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nexium
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Some apparently brilliant people think we can't build the space <br />elevator as Dr. Edwards envisions, so let's analyze some <br />alternatives. Space rated tether may fall short of projections <br />for CNT = carbon nano tube. Segments 3700 kilometers = <br />2200 miles long, 20 micrometers thick, 100,000 micrometers <br />wide = two million square micrometers = 2 square millimeters <br />= 0.02 square centimeters = 0.02 grams per cm length = two <br />grams per meter of tether = 7,400,000 grams of CNT = <br />7.4 metric tones of CNT if the average density is one <br />(same as water).<br /><br /> This permits starting construction as soon <br />as 1% of the required CNT = carbon nano tube is available, <br />even if the CNT is slightly substandard. This can be launched <br />from the space shuttle or several other existing launch systems. <br /><br />Corealis effect will make it more horizontal than vertical, but <br />an ion engine pulling one end to an altitude of 4000 kilometers <br />will make it approximately vertical in a few weeks. Gravity and <br />centripetal force help, but they are slow. A half ton climber <br />can start moving on the tether as soon as the first kilometer <br />has been unwound off the reel. The climber can get its power <br />from surface of Earth lasers just as Dr. Edwards plans, except <br />the solar panel is a moving target. If problems occur at 4000 <br />kilometers, we may have to rethink laser propulsion.<br /><br /> Control of the climber should be temporarily from the<br /> space shuttle as it may be some help in unwinding<br /> the tether. The climber can start adding a thread<br /> before the tether reaches vertical. At 37 kilometers<br /> per hour, average, it will take 100 hours to add one<br /> re-enforcing thread. Hopefully improved models can<br /> lay thread faster.<br /><br /> After the thread is in place the reel will be <br />released making the climber lighter and faster. Fast start <br />and direction reversals will be tested making transients of