Space Elevators

[Anonymous]

The threat of terrorism is becoming a major theme in SF and speculative non-fiction these days; it is easy to see why.

No doubt the real threat of terrorism will be addressed in the next two hundred years; unfortunately this could become a kind of arms race, with terrorists constantly improving their methods just as the science of detection and surveillance improves.


I have suggested in the Orion's Arm scenario that the Earth in the twenty-second century will be obsessed with security issues.

Through the use of comprehensive bureaucratic technology the world's population has been stabilised at the high but theoretically sustainable figure of twelve billion; a high tech infrastructure allows most of those twelve billion to live comfortably, but there are still dissenting voices.
Following repeated terrorist outrages in the last two hundred years a relatively efficient system of surveillance and security has been put into operation, with at least a third of the population engaged in security related industries. Thanks to the ubiquitous surveillance tech crime rates have plummeted; for those who are content with mass entertainment, densely populated arcologies and conformity, the Earth is a fine place to live, free of hunger and conflict, crime and antisocial behavior (for the most part);

For others it is stifling, and the waiting list for the space program is endless.

Our world has two apparently different paths to follow in the next
few hundred years, the path of increasing personal freedom and
freedom of trade, and the path of social control and big brother
surveillance. It may be that David Brin is right, and the only way
to reconcile these two forces is by a 'transparent society'.

Such a world assumes that we take responsibility for each of our
actions; and in such a world terrorism would be made more difficult.

But in such an open society perhaps many of the suspicions and
grievances of today's political world could be exorcised.

 

[Mighty_Emperor]

Company Plans To Build Space Elevator

Apr 26, 2005 2:13 pm US/Pacific

BREMERTON, WA (AP) A company in Washington State wants to send an elevator into space.

The LiftPort company says it will open a plant this summer in Millville, New Jersey, to start producing nanotube fibers, which are 60-times stronger than steel.

The company plans to create an eight-inch wide ribbon that would stretch from an ocean platform 62-thousand miles into space.

A robotic elevator would crawl up and down the elevator to carry satellites and eventually people into orbit.

The city of Millville and a county development project provided 100-thousand dollars to build the plant, which will have six employees. The three-year-old company, which has nine employees in Bremerton, Washington, also plans to sell nanotubes fibers to strengthen glass and plastic products.

---------------------
© 2005 The Associated Press.

Source

 

[sunsplash1]

Good luck Millville!

 

[ramonmercado]

Riding A Ribbon To Space A Thousand Feet Closer

Riding A Ribbon To Space A Thousand Feet Closer

LiftPort says it has completed preliminary tests of its high altitude robotic lifters under its waiver to use airspace granted by the Federal Aviation Administration.

The lifters are early prototypes of the technology that the company is developing for use in the LiftPort Space Elevator, its commercial space elevator to ferry cargo back and forth into space.

In tests conducted in Washington state last week, the robotic lifters successfully climbed 1,000 feet up a simulated, working space elevator - a model elevator "ribbon" attached to a moored high altitude balloon. According to the company, these tests represent the first-ever use of this technology on a free-hanging ribbon in the development of the LiftPort space elevator concept.

"These tests mark an historic milestone, in regards to the general space elevator concept as well in the development of the LiftPort Space Elevator, and we appreciate the FAA's willingness to work with us on these tests," said Michael Laine, president of LiftPort Group.

"The ability to test our hardware in a simulated working environment is a critical step in the ultimate development of the LiftPort Space Elevator. Additionally, these tests are dual use - not only will they help us learn more about the things we need to do to ultimately build the LiftPort Space Elevator, but they have great value for real world applications today.

"Our system called HALE (High Altitude Long Endurance) will have uses in a variety of fields. For example, after a natural disaster, we can provide radio, cellular or Internet access using our platform as a relay station. Or it could provide real time surveillance over the damaged region. Once our hardware is tested, we believe it can be deployed to save lives."

The company plans additional tests later this fall. Dates for the tests will be forthcoming.

A revolutionary way to send cargo into space, the LiftPort Space Elevator will consist of a carbon nanotube composite ribbon eventually stretching some 62,000 miles from earth to space.

The LiftPort Space Elevator plans to be anchored to an offshore sea platform near the equator in the Pacific Ocean, and to a small man-made counterweight in space. Mechanical lifters are expected to move up and down the ribbon, carrying such items as people, satellites and solar power systems into space.

Copyright 2005 by Space Daily, Distributed United Press International

http://www.physorg.com/news6855.html

 

[ramonmercado]

Wanted: Inventors to Build Space Elevator

Wanted: Inventors to Build Space Elevator

Patrick Di Justo

Space travel is relatively cheap compared with the cost of leaving Earth. The space shuttle, for instance, burns more than half a million gallons of fuel blasting into orbit, making every pound of payload cost $10,000. Now the nonprofit Spaceward Foundation, with a $400,000 grant from NASA, hopes to fast-track the technology to reach space on the cheap, without rockets.
Later this month, the agency will host the 2005 Beam Power Challenge, a $50,000-prize contest to inspire the automated climbing machines and wireless power necessary to lift people and cargo into space on a 21st-century elevator cable.

First imagined by Russian space pioneer Konstantin Tsiolkovsky in 1895, a space elevator consists of a thin, ultrastrong tether that would stretch from Earth's surface to geosynchronous orbit, a distance of about 22,300 miles. Laser or microwave beams would power elevator cars up the tether.

The goal of the challenge, expected to take place at the NASA Ames Research Center in Mountain View, California, is a bit more modest: to send an automated climber, loaded with cargo, to the top of a 200-foot Kevlar-like tether at a rate of at least one meter per second. A 10-kilowatt xenon spotlight, shining upward from the base of the cable, will power each climber. The fastest climber toting the heaviest payload wins.

Such a setup won't whisk you into orbit, but that's beside the point, says Spaceward Foundation director Ben Shelef. "It will get more minds working," he says. Below, Brad Edwards, author of The Space Elevator: A Revolutionary Earth-to-Space Transportation System, rates the favorites. Team: University of British Columbia
Climber: A 1.7-pound aluminum disk hugs the cable. It's driven by a 60-watt DC motor, controlling one roller. Payload: ~15 kg.
Power System: The xenon beam strikes 320 silicon photovoltaic cells connected like Christmas lights so that failure in one cell won't knock out the whole system.
Stumblink Block: Complicated clutch/gear system improves lift but wastes nearly 70 percent of available energy.
Brad's Take: "The total power is a bit low. It doesn't sound as if it's going to go really fast, but in this first test, if you make it up to the top, that's a success."

Team: MNK Scientific
Climber: A three-foot, Mylar-coated parabolic dish focuses the beam onto a solar engine, which powers the climber. Payload: ~30 kg.
Power System: The beam powers a highly efficient Stirling engine, heated to 1,202°F by the parabolic mirror.
Stumblink Block: Stirling engines need to warm up to 932°F before they work. That could take up to 10 seconds—a serious handicap when overall time is measured.
Brad's Take: "A very interesting design, which could be the most efficient. I hope they test it beforehand—the Mylar might melt under such a strong power source."

Team: DFW Spaceport.com
Climber: A 20-pound sport wheelchair frame, lifted by a 350-watt electric wheelchair motor. Payload: ~45–68 kg.
Power System: Like the Snow Star, this ride relies on photovoltaic cells, only they are made of gallium arsenide, not silicon. It also features a "secret" power source, the S.M.E.G.
Stumbling Block: High heat could melt the off-the-shelf components, which were purchased from local hardware and auto-parts stores. Then there's the mysterious S.M.E.G.
Brad's Take: "It's a good plan. The gallium arsenide cells are much more efficient than silicon. The S.M.E.G. might be an acoustic engine, but that's just a guess."

Space

 

[ramonmercado]

Stronger Than Steel, Harder Than Diamonds

This materiel might help build a Space Elevator.

Stronger Than Steel, Harder Than Diamonds

Buckypaper is made from carbon nanotubes - amazingly strong fibers about 1/50,000th the diameter of a human hair that were first developed in the early 1990s. Buckypaper owes its name to Buckminsterfullerene, or Carbon 60 - a type of carbon molecule whose powerful atomic bonds make it twice as hard as a diamond.
Tallahassee FL (SPX) Oct 21, 2005
Working with a material 10 times lighter than steel - but 250 times stronger - would be a dream come true for any engineer. If this material also had amazing properties that made it highly conductive of heat and electricity, it would start to sound like something out of a science fiction novel.
Yet one Florida State University research group, the Florida Advanced Center for Composite Technologies (FAC2T), is working to develop real-world applications for just such a material.

Ben Wang, a professor of industrial engineering at the Florida A&M University-FSU College of Engineering in Tallahassee, Fla. , serves as director of FAC2T, which works to develop new, high-performance composite materials, as well as technologies for producing them.

Wang is widely acknowledged as a pioneer in the growing field of nano-materials science. His main area of research, involving an extraordinary material known as "buckypaper," has shown promise in a variety of applications, including the development of aerospace structures, the production of more-effective body armor and armored vehicles, and the construction of next-generation computer displays.

The U.S. military has shown a keen interest in the military applications of Wang's research; in fact, the Army Research Lab recently awarded FAC2T a $2.5-million grant, while the Air Force Office of Scientific Research awarded $1.2 million.

"At FAC2T, our objective is to push the envelope to find out just how strong of a composite material we can make using buckypaper," Wang said. "In addition, we're focused on developing processes that will allow it to be mass-produced cheaply."

Buckypaper is made from carbon nanotubes -- amazingly strong fibers about 1/50,000th the diameter of a human hair that were first developed in the early 1990s. Buckypaper owes its name to Buckminsterfullerene, or Carbon 60 -- a type of carbon molecule whose powerful atomic bonds make it twice as hard as a diamond.

Sir Harold Kroto, now a professor and scientist with FSU's department of chemistry and biochemistry, and two other scientists shared the 1996 Nobel Prize in Chemistry for their discovery of Buckminsterfullerene, nicknamed "buckyballs" for the molecules' spherical shape. Their discovery has led to a revolution in the fields of chemistry and materials science -- and directly contributed to the development of buckypaper.

Among the possible uses for buckypaper that are being researched at FAC2T:

If exposed to an electric charge, buckypaper could be used to illuminate computer and television screens. It would be more energy-efficient, lighter, and would allow for a more uniform level of brightness than current cathode ray tube (CRT) and liquid crystal display (LCD) technology.

As one of the most thermally conductive materials known, buckypaper lends itself to the development of heat sinks that would allow computers and other electronic equipment to disperse heat more efficiently than is currently possible. This, in turn, could lead to even greater advances in electronic miniaturization.

Because it has an unusually high current-carrying capacity, a film made from buckypaper could be applied to the exteriors of airplanes. Lightning strikes then would flow around the plane and dissipate without causing damage.

Films also could protect electronic circuits and devices within airplanes from electromagnetic interference, which can damage equipment and alter settings. Similarly, such films could allow military aircraft to shield their electromagnetic "signatures," which can be detected via radar.

FAC2T "is at the very forefront of a technological revolution that will dramatically change the way items all around us are produced," said Kirby Kemper, FSU's vice president for Research.

"The group of faculty, staff, students and post-docs in this center have been visionary in their ability to recognize the tremendous potential of nanotechnology. The potential applications are mind-boggling."

FSU has four U.S. patents pending that are related to its buckypaper research.

In addition to his academic and scientific responsibilities, Wang recently was named FSU's assistant vice president for Research. In this role, he will help to advance research activities at the College of Engineering and throughout the university.

"I look forward to bringing researchers together to pursue rewarding research opportunities," Wang said. "We have very knowledgeable and talented faculty and students, and I will be working with them to help meet their full potential for advancement in their fields."


http://www.spacedaily.com/news/materials-05zx.html

 

[Rubyait]

Space elevators stuck on the first floor

A NASA competition designed to lay the groundwork for futuristic space elevators has ended with no one scooping the two $50,000 top prizes. But officials say the contest is just the first step in developing the technologies needed to use robots to lift objects into space on long, thin super-strong tethers.

Ten teams competed in the challenge, which was held over the weekend at NASA's Ames Research Center in Mountain View, California, US. The event was split into two competitions to test either robot climbing or tether strength.

Seven teams entered the "Beam Power Challenge", where participants built robots that scaled as far as possible up a 61-metre cable. They used photoelectric cells to convert radiation from an industrial searchlight into electricity for the climb.

Those that carried the most weight the highest – while maintaining an average speed of 1 metre per second – would have won a $50,000 grand prize. But no team was able to meet the speed requirement, although a group from the University of Saskatchewan in Canada set the height record at 12 metres.

Light and strong
Sustaining power for the climb appears to have been the main limiting factor. "One of the problems with a power beam is you get so much fall off in light intensity the farther it goes," says NASA spokesman, J D Harrington.

He adds that teams were restricted to using NASA's searchlight as the power source this year, but says they will be able to design their own in 2006. "They can use lasers, microwaves, whatever they like," he says.

Four teams entered the "Tether Challenge", which also carried a $50,000 purse. In that contest, teams had to build tether loops lighter than 2 grams. These had not only to be stronger than their competitors' tethers, but also 50% stronger than a reference tether supplied by NASA, made from commercially available materials.

A tether built by Centaurus Aerospace of Salt Lake City, Utah, managed to carry 544 kilograms before snapping. But that was still not as sturdy as the house tether, which supported 590 kg. The house tether was produced by the Spaceward Foundation, a space advocacy group in Mountain View that administered the contest with NASA.

NASA says it was pleased with the quality of the entries, especially considering the event was only announced in March. "We would have probably been more surprised had someone won – they only had six months to prepare," says Harrington.

Next year, both contests will be repeated but the top prizes will rise to $100,000.

http://www.newscientistspace.com/article.ns?id=dn8203

 

[ramonmercado]

Even on the ground, space elevators may have uses
21:50 26 September 2006
NewScientist.com news service
Kelly Young


The hope is that one day a space elevator, comprised of a robot that will climb a strong tether about 100,000 kilometres (60,000 miles) long, will be able to send humans or other cargo cheaply into space.

Developing the technology necessary to accomplish this goal will take years, but some progress has been made so far. LiftPort Group, based in Bremerton, Washington, US, stretched a cable one mile (1.6 kilometres) into the air in Arizona, US, in January 2006 using a cluster of three balloons (see Space-elevator tether climbs a mile high).

But that test lasted for only six hours. Now, LiftPort has finished a 60-day test with a 100-metre-long tether held aloft by four helium balloons. The test was designed to see what kinds of problems would crop up if such a platform were used to transmit Wi-Fi signals. The lofty platforms would be especially useful for providing Wi-Fi coverage to rural areas, says company president Michael Laine.

Swallows and bats
Overall, he says, the test went well, but there were several unexpected encounters with wildlife. More than a dozen insect egg colonies had been laid on the tether, and in the first few days of the test, curious bats flew around the balloons, apparently attracted by the sound made by the tether's vibrations. Late in the test, swallows were also seen swooping down on the balloons, possibly to sip the morning dew on their surfaces.

"That's the difference between a 6-hour and a 60-day test," Laine told New Scientist.

The company also tested their climbing robot on this tether, even though it was not crucial to finding out whether the balloons would work as a Wi-Fi station. The robot will be necessary in the future for delivering new helium tanks to balloons at higher altitudes.

The team learned that if the tether is pulled hard by wind, it starts to buckle and deform slightly, creating crinkles. The robot climber hit these crinkles and could not proceed because they made the tether too thick for it to handle.

"We broke our robot by doing this," Laine says. "It's the kind of failure we never would have learned had we only been doing 6-hour tests." Future designs will have to incorporate sensors to tell the robot when it is about to encounter varying thicknesses.

Strong but thin
LiftPort is now working with North Carolina State University and Rutgers University, both in the US, to develop a 5-km- (3-mile-) high tether system. Several weeks ago, the company also made its own carbon nanotubes for the first time. Because carbon nanotubes are extremely thin but incredibly strong, they have been studied for use in a lightweight tether that could reach all the way to space.

Other groups are also working towards building a space elevator. On 20 and 21 October, more than 20 teams will compete in the second round of NASA's Beam Power and Tether Centennial Challenges, competitions to spur the development of technology required for a space elevator.

In the Beam Power challenge, teams will try to use light to power a robot that needs to climb 50 metres at a rate of 1 metre per second or faster. The Tether challenge will test the strength of the competitors' tethers. LiftPort will not compete in the contests, as Laine sits on the board of the California-based Spaceward Foundation, which partnered with NASA to put on the two challenges.

No one won the first competitions, which were held in October 2005.

Related Articles

Elevator to the stars
http://www.newscientist.com/article.ns? ... 125671.900
31 August 2006

Space-elevator tether climbs a mile high
http://www.newscientist.com/article.ns?id=dn8725
15 February 2006

New space prizes target space elevators
http://www.newscientist.com/article.ns?id=dn7201
24 March 2005

Weblinks

LiftPort
http://www.liftport.com

X-Prize Cup
http://www.xprizecup.com

Elevator 2010, Spaceward Foundation
http://www.elevator2010.org/site/index.html

http://www.newscientistspace.com/articl ... print=true

 

[ramonmercado]

Published online: 19 October 2006; | doi:10.1038/news061016-14
Race to space in New Mexico
Space elevator games kick off on Friday.
Katharine Sanderson


An airfield in New Mexico will this weekend host a celebration of space technology: the second annual X Prize Cup games.

The festival is a huge space PR exercise and a showcase for private companies working on space technology. But the main draws are three events that will see space enthusiasts competing for a share of $2.5 million in prize money: the Lunar Lander Challenge, the Vertical Rocket Challenge and the Space Elevator Games.

The lunar lander and vertical rocket competitions are sponsored by NASA, and feed into their ambitions to travel to the Moon. Both contests involve demonstrating an unmanned vehicle that can take off, climb vertically for 50 metres, stay airborne for either 90 (the lander) or 180 (the rocket) seconds, and then land 100 metres from the take-off point.

Experts say the difference in gravity and air pressure between here and the Moon doesn't make too much difference to the design of a lander, and so the games are a good place to test such technology.

Reach for the stars

But the real excitement surrounds the Space Elevator Games, which is split into two $200,000 prizes.

One competition involves making a strong cable of lightweight nanotubes, which is what would be needed to build a real elevator into space. Teams must enter a 2-metre loop of carbon nanotubes no wider than 200 millimetres and no heavier than 2 grams, which will be tested in a tug-of-war. To win, a competitor must have the strongest loop and beat the industry standard of 5.8 Gigapascals by at least 50%.

The real crowd-pleaser is the second half of the elevator games: the climber competition. Entrants must climb a 50-metre ribbon, called the tether, powered only by power beamed from the ground, to cut down on the weight of any fuel or track system.

Last year no team managed to climb the tether. Yet this year, the rules are even tougher. To win climbers must make it to the top carrying a certain amount of weight in 50 seconds or less, and come back down again. "It remains to be seen if anyone can meet all those requirements," says Ted Semon, who is reporting on the games for the official space elevator blog. "I give it at least a 50-50 chance that someone will," he told [email protected].

By the end of Wednesday, four out of 12 teams had got through pre-race qualification. Semon says there's no danger of rival teams stealing each other's ideas. "It's much too late to change anything fundamental," he says. "Each team knows what the others are doing by now. Some teams are even sharing equipment."

Just a game?

But isn't a small device shimmying up a 50-metre ribbon very different from the massive reality of a genuine space elevator?

"The climber challenges are set up to directly crack what really needs to be done," says Brad Edwards, who sits on the board of the Spaceward Foundation, which is overseeing the games. In a few years, he predicts, the tether will be attached to a balloon three kilometres up. This will eventually lead to the real thing, he says — a tether stretching to an anchor in orbit.

Mass space travel is a question not of technology, but money, Edward says. Private finance will drive space exploration, he says, and the space elevator is a cheap way for people to buy in.

The material for the tether remains a contentious issue, and there are debates about whether nanotubes can be made strong and light enough to work. Still, says Edwards, there will always be demand for these strong materials, even though space elevators would be a niche part of the market. "It would be driven by tennis rackets and golf clubs."



Story from [email protected]:
http://news.nature.com//news/2006/061016/061016-14.html

 

[ramonmercado]

Going Up? Will the Japanese be the first to elevate to space?
http://www.popsci.com/military-aviation ... -09/going#
By Paul Adams Posted 09.24.2008 at 5:08 pm 1 Comment

Space Elevator: Most of a rocket’s fuel is spent blasting through Earth’s thick atmosphere and out of the planetâ€s strong gravitational field. But here’s an alternate strategy for getting payloads up to space: Construct a 62,000-mile-long cable jutting straight out from the equator, hold it in place with centripetal force, then lift satellites and spacecraft out of the atmosphere with a giant freight elevator. One major hang-up: Cable strong enough to support the system does not yet exist, though it could be made from carbon nanotubes. Shown above is “The Climber” which sill carry the payload. Photo by John Macneill
One of the most promising technologies for the aspiring outer-space commuter is the space elevator. The concept, like quite a few others, was pressed into the public imagination by Arthur C. Clarke, who in his 1979 novel The Fountains of Paradise described a incredibly thin, incredibly strong carbon filament with one end anchored on Earth and the other extending up to a satellite in geostationary orbit. Now, a group of Japanese scientists are convinced that they can build a space elevator more quickly and cheaply than has been believed possible.

Such a cable could convey cargo into space very cheaply and easily. Carriages would travel up and down the cable under modest power, not the vast expenditures of energy that are currently needed to send anything into orbit.

Technology has crept closer to making it a reality: we have geostationary satellites, and carbon nanotubes promise to be strong and light enough to form the filament, if they can be produced in sufficient quantity. A space elevator would be tens of thousands of miles long.

A few initiatives already exist to make a space elevator a reality. Elevator:2010 sponsors annual contests; LiftPort promises to have an elevator built by October 27, 2031, and is selling tickets on it, at $25/ounce.

The Japan Space Elevator Association, a new player in the field anticipates that Japan's industrial and research power -- "using the technology employed in our bullet trains," according to Association director Yoshio Aoki -- will be able to surmount the outstanding obstacles. The carbon fiber, which needs to have 180 times the tensile strength of steel, is currently under development by Japanese textile companies. The total price tag estimated for erecting the elevator is being estimated at just a trillion yen, or about 10 billion dollars.

 

[ramonmercado]

Japan May Throw Billions At Space Elevator Project
Elevator
by Yury Zaitsev

Moscow (RIA Novosti) Oct 07, 2008
Japanese engineers intend to build an elevator to deliver cargo into space. Japanese authorities are prepared to allocate $10 billion for the project.
The space elevator is expected to cut the cost of delivering cargo into space and is considered one of the most ambitious projects of the 21st century. The Japanese plan to unveil a schedule for the elevator's assembly and commissioning this November.

The idea of a space elevator is over 100 years old. Russia's Konstantin Tsiolkovsky, the founder of theoretical astronautics, suggested building a tower thousands of kilometers high attached to some firmament in orbit. Steel, the most durable material of Tsiolkovsky's time, however, was not capable of bearing even a small part of the expected physical stress.

In 1960, before the first manned flight was performed by Yury Gagarin, Yury Artsutanov, a post-gradate student at the Leningrad Technology Institute, using Tsiolkovsky's ideas, suggested creating a cable-guide connecting a spot on the equator and a space platform in a geostationary orbit at 35,786 km, whose orbit would remain synchronous to that of the location on Earth.

Gravity and centripetal force would keep the cable, connecting the platform to Earth, constantly taut, making transportation possible. The time required for cargo from Earth to reach the platform was estimated at one week.

Later, science fiction writer Arthur Clark wrote of a space elevator in his novel, The Fountains of Paradise, attracting attention to the concept. In 1999, NASA and its Scientific Research Institute included it in the list of probable tasks for early third millennium.

A major problem in the construction of a space elevator is to create the cable, which must be extremely durable and light-weight. The durability of carbon nanotubes, invented in 1991, exceeds the requirements for the space elevator, with a far higher tensile yield strength and density six times less than that of steel.

A one millimeter diameter strand made up of nanotubes is capable of supporting up to 60 metric tons. Still, the technology for industrial production of nanotubes and the weaving of strands into a thread is in its early development.

Some scientists say the inevitable crystal-lattice defects could decrease the durability of the nanotubes. Even if flawless threads could be produced, the micrometeorites, cosmic rays, and atmospheric oxygen could still damage the cable.

Space junk and the natural vibrations of the giant "rope" could also cause the cable to fail.

Another problem is energy supply. Existing battery technology could not provide the necessary energy for the whole distance. This means that an external energy supply will be needed, possibly a laser or microwave source, which will require corresponding receivers to be installed on the elevator itself. Another option would be to use the elevator's braking energy on its way down.

Let us assume that all the problems with materials and energy are solved. The cable weighing thousands of tons has been manufactured, and needs to be placed into space. There are no carrier rockets capable of doing this, which means the cable would have to be launched into space in pieces, which need to be joined somehow afterwards.

Or one could drop down a thin strand from the orbiting platform and splice it into the full diameter of the cable. Neither placement concept seems any easier to implement than creating a suitable material for the cable.

So far scientists have been experimenting in space with cable systems of up to several hundred meters long, made of materials which are far less difficult to produce than nanotubes.

In 1965, Russia's Rocket and Space Corporation Energia, then called the Central Design Bureau for Engineering, led by Academician Sergei Korolev, was preparing the first ever space experiment with a cable system. The project involved creating artificial gravity on the Soyuz spacecraft, which would be connected with the carrier rocket's final stage via a steel cable, both rotating.

After Korolev died, however, the project was cancelled. Development of cable systems was resumed at Energia 20 years later.

A series of experiments with cable systems were performed within U.S., U.S.-Italian and U.S.-Japanese programs. Although some of them failed, part of the planned research was done.

In recent years, scientists at the Space Research Institute of the Russian Academy of Sciences have been researching the possibility of setting up a group of orbital cable systems to ensure cyclic delivery of cargo from Earth to Moon.

Each system will consist of two space vehicles interconnected with a cable and rotating like a slingshot, with its centre of mass moving along a predetermined orbit. If one of the two space vehicles is "unclogged," the rotational energy released will cause its translational movement, like a jet engine.

Theoretical and experimental research has shown that, to keep a transport corridor between Earth and Moon functioning, the design should include three cable systems, two in low earth orbits, low circular and elliptic, and one in a lunar orbit. Cargo would have to be transported between the three systems, eventually making their way to the final destination.

Calculations have revealed that this kind of transport system would weigh 28 times less than the cargo it would be capable of delivering from Earth to Moon, while traditional delivery by a rocket requires an amount of fuel that weighs 16 times more than the cargo itself. This concept would be much simpler and cheaper to implement than a space elevator.

Yury Zaitsev is an academic adviser at the Russian Academy of Engineering Sciences. The opinions expressed in this article are the author's and do not necessarily represent those of RIA Novosti.


Source: RIA Novosti

 

[ramonmercado]

Recent SF novels, eg Marsbound by Joe Haldeman, have featured slow moving space elevators. There are 83 comments (so far) at the article link.

Space elevator trips could be agonisingly slow
www.newscientist.com/article/dn16223-sp ... -slow.html
by Rachel Courtland

The rise of a space elevator could throw its spacecraft "passengers" tens of kilometres off course (Illustration: Pat Rawling/Liftport)
The simple act of climbing could throw space elevators off track and potentially into harm's way, a new study suggests. Fixing the problem could require agonisingly slow trips lasting nearly a month or the careful choreography of multiple climbers.

Space elevators have been proposed as a cheap alternative to expensive rocket launches to send cargo, and perhaps even humans, into space.

The elevators would be made of a cable (also called a tether or ribbon) that would be anchored to the Earth's surface and balanced by a counter-weight in space. Lasers on Earth would beam power to "climbers" that would crawl up the tether with their cargo.

But the concept has been stuck on the ground floor for decades, not least because current materials are not strong enough to handle the strain on the tether. Carbon nanotubes may work, but they need to be longer and purer than those manufactured today.

Even with adequate materials, space elevators might be highly unstable. Gravitational tugs from the Moon and Sun, as well as pressure from gusts of solar wind, could shake the tether, potentially causing the elevator to crash into nearby satellites or space junk. Thrusters might be needed to keep the tether in line.

Now, it seems that the act of climbing itself could also cause the tether to wobble.

Earth's spin
The culprit is the Coriolis force, which deflects objects that are moving in a rotating system. On Earth, the planet's rotation sets up a Coriolis force that deflects air currents and water.

In this study, the space elevator would stand vertically from a point on Earth's equator. As the climber ascended, its motion would cause the Coriolis force to pull the climber, and thus the cable, in the opposite direction of Earth's rotation.

This would pull the elevator away from its vertical resting position, causing it to oscillate back and forth like a pendulum, say mechanical engineers Arun Misra of McGill University in Montreal, Canada, and Stephen Cohen, now at MDA Space.

Wrong orbits
The motion of cargo up the elevator might only cause the cable to wobble back and forth by a fraction of a degree, says Misra.

But the tether's swing could either boost or reduce the velocity of any spacecraft exiting the elevator. That could send them into orbits that are tens of kilometres too high or too low, Misra says, adding that significant amounts of fuel might be needed to correct the problem.

"Because it's a huge structure, this small deviation can make large errors in the orbit that will be reached by the payload," Misra told New Scientist.

The wobbles induced by climbing cargo might also help send the elevator into harm's way.

Slow crawl
The faster a climber goes, the larger the effect, Misra told New Scientist, so the simplest way to minimise a climber's effect on the cable is to slow its ascent.

Slowing the climb would allow the space elevator to be drawn back to its stable point, perfectly vertical above the Earth's equator. But this could also make trips into orbit agonisingly slow, adding nine days or more to a climb that – at several hundred kilometres per hour – might already take about 15 days.

Alternatively, the speed of climbs might be fine-tuned as the trip progresses, Misra says. Multiple climbers could also be sent up the tether at the same time, in a carefully orchestrated ballet.

"I think we are finding that building a space elevator is a lot more complicated than simply stringing up a ribbon and whizzing up and down it," says Anders Jorgensen of the New Mexico Institute of Mining and Technology in Socorro, US, who has studied space elevator stability.

Speed limit
"Needing to impose a particular climber schedule and speed could have implications for the economical viability of a space elevator, so it is a very important question to answer," Jorgensen says.

"Traffic-phasing will likely play a role," agrees David Lang, a consultant based in Seattle, Washington, who has also studied the effects of climbers.

But other methods, involving coupled space elevators arranged side by side or one-way traffic that occasionally reverses direction, might also help. "I would say that it is too early to establish the best way to do this," Lang told New Scientist.

Journal reference: Acta Astronautica (forthcoming)http://dx.doi.org/10.1016/j.actaastro.2008.10.003

For similar stories, visit the Spaceflight Topic Guide
http://www.newscientist.com/topic/spaceflight

 

[rynner2]

Going up ... and the next floor is outer space
An elevator ride into space could become more than sci-fi fantasy, thanks to a British breakthrough
Joseph Dunn

Ever since it was first popularised by Arthur C Clarke, the idea of a “space elevator” has languished in the realms of science fiction. But now a team of British scientists has taken the first step on what could be a high-tech stairway to heaven.

Spurred on by a $4m (£2.7m) research prize from Nasa, a team at Cambridge University has created the world’s strongest ribbon: a cylindrical strand of carbon that combines lightweight flexibility with incredible strength and has the potential to stretch vast distances. The development has been seized upon by the space scientists, who believe the technology could allow astronauts to travel into space via a cable thousands of miles long — a space elevator.

They predict the breakthrough will revolutionise space travel. It has a point, though at this stage it is still a tenuous one. Such an elevator could potentially offer limitless and cheap space travel. At a stroke, it would make everything from tourism to more ambitious expeditions to Mars commercially viable. The idea couldn’t come too soon for Nasa, which spends an estimated £308m every time the shuttle blasts off, not to mention burning about 900 tons of polluting rocket fuel.

The American space agency is already staring at a black hole in its finances that means it will not replace its ageing shuttle fleet — due to retire in 2010 — until 2014 at the earliest. Without its own transport, Nasa has recently contracted private firms such as SpaceX, headed by Elon Musk, the internet entrepreneur, to provide transport to and from the International Space Station. The idea of an elevator could solve the problem — although perhaps not quickly enough for Nasa.

The Cambridge team is making about 1 gram of the high-tech material per day, enough to stretch to 18 miles in length. “We have Nasa on the phone asking for 144,000 miles of the stuff, but there is a difference between what can be achieved in a lab and on an industrial level,” says Alan Windle, professor of materials science at Cambridge University, who is anxious not to let the work get ahead of itself.

Enthusiasts say space elevators will be able to lift material more than 22,000 miles into orbit for as little as £300 per pound weight, compared with about £14,000 per pound using existing rockets. That would open up the possibility of tourists visiting a sky hotel in orbit, with a view previously enjoyed only by astronauts. It would also allow for far cheaper travel to the moon and planets since most of the energy required by rockets is used simply to escape Earth’s gravity.

The concept of a lift into space was first proposed in 1895 by Konstantin Tsiolkovsky, a Russian scientist who was inspired by the Eiffel tower. The idea continued to be batted around in scientific circles until the late 1970s when Clarke based his novel The Fountains of Paradise on the idea. In it he asked: “If the laws of celestial mechanics make it possible for an object to stay fixed in the sky, might it not be possible to lower a cable down to the surface and so establish an elevator system linking Earth to space?”

At the time the answer was a resounding “no”, and Clarke admitted the idea would be met with laughter for years to come, but over the past decade the concept has moved from the fringes of the scientific establishment towards the mainstream.

The theory sounds plausible: a cable is extended up to a station 22,245 miles into space — the point at which satellites stay in geostationary orbit — and kept under tension by the competing forces of gravity on Earth and the outward centrifugal acceleration at the platform end. The cable then extends a further 40,000 miles into space to a counterweight that helps keep the whole structure stable. An elevator is attached and powered up the cable much like a train on a celestial track.

The idea is still in the realms of science fiction, and no one is expecting it to become a reality for at least another decade, but the concept is gaining currency. Last year saw the formation of the International Space Elevator Consortium, an independent group designed to promote the idea.

Nasa has pledged $4m over five years from its Centennial Challenges programme to the Elevator: 2010 competition. The contest challenges teams to build working scale models of an elevator that can travel 1km vertically upwards at a minimum speed of 2 metres per second. The best performance so far is just 100 metres at a speed of 1.8 metres per second. The next challenge is scheduled for April.

“We are talking about something totally different from the conventional concept of space travel,” says Ben Shelef, chief executive officer of the Spaceward Foundation, Nasa’s partner in the project. “This is not about three astronauts on a special mission, it is about hundreds of tons a day being lifted into orbit. I often say that we shouldn’t be dealing with Nasa on this, we should be dealing with the US Department of Transportation.”

Shelef’s plans have big long-term goals. “It will start with supplies, but many of the world’s problems are due to overcrowding so eventually we see the elevator as a way of shifting human life off Earth and into space.”

Given the distance any cable would have to stretch and the stresses it is under at the top to support its own weight, it would need to taper as it reaches Earth. A conventional cable that is one strand thick at Earth level would therefore be about as wide as the whole planet at 22,000 miles. And this is the problem the Cambridge team thinks it may have solved.

The discovery in the 1990s of “nanotubes” (a cylindrical version of carbon) meant that for the first time a material strong and light enough was possible. However, these nanotubes proved too brittle to be formed into long strands. The Cambridge team has found a way of combining separate nanotubes into web-like structures that bind to form longer strands.

“The key thing is that the process essentially makes carbon into smoke, but because the smoke particles are long thin nanotubes, they entangle and hold hands. We are actually making elastic smoke, which we can then wind up into a fibre,” says Windle.

He also suggests the technique has enormous possibilities — many of them more mundane — for everything from bulletproof vests to car manufacture. However, it is the possibility that it could be used for a space elevator that excites him. “It is an eye-catching idea, and you have to aim high,” he says, adding that the creation of material strong enough for such an idea is about five to 10 years away.

The team’s results were outlined at a conference last month in Luxembourg, which gathered together hundreds of futurists, Nasa researchers and representatives of the European Space Agency. John Winter of EuroSpaceward, the agency that organised the conference, says the advance proves the idea of stretching a cable, or tether, from the Earth to a station in space, along which a vehicle can travel, is closer to becoming a reality than previously thought.

“The biggest problem has always been finding a material that is strong enough and lightweight enough to stretch tens of thousands of miles into space,” says Winter. “This isn’t going to happen probably for the next decade at least, but in theory this is now possible. The advances in materials for the tether are very exciting.”

http://www.timesonline.co.uk/tol/drivin ... 529668.ece

Coincidentally, I'm currently reading Arthur C Clarke's last book, "The Last Theorem", which also involves a space elevator.

 

[ramonmercado]

The Last Therom is an interesting book but not his best. More of a political thriller.

 

[Pete Younger]

I think it's been mentioned before, wouldn't it be a target for terrorists?

 

[rynner2]

Terrorists are so mind-f*cked that anything can seem a good target...

 

[ramonmercado]

I think it's been mentioned before, wouldn't it be a target for terrorists?

In Ken McLeods novel, The Night Sessions, Robot terrorists target a space elevator.

 

[ramonmercado]

Climbing Into Space By The Rope
www.space-travel.com/reports/Climbing_I ... e_999.html

Konstantin Tsiolkovsky talked about an elevator into space in 1895. In 1960, Soviet engineer Yury Artsyutanov published an article in which he set forth in detail the concept of such a space elevator and noted an enormous economic effect that it could produce. However, at that time no equipment could produce the materials of the required durability and mass.
by Andrei Kislyakov

Moscow (RIA) Feb 19, 2009
There is no limit to human imagination when it comes to reaching heights. Sometimes, a miraculous elixir makes it possible to fly in the skies with a crazy speed, or there appear space ships, counterparts of aircraft with unlimited potentialities.
We also know about more primitive fancies, when something grows on Earth to such a height that space seems to be near.

It is this latter primitive version that is most likely to be translated into reality. It amounts to a space elevator. The program for its development has been recently carried out much faster owing to progress in the production of super-durable light materials.

Let's imagine a simple picture. Someone has tied up a stone to the end of a rope and is twisting it around. The stone rotates, and the rope is stretched out under the impact of the centrifugal force. Let's imagine one end of the rope is fixed at the equator, and the other is tied up to a satellite.

The centrifugal force won't allow the rope to fall on Earth. The gravity decreases in proportion to the square of distance, while the centrifugal force grows with an increase in the distance.

Calculations show that at the height of about 42,000 km this force will be equal to gravity. If we make a wire rope of that length, we will get a direct roadway from Earth to space.

This is not at all a fantastic idea. It is based on simple physical laws. Serious researchers could not get a peace of mind because of its simplicity for a long time.

Konstantin Tsiolkovsky talked about an elevator into space in 1895. In 1960, Soviet engineer Yury Artsyutanov published an article in which he set forth in detail the concept of such a space elevator and noted an enormous economic effect that it could produce. However, at that time no equipment could produce the materials of the required durability and mass.

This time NASA specialists rather than Russian scientists have come back to this idea. In August 2000 they published a project whereby several super-durable 35,000 km-long wire ropes are fixed to the upper end of a giant 50 km-high ground-based tower.

In space, the wire ropes are tied up to a special satellite. Platforms on electromagnetic engines will move by the wires to carry astronauts and loads.

Making wire ropes was the only problem, but it seems British experts have resolved it. Nanotechnologists from Cambridge have developed a flexible and very durable light carbonic thread. For the time being, they can only make one gram of this material per day, which is enough to spread the thread for 29 km.

A space elevator will require 232,000 km of the thread. It will take more than a decade before it is launched.

In NASA's estimate, the project will cost more than $10 billion, but the game is still worth the candle. Experts believe that it will cost no more than $1.5 to get one kilo of a load to space because of the space elevator's low operational expense.

Obviously, the construction of a space elevator will become the most grandiose project in human history. A tremendous amount of scientific, technical, material and political problems will make it possible only on condition of close international cooperation.

The opinions expressed in this article are the author's and do not necessarily represent those of RIA Novosti.


Source: RIA Novosti

 

[ramonmercado]

Elevator to space? They're really trying
http://www.physorg.com/news176545232.html
November 4, 2009
The 2009 Space Elevator Games.

(AP) -- Rocketing into space? Some think an elevator might be the way to go. That's the future goal of this week's $2 million Space Elevator Games in the Mojave Desert.


In a major test of the concept, robotic machines powered by laser beams will try to climb a cable suspended from a helicopter hovering more than a half-mile (one kilometer) high.

Three teams have qualified to participate in the event on the dry lakebed near NASA's Dryden Flight Research Center at Edwards. Attempts were expected from early Wednesday through Thursday.

Funded by a space agency program to explore bold technology, the contest is a step toward bringing the idea of a space elevator out of the realm of science fiction and into reality.



Theorized in the 1960s and then popularized by Arthur C. Clarke's 1979 novel "The Fountains of Paradise," space elevators are envisioned as a way to gain access to space without the risk and expense of rockets.

Instead, electrically powered vehicles would run up and down a cable anchored to a ground structure and extending thousands of miles up to a mass in geosynchronous orbit - the kind of orbit communications satellites are placed in to stay over a fixed spot on the Earth.

Electricity would be supplied through a concept known as "power beaming," ground-based lasers pointing up to photo voltaic cells on the bottom of the climbing vehicle - something like an upside-down solar power system.

The space elevator competition has not produced a winner in its previous three years, but has become increasingly difficult.

The vehicles must climb a cable six-tenths of a mile into the sky and move at an average speed of 16.4 feet (five meters) per second.

The competition is sponsored by the nonprofit Spaceward Foundation with support from NASA's Centennial Challenges program.

 

[ramonmercado]

And the winner is...

'Space elevator' wins $900,000 NASA prize
http://www.newscientist.com/article/dn1 ... prize.html
23:37 06 November 2009 by David Shiga

A laser-powered robotic climber has won $900,000 in a competition designed to spur technology for a future elevator to space.

Building a space elevator would require anchoring a cable on the ground near Earth's equator and deploying the other end thousands of kilometres into space. The centrifugal force due to Earth's spin would keep the cable taut so that a robot could climb it and release payloads into orbit.

Though building a space elevator might require an initial investment of billions of dollars, proponents say once constructed, it would make for cheaper trips into space than is possible using rockets. But huge technological hurdles must first be overcome, including how to supply power to the robotic climber.

To that end, NASA offered $2 million in prize money in a competition called the Power Beaming Challenge, in which robotic climbers, powered wirelessly from the ground, attempt to ascend a cable as fast as possible.

Now, a robotic climber has made a prize-winning ascent worth $900,000, making it the first to win money in the competition, which has occurred annually since 2005.

Ted Semon, a volunteer with the Spaceward Foundation, a non-profit that organised the competition, and author of the Space Elevator Blog, says the feat shows space elevators are one step closer to getting off the ground. "We've done a lot here to demonstrate that this technology is possible," he told New Scientist. "This is just enormously exciting."

The winning climber was built by a team called LaserMotive, based in Seattle, Washington. Like the other two vehicles in the competition, it used solar cells to absorb energy from a ground-based infrared laser.

Unclaimed pot
On Wednesday, LaserMotive fired up its laser, powering the climber to ascend 900 metres up a cable suspended from a helicopter at Edwards Air Force Base in Mojave, California.

The climber reached the top in just over 4 minutes, for an average speed of 3.7 metres per second. The team's climber repeated the feat at a slightly higher speed of 3.9 metres per second on Thursday.

On Friday, two other teams failed in their final attempted climbs. That means LaserMotive will receive the entire $900,000 NASA set aside for climbers that could make the climb faster than 2 metres per second.

The remaining $1.1 million in NASA prize money was reserved for climbs faster than 5 metres per second, which none of the competitors was able to achieve.

Lunar rovers
A climber entered by a team from the University of Saskatchewan in Saskatoon, Canada, stalled just a few metres up the cable in its final attempt on Friday and was unable to continue its climb.

A climber from a third team, called the Kansas City Space Pirates, also achieved only partial climbs.

NASA was expected to officially recognise LaserMotive as the winner of the $900,000 prize in an award ceremony later on Friday.

Though a space elevator remains a distant prospect, NASA is interested in wireless power transmission for other applications, like beaming power to lunar rovers travelling in shadowed craters, where solar energy is unavailable.

 

[ramonmercado]

Why Don't We Have Space Elevators Yet?
http://www.space.com/21271-space-elevat ... lenge.html
Jillian Scharr, TechNewsDaily Staff WriterDate: 23 May 2013 Time: 07:00 AM

Concept art of a space elevator, by Alan Chan.
CREDIT: Alan Chan, SpaceElevator.com

With his 1979 novel "The Fountains of Paradise," science-fiction writer Arthur C. Clarke introduced the idea of space elevators to the mainstream scientific community and the general public.

The fundamental principle hasn't changed much in more than 40 years: A space elevator would consist of a powerful cable, or tether, anchored on one end to the Earth and on the other to a counterweight in geosynchronous orbit with Earth.

A space elevator could easily get people and materials into space at a fraction of the energy and cost a rocket launch requires. Instead of burning expensive fuel to launch heavy objects off of Earth's surface, the elevator could convey them up the tether past lower Earth orbit and into space.


It's an idea that is both fantastical and practical, and it has captured the imagination of scientists and nonscientists alike. So where are all the space elevators?

It's not like people aren't working on it. The International Space Elevator Consortium (yes, it's a thing) will focus on tether climbing technologies at its annual conference this August in Seattle. And rumor has it that space elevators are one of many futuristic projects under development at Google's secretive Google X labs.

But the real reason space elevators only exist in science fiction is simple: We can't build them. Not yet.

"The problem with space elevators is strength of materials," said Jim Crocker, vice president of civil space at Lockheed Martin, where he's working to develop the United States’ next manned spacecraft, called the Orion.

"You have to envision a cable that you could deploy in space and then drop down to Earth and anchor somewhere, and run things up and down," Crocker said, speaking hypothetically about what it would take to make a space elevator.

Scientists have yet to discover a method for creating a material that would be both strong enough and flexible enough to serve as the cable.

It is currently possible to make nanomaterials that are up to a hundred times stronger than the strongest steel at a fraction of the weight. The problem is, once you try to build at a scale bigger than a few microns, the nanomaterials’ strength and stiffness start to decrease.

[See also: What is Nanotechnology?]

“The moment you start connecting [nanotubes] together — braid[ing] it or something that's not a continuous link — it doesn't have the same properties at that level that it had at the nanoscale,” said Suraj Rawal, a research scientist at Lockheed Martin.

So the design question that has to be answered before Earth-based space elevators can become a reality is, how do you go from the nanoscale to the macroscale and still retain all the same properties?

The question has scientists puzzled for now, but Arthur C. Clarke would say it's only a matter of time before space elevators become a reality. As he wrote in 1962: "The only way of discovering the limits of the possible is to venture a little way past them into the impossible."

 

[rynner2]

Inflatable ‘space elevator’ invented by scientists
Astronauts would ascend 12 miles into the stratosphere before taking off under new plans to build a space lift
By Sarah Knapton, Science Editor
1:43PM BST 16 Aug 2015

It is an idea that every small child has had at some point. Instead of sending up rockets into space, why not simply build a huge lift.
Now a Canadian firm has been granted a patent for a ‘space elevator’ which will shoot cargo 12.4 miles into the stratosphere from where it can be launched more easily.

According to Thoth Technology, the lift would cut the cost of space flight by around one third because shuttles would not need to carry enormous amounts of fuel to get themselves off the ground.
“Astronauts would ascend to 12 miles by electrical elevator,” said Dr Brendan Quine, the inventor.
“From the top of the tower, space planes will launch in a single stage to orbit, returning to the top of the tower for refuelling and reflight.”

...

Engineers had always believed that space elevators would be unfeasible because no material exists which could support itself at such a height - although diamond nano-threads have been suggested.
However the new design by Thoth gets around the problem by only building the elevator to 12.4 miles so that it sits in the stratosphere rather than going all the way out into geostationary orbit, where satellites fly, which is around 22,000 miles up.

etc...

http://www.telegraph.co.uk/news/sci...le-space-elevator-invented-by-scientists.html

 

[Mythopoeika]

I can imagine the sheer amount of wobble on such a tall structure. Unless... they use gyroscopes or some other technique to stabilise it.

 

[Naughty_Felid]

A good band name OTIS & The Space Elevators

 

[GNC]

A good band name OTIS & The Space Elevators

Too close to The 13th Floor Elevators or The Frantic Elevators.

 

[Naughty_Felid]

Too close to The 13th Floor Elevators or The Frantic Elevators.

So with that logic, The Stray Cats, Pole Cats, Hep Cats, Flat Cats, Herding Cats, Swing Cats, Dead Cats, Taco Cats, Cat Stevens, Cat Power, The Pussy Cats Dolls and even Lion-el Ritchie should have just not bothered?

fool.

 

[Ulalume]

Too close to The 13th Floor Elevators or The Frantic Elevators.

Maybe, maybe not, but I am impressed by your reference to the 13th Floor Elevators.

Anyway, if there's ever a space elevator, I'm totally going. While I have no desire to be hurtled into space on a rocket, if there's an elevator, hell yeah.

 

[escargot]

Pictures of Thoth Technology's patented lift has just been shown on the BBC news. It will apparently save a third on fuel costs. That's until terrorists blow it up or fly planes into it.

 

[eburacum]

How does an inflatable elevator get you any closer to orbital speed?

 

[rynner2]

How does an inflatable elevator get you any closer to orbital speed?

It doesn't, much. But it does get you above most of the atmosphere, and ground launched rockets expend most of their fuel getting through the dense lower atmosphere.

From 12 miles up you can take off on the runway and then accelerate to orbital speed in a gentle climb.

No doubt Thoth have done all the calculations!

(I can't return to check out the full article because the Telegraph today says I've reached my 15 article limit! )