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 ")
SpaceX's Starman Tesla Roadster In Space
'Somewhere in space, a chrome and blue automobile raced the green light of Earth.' - Theodore Sturgeon, 1941.
Warp Drive Tech Back On The Menu
'Detailed plans for the construction of the Gundstetter-Halone warp drive were flowing.' - RM Williams, 1940.
JAXA Int Ball 2 Coming Right Along As Star Wars Remote
'Hocus-pocus religions and archaic weapons are no substitute for a good blaster at your side.' George Lucas, 1976.
Space Traffic Management (STM) Needed Now
'...the spot was a lonely one in an uncharted region, far from the normal lanes of space traffic.' - Arthur William Bernal (1935)
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
Nuclear Plant Restarted To Power AI To Feed Us Dreams
'...Anything was possible in my imaginary environment.'
SpaceX's Starman Tesla Roadster In Space
'Somewhere in space, a chrome and blue automobile raced the green light of Earth.'
Pivotal Blackfly Electric Aircraft Lifts And Hovers
'That explains how it was so easy for me to remain motionless in midair...'
CORLEO Robotic Horse Concept Looks Ready To Ride
Imagine digging your heels in to a steam horse!
Who First Thought Of A Tin Foil Hat?
'We had discovered that metal was relatively impervious to the telepathic effect.'
Warp Drive Tech Back On The Menu
'Detailed plans for the construction of the Gundstetter-Halone warp drive were flowing.'
Huawei Pura X Folding Phattie Phone
Why can't we get more innovative phone configurations?
Sleep Pods At Daxing International Airport
'Do not waste your priceless company on the unappreciative folds of a sleep pod...'
Robot Baristas Learn Their Trade Without Paying Royalties
'...so we've promised him a generous pension from the royalties.'
JAXA Int Ball 2 Coming Right Along As Star Wars Remote
'Hocus-pocus religions and archaic weapons are no substitute for a good blaster at your side.'
Robot Bricklayer Or Passer-By Bricklayer?
'Oscar picked up a trowel. 'I'm the tool for the mortar,' the little trowel squeaked cheerfully.'
Robot Gas Station Attendant Pumps Gas For You
'... he waited for the robotrix attendant to finish fueling up his ship.'
Engineer Creates Crazy Motorized Track Hospital Bed
The Roujin Z system provides care to fully bedridden patients - and then some!
Tiny Flying Robot Weighs Just One Gram
'Aerostat meant anything that hung in the air. This was an easy trick to pull off nowadays.'
Some Ringworld Configurations Are Stable
'The Ringworld had no horizon. There was no line where the land curved away from the sky.'
TRANSFORM Dynamic Furniture Concept Becomes What You Need
'An adjustment panel outside the door would cause it to extrude various appurtenances in memory plastic...'
