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#12
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Transporting liquids and gases across the moon
"Alex Terrell" wrote in message
om... An excellent story it is. I also pointed out a few months ago that you could actually use this system to transfer energy. Thanks. Yes, which would be nice given that solar energy might be more constantly available at the poles than at other latitudes. However, I'm a little worried about the accuracy requirement. If a cargo hits the side of an L1 catcher, it explodes at about 20m/s, doing little damage. But these ones will come in at about a km/s. I wouldn't like to underwrite the receiving infrastructure. Granted, pointing would be VERY important. O'Neill talked about use of electrostatic plates downrange of his lunar mass-driver for fine-tuning of trajectory. Some of these spaced at wide intervals along the path would probably be a good idea. -- Regards, Mike Combs ---------------------------------------------------------------------- We should ask, critically and with appeal to the numbers, whether the best site for a growing advancing industrial society is Earth, the Moon, Mars, some other planet, or somewhere else entirely. Surprisingly, the answer will be inescapable - the best site is "somewhere else entirely." Gerard O'Neill - "The High Frontier" |
#13
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Transporting liquids and gases across the moon
"Mike Combs" wrote in message ...
"Alex Terrell" wrote in message om... There are reasons why it's advantageous to have a main lunar base at low latitude, and a water mining base at the poles. But how could cargo be transported bewteen the two. I wrote a short SF story where I had a mass-driver and an "anti-mass-driver" tossing filled and empty buckets of ice back and forth between a polar mine and an equatorial station. http://members.aol.com/howiecombs/tnbttbt.htm The advantage of such a system would be the lack of need for infrastructure between the two points. A few years later, someone at the Space Studies Institute was discussing just such an "anti-mass-driver". Yep, an elegant system. But it might be cheaper, if ice were the only thing being transported, to fling ice cubes using a ground-based rotating tube or sling. A passive catcher at the other end would accumulate the icecubes. No need to make or recycle buckets, no need to maintain two mass-drivers. A 30 meter radius sling spinning at 1000 rpm would do it. Maybe use a laser slightly downrange to zap the icecubes and tweak their trajectories. My favorite general-purpose lunar transport system, though, is still the rotavator, a spinning polar-orbital tether cartwheeling around the Moon, touching down near equator and poles. The acceleration could be gentle enough for passengers as well as cargo and it could also be used to ship people/cargo to and from Earth. We'd need small rocket vehicles to rendezvous with the bottom end of the tether. |
#14
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Transporting liquids and gases across the moon
Marc 182 wrote in message et...
In article , says... (Alex Terrell) wrote in message . com... Are there easier ways of transporting goods across the moons surface? How about a sort of four legged kangaroo transport truck, that jump up and down on the moon surface? A can imagine now, a truck with four pogo sticks. Perharps also with a little bit assistances with retro rockets. Jumping up and down has been a proved method on traveling on the moon. LOL! Oh heck, this might actually be practical. First time I've heard of this idea. Doesn't use reaction mass, can travel rough terrain. I wouldn't want to ride in one tho. Marc Is there any more reason why it should be more practical on the moon than on Earth? (Apart from the lack of rabbit holes on the moon) |
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Transporting liquids and gases across the moon
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#16
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Transporting liquids and gases across the moon
How about a sort of four legged kangaroo transport truck, that jump up
and down on the moon surface? A can imagine now, a truck with four pogo sticks. Perharps also with a little bit assistances with retro rockets. Jumping up and down has been a proved method on traveling on the moon. LOL! Oh heck, this might actually be practical. First time I've heard of this idea. Doesn't use reaction mass, can travel rough terrain. I wouldn't want to ride in one tho. The programming is extremely challenging. Otherwise walking and hopping have some nice improvements over rolling. Imagine going down the highway and your car has the option to hop over someone instead of ramming into them. Imagine if a pothole was nothing, and it took a 2-3 foot ditch before you got even close to worrying about it. But again, the programming is tough. Insects are much better at walking and hopping than computers, these days. -Lex |
#17
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Transporting liquids and gases across the moon
There are reasons why it's advantageous to have a main lunar base at low
latitude, and a water mining base at the poles. Those reasons, whatever they might be, are probably not enough to ignore the advisability of placing the base near the water supply, just as we've been doing here on earth for twenty-seven million years, for obvious reasons. Another advantage of placing the base at the poles is that there would be more hours of sunlight available to provide for solar power. It would also be more cheerful as well as providing more visibility for working than enduring two-week-long pitch-black nights. ^ //^\\ ~~~ near space elevator ~~~~ ~~~members.aol.com/beanstalkr/~~~ |
#18
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Transporting liquids and gases across the moon
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#19
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Transporting liquids and gases across the moon
"Mike Combs" wrote in message ...
"Alex Terrell" wrote in message om... An excellent story it is. I also pointed out a few months ago that you could actually use this system to transfer energy. Thanks. Yes, which would be nice given that solar energy might be more constantly available at the poles than at other latitudes. However, I'm a little worried about the accuracy requirement. If a cargo hits the side of an L1 catcher, it explodes at about 20m/s, doing little damage. But these ones will come in at about a km/s. I wouldn't like to underwrite the receiving infrastructure. Granted, pointing would be VERY important. O'Neill talked about use of electrostatic plates downrange of his lunar mass-driver for fine-tuning of trajectory. Some of these spaced at wide intervals along the path would probably be a good idea. A few problems... unless your payload is moving at orbital velocity (1679 m/sec), it must be lofted at some angle above the horizontal and so will not be hugging the surface within the reach of electrostatic plates for very long. Maybe lasers would be a better way to tweak the trajectories. An off-target one kilogram payload would hit with the same energy as one ton moving at 100 miles/hour. And given that the trip takes about 27 minutes, you'd have a lot of payloads doing a lot of damage while you 'fine-tuned' the trajectories. |
#20
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Transporting liquids and gases across the moon
Lex Spoon wrote:
How about a sort of four legged kangaroo transport truck, that jump up and down on the moon surface? A can imagine now, a truck with four pogo sticks. Perharps also with a little bit assistances with retro rockets. Jumping up and down has been a proved method on traveling on the moon. LOL! snip The programming is extremely challenging. Otherwise walking and hopping have some nice improvements over rolling. Imagine going down the highway and your car has the option to hop over someone instead of ramming into them. Imagine if a pothole was nothing, and it took a 2-3 foot ditch before you got even close to worrying about it. It's not only that, but it's also got problems energetically. While there is no inherent reason you can't regeneratively recover the energy from moving the legs, it's many orders of magnitude more complex than a wheel. A wheel only needs a simple bearing, and uses rotational symmetry to generate the force to move the contact surface backwards and forwards. A leg needs multiple actuators all able to cycle at high rates, and the ability to swing the leg rapidly and accurately and exert high forces. If the control system goes out on a wheel, then you carry on going in the same direction. If it goes out on a leg, you fall over pretty much immediately. |
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