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 ")
Is China Mining Helium-3 On The Moon's Farside?
'...for months Grantline bores had dug into the cliff.' -
Solitary Black Hole Wanders In Space
'...the Hole is something like a vortex or a whirlpool?' - Frank K. Kelly, 1935.
Spaceplane From Virgin Atlantic
'ZARNAK, YOU'RE TO COMMAND A SCOUTING EXPEDITION --- FIND OUT WHAT THIS IS ALL ABOUT!'
Taikonauts Exercise In China's Tiangong Space Station
'Joe got out the gravity-simulator harnesses...' - Murray Leinster, 1953.
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
LLM 'Cognitive Core' Now Evolving
'Their only check on the growth and development of Vulcan 3 lay in two clues: the amount of rock thrown up to the surface... and the amount of the raw materials and tools and parts which the computer requested.'
Has Elon Musk Given Up On Mars?
'There ain't no such thing as a free lunch.'
Bacteria Turns Plastic Into Pain Relief? That Gives Me An Idea.
'I guess there's nobody round this table who doesn't have a Crosswell [tapeworm] working for him in the small intestine.'
When Your Child's Best Friend Is An AI
'Figments of his mind in one sense, of course, for he had shaped them...'
China's Drone Mothership Can Carry 100 Drones
'So the parent drone carries a spotter that it launches...'
Drones Recharge In Mid-Air Like Jets Refuel!
'...nurse drones that would cruise around dumping large amounts of power into randomly selected pods.'
Australian Authors Reject AI Training Of Llama
'It's done with a flip of the third joint of the tentacle on the down beat.'
Is China Mining Helium-3 On The Moon's Farside?
'...for months Grantline bores had dug into the cliff.'
Maybe It's Too Soon To Require Autonomous Mode
'I hope all those other cars are on automatic,' he said anxiously.
Is Agentic AI The Wrong Kind Of Smartness?
'It’s smart enough to go wrong in very complicated ways, but not smart enough to help us find out what’s wrong.'
Heat Waver - The First Ever Combo Solar Collector And Wind Turbine
'...like a spray of tulips mounted fanwise.'
Tesla 'Fleet Response Agents' Bolster FSD Autonomy
'You hate the whole idea that some bored drone pusher in a remote driving centre has got your life... in his hands.'
Mori3 Autonomous Shapeshifting Robot
'My homeland is being threatened by the Replicators. Thus far all attempts to stop them have failed.'
Tesla Seeks 'Tesla Robotaxi' And 'Robobus' Trademarks Ignoring Prior Art
'A robobus had just rolled up to the curb.'
Scary Grid Safety Robots
'The ultimate horror for our paranoid culture...'
Does AI Provide A Way Forward For Talk Therapy
'And there in the next room by the sofa sat a familiar suitcase, that of his psychiatrist Dr. Smile.'
