the launch laser and has the ability to change thrust vector relative to the receiver so that angle of attack can vary in ways that reduce drag, and maintain optimal flight path and energy reception.

MAX Q

40 seconds after launch, at 5.9 km altitude, thrust is reduced to maintain subsonic speeds until air density is reduced rising to an altitude of 52 km over the next three minutes. An appropriate level to maintain conditions. At a distance of 215 km from the launch point the device is 14 degrees above the horizon at both the launch center and 14 degrees above the horizon at a point 430 km away where a second 20 kW laser operates. By the time the vehicle is overhead of the downrange facility, it is 7 degrees above the horizon from the launch center, and begins climbing in altitude along a trajectory to the moon. Because of the shape of the Earth and its rotation, relative to this trajectory, the vehicle is 3 degrees above the horizon of the downrange laser when it achieves Trans Lunar Injection speed.

Terminal velocity is chosen so that the vehicle is 30 degrees above the horizon when lunar landing is to take place and rising. There is only a slight 4 degree variation between the two lasers, and having two lasers gives some backup.


AFTER LANDING

Upon settling down on the lunar surface, a 300 mm diameter wafer with the sun directly overhead, receives 97 watts of solar energy and at 80% efficiency, generates 77.4 watts from sunlight. Now, the ability to send a laser beam that energises the same wafer to 331 watts, with nearly 100% efficiency, provides an efficient start to the replication process! Within 15 minutes a ton of machine cells spreads from the landing point forming a dark spot some 16 meters in diameter.

UTILITY FOG

The laser beam now acts as a command and control system for the growing population of machine cells on the moon. Well before the sun sets at the landing point, the entire lunar surface has been processed to a depth of several meters, creating an array of lunar bases.

LUNAR MAGLEV & LUNAR LAUNCHERS

A 300 km lunar maglev that accelerates payloads at one gee has the ability to project objects from the lunar surface, or slow objects arriving at lunar escape velocity, if they are well aimed and guided. A network of maglev tracks also operate to transport objects anywhere on the lunar surface.

L4 and L5 SOLAR POWER STATIONS

Materials processed and then ejected from the lunar surface and use laser powered ion rockets powered from lunar surface, to stop at L4 and L5. This allows the assembly of massive power stations a L4 and L5 that are used to propel ships launched from the moon deeper into space.

GEO SOLAR POWER STATIONS

Materials processed and then ejected from the lunar surface and use laser powered ion rockets powered from L4 and L5, to enter GEO orbits around Earth.. This allows the assembly of massive power stations at GEO, that are used to propel ships launched from Earth into orbit and beyond.

https://www.youtube.com/watch?v=8xy6YKTu51c

ASTEROIDS

Accelerating at 2 gees for a distance of 996 km attains a speed of 6.25 km/sec - which is sufficient to carry a well aimed payload from Earth Orbit to the asteroid belt in 38 weeks. Once there, similar processes take place there to process asteroids into useful products. Speeds are 1/6th the rate because sunlight is only 220 W/m2 instead of 1368 W/m2.

On Tuesday, March 8, 2016 at 3:08:03 PM UTC+13, William Mook wrote:
On Wednesday, March 2, 2016 at 9:42:28 PM UTC+13, William Mook wrote:
http://ntrs.nasa.gov/search.jsp?R=19780044024

Demandite involves taking found and spent materials and reducing them to elemental forms, and then re-assembling them into useful products and materials. This takes 40 MJ/kg of material. So, the aforementioned 107 GW of power per unit man 9,630 metric tons per hour is processed. 84.4 million tons per year. Now, a person uses about 1 ton per year which means each station supports 84.4 million people. Since each station masses 1716 tons, and the self replicating machinery masses 1000 tons, we have a replication time of 20 minutes.

http://hyperphysics.phy-astr.gsu.edu...ics/lagpt.html

Microscopic devices that self replicate mimic living systems in many respects, excepting those that make use of silicide (a silicon analogue of graphene) can 'grow' anywhere! From a space developer's perpsective, this means that very small payloads can grow into significant capabilities in very short times.

Nanoscale structures on crystalline surfaces of silicon make modern electronics possible. Creating nanoribbons of 2d patterns of silicon

http://www.nanowerk.com/spotlight/spotid=24693.php
http://www.eetimes.com/document.asp?doc_id=1322256

and folding them into a variety of shapes

https://www.youtube.com/watch?v=VQXKgG7tsII

to create machines

https://www.youtube.com/watch?v=ZVYz7g-qLjs

that make other machines

https://www.youtube.com/watch?v=ZX-iJLHZt8M
https://www.youtube.com/watch?v=ihR9SX7dgRo
https://www.youtube.com/watch?v=FZTsWEfnqtg

I have been working on machine cells that are 6 micron thick shells that are 230 microns in diameter. They are solar powered, and use any reasonable source of silicon to make copies of itself. A 300 mm wafer may be patterned with 1.7 milion shapes that fold up into 1.7 million functional cells.

Each cell weighs 6.4 nanograms and intercepts 56.8 microwatts of sunlight on the moon's surface, which it converts with 80% efficiency to useful work. 45.5 microwatts net output, available for processing rocks into more cells.

Dividing 45.5 microwatts by 6.4 nanograms obtains 8.9 kilowatts per gram! 8.9 MW/kg. Now with 40 MJ/kg energy cost in additively assembling chemicals extracted from rock that is 27.7% silicon, it takes 16.2 seconds for a cell to self replicate from 23.1 nanograms of rock. In less than 8 minutes, a single cell grows to 1 gram. In 10 minutes, this grows to 1 kilogram. In less than 16 minutes, this grows to 1,000 metric tons.

What can you do with lots of microscopic machine cells?

Assemble things out of them! Just as multi-celled organisms are formed from patterns of cooperating cells, so too are multi-celled machines possible.

https://www.youtube.com/watch?v=dDsmbwOrHJs
https://www.youtube.com/watch?v=ZXpkG93KzdY

So, what's the minimum system required to put something like this on the moon?

Consider the advances produced by Myrabo's Lightcraft

https://www.youtube.com/watch?v=5_9ac-w4DW8

combined with Infineon's thin film power mosfet technology adapted toward the purposes outlinded here;

http://www.eetimes.com/document.asp?doc_id=1280471

A ten wafer system, each wafer 7 microns thick, masses only 12.8 grams together, and containing in unfolded form, a single 7 micron payload layer that folds into 1.7 million cells upon receiving a signal, and then 'eats' the pure silicon 'ship' to get started - growing to 2 billion cells before spreading to the surrounding environment!

SPACE PROPULSION

http://lmts.epfl.ch/MEMS-ion-source

A laser energised jet that accelerated to 3.2 km/sec that switched to a laser energised rocket that accelerated to an added 9 km/sec, and then used a laser energised rocket to slow to a landing on the moon's surface imparting a delta vee of 3 km/sec.

LUNAR LANDING

Producing 1/2 gee at the moon to impart 3 km/sec using a 9 km/sec exhaust speed. 12.8 grams spacecraft with 300 mm diameter receiver. It carries 5 grams of working fluid to achieve this. Moving at 9 km/sec 5 grams contains 202.5 kilojoules. At 1/2 gee, it takes 611.83 seconds to impart 3 km/sec delta vee. So, this implies a 331 Watt power level for the exhaust jet. 9.7 micrograms of propellant per second to produce 87.3 millinewtons of force. This is only a small part of the 20 kW laser beamed from Earth using a 4 m diameter thin film adaptive reflector.

UPPER STAGE

With a 6 km/sec exhaust speed to produce a 9 km/sec delta vee requires that an additional 62 grams of propellant. About the size of a super-large inkjet cartridge. The propellant is a layer of material only 1 mm thick, between the wafer layers described earlier.

At two gees it requires 458.9 seconds to impart 9 km/sec. 62 grams moving at 9 km/sec contains 1.116 MJ. The power level to achieve this performance totals 2.5 kW. The distance over which it accelerates at right angles to the Earth's center is 2,065.2 km.

FIRST STAGE

The electrospray system that imparts thrust from the 62 grams of propellant, forms an annulus around a laser receiver/transmitter at the base of the vehicle. At lift off and in the lower atmosphere, the system uses air as a working fluid rather than propellant stored on board. The air is ejects at 6 km/sec and so has the same power level as the upper stage, but the acceleration is largely vertical, so, it requires 326.3 seconds to accelerate to 3.2 km/sec. It moves straight up 52 km before heading off at right angles toward its trajectory to the moon and travelling another 430 km downrange before switchin on the propellant flow. At that point is is 7 degrees above the horizon relative to the launch center. For this reason, several telescopes with 20 kW laser beams and adaptive optics beam energy to the spacecraft.

AEROSHELL

The wafer stack is surrounded by an aerogel filling forming an aeroshell to give the system lifting properties, while inducing air flow into the MEMS jets. Meanwhile the MEMS electrospray rockets cover the rim in a way that allows switching between elements to change direction of thrust relative to the wafer receiver and CG. So, the disk rises vertically over the launch laser and has the ability to change thrust vector relative to the receiver so that angle of attack can vary in ways that reduce drag, and maintain optimal flight path and energy reception.

MAX Q

40 seconds after launch, at 5.9 km altitude, thrust is reduced to maintain subsonic speeds until air density is reduced rising to an altitude of 52 km over the next three minutes. An appropriate level to maintain conditions. At a distance of 215 km from the launch point the device is 14 degrees above the horizon at both the launch center and 14 degrees above the horizon at a point 430 km away where a second 20 kW laser operates. By the time the vehicle is overhead of the downrange facility, it is 7 degrees above the horizon from the launch center, and begins climbing in altitude along a trajectory to the moon. Because of the shape of the Earth and its rotation, relative to this trajectory, the vehicle is 3 degrees above the horizon of the downrange laser when it achieves Trans Lunar Injection speed.

Terminal velocity is chosen so that the vehicle is 30 degrees above the horizon when lunar landing is to take place and rising. There is only a slight 4 degree variation between the two lasers, and having two lasers gives some backup.


AFTER LANDING

Upon settling down on the lunar surface, a 300 mm diameter wafer with the sun directly overhead, receives 97 watts of solar energy and at 80% efficiency, generates 77.4 watts from sunlight. Now, the ability to send a laser beam that energises the same wafer to 331 watts, with nearly 100% efficiency, provides an efficient start to the replication process! Within 15 minutes a ton of machine cells spreads from the landing point forming a dark spot some 16 meters in diameter.

UTILITY FOG

The laser beam now acts as a command and control system for the growing population of machine cells on the moon. Well before the sun sets at the landing point, the entire lunar surface has been processed to a depth of several meters, creating an array of lunar bases.

LUNAR MAGLEV & LUNAR LAUNCHERS

A 300 km lunar maglev that accelerates payloads at one gee has the ability to project objects from the lunar surface, or slow objects arriving at lunar escape velocity, if they are well aimed and guided. A network of maglev tracks also operate to transport objects anywhere on the lunar surface.

L4 and L5 SOLAR POWER STATIONS

Materials processed and then ejected from the lunar surface and use laser powered ion rockets powered from lunar surface, to stop at L4 and L5. This allows the assembly of massive power stations a L4 and L5 that are used to propel ships launched from the moon deeper into space.

GEO SOLAR POWER STATIONS

Materials processed and then ejected from the lunar surface and use laser powered ion rockets powered from L4 and L5, to enter GEO orbits around Earth. This allows the assembly of massive power stations at GEO, that are used to propel ships launched from Earth into orbit and beyond.

https://www.youtube.com/watch?v=8xy6YKTu51c

ASTEROIDS

Accelerating at 2 gees for a distance of 996 km attains a speed of 6.25 km/sec - which is sufficient to carry a well aimed payload from Earth Orbit to the asteroid belt in 38 weeks. Once there, similar processes take place there to process asteroids into useful products. Speeds are 1/6th the rate because sunlight is only 220 W/m2 instead of 1368 W/m2.

6.4 nanograms per machine cell,
56.8 microwatts per machine cell in sun,
1.7 million machine cells at the outset,
16.2 seconds replication time.

The moon intercepts 12.97x10^(15) Watts of solar energy. Generating 10 quadrillion watts when fully coated with machine cells. At 56.8 microwatts per cell, this requires at least 228.34x10^(18) cells. This takes 19 minutes to achieve starting with one cell. 13 minutes starting with 1.7 million cells.

Since a cell can be tossed half way around the moon in no less than 64 minutes, using electrostatic or electro magnetic means, if accelerated to 1.6 km/sec, it will take more than an hour to cover the sunlit side of the moon. Since it take 29 days for the sun to come back to the same position in the sky, it will take on the order of two weeks to cover the entire lunar surface with cells.

To avoid negative publicity, it is likely that such a system as described here and above, would land at Daedalus crater a 93 km diameter 3 km deep on the lunar far side, at a third quarter moon, and by the time the moon is a waning crescent, that back side is filled from Mare Marginus to Mare Orientale, all beyond the view of Earthlings, reducing reflectivity dramatically.

https://upload.wikimedia.org/wikiped...on-craters.jpg

Though one design feature could be to reflect say 20% of the light - of the local pre-cell terrain - to replicate the moon - only dimmer! Perceived only 50% dimmer by people looking at the moon!

http://www.lutron.com/TechnicalDocum..._Perceived.pdf

One interesting feature of a moon covered with self replicating machine cells, would be the ablity to draw images across the surface of the moon by equipping a certain number of them with variable reflectivity. This permits them to reflect 8x as much light as the moon currently reflects, and appear 3x as bright as the moon now does or 5x as bright as the moon would appear after being covered with solar collectors.

So, you could advertise your logo or other information on the moon. This is something written about in Robert Helinlein's story "The Man Who Sold the Moon".

https://openlibrary.org/books/OL1557..._sold_the_moon

Its also something people are thinking about today

http://www.theverge.com/2014/5/15/57...o-moon-in-2015

10 quadrillion watts of power converts 250,000 tons of rock into 69,250 tons of cells every second. Now the moon is 3340 kg/m3 on average, but the crust averages 2550 kg/m3 with the core up to 5000 kg/m3.

This means at the outset, a total of 98,039 cubic meters of rock is converted to cells every second. Spread across the surface of the moon, this translates to 1.56 mm per week. 81 mm per year. 810 mm per decade.

In terms of present human population, this is 296 tons of cells per year for every man woman and child on Earth. More than four tons of material processed per day per person.

With a laser infrastructure, we could use lasers to lift people off Earth in large numbers;

https://www.youtube.com/watch?v=8xy6YKTu51c

and transport them across the Earth / Moon distance at one gee, taking only 3 hours to transit.

https://www.youtube.com/watch?v=QICCrlmBjvY
https://www.youtube.com/watch?v=Z-KZXCyBf8o

The moon base consists of a large centrifuge with the sides canted out slightly.

http://www.funfairevents.co.za/image...s/Tornado2.jpg

Much larger than the rides you find at the circus.

A 2.5 km diameter and 0.5 km tall cylinder that is 2.667 km diameter at the top and 2.500 km diameter at the bottom, and rotates 114 m/sec speed completing a round every 2.3 minutes, produces 98.6% gee radially that when added to 1/6th gee downward, produces 1.000 gee directly through the surface canted at an average of 9.6 degrees. The cylinder is held in tracks and suppored magnetically and sports a 20 meter (66 foot) tall roof. At the base of the cylinder 392.7 hectare one gee surface is a stack of 150 moving sidewalks that slow from 114 m/sec to 1 m/sec as the angle relative to the center of rotation changes from 90 degrees to 0 degrees as gravity is reduced from 1 gee to 1/6th gee. Each cylinder contains 62,832 people at the same living standard as Monaco. 117,456 cylinders at the center of a hexagon with 11.1 km length edges, totalling 320 sq km, separated by a distance of 22.2 km.

Each person has access to 5.5 MW of power, and 1 ton of raw material per day. The entire array of centrifuge neighborhoods is produced in 10 days.

It takes about a month to take a few tons of plant and animal cells from Earth and produce sufficient cells to feed 7.38 billion people with adequate diets. This process uses cell cultures fed by organic chemicals that are then shaped into food items using 3D food printers.

https://www.youtube.com/watch?v=eEez9lNh8Uw

http://www.dailymail.co.uk/sciencete...gredients.html

So, once the moon has been transformed in this way, similar payloads are sent to the major asteroids to process these over the next few years;

Name Diam (km) Dimen (km) Dist (AU) Discovered Discoverer Class

1 Ceres 946 965×962×891 2.766 January 1, 1801 Piazzi, G. G
4 Vesta 525.4 572×557×446 2.362 March 29, 1807 Olbers, H. W. V
2 Pallas 512 550×516×476 2.773 March 28, 1802 Olbers, H. W. B
10 Hygiea 431 530×407×370 3.139 April 12, 1849 de Gasparis, A. C
704 Interamnia 326 350×304 3.062 October 2, 1910 Cerulli, V. F
52 Europa 315 380×330×250 3.095 February 4, 1858 Goldschmidt, H. C
511 Davida 289 357×294×231 3.168 May 30, 1903 Dugan, R. S. C
87 Sylvia 286 385×265×230 3.485 May 16, 1866 Pogson, N. R. X
65 Cybele 273 302×290×232 3.439 March 8, 1861 Tempel, E. W. C
15 Eunomia 268 357×255×212 2.643 July 29, 1851 de Gasparis, A. S
3 Juno 258 320×267×200 2.672 September 1, 1804 Harding, K. L. S

Name Mass (×10^18 kg) Precision Approx. prop'n all asteroids
1 Ceres........... 939.3 0.05% (939-940).................. 31%
4 Vesta........... 259.076 0.0004% (259.075-259.077) 8.6%
2 Pallas........... 201 6.4% (188-214)..................... 6.7%
10 Hygiea....... 86.7 1.7% (85.2-88.4)................... 2.9%
31 Euphrosyne 58.1 34% (38.4-77.8).................... 1.9%
704 Interamnia 38.8 4.6% (37.0-40.6)................... 1.3%
511 Davida...... 37.7 5.2% (35.7-39.7)................... 1.3%
532 Herculina. 33 17% (27-39).......................... 1.1%
15 Eunomia..... 31.8 0.9% (31.5-32.1).................... 1.1%
3 Juno............ 28.6 16% (24.0-33.2).................... 0.95%

http://www.orionsarm.com/im_store/bishop.jpg
http://www.iase.cc/openair.htm

A total of 1,704.1 x 10^15 tons is available at 10 locations. At 35% material utilitsation, and 10 tons per square meter, 59.6 billion square kilometers may be built, in the form of Bishop Rings. With a 2,000 km diameter ring that's 68.5 km wide, each ring has a surface area of 137,000 sq km and a mass of 1.37 trillion tons. This is 435,354 Bishop Rings each 2000 km in diameter each separated by a distance of 5,685 km when evenly spaced around the asteroid belt.

Each Bishop Ring starts with a human population of 16,952 people from Earth's moon. Each person is allocated 8 sq km. Another 0.08 km allocated as common area for each colony. This is a central city for each ring, totalling 1356.08 sq km. At the outset 8 hectares are allocated here per person (in the central city) which is 1% of the area allocated to each person in the rest of the Bishop Ring.

So, extracting people from Earth to join the off-world colonies;

https://www.youtube.com/watch?v=sZNzz4SaTYk

using resources extracted from the moon, and later expanded to the asteroids and to Mars, we have

Lunar Centrifuge at this population density (16,000 / km2)
https://www.youtube.com/watch?v=aDgkKYMZrN4

Bishop Ring 'starter'city at this population density (64 hectares/home)
https://www.youtube.com/watch?v=IWpjqtzFmaY

Family of Four 64 sq km Estate population density
https://www.youtube.com/watch?v=1cSB0_tgnN4

Meanwhile, the few who remain on Earth oversee the use of this technology to rid the Earth of the excesses of 20th century industry and over-population, while building one billion time shares serviced by advanced automation for each of 8 persons to visit up to one month per year on average.

https://www.youtube.com/watch?v=ZOlgC79Fqf8

This could be achieved in less than five years, once certain details are worked out fully. Yet, this won't be enough, as Carl Sagan pointed out 40 years ago which gives us the tools and skills to expand outward to the stars.

https://www.youtube.com/watch?v=WjzzGawND3s
https://www.youtube.com/watch?v=Q6goNzXrmFs