Live-action remake of "Heavy Metal."
That may be a good reason! It depends on the actresses.
Space Based Solar Power
- Thread starter publiusr
- Start date
Fair point
I think that it's totally impractical.
Let's see where launch costs are now.
Capabilities & Services | SpaceX -- SpaceX gives us some numbers for its Falcon 9 rocket.
Cost: $61.2 million
Low Earth Orbit (inc = 28.5d): 13.150 mt
Geosynchronous Transfer Orbit (inc = 27d): 4.850 mt
Cost/kg (LEO): $4,700
Cost/kg (GTO): $12,600
The orbit inclinations are consistent with the launch site being Cape Canaveral. SpaceX can also launch from Vandenberg Air Force Base in California, but that's most suitable for high-inclination orbits.
Let's now consider a typical solar panel.
Solarfennel 250W PS6A-250 Poly Silver Frame Solar Panel - Solarfennel - English | ACOSolar.com
Cost: $175
Maximum electrical power: 250 watts
Mass: 20 kg
PV cells: 60 of 156 mm * 156 mm
(Found with google.com/shopping)
Cost/kg: $8.75
Power/kg: 12.5 watts
Power/m^2: 171 watts
Surface density: 14 kg/m^2
Solar flux at the Earth's mean distance: 1361 watts/m^2 (min activity), 1362 watts/m^2 (max activity).
Efficiency: 12.6%
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Let's now consider humanity's total electricity (Electric energy consumption for 2008) and oil (Petroleum for 2011) consumption, the latter scaled with Barrel of oil equivalent (1 barrel = 6.1178632 gigajoules). These are all in terawatts.
Region | Electricity | Oil
World | 2.31 | 6.19
US | 0.50 | 1.33
EU | 0.41 | 0.97
There is some overlap between electricity and oil, but not much. The lower rate of consumption for electricity is because of inefficiencies in fossil-fuel generation (World energy consumption). The total from all "raw" sources is 18.0 terawatts.
Having gotten some targets, we can now calculate how much solar panel is necessary.
For 1 terawatt and 10 watts/kg, that is 10^11 kg of solar panel, or 10^8 metric tons.
Let's see how good that one might be able to get. Consider a 1-mm thick solar panel with silicon's density: 2.32 g/cm^3, and imagine that it does not have much extra mass of structural material.
That's a surface density of about 2 kg/m^2, a factor of 7 improvement. That would mean 1.4*10^7 metric tons.
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So to replace all of humanity's existing sources, one would need something like 10^(8 - 9) metric tons of solar panel. With SpaceX's launch costs of about $5*10^6 per mt, that becomes $500 - $5000 trillion. But if an Earth-based system costs only $10,000 per mt, as I'd estimated earlier, that because $1 - $10 trillion. So if we ever succeed in building enough space-based manufacturing capability to make launch costs irrelevant, Earth-based systems will have taken over long ago.
Let's see where launch costs are now.
Capabilities & Services | SpaceX -- SpaceX gives us some numbers for its Falcon 9 rocket.
Cost: $61.2 million
Low Earth Orbit (inc = 28.5d): 13.150 mt
Geosynchronous Transfer Orbit (inc = 27d): 4.850 mt
Cost/kg (LEO): $4,700
Cost/kg (GTO): $12,600
The orbit inclinations are consistent with the launch site being Cape Canaveral. SpaceX can also launch from Vandenberg Air Force Base in California, but that's most suitable for high-inclination orbits.
Let's now consider a typical solar panel.
Solarfennel 250W PS6A-250 Poly Silver Frame Solar Panel - Solarfennel - English | ACOSolar.com
Cost: $175
Maximum electrical power: 250 watts
Mass: 20 kg
PV cells: 60 of 156 mm * 156 mm
(Found with google.com/shopping)
Cost/kg: $8.75
Power/kg: 12.5 watts
Power/m^2: 171 watts
Surface density: 14 kg/m^2
Solar flux at the Earth's mean distance: 1361 watts/m^2 (min activity), 1362 watts/m^2 (max activity).
Efficiency: 12.6%
-
Let's now consider humanity's total electricity (Electric energy consumption for 2008) and oil (Petroleum for 2011) consumption, the latter scaled with Barrel of oil equivalent (1 barrel = 6.1178632 gigajoules). These are all in terawatts.
Region | Electricity | Oil
World | 2.31 | 6.19
US | 0.50 | 1.33
EU | 0.41 | 0.97
There is some overlap between electricity and oil, but not much. The lower rate of consumption for electricity is because of inefficiencies in fossil-fuel generation (World energy consumption). The total from all "raw" sources is 18.0 terawatts.
Having gotten some targets, we can now calculate how much solar panel is necessary.
For 1 terawatt and 10 watts/kg, that is 10^11 kg of solar panel, or 10^8 metric tons.
Let's see how good that one might be able to get. Consider a 1-mm thick solar panel with silicon's density: 2.32 g/cm^3, and imagine that it does not have much extra mass of structural material.
That's a surface density of about 2 kg/m^2, a factor of 7 improvement. That would mean 1.4*10^7 metric tons.
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So to replace all of humanity's existing sources, one would need something like 10^(8 - 9) metric tons of solar panel. With SpaceX's launch costs of about $5*10^6 per mt, that becomes $500 - $5000 trillion. But if an Earth-based system costs only $10,000 per mt, as I'd estimated earlier, that because $1 - $10 trillion. So if we ever succeed in building enough space-based manufacturing capability to make launch costs irrelevant, Earth-based systems will have taken over long ago.
I gave the lowball figures on the previous page, just accounting for launch costs and assuming a "starter" powersat or powersat array. My high-ball figure with "real world" technology is actually similar to yours, except I based the launch costs on the Space Shuttle payload rate (assuming somebody is using the SLS for the launch and deployment and assuming SLS is as efficient as the STS). Even ignoring the actual development and construction costs, I estimated the cost of launching the solar panels plus the mass of supporting truss and power conditioning hardware to be:
$420 billion.
But that, again, is for a "starter" powersat in the 300MWe range (about 1.5 million square meters of solar array plus 50 to 80 metric tons of supporting trusses and power conditioning modules). I realize you're calculating the cost for a satellite that could provide ALL of humanity's power consumption needs, but the picture is way bleaker than that: just a MODEST powersat like the one described would wind up being the most expensive manmade object ever conceived.
So, yes, totally impractical on just about any scale with current technology, and even a tenfold improvement in launch costs AND solar panel efficiency wouldn't make it a profitable endeavor.
We spent more than the Marshall plan overseas with less results
http://www.latimes.com/world/afghan...fghanistan-us-aid-outlook-20140731-story.html
F-35 alone will cost three times your 420 billion estimate on SPSS
http://www.theatlantic.com/video/index/384088/the-pentagons-15-trillion-mistake/
I'll take that--and nix the other two. And have money to spare.
It might not power everything--but--like Apolloo--it will inspire.
http://www.latimes.com/world/afghan...fghanistan-us-aid-outlook-20140731-story.html
F-35 alone will cost three times your 420 billion estimate on SPSS
http://www.theatlantic.com/video/index/384088/the-pentagons-15-trillion-mistake/
I'll take that--and nix the other two. And have money to spare.
It might not power everything--but--like Apolloo--it will inspire.
Mass production can drive that cost down. I thought we wanted more launches and business for spaceflight.
Now if you'd rather have the same or more money on the Pentagon's endless wish list--be my guest.
So help me--but space advocates have become their own worst enemy--sniping on big projects the L5 folks used to push when politicians weren't listening.
Congress is about as pro-space as they have ever been--and here we are in a circular firing squad.
Now if you'd rather have the same or more money on the Pentagon's endless wish list--be my guest.
So help me--but space advocates have become their own worst enemy--sniping on big projects the L5 folks used to push when politicians weren't listening.
Congress is about as pro-space as they have ever been--and here we are in a circular firing squad.
Wasting the money they do get on a pointless project such as this would not help our future in space since. Given how much cheaper ground based solar is, the benefits of having it done in space cannot compete yet. As well, your argument assumes that not spending the money on space solar power means we have to spend it on the military instead of some other project in space. Why would that be the case? One thing we do not have is a shortage of excellent proposals for what we could be doing if we had the funding.
Not if you're using the SLS.
"Circular firing squad" because we are torpedoing an idea that makes no economic sense, has no net benefit to humanity, will consume financial and military resources hundreds of times beyond anything America has ever spent on space, and that no one in NASA or the aerospace community even wants to try?
There are stupider things to try and push Congress to do for the sake of space exploration, but they all involve porn.
About 20 years ago, a friend of mine told me that someone had come to the conclusion that the cheapest thing to return from outer space is information. It's rather paradoxical, but I agreed then, and I still agree now.
For returning information, all one needs is a radio transmitter, and a spacecraft will almost certainly have one for reporting on its status, if nothing else. Furthermore, if a spacecraft only returns information, none of it has to return home. Returning physical entities like rocks or astronauts is much more difficult, because at least part of the spacecraft must carry them home. That requires additional rocket fuel, additional spacecraft structure, and a more complicated mission.
Here are the most successful applications of spaceflight so far:
The most common physical entities returned are
For returning information, all one needs is a radio transmitter, and a spacecraft will almost certainly have one for reporting on its status, if nothing else. Furthermore, if a spacecraft only returns information, none of it has to return home. Returning physical entities like rocks or astronauts is much more difficult, because at least part of the spacecraft must carry them home. That requires additional rocket fuel, additional spacecraft structure, and a more complicated mission.
Here are the most successful applications of spaceflight so far:
- Communications relaying
- Navigation beacons (GPS)
- Earth observation: weather, land mapping, resources, and espionage
- Astronomical observation
- Interplanetary exploration
The most common physical entities returned are
- Astronauts (cosmonauts, etc.)
- Exposed film (common in the earlier spy satellites)
- Extraterrestrial materials: Moon rocks, asteroid material, interplanetary dust, solar wind
Ground based solar isn't going to help space--SPSS will. That and beamed propulsion will have a lot in common.
ground based power competes against funding for asteroids deflection, say
Folks are looking at that for laser defense at the least.
http://nextbigfuture.com/2016/04/all-of-technology-is-nearly-ready-for.html
"...though due to the reduced mass of DE-STARLITE, a much larger PV array can be deployed within the SLS block 1 mass allocation (70 tons to LEO) if desired."
Yes--because of SLS. More flights are what you want for costs to come down. Again--Webb is costly because it lacks an HLLV
"Our commitment to simplicity is based on the analysis of David Beardon. Beardon has shown that there is a direct correlation between mission payload complexity and total mission cost...Given the available mass and volume capacity of the SLS, some subsystems may be able to use simpler more-mature (and more massive) technologies or higher design rule margins to eliminate complexity, lower risk and lower cost."
http://asd.gsfc.nasa.gov/ATLAST/tech/Stahl_SPIE_2015_paper.pdf
Humanity enjoys spaceflight despite economic sense, not because of it.
http://www.amazon.com/Rockets-Revolution-Cultural-History-Spaceflight/dp/0803255225
Again--take the Very Light Jet/Air Taxi model. Folks complained about gov't bailed out--union infested airlines. Poor service, no legroom. They all thought that the great god "market" was the answer. But venture capitalists are actually very risk averse. When it came time to pony up the large up-front costs associated with aviation and aerospace--most balked--and the air-taxi model died on the vine.
But R-7 was pushed by national pride. You didn't have to go on Shark Tank and beg. Vision and national pride got us to space to begin with--the economics followed
That's what they said about the space shuttle originally. History showed these claims to be untrue: even at the zenith of the shuttle program, when NASA was able to manage 5 or 6 launches per year, they still weren't getting their costs down below about $600 million per launch. This with the shuttle orbiter -- and its engines -- being fully reusable. SLS doesn't have a reusable upper stage or reusable engines, which means NASA has to rebuild and re-certify the entire thing every time they launch one.
More importantly, the high costs of the shuttle program were a feature, not a bug. They were built into the service contracts -- with ATK in particular -- so that if and when the contractors found cheaper ways of providing those services they got to keep the profits themselves.
Which means even if the cost of the SLS goes down because of an economy of scale, NASA doesn't get to benefit from the savings unless they renegotiate the contracts. Which they won't, because setting up those contracts for maximum profitability is the whole reason SLS was created.
Incorrect: The Jim Webb telescope has already cost over $8 billion JUST TO BUILD IT. The SLS program has nothing to do with it.
All of which is functionally irrelevant. Even if NASA could build orbital solar platforms using Falcon-9 rockets -- which, combined with modular construction, can outperform SLS in nearly every capacity -- they'd still wind up with $10 billion in launch costs for a powerplant that barely outperforms a $400 million ground-based solar collector.
Economically speaking, this is like buying a helicopter for pizza deliveries. It's both harder to use and more expensive than any NORMAL solution, and there's no reason to do it except because it would be cool.
If you want to "enjoy spaceflight," go play a fucking videogame. When we start doing ACTUAL WORK in space, then we'll have a reason to live there.
No, take the telecom model. Companies like orbital sciences have developed new spacecraft buses, new technologies, new standards, new systems, and have been using them in space for half a century. Communication satellites are big business. They are valuable commodities and worthwhile investments, and because of this the United States has launched THOUSANDS of them into orbit since the space age began. We overlook this fact because unmanned spacecraft aren't as glamorous or fancy as manned ones, but it remains the case that the privatization of space exploration has been well underway since at least the Gemini program.
Privatization of launch services came next, first with the Titan family and later with the Ariane series. So now the only question is the privatization of MANNED spaceflight. Anyone can launch a satellite into orbit, but not everyone can launch payloads or crews to a space station. To that end, SapceX and Orbital Sciences took the next step and developed a revolutionary new launch system that meets the government's very specific needs. If you expand those needs, companies like SpaceX and Orbital Sciences can expand their services and their capabilities. When they can do more things for less money, they can offer more of those services to additional customers, and providing more of those services continues to expand their capabilities.
You're essentially arguing against the last 50 years of space exploration with this claim. Commercial spaceflight is nearly a trillion dollar industry by now; manned spaceflight is a relative new niche in that industry, but the industry ITSELF is already quite mature. And I am telling you that the industry case for orbital solar power is simply non-existent: if anyone anywhere thought it was a good idea, they could have easily done it a dozen times by now. The reason no one wants to is because it costs too much and produces too little to be worth the investment.
No, R-7 was pushed by military necessity and, amusingly, subverted by scientists who had more peaceful purposes in mind.
I wouldn't say subverted. The space activists were the only ones who knew how to build rockets. They could have waited for smaller warheads and storables--but that worked against their interest. They exploited uncle joe's militarism--to get something useful out of the mil-budget.
wink wink--that's what I'm doing here.
The space race was the only good part of the cold war spending.
ironically politicians here hated it the most--like Prox,ire, Mondale, Nixon....
wink wink--that's what I'm doing here.
The space race was the only good part of the cold war spending.
ironically politicians here hated it the most--like Prox,ire, Mondale, Nixon....
Yes, and exploiting a the militaristic wet dreams of a psychopath and redirecting his funding towards a totally different purpose is a frankly EXCELLENT example of what I would call "subversive" behavior. I actually tell that story to my son sometimes, the moral being "When the guy you work for is an asshole, the best thing you can do is make that asshole work for you."
No you're not. Korolev subverted Stalin's militarism by redirecting the funding for an ICBM into a system that worked poorly as an ICBM but excellently as a manned space booster.
You're talking about subverting an industry that has been profitable for 50 years AND sidelining a manned space program that already has a very slim chance of success and redirecting their funding and resources to a technological boondoggle that will never actually profitable and will ultimately serve no purpose except to eventually give the space launch industry a massive orbiting junk pile to have to dispose of.
We HAVE an entire industry that is already fully engaged in space exploration and space exploitation. We HAVE a path towards expanding the human presence in low Earth orbit and eventually on the moon. Why would you want to sidetrack that with a useless project that even industry experts don't want to pursue?
The Pizza Boy doesn't need a helicopter. He needs a faster bicycle and a pay raise.
It cost 8 bil because the damn LV it was going in was too small. That's why it cost so much. size and payload diameter has everything to do with it--thats why Bigelow flew atop Atlas, not Falcon.
Which can never have a side use as a Solar Electric spacecraft Not either or--both and
Which did not exist Ex nihilo, but arouse out of what many thought a costly ICBM program. Actually IRBM--since Deltas a re really stretched Thors
Telecom is onlu going to get you so many payloads on its own. My nightmare situation is for some other means to come along (drones, blimps, neutrino comm, etc) that will devastate the newspace model you have so much faith it. Building larger strutrues in space--for its own sake--is to me a worthy goal--and Elon and others would enjoy the business.
And right now, that is what Coyote Smith is doing
Adding to that industry, actually.
Good. But consider that Korolev was a little more in the drivers seat in some respects than von Braun. The USAF had LeMay. The Navy had Rickover. Medaris was going to be the same for the U.S. Army. The ABMA was to be the big breakout moment.
But it was not to be. All things rocketry and space related were stripped from the ABMA and divvied up between NASA, the USAF.
That was when the cause of space became subverted. Remember, the R-7 handling was done by artillerymen for the longest time. The ABMA model worked better for them.
But even the USAF has some interest:
http://spacefaringinstitute.news/20...n-to-ltc-garretson-discuss-space-solar-power/
The problem is that space advocates are share the same broom closet in the Pentagon--all while fighter jocks and carrier groupies get their endless wish lists. I wish you'd attack that for a change, instead of futurists.
More http://spacefaringinstitute.com/online-resources
http://mikesnead.net/resources/spacefaring/fact-sheet-shuttle-derived-spacelifter-20070809.pdf
In other news, Hu Davis--of the Aquila concept--recently passed away
http://buzzaldrin.com/space-vision/rocket_science/aquila/
http://spacefaringamerica.net/?p=895[/QUOTE]
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1) Bigelow flew on an Atlas because the Falcon wasn't ready to launch it at the time. Falcon's payload faring diameter is actually very similar to the Atlas
2) What you are quoting right now is an SLS talking point with no basis in reality; if the Webb telescope had been designed with a smaller LV in mind, it would already be in orbit by now. The ACTUAL case is that the designers realized a larger HLV might some day become available and then re-designed the system to account for it; the redesigns didn't work correctly and resulted in cost overruns and schedule slips, which is pretty much the motto of American aerospace at this point.
All of which were originally developed by industry FOR the military in the first place. The government gave them assistance in repurposing those missiles into civilian launch programs and they've been profitable ever since.
Is there some military utility of an orbital solar power plant you'd maybe like to share with us?
3,700 and counting.
Sure they would, but that's too expensive of a project just to do it for PRACTICE. Give them a compelling reason to build a larger structure in space and let them make money doing it, and then it will happen. We don't NEED an orbital solar power plant, so there's no reason to gain experience in building them.
You're trying to make the case for spinning off a government program to private industry the same way the Russians did with Roskosmos and the same way the U.S. did with the Titans and Deltas. The only program that fits that description is the ISS; the only way to spin it off the way you're describing is to let industry build up a support infrastructure for space stations and then use that infrastructure to either maintain ISS independently or build their own space stations in low orbit.
NASA obviously agrees with this idea, which is why the last Dragon launch carried a bigelow module to the ISS.
Testbed? With two VASIMR rockets and a thousand square meters of solar array you could send ISS to Mars and back. Why the hell would we waste time dicking around with microwave power transmission at that point?
This is LITERALLY the problem with orbital solar power. By the time we have the infrastructure in place to make it even slightly viable, we won't need it anymore.
It's nothing to do with fusion.
Orbital solar energy is a NOT a profitable endeavor and it never will be. The only reason to do it in the first place -- as you yourself admitted -- is as an excuse to expand humanity's space launch infrastructure and massively expand the spacing industry. Problem is, the kind of industry that would be needed to build a practical solar power satellite is EXACTLY the kind of industry that no longer needs to use it as an excuse.
Your ISS example is a perfect illustrator of this. You propose using ISS as a solar power testbed in order to get the ball rolling on a concept that would promote more use of space infrastructure in the future. But the launch and engineering capabilities needed to convert ISS into a solar power satellite would REQUIRE the very infrastructure you're trying to promote; if you already had that infrastructure in place, there'd be no reason to promote it, you could just USE it.