We look up at the stars almost every night, some wanting to travel out there. However, traveling to space is only for the few, talented, and privileged. Childhood dreams of becoming astronauts are quickly dashed as we get older and realize how unlikely our chances are. Even after all our progress after the space race, traveling into space is incredibly dangerous and costly. So space programs have recently turned to the concept of a space elevator: the idea of tethering an anchor on Earth to a ballast in space with an elevator to travel along the tether. As we look toward the future of space travel in the 21st century, the space elevator is becoming increasingly attractive for its uses, relatively simple design, and cheap costs.
         
          The very first purpose a space elevator would serve is for government orientated tasks. One such task is putting satellites into Geostationary Earth Orbit (GEO). Launching satellites into space via surface based rockets may seem like the easiest and most immediate method. While it is the most immediate, it is not the easiest. To launch a surface rocket carrying a payload, such as a satellite, space agencies need to account for fuel and atmospheric resistance. With a space elevator, space agencies have the capability to transport the satellite carrying rocket to an altitude above Earth where gravity and air resistance are negligible (Quine et al. 15). If you were to send a payload to the ballast of the tether instead, the velocity from the orbit around the Earth could be used to sling-shot the payload to distant destinations like the Moon, Mars, Saturn or Mercury (Smitherman 30). The positive effects of constructing a space elevator will bring are broad and far reaching. As Dr. Edwards states in his space elevator report, the immediate first use of the space elevator is deployment of Earth-orbiting satellites for telecommunications, military, Earth monitoring, etc (Edwards 26). In 2013, the United States launched 79 satellites into orbit (Launches Per Year). With a space elevator alone, it is estimated that it will be capable of launching 110 United States satellites when it is fully operational (Edwards 27).

          The applications and uses of a space elevator would need to be far reaching and lucrative.  More so than government satellites and tasks alone. According to Edwards, a space elevator would do just that, “The immediate market size expected when the space elevator is ready to launch its first commercial payload is around two to three billion dollars per year and expected to grow rapidly as system operations improve” (23). Such an industry would encompass many fields of work, including communications and remote sensing systems that can reach far away locations, and even tourism (Quine et al. 6). These examples represent the applicable future of space elevators.

          Thinking further down the line, a space elevator would provide fast and easy access into space resulting in numerous benefits for the space community and the Earth itself. As Systems Analyzer at NASA David Smitherman points out, this could result in industries known for polluting Earth’s biosphere being moved into space (Smitherman 30). Additionally, moving supplies and large objects into space would no longer require a massive expenditure of fuel on Earth. With a space elevator, the same tonnage of cargo could be carried with only electrically powered systems (Smitherman 30). As Smitherman explains, space elevators have the ability to be extremely ecofriendly, “A space elevator can allow the construction of massive solar-powered systems in orbit and help carry the power down to Earth. This could alleviate the problems of large-scale power production in the biosphere, end strip mining for coal, reduce power plant emissions and greenhouse gas production, lower radiation levels, and perhaps have a positive impact on global warming concerns” (30). Along with that, the research needed to build a space elevator would result in lighter weight materials which would benefit transportation vehicles (Smitherman 30). The space elevator is one of very few inventions that may allow Earth to lower orbit launches cost less than $10/kg. (Smitherman 29) The low cost of sending objects into space via a space elevator would remove the budget and resource limitations of exploring the solar system. Industries like extraterrestrial mining, colonization, and exploration (Smitherman 29). For extraterrestrial mining, it would create a new supply of rare earth metals among other resources, while developing technology that could potentially be used to prevent an asteroid from impacting Earth (Smitherman 30). Perhaps even more importantly, a space elevator’s access to space may be the only way to feasibly build extraterrestrial human colonies (Smitherman 30).

          Next in line for building a space elevator, is where to put anchor on Earth. Because Earth rotates on a tilted axis, it will need to be near or on the equator, otherwise, the tether could collapse due to an irregular rotation around the Earth. Research done by NASA has narrowed down two possible anchor locations: The Indian Ocean at 70 and the Pacific Ocean at 104W (Smitherman 24). As for what the anchor should be, Edwards cites the use of a mobile sea platform (Edwards 16). Such a platform would be needed due to the vast amount of objects, manmade or otherwise, in orbit around Earth. The US Air Force alone detects approximately 8,700 objects 10cm or larger in diameter orbiting Earth (Smitherman 25). As a result, precise and accurate radar would be needed to locate orbiting objects and their trajectories, to determine if the elevator needs to be moved out of the way of impact (Quine et al. 3). Another issue to consider is the effect a space elevator will have on other major space infrastructure developments like a space station, which are not so easily moved (Smitherman 27). Along with orbiting objects impacting the elevator in orbit, there are a few other destruction or damage scenarios to prepare for. If the tether were to bend away from the vertical axis of the anchor by 10s of degrees, the damage is found to be catastrophic (Edwards 15). Given how thin the tether is compared to its length, a lightning strike would break the tether. However, despite extended monitoring of potential anchor sites, the actual danger presented by lightning cannot be ascertained (Quine et al. 3).
 
          Perhaps the most important part of building a space elevator, is assembling it. Building it like a skyscraper is simply infeasible due to the sheer height of it. So then the option becomes to deploy the elevator in pieces from space craft, carrying sections of it into GEO. The issue here is then how to create an efficient system to transport the massive amounts of materials into orbit for construction (Edwards 21). With current space shuttle technology, sending sections of the elevator into space for assembly is determined to require at least 24,000 separate flights (Quine et al. 3). However, using a shuttle with a far more powerful and advanced engine would allow significantly less flights to transport the space elevator into orbit for assembly. One such viable option is the magnetoplasmadynamic thruster (Edwards 21). Sending the sections of the elevator into orbit for assembly is difficult, but not impossible.

          In order to build a space elevator, certain emerging technologies are required. Let’s look at them in greater detail. For the material that will support the space elevator, it will need to be strong on an unprecedented scale. The best material of the 21st century, and possibly later, for the structure of a space elevator is Carbon Nanotubes (CNTs). Edwards put it best, “As we have stated many times, steel is not strong enough, neither is Kevlar, carbon fiber, spider silk or any other material other than carbon nanotubes.” (Edwards 7) At our current understanding of CNTs, their theoretical strength is 300 GPa (Edwards 7). Despite the extreme strength CNTs can have, they are eroded away at one nanometer per month by high density of atomic oxygen. As a result, sections of the tether will need a surface coating to prevent it from losing mass and strength (Quine et al. 3). Even though CNTs have enormous strength today, they are inapplicable to larger scale structures with our current CNT creation method (Espinosa et al. 1). However, it would be theoretically possible to build the structure of a space elevator out of materials available today if the structure is thick enough to compensate for the strain and cargo load (Smitherman 4). For the elevator itself, it may be the most beneficial to use a MagLev mechanism (“Magnetic levitation is the process of levitating an object by exploiting magnetic fields. If the magnetic force of attraction is used, it is known as magnetic suspension. If magnetic repulsion is used, it is known as magnetic levitation.”) (Williams 4). The reason being, is that if we were to create the elevator mechanism using rollers, the contracting and expanding of the ribbon would cause slippage, and create wear and tear which could lead to inconvenient repairs (Edwards 18). Because the anchor would be attached to a moveable sea platform, it may not be possible or convenient to have an onsite power facility. The solution to this problem is to outsource the space elevator’s energy to offsite locations. This energy would then be wirelessly transferred to the elevator. Current comprehension of wireless energy has an efficiency rate of 49% when using an array of satellites (McLinko et al. 7). While this is expected to increase as our technology progresses, it may be more viable to simply attach solar panels to the ballast and tether. Promisingly, all of this technology should be attainable in the next few decades (Smitherman 29).

          For the simple design, many uses, and cheap expenses, the space elevator should be easily attainable at some point in the future of the 21st century. Not only is it very efficient at its intended uses, but it will ultimately bring change to other industries. The impact would extend all-round the globe, connecting humanity like never before as satellites are brought online at an unprecedented rate. Perhaps even most exciting, is that it will unlock our access to what the famous television show Star Trek has so correctly dubbed the final frontier: space.



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Quine, B. M., R. K. Seth, and Z. H. Zhu. "A Free-standing Space Elevator Structure: A Practical Alternative to the Space Tether." (n.d.): 1-27. Web. 30 Oct. 2014.
Smitherman, D. V., Jr., comp. "Space Elevators: An Advanced Earth-Space Infrastructure for the New Millennium." (2000): 1-47. Aug. 2000. Web. 30 Oct. 2014.
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