[KaiserJeep]

Of course, this is also about the dozenth time I have seen a bit of SF technology abstracted out of a classic novel ...

Where does your "scooping gasses from gas giant planets" technology come from?

That's hard science. It was in Wired magazine. Or was it Omni?

It was actually proposed by NASA. That is an easy way to acquire hydrgen and helium. Some of the moons of the giant planets have other gases such as Methane, They also noted that the rings of Saturn are largely water ice.

Solid materials including various stones and metal ores can be found in the asteroids. Space contains effectively unlimited materials and energy. All of these places and processes are possible with current technology, no fundamental advances required.

[Keith_McClary]

Of course, this is also about the dozenth time I have seen a bit of SF technology abstracted out of a classic novel ...

Where does your "scooping gasses from gas giant planets" technology come from?

That's hard science. It was in Wired magazine. Or was it Omni?

Or Amazing, perhaps?

The only serious-ish discussion I can google is:

Scooping Atmosphere

It is often suggested that atmosphere could be collected in bulk by a scoop-craft dipping from and returning from low orbit. This is not as easy as it seems at first sight.

The mass of a scoop-craft does not matter while it is steadily scooping; only when it is changing velocity non-gravitationally. For a reasonable collection rate, a large drive would be needed to maintain speed; it must accelerate everything collected, and overcome aerodynamic drag.

To scoop, one really needs a ramjet.

In scoop-craft coordinates, a fraction X of all that is scooped is decelerated from orbital speed to zero and, for conservation of momentum relative to the scoop-craft, the remaining fraction (1-X) must be accelerated from orbital speed to (orbital speed × X/(1-X)).

The energy needs to be provided by a source carried on the scoop-craft (unless atmosphere can be fused); and a supply of chemical fuel will not suffice to collect more than a lesser amount (as orbital speed exceeds chemical exhaust velocity). It must use on-board nuclear, or solar, or beamed, power.

The kinetic energy, with respect to the scoop-craft, of the fraction collected must very largely go into the exhaust, whether as mere heat or in a better-organised manner - otherwise, the collector will rapidly melt.

If the heat question is solved, a craft arriving from infinity might aero-capture without using power, and simultaneously acquire reaction mass for use later, say in orbit circularisation.
http://www.merlyn.demon.co.uk/astron-2.htm#Scoop

[Tanada]

Of course, this is also about the dozenth time I have seen a bit of SF technology abstracted out of a classic novel ...

Where does your "scooping gasses from gas giant planets" technology come from?

That's hard science. It was in Wired magazine. Or was it Omni?

Or Amazing, perhaps?

The only serious-ish discussion I can google is:

Scooping Atmosphere

It is often suggested that atmosphere could be collected in bulk by a scoop-craft dipping from and returning from low orbit. This is not as easy as it seems at first sight.

The mass of a scoop-craft does not matter while it is steadily scooping; only when it is changing velocity non-gravitationally. For a reasonable collection rate, a large drive would be needed to maintain speed; it must accelerate everything collected, and overcome aerodynamic drag.

To scoop, one really needs a ramjet.

In scoop-craft coordinates, a fraction X of all that is scooped is decelerated from orbital speed to zero and, for conservation of momentum relative to the scoop-craft, the remaining fraction (1-X) must be accelerated from orbital speed to (orbital speed × X/(1-X)).

The energy needs to be provided by a source carried on the scoop-craft (unless atmosphere can be fused); and a supply of chemical fuel will not suffice to collect more than a lesser amount (as orbital speed exceeds chemical exhaust velocity). It must use on-board nuclear, or solar, or beamed, power.

The kinetic energy, with respect to the scoop-craft, of the fraction collected must very largely go into the exhaust, whether as mere heat or in a better-organised manner - otherwise, the collector will rapidly melt.

If the heat question is solved, a craft arriving from infinity might aero-capture without using power, and simultaneously acquire reaction mass for use later, say in orbit circularisation.
http://www.merlyn.demon.co.uk/astron-2.htm#Scoop

Try this one http://news.discovery.com/space/project ... 110531.htm

[Scrub Puller]

Yair . . .

This is not as easy as it seems at first sight

Really?

Cheers.

[KaiserJeep]

My point was, we have already thought through and anticipated such problems with scoop ships, and proposed solutions.

Getting copper from 0.2% ores at the bottom of a 3/4-mile-deep hole in the ground is anything but easy. It is not clear to me whether mining copper from asteroids has a greater or lesser energy cost than mining on the Earth in such open pits, or in the Earth the mile deep shafts of the South American copper mines.

Whether the energy cost is greater or lesser, what is certain is that in space, energy is cheap and unlimited, whereas on Earth it is increasingly expensive and getting rarer all the time. Whenever the economic crossover to space operations comes about, we will be ready. Even such online discussions as this are helpful, as space skeptics are being exposed to new ideas - the next time the topic comes up, the idea will not have to be spoon fed to your heads, you will already know what we are talking about.

[Tanada]

My point was, we have already thought through and anticipated such problems with scoop ships, and proposed solutions.

Getting copper from 0.2% ores at the bottom of a 3/4-mile-deep hole in the ground is anything but easy. It is not clear to me whether mining copper from asteroids has a greater or lesser energy cost than mining on the Earth in such open pits, or in the Earth the mile deep shafts of the South American copper mines.

Whether the energy cost is greater or lesser, what is certain is that in space, energy is cheap and unlimited, whereas on Earth it is increasingly expensive and getting rarer all the time. Whenever the economic crossover to space operations comes about, we will be ready. Even such online discussions as this are helpful, as space skeptics are being exposed to new ideas - the next time the topic comes up, the idea will not have to be spoon fed to your heads, you will already know what we are talking about.

In Situ extraction does wonders, several Uranium projects in the USA are doing it that way now. You drill a well into the formation, frack it, force corrosive liquid into the fractures to dissolve the metals you want, then pump them back up to the surface for separation and reuse of the chemical.

[basil_hayden]

This brilliant scientist/venture capitalist is using the same fundamental knowledge of engineering organisms to do a variety of things - make liquid fuel, create edible proteins... It's true 21st century industrial revolution.

The guy is solving some major world-class problems.

Joule Unlimited, LENR - these have been two of my favorite posting subjects. But there has been a long lull in news from either of them. It`s funny that news is breaking on both of these subjects once again.

But what is so stunning is that these technologies - engineered organisms used to produce fuels, foods, etc. and the harnessing and widespread use of the Pons-Fleischman effect (LENR) - apparently these technologies are definitely on the way in the very near future.

Not one damned thing has been solved! Some symptoms may be temporarily addressed. Still 7 billion people here using up resources faster than the planet can replace them. News is breaking on these subjects once again because Christmas has passed and the IRS tax refund checks will be coming in soon - time to hook the next "investors".

[Quinny]

Do I detect a hint of desparation here? Is this the drivel that the KR bargaining stage drives people to. Atmospheric scoops ROFL!

[Keith_McClary]

Do I detect a hint of desparation here? Is this the drivel that the KR bargaining stage drives people to. Atmospheric scoops ROFL!

Hey, anything's possible!

Accessing the gas riches of Uranus will require nuclear power, however. Designs exist for nuclear powered ramjets that could fly indefinitely in the atmospheres of the gas giants -- this might prove a viable means of keeping an extraction factory aloft. Else we'll be back to using balloons like "Project Daedalus," serviced by nuclear ramjets.
...
A starprobe might launch by the year 2100 and if world energy demands continue to increase at their historic rate of 2.5 percent, then by 2100 about 14,000 tons of deuterium/helium-3 fuel-mix would supply the world's energy demand per year, adding an incentive to develop the gas-mines of Uranus.
http://news.discovery.com/space/project ... 110531.htm

What happens if world energy production doesn't continue to increase at it's historic rate of 2.5 percent until 2100. Will "we" be have the EI part of EROEI to do this?

[eclipse]

For me the interesting aspect is that all these we-save-the-world projects depend on photosynthesis, therefore, a rough estimate of efficiency and maximum potential should use the efficiency of photosynthesis as reference.

BTW: Hartmut Michel, the guy who won the Noble price for his work on the structure and function of the photosynthetic reaction centre calls in the editorial of very good journals these approaches in principle nonsense because of the low efficienc (esp. compared to available PV) of the photsynthesis. For me all this is a simply selling of snake oil (seach for dumb money) as long as no hard data are delivered.

No, *all* these 'save the world' schemes do NOT rely on photosynthesis! James Hansen would disagree! His Science Council for Global Initiatives promotes nuclear waste-eating GenIV reactors like the IFR, and for transport? Boron. Problem solved.
http://eclipsenow.wordpress.com/2014/01 ... e-deniers/

[Quinny]

Nukes a bit off topic here, and I think you are being pedantic to call Ull on it, but as you raised them.

I was firmly anti-nuclear, on environmental and economic grounds, but also because of the links with weapons production. I demonstrated with CND throughout my younger years, and still believe there are inherent dangers in the technology. Desperation however makes one clutch at straws for ones kids and I would be willing to consider some kind of Nuclear future to keep the lights on if a solid argument could be put forward.

It doesn't however IMHO negate the need for Powerdown and a total change in the system. If we continue to rape the earth the way we are doing life will get tougher and environmental degradation will make the earth a very difficult place to live.

I also doubt the scale-ability of the 'burn the waste' technology. It doesn't solve our liquid fuel problem either.

For me the interesting aspect is that all these we-save-the-world projects depend on photosynthesis, therefore, a rough estimate of efficiency and maximum potential should use the efficiency of photosynthesis as reference.

BTW: Hartmut Michel, the guy who won the Noble price for his work on the structure and function of the photosynthetic reaction centre calls in the editorial of very good journals these approaches in principle nonsense because of the low efficienc (esp. compared to available PV) of the photsynthesis. For me all this is a simply selling of snake oil (seach for dumb money) as long as no hard data are delivered.

No, *all* these 'save the world' schemes do NOT rely on photosynthesis! James Hansen would disagree! His Science Council for Global Initiatives promotes nuclear waste-eating GenIV reactors like the IFR, and for transport? Boron. Problem solved.
http://eclipsenow.wordpress.com/2014/01 ... e-deniers/

[Ulenspiegel]

@eclipse

The headline of the topic was "Cellular based pricise...."

In this biological context I made my (correct) statement.

If you like nukes that is no problem for me. However, here the strategy ususally is to use the fact, that the energetical problem is solved, to whitewash severe technological problems and aspects stupid economy.