The Case for Mars

[Earl Snake-Hips Tucker]

One of NASA's long-range goals is to land people on Mars.

Because of the orbits of Earth and Mars, there are only two practical mission profiles: one in which they would stay a month or so, the other in which they would stay 18 months.

Every time I've seen someone talk about what they would ultimately like to do, it's always the 18-month plan. The one-month plan is practically not even being considered.

Doesn't this sound like it would greatly compound the risks of an already very risky mission?

Why not send C#3,Palidors,etc!

[tomndebb]

I would guess that it would be hard to justify the expense if they only spent a month on the planet. This isn't a moon shot where a couple of weeks leads to a couple of hours surface time. This is years just for the travel. I doubt that they could get unpacked in a month.

------------------
Tom~

[Satan]

Yeah, what he said...

------------------
Yer pal,
Satan

[Narile]

Also, many current plans call for a 'two stage' deployment. (I can't remember the actual term used.) Where you have rocket A landing on Mars well before anyone living sets foot there using rocket B. Rocket A would carry the fuel (or make it) and equipment to return to Earth, and Rocket B would carry the people there. If you are going to use this sort of system to do the job, the eighteen month stay over makes a certain amount of sense cost wise. Also, because of the time it takes to travel and return from mars, such missions would want to maximize amount of data gathered.

------------------
>>Being Chaotic Evil means never having to say your sorry....unless the other guy is bigger than you.<<

---The dragon observes

[Boris B]

Wait a minute here, are you guys sure it would take years to get to Mars? How many?

[Polycarp]

Boris, IIRC, a doubly-tangent free-fall orbit (i.e., one that just touches both Earth's orbit at Earth's position on it and Mar's orbit at Mars's position on it) is 15 months minimum.

[tomndebb]

My memory was that a Mars trip (one-way) was 15 to 18 months, and could be longer, depending on the relative positions of Mars and Earth. (I had never seen the info presented on the site with the 259 day estimate.) 15-18 months gives 2 1/2 to 3 years round trip.

------------------
Tom~

[Ukulele Ike]

Or substantially LESS time if they use Cavorite.

[danielnsmith]

Mjollnir,

Where would the human race be if no one ever took a chance. The whole idea of space exploration is to find places to put our population because we bred like rabbits.

I would rather take a risk in space than live an accident free life on Earth.

As far as I'm concerned, the risk and cost are justified by what we would learn from it. (How to travel between planets.)

[Therealbubba]

We have to send robots there first to see if it's worth exploring any further. We can get virtually the same data with robots for a fraction of the cost. Let's make sure it's worth risking human lives before we take the big plunge.

Therealbubba

[Akatsukami]

Therealbubba insists:We have to send robots there first to see if it's worth exploring any further. We can get virtually the same data with robots for a fraction of the cost. Let's make sure it's worth risking human lives before we take the big plunge.
The problem is, the machines called "robots" have about the intelligence and behavioral flexibility of a simple bacterium. If anything more is called for (as it surely will be), actual human beings will be called for.

------------------
"Kings die, and leave their crowns to their sons. Shmuel HaKatan took all the treasures in the world, and went away."

[tracer]

Akatsukami wrote:

The problem is, the machines called "robots" have about the intelligence and behavioral flexibility of a simple bacterium.

1) So do most Astronauts.

2) I believe we are now capable of building robots with the intellect and flexibility of an entire flea, not just a simple bacterium.

------------------
The truth, as always, is more complicated than that.

[tracer]

Danielnsmith wrote:

The whole idea of space exploration is to find places to put our population because we bred like rabbits.

I disagree with this assessment. Even if we can establish colonies on the Moon and/or Mars, and develop dirt-cheap launch vehicles to send people there, the maximum rate at which we could send people to other planets wouldn't begin to put a dent in Earth's population. If finding more elbow room is your goal, you can colonize Antarctica or the oceans much faster and cheaper than you can colonize another world.

The motivation for European exploration in the Renaissance had nothing to do with European overcrowding and everything to do with finding new sources of raw materials, goods, and slaves. Manned space exploration in the 20th century has been primarily fueled by national pride. If manned space exploration is to continue in anything more than a token capacity, there has to be an economic incentive.

------------------
The truth, as always, is more complicated than that.

[Therealbubba]

OK, say we skip the robot thing and spend a trillion bucks to send a few humans to Mars to wonder at the twin moons and knock around a few golfballs. Then there is a disaster. That will be the end of NASA and space exploration. We're not even sure if we have the technology to manufacture rocket fuel in space without bankrupting the planet.

We probably can't terraform Mars, definately not in our lifetimes, so what's the point? There are plenty of heavenly bodies for us to exploit nearer to earth. The moon, ateroids and comets are alot cheaper to get to, I think.

If the robots show evidence of life or something else interesting on Mars, let's pack up and head out. But let's wait and see. It's not like Mars is going anywhere.

Therealbubba

[kaylasdad99]

Tracer:
Hmmm, slaves, huh? That might be a worthwhile prize to bring back. Paldors? Contestant #3? We'll defer to your wisdom on this one <chuckle, snort>. How likely are we to find an exploitable indigenous population on Mars. It would be nice to BE the alien invaders for a change.
As for you, danielnsmith, Mjollnir did not seem to be averse to _taking_ the risks. The way I read his post, he felt that if we ARE going to take the risk (which should be substantially the same regardless of how long the visit), we should stick around for a while and get some real work done.
And as for those of you who are arguing the point about sending robots, I have this to ask you: Haven't we already sent several robots to Mars? I find it a touch ironic that this particular angle should be getting this type of attention right now. After all, the last robot we did send to Mars crashed and burned because somebody's right hand didn't know what somebody else's left hand was doing (what with the English Engineering system of measurement being less than compatible with the metric system, at least when proper conversion factors are omitted). In a letter to the editor of the Los Angeles Times yesterday, I read somebody's horror-struck question, "what if that mission had been MANNED?" Well, IMO, the astronauts would have been in a position to fly by the seat of their pants and rescue an expensive set of hardware.

------------------
Time to change the signature line; my cover's been blown . . .

[StrTrkr777]

I think they meant the design of a craft to go to Mars would take years. Or maybe I misunderstood the statement.

Jeffery

[Boris B]

http://hyperion.advanced.org/12145/text/summiss.htm

The above site estimates the time for the trip from Earth to Mars to be 259 days. I don't know how their assumptions differ from the 15-month assumption. It's a very interesting site, anyway, with lots of neat stuff about various types of engine that I don't understand.

[Polycarp]

OK, I didn't RC. Sorry!

[Therealbubba]

I am not aware of any failed robot missions to Mars. The satelite failure was human error, not robot error. Dead robots are a learning experience, dead astronauts are a reason to stop exploring space.

I have nothing against going to Mars, as long there's a good reason. What's so wrong with taking our time, improving the technology, sending some robots to scout it out? Isn't NASA planning a robot that goes to Mars, scoops up some dirt, and brings it back here? Wait and see what data that bring us first.

Therealbubba

Certainly, we should delay going to Mars until we've gathered as much data robotically as we can; but if the day ever comes when a robot is the functional and true intellectual equivalent of a well-trained, creative human being -- well, we'll probably be to busy putting down the revolt of our robot slaves to be colonizing Mars.

Wasn't 'Cavorite' what they used to explore the moon? They couldn't carry enough of anything to make it all the way to Mars; anyway, I think Lionel Jefferies is dead. Good reference to a Hammer film, though.

Why would we want to 'colonize' an asteroid or coment when Mars is obviously much more 'terraformable' and has a nice, stable orbit that doesn't bring its surface temperature within spitting difference of absolute zero for most of the time?

I've always wondered why we don't exploit Earth-crossing asteroids for a 'free' ride to Mars. Using the two phase approach someone has previously mentioned, we can send a robot ship ahead with all necessary supplies and fuel-generators. There are literally hundreds (maybe thousands, at last count I believe I heard about 2100) of such
asteroids that have already been detected, with more being found every week. If you stop to think that even in the Space Shuttle, we've demonstrated the ability to fly for millions of miles, the sphere of available space around the Earth is huge, so the asteroid doesn't even necessarily have to come all that close.

So, as the asteroid passes close to the Earth on the way out (we having brilliantly plotted its future course to show it coming close to Mars), and we send out a mission to hitch a ride. One advantage: if we miss on the hitch, the ship's course can be plotted to bring it back to Earth fairly fast. Assuming we catch it, we have a nice, big asteroid to do productive research on while the trip takes place, instead of a lot of people floating around looking out the window getting depressed and homesick as the Earth fades to the rear, and finding various ways to twiddle their thumbs until Mars comes up. Also, we have a nice asteroid to mine for various substances like nickel, iron, molecular substances of all kinds.

Then, we just have to be damn sure there'll be an available asteroid to ride home on; or else, that the one-way trip home will be a lot easier to make -- as always, life support will be the big stumbling block. Could be, though, that the asteroid itself will help solve that problem.

Also, the single best reason to colonize the moon or Mars is to assure the survival of the species in the event of a planet-killer asteroid strike.

[Polycarp]

DIF...cavils and comments on your asteroid post:

I was under the impression that the origin of Cavorite as a fictional anti-gravity-producing substance was from a H.G. Wells story back around the turn of the (20th) century. Don't remember seeing it in any film use.

Someone (Arthur C. Clarke?) had pooh-poohed the idea of "hitching a ride on a comet" (with "asteroid" interchangeable with "comet" for these purposes, though I think we're all clear on the real differences). The general idea was that since a space vehicle able to rendesvous with a comet/asteroid headed for Mars orbit was already on a free-fall orbit that would permit the rendesvous, it was already on (or nearly so) a free-fall orbit that would take it to Mars, and nothing would be gained by making the rendesvous, since the delta-V needed to make the rendesvous would be (virtually) the same as to make the flight without the rendesvous.

However, you have made one clear and obvious point that had, so far as I know, escaped Clarke(?) and everybody that has repeated that argument since: that on such a long trip, there would be both scientific, resource-availability, and human-values reasons for using a passing asteroid as a "base in transit." Nice work!

Polycarp, I'll reply more after I get back from lunch. I knew about the Wells' reference to Cavorite. They made a movie of it back around 1964 (IIRC), with Edward Judd, Lionel Jefferies, and (IIRC) Martha Hyer. First Men in the Moon, IIRC. Should be easy to find on the IMDB.

[Ukulele Ike]

Polycarp and DIF are BOTH right...Cavorite was an anti-gravity substance, an invention of a British scientist named Cavor (duh) in H.G. Well's novel THE FIRST MEN IN THE MOON. It was filmed in 1964, not particularly well, with Lionel Jeffries playing the Cavor role and a coupla never-weres as the Romantic Interest.

-- Uke, miffed at mixing the moon and Mars.

[Ukulele Ike]

Damn. Sorry for the redundancies, DIF. I was so excited about answering PolyC that I skimmed right over your last post.

[Sam Stone]

Hitching a ride on an asteroid isn't going to do you any good. You have the mistaken idea that position is important. It's really not. It's all about the energy required to translate from one orbit to another. So you burn a bunch of fuel to match orbits with the asteroid, then it gets to Mars and you detach... and you're still in the asteroid's orbit. Now you have to burn a bunch of fuel to get into Mars orbit. Unless the asteroid's orbit is already the optimum transfer orbit to Mars, this will cost you more fuel than just flying there on your own.

Whaaat the fuck was thaaa--????!!

Damn, Ike, thought I'd just had the first SDMB UFO sighting, and it just turns out to be you!

Polycarp:Someone (Arthur C. Clarke?) had pooh-poohed the idea of "hitching a ride on a comet" . . . since a space vehicle able to rendesvous with a comet . . .headed for Mars . . . was already on (or nearly so) a free-fall orbit that would take it to Mars . . .nothing would be gained by making the rendesvous. . .

Hope you won't mind the redact.

I apologize, Poly, for having somewhat misled you with words like "hitch a ride". What I have in mind would involve intersecting orbits which would bring a mission vehicle close to the asteroid briefly, but not entail matching full velocity with it. I was trying to think of an analog situation over lunch, and I think I hit on one, if you'll pardon the obvious differences.

Imagine a kid on skates standing at the crest of a hill on a paved street. By himself, with a bit of an assist from gravity, he can get going about 10 mph. But he wants to latch onto the city bus, approaching at 25 mph. He gets himself going and, as the bus rushes past, he makes a very carefully planned throw with a grappling hook that lands perfectly inside the bus's bumper. Now, if that was all, when the tether on the hook played out, the kid would jerked off his feet, signifying mission failure.

But (and it may be a big but, but someone else will have to do the finer math) let's suppose that, instead of just rope, the kid has a very elastic bungee cord instead. Without trying to draw the analogy too perfectly, as the cord plays out, the kid readies himself, and when the jerk comes, the cord begins pulling him, but only gradually, so that the kid can adjust to the speed and begins accelerating. Gradually, the bungee cord recoils, pulling him forward faster and faster, but never so fast that he loses balance. Also, once he's going, the kid begins reeling in the cord until he's up with the bus's bumper and can grab on.

You see where I'm going? The mission ship's orbit would be a big loop that would bring it back to Earth if the ship failed to catch the asteroid. The ship throws out a huge aramid fiber net in space in the path of the asteroid -- let's say the asteroid is as big as 10-story building. Let's also say the cord on the net is initially 10 kilometers long, but can stretch to 200 before stopping. So those aboard the ship have time to adjust to the admittedly sudden change in direction because the instantaneous delta-V is relatively small; it'd probably still be in the range of 6-7 G, but bearable.

On the way out, assuming the asteroid is the correct type, the crew mines the asteroid for nickel and iron, using a solar furnace. The nickel they attach a rocket to, and put it in a parking orbit over Mars. As they approach, they plant an explosive which separates them, along with a big chunk of the rock, from the main body of the asteroid. As final approach nears, they break the chunk of rock up and start throwing it off AFAP to the front, reducing their momentum and reducing the amount of aerobraking they'll eventually need to do.

Cavils?

dhanson: nope, for the reasons just given.

[Polycarp]

Sounds to me like it would work, and save on needed fuel, in the unlikely event of having an asteroid on the appropriate orbit. I say unlikely because it is not enough to get from Earth to Mars' orbit, but to the particular point on that orbit occupied by a rather small red planet at the time.

[Therealbubba]

DIF....What I meant by exploiting other heavenly bodies was that we could get the basics (water) etc. from comets, asteroids etc. without having the expense of getting them into space.

Therealbubba

[Ukulele Ike]

Here I go dragging the science discussion back over to literature...humanities major, he humbly apologized.

This getting dragged off the planet on an asteroid is reminding me of the OTHER 19th century SF writer everyone knows, Jules Verne, and his novel HECTOR SERVADAC. Sometimes known in English as OFF ON A COMET.

A chunk of Earth gets ripped off by the tail of a passing comet, and the group of assorted Europeans left on board have to deal with the fact that they're now scooting all over the solar system. One of Verne's most virulently anti-Semitic novels, and also one where he gives free rein to his distaste for the Germans and the English.

Traveling around space on the tail of a comet? I sure as hell never understood the Science in THAT one.

------------------
Uke

[tracer]

Therealbubba wrote:

I am not aware of any failed robot missions to Mars. The satelite failure was human error, not robot error.

What about the Mars Observer mission a few years ago? That thing just plain QUIT on its way to Mars.

[Momotaro]

Robots are cheaper and becoming better at what they do. Also, there loss is not tragic like the loss of an astronaut. Colonizing Mars with robots will only make us build better robots.

------------------
Only humans commit inhuman acts.

Polycarp, I see what your saying; but are you really aware of just how freakin' many[i] of these things there really are? Also, a couple of things occurred to me after that last post. First (assuming a nickel-iron asteroid) the nickel would represent a fabulously valuable lure for further expeditions if it was left in Mars orbit. Perhaps even a robot mission would be sent just to attach a large enough rocket engine to the nodule to nudge it into a orbit toward the Earth (but, safely bypass the planet if no one made the catch). The iron tailings coming off could be formed into hollow cylinders or rings and shot out with an electric mass-driver. As far as getting to the 'particular point' you mentioned -- it occurred to me that, once the asteroid has been used to provide the delta-V necessary for shortening the trip to a few months, you really don't absolutely need it anymore. As long as Mars and the asteroid are heading in the same general direction, you just carefully pick the point you want to launch into the transfer orbit for rendezvous, using optimal values of fuel, etc.
========================================
Gotcher point, Bubba! One quibble -- I'm not sure how easy it would be to mine a comet for water. By the time it gets close in enough to Earth, it's also going to be so close to the Sun that it's going to be out-gassing like mad. But it just now occurred to me -- you might place an [i]opaque net in front of one, design it to wrap around the body (bolus?), and then, on its way out, have an explosive charge shatter some considerable 'nugget' of ice free and harvest that. As for an asteroid -- a robot miner similar to what I've described might do that, using a mass driver to send the nickel Earthward a lump at a time.
========================================
UkeIke: Did you ever see the early '60s movie with (IIRC)Sean McClory? Don't remember that much about it. I think I saw it with my brother, and we both thought it was absurb, even then.

[Ukulele Ike]

DIF: Wow! Four stars for YOU this afternoon! No, I'd never heard of it, never known that it had been attempted. Looked it up in IMDB just now: VALLEY OF THE DRAGONS, 1961. Maltin thinks about as much of it as you did.

------------------
Uke

[Therealbubba]

Tracer, missed that one. I stand corrected. Anyone know what happened? Was it a lander or an orbiter? Good thing there were not astronauts on board.

Therealbubba

My memory of the subsequent NASA investigation of the loss of the craft was their (tentative, and fated to remain so) guess was that a failure in a pressurized gas line necessary for control led to a loss of the craft as it approached Mars. And, of course, (as did this last mishap) the charge of "they're covering up the discovery of a Martian civilization!" on the part of fringe groups.

[tracer]

Therealbubba wrote:

Good thing there were not astronauts on board.

If the Mars Observer had been designed to carry astronauts, they would've (A) tested the spacecraft a LOT more thoroughly before sending it to Mars with people on board, and (B) had manual overrides which would have allowed the astronauts to pilot the spacecraft by hand.

Carl Sagan remarked that once you put human beings on board a spacecraft, that spacecraft's primary mission then automatically becomes one of returning the humans safely to the Earth. All other mission objectives immediately become secondary.

If one manned mission costs the same as 10 unmanned missions, and three of those unmanned missions fail, we're still ahead by a factor of 7-to-1 if we go the unmanned route.

------------------
Quick-N-Dirty Aviation: Trading altitude for airspeed since 1992.

[AWB]

I say we don't send manned missions to Mars until the US completely converts to Metric. :)

Seriously, I think these are the steps needed to get men to Mars:[list=1] Getting a viable space station going. Then, start setting up stations in solar orbits between Earth and Mars to act as resting points (ala the camps on the way to Mt. Everest's peak).
Developing a way to extract usable O2 from Martian soil. Depending on pre-tanked O2 would be too risky a venture.
Develop a propulsion system that isn't chemically driven. Some sort of solar sail or ionic propulsion would be ideal.
Contact the Martians to make sure our tourist visas are all in order. :)[/list=1]

[tracer]

AWB wrote:

Getting a viable space station going. Then, start setting up stations in solar orbits between Earth and Mars to act as resting points (ala the camps on the way to Mt. Everest's peak).

Stations in solar orbits between Earth and Mars won't work. The farther out from the sun you are, the more slowly you orbit it. The likelihood of a solar-orbiting "station" being right on the Earth-Mars trajectory at any one moment is tiny; the chance of being able to hit all of them en route is vanishingly small. Plus, even if your trajectory did manage to intersect an intervening station, you'd still be going way too fast when you reach it -- you'd have to waste energy (fuel) slowing down to dock with it, then waste more energy (fuel) speeding up again to get back on course for Mars.

Earth-orbiting space stations are seen as a useful taking-off point for deep space exploration, not because you can reload supplies from them, but because ALL deep-space missions start off as Earth-orbiting missions -- so you can use them as refueling stages or as places to build a spacecraft in Earth orbit. In low Earth orbit you start off with 17,500 miles per hour of delta-V on your side, and as Heinlein once remarked, "17,500 m.p.h. is half way to anywhere."

------------------
Quick-N-Dirty Aviation: Trading altitude for airspeed since 1992.

[tracer]

I think I could make a case for this thread being bumped out of the oblivion that all pre-2000 posts are in for.

Of course, my case for this thread would consist primarily of the fact that I saw Mars through my 12-1/2" reflecting telescope 2 nights ago, but still....

[Nuri]

Robots simply wouldn't do the job. They cannot feel textures well, and simply do not have the reasonings that is the super computer Human brain.

I attended a seminar over colonizing space, titled "Explore and Exploit" last march. Basically we have a fairly good amount of tech to get to Mars, and even considerations of where to land. There are still enviromental challenges to get over.

BTW, the seminar did talk about the extraction from soil and atmosphere, if I could find more of that in my notes. I would share. But they seem to have disappeared in the mix of school papers.

[Badtz Maru]

Um, if you can get into a position where you can land on a comet, you don't need the comet - you are already in it's orbit, I can't think of much to gain from attaching to it.

[Phobos]

Originally posted by Therealbubba
I am not aware of any failed robot missions to Mars. The satelite failure was human error, not robot error.


There are several failed robotic missions to Mars. The one you mentioned was a human error. Other mission losses are not 100% explained and could have been mechanical problems (or mechanical inadequacies).

http://www.seds.org/~spider/mars/mars-l.html

Mars 6 (USSR): Lander spacecraft; crashed on Mars on March 12, 1974.

Phobos 2 (USSR): Successfully reached Mars orbit on January 29, 1989, and returned data and photos of Mars and Phobos. During an approaching manoeuver to Phobos, the craft lost orientation due to computer defect, and suffered energy loss, which terminated the mission.

Mars Polar Lander (Nasa), former Mars Surveyor 1998 Lander. ...after reaching the surface of Mars, contact was never re-established. While the reason of this loss is not known, the most probable cause is that due to a programming fault, the craft turned off its rocket engines early and consequently crashed upon Mars' surface. The two microprobes, anyway hi-risk missions, also got lost due to unknown reasons.

But maybe you could debate that these were human errors.


Dead robots are a learning experience, dead astronauts are a reason to stop exploring space.


I disagree. Three astronauts have already died and yet we keep exploring (launch pad fire during Apollo era). Exploration of any frontier is dangerous and yet many people would happily volunteer to take the risk. Exploration is part of human nature, IMHO. Anyway, the extreme long-term survival of the human race (or whatever we call ourselves millions of years from now) depends on moving on to other worlds. In the shorter long-term (hundreds/thousands of years), our species would be safer if we didn't have all our eggs in one planetary basket. In current times, exploration is a source of challange and inspiration.


I have nothing against going to Mars, as long there's a good reason. What's so wrong with taking our time, improving the technology, sending some robots to scout it out? Isn't NASA planning a robot that goes to Mars, scoops up some dirt, and brings it back here? Wait and see what data that bring us first.


I agree with that. The only rush is my impatience to see these things happen in my lifetime. I already have to wait until about 2020 before anything reaches Pluto (http://www.planetary.org/html/news/articlearchive/headlines/2001/2plutoprops.html)! :)

[Phobos]

Originally posted by Therealbubba
Tracer, missed that one. I stand corrected. Anyone know what happened? Was it a lander or an orbiter? Good thing there were not astronauts on board.


From the same link I just provided...

1992 September 25, Titan IIIe-TOS
Mars Observer (Nasa): Reached Mars on August 21, 1993, and sent some TV images on approach. Contact was lost during its orbit insertion ignition; it may have been damaged, blewn up, or simply frozen after having lost orientation.

If astronauts were aboard, there could have been more options for saving the mission (e.g., manual controls).

[elucidator]

Is it really remotely credible to send a crew, even a crew of one, on a round trip mission of several years, with no possible option of resupply?

Robots. Only way for now. Don't need water, don't need food. Computers crash, people go crazy. That's a wash.

[Phobos]

Originally posted by elucidator
Is it really remotely credible to send a crew, even a crew of one, on a round trip mission of several years, with no possible option of resupply?


The Zubrin clan proposes first sending a robotic mission to set up a resupply camp (extract materials from Martian soil to create rocket fuel). Then each subsequent manned mission would add one section to a biosphere (i.e., leave part of their ship behind) and use that Martian fuel supply to return home. Eventually, you would have a self-sustaining colony on Mars once you added enough pieces to complete the biosphere puzzle.

[tracer]

I assume you meant to type "the Zubrin plan" not "the Zubrin clan". Unless they're feuding with another family. ;)

Incidentally, could this incremental-biosphere-building trick also work for a colony on the moon? (If for no other reason than that a flight to Mars is about 20-30 times longer than a flight to the moon.)

[hardcore]

tracer, I have the book Phobos is referring to, and oddly enough the title is the same as this thread, i.e. The Case for Mars. Great book by the way -- I highly recommend it for anyone interested in Mars exploration. In fact, I believe NASA has since adopted the general plan (with some minor modifications) as THE plan for going to Mars.

A key feature of the Zubrin plan is a "live off the land" approach. But it doesn't extract fuel from the soil. Instead, it arrives on Mars with the fuel tanks virtually empty, with just some "small" amount of H2 (say 6 tonnes), then begins reacting it with the CO2 in the atmosphere to produce CH4 and H2O. The H20 is further broken down into H2 and O2, and the H2 is recycled. More O2 is produced by splitting CO2 into CO and O2. The CH4 and the O2 is stored as rocket fuel for the return trip, with plenty left over to power combustion vehicles to explore the planet's surface.

The humans are not launched until the return vehicle has been fully fueled by this approach and small robots have verified a suitable landing site.

So you can see, this doesn't work for the Moon because of its lack of an atmosphere. One reason I like this plan so much, aside from the fact that it just makes sense, is its reliance on simple chemical engineering fundamentals, something a chemical engineer like myself can appreciate.