A 10 ton asteroid tug with 20-25 tons of fuel can return about 1000 tons of asteroid rock to a high orbit, such as near the Moon. That's enough to shield a few Deep Space Habitat modules. Assume the modules are Space Station-sized, about 5x10 m cylinders. You want 1 meter of shielding, which is then a cylinder 7x10 meters, or 188 cubic meters. Chondrite type meteorites have a solid density of 2-3 tons/cubic meter, so the mass would be 375 to 560 tons. So you can cover roughly 2-3 modules. You build a cylinder of storage lockers around the pressure shell of the module, stuff each locker with rocks, and you are done.
The tug takes about 2 years to make the trip to a good Near Earth Asteroid, though the trip time will depend on which asteroid and when you leave. Because you want to use it as shielding, you grab dust and small rocks off the asteroid surface, and not big chunks. Later you can process the rock to extract water and other useful stuff. Since the tug's engines and solar arrays have a life of ~15 years, you can make multiple trips. The first one is for shielding, the ones after that are for processing.
10 tons of vehicle hardware should cost about two large comsats, or ~$600 million. It's mostly solar arrays and electric propulsion units, with enough multiples of each that a failure or two doesn't doom the mission. Each time the tug returns, you can fix whatever breaks before the next trip. The first load of propellant has to come from Earth, but the later trips can use water extracted from your asteroid rock.
> I do wonder how feasible it would be to build some sort of a hydraulically stabilized landing platform on top of the barge
Look up "Sea Launch", which was a partnership between Boeing, Kvaerner A.G. (Norwegian ship and drilling platform builder), and Russian rocket companies. They launched rockets from a converted drilling platform out in the Pacific Ocean.
A semi-submersible platform like that takes on ballast water to lower the center of mass below the waves, while the platform on top is held *above* the water on columns. The waves can then pass through the columns without moving the platform much, because it's not a solid wall like the side of a ship. The ballast water mass also makes the whole platform more massive and hard to move.
Right now (or very soon) you will likely be able to pick up drilling platforms for scrap value. With the price of oil so low, expensive ways to extract oil, like fracking and ocean drilling, can't make a profit, so the drilling companies stop doing it, and some of them go bankrupt.
That exact calculation was done by the Silk Road prosecutors, so we know that 4% of bitcoin transactions were for drugs during the time that marketplace was operating. Whereas for the world economy in general, illegal drugs account for 3% of GDP. It's not an entirely different picture, it's the same picture.
> Oddly, when I hand over a $10 bill, a real piece of money, it doesn't cost me a cent to make my transaction and it's untraceable as to who used it.
Actually, you pay for that piece of paper over time, because the Treasury Department has to keep printing new ones to replace the ones that wear out, and printing and distributing cash costs money. It's buried in your federal taxes. Also, paper money isn't untraceable. Large bills go through readers that record the serial numbers, and can link that to who deposited or withdrew it. So if you got your $10 at a cash machine, and the person who you gave it to put it back in another bank, they can figure out who made a transaction with who. Generally they don't bother to track $10 transactions, but pull out or deposit thousands in cash, and you can bet they track it.
Bitcoin was designed as electronic cash, it says so on the original white paper. It was designed to overcome the locality limitations of paper money. Try sending $10 in cash from the US to Indonesia in under an hour. With the Bitcoin Network you can do that. With Western Union, not so much.
Floriculture, the raising of flowers for sale, is a $100 billion a year business. That includes tulips. Just because tulips were overpriced once upon a time, or dotcom stocks or real estate more recently, does not mean they have no value.
CEO's are not hundreds of times smarter or more productive than the average person. A few times, yes. The reason people higher up in a corporation get paid more is so the people under them have an incentive to work hard and get promoted. But doubling salary for every two levels of management (40% per level) is quite enough incentive to produce the desired hard work in underlings. What's happened in the last few decades is top executives enriching themselves at the expense of the shareholders by ratcheting up their salaries faster than necessary. They do this by surveys and compensation committees who find out the average for similarly positioned executives, and then convincing the board that they need to pay a little more than average to get good talent. Thus the average goes up for the next round. But the quality of the talent doesn't actually go up, they are just paying more for it.
> Sure you can cover the surface of the Earth in solar panels I suppose,
Solar flux arriving at the Earth's surface is 25,000 TW, accounting for night and weather. That's 1400 times more than civilization's total energy consumption from all sources of 18 TW. Throw in other sources like wind, hydroelectric, nuclear, and biofuels, and you maybe need to cover 1/40th of 1% of the Earth. That's about 1/6th of the land area already covered by cities, so you can provide most of the needed area from rooftops and parking lots.
Wind turbines in agricultural areas only use about 1% of the land, because they have to be ~5 blade diameters apart to not shadow the next turbine in the wind farm, and they are built as towers with thin blades. So you can farm nearly up to their base. Offshore turbines don't consume any land at all.
No, a literal rocket scientist, as in advanced space propulsion for Boeing. Tom Murphy, the author of the articles you linked to, is an ivory tower academic. He has no idea about engineering and economics. I can do back-of-the-envelope calculations like he does in those articles, but I have an understanding of the field and which calculations are important. He does not.
I bet you didn't know the energy cost of reaching low Earth orbit (32 MJ/kg), at wholesale electric rates, is half the cost of potatoes/kg at the supermarket. We've just been incredibly wasteful and inefficient in how we go about it till now. If we could merely equal the efficiency of an average automobile, cost to orbit would be 2-3 times potato cost, which is trivial.
Having spent a career in aerospace, I think I'm qualified to answer your untutored questions:
> Send up massive amounts of material, to do something "heavy" in free fall
No, space industry is based on using materials already in space, the Moon and Near Earth Asteroids to start with, because it takes less energy to get them from there than from Earth. The first product is *fuel*, used to deliver and maintain the orbits of the 1250 active satellites in Earth orbit. After that comes maintenance of the satellites when they break. Lack of fuel and broken parts force the replacement of entire satellites, at a cost of billions a year.
> Or the massive amount of rocket exhaust would be just great for the environment?
The most efficient rocket fuel in general use is H2 + O2, whose exhaust is water. SpaceX's rockets use kerosine + O2, but they could probably be made to run on biofuels from plants.
> loonacies like Space Elevators
I taught a class on them last summer. They're quite feasible with proper engineering, which unfortunately the popular descriptions are not:
Moving 1000 tons of asteroid rock to near-Lunar orbit counts as heavy in my book. So does processing that rock to useful products.
You guys who arm-wave 3D printing always seem to forget you need spools of plastic filament or other material to feed the printer, and power to run it. If you supply those at more than hobbyist scale, it becomes heavy industry.
People forget that the first DVD players, in 1997, were $1000, which would be $1250 in this year's dollars. It came down rapidly because a DVD player doesn't have that much expensive hardware in it. Neither does the Oculus Rift, so it and competitors should come down in price fairly fast in a few years.
The audience sits in front of the main set for the show, but they have monitors above that, and can see the camera shots from the other sets. They do multiple takes, so recording takes all day, which means the audience has to laugh at the same jokes multiple times. Often they don't the 15th take. So just like they pick and choose the best camera shots and takes from the actors, they also pick and choose the best laughs from the audience. It all gets edited together later.
If there's an outside scene, that's recorded ahead of time, and played back at an appropriate time for the audience. Many shows use *paid* audiences, who are good at laughing at the right times, and have good sounding laughs. I don't know if BBT does that, but it is common in the industry. Both the camera crew and actors move from set to set, so when it's not the main set in front of the audience, that's empty and dark, and they are just watching the screens.
You guys are overthinking the problem. If you want to shoot down an airliner, build an air cannon, set it up under the approach path to an airport, and lob explosives or ball bearings into the plane's path. The pumpkin throwing contests reached almost a mile with an 8 lb projectile, which is plenty of range. Smart ECM is of no use if you are throwing a dumb projectile.
The best propulsion system I know of (and I wrote a wikibook on the subject: https://en.wikibooks.org/wiki/... ), is using the Sun as a gravitational lens to focus a very powerful laser on the ship. The ship uses the energy to power a particle accelerator. This has better performance than matter-antimatter propulsion because:
* Antimatter annihilation is theoretically 100% conversion of mass to energy, but storing the antimatter is likely to require massive overhead. So the system level matter to energy conversion is going to be much less than 100%. I'd be surprised if you could reach 10%.
* If the energy is coming from an outside source like the Sun, there is no upper bound to how much you can use, even more than 100% matter to energy conversion.
* If your fuel is accelerated to relativistic speed in a particle accelerator, then thrown out as exhaust, it will gain mass according to Relativity. So you can eject more mass than you start with in your tanks.
We know that gravitational lensing works, astronomers use it all the time. Since the Sun makes an enormous lens, it can focus on a small target, even at interstellar distances. To slow down at the end of the trip, keep your beam collector pointed at the Sun, but flip the particle accelerator to point forward,
It's pulled from someone's rear. We have ion thrusters with an exhaust velocity of ~50 km/s that exist today, and prospects to get up to 100 km/s with a little work (little on the scale of the NASA budget). We also have nuclear reactors on ships for many decades, to supply power for the thrusters. Assuming you have mass ratios of 10 for speeding up and slowing down, giving the ship a total mass ratio of 100, you can reach 2.3x exhaust velocity = 230 km/s = 1 light year per 1300 years. So Proxima, at 4.3 LY, is a 5,600 year trip.
However, given a civilization that is making progress, like ours is, it does not make sense to plan a 5,600 year trip. If your propulsion gets only 1% faster a year, waiting a year knocks 56 years off the trip time, and you arrive 55 years sooner. It makes sense to wait until (a) you can make the trip in a short enough time that a faster ship launched later won't pass you, or (b) technology has become stagnant. In case (a) that means a trip that is less than 1.4x, where 1/x is the rate of improvement in technology per year.
Trips measured in thousands of years are non-starters. Assuming your civilization is making progress, at say 1-2% a year, then it does not make sense to plan trips much longer than their inverse, or 50-100 years. Using the 2% example, in 35 years you expect to have a ship twice as fast, which in another 35 years will pass the slower ship (traveling 35 years at 2v, while the slower one went 70 years at v = same distance). So judge the pace of technology, and if it is improving, wait until you can build fast enough ships. If technology plateaus, then you might as well go ahead and launch with what you have.
Wind turbines are giant mixing blades. Downstream from a turbine there are turbulent vortexes that mix with higher layers of air, renewing the wind speed at ground level. That's why a wind farm spaces the turbines about 5 diameters apart, to allow time for the mixing.
Yes, turbines extract some energy from the wind, and slow it down a bit, but they do so from a thicker layer of air than they are tall, and wind speeds at higher altitudes are faster than at ground level. Hills and trees produce friction, and slow down surface winds.
Amen. I got nastygrams from the lady who runs the subdivision HOA, and *I'm not even in the subdivision*, I'm next door. The land she was complaining about isn't my land either, it's city-owned green space.
How is this different than a Silicon Valley startup where the founders and venture capitalists who got in early stand to get a lot of money from the IPO, extracted from later investors?
Early adopters of bitcoin had no assurance bitcoin would be worth anything at all. It was over a year before the first real world purchase happened (Two Papa John pizzas for 10,000 BTC), and a year and a half before they traded for over one cent.
Until a market developed for using them, they were just a cryptographic curiosity. There was no assurance the software would reach a usable and secure form, ever.
It's quite easy to defeat that kind of tracking. Send your coins to a bitcoin exchange, and sell them for currency. Later trade back to bitcoin and pull your funds out, typically on a different address.
Another way is to trade on localbitcoins.com for paper cash. The coins now belong to an unconnected person.
Finally, people run "tumbler" services, where multiple people put in funds, they are randomly sent through various addresses, and finally go back to the original people, but in random amounts to different addresses (addresses are essentially free to create).
> It doesn't require rare earth metals like a photovoltaic setup would.
PV panels don't need rare earths. They are made of silicon (for the cells), plus trace elements like Phosphorus to provide the right semiconductor properties. The frame is aluminum and glass, with typically polyvinylacetate (plastic) backing sheet. You need wires to connect the cells to each other, and then the panels to each other. The mounting for the panels is typically steel or aluminum, with some concrete to anchor it to the ground.
Tracking mounts are becoming more popular, those follow the Sun to get more output from the panels. That adds a motor to a group of panels so they can move, but it doesn't have to be a fancy rare earth magnet. The tracking motion is as fast as the Sun moves, so it's a pretty small motor.
You may be thinking of wind turbines, which *do* sometimes use rare-earth magnets in their generators. The generator handles 1.5 to 3 MW these days for commercial wind turbines, and it has to be installed on top of a ~120 meter tall post. So reducing weight is important.
Slashdot Mirror
A 10 ton asteroid tug with 20-25 tons of fuel can return about 1000 tons of asteroid rock to a high orbit, such as near the Moon. That's enough to shield a few Deep Space Habitat modules. Assume the modules are Space Station-sized, about 5x10 m cylinders. You want 1 meter of shielding, which is then a cylinder 7x10 meters, or 188 cubic meters. Chondrite type meteorites have a solid density of 2-3 tons/cubic meter, so the mass would be 375 to 560 tons. So you can cover roughly 2-3 modules. You build a cylinder of storage lockers around the pressure shell of the module, stuff each locker with rocks, and you are done.
The tug takes about 2 years to make the trip to a good Near Earth Asteroid, though the trip time will depend on which asteroid and when you leave. Because you want to use it as shielding, you grab dust and small rocks off the asteroid surface, and not big chunks. Later you can process the rock to extract water and other useful stuff. Since the tug's engines and solar arrays have a life of ~15 years, you can make multiple trips. The first one is for shielding, the ones after that are for processing.
10 tons of vehicle hardware should cost about two large comsats, or ~$600 million. It's mostly solar arrays and electric propulsion units, with enough multiples of each that a failure or two doesn't doom the mission. Each time the tug returns, you can fix whatever breaks before the next trip. The first load of propellant has to come from Earth, but the later trips can use water extracted from your asteroid rock.
> I do wonder how feasible it would be to build some sort of a hydraulically stabilized landing platform on top of the barge
Look up "Sea Launch", which was a partnership between Boeing, Kvaerner A.G. (Norwegian ship and drilling platform builder), and Russian rocket companies. They launched rockets from a converted drilling platform out in the Pacific Ocean.
A semi-submersible platform like that takes on ballast water to lower the center of mass below the waves, while the platform on top is held *above* the water on columns. The waves can then pass through the columns without moving the platform much, because it's not a solid wall like the side of a ship. The ballast water mass also makes the whole platform more massive and hard to move.
Right now (or very soon) you will likely be able to pick up drilling platforms for scrap value. With the price of oil so low, expensive ways to extract oil, like fracking and ocean drilling, can't make a profit, so the drilling companies stop doing it, and some of them go bankrupt.
That exact calculation was done by the Silk Road prosecutors, so we know that 4% of bitcoin transactions were for drugs during the time that marketplace was operating. Whereas for the world economy in general, illegal drugs account for 3% of GDP. It's not an entirely different picture, it's the same picture.
> Oddly, when I hand over a $10 bill, a real piece of money, it doesn't cost me a cent to make my transaction and it's untraceable as to who used it.
Actually, you pay for that piece of paper over time, because the Treasury Department has to keep printing new ones to replace the ones that wear out, and printing and distributing cash costs money. It's buried in your federal taxes. Also, paper money isn't untraceable. Large bills go through readers that record the serial numbers, and can link that to who deposited or withdrew it. So if you got your $10 at a cash machine, and the person who you gave it to put it back in another bank, they can figure out who made a transaction with who. Generally they don't bother to track $10 transactions, but pull out or deposit thousands in cash, and you can bet they track it.
Bitcoin was designed as electronic cash, it says so on the original white paper. It was designed to overcome the locality limitations of paper money. Try sending $10 in cash from the US to Indonesia in under an hour. With the Bitcoin Network you can do that. With Western Union, not so much.
Floriculture, the raising of flowers for sale, is a $100 billion a year business. That includes tulips. Just because tulips were overpriced once upon a time, or dotcom stocks or real estate more recently, does not mean they have no value.
CEO's are not hundreds of times smarter or more productive than the average person. A few times, yes. The reason people higher up in a corporation get paid more is so the people under them have an incentive to work hard and get promoted. But doubling salary for every two levels of management (40% per level) is quite enough incentive to produce the desired hard work in underlings. What's happened in the last few decades is top executives enriching themselves at the expense of the shareholders by ratcheting up their salaries faster than necessary. They do this by surveys and compensation committees who find out the average for similarly positioned executives, and then convincing the board that they need to pay a little more than average to get good talent. Thus the average goes up for the next round. But the quality of the talent doesn't actually go up, they are just paying more for it.
Correct. It's not how much you earn, it's how much you keep. Your savings then start earning for you, and eventually you don't have to work any more.
> Sure you can cover the surface of the Earth in solar panels I suppose,
Solar flux arriving at the Earth's surface is 25,000 TW, accounting for night and weather. That's 1400 times more than civilization's total energy consumption from all sources of 18 TW. Throw in other sources like wind, hydroelectric, nuclear, and biofuels, and you maybe need to cover 1/40th of 1% of the Earth. That's about 1/6th of the land area already covered by cities, so you can provide most of the needed area from rooftops and parking lots.
Wind turbines in agricultural areas only use about 1% of the land, because they have to be ~5 blade diameters apart to not shadow the next turbine in the wind farm, and they are built as towers with thin blades. So you can farm nearly up to their base. Offshore turbines don't consume any land at all.
> I'd bet you're a programmer?
No, a literal rocket scientist, as in advanced space propulsion for Boeing. Tom Murphy, the author of the articles you linked to, is an ivory tower academic. He has no idea about engineering and economics. I can do back-of-the-envelope calculations like he does in those articles, but I have an understanding of the field and which calculations are important. He does not.
I bet you didn't know the energy cost of reaching low Earth orbit (32 MJ/kg), at wholesale electric rates, is half the cost of potatoes/kg at the supermarket. We've just been incredibly wasteful and inefficient in how we go about it till now. If we could merely equal the efficiency of an average automobile, cost to orbit would be 2-3 times potato cost, which is trivial.
Having spent a career in aerospace, I think I'm qualified to answer your untutored questions:
> Send up massive amounts of material, to do something "heavy" in free fall
No, space industry is based on using materials already in space, the Moon and Near Earth Asteroids to start with, because it takes less energy to get them from there than from Earth. The first product is *fuel*, used to deliver and maintain the orbits of the 1250 active satellites in Earth orbit. After that comes maintenance of the satellites when they break. Lack of fuel and broken parts force the replacement of entire satellites, at a cost of billions a year.
> Or the massive amount of rocket exhaust would be just great for the environment?
The most efficient rocket fuel in general use is H2 + O2, whose exhaust is water. SpaceX's rockets use kerosine + O2, but they could probably be made to run on biofuels from plants.
> loonacies like Space Elevators
I taught a class on them last summer. They're quite feasible with proper engineering, which unfortunately the popular descriptions are not:
https://en.wikibooks.org/wiki/...
Moving 1000 tons of asteroid rock to near-Lunar orbit counts as heavy in my book. So does processing that rock to useful products.
You guys who arm-wave 3D printing always seem to forget you need spools of plastic filament or other material to feed the printer, and power to run it. If you supply those at more than hobbyist scale, it becomes heavy industry.
Have a read about self-bootstrapping industry in space: https://en.wikibooks.org/wiki/...
People forget that the first DVD players, in 1997, were $1000, which would be $1250 in this year's dollars. It came down rapidly because a DVD player doesn't have that much expensive hardware in it. Neither does the Oculus Rift, so it and competitors should come down in price fairly fast in a few years.
The audience sits in front of the main set for the show, but they have monitors above that, and can see the camera shots from the other sets. They do multiple takes, so recording takes all day, which means the audience has to laugh at the same jokes multiple times. Often they don't the 15th take. So just like they pick and choose the best camera shots and takes from the actors, they also pick and choose the best laughs from the audience. It all gets edited together later.
If there's an outside scene, that's recorded ahead of time, and played back at an appropriate time for the audience. Many shows use *paid* audiences, who are good at laughing at the right times, and have good sounding laughs. I don't know if BBT does that, but it is common in the industry. Both the camera crew and actors move from set to set, so when it's not the main set in front of the audience, that's empty and dark, and they are just watching the screens.
You guys are overthinking the problem. If you want to shoot down an airliner, build an air cannon, set it up under the approach path to an airport, and lob explosives or ball bearings into the plane's path. The pumpkin throwing contests reached almost a mile with an 8 lb projectile, which is plenty of range. Smart ECM is of no use if you are throwing a dumb projectile.
The best propulsion system I know of (and I wrote a wikibook on the subject: https://en.wikibooks.org/wiki/... ), is using the Sun as a gravitational lens to focus a very powerful laser on the ship. The ship uses the energy to power a particle accelerator. This has better performance than matter-antimatter propulsion because:
* Antimatter annihilation is theoretically 100% conversion of mass to energy, but storing the antimatter is likely to require massive overhead. So the system level matter to energy conversion is going to be much less than 100%. I'd be surprised if you could reach 10%.
* If the energy is coming from an outside source like the Sun, there is no upper bound to how much you can use, even more than 100% matter to energy conversion.
* If your fuel is accelerated to relativistic speed in a particle accelerator, then thrown out as exhaust, it will gain mass according to Relativity. So you can eject more mass than you start with in your tanks.
We know that gravitational lensing works, astronomers use it all the time. Since the Sun makes an enormous lens, it can focus on a small target, even at interstellar distances. To slow down at the end of the trip, keep your beam collector pointed at the Sun, but flip the particle accelerator to point forward,
It's pulled from someone's rear. We have ion thrusters with an exhaust velocity of ~50 km/s that exist today, and prospects to get up to 100 km/s with a little work (little on the scale of the NASA budget). We also have nuclear reactors on ships for many decades, to supply power for the thrusters. Assuming you have mass ratios of 10 for speeding up and slowing down, giving the ship a total mass ratio of 100, you can reach 2.3x exhaust velocity = 230 km/s = 1 light year per 1300 years. So Proxima, at 4.3 LY, is a 5,600 year trip.
However, given a civilization that is making progress, like ours is, it does not make sense to plan a 5,600 year trip. If your propulsion gets only 1% faster a year, waiting a year knocks 56 years off the trip time, and you arrive 55 years sooner. It makes sense to wait until (a) you can make the trip in a short enough time that a faster ship launched later won't pass you, or (b) technology has become stagnant. In case (a) that means a trip that is less than 1.4x, where 1/x is the rate of improvement in technology per year.
Trips measured in thousands of years are non-starters. Assuming your civilization is making progress, at say 1-2% a year, then it does not make sense to plan trips much longer than their inverse, or 50-100 years. Using the 2% example, in 35 years you expect to have a ship twice as fast, which in another 35 years will pass the slower ship (traveling 35 years at 2v, while the slower one went 70 years at v = same distance). So judge the pace of technology, and if it is improving, wait until you can build fast enough ships. If technology plateaus, then you might as well go ahead and launch with what you have.
You may be interested in this report I'm working on:
https://en.wikibooks.org/wiki/...
Rather than one or two places, it envisions settling the whole Solar System using networks of self-replicating factories.
Wind turbines are giant mixing blades. Downstream from a turbine there are turbulent vortexes that mix with higher layers of air, renewing the wind speed at ground level. That's why a wind farm spaces the turbines about 5 diameters apart, to allow time for the mixing.
Yes, turbines extract some energy from the wind, and slow it down a bit, but they do so from a thicker layer of air than they are tall, and wind speeds at higher altitudes are faster than at ground level. Hills and trees produce friction, and slow down surface winds.
Amen. I got nastygrams from the lady who runs the subdivision HOA, and *I'm not even in the subdivision*, I'm next door. The land she was complaining about isn't my land either, it's city-owned green space.
How is this different than a Silicon Valley startup where the founders and venture capitalists who got in early stand to get a lot of money from the IPO, extracted from later investors?
Early adopters of bitcoin had no assurance bitcoin would be worth anything at all. It was over a year before the first real world purchase happened (Two Papa John pizzas for 10,000 BTC), and a year and a half before they traded for over one cent.
Until a market developed for using them, they were just a cryptographic curiosity. There was no assurance the software would reach a usable and secure form, ever.
Ah, but the irony of a system that eliminates the need for banks as middlemen being nominated for a banker's prize is delicious.
It's quite easy to defeat that kind of tracking. Send your coins to a bitcoin exchange, and sell them for currency. Later trade back to bitcoin and pull your funds out, typically on a different address.
Another way is to trade on localbitcoins.com for paper cash. The coins now belong to an unconnected person.
Finally, people run "tumbler" services, where multiple people put in funds, they are randomly sent through various addresses, and finally go back to the original people, but in random amounts to different addresses (addresses are essentially free to create).
> It doesn't require rare earth metals like a photovoltaic setup would.
PV panels don't need rare earths. They are made of silicon (for the cells), plus trace elements like Phosphorus to provide the right semiconductor properties. The frame is aluminum and glass, with typically polyvinylacetate (plastic) backing sheet. You need wires to connect the cells to each other, and then the panels to each other. The mounting for the panels is typically steel or aluminum, with some concrete to anchor it to the ground.
Tracking mounts are becoming more popular, those follow the Sun to get more output from the panels. That adds a motor to a group of panels so they can move, but it doesn't have to be a fancy rare earth magnet. The tracking motion is as fast as the Sun moves, so it's a pretty small motor.
You may be thinking of wind turbines, which *do* sometimes use rare-earth magnets in their generators. The generator handles 1.5 to 3 MW these days for commercial wind turbines, and it has to be installed on top of a ~120 meter tall post. So reducing weight is important.
Negotiated in secret, without even elected representatives able to review it? I will break it in secret - seems fair to me.