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#51 Re: Science, Technology, and Astronomy » A renaissance for space solar power? » 2007-08-20 12:43:38

I this puts the economics somewhat in perspective:

"First, 5MW is the power on orbit. Jay Penn has suggested that there 30% efficiency is achievable for end-to-end transmission efficiency. That is 1.5MW continuous on the ground.

Next, there are 8760 hours per year. If you assume 98% uptime (2% in shadows), that is 8585 hours of power delivered at 1.5 MW.

or 12.877 MILLION kwh delivered per year.

at $15 per kwh that is $189 Million revenue per year.

at $80 per kwh that is $1 Billion in revenue per year.

I am assuming that the DOD likes the lower end of the spectrum much more.

For just one operational 5 MW power system. If the service provider starts building these systems in series, pretty soon we are talking about real money.

The next issue is how much it will cost to build these systems in orbit. We still need to do that work.

Personally, I believe we are in the neighborhood of closing the business case. If the DOD is willing to pay $1B per year, the case probably closes using existing LVs. Assuming the DOD wants to pay on the lower end of the spectrum, we probably need much lower cost launch (reusable spaceplanes). A national investment in spaceplanes will deliver one more benefit to our nation. Other recommended policies that would lower the cost per kwh to the DOD are investment tax credits (for companies investing in this high risk industry), tax holidays (Zero G, Zero Tax), and access to low cost debt (in the form loan guarantees on the demand side, after the technology has been proven.)"
http://spacesolarpower.wordpress.com/20 … iscussion/

#52 Re: Science, Technology, and Astronomy » A renaissance for space solar power? » 2007-08-20 12:34:08

I wonder how small a collector they can use and how easy it will be to set up?

~10 km^2 with microwave.  Hmmm, guess they'd better go with laser.

Will the space beam give away their military position?

Depends on how sophisticated the opponent is.  Good thought though.

BTW, they're discussing it publicly here ...

http://spacesolarpower.wordpress.com/

I found this interesting:

"In the general soup of contemporary alternate energy discussions, diode laser beamers in geostationary orbit are a total game-changer for demonstrating space based solar power experimentally. We can build and test them now. Can we beam electricity into Iraq even as the insurgency blows up power lines? Can’t say now how much it might cost, but it’s certainly feasible in principle. My predilections are to demonstrate beaming power to some poor African village, winning the hearts and minds of our brothers and sisters in the developing world, as opposed to blasting them to bits, as some will certainly accuse developers of laser power beaming of. But the thing about any new technology is that you really can’t say at the outset where exactly it will go. What we can say with some assurance that no one has a clue how to build a small, cheap fusion reactor that would work. But we can almost certainly build an SSP with laser beaming now that would work; and build it small enough to fit into a single launch vehicle payload at a small fraction of the cost of ITER, or for that matter of FutureGen (DoE’s proposed coal-gasification to electricity and hydrogen pilot plant with CO2 sequestered), or one of DoE’s new design Gen IV fission reactors on the drawing boards. So I want to strongly agree with Jordin Kare’s comments on a the viability of an laser SSP demo expressed in his E-Mail below."
http://spacesolarpower.wordpress.com/20 … e/#more-54

I wonder, some new cities in India have trouble meting power demands. If a business could set up a receiver on the roof they would be assured reliable power (atleast for sunny days)

#53 Re: Science, Technology, and Astronomy » A renaissance for space solar power? » 2007-08-20 08:24:10

It sounds pretty cool. You know what the conspiracy theorists  are going to say. They'll say the soldiers are getting sick because the government is beaming space radiation down on them.  roll I wonder how small a collector they can use and how easy it will be to set up? Will the space beam give away their military position?

#54 Re: Science, Technology, and Astronomy » Fusion » 2007-08-18 15:20:30

It's good news, however most plans include basically waiting on the ITER results - but those aren't due until 2025.  Maybe one of the IEC Fusion ideas will work out.

Why do the results take so long?

#55 Re: Interplanetary transportation » Falcon 1 & Falcon 9 » 2007-08-18 14:57:39

Monster Progress Update (Mostly Falcon 9)
http://spacex.com/updates.php

Too much to quote here.

Is it wise for them to change the engine before they demonstrated a successful flight. It seems they are pretty confident that the falcon 1 is going to work and are now focusing on the falcon 9. I hope they are right.

#56 Re: Science, Technology, and Astronomy » Fusion » 2007-08-17 18:09:28

Russian scientist calls for fusion research program by year's end
http://en.rian.ru/russia/20070816/71818954.html

A leading Russian nuclear scientist said the country must adopt a federal targeted program on the research and potential use of fusion power as an alternative energy source by the end of 2007.

A government meeting adopted Thursday the main provisions of a draft strategy for developing a fusion power industry up to 2015 and beyond, and instructed the Federal Agency for Nuclear Power to prepare a revised version of the document by October 1.

The strategy stipulates the allocation of 515 billion rubles (about $20 billion) for the development of a fusion power industry, including construction of commercial thermonuclear reactors, until 2050.
...

Okay, this is good. Now we must convince our governments that they need to beat the Russians.

#57 Re: Science, Technology, and Astronomy » That's Not a Comet, that's a Star » 2007-08-16 09:19:06

http://www.universetoday.com/2007/08/15 … ts-a-star/

Mira is an older, red giant star shedding massive amounts of material into space. As the star moves quickly through interstellar space, the particles slow down, and remain as a long tail stretching behind. In fact, this tail is 13 light-years long, or 20,000 times the average distance of Pluto from the Sun.

...

[ Pretty picture ... ]

http://www.jpl.nasa.gov/images/galex/20 … browse.jpg

Wow! That's amazing.

#58 Re: Interplanetary transportation » Followup on the Heim Drive » 2007-08-14 13:11:31

If the Tajmar result is true - that we can generate gravitational fields from EM fields at the level he describes - then all the rest follows.

But we can't  sad

Tajmar rules out his own result in his latest paper ...

Search for Frame-Dragging in the Vicinity of Spinning Superconductors
http://arxiv.org/pdf/0707.3806

He finds something else, but it is hyperweird ( signal when rotating clockwise but not counter-clockwise - WTF? ).

Blah.

One day we will have the answer.

#59 Re: Not So Free Chat » Alternative Space ventures - are we on the road to cheaper access » 2007-07-29 20:48:39

It sounds interesting but why not just have them pre deployed near the destination.

<cigar chompin'>'cause today's targets ain't destinations, they're networks.  And the nodes are mobile.

2 hours to combat.  Anywhere on Earth.  Almost makes you feel sorry for da bad guys.  Almost.</cigar chompin'>

Also how big a crew could the suborbital transport fleet carry?

<gamer>Just two.  But that's all they'll need, 'cause they'll be wearing powered armor and carrying man-portable rail guns.  Game over dude.  Game freakin' over.</gamer>  (Actually, I think it is 6-8).

I’m sure it would be expensive so I wouldn’t expect a lot of vehicles.

These are guys who fired 400 missiles costing $2 million a piece to quote shock and awe unquote.  And suborbitals are way cheaper if you're only going to use them once.


Okay, you have me sold. Who is working on the power armor?

#60 Re: Not So Free Chat » Alternative Space ventures - are we on the road to cheaper access » 2007-07-29 19:32:04

That is kind of interesting. Isn’t Northrop Grumman Corp. a pretty big company?

Yes it's puzzling, isn't it.  I wonder what they'd use a suborbital transport for?

http://en.wikipedia.org/wiki/SUSTAIN_%28military%29

It sounds interesting but why not just have them pre deployed near the destination. Also how big a crew could the suborbital transport fleet carry? I’m sure it would be expensive so I wouldn’t expect a lot of vehicles.

#61 Re: Interplanetary transportation » WARP DRIVE, AHEM! » 2007-07-29 18:04:37

No.

Gravity is a fundamental property of matter, and (aside from a few very small relativistic effects) has nothing to do with rotating objects.  Einstein's theories hold everywhere, not just in atmospheres.  Gravity exists everywhere.  And physical laws are no different in space than they are here on Earth.

You're right that mass is a fundamental property measured in kilograms, it "increases" when traveling at relativistic speeds, density is mass/volume, and w=mg gives a good approximation of gravity at sea level, which is measured in newtons.  There's no kind way to say this, so I'm being blunt: Everything else in your post is nonsense.  Go read a book or something on physics.  I recommend the MIT video lectures.


Electromagnetism is a fundamental property of charge but for some reason we can do a few more things with it then static cling.

#62 Re: Not So Free Chat » Alternative Space ventures - are we on the road to cheaper access » 2007-07-29 17:59:31

That is kind of interesting. Isn’t Northrop Grumman Corp. a pretty big company? They must have saw some value in the company, “Scaled Composites”.

#63 Re: Not So Free Chat » Need a Wiki » 2007-07-29 17:07:05

Yep, it's still there ...

http://newmars.com/wiki/

Oh, okay they seemed to remove the link from the main page.

edit: it seems to have expanded since I last checked.

#64 Re: Not So Free Chat » Need a Wiki » 2007-07-29 16:25:40

what happened didn't we have a wiki?

#65 Re: Other space advocacy organizations » NASA clarifies the role of other advocacy organizations » 2007-07-29 14:28:36

I don't think Griffin is saying advocacy groups shouldn't exist, I think he is just saying that they need to understand how NASA needs to balance priorities. The more groups that show an interest in space exploration the more pressure there will be on congress to obtain the necessary funding.

#66 Re: Human missions » Earths Oceans Explored - but why not colonized » 2007-07-29 13:15:24

Yes and sometimes those little islands are in the wake of such things as huricanes, cyclones and just down right nasty weather...

As are oil rigs, existing islands, ... and well, just about every piece of coastal land.  Surface weather is hardly a show-stopper.

Because the resources are underwater.

Which resources?

Fish, animals, and plants grow better on the surface than they do in deep water.  The nutrients may be at the bottom, but that water can easily be pumped up.

Mineral, methane, and oil resources need some humans on the bottom of course, but the oil industry has shown that it's more economical to separate resource acquisition (which requires just a few people on the bottom) from processing and use which can be done more cheaply on the surface.

I'm not sure if oil rigs are really floating cities. Aren't they anchored to the ground. Considering the amount of material required to build an oil rig, I'm not sure it is the engineering model we want to look at at overcoming the harsh ocean enviornment.

If everyone lives at the surface I'm concerned that they will block a lot of the light that my be required for the lower eco system. Also it just doesn't appeal to my imagination as much as an underwater city.

#67 Re: Human missions » Earths Oceans Explored - but why not colonized » 2007-07-29 13:11:55

I don't think colonizing the ocean, despite its vast space, would be particularly wise.

It is the biggest, most interconnected, and least-studied enviorment on the planet.  Consider where we live now, on continients and even cities on the fringes of desserts can contribute runoff that already off-balances lord knows what in terra aqua.

...and you're talking about floating cities of a few thousand easy directly out there?  Think of the phrase "poop deck" and conceptulaize how the sewer system would work.  Then add in oil leakage, garbage, paper wrappers wafting in the breeze and six-pack-rings floating toward breeding grounds of otters and endangered sea birds.  The urge to dump all our waste into something seemingly vast would be too easy and powerful for an ocean city.  Within fifty years given a few dozen floating New New Yorks and New Londons you'll have the Ocean Thames reaking of dead fish.

Don't count on harvesting the Ocean either - it is NOT as fruitful as people think.  Areas the size of the United States are already being swept to the ocean bedrock every year; the ocean's equivellant of the Amazon's hack-and-slash burnings.

May as well suggest Antarctica - fresh penguin eggs and meat waiting to turn giant colonies of those cute lil butlers into colonies of the next dodo bird. (cue the screams of a thousand 'March of the Penguin' and 'Happy Feet' fans imaging penguins getting clubbed like baby seals). And with the ice thawing and sun half the year oooh...sun worshippers and resorts.

They would need to recycle their wast and have anti-littering laws as harsh as Singapore's.

#68 Re: Human missions » Earths Oceans Explored - but why not colonized » 2007-07-28 14:04:27

Why build underwater and deal with the issues of pressure, light, transportation, leaks, etc. when you could live on the surface (artificial islands)?

Just a thought.

Because the resources are underwater.

#69 Re: Terraformation » Floating Venusian cities or Venus vs Mars vs Titan revisited » 2007-05-23 00:46:45

A 2 bar Venus will boil water at around 104c, so its a further 4c margin to a runaway steam problem.

How is there going to be a run away steam problem if there are no oceans.

#70 Re: Human missions » Jeff Bell » 2007-05-05 13:01:50

The Griffin Space Fantasy

NASA boss Mike Griffin says we can do three Apollo-scale projects over the next 50 years without increasing the NASA budget. It sounds too good to be true - and it is. Griffin's analysis of NASA's past relies on questionable economics and his vision of the future includes political and technical impossibilities.

Mr Bell has unfortunatly got a chance to have a good bite into what is rapidly becoming clear that NASA just does not have the money to actually accomplish what it has promised.

The March 14 2007 issue of Aviation Week contained an article by NASA Administrator Mike Griffin which apparently is the most detailed statement yet of his long-range plans. In this article and related press interviews, Griffin makes a case that NASA is not really as underfunded as many critics say, and that the US can afford three major space projects on the scale of Project Apollo over the next 50 years without major budget increases.
Specifically, he argues that a steady budget of about 14 billion FY2000 dollars per year can comfortably accommodate the Moon landing, Moon base, and Mars landing programs proposed by President Bush in February 2004.

There has been surprisingly little discussion of this key article. Possibly many space advocates suspect that the news is too good to be true. After all, on March 16, Griffin appeared in person on Capitol Hill to argue for a major increase in NASA funding of exactly the kind he had claimed was unnecessary in this article. This contradiction should have tipped us all off that the AvWeek article is not a serious analysis.

He then goes into a cost analysis and details of inflation compared to needed rises in NASA's budget.

A bigger question is: why do so many space cadets still worship Griffin and believe everything he says, without the normal level of skepticism directed at the statements and actions of political appointees? The answer is that Griffin is a master at divining what we want to hear and telling us exactly that. We are so accustomed to seeing bland organization men at the helm of NASA that we have been blinded by the sheer novelty of an Administrator who shares our romantic vision of space. We need to open our eyes and demand some hard-nosed rational planning to back up that vision.

ouch

Isn't the money there? Isn't the only question: how quickly can the new hardware be delivered?

#71 Re: Terraformation » Floating Venusian cities or Venus vs Mars vs Titan revisited » 2007-04-17 22:40:33

With Venus's thicker atmosphere and slightly lower gravity then earth, scram jets and ram jets will work at higher altitudes then on earth.

Unfortunately Venus' atmosphere is oxygen-poor, so being airbreathing wouldn't give you much of an advantage.  Maybe some other type of low cost to low orbit infrastructure though - perhaps airship to orbit or aerovator.

Good point. I wonder how well airship to orbit would work on Venus. I've never heard of aerovator before though.

#72 Re: Not So Free Chat » horror of another school shooting » 2007-04-17 22:36:50

Tom you sound like a complete lunatic. Their is no reason for this massacre. The guy was just crazy. You can't blame culture because he lived in his own world. You can't blame guns or lack of guns, and your anti-American theory is so far off in the deep end it is not even funny. Here is a clue, the guy had an imaginary girlfriend. If you want to find out the reason you would have to know what some of the voices in his head were saying. Remember he lived in his own world and who knows what role these people that he shot played in his imaginary universe.

#73 Re: Terraformation » Floating Venusian cities or Venus vs Mars vs Titan revisited » 2007-04-17 09:09:48

If Venus is forced to compete with Mars by launching big dumb boosters from the cloud tops then it is going to have a hard time overcoming the delta-v penalty.

With Venus's thicker atmosphere and slightly lower gravity then earth, scram jets and ram jets will work at higher altitudes then on earth. I am not sure if that give Venus any edge over mars though since Mars requires less Delta V to launch from then Venus.

#74 Re: Terraformation » Floating Venusian cities or Venus vs Mars vs Titan revisited » 2007-04-09 17:31:48

Just picturing the first balloon being setup in the Venus atmosphere so work can progress to build the city.

I can't see a willing soul brave enough to be on it until it's a pretty big and safe structure.
You will also need emergency escape vehicles for every colonist just incase of a disaster.(A few Saturn 1B earth to moon sized vehicles)

Might be an idea to include some means of a pretty close to fully machine built  floating city before anyone arrives to it.
That might be the un raveling of the idea as i think it would be a difficult project even on Earth.

I always imaged one big building or ship dropped into the atmosphere as the first node of the city. From that I pictured cantilever trusses extended to where the next building would be quilt. I pictured some giant balloon extending up from the platform where the next building would be built.

#75 Re: Terraformation » Floating Venusian cities or Venus vs Mars vs Titan revisited » 2007-04-09 17:28:57

How far would these things sink anyway? The atmosphere on Venus is 90 times the density of the earth. I can’t see these ships getting blown to the ground.

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