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.

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})

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.

Massaging the numbers for a hoop sail to deep space, Matloff comes up with a Ďsundiverí 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. Thatís about twice the time for an optimized mission with a space-manufactured sail.
(From Hoop Sails: An Interstellar Possibility? [Centauri Dreams])

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:

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)

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:

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})

Take a look at Matloff's paper The Hoop Solar-Photon Sail and Extrasolar Travel (PDF) via Centauri Dreams via Atomic Rockets.

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 ")

Dust Movement On The Moon, Saturn's Rings Solved
'...The dust normally on the surface picks up and keeps a charge.' - Hal Clement, 1956.

Axiom - The World's First Private Space Station?
'So Webb Foster had built his space laboratory... It was a great crystal sphere, a thousand feet in diameter.' - Nat Schachner, 1937.

Moon's Huge Lava Tubes Perfect For Heinlein's Bat Wings
'It's just a big volcanic bubble, two miles across...' - Robert Heinlein, 1957.

Planet Buster Dead Star Vaporizes Mini-Planet
'A planet buster - thatís a Class-A oxygen bomb.' - Kendall Foster Crossen

 

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.

 

 

 

 

 

Current News

Cormorant Flying Car
'The cab came floating down out of the sky...'

ElliQ Robot To Help Israel's Grandmas And Grandpas
'The robant and the tiny old woman entered the control room slowly...'

EU Debates Kill Switches For Robots
'I have a mechanism which our autofac on Mars builds as an... emergency safety...'

Scotland Set To Implement Basic Income
'Earned by just being born.'

Sales Robots More Persistent Than Humans
'Robot-salesmen were everywhere, gesturing,,, shrilling...'

AI Identifies Suicidal Behavior With 93 Percent Accuracy
'...He padded into the living room, and seated himself by the suitcase; he opened it, clicked switches, and turned on Dr. Smile.'

Razer Project Valerie Laptop Unfurls
'A paper thin polycarbon screen unfurled silently...'

Can Virtual Reality help People Cope With Pain?
Research is promising.

Dust Movement On The Moon, Saturn's Rings Solved
'...The dust normally on the surface picks up and keeps a charge.'

Largest Micro-Drone Swarm Release Successful
'... Programmed to hang in space in a hexagonal grid pattern.'

Robot Motion Planning 10K Times Faster
'The robot crab... fired a burst of light, then froze...'

Reconfigured Graphene 10X Strong, 5 Percent Dense, As Steel
'...It was made of Alohydrolium, which is the lightest of all metals.'

Axiom - The World's First Private Space Station?
'So Webb Foster had built his space laboratory... It was a great crystal sphere, a thousand feet in diameter.'

DataTraveler Ultimate Generation 2 Terabyte Flashdrive
'A man or woman could carry AIs or complete planetary data spheres...'

HyperFace Aims To Foil Facial Recognition
'...A million and a half physiognomic fraction-representations of various people.'

MIT's aeroMorph Technology
'... It falls into that structure like a rubber figure returning to shape.'

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.