Space race seems to be heating up again

Discussion in 'Science & Society' started by countezero, Nov 13, 2007.

  1. Killjoy Propelling The Farce!! Valued Senior Member

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    Mustn't waste the next one on empty wasteland, tho'.

    hmmm...

    This looks promising - and expendable...

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    :mufc:
     
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  3. phlogistician Banned Banned

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    That's what the dinosaurs said too.
     
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  5. draqon Banned Banned

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    h y p o t h e s i s
     
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  7. Nasor Valued Senior Member

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    Since no one has managed to build a working fusion reactor yet, it seems a bit premature to talk about helium 3. And it's not like it's just laying around on the moon waiting for us to pick it up...

    In any case, is it really a 'race' if China is attempting to do something that the US did almost 40 years ago?
     
  8. Avatar smoking revolver Valued Senior Member

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    Engineers working on Europe's space station re-supply truck are aiming to have it ready for flight in February.

    The European Space Agency had an early launch target of January, but the final assembly and fuelling sequence of the ATV is proving quite challenging.

    Some components have had to be replaced on the vehicle, including elements involved in docking with the outpost.

    The ATV has been dubbed Jules Verne for its maiden voyage to the International Space Station (ISS).

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    http://news.bbc.co.uk/2/hi/science/nature/7093347.stm
     
  9. phlogistician Banned Banned

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    Got a better one? With supporting evidence? No? Shut up then.
     
  10. kmguru Staff Member

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    11,757
    The Chinese will catch up that 40 years in less than 10 years. Then they will pass forward because they are the manufacturing country while we are fighting the Iranians.
     
  11. jlocke Registered Senior Member

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    412
    While I agree with most of this, you lost me at murder, child molestation, assault, and rape being the result of an over-active ego....

    And, I don't see why you're only looking at the negative results of our ego, even though these things are all negative, they've still allowed the human race to thrive to a dangerous point (but still better than dying out I suppose).
     
  12. Baron Max Registered Senior Member

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    I don't if it's better than dying out ...perhaps we should ask all the other animals in the world. You know, the ones that are being threatened at every step of human existence? The other animals that can no longer live in their own natural habitat because humans are now occupying it and polluting it?

    I wonder what the other animals would have to say about humans "thriving".

    Baron Max
     
  13. DeepThought Banned Banned

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    jlocke,

    Perhaps the desire to conquer and control? Isn't that what psychologists believe drives rapists and child molesters and the like?
     
  14. jlocke Registered Senior Member

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    412
    Again, I was only looking at it from a human perspective, yes it's been worse for...well pretty much everything else in the world, but for our species it's been top notch.
     
  15. Baron Max Registered Senior Member

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    23,053
    Top notch for our species?? Do have any idea of the numbers of people who die of starvation every single day? Do you know how many people are murdered every day? Do you know how many are killed in accidents every single day? Do you know how many people are killed in wars and conflicts all over the world every day?

    No, ain't nothin' "top notch" about us humans!

    Humans suck, man, and I ain't just jokin', either.

    Baron Max
     
  16. countezero Registered Senior Member

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    This thread has gotten way off track...
     
  17. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    I was only reporting what I read as one of the objectives of the currently moon-orbiting Chinese spacecraft's year-long data-collection mission. In another thread, where much nonsense about mining the moon's "wealth" (gold etc) was posted, I pointed out that He3 was probably (in the future, not now) the only thing with a high enough value to mass ratio to make it economically feasible to return it from the moon to Earth. I also expressed my POV that there is no significant amount of He3 on the surface of the moon due to fact it comes from the sun with considerable kinetic energy and very locally on impact heats the atoms it collides with. Even the noon day sun's surface temperatures on the moon are quite warm and would cause any He3 that happened to be there to difuse to the surface and escape into space. Moon's gravity is too small and these temperatures give velocities to He3 greater than the escape velocity at least those (and all will be in a minute or so) in the high energy "Maxwellian tail" of the thermal distribution. Also helium, all isotopes, is extremely capable of passing thru the small latice defects (smaller than anything one would call a "crack"). This is why it used in "leak detectors" checking out vaccuum systems.

    Summary I was only reporting, certainly not advocating collecting He3 from the moon as do not expect to find much there.
     
    Last edited by a moderator: Nov 19, 2007
  18. Echo3Romeo One man wolfpack Registered Senior Member

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    The irony of reading this post on a science-oriented message board is sharp enough to split atoms.
     
  19. MetaKron Registered Senior Member

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    5,502
    We need the moon because if we don't get the moon, the Chinese will use their heavier and cheaper launch capability to plant enough weapons up there to simply pot every city and military installation in the U.S. any time they want.

    They can do this. Whatever some idiot wants to quibble about, Moon to Earth launches use a lot less fuel and cost a lot less than ICBM launches. Stick the nuclear charges in a spherical heat shield, put the guidance electronics in the missile, simply let the missile dissolve around the nuke and have it detonate when it detects the decrease in deceleration.
     
  20. jlocke Registered Senior Member

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    412
    Why would they want to "pot" cities in the US, one of their most important trade partners?
     
  21. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    Not true, you should have also considered the cost and fuel just to get to the rocket with heat shield and weapon to the moon from the Earth to the moon in the first place. (Not to mention the cement, water, steel, etc. for the launch pad /tower on the moon that launch from moon will require or the food of launch crew etc.) Moon launched attack is many orders of magnitude greater cost than the simple ICBM launch from point C (China) to point A (America), both of which are on Earth. I.e. For less cost than putting one weapon rocket on the moon, you could send more than a hundred ICBMs to your Earth target with less cost than just making the required launch facilities on the moon.

    Also of considerable practical significance for the Chinese is that Point "A" has less than 80 minutes warning if launch is from Earth point "C," not four of five days that launching from the moon gives the USA to disperse it navy, air force and other retaliation equipment and critical recovery supplies.

    You appear to be a prisoner of the old "cease the high ground" military rule and incapable of any rational analysis.*

    This is neither the first time you have posted this “Chinese will attack from the moon” nonsense, nor the first time I have had to show how silly / stupid it is.

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    --------------------
    *I know you do not respond to logical or mathematical proofs but it is so easy to compare the energy costs of both alternatives that I will do it.

    The potential energy in a gravitational field is a simple "inverse r equation" and we can neglect all constants like G as we are only interested in the ratio of energies required.

    Let R and r be Earth and moon radii respectively. Let the total distance from the Earth and moon centers be the sum of S+s where S is the distance to that point of equal moon and Earth gravity from the center of the Earth, and s is the distance to that same "balanced point" (called "B") from the center of the moon.

    For trip to B from surface of the earth (lifting each unit of mass), requires {(1/R)-(1/S)} units of energy.

    For trip from B to surface of the moon (slowing fall to moon for soft landing), requires {(1/r)-(1/s)} unit so energy and this same energy to get back to point B when launching from the moon. Hence both coming and going legs of this part of the trip require 2{(1/r)-(1/s)}

    Now one could just let the weapon fall to Earth but it would be going too fast and burn up in the air like a meteor does, so one could surround it with a thick heat shield but that is much more costly than what NASA did to protect the re-entry capsule. I.e. much cheaper (much less weight to take to moon and back than a very thick heat shield) is to use retro rockets to remove almost all of the kinetic energy the weapon would gain during the fall from point B to the surface of the Earth. Thus, from B to R the energy required (to slow the fall is essentially {(1/R)-(1/S)} again.

    Hence the total energy for each unit of mass taken to the moon and then returned to the Earth is 2{(1/R)-(1/S) + (1/r)-(1/s)} for the moon based attack.

    For the ICBM it has a peak distance from the center of the Earth of less than 3R/2 and again I will assume that during its fall from the peak point of the ICBM trajectory it is slowed back down. This is not in fact needed as the heat shield required for re-entry from such a short fall is only a few centimeters of ceramic tiles or even less as they can burn away (not like on the space shuttle where they are reused if undamaged) but I do not want you to say I falsely favored the ICBM over the moon launch in the analysis.

    Thus energy for the ICBM to get to the peak of its trajectory is less than {(1/R) -(2/3R)} and the same on the way back down to the target R distant from the center of the Earth. So the total FOR EACH UNIT OF MASS DELIVERED TO THE TARGET the required energy is 2{(1/R) -(2/3R)}

    Now note that RrSs/2 is just some other constant, and like G, not important for comparing these two alternatives. Hence I multiply the both of the above total energy expressions by it (to get rid of the recipicals) and find that the moon launch energy required for each unit of mass delivered to the target is proportional to:

    (RrSs/2)2{(1/R)-(1/S) + (1/r)-(1/s)} = rSs - Rrs + RSs - RrS
    Whereas the ICBM energy required is proportional to less than:

    (RrSs/2)2{(1/R) -(2/3R)} = rSs - (2/3)rSs = rSs/3

    Hence the energy ratio of Moon to ICBM launches is greater than:

    (rSs - Rrs + RSs - RrS) / (rSs/3) = 3(1 - R/S + R/r -R/s) = 3 + R{(1/r) - (1/S) - (1/s)}

    Now the known mass ratio M/m and the known separation of the centers of the Earth and moon can be used to eliminate both S and s. Also the R/r ratio is well known so this lower limit on the energy ratio can be evaluated exactly, but I will not bother. Instead I will only note that S >> s >> r so the two negative terms inside the { } above are very small compared to the positive (1/r) term.

    Hence at least 3 + (R/r) times more energy is required to launch from the moon than for the ICBM launch. R = 6380km and r = 1740km hence R/r = 11/3 or the moon launch requires at least (for each unit of mass delivered to the target) 6.666 times more energy than the ICBM attack. (Assuming rail guns instead of chemical rockets could be used.)

    In reality this is only possible if BOTH the trip to the moon from Earth and the return to Earth from the moon of the "unit of mass" are not achieved by chemical rockets but are by "rail guns." In fact they would be chemical rockets as that is the cheaper way with present technology. (Probably essentially impossible for any rail gun to accelerate thru the Earth's atmosphere any mass with velocity high enough to the "coast" all the way up to point B, where the moon's gravity becomes stronger than the Earth's.)

    The mass of the chemical rocket sitting on the Earth launch pad required to softly place 100 units of mass on the surface of the moon is at least 1,000,000 units of mass (I have not recently solved the "rocket equation" even with the highest known specific impulse fuel, but 10,000 is the correct order of magnitude for the launch mass to delivered to moon mass ratio*.) Now that 100 units of mass on the moon would not even build the launch pad and tower required for a moon launch (even if only robots made it, instead of food eating, water drinking men) but I will ignore that and falsely assume that 100 units of mass on the moon could deliver one unit of mass back to Earth without it burning up in the atmosphere. Thus the rail gun advantage of a factor of 6.666 becomes approximately 6.6 million with chemical rockets.

    SUMMARY:
    With chemical rockets, instead of rail guns assumed in the above mathematical analysis, approximately 6 million times more energy or cost is required for your extremely silly suggestion of launching from the moon instead of an ICBM launch!!!!!

    I hope you will stop posting your nonsense, (such as suggesting Hemp as the biofuel crop source) but from prior requests that you stop, I know you will not. READERS MUST SIMPLY REMEMBER THAT NOTHING YOU POST CAN BE TRUSTED.

    ----------------------
    *Search and you can no doubt find what NASA needed as the launch mass to put the tiny LEM on the surface of the moon.
     
    Last edited by a moderator: Nov 21, 2007
  22. MetaKron Registered Senior Member

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    5,502
    Billy, do you have any idea how much you make yourself look like a jackass when you talk like that? Please try to make your level of maturity appear to be somewhat closer to your age, or even my age. Your credibility is pretty well shot with the personal attacks and extraneous information that you brought to this discussion. And with this stuff about prior requests to "stop", I have no idea why you think that I should even consider complying.

    One thing that you forget is that China likes "human wave" tactics. This means that they would tend to think that way about missile launches. I don't know the size of the smallest nuke that they can field, but once it's up there, it's up there. Do we have anything that can even dream of intercepting a missile that is coming straight down at 25,000 mph? How about the fact that a spherical reflector has an extremely small radar profile, let alone if it is stealthed with radar-absorbing materials?

    If you look it up the mass ratio to lunar orbit is about 1.3 percent with the Saturn V. But we're not talking about man-rated rockets. The payload ratio can be increased quite a bit by using a higher acceleration that humans can't take, and the whole mess can be assembled in orbit.

    You can look at the specs for the LEM and find out that it takes about 1 units of mass in fuel to deliver one unit of mass back to Earth. It would be a bit less because there is no need to decelerate. For some of the nukes that are available this could be in the neighborhood of 100 pounds per missile, but I think they will go for higher power. The escape velocity of the moon is about 5,000 mph, and the rocket is working against one sixth of a gravity. In fact, it will have even less work to do fired directly at the Earth because of the Earth's pull.

    It's not going to need a big launch tower. There isn't even any wind up there so the launch rigging will probably consist of a few pieces of aluminum pipe. Whatever they use to fire a missile battery from a truck bed or a tank, they will use that.

    The energy that it takes to get down to the Moon is about 4 percent of the energy that it takes to get off of Earth. This does work out to making about half the lander fuel. Fair enough. Remember that the Chinese are using the cheaper boosters that everyone's using to place communication satellites, to get stuff into LEO, then they are moving it to lunar orbit using the greatest economy, and they might be moving a million or more pounds at a time. A million pounds of missiles is about four launches of those big boosters. So you fudge and make it eight launches. That might be thousands of missiles capable of doing a city each.

    Even worse: The Chinese are clever, ambitious, and willing to take risks. Their technological level is ready to exceed ours if it hasn't already. America's seeming lack of ability to take risks has totally fucked us over, I mean really bent us over and stuck it up the exit chute.

    http://en.wikipedia.org/wiki/Apollo_Lunar_Module

    The Wikipedia says that the ascent module weight about 10,000 pounds and carried 5,187 pounds of fuel. The whole vehicle weighted about 32,000 pounds and for descent it carried 18,000 pounds of fuel. It means that realistically without inventing a thing someone could put down at least 10,000 pounds of missiles in one shot. The entire missile battery could be put on that LEM type platform. Then you figure that you can trade a lot of the mass of the command module and service module for more missiles.
     
  23. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    To MetaKron

    You rebutal post (39) is a lot of words (your opinions) and a few facts about the weight of the LEM being half fuel JUST TO GET BACK TO LOW MOON ORBIT. Nothing about the weight of the vehicle launched from earth which launched it all. That the Chinese must also do to get their attack system to the moon. Also not even an effort to refute the matematical proof I presented in post 38 which show your moon based system is about 6 million times more expensive than a simple ICBM attack, which also has the advantage of giving less than 80 minutes for taking cover or dispersing assets, in stead of 4 or 5 days that are available if the attack comes from the moon.

    I did not attack you personally as you do me. I only proved your ideas are silly and stupid and warned readers that your posts are sometimes (not always) nonsense. I will not discuss this more with you until you show, quantatively (not by your opinion) some flaw in the post 38's mathematical proof that the attack from the moon idea is EXTREME nonsense.
     
    Last edited by a moderator: Nov 21, 2007

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