Where exactly is Mars Direct with NASA? - Are they going to do it or not?

RobertDyck · 2004-09-24 13:18:02

Mars Direct started with an optimization of the vehicle for a Mars mission. Don't bring stuff you don't need; for example make the fuel for return from Mars resources. So I take this one step further: why waste fuel dropping the Earth return capsule on Mars surface, only to lift it again? Why not leave it parked in Mars orbit and use a MAV with unpressurized cabin that is really nothing more than a seat for each astronaut and a fairing. You can lift off from the Moon in a spacesuit, but Mars has an atmosphere. You don't want to be pushed through atmosphere at hypersonic speed in just a suit, even the low pressure of Mars. But you don't need life support or even pressure during the few minute trip up to the orbiting return vehicle.

As for unattended: Mars Direct leaves the ERV unattended during the 6 month trip to Mars, 20 month stay on Mars surface to manufacture fuel, then 6 months waiting for crew to travel from Earth to Mars. A manned mission would spend 14 months on the surface and 6 months getting back to Earth, but the ERV will stay on Mars until the crew arrives. Automated diagnostics can check for problems, but once the crew leaves Earth they're committed. An architecture that uses Mars orbit rendezvous would travel in the ITV, which is the return vehicle. It would only be left unattended in Mars orbit during the 14 month crew surface stay. It sounds to me that the return vehicle is left unattended for a shorter period of time. As for any argument about manual repairs, the crew can do that in Mars orbit before departing just as easily as Mars surface.

This creates a reusable ITV with the first mission. Using a reusable Orbital Space Plane (yes I said that again) to access Earth orbit, as well as a reusable ITV leaves most of the hardware available for a second mission. You only require a new MAV, TMI stage, lander with inflatable habitat, and open rover for the second mission. That's if the second mission goes to the same location; a new location would also require a cargo ship with laboratory, pressurized rover, back-up food supply, and science equipment and supplies.

As for exploration: manned exploration would have made sense in 1989. Now after all the robotic probes that have already been sent, together with the ones in the works (such as Phoenix), we will have enough to choose a base location. I would send one science mission, then send a base construction crew (settlers) to that same location. We could support the settlers with expendable cargo drops and the reusable crew vehicle.

RobertDyck · 2004-09-24 13:20:55

Oh, RobS pointed out that an inflatable habitat would have to be deflated for atmospheric entry on Mars. It's much more difficult to deflate and pack an inflatable, a lot easier to inflate and leave it. Since an inflatable surface habitat must be deflated during Mars atmospheric entry, we're already talking about separate surface and space habitats.

GCNRevenger · 2004-09-24 14:10:05

The trouble with making the fuel needed for the return to Earth on Mars is, you have to get the fuel off Mars first... the amount of fuel needed to get from Mars orbit back to Earth is small enough that you might as well just bring it from Earth. The unpressurized MAV "Chariot" is also small enough to be launched from the surface with fuel brought from Earth such that the bennefits of ISRU for rocket fuel are limited given the complexity & cost of the system... It can be equally said that the ISRU plant then qualifies for "don't bring stuff you don't need."

The Orbital Space Plane concept is dead. D-e-a-d dead. NASA, with its sights set on a return to the Moon for the least practical cost have no choice but to use a capsule or sled arcitecture to make direct Luna-Earth reentry possible, no winged vehicle is viable given the velocity. So, since NASA will have a robust, sturdy, and relativly inexpensive capsule in hand by the time Mars rolls around, and the small numbers of people going to Mars, then there will be no motivation to build OSP given its development cost. It will serve well enough as an ISS transport too if called upon to serve that role. This bird has no wings... the CEV capsule may also work for Mars-Earth return too.

Having a reuseable orbital transfer vehicle sounds well and good on paper, though I wonder how long it will really last, as if it doesn't last for multiple missions you might as well send an expendable HAB like MarsDirect or SemiDirect. I am also quite sure that it will take more than a fresh TMI stage to make the thing ready for a mission, and will probobly take a CEV crew several weeks plus 1-2 cargo CEV flight to clean, repair, and restock the vehicle. If it can be fixed in orbit at all.

There is also a concern, that if the minimalist lander fails to land near the HAB or the MAV, the crew is history... with no long-range rover available to the crew on the lander, small navigational glitches that were once no big deal are now quite fatal.

And who says an inflatable module must be deflated for reentry? How big is the aerobrake/heat shield? Why is it not practical to make it wider and a little sharper? Inflatable heat shields have also been flight tested, why can't the inflatable have this material on its entry-facing side?

No settlement beyond a small (<25 most likly) fixed contingent of science & engineer staff is going to happen until we have a reuseable launch vehicle from Earth, and thats about all there is to it, which limits this kind of activity into the further future when NASA has development dollars for this type of infrastructure and the colony payloads themselves.

Palomar · 2004-09-24 14:41:43

Robert D: You can lift off from the Moon in a spacesuit

*That's right.

It's something to actually stop and think about it.

Up, up -- and away!!!

Would have to have a cape on the spacesuit, though. :hm:

Forgive me...I'm in a different sort of mood today (too much chocolate). Back on topic...

--Cindy

Mark S · 2004-09-24 15:46:26

There ought to be a water/polymer/aluminum "inner core" the astronauts would sleep in, doubling as storm cellar and reducing flight radiation doseage... Heavier? More expensive? Sure, but its this kind of thing thats worth it... You won't have Mars dirt to shield you to and from where cosmic rays are strongest.

Studies have repeatedly shown that polymers like polyethylene would make the best shielding for the spacecraft to protect it from the harsh radiation of deep space. I think this is another example showing why Mars Direct needs to be fleshed out more.

The more we learn about Mars, the more we must add to the plan, and the more unrealistic it becomes. Will we have to switch to a 200 MT to LEO rocket to launch it all, like NASA proposed in the 1993 DRM? Should we take the high road of really big rockets, the low road of many EELVs, or the moderate road of ~80 MT boosters? I still favor the SDV, and I still support something like the Stanley Borowski "bimodal NTR" plan for getting to Mars.

GCNRevenger · 2004-09-24 16:00:44

There are really three kinds of space radiation, high-energy EM, Proton, and heavy nucleii radiation. I wonder if doped polyethylene works best for all three or a combination of it and aluminum or bulk water.

Well, what I know for sure is that without a nuclear TMI stage, the MarsDirect arcitecture as it is now is too small, and cannot be enlarged because it isn't practical to make an SDV lift more than about 120MT, the modifications nessesarry would be so signifigant that you might as well start over and build a new rocket.

I don't see any particular reason that a 200MT class rocket could not be built with exsisting or slightly modified (RS-68 Regenerative, 5-Segment SRB) engines, but that would be a signifigant investment. My money is split even between a new clean-sheet >150MT class booster or missions carried out with pairs of 80MT Shuttle-C rockets, barring use of NTR engines.

Edit: *Thinks...*

A massive rocket, the MOR "Mars Orbital Rocket" (blah blah really the Mother of All Rockets)... Four of the new 5-segment SRBs, five RS-68R engines on the bottom of a massive 10-11m wide core for the first stage, and a single RS-68R upper stage perhaps 12m in diameter...

More Edits:

If aerobrake shield diameter is a problem, I wonder... send up an inflatable one, inflate it in Earth orbit before TMI burn and inject it full of hardening foam, but this would probobly need there be an abort mode where the vehicle enters a circular Earth orbit for CEV pickup if it is a direct flight in the event of inflation failure. Piece of cake for a multi-componet LEO rendevous mission design... Launch the TMI stage and Mars ship on a pair of Shuttle-C's and the crew on CEV.

John Creighton · 2004-09-24 17:28:18

GCNRevenger you present some interesting alterations to the Mars direct mission. Have you ever worked out the numbers. Where would your plan beat mars direct or NASA reference mission. Would it be cheaper, would it leverage more mass to mars, would it allow more people would it be safer. I am just curious how everything works out. I think Zubrins plan was a good start but if you can beat it lest see it. That is if you have time. I know PHD’s take along time to do. In my field a PHD is usually about three years

GCNRevenger · 2004-09-24 17:53:31

They aren't really my alterations overall, the biggest thing is making the mission in three pieces to give enough payload mass for a crew of six using the biggest SDV (or smaller 80MT w/ NTR TMI stage) which is embodied in NASA's Design Reference Mission III, aka "Mars SemiDirect" which calls for a separate ERV to be placed into Mars orbit instead of launched from the surface... My "edits" are to possibly make the HAB larger still using an inflatable structure if its not practical to build from Aluminum (perhaps with inflatable aerobrake shield?), require that the main long-range rover be a part of the HAB payload, and possibly launch it and the other two componets in two flights each with a dedicated TMI stage in order to reduce launcher size or increase payload.

RobertDyck · 2004-09-24 18:11:24

The aerobrake shield I have in mind is fabric made from the same pure silica as the outer layer of thermal blankets on the Shuttle. That is woven fibreglass, but not just any fibre, highly pure silica. Such a fabric is reusable, and can be supported with a frame that's unfolded after launch. There's no need for a hardening foam. This isn't sufficient for atmospheric entry, but it is for aerocapture or aerobraking.

Radiation: heavy material like lead are bad for heavy nuclei radiation. The nuclei tend to break up creating more particles than you started with. Liquid hydrogen is best because it doesn't break up the nuclei. Material with a lot of hydrogen is second best; such as water or hydrogen doped polyethylene. Lead works for proton radiation, but liquid hydrogen, water and doped polyethylene work as well. UV-A, UV-B, and UV-C are pretty easy to stop; even sun screen with stop them.

Absorption of X radiation by any substance depends upon its density and atomic weight. The lower the atomic weight of the material, the more transparent it is to X rays of given wavelengths.

I don't know about gamma rays; they do penetrate deeply. How much gamma radiation is there in space?

GCNRevenger · 2004-09-24 18:28:33

Yes yes I know that light nucleii are better for particle shielding, but there are Gamma rays and things even more powerful than Gamma that are nicknamed "cosmic rays," which I think can be blocked by different dopant (lead metal powder, boron) Polyethylene but I don't know for certain.

Since a cycler wouldn't be reentering ever, then you don't need the aerobrake shield to be un-deployable. So, it makes more sense to pump it full of light weight foam, as it would not need collapseable supports to stay rigid and would be very resistant to micrometeoroid damage. The foam could be a Polyimide maybe to resist melt/burn damage caused by punctures in the shield that would otherwise melt structure componets ala Columbia or permit a bigger tear if there is no backing that maintains the aerodynamic shape of surrounding cloth.

For a shield that can survive deorbit down to Mars though, I don't know if silica cloth would suffice on its own, but i'm sure there are flexible materials that can if there are ones that work for Earth entry. In such a case, the foam injection to maintain rigidity over the large size of the inflatable HAB would also be used as it is so rugged, light weight, and compact.

RobertDyck · 2004-09-24 18:50:05

Actually cosmic rays are radiation from outside our solar system, mostly high energy heavy nuclei.

GCNRevenger · 2004-09-24 18:58:28

Some of it is high-energy EM too, though I am not well versed on how much.

Austin Stanley · 2004-09-24 22:29:02

Alot of material here, this might require more than one post...

Thats what you get for trying to debate two groups of people at once. FWIW, I agree with you on the whole Mars Direct v. DRM thing. I would recommend picking up a copy of Mars Direct though, it's definetly worth the money.

In the long run, cargo and crew probobly ought to be separated as you say... but this is not the long run. You really have to weigh the extra expense of developing two different vehicles. Plus, a cargo mission and a human mission, without the aid of heavy tugs, do share alot of hardware in common. They would anyway probobly use the same launch vehicle at least to reach orbit, they will probobly use similar landers as the airbag landing aproach is not good enough for cargo, they will use the same OMS engines & aerobrake shield most likly... Putting some of the cargo and humans together saves having to send an additional cargo flight, and for pure cargo missions a HAB-less HAB lander/shield on the same launcher makes sense.

You are right, a crewed and a cargo mission will share much of the same equipment, which is why it makes even more sense to seperate them early on. The primary cost is the R&D of a new item, not just building and instance of it. And since they share so much of the equipment in common (same HLV, similar TMI stage, similar decent vehicle), paying the small additional cost to build, for example, a TMI stage that can do a minimum energy transfer orbit for the cargo or a faster one for personel makes more sense, since building another TMI stage is just a fraction of the cost of designing one that can do both (or two similar ones).

Now, while it might cost slightly more to send two missions, you get many other benifits for this as well. Primarily safety, if you seperate non-vital cargo from the primary mission, thats more mass you could spend on safety equipment. It also helps to bring the overall mass down, which helps to mitigate the cost. Also, by splitting your mission like this you reduce the risk that a single accident will ruin the entire mission. And finaly of course, you end up with more mass on Mars, which is always a good thing.

I also disagree with you that a 500km exploration radius from the landing site is good enough; we want to explore Mars, ALL of Mars, and that means going almost anywhere on the entire surface. Not 500km, but 5,000km would be a good figure if you are going to limit yourself to one site. A rover with that kind of range short of nuclear powerd would be impractical.

Well I would argue that is an aweful lot of ground to cover, ~785,000km^2. A team would be hard pressed to cover even a fraction of that in the two years they are to cover it. They would have to cover over 1,000km^2 a day to do it all (assuming a 500 day mission).

But even so, since the infastructure is developed gradualy, there is no reason we have to expect to explore it all in the first couple missions. Assuming a reusable MAV takes about 6 years to develop teams could be out exploring all of Mars after only 4 missions, the secound team would just be arriving home by this time, and everyone else would have the whole plannet open to them. And the savings they would have in mass and money are huge, as are the increases in safety and science. All for only a two mission delay in getting the "real science" started.

The key to an infastructure development plan is the sooner you get the material on Mars, the sooner you can start saving money. The sooner you put the heavy science equipment up there, the sooner it can be used, and the more you can use it. And the less material that has to be duplicated in future missions, the more NEW material you can send, compounding the effect further. That is why I support infastructure development starting from day one on Mars.

There is finally a question, how safe is safe enough? How much safer does "stacking" old HAB modules, ISRU plants, and reactors make the mission? Is it not safe enough without this option? Is it worth the huge loss of science and inspiration of exploring Mars to be just that little bit "safer?" I think that it is not... Somewhere, sometime, you simply do have to trust that a system will work, and I think that one set of equipment with an anytime-return ERV is safe enough. Nobody said this would be a safe endeavour.

When exploring another planet, you can NEVER be safe enough., the question of course is what does that additional safety cost. But when doubling the amount of safety a crew has to rely upon cost you so little, why not do it? And why waste the mass on future missions by sending the same stuff you already sent to Mars before, when it is sitting right there on the planet waiting for you? You could be sending new stuff, expanding your capabilties for science and other endevors. Scattering your mission out about the planet may enable you to collect data from other parts of the planet that may not inital be avaliable, but I do not think it is worth the enormous waste in mass, nor is it as safe as single mission approaches. And by bringing new equipment to the site (instead of repeats of old), you add the ability to collect new kinds of data.

-----

I actualy think we are pretty close to agreement on these issues. We both understand that value of infastructure on Mars, the diffrence is that I don't see any reason to wait for some arbitrary date/technolgoy to establish a permanat base and start building the infastructure up. You get maximum benifiit from doing it on day one. As the technology advances as new methods of delivery become avaliable, by all means use them. But waiting untill those are avaliable means wasting all that money you could have saved by sending it earlier. As I showed before infastructure (like a big permanat nuke) could pay for itself very quickly, and these savings are not dependant upon advance deliver options, so why wait for them?

Just to give you an idea, this is how I would develope infastructure on Mars.

Cargo Mission 1:
A pair of pressurised long range rovers, the mass that is saved from sending them with the crew is spent of safety and reducing the mass.

Cargo Mission 2:
Heavy drilling and Earth moving equipment, with two rovers already on mars, there is no point in sending another one.

Cargo Mission 3:
ISPP, and air liquification facilities, these should help to reduce the amount of LSS equipment that has to be sent from Earth.

Cargo Mission 4:
Large Nuclear reactor, which should eliminate the need to send nukes on later missions.

Cargo Mission 5:
Reusable MAV, which gives both global range, and eliminates the need to send single use MAV vehicles.

And so on... with the exceptions of mission 4 and 5 all of this equipment is fairly low mass, probably under 10 tons. I like the idea of 20-40 ton cargo missions which gives pleant of space to send spares, supplies, back-ups of key infstructure equipment and so on. Under this plan the Mars base has much greater capabilities, and is safer overall. And little is sacrificed.

GCNRevenger · 2004-09-25 02:43:55

Let me clarify and better lay out my philosophy for initial missions:

The purpose of the early missions should be exploration. Period. This means that you must be able to reach many different locations to be making scientific and social returns in the shorter term in order to keep the customers - taxpayers and Earthly scientists - happy and further funding will take care of itself; a Martian McMurdro is the last thing we need initially. A 500km rover is insufficent to "see the sights" so to speak, the area coverd isn't really important, its just that you can't go see interesting or high value things if you are tied to the 500km radius near base. People will not be tollerat of waiting; waiting until years later, perhaps a decade later to be able to venture much beyond base camp is not acceptable.

Second, the infrastructure you describe... heavy nuclear power plant, large perminant HAB, heavy long life ISRU fuel plant, and the two biggies - a reuseable MAV vehicle and a useful Martian water supply - I believe will itself require much much more money and time to develop and construct than you think. These items which are in addition to the "Exploration class" gear are not easy to build (super MAV, reloadable reactor, ice mine), they are not simply extensions of throw-away hardware needed for initial flights, especially securing Martian water and the heavy reactor to fuel the MAV's big appetite for Methane will not be easy... waiting or paying for these either to accomplish real exploration is not acceptable.

Third, if we are going to use a NASA DRM-III based mission, splitting up the cargo entirely from the HAB module for early missions is also a bad idea; if mass is a problem, then the problem is with the launcher and not the vehicle.
~~As the MAV vehicle will be riding seperate from the HAB, the HAB must therefore carry the long-range rover in order to rendevous with the MAV in the event of a landing miss.
~~The HAB should also carry a power supply & consumeables capable of sustaining itself for the duration of the mission in the event of a miss. The HAB could carry the reactor if MAV uses fuel from Earth.
~~The HAB should also carry the Mars Laboratory and some of the science gear, as it does not make sense to separate the lab from the HAB, as they are both pressurized.
Some of the cargo must ride with the HAB and the science payload will not be that huge: this isn't like LEO launches, splitting the cargo up entirely without a very very reliable landing system is not acceptable.

"When exploring another planet, you can NEVER be safe enough" Forgive me when I see this I tend to balk, but I want to remind that the only way to be "safe enough" with this mindset is to not go. As for the "doubling of safety" it really isn't a doubling of safety... The prior missions' reactor will be at the end of its life and will not be able to serve as a replacement for yours, the HAB module may not be reliable for nearly double its design life, no MAV backup, but overall the biggest risks are still in landing and launch: having duplicate everything on the surface will only provide a small return in reduced probability of mission fatality, which is ultimatly the true measure of safety.

Overall:
-I think that early returns in exploration are more important than building infrastructure even at higher cost for both scientific and "inspirational" reasons as patience with NASA particularly following the Shuttle/ISS "science! science! no really!" debacle will not be plentiful if we get to Mars and just sit... just like we have in Earth Orbit for so long.

-The cost in time and money for developing these infrastructure items will be very high and will not replace the (much lower) development costs for initial exploration missions, which even if they save money in the long run per mission will strangle today's pay-as-you-go NASA budget.

-The ship(s) to go should be large enough that the crew and some of their cargo can ride on the same flight as a safety measure and to consolodate some componets plus avoid the need for a seperate dedicated payload to achieve useful results per-mission. If this requires a bigger HLLV rocket, an NTR TMI stage, or more than one launch per payload then that is the price of doing business with this arcitecture.

To finally finally finally after fifty years since we left the Moon we set foot on Mars... and we can't go over the next-next hill for another ten or twenty? No thanks!

RobertDyck · 2004-09-25 05:35:01

An exploration radius of 500km is as big as Texas or Alaska, from central point to state borders. That radius is pretty big. Yes, a DC-X style reusable MAV is nice, and I do advocate such a vehicle for later flights, but not initially.

Perhaps this is getting philosophical. I don't see a manned mission to Mars as just exploration; I see it as settlement. And I don't mean just McMurdo, I mean Plymouth Colony, location of a boulder called Plymouth Rock. Scientists will always view science as paramount, but that is only one aspect. Settlement (some political science types don't like the word colonization) would mean a research institute for scientists, but also industry to make a profit, and frontier settlement for homesteaders. Just one aspect alone will never happen, it must be all three together.

Again, science missions to scout the best location for a base were appropriate in 1989. Now we have had Mars Pathfinder with its Sojourner rover, Mars Global Surveyor, Mars Odyssey, Mars Express, and launched in 2005 Mars Reconnaissance Orbiter, in 2007 Phoenix, in 2009 Mars Science Laboratory, and either launched late in 2011 or early 2014 a Sample Return Mission. All this adds up to advance scouting performed by robotic probes. Next we need a permanent base. The human vs. robotic debate is now moot, robotic scouting is complete. Next we need scientists to spend extended durations on Mars to study it in detail. A 14 month mission is just a start, we need a base. Yes, that will be a McMurdo for science missions, but it'll also be Ellis Island.

One reason industry is so necessary is to earn profit. A relatively modest investment will start earning money. That money will help pay for further development. In terms of the Mars Homestead project, minimum tools and equipment will be sent which can utilize local resources to build more tools and more equipment. Start small and grow, don't try to pay for everything with up-front capital investment. Minimize the capital investment while maximizing return.

This sort of financial viewpoint is not what most research scientists want to hear, but it is how congress looks at it. Congress gets more money via tax revenue from the space industry than it spends on NASA. That's due to commercial satellites like DirectTV, commercial weather satellites, resource prospecting satellites, and more traditional communication satellites like TV (ABC, NBC, CBS, Fox, PBS, CNN) as well as telephones. NASA built the technology to make this happen, but commercial space operates on its own now. Military is another animal entirely. But congress does look at tax revenue from the space industry vs. investment in NASA, and NASA will always get less; there has to be financial return. We could start a debate regarding how to make a profit, but that's for another thread. What I am saying is that profitable industry must be an early component of any manned presence on Mars.

John Creighton · 2004-09-25 10:03:52

GCNRevngers main points seem to be about mobility. I assume he wants to visit all the major landmarks of mars. Much of the initial payload will be reusable. This includes science equipment, tools, vehicles, drills and possible earth moving equipment. There is no reason to bring the same stuff each mars mission when we already have it here. If the nuclear power plant is at the end of its life and enough fuel was carried over for the mars assent vehicle maybe there would still be a lot of left over full methane tanks that could be used to power the base and vehicles. Moreover any water produced will mean there will be less water necessary to bring for future missions. If we really want to explore maybe a lot of the equipment from previous missions can be hauled by trailers. Later tellerobotic earh moving equipment could be used to build roads and maybe even bridges.

Martian Republic · 2004-09-25 12:25:38

GCNRevngers main points seem to be about mobility. I assume he wants to visit all the major landmarks of mars. Much of the initial payload will be reusable. This includes science equipment, tools, vehicles, drills and possible earth moving equipment. There is no reason to bring the same stuff each mars mission when we already have it here. If the nuclear power plant is at the end of its life and enough fuel was carried over for the mars assent vehicle maybe there would still be a lot of left over full methane tanks that could be used to power the base and vehicles. Moreover any water produced will mean there will be less water necessary to bring for future missions. If we really want to explore maybe a lot of the equipment from previous missions can be hauled by trailers. Later tellerobotic earh moving equipment could be used to build roads and maybe even bridges.

You wouldn't need to build any bridges on Mars, because you would not have to cross any rivers on Mars. If you were going to do that, one road grader would do it for you. It would be much more than cow path like the old wagon trains of yesteryear use to travel on. But, Hey, this is a frontier settlement. So what did you expect, any way?

What ever we do on Mars, it going to be expensive and there no way to get around it. Even if we go with the Mars Direct plan and forget about all this other stuff that either side is pushing, it still going to be expensive. To do one Mars Direct is was projected at about 8 billion dollars with each additional Mars Direct being about 2 billion apiece. So we should do five or six Mars Directs Mission to Mars, because each newer mission will use the base of the older mission. So that would be about 18 to 20 billion dollars. That assuming that there no cost over runs to build the equipment or creeping on the amount of item you have to send to Mars so you don’t have to send two buster instead of one or make the buster twice as big, which will also add to the cost. Now that in 1989 dollar value of what currency was worth. That was fifteen years ago and we have not added the cost of inflation in on the new price for the Mars Direct either. We can figure that every twelve years or so, the value of the U.S. Dollars decreased by about 50%, so that means our project will take more dollars to complete and double the price of our Mars Direct Missions. This also kills any argument of making a Mars Mission profitable too on the front end too. In the present economic system and political arrangement, it is very doubtful that we will even get to Mars, let alone have something like several failed ISS projects along the way. Also in the current banking system, we couldn’t round up the money to do it even if there was a national desire by the American people to do it either. So it doesn’t look promising at all for what we want to do.

The only thing that you can sell to the American people is the vision great things we are going to be doing and the technology spin-off that will improve life here on earth if you do Mars Projects. Without giving the Treasury department the right to generate credit the way FDR did, we would have no way to fund that project. Any serious effort to go to Mars or setup a settlement is going to demand that kind of financing and just raising taxes on the American People, is just not going get. Beside you will alienate the people your trying to convince that this is what they want to do.

For the VISION part, we might show them a Martian City.

For the TECHNOLOGY SPIN-OFF part, we remind them that the moon returned $14 dollars for every $1 dollar invested in the Moon Mission and Martian Mission are bigger and more massive and we will have to develop more technology than the Moon Mission and so we expect a bigger return on our investment. Also it a job creation program too. There were two million more jobs during the Moon Mission than before or after those Moon Mission.

Without an FDR approach to the financing it, there will be no paying for it either. Of course there will be no paying for either one of or several plans that you people are putting out there either.

Reason:

“NO MONEY TO PAY FOR YOUR DESIRED PROJECTS”!

Your going to have to tell the American people what your vision is and what kind of benefits that there going to get out of the Mars Mission and how you intend to pay for it. Then you have to come up with a battle to accomplish so the American people can follow your progress and that your actually doing it and that it actually getting done. Now we are assuming that we have access to the U.S. News Media and if we don’t, then we need to set one up so that the Americans can follow the progress or otherwise they will lose interest and there goes our financing too.

Larry,

GCNRevenger · 2004-09-25 13:25:35

"GCNRevngers main points seem to be about mobility. I assume he wants to visit all the major landmarks of mars. Much of the initial payload will be reusable."

Yes and no. I think that being stuck within a small radius of a fixed initial base will not be able to venture to enough sites of interest to effectively explore Mars... People know that Mars has huge moutains, massive valleys, mamoth glaciers, extinct seas, impact craters and so on and so on, which hold the scientific and inspirational keys to Mars. People will ask, with all the majestic sights and secrets, why are we stuck driving around the same red hills? Did we come to explore or to build an ISS-on-Mars? Why are we building a base? We don't need a base to explore Mars after all.

Without an extremely expensive reuseable MAV vehicle, a large power plant, a large fuel factory, and a supply of water to operate it then the only way to go to these places is to send separate missions to each one. As the expense of these items would be quite large, they cannot be afforded early in the Mars exploration phase anyway.

No base, no infrastructure, no reuse of hardware... Reuseability costs too much early on, expendability is more affordable. People will be impatient, unimpressed, even suspicious if there is much in the way of delay. The loss of science by not being able to visit multiple sites worldwide will make the Scientific folks balk at the whole mission... The base, the perminance, all that will have to come later: NASA has to achieve real results without breaking the bank or taking too long, which precludes spending ten and eleven digit sums for base hardware during the exploration phase. Later our technology will also be more mature and will make going beyond a Martian McMurdro possible and it is not quite there yet today, so being in a big hurry to build a base NOW doesn't make the greatest sense.

Hey MartianRepublic, I think we have all seen or heard about your... unique... perspective on the economic problems concerning large government projects, might you consider simply linking to older topics instead of writing large posts that say the same thing over and over?

John Creighton · 2004-09-25 19:10:24

GCNRevenerg is it your opinion that enough of mars can’t be explored by wagon trail or is it your opinion that the wagon will weigh too much. Clearly some equipment is not expensive to make reusable like, a hammer, a drill, solar panels, methane tank, watter tank, etc. Clearly if enough of the equipment is reusable it will be cheaper to land near the old site and salvage the reusable equipment. Thus there are too issues. The first is how much cheaper does reusing old equipment make the next mission. The second is it worth the additional cost to abandon all of the old equipment.

Martian Republic · 2004-09-25 19:26:00

Hey MartianRepublic, I think we have all seen or heard about your... unique... perspective on the economic problems concerning large government projects, might you consider simply linking to older topics instead of writing large posts that say the same thing over and over?

I may consider that.

How the best way to set up the link?

Larry,

SpaceNut · 2004-09-25 19:35:39

GCNRevenerg is it your opinion that enough of mars can’t be explored by wagon trail or is it your opinion that the wagon will weigh too much. Clearly some equipment is not expensive to make reusable like, a hammer, a drill, solar panels, methane tank, watter tank, etc. Clearly if enough of the equipment is reusable it will be cheaper to land near the old site and salvage the reusable equipment. Thus there are too issues. The first is how much cheaper does reusing old equipment make the next mission. The second is it worth the additional cost to abandon all of the old equipment.

The problem I forsee for reusing what ever is left behind is only a problem if the new site to be explored means sending a new base habitat since the old one what be hard to move without the right equipment to make it mobile.

RobertDyck · 2004-09-25 22:42:53

Cargo can either take a Hohmann trajectory for 8.5 months instead of 6 months, or use electric propulsion for even less fuel load and greater mission time. An ion engine with the trajectory that Deep Space One was originally going to use would take 2 years to get to Mars, but an Isp of 3000 seconds. The Glenn Research Center has developed a high power ion engine with 10,000 second Isp. You get away with less redundancy for an unmanned vehicle. I was told that any manned mission requires a backup for any mission critical system, and two backups for any life critical system. An unmanned system can use a single reliable system.

One argument I had was to carry a long-range open rover capable of carrying one or two astronauts (Pascal Lee prefers single-person ATVs to a lunar buggy), and extra life support packs. In event that lander is far from the MAV, a single astronaut go will get the pressurized rover and bring it back. This permits a single small vehicle with the crew, and heavy cargo sent unmanned. The laboratory would normally be connected to the habitat, and air ducts from the hab provide life support. However, as a backup life support in the pressurized rover can supply the laboratory. With crew living in the lab they wouldn't be able to use it for lab work, but a backup is only supposed to keep crew alive. The cargo lander would land via beacon and lidar right beside the MAV, so mission control would ensure it landed correctly before astronauts left Earth. That means the backup hab is already waiting beside the MAV.

Again, keeping with the philosophy that backup is just to keep crew alive, the lander wouldn't have science instruments.

My approach is to not include redundant systems, eliminate duplication. Backups are formed by giving an alternate application for a primary piece of equipment. Eg: the lab is the backup hab, the pressurized rover is life support for the backup hab.

By the way, I was an advocate of Energia before the roof of building #112 collapsed. Shuttle-C looks better than Magnum. But we can go to Mars with launch vehicles we have now. A nuclear reactor for Mars surface in imperative. Nuclear TMI stage is going to be necessary, but let’s not hold the first manned mission hostage to that technology. Reusable MAV would be nice, but again don’t hold the mission hostage to it. Robert Zubrin’s hopper would extend mission range greatly without a suborbital MAV.

Finally, if the MAV is reusable then you can’t use it as an expendable TEI stage. That demands not only a reusable propulsion stage for the ITV, but a tanker to refill the propellant tanks in Mars orbit. A lot of infrastructure is necessary to make a reusable MAV practical, which is why I say it’s impossible for the first mission. A reusable ITV with replaceable propulsion stage is practical for the first mission.

Martian Republic · 2004-09-25 23:07:57

GCNRevenerg is it your opinion that enough of mars can’t be explored by wagon trail or is it your opinion that the wagon will weigh too much. Clearly some equipment is not expensive to make reusable like, a hammer, a drill, solar panels, methane tank, watter tank, etc. Clearly if enough of the equipment is reusable it will be cheaper to land near the old site and salvage the reusable equipment. Thus there are too issues. The first is how much cheaper does reusing old equipment make the next mission. The second is it worth the additional cost to abandon all of the old equipment.
The problem I forsee for reusing what ever is left behind is only a problem if the new site to be explored means sending a new base habitat since the old one what be hard to move without the right equipment to make it mobile.

So now we have a choice, 8 billion dollars per site for a mutable of four or five site sites. Or 8 billion dollars for site and 2 billion more to restock the old site. This is according to the Mars Direct plan of the Martian Society. If that anywhere close to being correct, then going to five or six different site will cost twice as much and going to one site would cost. The eight billion that your spending to prepare that one site so humans can live there for two years will have to be spent five of six time depending on where you want to land next and how many times you want to land in a different spot.

Going to a different spot Going to the same spot

8 b X 5 = 40 billion dollars | 8 b X 1= 8 billion dollars
| 2 b X 4= 8 billion dollars
---------------------------------|------------------------------------------------
40 billion dollars | 16 billion dollars

Big difference, even if you had to replace some of the equipment, it would still save a whole lot money.

Larry,

GCNRevenger · 2004-09-26 08:54:59

"Big difference, even if you had to replace some of the equipment, it would still save a whole lot money."

Wrong way to think about it... yes, reuseing some of the old hardware would indeed make missions cost less money, BUT, let me place special emphasis on this, but it would accomplish much less exploration! So yes it costs fewer dollars, but is it really cheaper? Also, I don't think that that a $6Bn difference is realistic... How can MarsDirect save so much money if it needs a new HAB and a new ERV and a new reactor on every flight?

Plus, if people see big inspiring progress happening on Mars, video tours of Astronauts weaving through towering glaciers, standing at the edge of the biggest canyon in the known universe, that sort of thing that you can't do from one landing site, then it will be easier to convince them to continue Mars funding... So again, is it really cheaper if you don't pay big at first, you won't have money later... selling the future to same a dime on today... saaay thats a familiar theme, sounds like Shuttle!

GCNRevenger · 2004-09-26 09:18:29

Ion drives sound really nice, but the size of ion tug needed to push a MarsDirect/SemiDirect sized payload in a reasonable time frame is going to be big. Real big, so its going to cost real money. You need gobs of electricity to power such an engine, more then JIMO's little reactor... this makes such a tug a great long-term "McMurdro Phase" investment, as it would save having to launch a TMI stage (if we don't go direct), but I don't think its worth the money early on.

"In event that lander is far from the MAV, a single astronaut go will get the pressurized rover and bring it back."

Ummmmm no. The MAV vehicle is the single biggest and heaviest piece of the Mars surface payload other then the HAB (maybe), carrying it on a rover tailored for minimum mass isn't going to happen. The MAV or ERV is going to stay put where it lands, so you must bring the crew to it or carry the MAV on the manned lander.

"The cargo lander would land via beacon and lidar right beside the MAV, so mission control would ensure it landed correctly before astronauts left Earth. That means the backup hab is already waiting beside the MAV."

I don't know if I want to place so much faith in accurate landing, the especially with entry at transfer velocities with an aerobrake... One way or the other, there should only be two HABs involved with the mission, either one to carry the crew from Earth to Mars surface and back from surface or orbit, or else one to Mars orbit and one on Mars surface. Three HABs is excessive, and any which way the landing vehicle must carry a long-range heavy rover or a MAV/ERV vehicle. Since the HAB is pressurized and the Lab is pressurized, whichever HAB stays on Mars should have the lab integrated into it.

"But we can go to Mars with launch vehicles we have now. "

I don't agree, I don't think that any Mars mission is economical with payloads that small. Even MarsDirect with its ultra-bare-boned aproach calls for minimum payload size almost double of the Delta-IV HLV. Separating the payload from its Mars lander might get you close, but that and TMI stages is going to add up to alot of orbital assembly, which is a bad idea. Two launches for a 40MT+ payload, tops, including humans.

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