New Mars Forums

This is a really important point.  Even a successful flag & footprints mission evaporates risk like fog in full sunlight.  Right now naysayers can raise ridiculous possibilities.  "But how can you know their bones won't turn to jello?"  Afterwards, risk discussions can be brought down to Earth ... so to speak 

I think Antius is right and it'll come down to economics.  So then the question changes to something even more illdefined than terraforming: how will companies profit from space?  Under what conditions does terraforming save them money?

When considered this way I think Ceres has a relatively high probability of being terraformed.  It is small enough that terraforming won't take forever (like Mars) and it is in the asteroid belt which will be a source of low delta-v (relative to, say, Earth-Moon L1) material for ... well, a long long time.  Zubrin's low gravity advantage argument for Mars applies 10 fold for Ceres, and Ceres itself is a source of a valuable commodity - low delta-v water.

Even if Mars is technically easiest to terraform, it may have a difficult time funding it.

It depends on the specific impulse of the propulsion system, but for CH4/O2 it's about 400% to low orbit and 600% to escape.  This is a bit misleading because while methane will probably be the Martian fuel of choice for some time to come, terrestrial manufacturing has a wider range of choices, e.g., nuclear-based options.

See Zubrin's ...

The Economic Viability of Mars Colonization
http://www.cbqc.net/mars/docs/m_econom.pdf

Are there some good online references for space mirror projects? 

I looked but couldn't find much.  A couple of ideas at halfbakery

http://www.halfbakery.com/idea/Eliminate_20Night
http://www.halfbakery.com/idea/Space_20 … ar_20sands

Some climate related geoengineering.

There are some interesting ideas in there.  Light at nighttime, heat in winter, concentrated solar for industrial or energy generation, seems like weather control might be in there somewhere - may be hurricane intensity reduction as a first project.

Do the mirrors/shades have to be at GEO?  How low mass can we make them?  What's a low cost control method (mirrors don't have to move much to "turn off" but they still have to move)?  What's a high accuracy control method ("pinpoint" delivery of energy)?  If it were used to melt tar sands/oil shale would the local climate be unduly disturbed?  10 km radius?  100 km radius?

And it's located right in the middle of the asteroid belt.

It's low gravity and rotation period mean that geostationary orbit is at ~250km above the surface.  That in turn means a no-taper space elevator would only need a material with a tensile strength/density ratio of 4000 Pa m^3 kg-1.  Which is practically anything.  Almost any metal could be used with a safety factor of 10 (i.e., 1000% over critical).

Hi Impulseman, these are some very wonderful visualizations - thank you for making them.  It is hypercool that you are thinking about Hadley cells and the like.  Unfortunately I think you are a little ahead of the curve here    I'll offer my guesses, but I think you need a Mars global climate model to get good answers.

I think the thicker atmosphere (x2.6) and lower gravity (x1/2.6) balance each other out to leave the lower solar radiance (~45%) as the main thing we have to account for when looking at the poleward rotation.  I think less driving energy means the loops will be larger and slower.  So the Ferrel cell would be smaller if it exists at all (may be push the lower latitude from 30 to 35 or 40).  Even on Earth the Ferrel cell is more of a mixing area than a well defined rotation.  Slower poleward rotation means lower Coriolis effect (Mars rotates at about the same rate as Earth), so the "trade winds" and the "jet streams" will be slower as well - so bigger loops in the East-West direction as well.

If you are going to get into circulation models, you might also want to think about ocean currents, which have a fairly large effect on climate on Earth.

If your coding skills are up to it, EdGCM ( http://edgcm.columbia.edu/ ) has code and basic maps for Mars ( http://dev.edgcm.columbia.edu/browser/MarsGCM ) but you would have to alter things for the terraformed world.

You're right up to date with our knowledge of Phobos' composition - i.e., we don't know much.  There was a Russian probe that was about to find out more but just as we were about to get good data ... it died.

So best guess – there isn’t much metal, but there is carbon, silcates, organics and water.  So you’ve got the basics for carbon nanotubes (CNTs) and associated CNT-fiber composites.  This stuff is way better than metals and well within your time horizon, see …

Superthread, 100 times stronger than steel
http://www.lanl.gov/news/index.php/fuse … 2006-08-31

Phobos’ main value is that it is out of the gravity well.  It’s what 10e15 kg?  So at a generous $1000/kg (the space shuttle costs 10 times that) it’s value is $10e18 – millions of trillions or something. 

Water is needed by asteroid miners and other moon bases.  Water can be broken down into hydrogen and oxygen for rocket fuel.  And, at very first, water can just be heated and used as reaction mass to deorbit craft from low Earth orbit (LEO).  That saves LEO companies a lot of money because they don’t have to ship up the deorbiting fuel from the surface at $1000/kg.

How to get the volatiles out?  Just heat the ore a couple of hundred degrees – may be just with largish solar parabolic reflectors – see http://en.wikipedia.org/wiki/Solar_furnace – remember you’ve got low gravity though, so you’ll have some sort of capturing harvester – may be as simple as a big bag.

If you use the specifier

site:newmars.com

in google, e.g.,

mars direct site:newmars.com

then you'll get a whole lot more results.

So are you one of those people?  If not, then why are you dismissing the copious peer reviewed science I have presented to you?  The information in the Discovery Channel program you watched probably came from the NGRIP guys.  If you actually bother to read the article they say: we realized on our previous dig that past a certain depth the ice was all folded up and was giving us bad readings, so we moved to a new location where we could bore deeper. 

They’ve taken better measurements.  The state of scientific knowledge has changed.  Why can’t you accept that?  Because you’ve joined the Church of the Ecological Apocalypse.  Things can only get worse, they can never get better.  Any information that contradicts immediate overwhelming eco-catastrophe is funded by oil companies, anything vomited out by the Club of Rome – no matter how implausible – is scripture.  Where is the science in this?  For some reason you _want_ the apocalypse, just like fundamentalist Christians _want_ their version.  It isn’t healthy.

So many of my friends do this: “So what if climate models have holes you could drive a truck through?  There are lots of good reasons to end oil dependency.” 

I agree that there are lots of good reasons to end oil dependency.  So why not use those reasons?  Why pervert science and conjure immanent climate catastrophe?  Science is our only defense against slavery to superstition.  It’s too important not to try and stop it being hijacked by ideologues.

Good, be skeptical.  But be a little bit skeptical about what the commercial media and the climate alarmists are feeding you as well.   This may help ...

Understanding Common Climate Claims
R. Lindzen, Alfred P. Sloan Professor of Atmospheric Sciences, MIT
http://www.geocraft.com/WVFossils/Refer … Claims.pdf

Thanks, I missed that one.  Lava tubes could be quite large on Mars.  Now if only we can find one with a convenient underground frozen lake of water nearby 

Moonquakes
http://science.nasa.gov/headlines/y2006 … quakes.htm

induced thermally and gravitationally (tidal stresses from Earth and Sun).

I think "thick-shell" habitats have the same problems in the long term - the costs of constantly guarding against vacuum - but they definitely have inherent safety advantages over thin-shells, and I admit they may be the most economical solution for a long time (hundreds of years).

It's also an open question as to whether we can adapt to microgravity.  I personally imagine that it can only be health positive, but it could be that some essential aspect of our biology requires gravity at a certain level.  If that's the case, then the role of aeroliths is probably limited to holiday resorts.