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
 |
New ESAIL Video: Deploy Tethers!
An ESAIL may start out slowly, but it could turn out to be the fastest man-made vehicle ever constructed. The European Union is funding a three-year project to build an ESAIL craft.
The following video shows the basic deployment strategy and propulsion of the ESAIL.
A full-scale electric sail consists of a number (50-100) of long (e.g., 20 km), thin (e.g., 25 microns) conducting tethers (wires). The spacecraft contains a solar-powered electron gun (typical power a few hundred watts) which is used to keep the spacecraft and the wires in a high (typically 20 kV) positive potential. The electric field of the wires extends a few tens of metres into the surrounding solar wind plasma. Therefore the solar wind ions "see" the wires as rather thick, about 100 m wide obstacles. A technical concept exists for deploying (opening) the wires in a relatively simple way and guiding or "flying" the resulting spacecraft electrically.The solar wind dynamic pressure varies but is on average about 2 nPa at Earth distance from the Sun. This is about 5000 times weaker than the solar radiation pressure. Due to the very large effective area and very low weight per unit length of a thin metal wire, the electric sail is still efficient, however. A 20-km long electric sail wire weighs only a few hundred grams and fits in a small reel, but when opened in space and connected to the spacecraft's electron gun, it can produce several square kilometre effective solar wind sail area which is capable of extracting about 10 millinewton force from the solar wind. For example, by equipping a 1000 kg spacecraft with 100 such wires, one may produce acceleration of about 1 mm/s^2. After acting for one year, this acceleration would produce a significant final speed of 30 km/s. Smaller payloads could be moved quite fast in space using the electric sail, a Pluto flyby could occur in less than five years, for example. Alternatively, one might choose to move medium size payloads at ordinary 5-10 km/s speed, but with lowered propulsion costs because the mass that has to launched from Earth is small in the electric sail.
(ESAIL illustration)
Science fiction fans may be reminded of the magships from Falling Stars, the 1998 novel by Michael Flynn, which use a magsail:
"How fast will this thing go?" the rigger wondered."Depends on current density, orientation, and a bunch of other factors programmed into the RAM pins here." He flourished the goat-case, careful not to shake it. "If you're sailing large before the wind, your acceleration is about a thousandth of a gee."
"That don' sound so fast, friend."
Jimmy grinned, having said almost the same thing to Hobie last year. "Not compared to an SSTO main engine, right. Get a couple of gees squashing your bag during a lift, right? The sail gives a gentler push, but it keeps on pushing. You don't run out of fuel unless the sun goes out; in which case fuel is not your major concern. Bottom line is: a magsail can get you to Mars in about the same time it took the Mayflower to cross the Atlantic."
Via Electric Solar Wind Sail (E-sail); thanks to Jim Bowling for the tip and the reference.
Scroll down for more stories in the same category. (Story submitted 12/12/2010)
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 ( 1 )
Related News Stories - (" Space Tech ")
Beautiful Visualization of Dawn Spacecraft
'Then he became aware of a gentle pressure pushing him away from the ship.' - Isaac Asimov, 1939.
Tumblin' Tumbleweed Rovers To Eplore Mars
'His sensors out and working, and the whirring of the tape that sucked up sight and sound and shape and smell and form...' - Clifford Simak,
Tentacled Robot Captures Space Debris
Preventing annoying space debris build-up.
Reflect Orbital Sunlight On Demand
'I don't have to tell you about the seven two-mile-diameter orbital mirrors that circulate around the satellite, making it habitable.'
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
You Will Eat The Cookies Made From Plastic...
'Our planes are going to start bringing in bales of discarded plastics...'
It's A Giant Robot! You Reporters Have Been Warned!
'... completely forgetting the ship at sight of the awesome figure and great head of the giant Gaut...'
Birds Learn To Sing Pictures ala Frank Herbert's Distrans
'We will fight in the time of fighting.'
ElectionSim: China's 'Ender's Game' Battle Sim, Or Lem's 'Kingdom In A Box'?
'So, Ender, we will now begin your education.'
Tactile Skin Supplier Map
'What strange sensitivity! What an amazing development of science was manifested in every move and act and word of this Robot!'
Flock Stymied By 'Adversarial Fashion'
'Forget the head atop it, the legs below, feet, arms, hands. It compels erasure.'
Orb Nomad Zero-Emission Electric Aircraft
'That explains how it was so easy for me to remain motionless in midair or to perch on a flagpole in imitation of a giant bird, even in the windy city of Chicago.'
ICE Buys Shock Gloves Like Batman's
What else is the Caped Crusader using?
Factories In The Sky Will Surpass Those Of Earth
'The thirty-odd miles of The Factory’s circumference...'
Sleeper Drones Lie in Wait
'Wandering mines, you took them out on the edge of the desert, set them down and activated them.'
Warfare Goes Underground In Ukraine
'Once in the very first weeks of the war, before everyone had been evacuated from the surface...'
Robot Bees 3D Printed By Festo
'At first I was struck by the large size of these bees..'
3D Printed Organs From Space
'For a while your colonists will have to come up to the [orbital] Hospital...'
DIY Robot Scorpion Crushes It
'...it raised its front end off the ground and waved its antennae at them, then raised one armoured claw as if to snip them out of the sky.'
How To Settle An Argument Between Two Robots
'Henry... assumed the curious absent look of a robot talking on the TBR circuits.'
The Wind Phone Calls Those Who Have Passed On
'Only I heard that!'
