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
 |
Powdered Regolith Propulsion
Wouldn't it be handy if you found a way to move your spacecraft using stuff that you found in space? Rather than needing to lift everything up from Earth's deep gravity well?
I remember in Arthur C. Clarke's 1955 scifi novel "Earthlight", he postulated that interplanetary rockets used ion drives, and the reaction mass was "finely divided dust"
— Winchell Chung⚛🚀 (@nyrath) July 1, 2020
This tweet references an earlier article from The Space Review on using powdered dust found on objects throughout the solar system.
Electrostatic propulsion is the method used by many deep space probes currently in operation such as the Dawn spacecraft presently wending its way towards the asteroid Ceres. For that probe and several others, xenon gas is ionized and then electrical potential is used to accelerate the ions until they exit the engine at exhaust velocities of 15–50 kilometers per second, much higher than for chemical rocket engines, at which point the exhaust is electrically neutralized. This method produces very low thrust and is not suitable for takeoff from planets or moons.However, in deep space and integrated over long periods of engine operation time, the gentle push of an ion engine can impart a very significant velocity change to a spacecraft, and do so extremely efficiently: for the Deep Space 1 spacecraft, the ion engine imparted 4.3 kilometers per second of velocity change (delta-v), using only 74 kilograms of propellant to do so. As of late September, Dawn’s ion thrusters have produced 10.2 kilometers per second of delta-v, using 367 kilograms of xenon...
Chemical rockets achieve their large thrust with high mass consumption rate (dm/dt) but low exhaust velocity; therefore, a large fraction of their total mass is fuel. Present day ion thrusters are characterized by high exhaust velocity, but low dm/dt; thus, they are inherently low thrust devices. However, their high exhaust velocity is poorly matched to typical mission requirements and therefore, wastes energy. A better match would be intermediate between the two forms of propulsion. This could be achieved by electrostatically accelerating solid powder grains.
Imagine a vehicle that is accelerated to escape velocity by a conventional rocket. It then uses some powder lifted from Earth for deep-space propulsion to make its way to a NEO, where it lands, collects a large amount of already-fractured regolith, and then takes off again. It is already known that larger NEOs such as Itokawa have extensive regolith blankets.
After leaving the NEO, onboard crushers and grinders convert small amounts of the regolith to very fine powder. (These processes would be perfected in low Earth orbit using regolith simulant long before the first asteroid mission.) Electrostatic grids accelerate and expel the powder at high exit velocities.
Science fiction writers have long speculated on the use of what Jack Williamson called positive ray propulsion in his 1931 classic The Prince of Space:
These mammoth vacuum tubes, operated at enormous voltages from vitalium batteries, were little different in principle from the "canal ray" apparatus of some centuries before. Their "positive rays," or streams of atoms which had lost one or more electrons, served to drive the sunship by reaction—by the well-known principle of the rocket motor.
As Winchell Chung of Project Rho points out, Arthur C. Clarke described a finely divided dust propellant, that is, powdered lunar regolith:
The liners that plied from world to world obtained all their propellant mass here, filling their great tanks with the finely divided dust which the ionic rockets would spit out in electrified jets. By obtaining that dust from the Moon and not having to lift it through the enormous gravity field of Earth, it had been possible to reduce the cost of space-travel more than ten-fold.
Be sure to read his page on torchships, which provides a comparison between ion-drive spacecraft which have spit out economical streams of propellant mass, and "honest-to-Heinlein torchships" which don't spare the horsepower.
Scroll down for more stories in the same category. (Story submitted 7/1/2020)
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 ")
SETI Suggests Prospecting The Solar System Without Landing
'From a distance it could resolve the cosmic rays reflected from various substances.' - Philip Nowlan w/D. Calkins, 1929.
Cislunar Space And The Space Lanes of Golden Age Science Fiction
'He had travelled the space-lanes of the solar system for the greater part of his life...' - Edmond Hamilton, 1928.
NASA Moonbase Update
'The dinner was excellent. It was completely vegetarian — grown in specially prepared gardens in this Moon base...' - Jim Vanny, 1931.
The Solar Oberth Slingshot
'And if it doesn’t work,' inquired Lazarus, 'what does that make us? Sunspots?' - Robert Heinlein, 1941.
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
Prairie Madness - And Space Sickness
'Space-sickness is one of the most unpleasant sensations that a human being can experience. Not all are subject to it...'
Can Stratospheric Aerosol Injection Control The Weather?
'...I saw a nice black heavy-looking cloud sailing by just now, and I can get the electrical machine out in five minutes to draw it down.'
SETI Suggests Prospecting The Solar System Without Landing
'From a distance it could resolve the cosmic rays reflected from various substances.'
Wolfram Alpha Mathematica Predicted by Science Fiction in 1948!
'The answer to the dumb student's prayer.'
Cislunar Space And The Space Lanes of Golden Age Science Fiction
'He had travelled the space-lanes of the solar system for the greater part of his life...'
NASA Moonbase Update
'The dinner was excellent. It was completely vegetarian — grown in specially prepared gardens in this Moon base...'
Neuralink Will Allow Humans To Communicate With ... Animals?
'Telepaths had their sensitiveness enlarged to an immense range by the pin-sets, which were telepathic amplifiers adapted to the mammal mind.'
Special Lights For Driverless Cars!
'That light is actually the Anamorphic Equalizer...'
'Old People Began to Cross The Continent In Their Own Cars'
'It was a relief to enter one of the comfortable autos, whisper a direction down the tube, and just know that you would be taken to your destination in the quickest, safest, and cheapest manner.'
Harrison Bergeron, Illustrated And Practiced
'But he didn't get very far with it before another noise in his ear radio scattered his thoughts. George winced...'
Starfall Manufacturing Drugs In Space
'The vast spinning sphere of Factory in the Sky loomed above and ahead of us, gleaming white against the unfathomable jet depths of surrounding space.'
The Solar Oberth Slingshot
'And if it doesn’t work,' inquired Lazarus, 'what does that make us? Sunspots?'
'Maybe The Woman Of Your Life Is Still Under Production'
'The Dillard people had performed a miracle and put all the works in a girl-modeled case.'
'If Anyone Is Watching Earth...'
'Our study of your race has convinced us that you are not fitted to leave your planet in the present state of your civilization.'
Epirus High-Power Microwave Defeats Drones
'...the spreading beam of the deranging ray struck them, and Then one toppled and fell. Then another.'
Cloud Of Space Rubbish From China's Long March Rocket
'Within seconds the material was spread out over fifty yards, in a matter of hours it might occupy several cubic miles of space...'
