2014 FE72 has an aphelion distance of 4,275 AU +/- 20%. Since the orbit period is on the order of 280,000 years, and we have observed it for two, we will have to watch it a little longer to pin down the orbit exactly. Perihelion, at 36 AU, was in 1965, so it is still close to the perihelion distance. That's why we were able to find it. It is ~170 km in diameter, depending how light or dark the surface is.
I guess I'm imaginary, because I retired at 47. The trick is not spending all the money you earn. Most people seem to spend on unnecessary luxuries. It may make them feel better *now*, but they will pay for it later by having to work more.
It was only once that they ran out of hydraulic fluid, they fixed that the next flight. Sticky engine gimbal caused another crash. The engine pivots to help steer it for landing, but it was moving too slowly, so they landed at an angle instead of vertical. Finally, one time a landing leg failed to lock. So it landed vertical, but then fell over. They have been learning by crashing, and generally don't have the same problem twice. Since expendable rockets *always* crash, flight testing the landing system this way doesn't cost much extra.
Space industry amounted to $335 billion last year. Most of that is commercial satellites, which are quite profitable. Do you think AT&T bought DirecTV so they could lose money?
> Isn't your home a lava gas home made with mirrors?
My house is brick on the outside, and making brick involves heating it to where it starts to melt. Historically that's been done with a furnace, but there is no fundamental reason it can't be done with concentrated sunlight.
As a practical matter, the Sun doesn't always shine on Earth, but it does in space. The heating cycle for bricks takes longer than a day, so using sunlight is complicated.
This sounds like the Space Station Phase B (preliminary design) contracts we worked on back in 1986-1987. We built some prototype modules back then too. Then it took a decade, from '88 to '98, to get to first hardware launch. Based on that history, look for first Deep Space Habitat launch in 2028.
> When in reality, the best experience is an ad-free experience.
That's not always true. I do hardware design, and enjoy woodworking, and read paper magazines related to both. I find the ads in those magazines useful, because they are very relevant. Now, if I found a penis enhancer ad in either magazine, that would be bad.
If Facebook or any other site offered a checklist of ad topics to serve me, I would find that reasonable. I could pick the ones I was interested in, and not see the rest.
> Then there's no one left to care enough to prevent the US private industry from delivering heavy lift vehicles that will actually get used.
Space industry in total was $335 billion in 2015 ( http://www.sia.org/wp-content/... ), two-thirds of which are satellite-based. There were 1,381 active satellites by the end of last year. NASA just isn't driving space development any more. They account for a little over 5% of the total. A rocket like the Falcon 9/Heavy is a good combination to address the whole market. Falcon 9 for the majority of launches, and Falcon Heavy for the occasional ones that need bigger payload mass. Since the Heavy uses the same production line, it doesn't get penalized much for a lower flight rate.
Space systems engineer here. Overall these are good ideas, but I think the mission sequence and technical details are slightly off:
* Near Earth Asteroids (NEA) are easier to start with. They can be reached entirely with electric propulsion, while landing on the Moon requires chemical propulsion. The latter require about 10 times as much propellant for the same mission velocity. To reach an asteroid you can use the Moon itself for a gravity assist, so the delta-V to reach the well-placed ones is actually lower than reaching the Lunar surface.
* The mass return ratio of an electric tug fetching rock from NEAs is about 200:1 over it's operating life, assuming you mine some of the returned rock for propellant for later trips. Up to 20% of the rock is water and carbon compounds. These can be reformed to oxygen + hydrocarbons, which is high thrust chemical fuel. This fuel can then be used to land on the Moon, or other missions that need the higher thrust levels. 20% x 200:1 means the yield of chemical fuel can be 40:1.
* Processing rock to useful products is best done in open space where you get sunlight 100% of the time. The Lunar surface only averages 50%, and polar craters where ice freezes out get 0%, which is why they are cold enough to trap ice.
* Five out of six discovered NEA are larger than 30 meters in size ( http://neo.jpl.nasa.gov/stats/ ), which means their mass is a minimum of 18,000 tons, and ranges much higher depending on composition and size. These are too massive to move, so mining will be a surface-scraping operation at first. Dust and pebbles will be easier to run through the processing equipment. Hollowing out natural asteroids is not a good idea, because most of them are the end result of multiple impacts. They are very likely structurally flawed. Placing smaller pieces in storage lockers *around* fabricated modules can provide radiation shielding and hold pressure more safely.
* Once you have access to the Lunar surface, set up a centrifugal catapult and launch bulk materials into orbit for processing. You want to use both Lunar and NEA raw materials because they have different histories and compositions. Lunar launch, even with 50% sunlight, has much higher mass return ratios and shorter transit times, so you definitely want it as an upgrade.
* Definitely bootstrap mining and processing wherever you go. There are just as many asteroids near a Mars Cycler orbit as near Earth, our home planet is not special in that regard. So a tug can fetch raw rock to your cycling habitat for radiation shielding and later processing. Phobos is a very large resource to mine, and it is likely to have water and carbon compounds (we need to actually visit it to be sure.
* Again, the general idea of bootstrapping mining and production from local materials is very much right. The leverage on not having to bring everything from Earth is huge.
The summary mentions Bezos is a Trekkie. He wants his own space program. Those are not cheap. Pretty much all the people doing that (Musk, Allen, Bezos, Branson, Bigelow, Henri of Luxembourg, and the investors in Planetary Resources) are billionaires.
> Now the long slide since 2008 will continue until some disruptive element creates economic opportunity.
Personal automation in the form of machines that can make more machines, which in turn make the stuff you need. Jobs and income will go down, because stuff you make for yourself isn't counted as work or income. Despite that, production will go up and people will be better off.
For example, automated machine shop and foundry makes robot farm tractors, among other things. The tractors in turn grow food for the owners. Since the machine shop is too expensive for the average person, they would be run as cooperatives, like my power company and credit union are. When you make your own stuff using your own equipment, you get to skip all the middle-man markups and profit, and you don't pay income or sales taxes on it. You are also immune to layoffs, because you own the equipment. You don't have to work very hard for it, either, because the equipment is mostly automated. A regular farm tractor can produce food for 50 or 100 people, an automated one can do at least as well. You still need a farmer to oversee the tractors and decide when to plant and harvest, but for most people the food just shows up on a regular basis.
Actually, Day One for Bitcoin was buying two pizzas for 10,000 BTC, and that was 18 months after the network first booted up. Until then it was just a cryptographic curiosity. The Silk Road prosecution revealed that only 4% of bitcoin transactions were used on their black market to buy drugs and other nefarious purposes. That's not much higher than the ratio of illicit drugs to GDP worldwide (3%), and is far less than the total underground economy in the US (20%). The underground economy = black market (illegal) + off the books economy (nominally legal but not reported).
Good old cash is still by far the preferred choice for illegal activity. That's why over 70% of hundred Dollar bills are overseas:
> All transactions are recorded in the block chain and supposedly available for inspection by anyone.
Yes, they are. But they only record the sending address, receiving address, and the amount being sent. No names or other personal information. Here, look at a transaction from the most recent block, and tell me anything about the people involved:
> (you could "make" more money by stuffing it under a mattress, than by using it to do something economically productive).
That's only true if the rate of deflation was greater than the nominal rate of return on other investments. Stock earnings, as measured by the S&P 500 have grown at an average of 6.6% over the last 55 years, plus paid out a few percent in cash dividends on top of that. If the dividends were re-invested, then total earnings would grow around 8.8%. If your money were deflating at 2% you would be far better off with stocks.
> Bitcoin has always been expressly designed to favor the people who got bitcoins early.
And start-ups favor the founders and early investors, so what's your point?
For the first 18 months bitcoins were worth *zero*, they were merely an interesting experiment. There was no guarantee they would ever be worth anything in real terms. Then someone bought two pizzas for 10,000 BTC, establishing a value of 0.4 cents/BTC, meaning the mining reward at the time was 20 cents. Given that there were perhaps 100 people mining at the time, the average reward was 1.2 cents an hour, hardly a get rich quick scheme.
> and usually costs more energy than that thing could harvest in space).
That's incorrect. The Falcon 9 rocket has a liftoff mass of 550,000. Their website says it is 96% rocket, and 4% payload. So 24 units of rocket per unit of payload. The combustion energy of the fuel is 13 MJ/kg, and the embodied energy of the rocket hardware is in the same range. So about 312 MJ/kg is required to get the payload into orbit. 1 kg of modern space solar panels produce 175 Watts, and they last >15 years in low orbit. Duty cycle is 60% in low orbit due to the Earth's shadow. So they produce 31,556,925 seconds/year x 15 years x 60% x 175 Watts/kg = 49.7 GJ/kg. That's 160 times their launch energy. That's why satellites almost universally use solar panels instead of fuel cells or some other power source.
That's not required. A partially-built space elevator can bootstrap it's own construction and lower launch costs as it grows. By the way, "tether" is just the cable between the ends. It is no more a complete space elevator than the cable of a suspension bridge are the whole bridge.
How do you start bootstrapping the space elevator? With cheaper rockets. What does Jeff Bezos own? A rocket company working on cheaper rockets (and Amazon.com, which pays for the rocket stuff)
> Thought experiment: you use nice pretty reflectors to smelt aluminium. You now have a ball (or, more likely, an expanding cloud) of +/- 700C molten metal.
Actually, extracting Aluminum is more complicated than just heating, since most of that metal everywhere (Earth and space) is in the form of oxide minerals. However Iron in the form of metallic asteroids *is* available already reduced to metal, so I will substitute that in my discussion. You build a rotating circular crucible and throw chunks of metallic asteroid into it. Focus enough sunlight on it to melt the batch. Bits of rocky inclusions will float to the "top" (center) because they are less dense, and the molten iron will sink to the "bottom" (rim). Throw in a bit of carbon from the C-type asteroids, since Iron + Carbon = steel. The bottom of your crucible has a hole that you tap to extrude the molten metal, which then passes through cooled rollers to provide a final shape. On Earth this is called "continuous casting". The rollers can form an "H" shape for structural beams, flat sheet, or whatever else you need, by just choosing roller positions. Cooling water goes through the rollers, and out to radiator pipes. They don't have to cool to room temperature, just enough to keep the rollers from deforming. Since the radiators will be rejecting heat at a pretty high temperature, they don't have to be very large.
> I'm not saying we should shitcan the whole idea, but the "Futurist" camp really has to stop talking about how trivial things are once we get most of the way out of the gravity well,
Actual space systems engineers like myself don't trivialize the tasks. Most space enthusiasts don't even know what materials are available to work with, or what the solar flux is, or the realities of working in the space environment. But some of us do know all that stuff, collectively. I don't know everything, either, and I work in the field. Generally you need teams of specialists in different subjects to complete a project. So you won't get a complete answer in a forum comment. You get it in a study report that lots of people contributed to.
Bezos runs a rocket company (besides Amazon.com). I'm sure he has people who can tell him to 3 significant figures how much energy is needed. I can too, 31.273 MJ/kg. I do space systems engineering, and it's one of the basic facts you learn. At wholesale electric rates, that comes to $0.43/kg, about what I pay for a bag of potatoes. The fact that current launch prices are at least 3,800 times higher just means *we're doing it wrong* and are terribly inefficient at it.
> the tons of raw metals and other materials that you would need for industrial operations.
Those tons are already in space, on the Moon and nearby asteroids. There is plenty of solar energy in orbit to process those materials. And you can bootstrap industry via the Seed Factory concept (http://en.wikibooks.org/wiki/Seed_Factories). That's where you send a starter set of machines, and use them to make *more* machines out of local materials already in space. Once your production capacity is big enough, you start making products for sale.
Governments are irrelevant. Space industry worldwide is $324 billion/yr, and NASA represents 5.5% of that. Most of the 1250 active satellites in orbit are commercial.
And efficient transport to and from orbit is quite possible, but not the simplistic space elevator concept that is usually described in the media. That's based on Tsiolkovsky's original 1895 *thought experiment*, which isn't anything like a proper engineering design. The fact is the Earth's gravity well is too deep to span with a single cable from bottom to top.
One end point design breaks up the elevator into three sections of cable. The one in the middle hangs vertically in the Earth's gravity. The upper and lower ends rotate so as to provide sub-orbital capture at the bottom end, and transfer to higher orbits at the upper end. Because it resembles a bicycle (two rotating objects connected by a non-rotating structure), the "Bicyclevator" is a name you can use. A sub-orbital launch system meets up with the bottom section, transfers payload, then lets go and does a sub-orbital re-entry. This is much easier than conventional rockets that go all the way to orbit.
Such a transport system is an *end point* of evolution, like Atlanta's airport is the end point of 85 years of growth. Atlanta-Hartsfield didn't start out handling 100 million passengers a year. You build a small section of space elevator to start with, and use that to bootstrap the rest of the construction as increased traffic justifies it. Since each increment of construction pays its own way, you don't need government finance.
> The moon should be used for energy-heavy industries, though, not space.
Actually, open space is a better location. It gets sunlight 100% of the time, instead of 50% on the surface. Modern space solar panels produce ~175 W/kg, and the energy to reach Lunar orbit from the surface is 1.53 MJ. Dividing, we get 8,743 seconds for the panel to produce enough energy to lift it's own mass from the Moon to orbit. That's a bit under 2.5 hours. Over a working life of ~15 years, the panel will produce >50,000 times the energy to lift itself to orbit, but only half as much on the surface.
Typical embodied energy in products is 10 MJ/kg, or 6.5 times the launch energy. So on the surface, the panel can process 4000 times it's mass to products, while in orbit it can process 8000, which is a better answer.
> The closest source of raw materials in space is the moon, and that is not exactly an economical place to get anything from.
Actually, it is. Modern triple-layer space solar panels produce ~175W/kg. It takes 1.53 MJ/kg to reach a reasonable Lunar orbit. Therefore the solar panel can produce the energy to put its own mass in orbit in 8,750 seconds, or 2.4 hours. Allow for 50% night and 50% operating efficiency, and we get 10 hours. So a solar panel can put 875 times its mass in orbit in a year, and panels last ~15 years beyond LEO, so 13,000 times its mass.
How do you get stuff in orbit? The Moon is a small body with no atmosphere, so an electric centrifuge can throw loads of raw rock directly into orbit. Materials like carbon fiber are perfectly adequate for the centrifuge arm, and electric motors are not rocket science:-). You need either a small kick motor or a collection system in orbit to circularize the orbit, otherwise it comes back down to ground level one orbit later.
Slashdot Mirror
2014 FE72 has an aphelion distance of 4,275 AU +/- 20%. Since the orbit period is on the order of 280,000 years, and we have observed it for two, we will have to watch it a little longer to pin down the orbit exactly. Perihelion, at 36 AU, was in 1965, so it is still close to the perihelion distance. That's why we were able to find it. It is ~170 km in diameter, depending how light or dark the surface is.
Source: http://www.minorplanetcenter.n...
I guess I'm imaginary, because I retired at 47. The trick is not spending all the money you earn. Most people seem to spend on unnecessary luxuries. It may make them feel better *now*, but they will pay for it later by having to work more.
A lot of their material has been online for years:
http://naca.larc.nasa.gov/sear...
It was only once that they ran out of hydraulic fluid, they fixed that the next flight. Sticky engine gimbal caused another crash. The engine pivots to help steer it for landing, but it was moving too slowly, so they landed at an angle instead of vertical. Finally, one time a landing leg failed to lock. So it landed vertical, but then fell over. They have been learning by crashing, and generally don't have the same problem twice. Since expendable rockets *always* crash, flight testing the landing system this way doesn't cost much extra.
Space industry amounted to $335 billion last year. Most of that is commercial satellites, which are quite profitable. Do you think AT&T bought DirecTV so they could lose money?
No, their approach is to gain immunity by buying the content creators. Thus Universal Pictures is owned by Comcast.
> Isn't your home a lava gas home made with mirrors?
My house is brick on the outside, and making brick involves heating it to where it starts to melt. Historically that's been done with a furnace, but there is no fundamental reason it can't be done with concentrated sunlight.
As a practical matter, the Sun doesn't always shine on Earth, but it does in space. The heating cycle for bricks takes longer than a day, so using sunlight is complicated.
This sounds like the Space Station Phase B (preliminary design) contracts we worked on back in 1986-1987. We built some prototype modules back then too. Then it took a decade, from '88 to '98, to get to first hardware launch. Based on that history, look for first Deep Space Habitat launch in 2028.
> When in reality, the best experience is an ad-free experience.
That's not always true. I do hardware design, and enjoy woodworking, and read paper magazines related to both. I find the ads in those magazines useful, because they are very relevant. Now, if I found a penis enhancer ad in either magazine, that would be bad.
If Facebook or any other site offered a checklist of ad topics to serve me, I would find that reasonable. I could pick the ones I was interested in, and not see the rest.
> Then there's no one left to care enough to prevent the US private industry from delivering heavy lift vehicles that will actually get used.
Space industry in total was $335 billion in 2015 ( http://www.sia.org/wp-content/... ), two-thirds of which are satellite-based. There were 1,381 active satellites by the end of last year. NASA just isn't driving space development any more. They account for a little over 5% of the total. A rocket like the Falcon 9/Heavy is a good combination to address the whole market. Falcon 9 for the majority of launches, and Falcon Heavy for the occasional ones that need bigger payload mass. Since the Heavy uses the same production line, it doesn't get penalized much for a lower flight rate.
Space systems engineer here. Overall these are good ideas, but I think the mission sequence and technical details are slightly off:
* Near Earth Asteroids (NEA) are easier to start with. They can be reached entirely with electric propulsion, while landing on the Moon requires chemical propulsion. The latter require about 10 times as much propellant for the same mission velocity. To reach an asteroid you can use the Moon itself for a gravity assist, so the delta-V to reach the well-placed ones is actually lower than reaching the Lunar surface.
* The mass return ratio of an electric tug fetching rock from NEAs is about 200:1 over it's operating life, assuming you mine some of the returned rock for propellant for later trips. Up to 20% of the rock is water and carbon compounds. These can be reformed to oxygen + hydrocarbons, which is high thrust chemical fuel. This fuel can then be used to land on the Moon, or other missions that need the higher thrust levels. 20% x 200:1 means the yield of chemical fuel can be 40:1.
* Processing rock to useful products is best done in open space where you get sunlight 100% of the time. The Lunar surface only averages 50%, and polar craters where ice freezes out get 0%, which is why they are cold enough to trap ice.
* Five out of six discovered NEA are larger than 30 meters in size ( http://neo.jpl.nasa.gov/stats/ ), which means their mass is a minimum of 18,000 tons, and ranges much higher depending on composition and size. These are too massive to move, so mining will be a surface-scraping operation at first. Dust and pebbles will be easier to run through the processing equipment. Hollowing out natural asteroids is not a good idea, because most of them are the end result of multiple impacts. They are very likely structurally flawed. Placing smaller pieces in storage lockers *around* fabricated modules can provide radiation shielding and hold pressure more safely.
* Once you have access to the Lunar surface, set up a centrifugal catapult and launch bulk materials into orbit for processing. You want to use both Lunar and NEA raw materials because they have different histories and compositions. Lunar launch, even with 50% sunlight, has much higher mass return ratios and shorter transit times, so you definitely want it as an upgrade.
* Definitely bootstrap mining and processing wherever you go. There are just as many asteroids near a Mars Cycler orbit as near Earth, our home planet is not special in that regard. So a tug can fetch raw rock to your cycling habitat for radiation shielding and later processing. Phobos is a very large resource to mine, and it is likely to have water and carbon compounds (we need to actually visit it to be sure.
* Again, the general idea of bootstrapping mining and production from local materials is very much right. The leverage on not having to bring everything from Earth is huge.
The summary mentions Bezos is a Trekkie. He wants his own space program. Those are not cheap. Pretty much all the people doing that (Musk, Allen, Bezos, Branson, Bigelow, Henri of Luxembourg, and the investors in Planetary Resources) are billionaires.
> Now the long slide since 2008 will continue until some disruptive element creates economic opportunity.
Personal automation in the form of machines that can make more machines, which in turn make the stuff you need. Jobs and income will go down, because stuff you make for yourself isn't counted as work or income. Despite that, production will go up and people will be better off.
For example, automated machine shop and foundry makes robot farm tractors, among other things. The tractors in turn grow food for the owners. Since the machine shop is too expensive for the average person, they would be run as cooperatives, like my power company and credit union are. When you make your own stuff using your own equipment, you get to skip all the middle-man markups and profit, and you don't pay income or sales taxes on it. You are also immune to layoffs, because you own the equipment. You don't have to work very hard for it, either, because the equipment is mostly automated. A regular farm tractor can produce food for 50 or 100 people, an automated one can do at least as well. You still need a farmer to oversee the tractors and decide when to plant and harvest, but for most people the food just shows up on a regular basis.
Actually, Day One for Bitcoin was buying two pizzas for 10,000 BTC, and that was 18 months after the network first booted up. Until then it was just a cryptographic curiosity. The Silk Road prosecution revealed that only 4% of bitcoin transactions were used on their black market to buy drugs and other nefarious purposes. That's not much higher than the ratio of illicit drugs to GDP worldwide (3%), and is far less than the total underground economy in the US (20%). The underground economy = black market (illegal) + off the books economy (nominally legal but not reported).
Good old cash is still by far the preferred choice for illegal activity. That's why over 70% of hundred Dollar bills are overseas:
http://www.npr.org/sections/mo...
> All transactions are recorded in the block chain and supposedly available for inspection by anyone.
Yes, they are. But they only record the sending address, receiving address, and the amount being sent. No names or other personal information. Here, look at a transaction from the most recent block, and tell me anything about the people involved:
https://blockchain.info/tx/ce1...
> (you could "make" more money by stuffing it under a mattress, than by using it to do something economically productive).
That's only true if the rate of deflation was greater than the nominal rate of return on other investments. Stock earnings, as measured by the S&P 500 have grown at an average of 6.6% over the last 55 years, plus paid out a few percent in cash dividends on top of that. If the dividends were re-invested, then total earnings would grow around 8.8%. If your money were deflating at 2% you would be far better off with stocks.
> Bitcoin has always been expressly designed to favor the people who got bitcoins early.
And start-ups favor the founders and early investors, so what's your point?
For the first 18 months bitcoins were worth *zero*, they were merely an interesting experiment. There was no guarantee they would ever be worth anything in real terms. Then someone bought two pizzas for 10,000 BTC, establishing a value of 0.4 cents/BTC, meaning the mining reward at the time was 20 cents. Given that there were perhaps 100 people mining at the time, the average reward was 1.2 cents an hour, hardly a get rich quick scheme.
Bezos has a Bachelors in Electrical Engineering and one in Computer Science, from Princeton University. He's not exactly a dummy.
> and usually costs more energy than that thing could harvest in space).
That's incorrect. The Falcon 9 rocket has a liftoff mass of 550,000. Their website says it is 96% rocket, and 4% payload. So 24 units of rocket per unit of payload. The combustion energy of the fuel is 13 MJ/kg, and the embodied energy of the rocket hardware is in the same range. So about 312 MJ/kg is required to get the payload into orbit. 1 kg of modern space solar panels produce 175 Watts, and they last >15 years in low orbit. Duty cycle is 60% in low orbit due to the Earth's shadow. So they produce 31,556,925 seconds/year x 15 years x 60% x 175 Watts/kg = 49.7 GJ/kg. That's 160 times their launch energy. That's why satellites almost universally use solar panels instead of fuel cells or some other power source.
> After we have a fully working space tether,
That's not required. A partially-built space elevator can bootstrap it's own construction and lower launch costs as it grows. By the way, "tether" is just the cable between the ends. It is no more a complete space elevator than the cable of a suspension bridge are the whole bridge.
How do you start bootstrapping the space elevator? With cheaper rockets. What does Jeff Bezos own? A rocket company working on cheaper rockets (and Amazon.com, which pays for the rocket stuff)
> Thought experiment: you use nice pretty reflectors to smelt aluminium. You now have a ball (or, more likely, an expanding cloud) of +/- 700C molten metal.
Actually, extracting Aluminum is more complicated than just heating, since most of that metal everywhere (Earth and space) is in the form of oxide minerals. However Iron in the form of metallic asteroids *is* available already reduced to metal, so I will substitute that in my discussion. You build a rotating circular crucible and throw chunks of metallic asteroid into it. Focus enough sunlight on it to melt the batch. Bits of rocky inclusions will float to the "top" (center) because they are less dense, and the molten iron will sink to the "bottom" (rim). Throw in a bit of carbon from the C-type asteroids, since Iron + Carbon = steel. The bottom of your crucible has a hole that you tap to extrude the molten metal, which then passes through cooled rollers to provide a final shape. On Earth this is called "continuous casting". The rollers can form an "H" shape for structural beams, flat sheet, or whatever else you need, by just choosing roller positions. Cooling water goes through the rollers, and out to radiator pipes. They don't have to cool to room temperature, just enough to keep the rollers from deforming. Since the radiators will be rejecting heat at a pretty high temperature, they don't have to be very large.
> I'm not saying we should shitcan the whole idea, but the "Futurist" camp really has to stop talking about how trivial things are once we get most of the way out of the gravity well,
Actual space systems engineers like myself don't trivialize the tasks. Most space enthusiasts don't even know what materials are available to work with, or what the solar flux is, or the realities of working in the space environment. But some of us do know all that stuff, collectively. I don't know everything, either, and I work in the field. Generally you need teams of specialists in different subjects to complete a project. So you won't get a complete answer in a forum comment. You get it in a study report that lots of people contributed to.
Bezos runs a rocket company (besides Amazon.com). I'm sure he has people who can tell him to 3 significant figures how much energy is needed. I can too, 31.273 MJ/kg. I do space systems engineering, and it's one of the basic facts you learn. At wholesale electric rates, that comes to $0.43/kg, about what I pay for a bag of potatoes. The fact that current launch prices are at least 3,800 times higher just means *we're doing it wrong* and are terribly inefficient at it.
> the tons of raw metals and other materials that you would need for industrial operations.
Those tons are already in space, on the Moon and nearby asteroids. There is plenty of solar energy in orbit to process those materials. And you can bootstrap industry via the Seed Factory concept (http://en.wikibooks.org/wiki/Seed_Factories). That's where you send a starter set of machines, and use them to make *more* machines out of local materials already in space. Once your production capacity is big enough, you start making products for sale.
Governments are irrelevant. Space industry worldwide is $324 billion/yr, and NASA represents 5.5% of that. Most of the 1250 active satellites in orbit are commercial.
And efficient transport to and from orbit is quite possible, but not the simplistic space elevator concept that is usually described in the media. That's based on Tsiolkovsky's original 1895 *thought experiment*, which isn't anything like a proper engineering design. The fact is the Earth's gravity well is too deep to span with a single cable from bottom to top.
One end point design breaks up the elevator into three sections of cable. The one in the middle hangs vertically in the Earth's gravity. The upper and lower ends rotate so as to provide sub-orbital capture at the bottom end, and transfer to higher orbits at the upper end. Because it resembles a bicycle (two rotating objects connected by a non-rotating structure), the "Bicyclevator" is a name you can use. A sub-orbital launch system meets up with the bottom section, transfers payload, then lets go and does a sub-orbital re-entry. This is much easier than conventional rockets that go all the way to orbit.
Such a transport system is an *end point* of evolution, like Atlanta's airport is the end point of 85 years of growth. Atlanta-Hartsfield didn't start out handling 100 million passengers a year. You build a small section of space elevator to start with, and use that to bootstrap the rest of the construction as increased traffic justifies it. Since each increment of construction pays its own way, you don't need government finance.
> The moon should be used for energy-heavy industries, though, not space.
Actually, open space is a better location. It gets sunlight 100% of the time, instead of 50% on the surface. Modern space solar panels produce ~175 W/kg, and the energy to reach Lunar orbit from the surface is 1.53 MJ. Dividing, we get 8,743 seconds for the panel to produce enough energy to lift it's own mass from the Moon to orbit. That's a bit under 2.5 hours. Over a working life of ~15 years, the panel will produce >50,000 times the energy to lift itself to orbit, but only half as much on the surface.
Typical embodied energy in products is 10 MJ/kg, or 6.5 times the launch energy. So on the surface, the panel can process 4000 times it's mass to products, while in orbit it can process 8000, which is a better answer.
> The closest source of raw materials in space is the moon, and that is not exactly an economical place to get anything from.
Actually, it is. Modern triple-layer space solar panels produce ~175W/kg. It takes 1.53 MJ/kg to reach a reasonable Lunar orbit. Therefore the solar panel can produce the energy to put its own mass in orbit in 8,750 seconds, or 2.4 hours. Allow for 50% night and 50% operating efficiency, and we get 10 hours. So a solar panel can put 875 times its mass in orbit in a year, and panels last ~15 years beyond LEO, so 13,000 times its mass.
How do you get stuff in orbit? The Moon is a small body with no atmosphere, so an electric centrifuge can throw loads of raw rock directly into orbit. Materials like carbon fiber are perfectly adequate for the centrifuge arm, and electric motors are not rocket science :-). You need either a small kick motor or a collection system in orbit to circularize the orbit, otherwise it comes back down to ground level one orbit later.