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#101 2004-06-18 16:06:44

BWhite
Member
From: Chicago, Illinois
Registered: 2004-06-16
Posts: 2,635

Re: The Case Against Mars - Why Mars is not a good target!

What space does offer is unlimited resources to a world that is beginning to starve for them. We need those resources to allow our civilisation to go on. We need those resources so we can tackle our planets problems.

Unfortunatly, that isn't entirely accurate... no, we don't really need the wealth of space for Earth. The population of the Earth will probably plateu at around 10Bn people, with genetic engineering feeding them all will be pretty easy, and there are 100's of years of coal, thousands of years of uranium/thorium, and tens of thousands of years of deuterium for fusion in our oceans... As for other reasources, water, metals, polymer feedstocks, etc I think we could get by just fine with extensive recycling.

The notion that we have to go to space because we're going to "run out" of things will easily get torpedoed in congress or somthing... The only thing in space we NEED is the one you can't put a pricetag on (yet)... it is the next land over horizon that has drawn us since the beginning.

Exactly.


Give someone a sufficient [b][i]why[/i][/b] and they can endure just about any [b][i]how[/i][/b]

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#102 2004-06-18 17:23:11

Grypd
Member
From: Scotland, Europe
Registered: 2004-06-07
Posts: 1,879

Re: The Case Against Mars - Why Mars is not a good target!

This beggars the question, why will the population of the earth plateau at 10 billion. It might but a lot of starvation and social disasters will come of it first.
We are in a planet which is in flux, Many scientists say and evidence does indicate that we are suffering global warming. What does it mean. It means that the life supporting capacity of this planet will reduce.

Do we let it or do we do something about it. As much as i would like it there is no chance for the richer western states can afford physically or diplomatically to bankrupt themselves to sort the ills of the poorer part of the world. If as we well suspect the weather gets worse and water levels rise this could mean billions starving.

Improvements in food like gm crops are not a definite. Some states like the united states have little or no problem with these. But in Europe GM crops are hated worse than Nuclear energy. Also coal is the dirtiest fuel about it is one of the prime contributors to Global warming and acid rain. It is actively being stopped.

Water now that is the problem. It is water that will be or a prime contributor to most wars that will happen in the future. It is a finite resource is pure drinking water and it is easily damaged. Ground water in most african and middle eastern states is either at a low amount or polluted.

Recently you may have noticed that fuel prices have gone up. Well some of it was due to global security issues but the main reason was China. China is becoming a major power, its people want the luxuries they see westerners have. Well they are getting them car ownership has increased in shanghai by a 1000% in one year. Soon 300 million chinese farmers in the hinterland will have satelite television.

Do we have enough resources to provide 10 billion people to have two cars each family, incredibly cheap fast food on each corner the answer is NO


Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.

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#103 2004-06-18 17:28:00

MarsDog
Member
From: vancouver canada
Registered: 2004-03-24
Posts: 852

Re: The Case Against Mars - Why Mars is not a good target!

Space is happening; the military cannot do without it. Communications revenue and space tourism will continue to increase. The educational and inspirational value is priceless.
-
The expense will decrease with technological progress. Self replicating systems are in the near future.
-
People go on cruise ships, why not a romantic cruise around the Moon ?

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#104 2004-06-18 17:29:35

Grypd
Member
From: Scotland, Europe
Registered: 2004-06-07
Posts: 1,879

Re: The Case Against Mars - Why Mars is not a good target!

Off the rant for a bit

What the resources of space do allow is for us to grow. Civilisations that remain static things die. We need to keep expanding, We need to have new ideas, New frontiers. Lets hope we get the chance.

We are at a crossroads we can stay on Earth and remain as we are
Or we can grow.
In the end it is up to us the enthusiast to decide.


Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.

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#105 2004-06-18 17:56:24

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: The Case Against Mars - Why Mars is not a good target!

Ahhh I see you are in the Malthus camp

The world's population will plateu as more countries develop... everywhere where prosperity and tranquility has spread, birth rates have dropped. The rate is so low in America and Europe that the size of the population is almost stagnant. When it hits 2.1 children per couple, then for intents and purposes the growth rate is zero barring immigration. I believe it was a UN report of some sort recently that placed the population nearer the end of this century at around 9Bn.

And why will the life-supporting capacity of the world reduce, barring a major melting of the polar caps? Then the British isles will again make wine, and Canada will grow its wheat further to the north, and so on. In fact, it may even be a positive thing for us humans, save the weather effects.

Actually, improvements in GM crops are a definate. Heck, we can get cotton to grow eight time faster and many plants double in size with nontoxic pesticides and get fish to grow twice as fast... It is quite simple really, countries that do not use them face having their economy crushed in the short run and risk starving their citizens in the long run. If stupid people hate GM crops or not, they will have them, or suffer for their psuedoscientific parinoia.

And you make water sound like its this reasource that is all gone when you draw out a certain volume from the ground... I agree that you can draw out too much, but water tables and surface water is replenished by the water cycle on our soaked little planet... and heeey, if it rains more from global warming, then there is more water. Maybe a little global warming is a good thing? It is even theorized that the industrial revolution averted an ice age.

And coal power is not the problem, its the burning of the coal that is the trouble. With a little calcium and oxygen, coal can be broken down to clean burning gasses, like carbon monoxide and hydrogen. Carbon sequestration is also quite possible and some methods are being tested right now. Throwing away 200 years of cheap energy right under our feet would be criminal.

And as for the developing world not getting enough reasources, well alot of the reasouces on this planet aren't being extracted because the demand isn't high enough. There is plenty of oil and gas, but the need for it isn't high enough or the technology easy enough to bother going to get it. Same deal with metals, which are largely recyclable.

Speaking of recycling, when demand for such materials is high enough, then it will be done more prevelently... one particular method of interest, Thermal Depolymerization, can injest most anything involving carbon and convert it to oil, gas, and its mineral byproducts (which make good fertilizer if you put in turkey guts).

There is enough raw material on this planet, its just a matter of using it... As our technology improves and economic pressure mounts, we will be able to do the same and more with less and less material.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#106 2004-06-18 18:32:21

Ian Flint
Member
From: Colorado
Registered: 2003-09-24
Posts: 437

Re: The Case Against Mars - Why Mars is not a good target!

Returning deuterium to Earth and selling it is a POSITIVE cash flow of millions.

Not if nobody'll buy it because it's basically already free to the people who want it (nuke reactor people) here on earth.

Let's see...the last market price for deuterium that I heard of was $10 million per tonne.  Sure, it's free if you use your nuke's power to make it, but why not just sell the electricity and make some money?
Let's say a certain reactor is running at max capacity and doesn't want to divert power to make more heavy water.  Just sell them the deuterium you have at half price.  The nuke owner would save money and also get a big PR boost by buying the first interplanetary import.

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#107 2004-06-18 19:10:37

Grypd
Member
From: Scotland, Europe
Registered: 2004-06-07
Posts: 1,879

Re: The Case Against Mars - Why Mars is not a good target!

GCNRevenger said

If stupid people hate GM crops or not, they will have them, or suffer for their pseudoscientific paranoia

Im sorry to say that people are stupid, who are they going to believe a man in a suit saying how great this genetically modified corn is, Or the large group of protestors shouting Frankenstien food, doom and gloom.
Well im sorry to say most people dont know enough about the subject to give informed opinion. Thats just the way it is, look what happened to the Nuclear Industry. It has been almost completely stopped from expansion by these type of protestors.

As for global warming it is the single biggest threat to mankind and that was a quote from the United Nations, Kofi Annan. As for Britain being able to grow grapes and wine, great, just means that most of southern france is a desert, I wonder where these people will go.

As for getting back a bit on topic, GM foods great we can develop crops that are more resistant to the harshness of the luna and martian frontiers. May even make money on it as all these protestors will know there is no chance for crops there to enter the earth biosphere. So now we have something else we can sell to earth, Knowledge of advanced farming technigues and crops that thrive on reduced amounts of water.


Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.

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#108 2004-06-18 19:24:06

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: The Case Against Mars - Why Mars is not a good target!

Yes people are, but when faced with the choice... either accept the superiority of GMOs or face shortage, I imagine they'll fall into line pretty quickly. Today, about 63% of Californians are open to talk of building new nuclear plants. France has shown the superiority of the nuclear power and the Envirowackos have failed to show the competitiveness of "green power."

And as for that idiot Kofi, I don't have a very high opionion of that lying, arogant weasily theif... oops being redundant again. The IPCC folks he bases his opinion on, the ones who wrote the Kyoto Protocol, have had the foundation of their report called into question by new data, better analyses, and one of their prime sources being a liar.

And then for the tin-foil-hat moment of the day, what would be the United Nations' ultimate answer to global warming? Global regulation and economic control of course! Imagine that... wannabe world government

---

About nuclear plants refining Deuterium: nuclear plants can only convert about 1/3rd to 1/2 of the heat produced by the reactor core into electricity, the rest is dumped as low-to-mid temperature coolant into other coolant loops (see big conic smoke stacks). This waste heat energy is enough to largely power a distilation plant or even perhaps a water-cracking Sulfur/Iodine Sabatier reactor (which has nothing to do with nuclear anything). So there isn't much or any loss of revenue for electricity if such a setup were designed.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#109 2004-06-18 19:57:54

Grypd
Member
From: Scotland, Europe
Registered: 2004-06-07
Posts: 1,879

Re: The Case Against Mars - Why Mars is not a good target!

Frankly Nuclear powerplants really are hard to start and to switch off producing electricity, If we could make another fuel ie cracking hydrogen out of the sea cheaply when the need for electricity elsewhere in the grid is not. It would be better for these electrical giants. Hydrogen will likely replace petroleoum as the next fuel for cars.

But the waste of a nuclear reactor is a problem, Fusion plants when made will produce a lot less radioactive waste. But if Lunar helium 3 is thrown into the mix this becomes a lot lot less. Also the reaction is not so damaging to the plants structure and this makes them last longer. When we can make fusion plants Nuclear plants will quickly be priced out of the market. And even using Lunar Helium 3, 2nd generation will have a competitive edge over the Deutrium plants.

Japan realizes this and they are one of the strongest bidders to house the next stage in mans attempt to create sustained fusion reactions. This is not alterism but research that Japan realizes is essential for it as a country, economic edge.

And Lunar helium 3 will be pound for pound the most expensive item that man makes or refines. It will not pay for Lunar bases on its own but will certainly pay for a good amount of it. There is also an incentive to go further out. Helium 3 is a very rare element on the moon as it is delivered through the solar wind and is absorbed by the regolith. This is not the case with the gas giants these monsters may well be the persian gulf of the fusion age.

One way to get to these giants will be to build great orbiters which go in big ellipses from the earth to the gas giants. Built of lunar material in the lagrange points these Arks will pick up crew and passengers when they get near the earth travel outwards drop colonists on mars, Pickup supplies. Carry on to the gas giants rotate mine crews drop off supplies and head back to earth where they deliver there cargo's of fusion fuel. Not too far fetched, certainly would solve all our problems for going to mars


Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.

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#110 2004-06-19 02:24:51

JimM
Member
From: England
Registered: 2004-04-11
Posts: 247

Re: The Case Against Mars - Why Mars is not a good target!

Thermal Depolymerization, can injest most anything involving carbon and convert it to oil, gas, and its mineral byproducts

If that's true, why not feed it CO2 from the atmosphere and solve the world's energy and (supposed) global warming problems at a stroke?.

I must say I'd not heard of Thermal Depolymerization until now. I googled it and came up with some ineresting references to, mostly in favor.

However there is something about TP that leaves me with a skeptical taste in my mouth. It tastes of perpetual motion machines as, if it operates as advertised it seems a clear contender for defying the Second Law of Thermodynamics(*)--like the CO2 scrubbers for coal, gas or oil powered electricity geneerating plants I heard tell of recently. These convenient devices are supposed to filter out all the CO2 in the exhaust gasses from power plants and turn them back into oxygen and soot, but have the obvious flaw that they require more energy to operate than the power plant in question produces, so if that energy is created by another carbohydrate-burning power plant the net effect is more CO2, not less. OTOH, if the energy used to drive the scrubber is renewable, why not just turn off the power plant? You'd have more CO2-free power for the grid that way, for a lot less hassle.

(*)The basic Law of the macro- (as opposed to quantum-) universe when considering any process is the Second Law of Thermodynamics, which states in in its simplest terms that in any process energy out can never equal or exceed energy in; in other words, no process can ever be 100% efficient. Any process that appears to defy the Second Law, either doesn't really defy it or doesn't work.

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#111 2004-06-19 03:19:31

smurf975
Member
From: Netherlands
Registered: 2004-05-30
Posts: 402
Website

Re: The Case Against Mars - Why Mars is not a good target!

the Second Law of Thermodynamics, which states in in its simplest terms that in any process energy out can never equal or exceed energy in; in other words, no process can ever be 100% efficient.

What about matter - antimatter? Well that is if you forget the energy it took to create the antimatter.

---
And yes, conventional power plants can be clean. The only exhaust will be water vapor. However the mining and transportation of the fuel is not clean. However it’s a lot cleaner then everyone using fossil fuel based machines instead of electric ones.

And it’s easier (cheaper) to switch from one kind of fuel to another for power plant in the power grid then all the individual machines upgrading to something else from whatever they were using as fuel. The machines get their electricity be it produced by fossil fuels, nuclear, hydrogen, solar, hydro, wind or burning garbage.

Take for example hybrid cars. Build them with a small fossil fuel tank, lets say 10 liters and the engine is quiet inefficient and does 1L/30KM. So if you would drive on only petrol you still could do 300 KM (186.4 miles). If there is a breakthrough in for example hydrogen energy you could benefit from it, as electricity that charges your car would become cheaper. You don’t have to upgrade / buy a new car. And to make matters even better make the fossil fuel burning engine run on biological diesel.

So I'm for an electrical age where everything runs on electricity and power producing companies supply electricity to the grid by whatever means that is acceptable by the countries laws. Of course you would phase it in like now from normal cars to hybrids and in the time being let battery technology improve. And don’t push it, as you will get a lot of inefficient situations.
---

Im sorry to say that people are stupid, who are they going to believe a man in a suit saying how great this genetically modified corn is, Or the large group of protestors shouting Frankenstien food, doom and gloom.

I can’t blame them, especially after the mad cow disease and all the hormones that are in meat or the breast milk vs powered milk cover-ups. I’m not saying anything; I will wait and see what time tells about these new products. Personally I'm for selective breeding or even crossing but messing with the genes is to much for me.
---

Water now that is the problem. It is water that will be or a prime contributor to most wars that will happen in the future. It is a finite resource is pure drinking water and it is easily damaged. Ground water in most african and middle eastern states is either at a low amount or polluted.

Actually water should not be a problem. See the post about terraforming the desserts. If the nations in question would invest in water purification plants they could manage. For example if the Middle Eastern countries can build huge pipelines and refineries for oil they can also build huge pipelines and refineries for seawater. It's just a matter of looking ahead for the respective governments.

Using history there was no commercial need for England to create colonies in the americas. But they did.

Not quiet true as a lot of immigrants came to the US to escape hunger, oppression, war and mass unemployment.

So there where soci-economic resouns to move to the new world but I can't see any soci-economic reasons for living in a cave on Mars. That as long they haven't found unobtanium on the Moon or Mars.


Waht? Tehr's a preveiw buottn?

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#112 2004-06-19 04:50:52

JimM
Member
From: England
Registered: 2004-04-11
Posts: 247

Re: The Case Against Mars - Why Mars is not a good target!

...the Second Law of Thermodynamics, which states in in its simplest terms that in any process energy out can never equal or exceed energy in; in other words, no process can ever be 100% efficient.

What about matter - antimatter?

When you quoted me as above, you did not also quote what I also said at the same time, namely that the Second Law is...

The basic Law of the macro- (as opposed to quantum-) universe

Matter/Antimatter reactions take place at the quantum scale where, among other oddities, strange things happen to time and the Second Law of Thermodynamics does not apply. The Second Law describes the physical effects of time on events at the macro world--the world we 'experience' every day.

Richard P Feynman, one of the greatest physicists of the modern age, Nobel Prize-winner, participant in the Manhattan Project, only member of the Rogers Commission to reveal what really went wrong with  Challenger and an early advocate of nanotechnology, once pointed out that antimatter particles (for example, an antielectron) can be described entirely in terms of equivalent matter particles (for example, an electron) that are moving backwards through time.

Make of that what you will.

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#113 2004-06-19 09:11:30

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: The Case Against Mars - Why Mars is not a good target!

Thermal Depolymerization, can injest most anything involving carbon and convert it to oil, gas, and its mineral byproducts

If that's true, why not feed it CO2 from the atmosphere and solve the world's energy and (supposed) global warming problems at a stroke?.

However there is something about TP that leaves me with a skeptical taste in my mouth... Second Law of Thermodynamics, which states in in its simplest terms that in any process energy out can never equal or exceed energy in

Ah! Well let me put your mind to rest and get my chemistry on... TDP is, as the name says, designed to digest polymers which constitute a great deal of our trash and waste. When I said "most anything of carbon" that is because alot of our trash is polymeric. Oil is simply a chain of carbon atoms of intermediate length with hydrogen atoms along its length, natural gas is likewise except much shorter chains, and polymers are extremely long chains (100's of atoms) of carbon with a little oxygen and nitrogen in some cases.

When you heat a polymer under the appropriate conditions, the extremely long chain will break down into smaller ones (oil, gas) at the expense of some energy, which would itself make the process uneconomical; the trick is to use the natural gas produced to make the heat for the next batch to break it down and so on.

This isn't a perpetual motion machine, as the quantity of chemical energy stored in the polymer feedstock is greater then that which you can derive from the product fuels, if you consider the "free" oxygen you get for combustion from the air.

It cannot process carbon dioxide which has no hydrogen and isn't a polymer, but it would save having to pump some of our oil out of the ground and save alot of trash volume, since so many things are polymers...

-Old tires, plastic pipes, perhaps lumber (polyisoprene, biopolymers)
-Living tissues ("meat," biopolymer)
-Your clothes (PET & cotton biopolymer)
-Most household items (plastic bags, plastic forks, cardboard biopolymer)
-Old carpets
-Some farm wastes (corn husks, wheat stalks, chicken guts)
-Sewage (biopolymers)
-Annoying people you don't like

The process is pretty simple, the trouble is the machinery to do it on any scale is quite expensive... inorganic materials put into the machine can be removed pretty easily by distilation or filtration, and for the few carbon atoms that don't have enough hydrogen to saturate them from the polymer are left over as carbon black.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#114 2004-06-19 10:20:58

dicktice
Member
From: Nova Scotia, Canada
Registered: 2002-11-01
Posts: 1,764

Re: The Case Against Mars - Why Mars is not a good target!

Regarding hybrid cars: I've said it before, and I'll say it again--forget about better mileage since that's a given. Why don't you mention the advantages of no idling in traffic, and extrapolate the benefits of that for every big city on Earth in the short run?

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#115 2004-06-19 10:24:37

smurf975
Member
From: Netherlands
Registered: 2004-05-30
Posts: 402
Website

Re: The Case Against Mars - Why Mars is not a good target!

Regarding hybrid cars: I've said it before, and I'll say it again--forget about better mileage since that's a given. Why don't you mention the advantages of no idling in traffic, and extrapolate the benefits of that for every big city on Earth in the short run?

Well a lot of people (if not most) think with their wallet and not their conscience.


Waht? Tehr's a preveiw buottn?

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#116 2004-06-19 10:56:47

Grypd
Member
From: Scotland, Europe
Registered: 2004-06-07
Posts: 1,879

Re: The Case Against Mars - Why Mars is not a good target!

People do not necessarily think with there wallets all the time. In an american city how many SUV's do you see. Well these are not for going into the wilds of that country, No its just "cool" to be seen in one.

for those not in the know SUV= Sports Utility Vehicles (4x4's)

And when fuel prices go up these are some of the people who scream the loudest as this vehicle type tend to be one of the biggest gas guzzlers.


Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.

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#117 2004-06-19 17:49:25

MarsDog
Member
From: vancouver canada
Registered: 2004-03-24
Posts: 852

Re: The Case Against Mars - Why Mars is not a good target!

In the beginning, Mars wont have SUV dominated traffic jams.
And when they do, it will be steel wheeled and battery/solar cell powered ?
-
I can see that traffic jams are motivating people to emigrate to Mars.

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#118 2004-06-19 20:10:55

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: The Case Against Mars - Why Mars is not a good target!

Cities on Mars, if you wish to call them that, will not be at all like an Earth city for the forseeable future...

They will be much smaller for a comperable population, pressurized & heated shirtsleeve volume will be at a great premium, and since coming/going from a little Hab module of your own away from the city would be too much trouble, everyone will live and work close to the city... There won't be a need for cars, since most everything will be within a short walk or a little tram ride. Nobody will have "houses" persay anymore, and businesses will be close by as well. Trains out to agriculture domes or various factories will also be the most likly mode of transportation for farmers and builders... They will closer resemble a college campus or a military base than a "city" as we traditionally think of them.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#119 2004-06-19 21:41:34

MarsDog
Member
From: vancouver canada
Registered: 2004-03-24
Posts: 852

Re: The Case Against Mars - Why Mars is not a good target!

Workers in large cities commute to get away from the problems of downtown. People on Mars will get along better and will want to be closer to each other than on Earth.
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They might live closely, similar to a large subway station complex, shopping and entertainment at the bottom, residences on higher levels, and enclosed with a dome on the top. Once structural materials are manufactured on Mars, it wont be long till everyone has comfortable space such as a 1 bedroom apartment. Their priority will be to manufacture, build and expand.

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#120 2004-06-19 21:57:00

Timeslicer
Member
From: Arizona
Registered: 2004-06-19
Posts: 27

Re: The Case Against Mars - Why Mars is not a good target!

Setting aside Mars for the moment, how does one make ANYTHING in space economical?

Satellites already are economically valuable.  Built from there.

Make them cheaper to launch and maintain, and more will be used.

I think the next step up is a solar powered space tug / robot.  It can re-boost satellites, and transport supplies (coolant, fuel, etc) from whatever orbit is least expensive to launch into out to rendezvous with any satellite.  It can also deliver satellites from LEO to GEO. 

Once they're up there, new satellites will be designed to make good use of them - i.e. they'll become dependent upon them, and as a result be cheaper.   Likely they'll be designed more and more to allow the robot to service them - replacing malfunctioning modules.

The next step beyond that might be to optimize use of the robots' time - establishing a supply depot in high orbit, where supplies can be delivered in advance of need, using whatever launch strategy works best - probably launching large quantities of commonly needed supplies to LEO, and letting the tug-bot slowly haul it up.  This will enable faster service to satellites on demand - but will probably require another tug-bot so one can be ready to dispatch while the other is towing supplies to the depot.   

This will make GEOsynch satellites substantially cheaper, allowing increased use of those - and needing more tugs because it'll take quite a while to cycle up from LEO to GEO.

The depot and tugs will make other robotic missions more economical.  Many of these will be science craft, but a few may do things like investigate asteroid mining.   

Note that I haven't mentioned humans going into space.   Frankly that isn't economical yet.  But we'll be sending some out anyhow, for exploration and national prestige, and the supply depot could be quite useful for them as well.   I'd guess that using the tug to deliver 90% of the mass for a lunar mission from LEO to GEO would cut human mission costs by as much as 2/3rds.

Mars?  Well, if we're going anyhow, the space tug and depot will help keep costs down.  We've got a LONG way to build out into space before it become economical to go there, but getting costs down is a helpful step.

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#121 2004-06-19 23:06:28

MarsDog
Member
From: vancouver canada
Registered: 2004-03-24
Posts: 852

Re: The Case Against Mars - Why Mars is not a good target!

The economies of scale would enable us to set up stations, at the Lagrange Points, to the rest of the solar system. Wont be as risky as direct to Mars.
-
I wonder if an alternate to rocket launch will ever be possible;
such as a space elevator, or an artificial mountain reaching above the atmosphere.

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#122 2004-06-20 06:39:11

Grypd
Member
From: Scotland, Europe
Registered: 2004-06-07
Posts: 1,879

Re: The Case Against Mars - Why Mars is not a good target!

Yes, a space tug will be a commercial possibility.

At the moment there is a fierce competition for the prized geo and leo orbits. Space also has a lot of excess junk from orbit operations just floating. A space tug that can deorbit the used switched off satelites and frees there slots as well as reducing space junk is a necessity.

Space junk is a problem now it damages the solar panels of satelites and stations in space and in one case nearly caused the shuttle to suffer a window destroyed with the possibility of explosive decompression. It is taking too long for this stuff to deorbit itself, naturally.

A space tug can be a commercial success as space insurers ie Lloyds will make the satelite using companies, pay for its services and reward with reduced insurance costs. But a space tug that is supplied from resources other than the earths will be at a reduced cost.

When we set up the first lunar base it will not be for profit but science, we cannot get around that, but the applications that the base discovers. Will allow us to find a profit. It will allow us to support other operations ie asteroid mining, orbital manufacturing, Space tug operations.

We need that first footstep or else we will never get off this planet, in any meaningful way.


Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.

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#123 2004-06-20 07:17:53

smurf975
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From: Netherlands
Registered: 2004-05-30
Posts: 402
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Re: The Case Against Mars - Why Mars is not a good target!

I wonder if an alternate to rocket launch will ever be possible;
such as a space elevator, or an artificial mountain reaching above the atmosphere.

I don't think a mountain would do good as the base of such a mountain will be huge and the earth needed to construct it even huger.

However I was thinking of a space plane that has multiple kinds of engines.

It takes of from any airport and accelerates using a “normal” jet engine and reaches critical speed. Then the scramjet kicks in and takes it further until it reaches a height were there is not enough oxygen. Finally the rocket engine is kicked in and takes it to the final destination.

The stage from jet engine to scramjet could be done by using two engines that use the same air inlet and outlet. However at a certain speed the air inlet is diverted from the turbine to the ramjet using an automatic valve that closes or opens the inlet of the respective engines at a certain air pressure/speed.

Reentering Earth atmosphere it should have enough speed to go on without the scramjet. As soon as it is at a certain speed the jet engines kick in and you can fly the plane to any destination you want as you would a commercial airliner.


Waht? Tehr's a preveiw buottn?

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#124 2004-06-20 07:24:26

Ian Flint
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From: Colorado
Registered: 2003-09-24
Posts: 437

Re: The Case Against Mars - Why Mars is not a good target!

As long as we're talking about making Moon bases profitable...

A company can set up a telescopic array on the far side of the Moon and then sell the pictures, data, viewing time, etc. to anyone.  The prime customers would be universities, I suppose.

I know of at least one company that sells high resolution satellite imagery to the public.  I assume that it is 100% privately funded.  If that's true then this could also work on the Moon.

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#125 2004-06-20 11:06:42

smurf975
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From: Netherlands
Registered: 2004-05-30
Posts: 402
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Re: The Case Against Mars - Why Mars is not a good target!

To follow up it looks like that NASA already thought of the tripple engine design.

Its called the Turbine Based Combined Cycle (TBCC). Got it from this http://www.affordablespaceflight.com/nasa2.html]webpage

A quote:

Turbine Based Combined Cycle (TBCC)
TBCC as it is usually defined, is very similar to the TRCC concept we just covered in that it has turbine engines and a ramjet-scramjet, but it does not normally have ducted rockets, and the turbine engines do not have afterburners.

The main difference TBCC and TRCC is that TBCC uses the turbine engines to create an ejector effect with the ramjet which has the potential of improving the ramjet's performance in the zero to Mach 2.5 speed range.

Since TBCC is usually looked at as a propulsion system for a Mach 5 to 8 aircraft and is not expected to be capable of going faster then Mach 8, we will investigate adding either rockets or ducted rockets to the system in order to increase its top speed.


TBCC
This chart shows the range of possible engine operating modes that are possible with this type of propulsion system.

As shown, this vehicle takes-off and accelerates to approximately Mach 2.5 using the turbines and the ramjet. One of the options with this propulsion system is what fuel to use for the ramjet during this portion of the flight profile (hydrocarbon or liquid hydrogen) and what velocity is optimum for the transition to liquid hydrogen if hydrocarbon is used.

At Mach 2.5 the turbofans are shutdown and the vehicle continues to accelerate using only the ramjet-scramjet.

Somewhere between Mach 8 and Mach 10 the rocket motors are ignited with liquid oxygen and liquid hydrogen. The vehicle then continues to accelerate using both the scramjet and the rocket to somewhere between Mach 14 and Mach 18 when both are shutdown. The vehicle will then coast up to its staging altitude of 150 km where the payload with expendable upper stage is released.


Waht? Tehr's a preveiw buottn?

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