One idea that seems to have an endless supply of lives is the space elevator. The concept of tethering supermaterial to a station in space was first proposed about a century ago. A system of climbers would transport people and things to and from space. Engineering challenges and costs associated with such a structure have always been enormous. New research causes engineers and space agencies to reexamine the concept.
Since no known material is strong enough to handle the stresses involved, the tether is the greatest challenge. This issue may have been solved. According to scientists with the International Space Elevator Consortium, a cost-effective manufacturing process could produce Graphene Ribbons that are strong enough to fashion a tether. The paper they will present at the International Astronomical Congress in Paris will detail their findings.
The research was led by Adrian Nixon, a Graphene and 2D materials scientist, a Royal Society of Chemistry member, and a board member of StellarModal and the ISEC. He was joined by Dennis Wright, the Vice President of the ISECIBM, and John Knapman, who used to work for IBM.
The University of Manchester has a Graphene Engineering innovation centre. Graphene and other 2D materials are developed at this facility.
The Space Elevator is a revolutionary idea for space exploration. Considered to be the top contender for the title of the "Father of Rocketry", Tsiolokovsky is responsible for developing the " Rocket Equation" and the design from which most modern rockets arederived. He proposed how humans could build rotating Pinwheel Stations in space.
He went to Paris in 1895 and saw the Eiffel Tower for the first time. The structure that was conceived from this encounter was an altitude of over 24,000 km. Thecompression structure was called for in the version of the idea by Tsiolkovsky. Since no known material was strong enough to support the weight of the standing structure, the idea was not realistic.
The idea was reexamined by Soviet and American scientists as a suspension structure. The "Sky-Hook" proposed by a group of American engineers in 1966 is one of the examples. These and other versions started with an anchor attached to a fixed point on land or a platform at sea. A captured asteroid, a space station beyond GSO, or a combination of the three would be considered a "counterweight" in space.
A series of climbers would deliver crews and equipment to space, which could be powered by solar panels, nuclear reactor, wireless, or direct energy transfer. The concept has not changed since the Space Age.
The benefits of having a space elevator are easy to comprehend. People can be sent to space for a fraction of the cost of launching them via rockets. It would allow us to build space stations in space, eliminating the need to build them on Earth and use heavy-lift rockets to send them to space. The process has always been expensive.
Between 1970 and 2000 the launch costs were roughly the same. The price has been reduced due to the development of rockets like the Falcon 9 and Falcon Heavy. The cost of sending a mission to space with a Space Elevator could be as little as $113 per pound.
In an email to Universe Today, Nixon explained how a Space Elevator is a "green technology" that can deliver large amounts of cargo without the environmental impact of a rocket launch. Up to 300 tons of carbon dioxide can be released from a single rocket launch. The greatest driver of climate change could be the growing demand for satellite launches and internet.
The railcars do not emit harmful greenhouse gas emissions and can be powered by a combination of space-based solar and nuclear reactor. A Space Elevator would be more efficient and less expensive than many rocket launches. Nixon said that.
“Rockets are very good at delivering small amounts of high-value payloads into space, fast. The space economy is developing rapidly with plans for missions such as a Mars colony, a Lunar village, and space solar power. The planned missions require large amounts of mass lifting from the surface of the Earth to space. However, the key limitation of rockets is their inability to scale to deliver large amounts of mass to space, sustainably. The rocket equation means even a SpaceX StarShip (the most efficient rocket system) can only deliver 2% of the mass on the launchpad to low earth orbit.”
One of the most well-publicized aspects of "Space Age 2.0" is the promises made by entrepreneurs like Musk. There is a promise to build a road to space, increase access through commercialization, and establish the first human outpost on Mars. The enduring issues of cost, inefficiency, and environmental impact of rocket launches mean that these promises will not be fulfilled. He said that the space elevator has the ability to lift massive cargo and deliver it daily, cheaply, safely, routinely, and in an eco-friendly way.
ISEC President and Director Dr. Swan said that the development of the Space Elevator permanent space access infrastructure is a must for humanity to save the atmosphere. Rockets are our approach to these dreams, but they don't have the power or reach to match the needs of humanity. The rocket equation is so bad that we need to do the space elevator.
Every evaluation of the concept has had a problem. Since no known material had the strength to support the structure's weight, a space elevator has not been feasible in the past few decades. During his address to the 30th International Astronautical Congress, Arthur C. Clark summarized the problem as "The Space Elevator: 'Thought Experiment, or Key to the Universe?'".
“How close are we to achieving this with known materials? Not very. The best steel wire could manage only a miserable 31 mi (50 km) or so of vertical suspension before it snapped under its own weight. The trouble with metals is that, though they are strong, they are also heavy; we want something that is both strong and light. This suggests that we should look at modern synthetic and composite materials. Kevlar… for example, could sustain a vertical length of 124 mi (200 km) before snapping – impressive, but still totally inadequate compared with the 3100 (5000) needed.”
There was a renewed interest in space elevators with the development of carbon nanotubes. At the Advanced Space Infrastructure Workshop in 1999, David Smitherman of the NASA Advanced Concepts Office spoke about the feasibility of a space elevator. His arguments were published in a 2000 report about space elevators.
The NASA Institute for Advanced Concepts supported a feasibility study done by Bradley C.Edwards. He stated in his final report that carbon nanotubes were the best candidate since they were thought to have the necessary strength and density. He followed up with the NIAC Phase II Final Report. His conclusions were based on theory and simulation.
The researchers at Tsinghua University in Beijing achieved a maximum length of 20 inches for CNs, which are grown and not machine produced. When placed under extreme stress, the hexagonal bonds that give carbon nanotubes their high strength are likely to break. Nixon summed it up.
“The study reported in 2003 that the space elevator was based on solid science and could be built with today’s engineering technology – just one part remained to be solved – the tether. The tether material needs to be incredibly strong and lightweight. The only material at the time was carbon nanotubes (CNT). At the time of the NIAC report in 2003 CNTs could not be made longer than a few mm. CNT development has not advanced in the last two decades – and the space community lost interest in the space elevator.”
A carbon-based supermaterial that showed immense potential was isolated for the first time after the NIAC Phase II report.
Graphene is an allotrope of carbon composed of a single layer of atoms. Graphene is a two-dimensional material. The two professors from Manchester University were awarded the 2010 Nobel Prize in physics for their work on the two-dimensional material.
The material has amazing electrical properties. The NAIC II Report states that a sheet of single-crystal Graphene has a tensile strength of 200 times that of steel. Nixon and his colleagues were able to brief NASA on the potential of Graphene. Their presentation was part of the commercial space lecture series.
Representatives from the commercial space sector meet with NASA to discuss opportunities for mutual assistance. The point at which kilometer-scale continuous Graphene fibers can be produced was shown in their presentation. The continuous roll-to-roll technique developed by MIT in 2020 could create large sheets of Graphene at a rate of around 2 meters per minute. The Tennessee-based company General Graphene started operations using the CVD method.
In Korea, Charmgraphene has announced that it can make polycrystalline graphene sheets at speeds of 2 meters (6.56 ft) per minute and lengths of 1 km (0.62 miles). The 2D single-crystal variety with the highest strength is not being produced by these companies. They are moving in the correct direction.
“We are starting to see large area sheet graphene being manufactured. While this method had been devised to produce graphene electrodes that would allow for lightweight, flexible solar devices and display screens, the technique can be adapted to create the material for a tether.”
The benefits of 2D single crystal graphene against other candidate materials were considered by Dr. Nixon and his colleagues. The key was to weigh the strength of the material against the efficiency of the production process. Nixon said that.
“We investigated three candidate materials for the study: Carbon nanotubes (CNT), Graphene, and Hexagonal Boron Nitride (hBN). hBN is another 2D material, nearly as strong as graphene and also a candidate tether material. The process for making 2D materials and CNTs is called the chemical vapor deposition (CVD) method. The CVD process uses methane gas to make graphene, and this is an inexpensive feedstock and the basis for the current industrial manufacture.”
Over the past 30 years, little progress has been made in the manufacturing of CNs, the process is painfully slow, and the tubes are never long enough. The manufacturing process is promising, but it is not at the scale and speeds needed to create a tether. The Single Crystal variety was created using Graphene.
The price for producing single crystal 2D sheets of Graphene could be as little as 1 cent per square meter (1 tenth of a cent per square foot), which would mean a tether could be built for $3.6 billion.
The ISEC is committed to making a Space Elevator a reality in our lifetimes. The overall architecture of the ISEC's plan is more than just an elevator. They shared their vision for a series oflactic harbor installations in their 2020 ISEC position paper. The elevators would be located in the Atlantic, Indian, and Pacific oceans.
The mission architecture involves using rockets and elevators to create a space transportation infrastructure that will facilitate the migration of humans from Earth to other planets. Dr. Swan and colleagues created a company to speed up the development of this architecture. The company is dedicated to starting operations with the first harbor by 2037.
In the 2020 ISEC position paper, Dr. Swan and his colleagues wrote about the benefits of the Space Harbor. It will be possible to send 30,000 metric tons (33,069 US tons) of cargo to GSO over the course of a year. It will be possible to send 170,000 metric tons of cargo to GSO at a fraction of the cost compared to rockets. This will allow for many more things.
For the astute observer of spaceflight and the commercial space sector, some of these benefits are familiar. A Space Elevator would help Musk realize his vision of sending 1 million people to Mars between now and 2050, while Bezos would be able to realize his vision of a trillion humans in the solar system. It wouldn't involve thousands of rockets lifting small payloads to space, costing hundreds of billions or trillions, and causing damage to Earth.
The nations of the world need to invest in the idea in order to get us to that point. This is something Nixon, Wright, and Knapman hope to encourage when they present at this year's International Astronomical Congress in Paris from September 18th to 22nd. Nixon said they hope to accomplish something at the IAC.
“In a word, profile! Since the space community turned away from carbon nanotubes, they have not realized that 2D materials even exist. Those that are aware of graphene and hBN don’t realize the astonishing progress being made in 2D materials manufacturing. We hope to spread the word with a well-researched paper, and we encourage as many people as possible to become interested in the space elevator again. The space elevator is not science fiction, it is closer to engineering fact. Could the space elevator be built in our lifetimes? Yes, of course, it just depends on how much serious effort is directed to this amazing technology.”
Lower costs, more competition, and more cooperation are making space more accessible. Many concepts that were once considered unfeasible are being reexamined. Few other ideas have the same potential as a Space Elevator. Many questions need to be answered first to prevent future challenges. There is no shortage of people looking to tackle them.
China hopes to complete its own space elevator by 2045, which is why it is reminding people. The global space economy is worth $447 billion and shows no signs of slowing, so other nations and commercial partners might want to get in on this project before it's too late. You don't want to be left out when space becomes the most profitable market there is.
Be sure to check out the ISEC website for additional resources if you want to become a member or follow the IAC in Paris this September.
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