Space elevators: Sci-Fi dream or future reality?

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Space elevators have existed as a concept for more than a century, but without sufficient material technologies they have been relegated to the world of science fiction.

However, this could be set to change, as the idea is seeing renewed interest from commercial companies.

Simply put, a space elevator is system that runs from a point on the Earth’s equator right up past geostationary orbit to a counterweight located in space.

These two points are connected by a 100,000km long tether – a very thin ribbon-like material with enough strength to maintain the connection while supporting 20t of cargo.

Attached to the tether is some form of pulley system that would allow cargo – and humans – to move easily into space, without the need for rockets to escape the clutches of Earth’s gravity.

Such a system would be revolutionary, turning space travel into a relatively low-cost endeavour and greatly increasing the number of people who could leave Earth. Estimates by the International Academy of Astronautics (IAA) even suggest that the cost- per- kilogram of launching items into space could drop from the current rate of $20,000 to the bargain price of $500.

“It could take you from ground to orbit with a net of basically zero energy. It drives down the space-access costs, operationally, to being incredibly low,” explained Google X rapid evaluation team leader Richard DeVaul in an interview with Fast Company.

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A Matter of materials

The biggest issue that is preventing the development of space elevators is the lack of a suitable material to function as a tether.

Earlier this year it emerged that Google X, the technology giant’s secretive research lab for extreme future technologies, had undertaken serious research to determine if development of space elevators was feasible.

Their conclusion was that the tether needed to be at least 100 times stronger than the best steel ever developed, and only one material fitted the bill: carbon nanotubes.

Unfortunately, material science is still working on making carbon nanotubes long enough; at present the most that has been achieved is 1m, a far cry from the 100,000,000m needed.

However, materials science is seeing something of a revolution at present, which is accelerating the development of a whole host of nanoscale materials.

Carbon nanotubes in particular have already been recognised as a key material for a slew of applications across electronics, medicine, energy generation and the military, so there is likely to be strong long-term support for research.

It is quite possible, perhaps even likely, that the generation of suitably long carbon nanotubes is just a matter of time.

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Finding a timescale

How long it will be before space elevators are possible to build is a matter of considerable debate.

The International Academy of Astronautics IAA recently released a report outlining the value and challenges of space elevators, in which the organisation argued that the technology could be possible by 2035. For many, however, such an ambitious estimate is way off the mark.

Peter Debney, engineer for global construction firm Arup, believes the technology is on its way, but will take far longer to be realised.

“I believe that they could be built cost-effectively within a century, and pay for themselves within just a few years,” he said in a post on the company’s website.

“While we have not quite got all the technology in place, and there are still engineering challenges to be overcome, the space elevator has nearly arrived.”


First 3D printer in space to mark start of extraterrestrial manufacturing

For the first time in human history it will be possible to manufacture objects outside of Earth, with the initial microgravity-optimised 3D printer set to launch later this month.

The printer is one of many technologies that NASA is investing in to further long-term space flight, as it will provide the ability to quickly manufacture replacement parts without needing to wait for deliveries from Earth.

NASA astronaut Timothy J Creamer, who spent more than six months aboard the International Space Station (ISS) in 2010, explained the benefits of 3D printing in space.

“I remember when the tip broke off a tool during a mission,” he said. “I had to wait for the next shuttle to come up to bring me a new one.

“Now, rather than wait for a resupply ship to bring me a new tool, in the future, I could just print it.”

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The first printer, which received flight certification in April and has since been tested on a number of microgravity flights, will be shipped to the ISS as part of the SpaceX-4 resupply mission in late September.

Developed under a NASA contract by commercial company Made In Space, the printer will be tested aboard the ISS and, if successful, will be used as the basis for a commercial-scale 3D printer known as the Additive Manufacturing Facility, or AMF.

This will serve as a kind of extraterrestrial maker space by not only enabling the quick printing of replacement parts, but also as a research tool that can be used by Earth-based academics to 3D print in space.

Existing communication systems between Earth and the ISS will even enable parts to be designed on the planet before immediately being printed in space.

“This means that we could go from having a part designed on the ground to printed in orbit within an hour to two from start to finish,” explained Niki Werkheiser, 3D print project manager for NASA.

“The on-demand capability can revolutionise the constrained supply chain model we are limited to today and will be critical for exploration missions.”

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In the long run, it is hoped that the 3D printer will become a valuable component for space travel and exploration, ultimately furthering our ability to travel between planets.

“NASA is great at planning for component failures and contingencies; however, there’s always the potential for unknown scenarios that you couldn’t possibly think of ahead of time,” said Ken Cooper, the principal investigator for 3D printing at NASA’s Marshall Space Flight Center.

“That’s where a 3D printer in space can pay off. While the first experiment is designed to test the 3D printing process in microgravity, it is the first step in sustaining longer missions beyond low-Earth orbit.”


Featured image and inline image one courtesy of Made In Space. Inline image two courtesy of NASA/Emmett Given.