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Hi,
About polar orbit penalty, go to this site:
http://www.spaceandtech.com/spacedata/e … pecs.shtml where you'll find a comparaison of payload from a 11? orbit (12000) to a 90? orbit (polar) for a launcher (9200). So, it is 25%, I added some loss for the 0? to 11? if we suppose we arrive on an equatorial orbit. This is for Earth, I don't now about Mars, but we can suppose that it could be about the same ratios.
The important thing is that there is a big loss and that because you need fuel to correct the orbit around Mars, you need more fuel from Earth... Have to recalculate all the weights of the mission.
About the poor's mission, I think that the most expensive thing in Mars mission is design of vehicles and processes. When the design is done, build the rockets, vehicles, chemical plants is not expensive. In Zubrin's plans, I think that 50% is for design, 25% for the build and 25% for the launches from Earth, and the design cost is the same if you have 2, 4 or 24 people in your mission and it is the same if you land on equator or on poles. The difference from your plans with his plans is that you go, walk and forget, so you use less vehicles and launchers. This is why I don't think your plan is so good as a poor's mission. But it is good as a part of a colonization because it will be easier and more efficient to get water and CO2 and solar energy from the poles. And to take it back to the main base on equator or in fuel tanks on orbit.
The best way is that when the design is done, take a mission to each pole and work continuously with automated systems, and send a crew at spring to restart the plant and at fall to stop it...
I think we should explore:
- meteo at poles: if a 6 months dust storm stop the plant production because solar panels are 90% less efficient in the storm, what to do...
- automated systems to get and process CO2 and water
- transportation of final products to orbit gas station or another base.
...
From these, we could now if it is possible, usefull and economically efficient.
CC
Hi Crossman,
From my readings about pole delta vee penalty is about 35/45%, that mean that with the same amount of fuel, you get 35/45% less cargo to polar orbit and the same when you go back to go from polar to equatorial orbit...
About pole missions, I think the main problem on Mars is that the ground could be really dangerous, with 'cracks' (I miss the word, I hope you'll understand) on the floor, and, as you say, very thick CO2 ice that will blow up while your rockets fire to land your vehicle, and the problem that any thing you use which heat will be dangerous in this place...
And all the other problems you talked about...
It is maybe better to land at the limit of the ice, reducing risks, and to extend pipes to the ice to use it. It is easy to get gazeous CO2 by covering floor with a black plastic sheet and pump the gaz from under the plastic....
For the time the crew have to stay in space, they can work on Phobos to set up a plant at the beginning of the mission and take products at the end. But since Phobos can produce the same products (fuel) that you'll get on the Mars poles, a Mars pole mission is maybe not usefull at short term.
All this said, I think it's better to land on equator and use a small nuclear reactor to get a continuous power.
Maybe others will think different, but the question will be to find volunteers to go there... I'm not.
CC
I'd just like to tell that people who youngs have babies at 12 were usually people where life duration was 24 years. So 12 is half of the life and I remember in France an story about a queen who met a witch because she had no baby and she was 12 years old. And she died at 24. So age when you have child depend of the time you life will last. Islam rules were edicted in 432 of JC era and at that time, they didn't live a long time. The problem is that they law only slowly change when the world change. Probably in 20 years, they will change the law to forbid marriages before 20?
About Mars, people will spend most of the time in shielded spaces (station, caves...) so this should not be a problem. They will have all the technologies needed to mesure the radiation people get and to say if exists risks for babies. This is what our health services are supposed to already do. I hope we will get the same services or better on Mars.
A bigger question is about low gravity and its consequences on foetus growth.
CC
Hello,
why to speak about what could not work (GPS, inertial, satellites...)?
If we put six GPS sats around Mars, we should put telescopes too inside for meteo and other needs and radio transmettors and relays.
If GPS fails, it exists micro accelerometers that a small processor can control to extract exact position. It weight only grams...
If those two systems fails, I think this means you already ar in big troubles... But if this happen, just turn you radio set on and cry...
CC
Hi,
yes, I forgot the vector so the speed should be a bit bigger for 1G.
Thank you shaun to have see that.
Bill, don't care about coriolis effect, someone made experiments and found that at the speed I calculated, there is no bad effect on common people. In fact, for most of people, even if they turn 3 times faster, they will not feel anything.
It is true that radiation shielding is the biggest problem in this project but if you do this in a tunnel.
CC
Yes, and after the last country is done, Mars is empty because they don't plan to let poeple there for more than one rotation (2 years)...
This is like the moon, come, have a (long) seeing, and forget...
Sorry, I don't trust them.
CC
Hi,
even if I said this thread could be dead because the same topics are discussed on another thread, I'd like to give a 'pro' word to the idea of a permanent Mars orbital station.
Why ?
Because all the modules sent to the Mars surface will be pushed from Earth with some rocket. These one will probably have solar panel, tanks... So just have to add an hab module and connect it to all these power suppliers and get a permanent space station. It could be helpfull for moons exploitation and space fuel services.
But this could be a 'second mission' program since first, we have to be sure life is possible on Mars.
I will think about this too. (I am writing a big program for Mars colonization with friends...)
CC
Hi,
I was not here for a while, so I give a lot of answers.
First to RobertDyck for his answer to mu post of Sept 5 22:10
1 You said Energia has a payload of 22 tons to orbit. I was to the site you indicated and read this:
for The Launcher Energia (of Buran)
LEO Payload: 88,000 kg. to: 200 km
GEO Transfert Orbit Payload: 22 000.
So it is 88 tons to Low Earth orbit. I said 100 tons, but it was from an english site so maybe imperial tons ?
2 Energia M never flight, but is made from 'standard' systems, so I am confident it should flight correctly for 130 metric tons on LEO.
3 From my informations, Angara 5 never flight.
Robs I am sorry, but your scenarii are not usefl since Energia really launches 88 tons on LEO.
And to all of you, don't care about what you now or not know, every one has to give to a Mars project, even if you just know how to do good food, you are usefull. I'd not like to go to Mars and eat synthtic food for 3 years...
CC
Robert, do you know anything about big Angara, since my info are that only the smaller versions are available for now!!!
I know that Energia M lost the contract, but the design was done and 'on paper' tested. Using 'standard' componants, it seems good enough for me to pay the development.
In fact, I don't know if we need 50% more than standard LV Energia since I don't the weight of the needed payloads.
CC
Bill, I try to calculate:
acceleration = speed? (in rad/sec) * R (rayon in meters)
For your example:
acceleration = 0.7 * 9.81 m/s?
R = 1000 m / 2 PI = 160 m
to find speed = SQR(a/R) = 0.207 rad/s
since your tub is 1 km long, speed = (1000/ 2 PI) * 0.207 = 32.94 m/s = 120 km/h = 2,3 rpm (revolution per minutes)
So it is possible. Since the tunnel has vacuum, the energy needed for each vehicle should be some 75-100KWh (it's a big car running at constant speed with no drag (air oposition to movment).
The real problem is to build it... It seems easier to create a circular inclined road and put two rails on it to guide electric car(s). But radiation shield? Maybe it is cheaper at 'short' terms to use eavier shielded vehicles than to make an underground tube.
The idea seems very clever. But for now, we don't even know if 0.38 G is dangerous for humans beings. But I think that if we want to do babies on Mars (in a 'far' future), this kind of system could be used to 'train' the baby in utero for the 1 G for better development and maybe for wounded people (I saw somewhere that wounded people could be better in low G because less efforts on muscle and less blood losses, but 1 G could be better during convalescence).
This idea is to keep in our mind for a needed system on Mars ground if colonisation becomes a fact.
Thank you for this Bill.
CC
P.S. My english is not perfect so forgive miswritings.
Phobos, the problem with emitting satellites is the smaller the recepter (the pocket GPS), the bigger the emettor (sat)...
And to get 'less' satelites, have to be higher in space so the square root acts to reduce again your efficiency so you need to increase power.
But, all is not lost, the ideas I gave could save GPS on Mars...
CC
Phobos, as said on another thread, we can do it on the Mars floor cheaper.
Maybe this thread is dead ?
CC
Phobos 'If we want to trim the fat I say we start with the D.o.D. first.', I fully agree (but for now they increased 50% in last 3 months).
But increase NASA efficiency is an important goal too.
CC
Super super super, i buy...
CC
Hi Phobos, do you think it cheaper to design a 600 T rocket or to use 5 existant rockets?
Mars direct needs a very big unknown (from me) rocket...
And every body speak about redundancy I think about redundancies in the crew too, so I say we need 24 people to recreate a 'society' with more interactions than in a 6 crew. I said and repeat we can use 3 or 4 energia to land 100 tons (a haband ISPP landed softly, and freigh (food, spare parts and material) landed roughly) on Mars than to energia to put a 40 tons vehicle and 100 ton fuel to send crew to Mars.
I did not really calculate about 40 tons and 100 tons so I am ready to speak about it.
I just made a post on another thread about a new possible kind of thruster (50% Nuke like 50% plasma like but with no nuke nor plasma) with a possible Isp of 1200 which could make my idea easy.
Other thing, 4 'simple' loosable missions plus one 'non loosable' would be better than one complicated 'non loosable' one.
Think about it...
CC
Hi, John_Frazer, I come back on your posts. You speak about 3.5 years in 0 or 0.38G. I'd like to reply that you spend 8 hours per day at 0G when you sleep, long term hospitalized people are also at 0G. in France there was a study about low G simulation, it consisted to keep people horizontal (in fact head a bit under feet) for 3 months. This said, we could do the reverse on Mars: let people sleep not horizontally but with head higher than feet to make their heart work longer. I agree that will not fully compensate for lower Gs, but it's better than nothing. Next point, when this people work outside the hab, they will carry 50Kg (heavy wears and air recycling for hours, radio, water and food, batteries...) equipment, big enough so they make some sport.
Info now for RobertDyck, Phobos and others, RKK Energia (the company) had a project included in Energia (the rocket) design: Energia-M which is supposed to put 120(/150?) metric tons on circular orbit at 200Km. This special design seems 'simple' so, for me, it should be faster to validate than the shuttle C (because the design of the main tank of Energia is 'solid' and can carry more than the 'light' design of shuttle's).
For the end, I am now thinking on a kind of thruster using thermal solar power (instead of electric solar) to make energy on the Mars space vehicle and at the same time, give thrust. We could obtain an Isp of (from basic calculations) 1200 instead of 950 for NTR with less risk and less weight (5 tons I hope + fuel).
The concept is: concentrate the sun on a heater to obtain a 2500?C gaz, use part of it to run a turbin to gain electric power, to ionize the rest of the gaz, then guide and heat this ionized gaz in a pipe where sun light is concentrated (like a kind of 30 MW 'laser'), so we don't need a material to resist the 4000?C I hope we could obtain. Fluid could be H2O, if 2500?C can break it (with a catalyst) in O2 and H2, and obtain more gaz than with H2O.
If this could work, we need less than 100 ton of fuel for 100 tons on Mars orbit (instead of approx 250 for 100 with LOX/LH).
This is for now 'utopic' since I can't test this, but the idea is now 'on the air' so I hope someone can make some calculation on it (for example, we need a 200*200 mirror to obtain 50 MW thermal) and the goal it to get some 10 MW electric and 40 MW thermal concentrated in a small pipe to heat the ionised pipe.
If someone is interrested to speak about this, tell me.
CC
Hi Bill and all,
I didn't find info about carbonyl energetic budget. It seem to work at low temperature, so I wonder why Earth industry don't use this way to extract iron. Is there any (hidden) draw back?
CC
Hi RobertDyck,
Just to say that I also said that before to send a crew, I will send 100 tons freight on Mars in automatic vehicles using a slow trajectory, a vehicle on Mars orbit for the descent/ascent... So the vehicle with 20 people in has just to carry people and food for 6+6 months.
Fuel to come back to Earth can come from in situ fuel synthesys.
For this, I think we could use a NTR or Solar thermal rocket with an Isp of 800/1000 so 100 tons fuel for 100 tons on mars orbit.
CC
I agree with Phobos (but why a space station ?), I really think 0.38G is enough for people, I think they could sleep not horizontally but with feet lower than head so the heart have to work more and the blood stays more in the legs to compensate for lower gravity.
It is not difficult if needed to do a small (rotating) accelerator to simulate 1 G where 2 or 4 people could sleep 8 hours every week. 2 or 4 boxes on 1 or 2 arms doing a cross, a motor at the crossing point to do this turn, and this needs far less energy than to send people on Mars Orbit.
Robs, I agree with the theory, but how do you find meteorit ? You need time (remember in earth deserts how any meteorits are rare?) to travel the place and energy to move your rover and for the magnet. After, you need energy to create iron carbonyl to be molded and again energy to bake it. Did you count how much energy per kilo of finished product?
I come back to my point: if you want to mine or refine metals on Mars, first you need a LOT of energy...
For info: in best foundries, energy cost to melt 1 kg of refined iron is 960W (in batch of 1 metric tons).
CC
Hello everybody,
just to answer to RobertDyck who said:
I haven't heard of anyone developing a breeder reactor that recycles the fast-and-hots.
It is French SuperPhenix reactor which was first done to create more radioactive elements than it uses by converting U238 in U235. After the 'greens' said we don't need uranium for future, they wanted to modify it to 'burn' the wastes folowing theses steps:
Make fuel rods with the worse waste (very radioactive/long life), irradiate (atoms will be broken by neutrons to create new smaller atoms) them to create other waste, but these ones are partially low radioactive or 'short life'. Sort the waste to purify the remaining worse waste and do again... After testing in SuperPhenix, we hoped it would be possible to do the same in standard nuclear plant (but with lower quantities).
But the 'greens' said we don't need to clean uranium too, so we have now a lot of waste that 'greens' don't want in their garden... The same kind of problems in US?
Isn't there something wrong in their brain ?
And I think SuperPhenix used Sodium cooling, but it is very dangerous since sodium burns in air.
To Phobos:
I didn't read the book but I saw the Zubrin's program explainations on several sites. I do agree with the quality of this for a 'low' budget mission but it's a lot of 'one shots', not a real colonisation project. The comments I gave before are about Russian program.
I explained somewhere else on that site what I think a program should be: Several slow heavy loads to Mars with freight before sending the crew, faster travel with a big crew(20-24) to Mars, only one big station at the beginning and possibility for part (or all) of the crew to stay more than 1.5 years. So I don't really trust the Mars Direct concept, I prefer some orbit rendezvous to get better weight/fuel ratios.
And I would be very happy that someone really want to do a really ambitious space program whereever it comes from.
CC
Hi Robs,
if you take a Nuclear Power with you (my #2 suggestion) , why don't you use electricity to run your car ? It is more efficient by a factor of 2 or 3.
Or maybe you take a small one which needs 24 hours work to give only some hours autonomy ?
CC
Hi, CM,
you seem to know what you speak about, so i agree with you. The only point i maintain is that it is not easy to obtain shaped (forms ?) or flat plastic from simple machines. I saw the complex machines sold in France for this purpose... I hope you could find simple ones.
CC
Hello,
GPS satellites are big: 1816Kg and are on 20200 km circular orbit (12 hours) inclined at 55 or 63? and need 710 W, they were designed for 7.5 years life time, but most of those launches in 90 are always working.
If we want to use equivalent parameters around Mars, they should be on a lower orbit (7000 km?) to achieve the same 12 hours orbit, so they should need less power (since I don't know how much power the emettors uses, I will just guess near to 400W, so the same solar panels could be enough).
The Earth GPS use 24 satelites, but I think a minimum of 6 is needed for a minimum service. The problem with GPS is it need several ground stations to work...
Common life span of satellites around Earth is 7/12 years but it should be less around Mars since there is no Van Allen belt around Mars so maybe we need more shielding.
I think NASA is planning to send some GPS (or equivalent systems) to Mars with their internet network.
Conclusion: if NASA doesn't send a GPS like system around Mars, we should have to set one, but because of the complex design of the Earth GPS, it could be needed to design a simpler (less accurate) system to reduce costs (satelites are too heavy and need several ground stations). I guess synchronisation based on far star (or sun) position with 'top' transmitted from one to the others satelites could be less expensive and use of discontinuous localization (all the sats send a one second burst every 5 or 10 seconds) could dramatically reduce power needed while maintaining a good accuracy for 'slow' vehicles. All this to try to obtain the same weigh than a globalstar (400 Kg) and a low power consumption.
CC
Infos on rockets, constellations, companies can be found on:
www.spaceandtech.com
Hello Cindy,
Very clever question!!!
And while we test the crew, why don't test the Mars Hab ?
I think Mars project will last a few years before anyone goes to Mars. So Mars Hab, rover and other stuff will be ready long before the crew go to Mars.
I think that after the standard selection (Psys, technical tests, health tests...), the Mars station could be built in a cold desert (a cold place were it never rains like altiplano in South America) and teams could live there simulating life on Mars for long periods. We could even set phone lines with 4-20 minutes delays to simulate communication with Earth.
This crew could test the green house, vehicles, hab usability...
I think each test could last 3 months. The advantages are to check systems, their interfaces to users and crew ability to live together and 'slow' communication consequences (with Earth) when facing problems. It also covers problems with air regenerators, energy systems, diet of the crew (what they eat, drink... and blood check-ups). Even if this is done in 1G gravity.
Each crew could test variations on the systems to select the best ones. And different crews could be check too.
When 2 crews are selected, they could spend a longer time in the simulation hab (6 months ?) to get a perfect knowledge of all the systems.
I say this because in Mars Direct or other scenarii, a first version of the systems is sent to Mars as backup and we need (i think) at least 3 years for that to be done. 3 years we could use for crew selection and training.
And because there will be problems with this training, we can know how good are the psys of the crews and if it is possible to ease a problems through radio communications (with the big delays).
CC
Hello BGD,
1 and 3) this plan will not exist for a while because the things (bacterias, small mining machines...) you are talking about does not exists on Earth but in labs. More problems, these bacterias needs heat to work and so, there are better ways to do the job. About mining machines, they often break or doesn't work so good... To mine on Mars, the first thing is to have energy (a lot) so we have first to do a real big station.
I think that even if people can come back, we should be able to allow some of those who will go to Mars to stay there more thant the first 18 month mission. If this is possible, the number of the crew on Mars could increase with time and and become big enough to think about mining. The first mission should have 'raw' metal, plastic... and machines to work on them so people can 'react' to problems easily.
We are not so good with genetics now, wait 20 or 30 years more and maybe it will be good. For now, I think we could simulate a 'green house on Mars' environment (cold, less light...) on Earth and seed plants and 'select' the survivors.
2) About encyclopedia, you are right, it could be a good project to sum all the human knowledge in an encyclopedia. But it will be really huge (hundreds of gigabytes I guess).
About using our knowledge on Mars, think in most of domains, Earth knowledge can't be used on Mars because the environment is not the same and 'backgroung industry' does not exist. For example, make an electronic chip needs ultra pure water, silicium, aluminium, gold, germanium (and others), electronic design software, ultra vacuum,very big and special deflectors (to concentrate light:UV on a small area)... The last plant create by IBM costs billions of dollars, so, don't even dream about this.
The only way is to rethink every processes on Mars and to buy parts from Earth, assemble in space or on Mars and to sell to Earth. This is called commerce. The point is to find something to sell (water for rockets propulsion, metal, food 'made on Mars'...
I think, here, every one hope this will hapen one day...
But don't stop to imagine and dream...
CC