MarsDirect - - how much does it cost?

Bill White · 2004-01-05 10:52:02

This essay at the SpaceReview repeats the cost of "humans to Mars" as being $400 - $500 billion dollars.

How widespread is this belief?

Is Zubrin's estimate of $50 billion (very round figures) remotely accurate?

clark · 2004-01-05 11:01:01

From the article:

Based on previous NASA estimates, such a mission would cost more than half a trillion dollars.

This would be from Bush Sr. time in office and his call for a Manned Mars Mission. Nasa came back with a 500 billion dollar price tag for some Battle Star Galictica ship.

I think no one is quite sure what the actual cost would be becuase so much depends on the make-up of the supposed mission.

How many people? How long? How fast? Acceptable risk levels? How many abort options, and when and where, do you want? What is the overall mission architecture- follow-up missions, etc.

500 billion is too much, IMO (but you could always spend it!), and 50 billion is too low, IMO.

A mission to Mars will at the very least cost as much, if not more, than ISS.

So about 100-200 billion.

Palomar · 2004-01-05 11:10:36

*Page 3 of _The Case for Mars_ (published 1996) says (I won't quote verbatim...copyright issues) a rough estimate for MD would be approximately $20 billion towards the development of the required hardware. Each individual mission would cost roughly $2 billion (after ships and equipment are in production).

Dr. Z says that amount of money, if spent over a 10-year period, represents about 7% of current civilian and military space budgets combined.

--Cindy

RobertDyck · 2004-01-05 13:57:14

The 90-day report that NASA produced after president George Bush Sr. asked NASA to go to Mars in 1989 had a price tag of $450 billion. That included a space station, permanent Moon base, Moon mines for fuel, Earth orbit fuel depot, dual keel on the space station to build the interplanetary ship, and a separate orbital facility to check out the spaceship before it heads to Mars. The ship itself would have been a giant one with nuclear engines and on-board greenhouse, but only half the crew would land on Mars and they would only spend 2 weeks there.

Robert Zubrin said in his testamony before congress that the NASA budget guys estimated Mars Direct at $30 billion, including development and 7 missions to Mars. In his book he said $20 billion. NASA's design reference mission (DRM) had a price estimate of $55 billion, but it would have carried 6 astronauts for each mission instead of 4.

The half trillion dollar claim comes from people who want to kill anything in space. So, the price for the war in Iraq is $88 billion and counting. Hmmm.

GCNRevenger · 2004-01-05 23:02:48

Bush I's big megaspaceplan was not to put man on Mars. It was to put man in space as far as Mars, hence called the Space Exploration Initiative, and not "Mars Indirect".

Dr. Zubrin's estimates are almost comically low considering the fantastic cost that the ISS is chalking up and Shuttle's inflated price, and that isn't for hardware with a performance that nobody has yet matched and has to work the first time. No, there will need to be one more technological generation before travel outside Cis-Lunar space is really practical. Higher max temp materials, lighter weight composits, advanced nuclear systems (GCNR or light-weight VASIMR), higher reliability rockets & LSS systems, maybe a Scramjet "Shuttle III," and most of all skill in building spaceships.

RobertDyck · 2004-01-06 01:33:53

Bush I's big megaspaceplan was not to put man on Mars. It was to put man in space as far as Mars, hence called the Space Exploration Initiative, and not "Mars Indirect".
Dr. Zubrin's estimates are almost comically low considering the fantastic cost that the ISS is chalking up and Shuttle's inflated price, and that isn't for hardware with a performance that nobody has yet matched and has to work the first time. No, there will need to be one more technological generation before travel outside Cis-Lunar space is really practical. Higher max temp materials, lighter weight composits, advanced nuclear systems (GCNR or light-weight VASIMR), higher reliability rockets & LSS systems, maybe a Scramjet "Shuttle III," and most of all skill in building spaceships.

Ah, I mentioned "nuclear engines" with the implication that they were too much, and GCNRevenger comes out to argue. Well, I repeat that nuclear engines would be nice but a price tag of $450 billion is not going to happen. Mars Direct used existing technology in 1991, not "hardware with a performance that nobody has yet matched".

In fact, I contacted the Russian company after I read in Robert Zubrin's book that the most cost effective way to send humans to Mars was using the Russian launch vehicle Energia, I asked if anyone had contacted the manufacturer. When I didn't get a response, I contacted RSC Energia. Their answer was that it is available. After some digging I discovered they had maintained 3 launch vehicles to lift their space shuttle, but they were handed over to Kazakhstan on January 1, 2000. The Kazakhs were looking for money, so they were interested in selling. Robert Zubrin said Mars Direct would take 2 Aries rockets for a single mission to Mars, or 3 Energia launch vehicles. Well, we had 3 tested, proven launch vehicles waiting for someone to buy them. Unfortunately the vehicle assembly building collapsed on them on May 12, 2002. However, I also contacted KBKhA and confirmed the RD-0120 engines are still available. Bottom line, the launch vehicle is available and proven; there is no "hardware with a performance that nobody has yet matched".

Aerocapture: Mars Pathfinder and the latest Mars Exploration Rovers, Spirit and Destiny, use direct entry. Do you really think there's a difference between direct entry and aerocapture?

ISPP: NASA already gave Robert Zubrin's company a contract to build a brass board version of the equipment to prove it works. Then they gave his company another contract to produce benzene instead of methane; it has a 1:45 fuel production ratio instead of 1:18. True, no one has proven a benzene fuelled rocket engine yet, but methane engines have operated for years.

Life Support: see the system on ISS and the Sabatier Reactor that the Johnson Space Center already demonstrated.

Lithium-Aluminum alloy, also known as Weldalite: it's what the external tank of Space Shuttle has been made from since start of construction of ISS.

Any more hardware in Mars Direct you would like to claim "nobody has yet matched"? My argument is that nuclear engines are nice, but not necessary. Lighter weight composites are nice, but we have really good ones now. If we keep saying we "need one more technological generation" we will always be waiting and never accomplish anything. We're ready now. Progress is already stagnating, if we don't do something now we will never move ahead.

Or should I challenge Americans to get off their collective ass? The U.S. government seams to respond to that. Here's the challenge: the U.S. hasn't made any progress except in personal computers, producing better porn, and dropping better bombs. This lack of progress looks like the U.S. is no longer capable of economic development. Its economy will stagnate and stall while other industrial countries slowly catch up and surpass it. Those countries will colonize space and reap the vast riches it contains. Europe has a very slow plan to place humans on Mars, but they are making progress. If the U.S. continues to sit on its hands, either Europe or China will pass it. The Canadian Space Agency is already partnered with both NASA and ESA, they will be part of whichever plan gets there first. There GCNRevenger; is that challenging enough to convince you we can and need to go now?

Rxke · 2004-01-06 01:42:59

The Soviets had plans to go to Mars in the mid eighties, so...

Knowing them, then, it would've taken them what, 10-15 years?
I think it's possible today. And not a flag and bootprints single mission, too..

RobS · 2004-01-06 01:55:18

I quite agree with Robert; we have plenty of technology right now. The big lack is a portable 3-tonne nuke for surface power. For about two billion per two years, we can fly manned missions, and the system should be developed for the same or less than ISS.

-- RobS

robcwillis · 2004-01-06 19:52:22

Taylor Dinerman appears commited to exploiting every lie and distortion imagineable to promote his own political ends. I invite all Mars advocates to start sending him the hate mail he so richly deserves.

GCNRevenger · 2004-01-06 22:03:45

Here we go again... No, its not, it doesn't in the slighest change my mind, but first a word about Bush I's SEI:

Bush I's nuclear-rocket powerd "Battlestar Galactica" Mars ship was a monster by any measure of the term; huge crew, hydroponics, multiple landers or fuel for them, loads of extra equipment, possibly rotating sections, and the biggie, enough fuel for a return trip via an Opposition orbital transit, which is a severe mass penalty when you are using low-temperature solid core NTR nuclear rockets as proposed. The $450Bn also included money to build at least one large space station to assemble the thing and a multitude of 20-50 ton launches to ferry the componets to orbit, and if memory serves, for a 2nd space station and a Moon base might be part of that figure?... $$$

Guess what? An advanced nuclear rocket tailored for Mars won't require that sort of undertaking, when better computer-modeling of physical extremes in nuclear engines and higher temperature resistant materials to build them with, which is not that far off. A GCNR engine is easily tripple the power of solid-core NTR rockets, perhaps as much as an order of magnetude more in a refined form: this alone turns Bush's nuclear battleship into somthing much smaller; every gram of fuel mass saved yeilds a nearly exponential decrease in total mass. Build the ship for the sole purpose of going to Mars efficently, no orbital assembly platform at all beyond perhaps a collapseable truss with a robot arm and a few solar pannels, and the cost falls even more. Finally, build the Ares SDV in some configuration, and build the pieces of the Mars ship to ride on it; lowering the number of launches needed by a factor of five or six with the improved SRBs. No no, a well designed and well managed GCNR/VASIMR Mars ship will not cost several hundred billion dollars, which is simply an impractical sum, any which way.

Well of course thats what the Russians told you that about the Energia, they have their pride to protect and old otherwise useless rockets to sell (which we would do too in the same position...). If you look at it from a mass-to-Mars point of view right now, then yes they are correct that at the moment it is the least expensive way. That doesn't mean its cheap(!), it only means its less bad and there are only enough for one mission without rebuilding the factory! They still do not carry enough mass for more than flags&footprints: 25 tons to Mars every 2.5 years each including lander is peanuts for anything long or short term, ISS would require five times that to do anything useful; you would be lucky to include a decent rover in the Mars Direct strategy... It really is that bad, especially when you consider that it can't withstand any weight-creep.

Areocapture and ballistic entry are absolutely two distinctly different orbital maneuvers, they are not in the slightest comparable: ballistic entry requires less trajectory accuracy, is straight through the atmosphere hence little concern for its maximum altitude or upper thickness, and is much easier to design in self-correcting aerodynamics. Aerocapture on the other hand, requires extreme trajectory accuracy; you are aiming for just the very outside rim of the atmosphere at exactly the right attitude and velocity with little margin for error: you must bleed off only just enough velocity, unlike entry where you want to get rid of all of it, hence is a vastly more exacting parameter. I doubt that self-correcting aerodynamics would be possible either. The Martian atmosphere, since it is so thin and the gravity weak, varies in maximum altitude often, especially with the solar wind hitting it, introducing another extremely dangerous variable... Real orbital aerocapture of the type you are thinking of has ever been accomplished, and you want to risk lives to it? Cargo maybe, but people no, propulsive capture offers obvious system safety benefits.

In order to do anything more than take pictures of flag-waving astronauts kicking up red sand, you will need a reuseable means of landing on Mars from Mars orbit... this is where the advanced composit materials come in, so that a "Martian DC-X" can be built that consumes a minimum of fuel per flight round trip, since it will likly be chemically powerd. Advanced high-temp materials for the insides of a GCNR or VASIMR engine, and maybe for a Scramjet SSTO cargo ferry, would substantially reduce risk and expense.

I won't go into the other safety or logistical failings due to MD's low-tech approach that you can read about in other threads, but I will summerize: no abort option, dangerously long transit times (6 months is long. Too long.), low practical flight rate, rare launch windows, landers for every payload, little mass margin for radiation shielding, no reuseability, and the best part is little room for improvement at all: MD is the plateu for today's tech.

I never said that we don't have the technology to go put man on Mars right now: we can build cryogenic engines, small nuclear reactors, inflatable habs, that much Dr. Zubrin is right about... what we don't have is suitable hardware on the shelf, which will be long/hard/expensive to become a flight-ready system, not that it is beyond current technology. HOWEVER, we do NOT have the technology to go for keeps and to stay, our rockets are still too weak, too unreliable, and too heavy to do more than plant a flag and make a little attempt to look for bugs... There is a threshold before exo-lunar travel becomes cheap and safe enough to really go out there, and current tech obviously cannot reach it. Wishes and foolish hopes to the contrary won't make that launch window any larger or the little MD "space cottage" any bigger.

Better to spend the money and time on developing advanced propulsion technology and building the SDV/Ares for tomorrow, instead of wasting it with a dead-end Mars sight-seeing trip what what is possible today.

RobertDyck · 2004-01-07 10:49:59

Oh, how tiring. GNCRevenger, the Mars Society exists to get a humans to Mars mission NOW. Not in 60 years, or 30 years, or another generation; now! As long as you argue that a mission to Mars must be held hostage to your particular pet technology, you will never be accepted. Perhaps you would be happier participating at www.nuclearspace.com where the entire focus is nuclear technology in space. Here our goal is a mission to Mars within our generation.

I see you only half read my last post regarding Russian rockets. The 3 Energia launch vehicles stored at building #112 were available from January 1, 2000, through May 12, 2002. On May 12, 2002, the roof collapsed destroying all three launch vehicles, and the Buran orbiter. Although I have confirmed that new RD-0120 engines are still available, and the strap-on booster is the first stage of a Zenit rocket so it's still in production, the fuel tanks of the Energia core stage are not. The factory would have to be rebuilt. Of course we could convert the American shuttle to a Shuttle Derived Vehicle; that would be just as good providing the contractors don't try to gouge the American taxpayer.

Aerocapture has been available for a while now. It was tried with Mars Climate Orbiter, but someone made a metric conversion error for the altitude. Such an error does not mean the technology is fundamentally unsafe. NASA hasn't used aerocapture since, demonstrating they have a glass jaw. Part of the point of Dan Golden's ?faster, cheaper, better? philosophy was that failures will happen so send many small, relatively inexpensive probes; if one fails you have others. NASA and congress have still been panicking over every single failure. To make the technology safe for human travel will require many unmanned probes to use it. That means use aerocapture now, for very orbiter that goes to Mars, and keep using it until failures just don't happen. I doubt another metric conversion error will ever happen.

Advanced composite materials already exist. We have graphite fibre epoxy composites that are very strong and light weight. An aerospace engineer at Lockheed-Martin has told me they have a liquid oxygen (LOX) compatible all-composite fuel tank. It already exists.

Mars Direct, with its mission architecture of landing everything on the surface does include a 14 month surface stay. That is definitely long enough to do real science and construction. You can do a lot more than flag waving in 14 months; in fact 14 months of flag waving would get very boring very quickly. MD does have abort capability; perhaps you didn't read the part about free-return.

However, I have already advocated a mission architecture with a reusable Earth orbit to Mars orbit spacecraft. That can be done with chemical propulsion with the option to replace the engine section with a nuclear engine when it comes available. Initially we would use expendable landers so the landers themselves can be dismantled for construction material for the base. After the base has been in operation for a few years, the Mars lander would be replaced with a reusable shuttle. That can only happen after a fuel factory and storage depot is operational on Mars surface. Since I argued for the Mars ascent vehicle to be an expendable stage for Trans-Earth Injection, the reusable Mars ascent vehicle can only be used when you also have a means to refuel the orbit-to-orbit spacecraft; either from Mars or one of its moons.

The bottom line is that we will never get anywhere if all we do is sit still with our proverbial thumb stick up or ass. We need to get it started now. Let's not get the cart before the horse. We need a manned mission to Mars to build a permanent base on Mars now, and we can follow that with all the pretty improvements to make on-going operations less expensive. We do need to design to permit these upgrades, but we have already seen those developments will never happen if we don't have a need for them. We need to create the manned base on Mars now to create that need. Spin-offs will include technology for asteroid mining, lunar telescopes, and low cost access to orbit such as a Scramjet SSTO, and an orbital space hotel for space tourism. But we have to create the need and start the process NOW.

Josh Cryer · 2004-01-07 13:01:30

Very well said Robert. Very well said...

clark · 2004-01-07 15:23:23

What if we changed the argument from, "It will only cost this muc to send people to Mars" to, "How much are we willing to pay, and support, for sending people to Mars".

"How much it costs" is like trying to sell a used car.

"How much can we afford" changes it ever so slightly, but it assumes an interest to begin with. I think there is an argument to be made that enough people would, or do support such a thing. This board is but one example. This provides a base to figure out what kind of mission can be put together.

Don't try to sell someone a car with dubious value, find out how much someone is willing to pay for a car of dubious value.

Just a thought.

Palomar · 2004-01-07 15:56:05

Robert Zubrin said in his testimony before congress that the NASA budget guys estimated Mars Direct at $30 billion, including development and 7 missions to Mars. In his book he said $20 billion. NASA's design reference mission (DRM) had a price estimate of $55 billion, but it would have carried 6 astronauts for each mission instead of 4.
The half trillion dollar claim comes from people who want to kill anything in space. So, the price for the war in Iraq is $88 billion and counting. Hmmm.

*Right. And as I pointed out in my initial post to this thread, in conjunction with the the 1996 (book) figure: "Dr. Z says that amount of money, if spent over a 10-year period, represents about 7% of current civilian and military space budgets combined."

If Dr. Z's estimates are correct, then the program is absolutely "do-able" and we -can- certainly afford this (allowing for comparable adjustments in GNP and other from 1996 to 2004; and again recalling that now [2003-2004] the "going" price is $30 billion -- 8 years after the book was published).

Mars Direct, over a 10-year period of time (based on the 1996 figure), makes up a paltry 7% of the civilian and military space budgets then combined. Robert, do you know what approximately the percentage would be today?

--Cindy

RobertDyck · 2004-01-07 17:54:46

Robert, do you know what approximately the percentage would be today?

According to the Congressional Budget Office, the total discretionary spending budget authority for defense for 2003 is $455 billion, and the outlays for defense are $407 billion. I'm not sure what the difference is, I hope they don't add. The discretionary spending for Homeland Security for defense has a budget authority of $12 billion, and outlay of $11 billion. If we take just the budget authority for defense for discretionary spending and Homeland Security, but leave out military pensions, that adds up to $467 billion. According to the NASA HQ Budget office the budget for 2003 is $15 billion, excluding federal retirees.

All that adds up to $482 billion. If $30 billion is spread over 10 years it will only be 0.62% of that. Of course that's the total military budget, not just the military space budget. If you only include NASA's budget, but average the annual increases from 2003 through 2007 to project it through 2012, then add all that up over the 10 years, it is 17.634%; but that doesn't include military space. I'm afraid I don't know the military space budget.

clark · 2004-01-07 18:00:02

Military space budget is largely secret, so exact amounts are hard to get... until years later. Right now, it's at 21 billion for just military space. I think I saw a projection of 28 billion by 2008 or so.

RobertDyck · 2004-01-07 20:30:59

Military space budget is largely secret, so exact amounts are hard to get... until years later. Right now, it's at 21 billion for just military space. I think I saw a projection of 28 billion by 2008 or so.

Ok, a $7 billion increase over 5 years; then projecting to 2012 that would be $33.6 billion. Calculating the total for 2003 through 2012, and adding that to the total for NASA you get 6.945%; that should be represented as 2 significant figures since the figures Clark provided only have that many, but we are also estimating into the future so we should round off to one fewer digit. That rounds to 7%, the same figure Cindy quoted.

Ad Astra · 2004-01-07 21:56:03

If Mars Direct were implemented with realistic assessments of the risk involved, more money would need to be spent on additional missions. After all, the first manned Apollo flight didn't land on the moon; the hardware had to be put through its paces in realistic and increasingly difficult situations.

I propose a test regimen for the Mars Direct hardware. First, the booster has to be tested unmanned (even if it is Energia, because the quality control needs to be ascertained.) Then humans should test the hab hardware and artificial gravity in earth orbit. Finally, a Mars flyby similar to Zubrin's proposed "Athena" mission would wring out the bugs in the hab and allow astronauts to perform useful science with remote controlled rovers.

The reason why Zubrin omits these operational tests probably has more to do with time than cost. He expects the first ERV launch to take place within eight years of program start. A more cautious program would delay this launch until the hab was fully tested (the first ERV launch is essentially a test, as Mars Direct can be aborted if a flaw is discovered in the ERV hardware after it reaches Mars.)

Somebody also brought up the issue of aerocapture vs. direct entry at Mars. The issue with direct entry is that the forces would be too great on the weakened crew. If a direct entry was attempted, it would require a biconic-shaped lander that made a lifting entry.

Bill White · 2004-01-07 22:53:28

Ad Astra - where does your opinion fall concerning the cost of MarsDirect.

Closer to $50 billion (even I can't buy Zubrin's $20 billion figure) or closer to $250 billion.

RobS · 2004-01-08 01:30:10

There's an article at Space.com or Spacedaily.com that I read yesterday that relates to this discussion of aerocapture. It said the course of Spirit was so precise they were managing the velocity to within millimeters per second, and as a result it hit the Martian atmosphere within 200 meters of its intended entry point! And they didn't even need the last two course corrections. They did reprogram Spirit slightly to change its parachute deployment time by a few seconds because of the Martian dust storm going on right now.

This is with one spacecraft in Mars orbit to forecast the atmospheric conditions. Imagine if there were two or three and that they were used in the navigational process. Under those circumstances aerocapture would be completely safe and a spacecraft could be put into the atmosphere within tens of meters of where it had to be. So I conclude that arguments against aerocapture are emotionally based, not scientifically based.

As for referring to Mars Direct as a flags and footprints operation, this seems intentionally misleading and belittling. If one felt that two launches every opposition was not quite enough mass for a four-crew mission, three launches certainly would be; and as I show in Mars-24, if you have a four-tonne, 400 kilowatt solar electric vehicle in Earth orbit, an EELV can launch 5 tonnes of xenon and 19 tonnes of other stuff and at least half of the 19 tonnes can be landed on Mars (if one uses hydrogen and oxygen fuel from the moon, one can land about 13 tonnes per 24 launched into orbit). So for another $200 million or so, you can send a cargo lander with extras.

If every opposition one landed 50 tonnes of stuff on Mars, in five oppositions that's 250 tonnes, and that is quite a lot. One can build up substantial capacity.

Now, admittedly, with a really nice gas-core nuclear engine one could rip out to Mars with a lot more stuff. But there are three "buts" to this idea:

1. It is not clear any US government can overcome the emotional opposition to such an engine. Perhaps GCNRevenger should move to China and hope it never has a democratic revolution.

2. The technology for such an engine could be developed in a ten year crash program, but that simply isn't going to happen, so MAYBE we're looking at 2050 or later before such an engine can get serious political and technological support.

3. The best way to justify such a program for Mars colonization is to start with something like Mars Direct, get people on Mars, and build up the need for more. NO ONE is talking about starting Mars landings with the goal of colonization. I don't see how colonization can be justified given the current political realities in just about any country in the world. It's not how politicians think.

-- RobS

Palomar · 2004-01-08 06:33:07

Ad Astra - where does your opinion fall concerning the cost of MarsDirect.
Closer to $50 billion (even I can't buy Zubrin's $20 billion figure) or closer to $250 billion.

*Well...that's a mighty wide-ranging figure there.

I've read Ad Astra's replies and Rob S too.

My main draw for Mars Direct has been its relatively low cost (lower than the figures NASA quotes).

--Cindy

clark · 2004-01-08 10:43:55

How much does the 'in-stui' or whatever the heck it is cost? (the thing that goes before the humans to make the fuel for the return trip)

How big is this stuff?

How would it land on Mars?

Do we really feel confident in our ability to get things to Mars, and then land them on Mars, where we want?

We just sent a 400 pound rover, and now we are waiting an extra week beyond the expected warm-up for a deflated balloon to be retracted.

I've played craps before, but I wouldn't want to roll the dice on this kind of bet.

Palomar · 2004-01-08 11:01:56

*While caution is healthy and honest questioning is a good thing, I have to admit I'm amused by nay-sayers who persist in hanging around a forum (for years) which promotes something they seem to disapprove of to begin with. Oh well.

Anyway, the Mars Direct crew will have an advantage the Spirit doesn't have: Automatic human decision-making, manipulation, flexibility and control...in REAL TIME (as opposed to 10-minute transmission delays between Earth and Mars, as is the current situation with the rovers).

Dr. Z addresses a lot of the more nail-biting aspects of Mars Direct in chapter 4 of _The Case for Mars_, entitled "Getting There."

It certainly would be of benefit to actually READ the material you are questioning before deciding it's a bad idea or you might not want to stake a gamble on it, no? :laugh:

Being INFORMED certainly lends credibility to arguments, pro or con. Persons who haven't read material they are attempting to debate defeat themselves. Right?

--Cindy

clark · 2004-01-08 11:14:29

*While caution is healthy and honest questioning is a good thing, I have to admit I'm amused by nay-sayers who persist in hanging around a forum (for years) which promotes something they seem to disapprove of to begin with. Oh well.
Anyway, the Mars Direct crew will have an advantage the Spirit doesn't have: Automatic human decision-making, manipulation, flexibility and control.

LOL! :laugh:

I read this, and thought, hey, ecrasez_l_infame might be talking about me! Took a deep breath, read again, and realized, no, she couldn't be possibly be talking about me.

You see, I asked about the 'in-stui', which preceeds the Human Mission, so no humans woyuld be there to make last minute course changes. It would be like the rovers are now.

And we haven't been doing exactly well with those, at least not overall, which was my point.

Dr. Z addresses a lot of the more nail-biting aspects of Mars Direct in chapter 4 of _The Case for Mars_, entitled "Getting There."
It certainly would be of benefit to actually READ the material you are questioning before deciding it's a bad idea or you might not want to stake a gamble on it, no?

So, if you have the Zubrin Bible in front of you, which some of us do not, could you, or perhaps a friendly person, give us clues on how the 'in-stui' fuel production is supposed to occur, so we can have a good idea of how this might happen?

Unless of course any have problems with simple questions. You know, the way most humans learn.

Bill White · 2004-01-08 11:38:05

Try this which is what happens when you type:

"Mars Direct in situ fuel production" and click the belief that you are lucky.

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