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metalAZZman

Manned mission to mars

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That's the kind of thing people say every single generation.

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That's the kind of thing people say every single generation.

.

Some people indeed do say that permanently regardless of what the situation is ( and some people are permanently stuck in the opposite ). But insisting that the situation is not getting worse just because some people would say that even if it weren't, isn't the best way of dealing with the reality.

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Did you know there is an actual biological mechanism that explains the universal idiom "any time past is better"? Apparently, the negative memories are more likely to be forgotten. So we get over traumas quickly and such, an evolution mechanism.

And all I see is another fraction of the turn of the wheel.

Rune. History is an account of people repeating itself. Because people are, you know, people.

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Did you know there is an actual biological mechanism that explains the universal idiom "any time past is better"?

Yes I did. But, just because people are biased in that direction, it does not mean automatically, that the opposite is always true. Sometimes the things really go downhill.

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Yes I did. But, just because people are biased in that direction, it does not mean automatically, that the opposite is always true. Sometimes the things really go downhill.

I don't see any proof of things going downhill. I can point out much worse situations in the past compared to today. Unless you some how forgot some of the crazy hard times humanity has been through, you couldn't possibly actually think things are going down hill.

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I would like to point out the fact that my written language skills suck, (as if you couldn't tell), so most of what you're reading is not what im meaning, so some of my correct statements seem realy quite wrong just because of how I conveyed it, so sorry about that, (I am working on this).

First of all, water does work as a radiation shield, however Is a horrible idea. Shielding capabilities are not directly linked to mass, meaning that 1000Kg of water has far less shielding than 1000Kg of lead, and takes up a hell of a lot more space, so I would tend to agree with the majority of professional physicists who would suggest lead for radiation shielding...or yo could always use uranium, I hear that works well..lol, ..(It actually would work very well if it wasn't hazardous)

With the artificial gravity thing, I think my biggest problem is that I am more than likely overestimating the rotation speed required. However, I still think that artificial gravity in its current theoretical state needs a lot of work to get it to be only bearably bad (as opposed to being extremely bad). From what I can work out, any rotating room design will not allow astronauts to stand straight up (because the artificial gravity comes from the centripetal acceleration, and your tangential linear momentum, so will always be angled, so it will always feel like walking uphill (though by how much is determined by the radius and speed (which im sure Im overestimating)), and walking in the opposite direction to the rotation could lead to problems.

I still think Phobos is a bad idea for now, but yea (Im not even going to bother trying to explain this fully because you still wont believe me, and because im lazy)

I did not suggest that parachutes were the only kind of descent techniques,..when I clearly mentioned curiosity's parachute, powered descent, skycrane, technique...but anyway, I know a full parachute descent will not work with mars' thin atmosphere, and I would expect that a fully powered descent would require far to much fuel, and is just a horrible Idea, So im just sayin that the landing will require more work that anything,..then you have to remember the ascent and return.

When I suggested the electromagnet I did know that It would require a lot of energy to work, but I was just saying it.

I did not really realize that space discussions where just as bad as religious discussions lol

Also I would like everyone to take into account "Just because you are wrong, it does not mean that I am right" - me

This also goes the other way around, just because im wrong, does not make you right,.. just remember that

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Nobody will mine iron or other bulk materials on asteroid in this century, main target would be mining ice for water, oxygen and rocket fuel (to fuel future operations for lower price) and high value (rare on earth) metals like platinum (~70.000$ per kg).

If asteroid mining technology would advance, we would be able to mine other stuff and bring it back to earth in profitable amounts.

Edited by karolus10

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First of all, water does work as a radiation shield, however Is a horrible idea. Shielding capabilities are not directly linked to mass, meaning that 1000Kg of water has far less shielding than 1000Kg of lead, and takes up a hell of a lot more space, so I would tend to agree with the majority of professional physicists who would suggest lead for radiation shielding...or yo could always use uranium, I hear that works well..lol, ..(It actually would work very well if it wasn't hazardous)

Based on what I've read water wouldn't be "far less", though I guess it depends on perspective. Water has 1.5 times the halving mass of lead, meaning 100kg of lead shielding is equivalent to 150kg of water shielding. The advantage of water as a shielding technique is that water is something that already has a practical purpose on board and can safely be used in other situations and only temporarily used to enhance sheilding when, say, a solar flare comes.

I did not suggest that parachutes were the only kind of descent techniques,..when I clearly mentioned curiosity's parachute, powered descent, skycrane, technique...but anyway, I know a full parachute descent will not work with mars' thin atmosphere, and I would expect that a fully powered descent would require far to much fuel, and is just a horrible Idea, So im just sayin that the landing will require more work that anything,..then you have to remember the ascent and return.

Landing on a small body requires a lot less fuel than on a larger body precisely because of the lower gravity, and then you have to remember that the ascent is going to be incredibly easy. Because of the low gravity.

I did not really realize that space discussions where just as bad as religious discussions lol
They're only bad if you choose to take offense when you're corrected on something.

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Actually, lead is very poor space radiation shielding. Sure, it has a better halving distance, like all heavy elements. That's awesome against neutron radiation. But against high energy cosmic rays, again like all heavy elements, it produces... let me google this because the spelling is hard... Bremsstrahlung. That means secondary radiation that may actually be more dangerous than the original one. So you don't want radiation shielding that becomes radioactive, so you use light elements. And as kerbface says, water is good for other things.

As to artificial gravity, I seem to remember 3rpms at 50m radius would be nice to give some numbers. Discomfort starts at more than 6rpm according to studies. So the only factor that really matters is radius. The 10m centrifuge in 2001 was probably much, much more uncomfortable than if Discovery's hab section had been designed as a cylinder and the whole ship given a spin between burns. Much simpler mechanically too, of course.

Rune. Discovery was also supposed to have extra tanks. An radiator wings. I digress.

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Mars Explorers Face Huge Radiation Problem

http://news.discovery.com/space/mars-radiation-astronauts-health-threat-130530.htm

"A radiation sensor inside NASA’s Curiosity Mars rover shows that even under the best-case scenario and behind shielding currently being designed for NASA’s new deep-space capsule, future travelers will face a huge amount of radiation.

The results, based on Curiosity’s 253-day, 348-million-mile cruise to Mars, indicate an astronaut most likely would exceed the current U.S. lifetime radiation exposure limit during one round trip mission."

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Mars Explorers Face Huge Radiation Problem

http://news.discovery.com/space/mars-radiation-astronauts-health-threat-130530.htm

"A radiation sensor inside NASA’s Curiosity Mars rover shows that even under the best-case scenario and behind shielding currently being designed for NASA’s new deep-space capsule, future travelers will face a huge amount of radiation.

The results, based on Curiosity’s 253-day, 348-million-mile cruise to Mars, indicate an astronaut most likely would exceed the current U.S. lifetime radiation exposure limit during one round trip mission."

I still volunteer.

I SHALL DIE! FOR SCIENCE!

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Mars Explorers Face Huge Radiation Problem

http://news.discovery.com/space/mars-radiation-astronauts-health-threat-130530.htm

"A radiation sensor inside NASA’s Curiosity Mars rover shows that even under the best-case scenario and behind shielding currently being designed for NASA’s new deep-space capsule, future travelers will face a huge amount of radiation.

The results, based on Curiosity’s 253-day, 348-million-mile cruise to Mars, indicate an astronaut most likely would exceed the current U.S. lifetime radiation exposure limit during one round trip mission."

As much as I would rather see a full return trip, would the radiation still be too high for a one way trip? If we were to build a base on Mars, for example.

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I still volunteer.

I SHALL DIE! FOR SCIENCE!

I'm centrality not volunteering to die for science, but had no problem to observe others doing that... I'm terrible person :rolleyes:.

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I could be wrong, but wouldn't it be resonable to assume that a rover would have a LOT less shielding than an actual human in interplanetary space? This article just seems a little unclear on whether they're just talking about the rover's shielding not being enough for a human or any sort of practical shielding, and it doesn't really go into detail.

I mean the radiation levels can't be news, can they? Have we never monitored radiation on anything outside of the Earth's magnetic field before?

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I could be wrong, but wouldn't it be resonable to assume that a rover would have a LOT less shielding than an actual human in interplanetary space? This article just seems a little unclear on whether they're just talking about the rover's shielding not being enough for a human or any sort of practical shielding, and it doesn't really go into detail.

I mean the radiation levels can't be news, can they? Have we never monitored radiation on anything outside of the Earth's magnetic field before?

The radiation levels are indeed news, no spacecraft to my knowledge has measured radiation in deep space for any significant chunk of time. Curiosity had some levels of radiation protection for the cruise stage but the rover itself has radiation hardened parts, so obviously that level of protection would not be ideal for a human. The 662 mSv dose is a 180-day reference Mars mission using traditional chemical propulsion but with solar electric propulsion that could bring the travel time down to weeks (and thus the radiation dose received during the trip). There are other ideas such as lining a spacecraft's inner walls with water which could also help. It remains to be seen how tough the radiation environment is on Mars but I don't expect it to be greater than in deep space given the fact that Mars has a tenous atmosphere and is a large rocky body.

You would always have that risk however and another option would be to move the radiation dose limit. The career limit of a NASA astronaut is a 5% increase in the risk of developing fatal cancer, or 1 Sv/1000 mSv, but NASA tries to keep it to below 3%. This is in addition to the already huge risk everyone has of contracting cancer here on Earth (26% in the UK).

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Yes, the radiation levels are probably manageable for short duration stays on Mars surface (1 or 2 years), with appropriate shielding, limited EVA sorties, and increased dosage limits.

But it pretty much rules out any dreams of long term colonization, with children and families living off the land. There is no point in living on Mars if you have to stay dig yourself underground and never go outside. We can do that on Earth too.

Edited by Nibb31

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But it pretty much rules out any dreams of long term colonization, with children and families living off the land. There is no point in living on Mars if you have to stay dig yourself underground and never go outside.

.

Who wants seeks ways, who does not want to, seeks reasons.

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I'm always cautious about the validity of any of the space radation studies. Some types of radiation are more dangerous than others. On earth we only have to deal with Alpha, Beta, Gamma and occasionly Neutron radiation. In space there are a lot of Protons and Heavy Ions. Basics studies show that the protons are twice as dangerous as gamma rays (per unit of absorbed energy), heavy ions are about 20 times worse. But thats just killing cells in a petri dish - we have no real idea of the relative cancer risk.

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.

Who wants seeks ways, who does not want to, seeks reasons.

Yeah, but wishful thinking won't help you negate physics.

But thats just killing cells in a petri dish - we have no real idea of the relative cancer risk.

It can't be too good for your health to lose too many brain cells...

Of course, there needs to be more research in the area, but it isn't looking too good.

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Yes, the radiation levels are probably manageable for short duration stays on Mars surface (1 or 2 years), with appropriate shielding, limited EVA sorties, and increased dosage limits.

But it pretty much rules out any dreams of long term colonization, with children and families living off the land. There is no point in living on Mars if you have to stay dig yourself underground and never go outside. We can do that on Earth too.

Not never go outside.

Just limit the exposure risk. You could live underground while preperations for a surface base were made.

Although that might as well be done by robots.

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Yeah, but wishful thinking won't help you negate physics.

.

giving up before even trying won't either.

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.

giving up before even trying won't either.

Sometimes, you have to recognize a lost cause. There is no point in fighting an uphill battle when there are no benefits to gain in the end.

Some things in life are impossible. Some are hard, but feasible. Others are hard, and not worth the effort.

Not never go outside.

Just limit the exposure risk. You could live underground while preperations for a surface base were made.

Although that might as well be done by robots.

Yeah, but what for? In what circumstances would it be desireable for Humanity to establish a colony on an uninhabitable planet where people have to live underground and hardly ever go outside? Even if some major catastrophe rendered Earth uninhabitable, it would be easier to do the same on Earth.

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Yeah, but what for? In what circumstances would it be desireable for Humanity to establish a colony on an uninhabitable planet where people have to live underground and hardly ever go outside? Even if some major catastrophe rendered Earth uninhabitable, it would be easier to do the same on Earth.

There are many reasons.

The one thing Mars One has shown, is that there are quite a few people who would be willing to live on Mars, just because they "can".

If people were willing to sacrifice some freedoms they get on Earth, there would probably also be large profits to be made from any unexploited resources, or even simply terraforming real-estate to make it more Earth-like.

Then of course you have money to be made off tourism.

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Sometimes, you have to recognize a lost cause. There is no point in fighting an uphill battle when there are no benefits to gain in the end.

.

Yeah right. Give up on the rest of the universe, there are no benefits to gain there. It is a lost cause, just sit quiet here and wait for the next mass extinction.:mad:

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