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This Satellite Could Be Beaming Solar Power Down From Space By 2025
Daniel_Stuckey writes "A NASA veteran, aerospace entrepreneur, and space-based solar power (SBSP) expert, [John] Mankins designed the world's first practical orbital solar plant. It's called the Solar Power Satellite via Arbitrarily Large PHased Array, or SPS-ALPHA for short. If all goes to plan, it could be launched as early as 2025, which is sooner than it sounds when it comes to space-based solar power timelines. Scientists have been aware of the edge the "space-down" approach holds over terrestrial panels for decades. An orbiting plant would be unaffected by weather, atmospheric filtering of light, and the sun's inconvenient habit of setting every evening. SBSP also has the potential to dramatically increase the availability of renewable energy."
A satellite directly beaming solar power down from space? We've created... the moon.
how exactly can it "revolutionize disaster relief" when it needs an almost 40km^2 (6-8km in diameter) receiver array on the ground to get the power beamed from the satellite. Disaster relief means fast deployment. How fast can you deploy a 40km^2 grid on the ground?
not even mentioning the fact that if you had 40km^2 of land you could just set solar panels there and do the thing for yourself with much less energy losses.
Japan is already working on a prototype solar power satellite. The ESA has an active project. I'd hope NASA could work with them on this one.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
The energy needed to put solar cells into orbit is not recouped over their lifetime outside the protecting atmosphere. Solar cells are used on spacecraft out of necessity, not because they're cost efficient.
I know this is an unpopular view on Slashdot, where atomic energy fans come together to bash all other technologies, but solar cells work fine on the ground. You can fill the supply gaps with conventional power plants and still come out far ahead CO2-wise compared to the current power mix. Production has hardly scaled up, but solar cells are already competitive in some markets. The point of these stories about satellite solar farms is to give you the impression that there needs to be some extraordinary investment or innovation before solar power can be used. That's a lie, designed to put a drag on solar power. Solar power is ready to be used, you just have to do it.
would someone please at least a security engineer before they design the control API for the thing?
No. There's no pleasing security engineers.
Scientists point out problems, engineers fix them
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the microwave downlink gets misaligned and burns down the city block next to the ground station.
TFA seems to imply that they considered the issue of using lasers and shot it down with the words:
High frequency blasts can damage retinas, destroy electronics, and potentially ignite fires or explosions. “Think about the Death Star,” he warned. The risk factor outweighs the seductive, compact grace offered by lasers.
As you note, however, microwaves are not entirely safe either. On the other hand, if the intensity is low enough it should be safe, which is what is being discussed:
Since Mankins is dead-set on low-intensity microwave transmitters, the receiver on Earth will be large—about 6 to 8 km in diameter, positioned 5 to 10 meters above the ground.
The obvious question is if the beams can be focused, and used as a weapon, it could provide a no-warning and very destructive attack anywhere in the world. It seems to be what Mankins is trying to avoid, and I tend to agree that (aside from cost) we really, really need to make sure that the power sources of the future are not just being used to cloak the real objective: Making powerful weapons. Example: Nuclear power.
The truth may be out there, but lies are inside your head
Energy is life and civilization. Balancing an industrial society on the razor edge of a single point of failure is itself a 'fail'. Whether the failure would occur technically or politically is of little consequence.
The catch-22 is impossible to avoid. If orbital solar doesn't scale then it is a waste of resource, if it does then it's a single point of (catastrophic) failure.
Terrestrial power plants can be replicated easily, hardened from sabotage, operated and maintained within many sovereign countries at once, can easily swap out parts. That is what you would wish to ensure the future.
http://www.youtube.com/watch?v=lG1YjDdI_c8
<blink>down the rabbit hole</blink>
It seems like the fear of weaponisation is whats kept this sort of thing from being explored more fully, up till now of course, but I think that there are logical arguments that prevent this from being an issue. For instance if country 1 put up enough of these things they would be able to supply a large proportion if not all of their countries energy needs creating a significant economic advantage for country 1. Said country then decides to point one elsewhere to burn down a city or military installation in country 2 therefore breaking the International space treaty and probably many others, and the international community forces country 1 to dissasemble their SPS-alpha capability, causing them severe economic dissadvatage.
TLDR using these as weapons makes no economic sense.
In a cybernetic fit of rage she pissed off to another age...
Because solar orbit at 10% earth distance would make the magnifying glass zoom around the sun multiple times per earth year. There would be no way to get the rays from the glass to the collector. You'd be better off having the collector out there with an amiable maser.
Space-based solar doesn't make a lot of sense until we get a whole lot closed to a Kardashev Type I civilization than we actuallly are. There's simply no way that firing panels into space on a $100 million dollar rocket is more cost effective than sticking them on the ground where Bob the Electrician can install and maintenance them.
It does make sense though in some *very* limit circumstances. If you frequently work in areas that have no power infrastructure, and can afford the jaw-dropping premium of space-based power. Those two facts suggest this is the public face of some kind of military or intelligence project.
The only orbits that have no period when the sun is blocked by Earth's shadow ("night") are polar (remember the pictures of sunrise over the Earth shot from space by various astro/cosmonauts?). No single ground station could receive the power.
Also, there would be considerable photon pressure pushing the satellite(s) away from the Sun and, hence, Earth, plus gravitational drag attempting to pull the orbits around he Earth. Not a big deal for a short-term recon satellite, but these would be intended to there for years. Any of the rocket scientists out there know if the polar orbits are even vaguely stable, or will the satellite need boatloads of fuel to stay where it's needed. Of course, the beam of Earthbound power is a thruster, too, raising the orbit.
Put the collector at the Eath-Sol L1 and you've got to have REALLY good beam control to keep from raising the temperature of the entire Earth.
Sounds more like weapon than a power source to me.
The problem is: How do you prove that it was an intentional event, as opposed to a malfunctioning of the controls?
Or what if one country hacks into another country's control system and uses one of their satellites as weapon? If the satellite happens to be on the other hemisphere (so there's no danger of accidentally hitting the own country), they don't even need to have control. Just DoS the other country's control, and have the out-of-control satellite burn populated areas at random.
Something like a system whereby the satellite will only transmit when it is within a fraction of a degree of its normal orientation, or a signal constantly transmitted by the base station when it is receiving, a combination of both. That's just off the top of my head while I'm at a party I'm sure the researchers involved have thought about this a lot.
In a cybernetic fit of rage she pissed off to another age...
JAXA (Japan Aerospace Exploration Agency) has been working on such a system from a number of years and plans to have 1-gigawatt space solar power system operating around 2030. http://www.jaxa.jp/article/interview/vol53/index_e.html
The obvious question is if the beams can be focused, and used as a weapon, it could provide a no-warning and very destructive attack anywhere in the world. It seems to be what Mankins is trying to avoid, and I tend to agree that (aside from cost) we really, really need to make sure that the power sources of the future are not just being used to cloak the real objective: Making powerful weapons.
Let me help you with that. The answer to your obvious question is "yes". Hence the problem...
Of course there are dozens of ways to use a high orbital position to control the Earth. Nuclear armed satellites. Project Thor. A nice collection of medium sized asteroids movable/targetable by means of e.g. Orion (small nukes used to push them, solar powered ion jets or solar sails for finer control).
I worked through the physics of this out of sheer curiosity a few years ago, and no, it really won't ever really be "safe", nor will it ever be cost effective. It is, in fact, a really stupid idea as far as I can tell. Solar cells are cheap and plentiful right here on the Earth, and are getting cheaper all the time. If you take a square kilometer of the Earth's surface, you have order of million square meters of collector (times cosine theta). On a cloud free day, you have anywhere from 700 to 900 watts/m^2 hitting the collector panels (peak a bit higher, these are sort-of-averages). Depending on the kind of panel, you get (say) 10% conversion (cheaper panels get less, more expensive ones get more). Call it 90 watts per square meter. Your one kilometer square area thus yields ballpark of 90 megawatts -- but let's say only 50 (and of course, only during the daytime). 20 square kilometers is thus a gigawatt plant, which is quite respectable -- an area some (say) 5 km squared, allowing for roads and access and the need to be able to tip them through at least some angle to maintain a small angle of incidence as the sun moves overhead. The cost per watt of the panels is order of $1 (probably less, at this scale). The cost of the land is whatever we want it to be, if we use public lands or inexpensive fallow lands that cannot be used for much else (abundant in the southwest, less so in the more developed midwest and east). Let's presume that the additional cost of the land, the electronics, and at least a modest storage array to buffer small fluctuations in power delivery is another $1/watt. You end up with a 1 GW plant for 2 billion dollars, which is actually not particularly crazy even now in places where electricity costs a lot (which is why private citizens are doing it). In reality, I think it would end up costing maybe half of this by the time economies of scale kicked in, which would give you an amortization time of less than a decade on the initial capital investment and at least a decade of pure profit. Not the fastest way to make money, but not a money loser and in a market dominated by low interest rates a not unreasonable ROI.
Now take the same solar panels -- the EXACT same solar panels, mind you -- into orbit. A couple of useful (approximate) numbers. It costs 64 megajoules to give 1 kg escape velocity (1/2 times 1 kg times (11.2 \times 10^6)^2). An orbit costs anywhere from 1/2 of this to the full amount, depending on the orbit. A geosynchronous orbit would actually cost most of it at 5 R_e -- call it 50 megajoules per kilogram. Of course, this is the pure energy cost at perfect efficiency. In fact, the cost in US dollars per kilogram in GEO is order of $10,000!
Assuming -- not unreasonably -- that the solar panels we lift into orbit mass out at a 100 grams per square meter, and are absolutely egregious in assuming that they get ten times the power per square meter compared to collectors on the Earth's surface (2-3 from higher insolation, the rest from extending "daylight" hours by a factor of almost three, still leaves us short but with round numbers) we can, indeed, get our (earth surface equivalent) orbiting GW at an equivalent cost factor of roughly 100. That m
Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
Modern nuclear plants have failsafe after failsafe. The control rods are held out of the core electromagnetically, so if the control system loses power they'll all drop instantly an initiate SCRAM.
The reactor can still be dangerous afterwards, though - the unstable isotopes produced as a byprodct of fission continue to delay. That's what happened at Fukushima - the SCRAM worked perfectly, rods dropped the moment the earthquake hit, but the earthquake and tsunami managed to destroy not only the cooling system backup generators, but also the switchgear that connecte up the backup backup generators and the backup backup backup 'We're really screwed now' emergency external power interface for connecting portable generators or feeding power back from the grid. There was a design flaw in there - although there were four seperate means of powering the cooling system and full redundency in the switching, both that switching and the redundant backup were located in the main turbine hall, a room that the tsunami flooded.
Despite all that panic though, Fukushima has a total of *zero* deaths as a result of any nuclear accident, and contamination of the surrounding land is minimal. The ocean took a lot of radiation, but all short-lived isotopes.
Last time I did something similar in Simcity, my city got attacked by aliens...
I've got better things to do tonight than die.
This is way off topic, but I'll bite anyway.
The text of the second amendment is thus:
A well regulated militia being necessary to the security of a free state, the right of the people to keep and bear arms shall not be infringed.
The first clause is an explanation for the second, and the amendment clearly places a limit on the power of the federal government (later amendments and rulings mean that this also affects the states). And that limit is that congress does not have the power to infringe the right of the people to own and carry weapons.
It does not say what kind of weapons. It does not grant congress a "reasonableness" pass, to allow them to regulate particularly dangerous or unpopular weapons. A modern reading could imply that the explanatory clause could be used to imply that congress may be able to pass some kind of perfunctory regulation, as long as that regulation does not infringe on the people's ability to keep and bear those arms. Perhaps through a mandatory firearm safety course or basic military training course for all citizens.
However, even that much doesn't really fly in the face of the ninth and tenth amendments. Especially the tenth.
What many of the "reasonable gun control" people (and certainly not all by a long shot) seem to fail to recognize is that while reasonable gun control may be desirable, especially in light of the far more destructive and portable weapons available today compared to the founders' day, the price doing it without having a constitutional amendment specifically enabling congress to act is the watering down of the constitution as a compact with the people.
What else can we conveniently interpret away or ignore that allows congress more power, and more importantly strips power away from the ostensibly consenting governed?
If you want gun control to quell your fears, it's certainly not an unreasonable goal, but the safest way to seek it is not to demand immediate action in immediate aftermath of each tragedy, but to demand the thoughtful debate of the constitutional amendment process. Then we can decide as a nation what level of risk we're really willing to live with, balanced against what powers we really want to allow the government to have.
Can you be Even More Awesome?!
If SimCity has taught me anything, it's that it's cost-effective and, indeed, safest to bulldoze and rebuild power-plants every 49 years, exactly.
Can you be Even More Awesome?!
Lets think about that.
The solar constant is about 1.36 kW/m^2. One quarter sun would be about 0.34 kW/m^2.
My microwave magnetron output is 0.75 kW. Spread out on a sphere of 2.2 m^2, this is 0.34 kW/m^2.
The area of a sphere is 4*PI*r^2, so r = 0.42 m
I was wrong. Its like standing in front of a microwave with its door open a little less than half a meter away. I was being conservative in my previous post.
Have gnu, will travel.