Space Elevators Affirmative
Plan Thus my partner and I present the following plan: The United States federal government should construct a space elevator Solvency
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PlanThus my partner and I present the following plan: The United States federal government should construct a space elevatorSolvencyThe space elevator has lower costs, environmental, and exploration benefits.Kate Burkett and Nari Kim, 2010, University of Kansas, Celestial Railroad – The Space Elevator, http://www.kateburkett.com/SpaceElevator.pdf Why build a space elevator? Reduced costs Although the space elevator takes longer to reach GEO than a traditional space shuttle, the cost of transporting the cargo to space would decrease significantly. Instead of costing $10,000 per pound, supporters of the space elevator predict that the invention will lower the price tag by 99- percent, to $100 a pound (Chang, 2003). In addition, the advancement of recent research has lowered the estimate for building the elevator to $6 billion. This is in comparison to the estimated total cost of the International Space Station, which has exceeded $100 billion (Chang, 2003). If Dr. Edwards were to receive $5 billion in funding today he estimates that, "In 15 years we could have a dozen cables running full steam putting 50 tons in space every day for even less” than $100 a pound. Each space elevator built will make the next one cheaper, lowering the cost to $2 billion, because the first elevator would be the vehicle lifting the materials into space (Dorneanu, 2007). The green elevator The easier economical access to space would also allow important projects not currently practical to be further considered. Undertaking actions helpful to the environment like sending large numbers of solar powered satellites into space to collect sunlight and beam energy back down to Earth would be seen as less lavish. Others suggest that the elevator could be used to shuttle and dispose of nuclear waste (Steere, 2008). Earth’s orbit and beyond Much like the transcontinental railroad, proponents of the space elevator believe it will usher in a new era of human civilization. Like the American west was opened by the transcontinental railroad, the space elevator has the capability to open up transportation to the stars and revolutionize space travel by creating a permanent connection between Earth and space. Since the problem of defeating Earth’s gravity will be overcome, trips beyond the moon will become actual possibilities. If supported, the space elevator could become the vehicle to explore a new frontier.9
Some of these challenges would be met merely by locating the elevator’s Earth anchor in the eastern equatorial Pacific, west of the Galápagos Islands, where the weather is unusually calm and the threats from hurricanes, torna-does, lightning, jet streams, and wind are greatly reduced. This location is also about 650 km from any current air routes or sea lanes, significantly reducing the chance of an accidental collision and making the site easier to secure against terrorists. An anchor in the Pacific obviously implies a floating platform, but such structures are already commer- cially available, thanks to the offshore oil industry [see illustration, “Elevator Ahoy”]. These platforms would be mobile, which would allow the elevator, with sufficient warning, to avoid orbiting satellites and debris by moving the anchor end of the cable back and forth about 1 km, pulling the ribbon out of the path of an oncoming object. While debris and other objects down to 10 cm in diameter are currently tracked, objects with diam- eters as small as 1 cm are a potential threat to the elevator. As a consequence, the current ele- vator system design includes a high-sensitivity ground-based radar facility to track all objects in low-Earth orbit that are at least 1 cm wide [see illustration, “Watching the Skies”]. A system like this was designed for the International Space Station but never implemented. Eliminating erosion from atomic oxygen at altitudes of 100 to 800 km would be the job of thin metal coatings applied to the cable. Radiation damage would be mitigated by using carbon nanotubes and plastic polymer materials that are inherently radiation resistant. To avoid problems with cable oscillations induced by tidal forces, my ribbon design calls for a natural resonant period--7.2 hours--that does not resonate with the 24-hour periods of the moon and sun. Any oscillations that do occur would be damped by the mobile anchor station. Induced electrical currents would be generated only if the ribbon cut through Earth's, or an interplanetary, magnetic field. Because the ribbon would be stationary relative to Earth's magnetic field, only dynamic changes in the magnetic field could cause currents in the ribbon, and these would be small. The interplanetary magnetic field is also small, except in cases of extreme solar activity, and even then, the currents generated would be on the order of milliwatts and easily dissipated. Currents caused by charged plasma in Earth's ionosphere would also be negligible, because the ribbon's composite material would have high electrical resistance. The last challenge, and the one that sparks the most interest in today's geopolitical climate, is terrorism. Despite the elevator anchor's remoteness and defensibility, an attack that severs the elevator cable--for example, by detonating a bomb planted on an elevator car--is a possibility. So what would happen if the cable were cut? Science-fiction scenarios have portrayed a space-elevator cable failure as a global disaster, but the reality, for my design, would be nothing of the sort. Remember that the ribbon's center of gravity is in geostationary orbit, and the entire cable is under tension as the counterweight swings around Earth. If the ribbon were to be severed near the bottom, all the cable above the cut would float up and start to drift. Calculations show that the ribbon and counterweight would most likely be thrown out of Earth orbit into open space. Of course, the cable below the severed point would fall. But because the linear density of the rib- bon would be just 8 kg/km, literally lighter than a feather, proportionally speaking, it would be unlikely to do much, if any, physical damage. In the worst- case scenario, where the cable is severed near the top, in space, the released counterweight would fly out of Earth orbit and nearly the entire ribbon would begin to fall down and wrap around the planet. As the ribbon fell it would gain velocity, and any rib- bon above the first 1000 km would burn up when it hit the atmosphere, producing long, light ribbons that are meters to kilometers in length. It would be a mess and a financial loss, and probably an impres- sive light show in the upper atmosphere, but nothing like a planetary disaster. Some toxicity issues are being investigated in connection with inhalation of ribbon debris, but initial results indicate that the health risks would be small. Directory: file -> view view -> Western Europe after wwii view -> Author study: paul fleischman view -> Qpa1 7ela study Guide view -> Arctic Oil/Gas Neg view -> November 1970 Approximately 150,000-500,000 deaths Bhola Cyclone Bangladesh view -> Grade Level: 6 Unit of Study: Caribbean glce view -> Citation: Duffield, Katy view -> Table of Contents Lesson # view -> Chinese Wind Energy Disad Download 377.48 Kb. Share with your friends:
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