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B Moon base

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  1. May 21, 2016 #1
    Following scenario:

    1) Send a few rockets with large payloads to the moon, carrying various parts of a nuclear reactor to be assembled on the moon

    2) Use the nuclear reactor to extract oxygen from various materials found on the moon

    3) Use the power of the reactor to harvest resources for building more infrastructure

    Why hasn't it been done already? Which of those steps is beyond our means?

    It seems that it would be the most reasonable step to do, before any other steps when considering to further space exploration. Without any atmosphere and with only a fraction of the gravity earth has, one could easily build spaceships with materials on the moon and then use a mass driver to get them into orbit.
    So what exactly stopped us for so many years?
     
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  3. May 21, 2016 #2

    davenn

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    The huge cost
     
  4. May 21, 2016 #3

    SteamKing

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    For one thing, the staggering cost of what you propose.

    Sure, it's easy to say, "Send a few rockets to the moon with large payloads. Let it be written; let it been done," like some sort of 21st century Pharaoh, but it's not quite as easy to call up the Russians, the ESA, or NASA like you were ordering take-out and have these rockets magically appear.

    Here is what amounts to a price list for sending stuff into orbit around the earth using different rockets:

    http://space.stackexchange.com/ques...nt-cost-per-kg-to-send-something-into-gso-geo

    This is a statement from NASA on their long-term goals relative to the cost of putting stuff into low earth orbit (LEO), not to mention sending stuff on to the moon:

    http://www.nasa.gov/centers/marshall/news/background/facts/astp.html_prt.htm

    The much ballyhooed Space-X rocket is intended to bring the cost of putting stuff into LEO to below $1000 per pound.

    Now I don't pretend to know how many pounds a nuclear reactor weighs, but even at $1000 a pound, that's going to be some expensive reactor, and these things aren't cheap on earth, where they don't need to use rockets to build them.

    It's unclear how much additional money would be required to send stuff already in earth orbit on to the moon and land it on the lunar surface, but I'm sure it would make the cost of the Apollo project from half a century ago seem like nothing.

    And for every pound of finished reactor or moon base or whatever, how many pounds of equipment and supplies must be sent to the moon, and we're not talking people here, to use in construction? The zeroes keep piling onto the end of the cost figure. You couldn't print money fast enough to keep up. Even the Chinese would find this project daunting, and they've been pretty good at sucking up loose cash worldwide in recent years.
     
  5. May 21, 2016 #4
    How is the cost huge compared to always resupplying the space station or launching satellites/telescopes from earth into space when all this could be built straight on the moon once you have your nuclear power plant up and running.
    We have hundreds of nuclear submarines in the sea, their reactors weighting around 500-1000 tonnes estimated. That would be about 5-10 missions to the moon to carry that weight of the disassembled reactor.
     
  6. May 21, 2016 #5
    Nuclear submarine reactors weight 500-1000 tonnes and they weren't really built for being super light. So that would be around 2 million USD for 1 tonne according to your values and around 2 billions for 1000 tonnes. 2 billions is nothing for nations like the US, let alone if this would be an international project. A full scale nuclear power plants costs over 10 billions to build on earth but i guess those would weight a lot more.
    So no, i cannot see how it is the cost of getting the materials to the moon. Even if it was 1 trillion, considering an international effort, it would be affordable still.

    The nuclear submarine reactors can deliver around 40MW which is not little. Good enough to get you going and maybe use that power to extract resources and build arrays of solar collectors etc and maybe even another nuclear reactor at some point starting from just raw materials found on the moon. The idea is to get just enough onto the moon to allow you and build EVERYTHING from scratch on there. First of all, the machines that build the machines from raw materials.
    Only the best engineers/physicists etc could achieve this i guess.
     
  7. May 21, 2016 #6

    SteamKing

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    The Saturn V rocket used to send astronauts to the moon could put about 120 tonnes into earth orbit. That does not mean that all 120 tonnes in earth orbit arrived at the moon, only about 45 tonnes, which included the Apollo command/service module, the lunar lander, and whatever incidental equipment was needed on the lunar surface.

    https://en.wikipedia.org/wiki/Saturn_V

    The Apollo command/service module had a payload capacity of about 1 tonne, which includes the 3 astronauts and their supplies for a mission lasting no more than 14 days:

    https://en.wikipedia.org/wiki/Apollo_Command/Service_Module

    So, assuming that you could use a rocket like the Saturn V to send stuff to the moon, it would take at least 500 launches just to get the reactor parts there, not including any other equipment or supplies. The inflation adjusted launch cost would be about $700 million per trip, so say $350 billion to fly one reactor to the moon, COD. Some assembly required after all the pieces get there, however.

    Now $350 billion may not seem like a lot of money, but governments do not exist to save money, they exist to spend it, and they are quite good at it. Currently, the U.S. government, which is the most awesome spending machine ever devised by man, spends about $4 trillion a year, but it takes in less than $3 trillion in revenue (called taxes) and borrows the rest.

    https://en.wikipedia.org/wiki/2013_United_States_federal_budget

    The total federal debt in the U.S. currently stands at some $19 trillion, which figure does not include the debt accrued by the 50 individual states, many of which are in bad shape financially. The same can be said of many countries in Europe and Asia, where the total public debt exceeds the gross domestic product.

    Long story short: any money spent on a moondoggle (= moon + boondoggle) would have to be borrowed from somewhere. It's not just lying around, waiting for someone to come along and pick it up.
     
  8. May 21, 2016 #7
    I am not sure how you got to 500 launches.

    Wouldn't you be able to send fully automated missions to the moon which drop 45 tonnes of nuclear power plant parts onto the surface with "parachutes"(actually some kind of jets to slow the fall) on a certain area? The manned mission would follow up later when all materials are available.

    You went from 45 tonnes to 1 tonne and i am not sure how you got there, when the first goal would be to just get the build materials only onto the moon.

    edit: Also the Saturn V is about 50 years old technology. Surely we can do a little better those days if we were to put some effort into creating a single use max payload rocket, or so i hope.
     
    Last edited: May 21, 2016
  9. May 21, 2016 #8

    SteamKing

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    There is no atmosphere on the moon. "Parachutes" won't work, neither will "jets". Whatever is in lunar orbit must use a rocket to come out of orbit to land on the lunar surface.
    Single use max. payload rockets are the most expensive way to take stuff into orbit, which is why Space-X is trying to develop their reusable rocket and why NASA invested so heavily in the Space Shuttle. The Falcon Heavy launch booster developed by SpaceX will be able to carry only about 50 tonnes to LEO.

    https://en.wikipedia.org/wiki/Falcon_Heavy

    Although Apollo technology is old, it has rarely been surpassed since it was flown. The 5 F-1 engines which flew the first stage were the most powerful liquid fuel rockets ever developed.

    https://en.wikipedia.org/wiki/Rocketdyne_F-1

    For about every 3 tonnes payload which reaches earth orbit, 1 tonne can go to the moon. The Saturn V lifted 120 tonnes into earth orbit, sent 45 tonnes to the moon, and got 1 tonne back to earth, which was little more than the 3 astronauts and a few rock samples, so most of that 45 tonnes which went to the moon consisted of the Apollo command/service module and the lunar lander which went to the moon and back to take the astronauts to the Apollo capsule for their return to earth.

    The point is, only a small fraction of what reaches earth orbit can be sent on to the moon and actually reach the surface there. Sure, one way trips to the moon are fine, but after a while, even the moon would get cluttered with space junk which would have to be cleared out of the way so that new payloads from earth could reach the lunar base.
     
  10. May 21, 2016 #9
    I know that parachutes that do not work on the moon :D which is why i typed it in quotes. Jets however when supplied with both oxygen and fuel would work but that is irrelevant to the point. Let's say rockets to break the fall then.

    If that's the cheapest way, then so be it. Let's do this then.

    Yes, true. But the question is, can we develop more powerful rockets with today's technology or not?

    Terrific. That's 40-45 tonnes still that can go to the moon within 1 mission of which its sole purpose is to drop the nuclear plant parts on the moon for later assembly. We are at 10-20 missions still rather than 500.

    Let's assume the worst case scenario. We just drop the 45 tonnes of material on the moon and let the rocket go. That would be 20 billions still to get all parts on the moon. Not 350 billions


    All of which is not needed for the missions destined to get the nuclear power plant parts onto the moon.

    That's not really an argument there. We are talking about getting the first moon base up which is to become self sustained. 20 crashed rockets on the moon won't cause any major "pollution". In fact, you might be able to melt the left over materials and use them, once your moon base facilities for melting metal are up and running.
     
  11. May 21, 2016 #10

    ShayanJ

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    I suggest OP to play Kerbal Space Program. Its realistic enough to teach you how hard and costly is to send something to moon.
     
  12. May 21, 2016 #11
    Give us your numbers then.

    As i see it, even with old technology like the Saturn_V, we are looking at about 1 billion to get 40-45 tonnes of material onto the moon surface on an unmanned mission.
    1 time use rockets which would crash on the moon and their materials be used later as raw materials for the moon base facilities.

    Let's say the whole mission to get the nuclear power plant parts + other tools/machines/materials + engineers/physicists etc required to build a fully sustainable moon base which would expand by using materials found on the moon would cost even $100 billions.

    Once you have that up and running however, every other space mission would become much much cheaper. You would start building spaceships on the moon, that is, if violating multiple patent rights on the moon would be an OK thing to do.
     
  13. May 21, 2016 #12

    ShayanJ

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    Given that you expect that much from NASA, I think its pretty reasonable for me to expect that you invest some money and time to play KSP. I'm not going to explain anything because the explanations given by people who are way above me in this haven't convinced you yet. Just go and play it. Trust me, you'll come to understand.
     
  14. May 21, 2016 #13
    Why nuclear and not solar? And who or what assembles it?

    Where does the infrastructure for mining and processing comes from? And what is the oxygen intended for?

    Where does the infrastructure for the construction comes from?

    Lack of interest.
     
  15. May 21, 2016 #14

    russ_watters

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    You are vastly underestimating the cost and complexity of this. People have pushed you in the right direction, but even the responses you've gotten haven't gone far enough.

    Currently, it costs about $10,000/lb to get an object into low earth orbit. I would not assume Spacex will achieve $1000/lb: people have been trying to achieve that for 40 years (even without inflation!). The Apollo program landed 1/10th of what made it to low earth orbit on the moon and only about half of that could be considered "cargo" (the ascent stage). So that's $200,000/lb to get something onto the moon. A 500 ton nuclear reactor would therefore cost about $200 billion to get to the moon. (assuming one that large could be invented that could function without a source of cooling)

    The next problem should be more obvious:
    Nuclear reactors don't do either of those things. All they do is make power. So not only would you need to invent the devices required to do those things(without humans to run and maintain them!), you'd also have to lift them onto the moon too!
     
  16. May 21, 2016 #15

    Janus

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    Pwer is not the issue, efficiency is. As in how much fuel/reaction mass does it take to deliver a payload. This is a function of the the exhaust velocity of the rocket. You only squeeze so much Ve out of chemical rockets, and chemical rockets are the only thing we have that can generate the types of thrust you need to lift a payload into orbit. (Ion thrusters, for example, are many times more efficient than chemical rockets but can't even produce enough thrust to support their own weight under Earth gravity). You can't just wish the technology you need into existence.
    You can't just drop that 45 tonnes onto the moon unless you want to scatter it across it surface. It will have to be lowered on rockets. Those rockets need fuel and the mass of that fuel will have to come from that 45 tonnes. With present rocket technology, this works to a theoretical minimum of half the 45 tonnes ( assuming you are lowering from low lunar orbit), in actual practice, it will be more. In addition, a good deal of mass will be taken up by engines, fuel tanks, superstructure, etc. You are going to end up with a lot less than 45 tonnes of usable payload on the surface.
    And a great deal of that payload will be used up for the Men, all the supplies and consumables they will need and all the equipment needed needt o assemble the reactor parts.
    The 45 tonnes includes the mass of the rocket needed to get it there. When you left LEO you start with a rocket large enough to hold all the fuel you will need. when you get there you will used up a good deal of the fuel, but the extra mass needed so that the ship would be able to hold all that fuel will still be a part of the ship. So at this point you have two choices: You can land the entire ship, In which case a percentage of the mass landed on the Moon will be dead weight ( stuff you needed to get to the Moon, but not stuff you need to get down to the surface our need on the surface), which lowers the percentage of useful payload you get down to the surface. The other option is to discard that part of the ship that you needed to get to the moon's vicinity but don't need any longer, and just keep what you will need to get your payload down. But that means leaving behind some of the 45 tonnes. The ratio of payload to lander goes up, but the total mass of the lander goes down. In either case, only a fraction of the 45 tonnes makes it to the surface as usable payload.

    The point is that you are severely underestimating the logistical problems of your proposal.
     
  17. May 21, 2016 #16

    Vanadium 50

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    Didn't we have this discussion in another thread? It had the same problem as this one - someone who wanted a lunar base so badly that they were unable to listen to the arguments against it
     
  18. May 21, 2016 #17

    anorlunda

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    I do not believe that technology is the most important ingredient. The willingness to accept and to manage risk is something that they had in abundance in the Saturn V/Apollo projects. I think mostly of the risk of choosing the smartest people and supporting them with resources (even including project management) and lack of meddling. Since the 1960s, risk adversity has taken over. Even NASA's brilliant successes in recent unmanned space missions can not match the achievement of Apollo 11 landing on the moon.

    Regardless of technology, I doubt if 21st century mankind is capable of even matching Apollo 11's magnitude of achievement. I expect that many PF members would disagree, so let's hear it.
     
  19. May 21, 2016 #18
    The problem with the counter-arguments is that they seem to keep ignoring what i said. I clearly said that the missions to drop the necessary build materials required for a self sustainable moon base, capable of expanding by itself by using raw materials from the environment and turning those into new facilities required, would be UNMANNED mission.

    Yet, several times those replying keep adding men to those first 10-20 missions with 1 time use rockets.

    I was hugely conservative in my calculations, giving the saturn_V a cost of 1 billions when the cost will be far less. I even estimated the total cost at 100 billions, when 20 missions would be only 20 billions, leaving 80 billions for the manned mission and everything else.

    Lets assume that one of the repliers who ignored that the first missions would be unmanned was right and you really needed half the weight of the 45 tonnes of the payload in fuel, that would be around 20-25 tonnes still. Then it's 40 billions for the unmanned missions and we are at 120 billions total.
    I highly doubt the 20-25 tonnes of fuel required to land on the moon, on a mission where the 1 time use rocket might also be crashed on the moon. But even IF, you DO realize that this is no counter argument?
    Or someone pointing me to play a game to see how wrong i am, is no counter argument either?
     
  20. May 21, 2016 #19
    Less weight per KW produced. Works 24/7 independent on if the sun is shining or not. You can hide it underground, safe from anything hitting the surface on the dark side of the moon. Later one could add solar arrays with panels built on the moon i suppose.

    I will repeat myself. Everything tools/machines/materials which are ABSOLUTELY necessary to get you started, hence make the moon base self-sustainable and expandable will be provided. You will need some of the best engineers to achieve it and also there will have to be put a lot of pre-thought into the mission. A manual would have to be written which would detail the steps on how to get from raw materials gathered on the moon to full blown factories, robots required etc.
    Not an easy task for sure, but impossible? I don't think so.

    See above. Oxygen would be required for breathing i suppose, among other things, once the first settlers arrive.

    Ok, now i really believe there is a hidden moon base on the dark side of the moon already, and you are part of the conspiracy team trying to hide it from us. "Lack of interest"? Really?
     
  21. May 21, 2016 #20

    1oldman2

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    look at KSP as a simulation not a game, it will prove the respondents point without saying another word.
     
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