Moon to Earth tether/elevator

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nexium

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~If 58,000 km from moon to L1 is about correct, a lunar elevator may be practical, when and if space rated CNT = carbon nanotube tether is available in lengths to 380,000 km. Much shorter is possible, but about 380,000 km will be best for Earth to moon and moon to Earth transport. 380,000 km allows most of the trip to be made on the tether, except the 100 miles to Earth at the moon's closest approach. The Earth end will be easier than reaching Earth orbit as it circles the Earth at about 1100 miles per hour, slower briefly due to transients that travel on the tether. Cargos for destinations other than Earth can be released from the tether at the point best for a sling shot = gravity assist maneuver around Earth. If optimistic projections for the CNT tether become reality, a reel of CNT ribbon one micrometer by one millimeter = one billionth square meter cross sectional area, delivered to approximately L1 may surfice to start the project. 380,000 km will have a mass of 0.38 metric tons (assuming average tether density is one= same as water) plus the reel and a hundred robotic climbers that will add strengthening strands, make repairs every few minutes, and do other chores, delivered to approximately L1. Strain will be greatest on the portion between L1 and Earth, so the quality of the CNT, thickness and/or the width will likely need to be increased for this portion, bringing the launch mass to a few hundred tones, which is mostly climbers. The moon end will the need to be attached to a winch that is well anchored as the tether will sometimes pull with about the force of the maximum Earthbound pay load, when no pay load is attached. The winch can fine tune the tether or pull up to the safe strength of the tether in an emergency. We will want to use the winch sparingly as it's energy use can be high. The climbers can keep strengthening the tether to increase it's payload and margin of safety by adding one thread at a time. The tether may be damaged by micro meteorites
 
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grooble

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I don't understand what is meant by a moon tether, is it like an elevator from the surface of the moon to really far out with a ship dock?
 
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rogers_buck

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I had a thread in Space Business and Technology about an Earth Moon Tether quite a while ago (before the crash). There were some good posts in that thread.
 
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rogers_buck

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Think of a tether with one end bolted to the moon, and the other end dangling above the earth. The forces on the tether would be the integral of the weight of the tether from its closest approach to the earth to center of mass earth-moon. And correspondingly the reverse on the center of mass earth-moon moon leg. I called the climbers "spiders" and used lunar materials to build the tether out from the moon. <br /><br />Payloads, presumably mined ores, would climb the tether to earth vicinity and drop off the end. The payloads would then do a "care free" reentry and parachute to a soft landing. When climbin from the moon the tether would be kept straight by the earths gravity. When climbin from the earth the moons gravity and the fact the tehter is anchored on the moon would keep the tether tight.<br /><br />Tether could be winched in and out from the moon end to compensate for the apogee and perigee of the lunar orbit.<br /><br />Perhaps powerfull lasers encircling the tether on the moon end might deflect any wayward micrometeorites bellow a certain size. These could also be used to thermally stress the tether to keep it plum. They could also provide a source of power for an elevator.<br /><br /><br /><br />
 
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rogers_buck

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Humm. I would like to get the restraunt and bathroom consession along the trail. There could be money yet.<br /><br />Funny, I just remembered what that picture reminded me of. In the old sailing ship days, the rats climbing the ropes to enter the ship. Imagine a big flying sauser at the end with a big round disk on the cable to keep the chimps out.<br /><br />
 
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scottb50

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It's a cook book!!! <div class="Discussion_UserSignature"> </div>
 
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