New Mars Forums

I don't know about that.  I'd much want more energy than I knew what to do with than as little as it reaching Titan.  With a hot world, all you have to do is put up a sun shade and wait a few years.  If you assume that we'll have the tech for massive mirrors, it follows that we'll have sun shades.  I'm willing to bet that the time to drop a temperature is a lot less than the time to raise one.

Even if they get fusion working, the He3 is still going to be finite so once they run out of that, Titan will be a dead world.  It may be a thousand years but it's still got an expiration date. 

I like the idea of a tether motor in Saturn's magnetosphere.  Is it strong enough to produce any meaningful amount of power?

I also like the idea of cracking the O2 out of the rocks for breathing and burning to make C02.  That's going to take a lot of energy though.  Remember that they're rocks.

Ultimately, if Titan is going to be terraformed in any sense of the word, at least portions of it will need to be above the freezing point of water.  That's necessary for agriculture as we know it.  Anything else would just amount to living in habs and farming in greenhouses.  You don't need to go to the trouble of terraforming to do that.

There were some posts on this on the Terraforming Venus topic.

It's got a magnetic field, metals and Mars-like gravity so those are some pluses.  Lots of incoming sunlight too.  Not much in the way of atmosphere and just a bit of water that we know of.  No fair posting about building rails around the globe and running a city along it in permanent sunset.  KSR already took that idea.  A sun shade of some kind is probably going to be a must.

Thoughts?

I've still got my money on using hydrogen to process the CO2 into water.  I'm all about making use of the local resources, not blasting them into space.  We'll settle the bet in a thousand years. 

Anyway, I had a thought about the sun shade.  I can't see how big Mylar sails are every going to be workable even if we nail down 0-g manufacture and processing asteroids.  Between them getting hit by micro-meteors and keeping them in place without crumpling up, they seem like nothing but trouble.

I mentioned using a big electromagnet or constellation of magnets at the L2 point to act as a shield for the incoming solar wind.  You could probably also disperse some charges particles in there and the field would hold them in place.  Deployment of the dust would be far easier than a Mylar sheet.  For a sun shield, it could just be graphite dust gotten locally.  For reflectors for Mars or somewhere needing a soletta, light dust or maybe aluminum could be used.  You don't get the complete surface area coverage that a Mylar sheet would give but it wouldn't take an act of God to deploy it.  This even sounds like something NASA could make a prototype of and test with today's tech.  Hell, we could probably send one over and start the terraforming process now while we spend the next 100 years getting off of Earth.  Not a bad head start.

Any thoughts?

The water vapor would need to be condensed.  At that point, you would need some kind of sun shade or dust in the atmosphere to block the incoming sunlight.  Once you get that big rain though, the albedo of the planet is going to rise with a lot of surface water and possibly ice dependong on how cool you make it.

If anyone's interested, I wrote a long entry in my blog about terraforming venus.  It does count on some abilities that we don't posess yet but doesn't all of this?

[http://redefine.dyndns.org/~zinthefe/bl … 00085.html]terraforming Venus

Hazer,

I never said that setting up the gauss rifle infrastructure would be easy.  This is terraforming remember, nothing's easy.  However, The Russians were able to land craft on the surface and they survived for a short time.  That was in the 70's and I'm not even sure they were designed to last more than an hour anyway.  I'm sure by the time anyone seriously starts considering terraforming Venus, the material science will have progressed to a point where digging robots could be sufficiently protected to last on the surface for a long time.  Hell, with the creative use of Mylar, aerogel and some other modern materials, I'm betting we could have a craft operate on the surface today for a long time.

I just had an idea for changing the length of the day on Venus.  I don't know how feasible this is so feel free to poke holes in it.

The basic idea is to use a series of rail guns beneath the surface to increase the angular velocity of the planet.  For rail gun information look here: [http://home.insightbb.com/~jmengel4/rai … intro.html]http://home.insightbb.com/~jmengel4/rai … intro.html

For example, say there are two such guns on opposing sides of the planet on the equator each pointing in the direction of the planet's rotation.  Given a source of power like the sun or some other power source you can harness on Venus, you can power the electromagnets needed in the guns. 

Then let's say you fire them both at the same instant.  You push the first slug toward the first magnet, it accelerates toward the magnet, hits it and sends the second slug to the second magnet with the speed it gained from the 1st magnet's pull.  That faster slug accelerates further toward the second magnet and this continues until the final slug.  At this point, the last slug has picked up quite a bit of momentum.

If that slug hits a pusher plate (and doesn't destroy it) it will transfer that impulse into the planet.  The slugs can fall back to their ground state with the magnets off and you can start again. The energy of the magnets is converted into angular velocity thus giving the planet a slightly faster spin.

Now you'd probably have to scale that up with tens of thousands of guns placed at different levels beneath the planet and keep it running for quite a while but I'm pretty sure it would make the world spin faster. 

I might have mixed up some physics terms but let me know how that sounds.  Combined with a dyson motor, it might convert all that unwanted solar energy into enough angular momentum to give it a 24 hour or longer day.  Besides, aren't humans supposed to be wired for a 36 hour day or something?

Stu,

You make a lot of good points.  You're right about finding life being a great catalyst for getting humans to Mars.  There's nothing I could wish more for.  My pessimism about Beagle?s fate is based on Mars? tendency to devour two thirds of missions sent to it.  While the instrumentation on Beagle is no doubt more advanced than on the Viking lander, it sound like the life detection method is similar:  heat up some dirt, oxidize it, see what chemicals come out.  Viking did that and the best answer we got back was ?maybe?.  I?m worried that if Beagle does find something interesting, that the best it?s going to give us is ?probably? and not a ?yes?.  For all any of us know, all the life on Mars is a kilometer deep.  I?ll give Beagle my best wishes but I?ve got my expectations set very, very low that it will find any positive signs of life.

On the water thing, I would say that finding water is almost as exciting as finding life.  If there is a large amount of water under the surface, it would mean that Martian colonization is possible.  Without it, the world is a lot more closed to us. 

So I?ve got high hopes for Beagle.  I?ve been checking the web ever since early Christmas day.  Water, life, I want them to find it all.

I'd rather be traveling up a space elevator from Earth.  A space elevator would be the fastest way to setteling space by far and would open up the solar system to anyone who cared to pay a few thousand dollars.

Should Robert Zubrin keep the combover or just embrace his baldness?

Hi,

I recently got up to date on some of the political activities going on regarding Mars exploration and the direction of NASA.  I?m referring specifically to the testimony of Zubrin and Huntress before the Senate Commerce Committee, Zubrin?s ?mobilization? of the Mars Society and the bill proposed by Nick Lampson from Texas.

There may very well be other things going on that I haven?t heard of but those two stand out.  I tried to post a story on Slashdot touching upon all these topics but it got rejected.  I think it was because I submitted it under the wrong category but I?m not sure.  In any case, I thought that Slashdot would be a good place to find people who would join in a letter writing campaign on the direction of NASA.

Here?s the article that I posted (sorry about all the raw html).  If anyone can think of a better way to word it please do so and try to submit it.  Or if you can think of some other outlet to a potential pro-Mars exploration audiance, post it here.  It seems to me that now is the time to act and the more help the better.

Robert Zubrin, president of Pioneer Astronautics and founder of the Mars Society has called for the mobilization of Mars exploration proponents to write their representatives on the future of post-Columbia NASA.  From his announcement: ?This debate will play out over the next six months, and the result could determine the future of the American space program in our generation. Now is the time when anyone who cherishes hopes for a spacefaring future for humanity must step forward and speak up.?  This is happening alongside the recent testimony Zubrin gave to the full Senate Commerce Committee on Oct 29th (audio files here and the .pdf) and the proposed Bill from Congressman Nick Lampson TX to restore Mars as a goal and put NASA on a schedule. Here are a few sample letters if you want to write your congressman.