This Satellite Could Be Beaming Solar Power Down From Space By 2025 245
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."
Re:Nope. (Score:5, Insightful)
Agree with the poster. I figure solar cells in space will not trump solar cells on the ground until we dramatically lower the cost of delivery to orbit. At the moment we SpaceX is quoting 4300 USD/Kg to orbit on a Falcon 9 (1.1 - still waiting on maiden flight Sept5), and maybe down to 1200 UDS/Kg for the not yet built or demonstrated Falcon Heavy. And that is to LEO, Solar Cells probably need GTO which is about twice as expensive. I can't imagine a space based array can be competitive at those prices.
Now if someone built a rail-gun based launcher, then maybe it could make sense.
And as AC mentioned, we are in the midst of a ground based solar cell revolution right now. Very cool...
Re:Nope. (Score:1, Insightful)
Editors are different, but a (compared to other fora) disproportionately large amount of Slashdot commenters seem to subscribe to irrational right-wing denialism of gun violence, anthropogenic climate change and the effects of Fukushima. Maybe related to being rich US men in tech jobs?
Re:It's all good until (Score:4, Insightful)
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.
Re:My god, what has science wrought??? (Score:5, Insightful)
I'm curious - how much taxpayer funding has this received?
Less than a day's worth of military funding, I'm sure. And this is not an expenditure, it's an investment.
Re:Nope. (Score:4, Insightful)
Although it may not be economical, there are significant advantages in space vs ground. Average daily insolation is at least 4X better. Because putting the space panels in place is so expensive, the fractional increase in cost of using high-tech panels is smaller: a 60% power/area (power/mass) improvement over single-crystal silicon.
As long as the solar pressure on the installation is less than the Earth's gravitational pull, it should be possible to design an orbit that will keep it in place. After all, when the installation is nearer to the sun than the Earth, the sun's radiation is pushinf it toward the Earth.
Re:My god, what has science wrought??? (Score:5, Insightful)
I can't help but notice that you're comparing with social programs, and the DoD, which is grossly overfunded, is thrown in as an after thought. Goes to show why the US is in such trouble. Wellfare programs are essential, but get relatively little money. But, the DoD, gets a crap load of money, with little or no benefit for the funds.
What's more, a huge number of the people on welfare are there because we signed all those free trade agreements and shipped the decent paying jobs overseas. All while making it harder and harder for employees to organize, and slashing taxes that the rich pay.
Re:It's all good until (Score:4, Insightful)
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.
Re:Nope. (Score:5, Insightful)
I think, and I'm not as smart as I once was, so this an opinion, not a statement of fact, that a geosynchronous satellite would be eclipsed by the Earth for a significant percentage of the time. There's probably an orbit that maximizes energy collection, but I don't have the slightest idea what it looks like.
Not all that significant. Remember that the Earth's equator is inclined about 23 degrees relative to the plane of the ecliptic. Because of this tilt, combined with the distance the satelleite is from the Earth, a solar power satellite will experience *no* eclipses from the Earth for about two thirds of the year, and some period of eclipse during the remaining third. But even at the worst point in the cycle, the eclipse period is only about 70 minutes per day.
Net result is that a good old geosynchronous orbit is good enough for a solar power satellite (and greatly reduces the headaches of keeping the power beam targeted at the receiver).