The Moon or Mars:

I just tried to read Billvon's link:
A recent design paper by Dr. Jaffe from the NRL examined (and then tested) the temperature rise for solar power satellites. Assuming 28x28cm "tiles" radiating from both sides, and assuming multijunction cells about 30% efficient, you get a temperature rise of about 50C above radiative ambient - not too different from terrestrial modules. http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6187077

I could not get to the article. I don't even know if the "tiles" are fully covered by solar cell on one side or if part of that same side is reflecting sun light to make the average absorption coefficient much lower / less heat per unit are to ge rid of.

The little I could read suggest multi-layer cells to boost the fraction of the solar energy converted to electric form and that would be a big help with the thermal problem too, but more costly than single band gap cells. For example if 30% is converted to electric energy then only 70% is heat to get rid of (not about 90% as I discussed.) Also the absence of any thing close by absorbing the radiate IR and getting hot or reflecting part back helps compared to moon (or Mars) surface being hit by it all.

 

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That is just reassertion of yours repeated many time without proof. I asked you:

" On (1): Please pick one of the reasons I have given and tell why it is not valid."

But you seem not to be able to refute ANY OF my arguments why it is IMPOSSIBLE to build a self-sustain "life boat for humanity" any where off earth, but the moon.

BTW, Lord Kelvin was basing his argument as you do - on history, not physics. Yes man has made great technical advancements, but that does not mean, as you think, "any thing is possible" with time.

 

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I lost continuation of my post, so here it is again, in brief:
Not everything is possible with time. For example travel to another star system by man is impossible. You would need to be in a central cavity of a spherical mass about equal to one of the Navy's destroyers to be shielded from high energy cosmic rays. Your cavity needs space to grow your food, recycle your CO2 and feces, etc.

To launch that destroyer mass spherical shell from earth would require fuel mass greater than the earth's mass (quick guess) AND the pressure force on the launch pad would liquefy steel.

 

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If you're talking about post 12, I see claims and that's all.
On Lord Kelvin, he was basing his arguments on what he believed at that time, only a decade or so before the Wright Brothers. A great man no doubt, but like many people, great or otherwise, are snowed down into what technology presents at that time.
I stand by my claim that in time, we will not only have a base on Mars but also on other distant solar system bodies, perhaps Mercury.

There is only one sensible logical way to improve our lot on Earth. And that isn't taking away from space endeavours.
The money that can be saved from eliminating all the militaristic endeavours, would amply suffice.
It's absolutely crazy to take it from NASA or any other space agency, considering the advantages that the space age has already achieved for humanity as a whole.
Again, I would see it as a united International effort, particularly once we have it in our mind to head for the stars.
In time, that also will most likely happen.

 

Not just "claims" but facts like the following from post 12:

That is basically the economic argument against trying to make a "life boat" for humanity on Mars. As others have noted too, there is no financial return - just huge costs.

The other main reason (damage to crew by high- energy cosmic rays, both in the 180 or so days of the trip and after there with little atmosphere or magnic shielding) is dispersed in several posts.


I again (third time) ask you to refute either.

 

The billions and billions go back into the world economy. Some folks must think it gets flushed down the toilet. More jobs more money into the worlds economies.

 

In his post 32, orcot mentions He3 in the last paragraph, noting or inferring it may be useful in 2nd generation fusion systems (first has been only about 10 years from demonstation of success for the last five decades. I worked on that problem in at APL/JHU when joining in 1958! The US Navy paid our small group, as by 1970, they expected to place and order for world's first fusion powered aircraft carrier! APL has long history, even back then of helping Navy technically over see large contracts.

He3 is definitely bombarding the moon's surface from solar radiation, and the only thing not ridiculously more expensive to bring back to earth (instead of make here) so is usually mentioned by space enthusiasts as a possible economic reason for mining surface layers of the moon. However in post 36, orcot also notes that the surface temperature on the moon get up to at least 350K. I add that all form of helium are extremely capable to escape thru the tiniest cracks .(Why it is used as a "sniffing gas" when looking for leaks in in vacuum system). Helium is the smallest atom that exists, much smaller than hydrogen as it two electrons are also in the smallest quantum number shell, but bound / attracted to the nucleus by twice the charge. - smaller orbit about the nucleus.

Thus it is very likely that there is practically none in the "moon dust surface" I.e. it rapidly "out gases" from the hot surface to the vacuum. AFAIK, none has been found in the sealed bags of moon dust returned to earth.

 

I refute both simply because of your "impossible" scenario.
Economic conditions and such change with time, including people's attitudes.
Technology improves with time, and solutions are actively searched for to combat difficulties and dangers.
http://science.nasa.gov/science-news/science-at-nasa/2004/17feb_radiation/
http://source.colostate.edu/space-radiation-csu-studies-the-risks-for-astronauts-journeying-to-mars/
http://www.wired.com/2014/04/radiation-risk-iss-mars/

http://www.space.com/24731-mars-radiation-curiosity-rover.html
http://www.sciencedirect.com/science/article/pii/S2214552414000042
I have yet to see anyone use the word impossible......in fact while recognising the dangers and difficulties, those at the coal face are still researching and are confident.
http://www.centauri-dreams.org/?page_id=2118
http://100yss.org/mission/team
http://www.mars-one.com/

Never say never.
Still if you chose to remain so pessimistic, that's your choice.
I'm still hoping it will be achieved in my lifetime, and certainly within my children's lifetime.

 

Yes, spending would pump money into the economy and add to the already un payable debt but no more so than hiring several thousand men to dig ditches and an equal number to fill them up the next day.

 

Simple fact: The beginning of the space age and Sputnik and SATELLITES.
Where would humanity be without Satellites?
Think of the advantages that have flowed through to meteorology, Agriculture, GPS, and a host of others.
The simple old basic Satellite!

 

You're surely the wrong person to be making predictions about the worlds economic future. Considering your past predictions. LOL. How much time did you spend blowing smoke up your own ass Nostradamus?

 

"No pessimist ever discovered the secret of the stars, or sailed to an uncharted land, or opened a new doorway for the human spirit".
Helen Keller:

 

paddoboy's first link: http://science.nasa.gov/science-news/science-at-nasa/2004/17feb_radiation/ ends with:

"Can people go to Mars? Cucinotta believes so. But first, "we've got to figure out how much radiation our bodies can handle and what kind of spaceship we need to build." In labs around the country, the work has already begun."

Note NASA has considerable vested interest in avoiding a negative answer to this question.

Your 2nd link is just getting started :http://source.colostate.edu/space-radiation-csu-studies-the-risks-for-astronauts-journeying-to-mars/
But It found WITH NEUTORN BEAMS:
"In these studies, Weil’s team found that space radiation is no more likely to cause leukemia than terrestrial radiation.
“However, we found quite by accident that space radiation is 50-fold more effective than typical radiation on Earth at causing a type of liver cancer called hepatocellular carcinoma,” he said.

Collaborators in the new project include Dr. Douglas Thamm, a CSU veterinarian and cancer researcher who holds the Barbara Cox Anthony Chair in Oncology; he will study why simulated space radiation causes certain tumors to spread, or metastasize, more readily."

Billy T notes:
Neutron beams produce little if any ionization damage - only the direct and highly unlikely collision with a nucleus does much. It is less than one chance in a million, as nucleus is at least 1000 times smaller than the atom the beam passes thru (actually much less as most atoms in man are much larger than the hydrogen atom)

This "test" ignoring ionizing charged particles of cosmic rays is IMO designed to conclude: "There it tolerable danger." It is the ionization that causes almost all the damage.

Your third link: http://www.wired.com/2014/04/radiation-risk-iss-mars/ is the only one not directly funded by NASA so I will quote many paragraphs from it IN FULL. But first note the title of article is:
"Space Radiation Remains Major Hazard for Humans Going to Mars"

SUMMARY: Only NASA funded studies express any optimism. Why am I reminded that only the Univerity of Iowa, found that corn based alcohol had a slight positive gain in energy. I.e. ERoEI = 1.1 or 1.2, the Cornell study found it to be about 0.7

 

I did not make any prediction in the post you reply to. I only observed the absolutely true fact that if the government creates and funds any new project, such as digging holes and filling them later*, that adds money to the amount in circulation (all else remaining the same). I did predict more than seven years into the future that the US / world economy would be in deep trouble by Halloween 2014, and it does seem to be propped up by central banks printing money on a scale I did not think they would. I. e. I got the timing wrong - perhaps it should have been 8 or 9 years in to the future. Attack what I said, not me.
* Or sending men to Mars.
PS Again what I have said is impossible is building a self-sustaining "life boat" for humanity off the earth any where but on the moon.

 

I gave all those links Billy, because they give the facts as is. No one has ever denied dangers and difficulties once we venture outside Earth's atmosphere.
No one even hints that it is Impossible.
Many experts, much much smarter than you and I are working on the problem/s.
Many reputable, learned people are working to achieve the inevitable. People such as Marc Millis and Mae Jemison.
All are working with a goal in mind. That goal is to put men on Mars, and do it as safely as is humanly possible, with total regard to their health.
In all honesty I fail to see how anyone can sit/stand there, and say it is Impossible to have human habitation/outpost beyond the Earth/Moon system.

 

Colonization of Mars
From Wikipedia, the free encyclopedia

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An artist's conception of a human Mars base, with a cutaway revealing an interior horticultural area
Mars is the focus of much speculation and scientific study about possible human colonization. Its surface conditions and the likely availability of water make it arguably the most hospitable of the planets, other than Earth. Mars requires less energy per unit mass (delta-v) to reach from Earth than any planet except Venus. However, at minimum energy use, a trip to Mars requires 6–7 months in space using current chemical propulsion methods.
http://en.wikipedia.org/wiki/Colonization_of_Mars

It's just a matter of time.

 

Saying "it is impossible because it would require something that is provably possible to construct" doesn't make much sense.

Yes, which we are already doing to a limited degree on the ISS (and have done on a much larger and more complete scale for two years here on Earth.)

1) Why does it have to be launched from Earth? I'd think you'd want to build it in orbit.
2) Why do we care if we liquefy steel, if we want to launch it from Earth? (Still not a great idea, but a propulsion system like the Orion nuclear pulse engine could handle lifting that sort of load.)

 

Another problem with mars would be the challenge to reach it over to challenge to do anything meaningfull on it. One of the mayor problems abouth the lunar program it seems is that people where sort of clue less on what to do on the surface. A lunar focussed program has much more to proof on that front.
I believe a martian base would be (much more then the moon) be focussed on building up infrastructure on Mars. On Luna the possibility for a export towards earth is far easier. The delta v to return something from the moon is 2.3 whilst for mars it is 6.4 (and can only happen periodically and takes a 180 days travel time).
Meaning infrastructure on the moon has far more potential to suppport the solar system then that of mars, martian infrastructure will help... constructing martian infrastructure.
Both are equally good if unlimited funding was avaible, but if they expect a return on investment Luna is probably better.
At least for the moon the possibility of constructing for example solar panels that can beam energy back to earth, certain minnerals like helium 3 even toerism it takes 3 days to reach the moon if you are insanly wealthy and could yust buy your way in, then you could be back in a week. For Mars under the best conditions you will probably lose a year and significant bone mass.
Take in account teleoperations and you might as well drive something on the moon for a couple of hours without leaving your continent in near real time 3 seconds delay could be acceptable if not for the ultra rich then for prominent scientist who could be convicend to immigrate for the change to vitually walk on the moon pick up a real rock and send it back to earth. It also allows for specialist that could not physically make the trip but would have something to contribute on the surface itself.
also theirs the possibility that you could bring sending equipment that can replace certain sattelites for earth not all satelites are geosynchronous and placing them on the surface means they do not need their own power source and fuel their electronics could be better protected from radiation and theirs people nearby that can perform repairs and upgrades.

True the moon is lacking in key components mostly carbon and hydrogen and will probably never be a real home but it's a decend job. And honnestly you better first get a decend job before you get a decend home.

 

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This is good compliment to my suggestion of algae flowing thru transparent tubes as the most feasible food production system for the "life boat" colony as it may make recycling of non soluble part of fesses possible. I'm not sure, too lazy to check, but think algae is much more productive of food for the energy supplied to it. As the LEDs making the light could be a narrow linear strip on one side of the tube, with highly reflective film on all the remaining tube surface I think that you would get at least 100 times more food per watt powering the LED lamps compared to the "growing in dirt" approach. I. e. Perhaps on your birthday, your get to eat one tiny carrot, instead of standard processed algae.

I did not read the Wiki article, yet. How do they make the energy powering the artificial light? I also have not tried to compute but guess more than 90% of the energy needs are for food growing, and recycling CO2 back to O2 and carbon of some useful form.

 

Well, until you get an infection in your algae, and you lose your only food source. Those systems are pretty fragile. Perhaps a good option here on Earth to make biofuels, where the loss of a crop for a year isn't fatal.

Why LED's? Plastic greenhouses. If you are really worried about radiation (and you don't have to be) then put the farm in a cave and use mirrors. It's always easier to use something directly than indirectly. And since Mars has a close-to-24 hour day/night cycle, you don't need to mess with that.