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For SpaceNut re #126 and #127
Thanks for bringing this topic back to life, and for then providing the encouraging news about perovskite solar cells.
I ** like ** the idea that a disorderly system can be more productive than an orderly one. The concept seems ** really ** appropriate at this time in American history.
(th)
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Volume repost for thin film glass panels
Well a 20% gets you an array of solid thin film of a panel that is with frame at least an inch in depth and you need to have 40,000 panels stacked inside a tiny volume that can only handle 2mt... which for the mass is 20 capsules to mars and by volume you need even more as a stack of the panels would be 3,333 ft tall.
The flexible thin film have efficiency sub 15 % not sure of mass or of the roll down size which they can be fitted into the capsule.
https://www.spacex.com/dragon https://en.wikipedia.org/wiki/SpaceX_Dragon
SpaceX’s Dragon capsule back on Earth with 3,400 pounds of cargo but thats with a parachute and splash down to which for mars means a trade of parachute mass and boosting the fuel to do a retro landing.while its 4 m diameter its got an internal volume of just under 9 and about 6 m tall or roughly 200 inches.
https://upload.wikimedia.org/wikipedia/ … ctions.png
shape is anything but not adaptible for the panels to fit in. of which a single from the door upward stack and maybe 2 or 3 in a layer until we are at the door hatch entrance at maybe 1.5 to 2 from the bottom. Sure a man could load from the top hatch but if we can not get them out of the normal hatch then we will have a problem with that one as well.
So 200 panels single stacked per capsule out of the 40,000 you think we need is 200 capsules and if the number is 250 or 300 then the count will drop to 160 to 135 by volume required and thats just the panels....
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repost flexible thin film panels
I think Flisom is probably the closest to what I envisage.
https://flisom.com/industries-customize … els-films/
There is no need for heavy supportive frames on Mars - there ain't gonna be no hail, no thunder and lightning, no powerful tornadoes, no earthquakes, no floods, no rainstorms, no snowstorms...
The thin PV film could be attached to v. lightweight steel supports at intervals.
SpaceNut wrote:The thin film plastic flexible while its bendible the radius seems to be quite large for a sheet panel and its a 1/4 to to 1/2 due to the wiring attachment of the panels which will need to be wired together to form the voltage output that we desire.
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If we can make the first circumference 4 meters for the 4 panel layer for maximum bend and work to the inner diameter from the outer winding them in from the hatch door would be very difficult so its got to be from the top hatch for going in and out. That makes the inner diameter about 1.5 meters with the outer diameter say 3 meters. Panel is 1 cm depth per layer winding them in a circle inside each other.
So 70 layers of 4 panels on average is 280 possibly 300 max coiled up inside the Dragon.
That makes flexible only marginally better but at a 1/3 less power....
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This is my question is that if we used the fairing or shroud for mars lander design could we do better as the shell would stay intact until its on the surface using retro rocket landing. All that would be ditched on the way down is the heatshield to all of the landing struts and engines to do there thing for a mars cargo lander.
For the ATK ultraflex panels in a capsule cargo the motor would load in first from the top and would guess that we are looking at 10 to 15 assembly pairs. The sizing of the sets are customized in wattage and size so its going to hard to figure out the exact numbers but from this we do know what can be done. Mars solar for a pair is 10kw upward on diameter sizing.
http://rascal.nianet.org/wp-content/upl … tsheet.pdf
https://www.jpl.nasa.gov/nmp/st8/tech/solar_array3.html
https://esto.nasa.gov/conferences/nstc2 … 7-0048.pdf
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This will be useful for some of the dust but not all conditions of what mars can throw at a panel on mars.
New method to remove dust on solar panels
The self-cleaning properties of the lotus leaf to shed new light on microscopic forces and mechanisms that can be optimized to remove dust from solar panels to maintain efficiency and light absorption. The new technique removed 98% of dust particles.
Particle removal increased from 41% on hydrophilic smooth Si wafers to 98% on superhydrophobic Si-based nanotextured surfaces. The researchers confirmed these results by measuring the adhesion of a micron-sized particle to the flat and nanotextured substrate using an atomic force microscope. They found that the adhesion in water is reduced by a factor of 30.
http://dx.doi.org/10.1021/acs.langmuir.9b01874
Research Report: "The Self-Cleaning Mechanism: Why Nanotexture and Hydrophobicity Matter"
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Space Based Solar Power Station
https://spacenews.com/chinas-super-heav … r-station/
China’s super heavy rocket to construct space-based solar power station
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For Mars_B4_Moon re #134
Thanks for posting the link to this impressive story!
The 150 ton launcher (hinting at reusability) is the kind of vehicle that would be needed for a project on the scale described.
It may turn out that a nation state with singular focus is what is needed to achieve something on this scale.
The ideas themselves came from a free society, but it is possible the very freedom that makes such ideas possible is a source of distraction and confusion that work against anyone hoping to actually build them.
I would be delighted to see a market based competitor appear on the scene, now that a ** real ** plan by a capable entity is on the table.
(th)
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Space Based Solar Power Station
https://spacenews.com/chinas-super-heav … r-station/
China’s super heavy rocket to construct space-based solar power station
Space based solar power provides a definite way of improving the whole system EROI of solar power. But it only applies if solar power satellites can be constructed in space using space based materials and microwave power transmission is possible without excessive losses. What gets shipped into space is mining equipment and factory units.
Solar thermal power may ultimately prove more effective than solar PV for an SPS, as concentrating mirrors can be foil thin. SPS could find its first application on Mars, as the stationary orbit point on Mars is only 20,000km above the equator and there is very little water vapour in the Martian atmosphere to attenuate a beam. When power requirements of a Martian base exceeds 1GW, an SPS may be an attractive option for expanding base power supply.
The SPS would also appear to be useful tools for any terraforming efforts. Concentrating mirrors could direct sunlight at the Martian polar regions. Extremely thin mirrors, with a mass of just 1 gram per square metre could ballasted against sunlight pressure using materials mined from the Martian moons. By directly heating high and low latitude areas of the Martian surface, water vapour will be driven into the Martian atmosphere and dissociated by ultraviolet light. This will result in a steady buildup of oxygen in the planet's atmosphere.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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For Calliban re Return on Investment by China in Geosynchronous SPS
Your arguments about return on investment seem (to me at least) to make perfect sense for a capitalist, who might be hoping to make a profit in return for taking all the risks of building a system of this magnitude.
However, Chairman Xi has NO incentive to worry about anything as mundane as that. His objective would be to accomplish a number of interrelated objectives that would place his country indisputably at the top of the competition between nation states (on one hand) and economic systems (on the other).
Chairman Xi can afford to loan himself as much of his countrymen's time as is needed to build the proposed system with ALL Earth-based inputs, in order to secure:
1) reliable power for one location, and ultimately for many locations in China
2) putting a dent into the global warming problem (admittedly after using fossil fuels to build the system)
3) technical prowess superior to most nations, and fully comparable to a few who might be in the same class
4) confirmation to the people of China (and thus to most on Earth) that the economic system is superior to all others
***
Most of your post was about SPS at Mars, which may be of interest to Chairman Xi as well.
(th)
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I have seen nothing to suggest any breakthroughs in power transmission by microwave or laser beam (and I am very keen to see the technology develop). Japan is a world leader in the technology - I think the best they've achieved is well under 1 Km and that's with significant power loss. This story is talking about sending power over 35,000 Kms!!!
Isn't this just China throwing out "chaff" to confuse the enemy? I suspect their focus is on satellite technology, lunar landing and building a Mars base.
Space Based Solar Power Station
https://spacenews.com/chinas-super-heav … r-station/
China’s super heavy rocket to construct space-based solar power station
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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For Louis re #138
Have you been looking for reports of tests of effectiveness of RF power transmission? It is obvious that RF is being transmitted efficiently and effectively from Geosynchronous orbit 24*7*365. What is there about that obvious fact you are having difficulty understanding?
(th)
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