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#601 2021-11-04 14:29:13

kbd512
Administrator
Registered: 2015-01-02
Posts: 5,137

Re: Going Solar...the best solution for Mars.

SpaceNut,

The US had its first armed combat drones in 1944, but they were never used in combat.  We had experimented with RC drone aircraft for at least a decade at that point.  I think some of our first experiments with remotely piloted aircraft were not long after WWI, meaning 1920s.  The Naval Aircraft Factory TDN-1 RPV was an optionally piloted twin-engine drone aircraft equipped with a single 2,000 pound iron bomb or Mk 13 torpedo.  4 prototypes and 100 operational examples were built during the war.  As previously stated, tested in mock combat, but never used in actual combat.  These aircraft were of wooden construction, had fixed tricycle landing gear, operated from carrier flight decks like normal carrier aircraft, and contained a television camera or radar system with the signal relayed back to a remote viewing station aboard a TBM Avenger aircraft located up to 8 miles away.  Experiments were also conducted with a single airborne operator controlling multiple drones at the same time.

We had fully autonomous radar-guided glide bombs (the ASM-N-2 Bat was used operationally in the Pacific theater of war) that successfully sank or heavily damaged a number of Japanese ships in the Pacific.  These guided weapons were equipped with 1,000 pound warheads from regular iron bombs.  They were constructed of plywood, used Lead-acid car batteries to power the radar and flight control servos, were fire-and-forget weapons rather than radio-controlled / remotely-piloted, the airframe and electronics weighed 600 pounds, the weapons attained glide speeds of 140 to 210 knots, and a few dozen or so were used in successful attacks at ranges of up to 20 nautical miles when dropped from 25,000 feet.  The length was just shy of 12 feet and the wingspan was 10 feet.  The Bats entered into service in 1945 and were carried into combat by Corsair fighters, Catalina flying boats, and Privateer heavy bombers.  2,580 of these Bat glide bombs were built.

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#602 2021-11-04 17:11:43

louis
Member
From: UK
Registered: 2008-03-24
Posts: 7,097

Re: Going Solar...the best solution for Mars.

I was amazed to read a few years ago that the Russians had (small) "robot" tanks, rado guided I think,  that they used in WW2.

kbd512 wrote:

SpaceNut,

The US had its first armed combat drones in 1944, but they were never used in combat.  We had experimented with RC drone aircraft for at least a decade at that point.  I think some of our first experiments with remotely piloted aircraft were not long after WWI, meaning 1920s.  The Naval Aircraft Factory TDN-1 RPV was an optionally piloted twin-engine drone aircraft equipped with a single 2,000 pound iron bomb or Mk 13 torpedo.  4 prototypes and 100 operational examples were built during the war.  As previously stated, tested in mock combat, but never used in actual combat.  These aircraft were of wooden construction, had fixed tricycle landing gear, operated from carrier flight decks like normal carrier aircraft, and contained a television camera or radar system with the signal relayed back to a remote viewing station aboard a TBM Avenger aircraft located up to 8 miles away.  Experiments were also conducted with a single airborne operator controlling multiple drones at the same time.

We had fully autonomous radar-guided glide bombs (the ASM-N-2 Bat was used operationally in the Pacific theater of war) that successfully sank or heavily damaged a number of Japanese ships in the Pacific.  These guided weapons were equipped with 1,000 pound warheads from regular iron bombs.  They were constructed of plywood, used Lead-acid car batteries to power the radar and flight control servos, were fire-and-forget weapons rather than radio-controlled / remotely-piloted, the airframe and electronics weighed 600 pounds, the weapons attained glide speeds of 140 to 210 knots, and a few dozen or so were used in successful attacks at ranges of up to 20 nautical miles when dropped from 25,000 feet.  The length was just shy of 12 feet and the wingspan was 10 feet.  The Bats entered into service in 1945 and were carried into combat by Corsair fighters, Catalina flying boats, and Privateer heavy bombers.  2,580 of these Bat glide bombs were built.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#603 2021-11-04 20:35:02

kbd512
Administrator
Registered: 2015-01-02
Posts: 5,137

Re: Going Solar...the best solution for Mars.

Louis,

I went back and checked.  The US started initial drone aircraft experiments much earlier than I recalled, around 1910.

The Russian Teletank was a very impressive radio controlled machine, able to execute up to 24 different commands.  They were much further along than any other nation in the realm of unmanned ground vehicles.

The Germans had much smaller wire-controlled tracked bombs, nicknamed Goliath.  The first variant was battery powered.  It was pretty useless, so they replaced the batteries and electric motors with a small 2-cylinder combustion engine, increasing its operational range by 10 times over the battery powered vehicle while also permitting the explosive charge it carried to be increased from 60kg to 100kg.

The US experimented with RC vehicles for decades before WWII, but never fielded any remote vehicles until long after the war.  The Luftwaffe dispatched both crewed and radio-controlled Russian tanks with reckless abandon, so that was probably for the best.  Still, it would've been nice to have a remote-controlled lead tank since those tended to be the first to get hit when ambushed by anti-tank guns or other tanks.

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#604 2021-11-19 15:05:09

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 8,653

Re: Going Solar...the best solution for Mars.

https://currently.att.yahoo.com/finance … 00939.html

The so-called Antípodas project will be based on the enormous solar energy potential of Chile’s Atacama Desert, the driest non-polar desert in the world. While temperatures in the Atacama are usually relatively temperate, they can soar to 130 degrees Fahrenheit (50 degrees Celsius). The almost entirely cloudless desert is the region in the world with the highest rates of solar radiation, making it a prime location for a solar farm.

Getting all that solar energy to Chinese markets, however, may be tricky. On top of the hefty price tag of the cable itself, China will have to seriously invest in building out its solar plant infrastructure in order to make way for Chile’s prodigious 3,106 MW of already-installed photovoltaic capacity. It will also require a lot of geopolitical dealmaking between Chile, China, and other Asian economies.

For Louis !!!

(th)

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#605 2021-11-19 15:36:23

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 24,442

Re: Going Solar...the best solution for Mars.

A really long power cable for sure....and longer going to mars....

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#606 2021-12-03 20:22:44

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 24,442

Re: Going Solar...the best solution for Mars.

I will move this if I am in the wrong topic

https://mars.nasa.gov/files/resources/M … _Final.pdf

Power for orbiter:
More than 2,000 solar cells on four panels, covering 129 square feet (12 m 2) .
Solar panels generate between 1,150 and 1,700 watts . Wattage depends on the spacecraft’s position in Mars orbit .
The panels power two 55-amp-hour Lithium ion batteries

Orbit is elliptical; distance from sun varies from a minimum of 128 .4 million miles (206 .7 million km) to a maximum of 154 .8 million miles (249 .2 million km); average is 141 .5 million miles (227 .7 million km)

Revolves around sun once every 687 Earth days
Rotation period (length of day): 24 hours, 39 minutes, 35 seconds (1 .03 Earth days)
Poles tilted 25 degrees, creating seasons similar to Earth’s

Average diameter 4,212 miles (6,780 km)
Lowest orbital altitude: 77 .6 miles (125 km) above Mars surface, within the upper atmosphere
Highest orbital altitude: 3,864 miles (6,220 km) above Mars surface

This will support a mars solar ring structure to beam energy or to be made of for the atmospheric drop to create a balloon platform ring around mars.

https://ntrs.nasa.gov/api/citations/199 … 010257.pdf
Solar Radiation on Mars: Stationary .... Photovoltaic Array

https://ntrs.nasa.gov/api/citations/200 … 191326.pdf
Mars Solar Power for the mars polar lander mission support

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#607 2021-12-12 13:18:38

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 24,442

Re: Going Solar...the best solution for Mars.

This is a diy home build but its the information that we can make use of.

https://youtu.be/vng-CACPow0
Our Complete Solar System Cost With Battery Backup! 10kw Of Power

https://www.signaturesolar.com/?ref=cou … experience
all of our solar components at Signature Solar

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#608 2021-12-12 19:05:39

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 1,267

Re: Going Solar...the best solution for Mars.

SpaceNut wrote:

yes a battery can be a ripple current feature that means you are doing direct near full conversion to use with little being saved into long term storage.

This is a large thread and I'm still getting through it and I don't know if this was already discussed on this thread but has anyone looked at beaming energy Space Solar Power by microwave or laser and through Satellites into the Colder regions on Mars and use Satellites to beam and transport energy as a Possibility?

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#609 2021-12-12 19:12:42

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 1,471

Re: Going Solar...the best solution for Mars.

Mars_B4_Moon wrote:
SpaceNut wrote:

yes a battery can be a ripple current feature that means you are doing direct near full conversion to use with little being saved into long term storage.

This is a large thread and I'm still getting through it and I don't know if this was already discussed on this thread but has anyone looked at beaming energy Space Solar Power by microwave or laser and through Satellites into the Colder regions on Mars and use Satellites to beam and transport energy as a Possibility?

It has been discussed and is a good idea.  If we are relying on imported solar power infrastructure, then beyond a certain power output it may make sense leaving the panels in Mars orbit and beaming the power to ground.  That critical size will be in GW power range.


"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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#610 2021-12-29 11:43:30

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 24,442

Re: Going Solar...the best solution for Mars.

I continually look for what is being sold as kits for being able to deploy solar at a reasonable cost for home use and I keep finding specifications that are getting blurred and the actual performance is not really what is being advertised.

I was looking for a sine wave battery inverter for use for creating line voltage but some of these state Expertpower 2.5KWH 12V Solar Power Kit | Lifepo4 12V 100Ah, 400W Mono Solar Panels, 30A MPPT Solar Charge Controller, 3KW Pure Sine Wave Inverter

First clue is they try to give you the kwhr ratings and since this is solar means they are trying to calculate best alignment and max hours to store. Of course that is in a 12v at 100Ahr = 1,200 whr so we must have more than 1 battery to achieve the storage. It says that the inverter is 3kw and that means the Ahr and battery count are off..

It is soldon Amazon with same tag line

This Off-Grid Solar System Kit includes two 12V100Ah LiFePO4 batteries, 4 x 100W Monocrystalline Solar Panels

2.5kwhr means we are to get the panels to receive 6.25 hrs of direct sunlight to achieve that rating, which means that is not happening.

The 2 batteries in parallel means we have a working wattage of 2,400 watts for an hour of power we can draw from with the kit having the 200 Ahr battery option which would double that for 4,800 watts for an hour to start with for usage which is closer to the inverter rating. Of course when we use power we are not paying attention to any of these values so one 1500w appliance would get just 2 hours of use from the device.

That make is plausible for Th use with batteries fully charged and not hauling the panels around but we would need many of these for a human use.

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#611 2022-01-09 17:24:23

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 24,442

Re: Going Solar...the best solution for Mars.

kbd512 wrote:

tahanson43206,

Mars is so energy-poor that any significant settlement will require nuclear power.  No amount of "green ideology" will affect the fact that anyone living on Mars, energy-wise, is between a proverbial "rock and a hard place".  The energy usage at our Antarctic research station is sky-high, yet they produce no food for themselves, no atmospheric breathing gases are produced or recycled, no construction takes place on-site except using diesel powered machinery, and they do very little in the way of waste water recycling (they treat grey water and then they discharge it, because they're literally sitting on a functionally limitless supply of fresh water).  To support those very limited scientific research activities in the Antarctic, they burn an incredibly amount of diesel fuel each day.  The researchers do get supplemental power from wind, solar, and batteries.  Antarctica is rich in wind, but relatively poor in solar.  There's no usable wind power or hydro power on Mars, which leaves solar and batteries as the sole alternative, which also happens to be the least energy-dense form of fuels that humanity has learned how to use.

We supply 300,000 liters / 79,250 gallons of diesel fuel per year, in order to support 10 (winter) to 80 (summer) people.  Each gallon of diesel fuel represents 40,700Wh of thermal power, or 3,225,475,000 / 3.2GWh of power for 10 to 80 people over 1 year.  Each kilo of U235 is 24GWh per kg, if fully consumed in a nuclear reactor.  To supply daily power, batteries would have to store 8,836,918Wh, and to have any kind of reasonable battery life, that has to be doubled to 17,673,836Wh.  That equates to 70,695kg of batteries, which is either at or over the shipping weight of 10MWe class truck-transportable nuclear reactor cores.  If we're lucky, those batteries might last for 10 years (3,650 charge / discharge cycles) before replacement is required.

Mars InSight lander has an active array area of 5.14m^2 and generated approximately 4,600Wh on Day 1 (IIRC, actual output was 4,585Wh or thereabouts).  That equates to 895Wh/m^2 of "Day 1" / "perfectly clean" output.  Total array output dropped like a rock to, IIRC, a mere 700Wh in less than 2 years, due to accumulation of atmospheric dust.  Therefore, solar arrays DO have to be kept clean on a routine basis to prevent dramatic loss of power output.  We will assume that we can clean the arrays, though, because we do that in the deserts here on Earth, where it is equally necessary to maintain output.

That info comes from this document.  This is a comprehensive analysis of measured versus estimated output using state-of-the-art photovoltaic array equipment optimized for LILT (Low-Intensity / Low-Temperature) conditions:

Scientific Observations With the InSight Solar Arrays: Dust, Clouds, and Eclipses on Mars

Maximum Wh/m^2 is therefore around 900Wh/m^2 on Mars, under ideal conditions using 35% efficient triple-junction Silicon wafer-based photovoltaics with a very thin but very hard cover-glass that prevents the crazing problem that both Robert Dyck and myself have stated is a real issue with soft plastics.  Therefore, an absolute bare minimum of 9,819m^2 of array area (99m by 99m; a professional soccer field is 7,140m^2 and a NFL football field is 5,351m^2, for comparison purposes), at 900Wh/m^2, is required to supply power before any losses are taken into account.  Recall that here in Texas 23% of the electrical power is lost in the wiring and PMAD (Power Management And Distribution) equipment before the power touches the main line that feeds it into the grid.  Using my proposed 2kg/m^2 advanced CFRP / Kevlar honeycomb backer board with the same wafer-based photovoltaic panel design with 0.5kg allocated to a CFRP or CNT support structure (vastly lighter than anything used commercially here on Earth and lighter than ISS arrays), we're looking at 24,548kg for the panels without any wiring or PMAD equipment.

I don't know what voltages would be used, but if we use a small town photovoltaic array as our facsimile, then I estimate another 5,000kg for wiring / PMAD / circuit breakers using lightweight equipment, assuming Aluminum wiring is used.  CNT is likely required to achieve that mass target.  We can only be so smart about how we wire the panels to minimize wiring runs, and the more amps of power we provide, the thicker the gauge of wiring required.  Looking at lower output Earth-bound arrays, we'll see that 5,000kg is much nearer to a pipe dream than a practical tonnage figure.  In all probability, the wiring and PMAD mass will be a significant fraction of the array mass than my optimistic estimate, but let's be "dreamers" here.

That's around 100t to supply power for 10 people in Antarctica or on Mars, where the life support power requirements are much much higher.  The batteries, which represent 70% of the equipment mass, will not last more than 10 years before replacement is required.  If we assert that that amount of power could also keep 10 people alive on Mars (even though it cannot if food must be grown, CO2 scrubbed, and water ice melted for consumption).  That equates to 10,000,000,000kg / 10,000,000t for a 1,000,000 person Mars colony.  Total mass of all objects sent into space is 9,800t, but we'll call it 10,000t for easy math.  This 1,000,000 person Mars colony therefore requires 1,000X as much mass, not to Earth orbit but to Mars- "JUST" TO PROVIDE BASIC LIFE SUPPORT POWER, NO FOOD OR ISRU, IF WE INSIST ON USING PHOTOVOLTAICS AND BATTERIES!  Anyone who thinks that's practical to do is living in their own personal fantasy land.  That's 100,000 launches at 100t per launch, except we need 6 to 8 launches to deliver that tonnage to Mars, which means 700,000 launches.  At a mere $2M USD per Starship launch, that's $200B per 100,000 launches, or $1.4T USD for 700,000 launches.  You have to wonder about their inability to do basic math and accept.  We have to replace 70% of that mass every 10 years and 90% to 100% every 25 years, until 100% of the colony's power requirements are met by local production.  If it takes 25 years to grow the colony to 1,000,000 colonists, how practical does that seem to you?

We could obviously set up a photovoltaic or battery manufacturing plant on Mars using ISRU, but what would that require?

More equipment mass, more input power, more people to work in the factory, which in turn requires more mass and power...  It's a vicious cycle.

It's a fool's errand.  It's a fantasy-based proposal from people who refuse to accept basic math, because the results of the equations are so devastating to their ideologically-motivated beliefs.  Similarly, my admonishment to use simpler but more reliable and longer-lived heat engines, despite having a lower overall efficiency, is all about basic math.  Anyone who asserts that math doesn't matter does not believe in science, they believe in their own form of religion.  Those who know me also know that I am not a fan of any kind of religion, and have a particular mistrust of organized religion.  This is the reason why- the solutions they come up with are seldom, if ever, practical solutions that can be applied to a real world engineering problem.

Recall that at least several times I've stated that fission power alone is not enough, and that we probably need fusion power, in addition to the fission and solar thermal heat engines to generate the staggering amount of power required.  Power production is and always has been the name of the game.  You need mass and energy devoted to every other aspect of life apart from merely generating or storing enough power.  The use of low energy density batteries drastically adds to the total mass of the solution.  The greater the tonnage of power generating or storage equipment you have to ship, the less tonnage devoted to every other aspect of living on Mars.  I go over this aspect of living on Mars again and again and again, because it dictates how fast the colony can grow and how many people it can realistically support at any given time.  There are no other "natural resources" that can be used without the master resource- ENERGY!

It's not my fault that existing energy generation and storage technology does what it does, and can do no more.  That's the entire reason we continue to pursue fusion power.  Every big "jump up" the "order of magnitude scale" that you make, with respect to energy output, the greater the technological capabilities of your civilization.  None of it is truly "clean", none of it is truly "renewable", it's just a question of trade-offs and what you want to devote energy output to- "making more energy" with diffuse / intermittent power sources, or "all other human activities" with reliable and continuous generation with minimal "natural resource" consumption.  The more you understand of the basic math involved, the less prone you are to having someone sell you a bill of goods that does not meet or even approach the terms of the sales pitch.

If it was up to me, we'd be using hydro / geothermal / solar and nuclear thermal engines to power human civilization while devoting all available brain power and funding to fusion power.  Whereupon we have pervasive deployment of practical fusion reactors, then we can supply the electrical power to attempt to electrify nearly every aspect of human life- from transportation to home heating.  We also have excess power to tinker endlessly with photovoltaics and batteries (satisfy the curiosity or religious beliefs of scientists and environmentalists), with virtually no threat to the continued existence of a technologically advanced human civilization capable of space flight and colonization.  Unfortunately, politics and ideology have been unrecognizably contorted to promote a self-destructive anti-humanist ideology of scarcity and austerity, which have historically been abject failures every single time they're attempted, much like communism.  I like the arts and artists, so to preclude energy poverty from forcing those people to instead become farmers or mechanics or pursue any other career path for which they are manifestly unsuited, humanity requires abundant power / food / clothing / shelter / medical care (all the "good stuff" that comes from energy abundance).  Abundance only continues while the machinery of human civilization is kept well-oiled and humming along at full output.

Anyway, at this point I've restated this in as many different ways as I know how.  Some people will "get it", while others will not.  I have nothing against using any form of power, but its limitations should be well known unto its users and respected as such.

Another why we will use solar once we establish a real power source as nuclear

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#612 2022-01-15 18:57:07

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 24,442

Re: Going Solar...the best solution for Mars.

Recycling solar panels to help climate crisis

Ph.D. student, Natalie Click, shares how solar panels can be recycled to cut costs and help fight against climate change.

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