Science Fiction Dictionary
A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z

 

Space Elevator Downer

Scientists and science fiction fans alike have big plans for carbon nanotubes; it has been hoped that a cable made of carbon nanotubes would be strong enough to serve as a space elevator. However, recent calculations by Nicola Pugno of the Polytechnic of Turin, Italy, suggest that carbon nanotube cables will not work.


(Looking down a carbon nanotube)

American engineers worked on the problem in the mid-1960's. What type of material would be required to build a space elevator? According to their calculations, the cable would need to be twice as strong as that of any existing material including graphite, quartz, and diamond.

Science fiction writer Arthur C. Clarke recognized the materials problem; his ingenuity was equal to the task of creating just such a material. In his excellent 1978 novel The Fountains of Paradise, he thought up a special form of carbon, something called a "continuous pseudo-one dimensional diamond crystal," to serve as the cable material. To the delight of sf fans and aerospace engineers, Japanese researcher Sumio Iijima (at NEC) discovered carbon nanotubes, which are cylindrical carbon fibers exhibiting strength 100 times greater than that of steel at one sixth the weight, and high strain to failure.

In something of a "downer" for space elevator fans, Pugno has calculated that inevitable defects will greatly reduce the strength of any manufactured nanotubes. Laboratory tests have demonstrated that flawless individual nanotubes can withstand about 100 gigapascals of tension; however, if a nanotube is missing just one carbon atom, it can reduce its strength by as much as thirty percent. Bulk materials made of many connected nanotubes are even weaker, averaging less than 1 gigapascal in strength.

In order to function, a space elevator ribbon would need to withstand at least 62 gigapascals of tension. It therefore appears that the defects described above would eliminate carbon nanotubes as a usable material for a space elevator cable. Pugno will publish his paper in the July edition of Journal of Physics: Condensed Matter. Nanotube enthusiasts counter that ribbons made of close-packed long nanotubes would demonstrate cooperative friction forces that could make up for weaknesses in individual nanotubes.

Read more about Arthur C. Clarke's one-dimensional diamond crystal; in Carbon Nanotube Ribbon for Space Elevator a method of creating meter-long nanotube ribbons is described. A robotic lifter that would traverse a space elevator ribbon has also been tested. Read more about the current controversy at Nature.

Scroll down for more stories in the same category. (Story submitted 5/26/2006)

Follow this kind of news @Technovelgy.

| Email | RSS | Blog It | Stumble | del.icio.us | Digg | Reddit |

Would you like to contribute a story tip? It's easy:
Get the URL of the story, and the related sf author, and add it here.

Comment/Join discussion ( 13 )

Related News Stories - (" Space Tech ")

ESA To Build Moon Bases Brick By Printed LEGO Brick
'We made a crude , small cell and were delighted - and, I admit, somewhat surprised - to find it worked.' - John W. Campbell, 1950.

FLOAT Levitating Train On The Moon ala Clarke
'The low-slung monorail car, straddling its single track, bored through the shadows on a slowly rising course.' - Arthur C. Clarke, 1955.

SpaceX Intros Extravehicular Activity Suit
'Provision had been made to meet the terrific cold which we knew would be encountered the moment we had passed beyond the atmosphere.' - Garrett P. Serviss, 1898.

SpaceX Wants A Moonbase Alpha
'And he had been sent with troops, supplies and bombs to command Russia's most trusted post, the Moonbase.' - L. Ron Hubbard, 1948.

 

Google
  Web TechNovelgy.com   

Technovelgy (that's tech-novel-gee!) is devoted to the creative science inventions and ideas of sf authors. Look for the Invention Category that interests you, the Glossary, the Invention Timeline, or see what's New.

 

 

 

 

Science Fiction Timeline
1600-1899
1900-1939
1940's   1950's
1960's   1970's
1980's   1990's
2000's   2010's

Current News

Shanghai Guidelines For Humanoid Robots
'Now, look, let's start with the three fundamental Rules of Robotics...'

Desktop TARS Robot From Interstellar
What's YOUR sarcasm setting?

Robots Can Now Have Smiling Faces With Human Skin
'I am a cybernetic organism...'

Virtual Rat Predicts Actual Rat Neural Activity
'..the synthetic intellects at the Place of Knowledge had far outstripped the minds of men.'

GoSun EV Solar Charger Drapes Onto Your Car
'...six square yards of sunpower screens.'

Rizon 4 Ironing Robot
'But after washing and drying clothes had to be smooth - free from fine lines and wrinkles ...'

Cognify - A Prison Of The Mind We've Seen Before In SF
'So I serve a hundred years in one day...'

Robot With Human Brain Organoid - 'A Thrilling Story Of Mechanistic Progress'
'A human brain snugly encased in a transparent skull-shaped receptacle.'

Goodness Gracious Me! Google Tries Face Recognition Security
'The actuating mechanism that should have operated by the imprint of her image on the telephoto cell...'

With Mycotecture, We'll Just Grow The Space Habitats We Need
'The only real cost was in the plastic balloon that guided the growth of the coral and enclosed the coral's special air-borne food.'

Can A Swarm Of Deadly Drones Take Out An Aircraft Carrier?
'The border was defended by... a swarm of quasi-independent aerostats.'

WiFi and AI Team Up To See Through Walls
'The pitiless M rays pierced Earth and steel and densest concrete as if they were so much transparent glass...'

Climate Engineering In California Could Make Europe's Heat Waves Worse
'Pina2bo would have to operate full blast for many years to put as much SO2 into the stratosphere as its namesake had done in a few minutes.'

Optimus Robot Will Be A Good Nanny, Says Musk
'Nanny is different,' Tom Fields murmured... 'she's not like a machine. She's like a person.'

ESA To Build Moon Bases Brick By Printed LEGO Brick
'We made a crude , small cell and were delighted - and, I admit, somewhat surprised - to find it worked.'

Does The Shortage Of Human Inputs Limit AI Development?
'...we've promised him a generous pension from the royalties.'

More SF in the News Stories

More Beyond Technovelgy science news stories

Home | Glossary | Invention Timeline | Category | New | Contact Us | FAQ | Advertise |
Technovelgy.com - where science meets fiction™

Copyright© Technovelgy LLC; all rights reserved.