piccolo's thread has sparked a small debate and Neil Black suggested taking it to a new thread... To recap,...

Personally I'm on the fence. It might be feasible with today's technology, but I'd say it's a stretch... There are a lot of known challenges to overcome and a lot more that we haven't even thought of yet.

OK, I see some problems in flying a manned spacecraft to mars.

1. Exposure to cosmic rays and other forms of radiations.
2. Psychological stress - being away from Earth, living in such a tight room with other people
3. No advanced medical facilities.
4. Problem of being in the spacecraft for too long without gravity.

Sure, you could ignore all these and risk the lives of humans just to get someone to Mars. If that is the case, theoretically, it is possible to send a manned mission to mars. But practically, I don't see it happening in the near future.

IIRC, the space shuttle is somewhat shielded from cosmic radiation. I assume with the right budget they could do a lot better job too.

Well currently humans do spend long periods of time in small spaces... Submarine missions are often 6 months at a time, IIRC, and I think astronauts in space stations spend 6 months or more as well... Albeit, a trip to mars would probably take years...

In theory you could send enough supplies with them as well medical personnel. If they were going to actually survive on mars they would need means to sustain themselves so you would have to send everything... Means for oxygen, food, energy, etc...

Gravity can be simulated with centrifugal force (i.e. the inside of the shuttle would rotate, pushing you against the outside walls -- which would be the "floor").

1. This is an issue even if you fly to Moon and it can be solved.
2. That is a problem unless you put them asleep or select highly trained professionals, who has been for some time on ISS and send psychologist/therapeutist with them.
3. This one is shame, if something terrible happens out there.
4. Can be overcome either by daily excercises or by having emulated gravity by centrifugal force.

I read somewhere that everything they ever studied in Skylab, Mir and ISS is how this and that works in non-gravity environment. One would think, with those spent billions, all problems would be solved by now.

Thanks for making this thread.

EDIT:

Sorry for the book.

END EDIT:

The attempt would face many challenges. The first challenge would be getting someone to actually attempt it. There aren't many governments with the resources to fund a project like this, and it's possible that no one government could fund it. Convincing a nation or a group of nations to take on this project would be the first step.

But speaking purely of whether or not we're capable of colonizing another world, let's look at the possibilities.

Earth Colony:
Basically a second attempt at the Biosphere 2 project. After all, if we can't manage a closed system here on Earth, could we do it on another planet altogether?

Orbital Colony:
A space station would be a much better proof of our ability to maintain a closed system than anything here on Earth could. But an orbital platform is differs from an actual colony in several regards, such as lack of gravity, and still being close enough to Earth to receive help in an emergency.

Lunar Colony:
A colony on the moon would be the first step towards real colonization. Supplies and materials could still be ferried from Earth, but the cost of doing so would mean that building a self-supporting colony would be a priority for whoever was funding the project.

Martian Colony:
A Martian colony would need to be almost completely self-supporting. Current technology gives a minimum travel time from Earth to Mars of about six months, when the two planets are aligned just right. These trips would also be incredibly expensive, plus communications would have a long delay that would prohibit real-time discussion or anything close to it. A Martian colony would be effectively cut off from Earth.

Further Colonies:
Several moons of Jupiter and Saturn have been noted as possible colony sites in science fiction. But the cost and relative uselessness of these colonies will probably prevent anyone from building them unless humanity become active in the outer solar system.

Of course, selecting a site isn't the only thing. We must also build a ship to take the colonists and their supplies and materials to the site. For my purposes I will briefly discuss the needs for a colony that is at least as far as Mars.

The ship would have to carry enough colonists for a stable gene pool. I'm not sure how many people this would be, but it would probably be several hundred at least. The ship must carry enough supplies to keep them alive, and enough materials for them to build a colony on the site. It would basically need to be an Orbital Colony itself to sustain the population while the surface colony was built.

Before we can design the ship we need to know who is going to be on it, not specifically who but at lest how many people and what specific equipment and supplies they will need. Specialists such as doctors, engineers, technicians, farmers, ecologists, and even simple laborers will all be vital to the project. Their needs must all be accounted for.

All of this can be accomplished with the technology we have today, but the cost would be astronomical.

Now I will respond to all the pots that happened while I wrote this long-ass post.

This problem has in fact been solved already.

For an actual colony, and not just an exploration mission, there would need to be at least hundreds of people sent to create a stable gene pool. There wouldn't be much elbow room, though, so thorough psychological examinations of the participants would be necessary to weed out potential problems.

Can that be done currently? I think there are still issues with waking the people back up.

A colony would have to take fairly advanced medical equipment with them. Remember, we aren't going to be sending colonists on a space shuttle, more like a large, mobile space station.

Daily exercise can help with that. People have spent months in space and managed to recover, although they were weak when first returning to Earth. Also, Martian gravity is slightly lower, so the weakness would not effect them as much there. But that is a major problem.

The ship would have to be nearly a mile in diameter or the rotation would cause constant motion sickness. While the ship might end up being this large, rotating such a mass would be very cost-prohibitive.

The discussion is useless without qualifications.

What's the purpose of doing this? Just to do it? If so, then of course the answer is yes.

If you want to start a profitable and sustainable colony on the moon or Mars, then no. The colony would be completely dependent on Earth's resources.

For a while it would be dependent. And a truly self-sustaining colony is probably beyond our ability now. But we could make one that could last for several years on its own while waiting for the next supply ship from Earth.

It could be done with today's technology, but it will be much cheaper when robots are sufficiently advanced to do all the pathfinding and basic building work.

I agree. It will be probably be much easier in the future. But having a colony out there, even if only as far as the moon, would provide an incentive to produce the technology that will make it easier, meaning we would reach that stage faster than if we simply sit on Earth and wait until it will be a piece of cake.

If we need to design a new ship to accomplish this then in fact we do not have the technology to colonize another planet.
The technology we lack is the of "colonization ships", so to speak.

Of course, I'm being a smart-ass by nitpicking on the definition of "Today's Technology". Perhaps we should make that into "Had we started working on it right now, could we colonize another planet within n years?" Possibly adding "Assuming an unlimited budget."

Also, do we get an unlimited budget for such an imaginary project? Or is financial viability a consideration as well?

Financial viability is one of the major stumbling blocks for such a project, so it should be considered. But the main discussion is about whether we could do it, not whether we will, so for the purpose of discussing our ability to do it we should consider our budget nearly unlimited. The project would be impossible if the world economy collapsed halfway through because all our money was being sent to Mars, so our budget is limited to the maximum that all countries combined could commit to the project while still maintain their economies. A real world budget would be much lower, with probably just the U.S. and a few other nations contributing.

I think the discussion is whether we have the technology to build such a ship and the colony itself. The whole thread would be a moot point if we already had such things.

AFAIK, nausea is caused more by free-fall (aka null-g, aka space w/out gravity) than by spinning anything. Motion sickness is caused by a disagreement between visually and kinesthetically perceived motion (such as reading in a car, when by looking at your book you are causing visually perceived motion to be nil, but you can still feel the bumps on the road). This would not be present in a spinning spaceship because the only kinesthetic perception would be gravity-like outward pressure, and there is no obligation to show people the outside.

With a smaller craft the spin would have to be much faster to maintain a reasonable amount of pseudo-gravity. The speed of this spin would cause the disagreement between visually and kinesthetically perceived motion

That's why I said I was just being a smart-ass, and that perhaps we should consider it more of a "Can it be done in n years?" or "Had we started it x years ago could we accomplish it y years from now?" (where n,x,y are relatively small numbers)

Having read "Red Mars" I'd say we probably aren't too far off, but probably not close enough either (Haven't read the sequels, I only found out they exists by searching for the English name for Red Mars right now)

Like Matthew said, this discussion is pointless without qualification. If for example the US decided to switch all military spending to colonization spending we could fast track the Ares V and start launching 150+ ton payloads into orbit on a monthly basis.

A year of that and you could put some significant hardware and infrastructure on Mars ready for the pathfinders (first explorers) to use.

Likewise, the Russians could start building and flying Energia's and do the same thing.

Using todays technology we could build a pusher-plate Orion type rocket and fly to Jupiter/Saturn in a couple of months, Mars in a couple of weeks.

Somebody just has to be willing to pay for it.

I have plans for a gravity unit in my book that uses that same concept. The key is the angel. Another key is the gyroscope.

we currently have the technology to do every thing but the indevisal components are scattered. we need to put them together to farm the units we need.

Getting to another planet is one thing. Sustaining ourselves there is another thing. I'm curious if we could actually recycle chemicals efficiently enough to provide ourselves with an unlimited amount of oxygen, food, water, and energy/fuel. With our current technology could we theoretically survive in space without Earth? With our current technology could be practically survive in space without Earth?

I remember watching a special on one of the discovery-like channels where they said that it wasn't practical yet. Theoretically, we are close, but in practical terms we still have a long way to go.

Mars does have free carbon dioxide in its atmosphere. this could be sued with photosynthesizing plants to create more oxygen. I'm not sure if converting carbon dioxide to oxygen can currently be done through artificial processes.

Oh, WOW! The first few posts in this thread reminded me of an old DOS game called Moonbase. I haven't played the game in probably over 15 years. It was about developing a base, searching for materials and becoming financially independent of Earth at some point (among other things).
http://www.allegro.cc/files/attachment/594837
http://www.allegro.cc/files/attachment/594838
http://www.allegro.cc/files/attachment/594839
http://www.allegro.cc/files/attachment/594840

someone else mentioned this earlier...the book "Red Mars" by Kim Stanley Robinson gives in my opinion a good impression of the technology needed to colonize Mars.

The only motion our bodies kinesthetically perceive is acceleration. This we feel as force pushing us opposite the direction of acceleration. When the spaceship starts turning, you would feel some force opposite the direction of angular acceleration, but thereafter you would feel only the centrifugal mock gravity. Because we feel this all the time, it will not trigger motion sickness, and visually perceived motion would be nil (assuming you are motionless relative to the spaceship). This is the same force we feel when we are standing still on Earth. What's the problem?

I'm not sure how it works exactly, but i think it has something to do with the coriolis effect

I second (or third) the book Red Mars. It uses 'magic' technology in a few places, but overal its a very good read.

I think its possible to get people onto Mars right now but the costs (money and risk to human life) are so high no one will. Making it sustainable is something else entirely.

From my knowledge, the Coriolis effect is weak enough that it will be overridden everywhere except very near the center by centrifugal force.

If there was a spinning module in the ship for gravity, I think this organ would let us know we are dizzy... But I don't know if this applies in space where there is no gravity.

I think that the labyrinth only responds to spin in which you are near the center. Otherwise, it will simply be overridden by centrifugal force. Overall, to settle this debate we really just need to try it. Has anyone tried building a spin-for-gravity space station or ship?

Keep in mind that the occupants shouldn't feel like they are spinning. In theory, they should feel like they are standing on Earth. The only contradiction to this would be changes to the ship's velocity (direction, speed).

** EDIT **

Thinking in more detail I guess jumping would be bad... And what would hold you to the "floor"...?

Quoting someone else: We haven't even explored all the abysses found in oceans, and we already want to go to space? Way to waste money. Therefore, it is not possible to do that unless it is for scientific purposes (it is not cost effective). What happened with that Biosphere thing, where some guys were going to stay in a sphere in the middle of a desert for 7 years?

Why wouldn't we want to go to space? There is no livable space at the bottoms of oceans; in space there is, or could be with some effort.

Space won't be viable in at least another 100 years. It was just a silly goal put by the US and the USSR during the Cold War.

The angel will. havet you bin in a Gravitron before

http://en.wikipedia.org/wiki/Gravitron

edit:

http://upload.wikimedia.org/wikipedia/en/1/11/Gravitron2.jpg

in this pic more then 9.2gs of force is produced

What "angel"?

At least we had something to compete over that didn't involve blowing each other up.

The only practical reason I can see today for actually making self-sustaining colonies is because of over-population problems here on Earth. And our current technology is not up to handling the scale of colonization that would be required to handle over-population. But if we tried on a small scale it would give us valuable experience for when we are ready to try for a practical reason.

In other words, the only reason (other than scientific inquiry) for attempting to build a self-sustaining colony today is to give us experience for when we want or need to build one in the future.

Or, to get humans into another foothold so that if/when the Earth blows itself up, we can repopulate.

That too.

Earth could hold over twice the amount of current inhabitants. But that would force companies to relinquish certain aspects of their business (like decreasing prices, giving away unused lands, preparing non-inhabitable lands like deserts, etc). And even when these problems were evident, we have no means of moving enough people out of the Earth to another planet to make a difference.

We should be able to mobilize thousands from Earth to our new home in hours, not 20 or 25 people in a month.

The only way it makes sense is because Space is free, and the only borders will be created when companies colonize them. No country can claim ownership of space... but companies can.

It's like PHALANAX in UFO: Alien Invasion. Setting up an agency to prepare for an alien invasion sure sounded stupid back in the 1960s, but by 2084 everyone rejoices that PHALANAX already came up with all the manuals/guides/instructions/strategies/tactics required to set up an initial defence against the aliens (and eventually will be able to defeat them).

Good analogy.

We know that overpopulation will probably become an issue at some point, unless something changes soon. Why not prepare for it when we have the time?

When did this become a discussion about should we do it instead of could we do it?

Again, then we should concentrate on transporting thousands of people at the same time instead of trying to setup a house in the Moon. Not worth the trouble putting buildings there if every travel takes a week and can only transport 30 guys at the same time.

That's what I've been saying. We need a ship that can carry at least several hundred, if not more, people to the colony site.

Yet we are concentrating in finding out what is after Pluto. What else? Void!

You gotta crawl before you walk and walk before you run.

As far as we know.* It's not uncommon for scientists to discover new things even here on Earth. It isn't far fetched for them to have missed something in space. Besides that, it's not like everyone is focussed on that... There are individuals and teams all over the world dedicated to various aspects of the universe we inhabit.

Um, there actually is more stuff out there you know. Its just a little too far and a little too cold inorder to see it properly. Last I heard, they expect to find one or two planet sized objects out past pluto in the "near" future.

tldr -- some people are into fantasy football, but I guess this is what "does-it" for us geeks, isn't it?

edit: also, from what I read -- someone seems to be complaining that jumping wouldn't work in simulated gravity -- which isn't true at all -- your horizontal velocity doesn't change while jumping vertically. -- Throw a ball upwards in a moving car -- it will come straight back down to you -- even though it's moving forward at 60 mph and you didn't throw it forward...

No -- it was actually kind of scarry when the USSR beat us into space (we beat them to the moon, which was silly, but into space was not silly), because at that point they had technology to launch intercontental missles at us.

Nobody's complaining... I questioned it... At the time, I confused myself... It makes sense again.

This is where coriolis force comes into play. If the radius of the spinning is too small, and thus the rate of rotation too high, then a ball will not come straight down at all. Ball games will still be possible on space habitats, but the weird gravity will give the home team the advantage.

Not if they play on a field perpendicular to the direction of rotation.

The home team will still have the advantage, because they know how the ball spins sideways.

Surely even in American Rugby they change ends at half time.

America has rugby?

Yes, it's similar to Rugby League except you are allowed to forward pass and you keep your space-suit on

Keep in mind that I know nothing about how Rugby is played.

It was invented at Rugby School (where Tom Brown was tortured in the eponymous novel) by a scrophulous youth who flagrantly flouted the Laws Of Association Football by picking the ball up and carrying it over the opposing team's goal line. The youth was of course immediately whipped, tattooed and exiled to The Colonies, but the Games Masters were intrigued by the potential carnage if all the boys were made to fight hand-to-hand for possession of the ball, and so they devised a game with an egg-shaped ball, involving martial arts and police-dog training, which has spawned a variety of derivatives that are enjoyed by the worldwide sado-masochistic community today.

And to honour that, the American version of the game was called football?

We must. My current female-fix, who happens to be a physics major, oddly enough, is on UW's rugby team -- I'm not sure if we have a national league or even a college league, I just know that UW has a women's rugby team.

Small radius centrifugal force can give you motion sickness due to the high rate of rotation required. The fluid in the vestibular system (used to detect falling over) will rotate along with the space station and all is well. But if you rotate your head to look 90 degrees away, the rotation is out of phase, and you get sick just like you'd stopped spinning to get dizzy.

I have lost all faith in humanity. Again. Someone suggested Saturn to me as a possible colonization site. She did not realize Saturn is a gas giant. I cry for her.

i have lost faith in humans a long time ago.

http://www.freemars.org/jeff/planets/planets5.htm

The real stepping stone to space is anti-gravity. Without it, nothing is really feasible.

I would think some form of enertial dampers would be more usefull. You can always just create a long ship and spin it end over end, and deal with any dizyness

From the known laws of physics, anti gravity is impossible. What if, say, gravity could be manipulated? Slingshot effect for ships in orbit, all kinds of things.

Still pretty Sci-fi. What we need is an archology.