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
 |
Solar-Photon Hoop Sails For Extrasolar Travel
The solar-photon hoop sail idea was once again advanced by CUNY physicist Gregory Matloff at the Second Solar Sail Symposium held last month in New York City.
The idea for hoop-shaped solar sails was first placed before a larger audience (and specifically the sf community) in a 1951 paper Clipper Ships of Space, published in Astounding Science Fiction by engineer Carl Wiley. The idea of a starlight sail or light sail was later picked up by sf writer Cordwainer Smith in his 1960 story The Lady Who Sailed The Soul. which explicitly details the use of solar sails in extrasolar travel. Matloff provides an analysis of this possibility in his paper.
Just two years later, in 1962, Jack Vance published Sail 25, an excellent short story that provides a fairly meticulous description of a hoop sail:
In the story, Vance ups the ante for a group of space cadets under the tutelage of grizzled spaceman Henry Belt, making it clear that poor solar sailing could result in visiting the outer planets or even leaving the solar system entirely.
Matloff concludes:
Take a look at Matloff's paper The Hoop Solar-Photon Sail and Extrasolar Travel (PDF) via Centauri Dreams via Atomic Rockets.
A solar-photon hoop sail consists of a thin reflective membrane within a supporting, possibly inflatable hoop. Hoop sails may be an alternative to parachute and hollow-body sails for extra-solar application. In all likelihood, payload would be suspended from the rim... Hoop sails appear to have competitive performance to parachute and hollow-body sails. They are easier to deploy than parachute sails, and are less susceptible to micrometeoroid damage than hollow-body sails. Scaling hoop sails from small test items to very large radii seems possible.
(From The Hoop Solar-Photon Sail and Extrasolar Travel [PDF})
Massaging the numbers for a hoop sail to deep space, Matloff comes up with a ‘sundiver’ trajectory that allows a hoop sail spacecraft to exit the Solar System at about 635 kilometers per second (130 AU per year). This is sufficient to reach the inner fringe of the Oort Cloud in several decades, while a crossing to the Centauri system would involve 2,000 years. That’s about twice the time for an optimized mission with a space-manufactured sail.
(From Hoop Sails: An Interstellar Possibility? [Centauri Dreams])
The pressure of radiation, of course, is extremely light - on the order of an ounce per acre at this distance from the sun. Necessarily, the sail must be extremely large and extremely light. We use a fluro-siliconic film a tenth of a mil in gauge, fogged with lithium to the state of opacity. Such a foil weighs about four tons to the square mile. It is fitted to a hoop of thin-walled tubing, from which mono-crystalline iron cords lead to the hull.
(Read more about Vance's hoop light sail)
The performance of a hoop sail will be competitive with other solar-photon-sail interstellar configurations. The payload fraction is lower than that of certain other configurations, which may not be a disadvantage since sail mass can be used as cosmic-ray shielding during the interstellar cruise.
Advantages of the hoop sail over the parachute sail include scalability and ease of deployment. The hoop sail is less susceptible to micrometeoroid-caused deflation than the hollow-body sail.
A ripstop array is almost certainly necessary to prevent sail ripping due to micrometeoroid impacts. Such an array will increase total mass spacecraft mass and degrade performance by only a few percent.
The work presented here should be viewed as a very preliminary analysis. Much additional research is required before interstellar hoop sails can be declared feasible.
(From The Hoop Solar-Photon Sail and Extrasolar Travel [PDF})
Scroll down for more stories in the same category. (Story submitted 8/13/2010)
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 ( 0 )
Related News Stories - (" Space Tech ")
SpaceX EVA Spacesuit Tested By Polaris Dawn Crew
'Now, except for weight and heat, the same conditions prevail in this chamber as in space.' - Otto Willi Gail, 1929.
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.
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
Chaffeur Robot Musashi Will Drive Your Regular Car
'What would you do,' Eric asked the robot cabdriver, 'if your wife had turned to stone, your best friend were a toad, and you had lost your job?'
Space Exporers! Now, You Can Drink Your Own Urine
'those suits they wear -- call them 'stillsuits' -- that reclaim the body's own water...'
SpaceX EVA Spacesuit Tested By Polaris Dawn Crew
'Now, except for weight and heat, the same conditions prevail in this chamber as in space.'
Automatic Bot Traffic Is 38 Percent Of HTTP Requests
'there were so many worms and counterworms loose in the data-net...'
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...'
