Retreat Mars

[Ecthy]

Plus, it has less gravity and no decent atmosphere. Have you never watched Babylon 5?

[Ned]

Originally posted by RedFred
Ned, cosmic radiation would affect people exactly like any other kind of radiation. Mars has a crap magnetic field; iirc the earth's is great because of all the iron in its core and the rotation speed.

Dagletti, I don't understand what you mean by a Lagrange point between Earth and Mars. If such a thing existed how could it be stable?

Volatile lighter elements which would normally be found in a planet's atmosphere have largely leaked out to space already as a result of Mar's lower gravitational field. Would you really want to hydrate the atmosphere at such a huge effort if the water would be lost eventually?

Merely living on Mars is a huge enough challenge; terraforming it, even if possible, is quite a bit less probable.

Redfred, If I understand you correctly, terraforming makes no sense at all without a magnetic field. So the first step would be to restart Mars magnetic field. However, as far as I know, we haven't even dreamed the technology to do that yet, right?

[Sarxis]

I have seen B5.

So I guess pissing into the wind on Mars would make any man seem Herculean?

[Ethelred]

Redfred, If I understand you correctly, terraforming makes no sense at all without a magnetic field.

The Earths magnectic field changes over time. It goes to reverses about every 50,000 years and that means it not only gets much weaker that it is now but that it actually goes to zero. Its the ozone layer that gives us much of our protection.

So the first step would be to restart Mars magnetic field. However, as far as I know, we haven't even dreamed the technology to do that yet, right?

There is no way to do that. The Earths magnetic field is caused by the movement of liquid iron within the Earth not because the Earth is rotating. Mars doesn't have a liquid core anymore so it can never have a field of its own again. To create one artificialy would be quite a task. I suppose it could be done with some E.E Smith or John W. Cambell type superscience project. Fusion reactors in orbit generating a current in a ionized gas for instance.

[Korpo]

It may not be possible to get carbon quickly, but oxygen is highly available since Mars surface is made up of a lot of iron oxide (like rust, therefore red).. a plant or algae splitting off oxygen of this soil is imaginable and surely designable.. grow enough of it, and you get an atmosphere factory, that should be able enrich Mars atmosphere faster than it is leering off into space.. oxygen may be not as much of a greenhouse gas as hydrogen, but it would "suffice"

[Ethelred]

The oxygen that is release by life is a waste product from conversion of CO2 to carbohydrates and proteins and all that other stuff that life needs carbon for. Without enough CO2 then life would not be releasing the oxygen that is in it.

Now a factory could produce oxygen from iron oxide with enough power. On earth the first oxygen that life released was absorbed by non-oxidized iron. This is when most of the Earth iron ore was created as the iron salts were oxidized and became insoluble in water. The early Earth atmosphere apparently had a very high CO2 content as Venus although likely not that high.

[Ned]

OK, So even if we mastered the technologies, how long would it take? Hours, decades, centuries, millenian, or eras?

[Goingonit]

Originally posted by Ned
Redfred, What happens to people exposed to cosmic radiation?

Cosmic radiation isn't nearly as harmful as it's cracked up to be, and farther out (ie Mars) it would be even less severe.

[Velociryx]

Awesome thread! I'm avidly interested in seeing us colonize other worlds.

In my mind though, we'd need to start MUCH more simply. Terraforming is a great long-term idea, but there are just so many unknowns that will remain largely unknown until we reach the point where we've got people on site studying the problem from that side of the telescope.

What I'd really, truly like to see is something like this:

1) Complete the international space station and use it as our first "stellar port" - we could station a shuttle or two there permanantly and use the station as a holding area for equipment headed for a lunar base (perhaps even doing pre-assembly work in the station).

2) Establish a lunar base and begin examining the moon's resource base. Might be able to get a mining and/or a low-gravity production plant up and running to put the base on a paying basis.

3) Using what we learned from the first two, extend our reach to Mars

As to setups, the bases would need to be fully enclosed (imagine a "greenhouse" as was mentioned earlier, but the interesting thing here is that we've now got some experience in doing that....the Biosphere projects proved that we can create a self sustaining environment right now, with today's technologies and monitoring equipment.

Once the staff was in place, they could begin experimenting with introducing various algae into the Martian environment, and studying the exact effects of the wimpy magnetic field on that planet, and we could plan from there, based on their findings.

-=Vel=-

[RedFred]

Great suggestions Vel, and good to see you again online ol' buddy.

A couple of links, first of all one for Ethelred who seemed to be suggesting that the earth's magnetic field was not that significant in reducing cosmic radiation. While it is true that the atmosphere is a huge help in reducing cosmic radiation (living in Vancouver will get you less exposure than living in Denver; cancer rates for high altitude populations are higher), it is far from the only factor, here is a primer on the Van Allen radiation belt which slows up and even traps a lot of radiation:

http://www-spof.gsfc.nasa.gov/Education/Iradbelt.html

Another link is for Goingonit who seemed to be suggesting that cosmic radiation was not that big a deal in any case. This link suggests that even the cosmic radiation received over the relatively short several days exposure that the Apollo astronauts received was a serious concern:

http://lsda.jsc.nasa.gov/books/apollo/S2ch3.htm

If you see any edits, it means I've messed up the links again and I have attempted to fix them.

Another barrier to a quick Martian flight, and one that is hopefully far easily solvable, is one of navigation. The Apollo astronauts had an experimental system to do their own navagation which never worked well enough. All course corrections came from Mission Control. This would be less effective given the distance to Mars.

Ned, I wouldn't want to hazard a guess on when the first manned flight to Mars will occur, let alone a serious colonization effort. I did such an exercise as a schoolboy back in 1969 and failed miserably. Then I thought we would be there by the 1990s.

I think Vel's idea about greater habitation of earth orbiting space stations, a presence on the Moon are more likely intermediate steps.

[Velociryx]

Hiya Uncle Red! And thanks! I mostly lurk and post in the CB forums these days, but now and again a thread will draw me out...and this one's pretty fantastic!

IMO, there are some fantastic industrial applications to be had in space....opportunities for mining and low/zero-g manufacturing techniques are well worth looking into, and as flights become commercially viable, I think it will be the drive to new resource sources (and new potential resource points) that will send us into space, and I firmly believe that if we start small, and start off by looking at the adventure into space as a commercial one (find ways of making it pay for itself...makes it more likely to get funded in the first place), then we could see ourselves with a thriving off-world presence in my lifetime.

-=Vel=-

[Velociryx]

PS: Did I just sound like Nwabudike Morgan there, or what?

-=Vel=-

[Ned]

Red Fred and Vel, if cosmic radiation is a concern on the Martian planet surface, how are astronauts orbiting the earth or traveling between earth and Mars protected from cosmic radiation? Is the metal skin of the spacecraft enough?

[Velociryx]

It's my understanding that the earth's magnetic shield extends quite some distance around the earth, such that standard orbits fall within its boundaries. Even still, I would imagine being closer to the periphery of the magnetic field would increase exposure, but I'd imagine that for the relatively short duration flights and space walks our astronauts make, the level of the shielding provided by the walls of the craft and their space suits are prolly sufficient.

For longer duration stays (ie- a permanantly manned space station), we'd need to make sure that there was sufficient shielding from that. And of course, it's a valid point that as we move further from the sun (Mars), it would take relatively less shielding to accomplish the same level of safety. Mind you, I'm not a science guy, but that's my understanding of it.

-=Vel=-
(licks his chops in anticipation of one day seeing thriving mining operations in the asteroid belt....YUMMMM)

[RedFred]

Yes, you are sounding like Morgan, Vel; but better that than Yang who would probably be waxing poetic about ODPs...


Ned, Vel is quite right. The magnetic field around the earth does extend to standard earth orbit but it weakens the further away from the earth you get.

You've got solar radiation which is unpredictable and gets extremely high during sunspots. The closer to the sun you are the more you get nailed. You also need to worry about cosmic radiation from other stars and such which doesn't decrease with distance from the sun and isn't as highly variable.

The only ways I know of reducing radiation are with materials or magnetic fields. You can dig deep into Mars and put a lot of material between you and the radiation source. Or you can use extremely dense metals as shielding (from near the bottom of the periodic chart, like lead.) I think a decent magnetic radiation shield is a whole new technology we haven't gotten to yet. But that shouldn't stop us. They invented tons of cool stuff for the Apollo missions.