Has Dr. Zubrin Addressed Mars Direct Objections? - A few questions?

GCNRevenger · 2004-11-29 21:56:02

Specifics? I think that there is not enough mass budgeted for radiation shielding on either vehicle, the reactor mass is pretty optimistic (see JIMO), the budget for the rovers is unrealistic, and both vehicles need to be physically bigger. I am also suspicous of the ERV reentry capsule and bascially every figure in the whole plan is cut close to the bone if its practical at all, with little margin. So, I think that alot of the science gear and extra equipment are probobly just going to be cut when the inevitible weight creep attacks or when Zubrin's estimates fall short.

But more then that, MarsDirect is designed with the wrong philosophy in mind: the launch vehicle dictates too many paramters about the vehicle and this ought to be the other way around, that you ought to match the vehicle to the launcher and not vice versa. Zubrin desperation in trying to make Shuttle Derived work in only two flights is foolish without the aid of a nuclear upper stage ala NASA DRM.

And frankly, Zubrin's feverish zealousness to get to Mars is a problem for MarsDirect, that the "red dust or bust" mindset is liable to cut corners or promise what can't likly be done to push the project.

Shaun Barrett · 2004-11-30 02:19:12

"And frankly, Columbus' feverish zealousness to get to the Indies is a problem for the 'Nina', 'Pinta' and 'Santa Maria', that the "Indies or bust" mindset is liable to cut corners or promise what can't likely be done to push the project."

I guess that throughout history, there have been the 'feverish zealots' of science and technology who appeared foolish and desperate to many of their contemporaries.
Maybe many of them were fools and desperadoes whose ideas came to nothing. But there were many others who were ostracised and ridiculed, who eventually became historical icons of science and discovery.

Dr. Z has enemies. Manned space exploration has powerful enemies. But I wish we had more people like Dr. Zubrin.
A little 'feverish zeal' for space exploration in governments all over the world would be a nice change.

Mark S · 2004-11-30 02:41:50

Zeal can be a good thing (as Zubrin explicitly says in "Case for Mars,") but I fear that the Mars Society could just become a cult made up of Zubrin's yes-men and lose sight of the larger goal: putting humans on Mars.

Mars Direct, as an intellectual exercise at creating a minimalist Mars Mission, was a tremendous step towards getting us to Mars. But while it should inspire better mission design than the Battlestar Galactica ship of old, we should not dogmatically adhere to it.

Zeal + In situ resource utilization + nuclear thermal rockets + closed loop life support + a realistic number of crew for the science mission + conjunction-class trajectory = a successful formula for putting humans on Mars.

GCNRevenger · 2004-11-30 08:43:48

But Christopher Columbus didn't build his ships

I didn't say that zeal wasn't a good thing, only that letting it influence mission design is an inherintly dangerous thing. What happens if the mass budget is a few tons over and everything is already cut down to the limit? Drop an inch of radiation shielding? Delete the drill and the heavier lab equipment? Reduce landing fuel reserve margin?

That sort of thing... if you were a rational engineer, you would obviously say "NO!," but if the zeal to get to Mars has you in its grip, you might be tempted to start making cuts that you shouldn't that will decrease the safety and gain of the mission.

Zubrin's zeal is admirable, and his plan while unworkable has put the world on the right mission arcitecture path, but cutting corners to make the mission fit on a quasi-exsisting booster with exsisting engines to save money is a terrible idea and is the wrong way to go about building a mission.

Another thing is, I think Zubrin is desperate to convince people that going to Mars is "no big deal," in which I think he is flat wrong. Going to Mars with a scientifically gainful mission will very much be a big deal, no matter how we get there.

Blind adherance to a plan that is pretty obviously not going to deliver on what it promises will help further the notion, which isn't helped by Zubrin's personality, that folks like in the MarSoc are not serious or competant about mission design.

I would think that the history of manned spaceflight being litterd with casulties due to corner cutting would convince you... Challenger (too cold for SRBs), Soyuz-1 (under developed, rushed to flight), the Apollo pad fire (under developed, construction corners cut), all of them share one thing in common that corners were cut.

John Creighton · 2004-11-30 09:09:05

There is too much money on the line to take too big a risk or cut too many corners. Forget Zeal think success.

BWhite · 2004-11-30 09:14:46

Zeal can be a good thing (as Zubrin explicitly says in "Case for Mars,") but I fear that the Mars Society could just become a cult made up of Zubrin's yes-men and lose sight of the larger goal: putting humans on Mars.
Mars Direct, as an intellectual exercise at creating a minimalist Mars Mission, was a tremendous step towards getting us to Mars. But while it should inspire better mission design than the Battlestar Galactica ship of old, we should not dogmatically adhere to it.
Zeal + In situ resource utilization + nuclear thermal rockets + closed loop life support + a realistic number of crew for the science mission + opposition-class trajectory = a successful formula for putting humans on Mars.

Don't forget, however, that many of the Moon folk think Mars should, be delayed for 50 or 75 or even 100 years.

Attacking Robert Zubrin's plan becomes a surrogate for saying Mars should be "off the table" until we are ready, with "being ready" sounding very much like my telling my daughter "Yup, we can put that on your Christmas list. . ."

John Creighton · 2004-11-30 09:30:42

Don't forget, however, that many of the Moon folk think Mars should, be delayed for 50 or 75 or even 100 years.
Attacking Robert Zubrin's plan becomes a surrogate for saying Mars should be "off the table" until we are ready, with "being ready" sounding very much like my telling my daughter "Yup, we can put that on your Christmas list. . ."

Mars direct is a fine starting point. I just think when the time comes we should plan a little more carefully. If we don't I will cross my fingers and hope for the best. At least we will be going. I just fear the, "I told you so s

SpaceNut · 2004-11-30 09:41:56

Plan what, the Dollars needed from budgetary years or the proper design of the vehicle or vehicles to do the job with an over estimation of funds needed though contracting to the big guy's in the business.
We could do this today if the funds were given as they are needed to pay for the end product.

GCNRevenger · 2004-11-30 12:38:07

Certainly not, I would be quite happy to hear O'Keefe stand up and say "Shuttle, ISS, and Lunar/CEV projects are all terminated effective 1/1/05 and all monies reallocated to begin work on a manned Martian program on 3/1/05."

What I don't like is MarsDirect. MarsDirect is the problem, that it cannot deliver on its promises without sacrificing crew safety or scientific payload as currently envisioned, and even if it could be pulled off, the four-man crew with limited equipment and the limited options for expansion (clusterd HABs? integrated TMI, no cargo lander, no practical provision for a base) make it a bad investment in the long run.

BWhite · 2004-11-30 15:24:54

Certainly not, I would be quite happy to hear O'Keefe stand up and say "Shuttle, ISS, and Lunar/CEV projects are all terminated effective 1/1/05 and all monies reallocated to begin work on a manned Martian program on 3/1/05."
What I don't like is MarsDirect. MarsDirect is the problem, that it cannot deliver on its promises without sacrificing crew safety or scientific payload as currently envisioned, and even if it could be pulled off, the four-man crew with limited equipment and the limited options for expansion (clusterd HABs? integrated TMI, no cargo lander, no practical provision for a base) make it a bad investment in the long run.

Okay then, use Ares to throw huge payloads to the Moon and then we practice.

SpaceNut · 2004-11-30 15:38:07

What about using a modified Ariane 5 rocket.
Europe's "super-rocket", the Ariane 5-ECA, will be back in action in January 2005, says its operator Arianespace

The world's reference for heavy-lift launchers, Ariane 5 enters service with a 6.5 metric ton payload capability to geostationary orbit, growing to 10 tons in response to the development of increasingly heavy telecommunications payloads.

GCNRevenger · 2004-11-30 15:41:09

Ares is too small for a single-launch direct manned payload to Mars using chemical engines.

The Ariane-V "super heavy" is probobly the most powerful launcher on the block, but its still a medium launcher, only around 35-40MT or so.

Dook · 2004-11-30 17:15:55

GCN:

How is crew safety sacrificed in the Mars Direct plan? Radiation shielding?

I will agree that there is not much of an allowance for scientific equipment but the plan is to gather soil and rock samples and return them to the earth for extensive analysis.

What's wrong with clustered HAB's? And the habitats become a base as each one lands in the same general area.

Remember this is a first landing. A test run, not settlement.

GCNRevenger · 2004-11-30 17:51:52

I don't think that MarsDirect can meet its optimistic mass targets, and so cuts would have to be made. Radiation shielding, spare parts, perhaps micrometeoroid armor, reserve fuel margins, redundant engines, extra artifical gravity cable, various backup componets, and all the "little" stuff (tools, medical gear, repair kits) among other things.

MarsDirect already is going to have to sacrifice its meager science package allowance, the light rovers, perhaps the drill rig, and other non-critical equipment to meet targets I believe, plus the notion that we would bring back rocks for study here is silly since the ERV couldn't cope with their weight... It will have enough trouble just getting off the ground. Besides, we will want to study the rocks on Mars so we know which ones are interesting and should be brought to Earth. We also ought to find out if there is any life in the rocks before we think about boxing them up and bringing them here, which you will need specialized equipment for. (Mass spectrometer, electron microscope, amino acid chirality detector, etc)

Why I am against the "cluster Hab" nonsense:
~We can't land them close together reliably, we aren't that good at landing on Mars yet
~We won't be landing close together anyway, we will be landing all over the surface to explore
~Habs will wear out, and with the long length of time between missions, they will have limited useful life
~When it comes time to build a base, a purpose-built perminant inflatable module should be sent which does not have to cope with getting to Mars already deployed
~Linking together Hab modules may not be as easy as it sounds

smurf975 · 2004-11-30 22:41:34

The ESA will revive the Energia rocket for its space program. Read ftp://ftp.estec.esa.nl/pub/aurora/Human … on.pdf]the executive final report summary. (Its a 40 page pdf) Read the chapter "Launchers" (6.3).

Ad Astra · 2004-12-01 00:46:45

The study recommends reviving Energia, but doesn't necessarily commit ESA to doing so. It would probbly be the cheapest option for ESA, though.

My problem with the study is that it rules out technologies that would dramatically improve our odds for successfully making it to Mars and back. Nuclear power, NTRs, ion engines, and in-situ propellant production are all off the table. Aurora is quickly becoming a re-hash of Battlestar Galactica.

Grypd · 2004-12-01 05:20:40

The study recommends reviving Energia, but doesn't necessarily commit ESA to doing so. It would probbly be the cheapest option for ESA, though.
My problem with the study is that it rules out technologies that would dramatically improve our odds for successfully making it to Mars and back. Nuclear power, NTRs, ion engines, and in-situ propellant production are all off the table. Aurora is quickly becoming a re-hash of Battlestar Galactica.

ESA and europe as far as I know any intention to use NTRs the individual member states would surely block any such research. Of course in the future this may change but its not likely.

Ion engines are the most efficient space engine we have, just they are not man rateable there thrust is too low for it to be the main engine on any manned flights. Look how long it took Smart1 to get to the Moon.

There was nothing too intristically wrong with a battlestar Galactica design other than NASA intended its construction to be the pinacle of its plan, not landing on Mars. If Esa using Energia creates a plan that creates such a sizable space vessel in 5 or 6 launches and makes it reasonably reusable, but keeps the long periods of Astronauts actually working on the surface of Mars, then what is the problem. It looked to me that what ESA wanted to do in this one study was to create a cycler so allowing for increased numbers of crews being sent to Mars. And I have already seen in another docuement that ESA allways plans to use a Hab style approach on Mars.

smurf975 · 2004-12-01 08:29:05

I don't think its a battlestar Galactica design.

They will use a heavy lifter to lift the big parts into LEO and smaller rockets for others. It's really like the building of the ISS. Only now they are thinking of using the Energia instead of the space shuttle and this is more cost effective. And besides Zubrin's plan uses a http://www.astronautix.com/lvs/ares.htm]modified shuttle launcher.

GCNRevenger · 2004-12-01 12:27:13

If the ESA is thinking cyclers powerd by chemical engines, then they very much are going the Battlestar Galactica route which will kill the whole idea. What do you bet that they are thinking about doing a Conjunction type trajectory too?

Multiple Energia launches for fuel on every trip, huge solar arrays to make power at Martian distances to keep the fuel cold, very large aerobrake shield or additional main engine fuel to effect orbital capture, short stays dictated by tight downmass/upmass budgets...

PurduesUSAFguy · 2004-12-01 15:42:01

I think if you throw nuclear thermal rockets into the mix and stick with the as published Mars direct plan then that gives you a much bigger mass margin then you would have using exclusivly chemical rockets.

Also Mars Direct and the DRM were penned before the TransHab project and before Bigelow. (although the significance of the latter has yet to be seen) Inflatable inspace habbitats would significantly expand the liveable volume of the ERV side stepping that problem.

I currently work for the NASA Advanced Life Support Systems project (At Purdue university, as the name implies, lol) and I have to say assides from maybe a minimal 'salad' machine and physio-chemical water and atmoshere recylcing I think closed loop life support is a dead end. With the volumes and power requirments you have to come up with to make it work you'd be beter off using your multi-megawatt nuclear reactors as NTRs or to power VASMIRs or other advanced electric propulsion option. Searching for Carbon and Oxygen closure on Mars doesn't make sense, what makes sense is developing techniques to use what we know is there already. Once we find a good way to extract water from permafrost or if we are really lucky and aquifer the life support problem goes bye-bye real quick.

GCNRevenger · 2004-12-01 16:58:15

Even if MarsDirect did employ a nuclear upper stage and inflatable modules, I think it is still too small, that you could have much stronger exploration and future upgrade capabilities with a NASA DRM style mission.

Plus, if you wern't forced to cram everything into only two flights, that could leave extra mass margins in the likly event a almost-closed LSS system isn't practical.

Dayton3 · 2004-12-01 17:01:34

Yes people.

We all KNOW it would be great to have nuclear thermal propulsion for TMI.

We all know that it would be nice to have a huge mass margin and a large crew complement. I think if we could have a twelve man crew with full sized labs and long range rovers, and even manned hoppers it would be great.

We all know that it would be nice to have massive layers of radiation shielding so that the crew didn't absorb any more than an airliner crew.

We all wish we had a great, well planned manned Mars program that was part of a larger manned program that included a continous stay on the moon, in LEO, missions to near Earth asteroids, a bigger unmanned program.....

We all wish we had solid support from the President and Congress.

We all wish we had fanatical public support.

Friends.

WE ARE NOT GOING TO GET IT!!!

Not one of those. Not now, probably not ever.

If we get a manned mission to Mars, it is almost certainly going to have to be Apollo style. A quick, dirty effort with an incredibly tight timetable and most of the science done on the margins.

Is such a program worth it?

I believe so.

If we lobby hard and get two or three manned missions to Mars over a period of 5 to 8 years or so....EVEN IF Mars gets effectively abandoned for a few decades afterwards (and I think we might be able to avoid that) I think the effort and the return on the time and money will be worth it.

GCNRevenger · 2004-12-01 17:59:09

Dayton, two things...

1: That cutting corners too much is not acceptable, and thus far manned programs that have been rushed or corners cut and margins slashed have time and time again ended in near fatal mishaps and funerals. Apollo had a massive budget and even then resulted in casulties (pad fire) because corners were cut. See also Soyuz-1, Challenger, Columbia, etc. Heavy radiation shielding, enough room to move around, long-range rover, spare/redundant parts, medical gear, and these kinds of things are not optional. If it requires a more expensive booster or a nuclear engine, then it does... Thats the price of doing business, so to speak.

Planning the mission arcitecture from the booster to vehicle to mission and not the other way around is a horrible way to go about mission design, and will yeild a mission worth much less per dollar at best or be dangerous at worst.

2: MarsDirect in its current form is too optimistic about the estimated vehicle mass. It is over-optimistic to the point that it is probobly impossible even with no real scientific equipment at all, which the scientific community would not tollerate and where the crew would become dangerous depressed. MarsDirect simply tries to pack too much stuff onto too small of a rocket in order to save a buck and make "doing Mars" a smaller undertaking. Unfortunatly for Doc Zubrin & Co, a gainful Mars mission is a large undertaking by nature of our rocket engines and fuels, if he wants it to be or not.

You may believe such a mission is worthwhile, but I do not, and I bet that NASA would not be permitted to carry out such a risky and worthless mission.

Euler · 2004-12-01 18:29:08

Also Mars Direct and the DRM were penned before the TransHab project and before Bigelow. (although the significance of the latter has yet to be seen) Inflatable inspace habbitats would significantly expand the liveable volume of the ERV side stepping that problem.

Even with an inflatable the ERV would be very cramped. The manned portion would probably end up being much smaller than TransHab or Bigelow's hab.

Dayton3 · 2004-12-01 19:06:14

Look, as far as I'm concerned, a 10% chance of astronaut death during the mission and a 20% chance of mission failure (ie, they fail to land on Mars or are force to abandon most of their samples and data) are ACCEPTABLE risks.

And I would wager that you would still get HUNDREDS of very qualified astronauts volunteering.

Also, I'll submit that reducing the danger of space missions has also had the effect of reducing public support as well.

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Re: Has Dr. Zubrin Addressed Mars Direct Objections? - A few questions?

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Re: Has Dr. Zubrin Addressed Mars Direct Objections? - A few questions?

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Re: Has Dr. Zubrin Addressed Mars Direct Objections? - A few questions?

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Re: Has Dr. Zubrin Addressed Mars Direct Objections? - A few questions?

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Re: Has Dr. Zubrin Addressed Mars Direct Objections? - A few questions?

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Re: Has Dr. Zubrin Addressed Mars Direct Objections? - A few questions?

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Re: Has Dr. Zubrin Addressed Mars Direct Objections? - A few questions?

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Re: Has Dr. Zubrin Addressed Mars Direct Objections? - A few questions?

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Re: Has Dr. Zubrin Addressed Mars Direct Objections? - A few questions?

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Re: Has Dr. Zubrin Addressed Mars Direct Objections? - A few questions?

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Re: Has Dr. Zubrin Addressed Mars Direct Objections? - A few questions?

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Re: Has Dr. Zubrin Addressed Mars Direct Objections? - A few questions?

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Re: Has Dr. Zubrin Addressed Mars Direct Objections? - A few questions?

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Re: Has Dr. Zubrin Addressed Mars Direct Objections? - A few questions?

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Re: Has Dr. Zubrin Addressed Mars Direct Objections? - A few questions?

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