Over the last 2 centuries the energy that cutting-edge scientific research experiments require has increased at an almost exponential rate. (Give examples)
None of the methods of energy production currently in use or development can hope to produce even a fraction of the useful, and storable, mega-wattage that mankind could profitably use for research experiments and mega-engineering projects of the sort that you find in hard science fiction stories.
A new approach is required if we are to learn and build even a fraction of what we know we could… if we could only generate and store that much energy.
Linear Accelerators
Linear accelerators have been around for more than one hundred years. A basic LA is simply a perfectly straight line of rings on edge in a row with electro-magnets around the rim and a way to control the timing of the rings.
Imagine a 20 foot long tube sliced into hundreds of rings and stretched out to 60 feet. Each ring has dozens of electro-magnets with one pole pointed straight at the center of the ring. Each ring has circuits to control the timing of all of the magnets in each ring, as well as which pole is N and which S, so as to accelerate particles with the opposite charge of the inner poles. When a charged particle approaches the end of the tube it accelerates toward the ring. As the particle reaches the ring its magnets turn off, the next ring is switched on, and the particle continues to accelerate. This process is repeated all along the line of accelerating magnets, hence the name, linear Accelerator.
If a linear accelerator is bent into a perfect circle the charged particles circle around and around accelerating to the limit of the ability of the magnets to keep the particle from flying off in a straight line from sheer momentum.
The only hard limit on velocity is the speed of light and the only limit on the size of the particle accelerated is the power of the electro-magnets.
If You Can Throw, You Can Catch
A basic electric motor is also an electric generator. If you put current in it turns, if you turn it then out comes virtually the same amount of current.
Scientists have been accelerating particles since before the turn of the last century. In the mid-1900’s Robert Heinlein proposed using linear accelerators in the vacuum of space to launch spacecraft and before the millennium military weapons had been designed and tested that used vehicle mounted L. A.’s to fire projectiles at previously unheard-of velocities.
All of these approaches use the linear accelerator as a motor, adding velocity at the cost of electricity. This paper explores the possibility and practicality of using a linear accelerator as a generator by catching and decelerating metal lumps mined from asteroids and dropped in the outer solar system.
The only limit on the electricity produced by the Kinetic Linear Accelerator (K. L. udge) is the size and velocity of a “particle” entering the mouth of the linear accelerator.
The resulting electricity can either be used as it is generated locally, or anywhere in the system after being beamed via microwaves, or it can be fed into a storage system of sufficient capacity.
Since the output is only limited by the size and capacity of the linear accelerator the best location for the mining/drop operation is in deep space far from Earth. Nickel-iron is smelted into “slugs” that are dropped outside the orbit of Mars, reaching cometary speeds as pass into the accelerator/generator stationed inside the orbit of Mercury.
Prospecting In Space
In the asteroid belt and beyond there is more nickel iron than will ever be mined from the Earth’s crust. The economics and engineering of prospecting and smelting operations in deep space have been worked out in detail over the last 50 years by many prominent scientists and futurists: Forward, Dyson, Benford, and Heinlein to name a few.
Nickel-iron “particles” of arbitrary size can be created by collecting, refining and combining almost pure nickel-iron asteroids ranging in size from a few feet across to the size of small mountains.
Once a particle is assembled it can be decelerated into its descent spiral with any of a number of passive acceleration systems such as light sails or ion drives.
Cometary Toboggan Ride
Ensuring that the Earth can never be the accidental or purposeful target of “particles” massing anywhere from kilotons to teratons would be paramount.
Bodies in orbit can be dropped into a lower, faster orbit by slowing their speed along their orbital path. As the body is slowed it will spiral down with accelerating velocity due to the gravitational pull of the body being orbited. A body in a regular orbit between Mars and Jupiter that is slowed so much that it spirals down inside Mercury’s orbit will have a literally astronomical velocity, and momentum, when it reaches perihelion (closest approach to the Sun).
Safety demands only orbits that avoid the Earth and the “particles” should be constantly tracked and positive control maintained until such time as it is impossible to alter the orbit into a dangerous path.
The change in vector from the natural orbit starts out slowly regardless of the propulsion system used. A small change in vector will add up over time. The more time it has to develop the more the end-point of the orbit will change. The closer an object in orbit gets to its parent body the faster it travels. All of this adds up to it being harder to change an orbit to hit a particular point, let’s say Earth, the further it has fallen toward the Sun. A dangerously sized body that is suddenly decelerated near the orbit of Jupiter will be traveling so fast by the time that it passes the orbit of Mars that it would impossible to retarget toward the Earth, especially if the intended orbits are timed to make it as hard as possible to redirect them into dangerous paths that are too fast to be detected and corrected. A body hijacked before it reached a high velocity would take a correspondingly longer time to reach its target.
As long as their descending spirals are plotted with this in mind it is only necessary to track and control each body for a fairly small part of its journey to the orbit of Mercury.
Down the Rabbit Hole
The linear accelerator itself needs to be as significantly more massive than the nickel-iron entering it as possible to keep from being knocked out of position, or even melted, by the energy of momentum transferred to it when it converts that momentum of the falling mass directly into electricity.
At the same time the closer to the Sun the Kinetic Linear Generator (KLG, or Kluge) is located the more energy of momentum the falling body will possess.
Therefore the Kluge installation should be as close to the Sun as state-of-the-art engineering will allow. An unmanned Kluge could likely be maneuvered remotely into orbits that would be impossible for humans to survive.
Mercury Rising
The resulting electricity would need to be transmitted to where it can be immediately used, or stored. If the Kluge is in orbit close to Mercury a control station can be placed in the LaGrange point in Mercury’s shadow.
Batteries Required
Due to the huge volume of energy being generated in a relatively short period of time, as well as their expense and volatility, conventional batteries and fuel cells are not up to the task. Instead a large array of huge Leyden jars or other brute-force capacitors can take up the electricity and dole it out in large or small increments to where it can be used or converted into maser beams for transmission around the Solar System.
Bootstrap Building
The materials for the initial asteroid mining spacecraft would come from mines and refineries on the Moon. Unending and powerful Solar energy and the abundant Lunar minerals coupled with no atmospheric friction and only 1/6th of Earth’s gravity make the Moon the ONLY place for mankind’s first serious space-shipyard whether the goal is building robot probes, sending humans to Mars or building orbital habitats.
Once prospecting spacecraft are operating past the orbit of Mars the process of assembling the mega-teratons (exatons) needed for the Kluge can begin.
The Assembly of the Kluge should be staged as close to the Sun as it is safe for the work to be done to minimize the energy needed to move it into its final orbit. The ability of robots to operate in closer orbits where humans cannot must be balanced against the faster and more flexible capabilities of on-the-spot human astronauts.
Construction materials sent in a body down to the construction site would travel long, slow Hohmann orbits so that they can be easily placed into a stable orbit that does not wander very far from the Kluge while the energy-producing nickel-iron masses would be sent on short, fast hyperbolic orbits that could only be diverted by the Kluge.