SPACE CITIES
FUTURE
POSSIBILITY?
FUTURE
POSSIBILITY?
SPACE CITY RINGS
Space City Rings are held aloft at altitudes of about
150 KM by ground based rings of about 200 km in
diameter. These rings are constructed from
superconducting cables.
Space City Rings are held aloft at altitudes of about
150 KM by ground based rings of about 200 km in
diameter. These rings are constructed from
superconducting cables.
INTRODUCTION
Magnetic forces have been invoked for maglev levitation of trains and for launching space vehicles. In each case,
the magnetic forces between the moving object and a rail are exerted over a very short distance. Magnetic forces
between two current loops fall off with the fourth power of the distance between the coils. Thus, it has been
considered out of the question to directly push a vehicle into space without solid rails, or launching along tracked
rails or tubes.
The fall off with distance to the fourth power only applies when the current loops are separated by a large distance.
When the current loops are within one loop radius of each other, the forces are considerable. The space cities
concept involves making a ground based current loop with about a 200 KM radius, with extremely high electrical
currents and a second 200 KM current loop that is lifted to an altitude of about 150 KM.
The first figure above illustrates two such current loops. The current loop on the earth's surface (green) is the
base loop. The levitated current loop is depicted in yellow, and it is at an altitude of about 150 KM. The electric
current in the levitated loop is supplied by microwave power beaming from an earth based antenna. The
microwaves are converted to electrical DC current by rectennas located on the levitated loop. The forces involved
in this system can be 100's of millions of pounds, allowing a complex space city to be built on the levitated loop.
This levitated loop could be a space port that is a transit station into space. The space lift vehicles
Magnetic forces have been invoked for maglev levitation of trains and for launching space vehicles. In each case,
the magnetic forces between the moving object and a rail are exerted over a very short distance. Magnetic forces
between two current loops fall off with the fourth power of the distance between the coils. Thus, it has been
considered out of the question to directly push a vehicle into space without solid rails, or launching along tracked
rails or tubes.
The fall off with distance to the fourth power only applies when the current loops are separated by a large distance.
When the current loops are within one loop radius of each other, the forces are considerable. The space cities
concept involves making a ground based current loop with about a 200 KM radius, with extremely high electrical
currents and a second 200 KM current loop that is lifted to an altitude of about 150 KM.
The first figure above illustrates two such current loops. The current loop on the earth's surface (green) is the
base loop. The levitated current loop is depicted in yellow, and it is at an altitude of about 150 KM. The electric
current in the levitated loop is supplied by microwave power beaming from an earth based antenna. The
microwaves are converted to electrical DC current by rectennas located on the levitated loop. The forces involved
in this system can be 100's of millions of pounds, allowing a complex space city to be built on the levitated loop.
This levitated loop could be a space port that is a transit station into space. The space lift vehicles
TECHNICAL PROBLEMS-STABILITY FROM FLIP
We have not solved the stability problem. We have ideas but they have not been adequately studied. If you take
two permanent circular magnets and hold them one above the other, you quickly see that they are prone to "flip"
over and be forced together. One potential means of avoiding this is to have the levitated loop rotate and stabilize
much like a gyroscope. Jets could be attached and the stability could be maintained much as the space station.,
The concept of the space city is presented here because much of the technology for the idea exists. The magnets
can be built as shown below. Microwave power beaming is possible and can be engineered. This is an idea that
could make Space travel accessible to everyone, not just highly trained astronauts.
We welcome the interest of individuals or institutions that might be able to
contribute to the stability issues.
We have not solved the stability problem. We have ideas but they have not been adequately studied. If you take
two permanent circular magnets and hold them one above the other, you quickly see that they are prone to "flip"
over and be forced together. One potential means of avoiding this is to have the levitated loop rotate and stabilize
much like a gyroscope. Jets could be attached and the stability could be maintained much as the space station.,
The concept of the space city is presented here because much of the technology for the idea exists. The magnets
can be built as shown below. Microwave power beaming is possible and can be engineered. This is an idea that
could make Space travel accessible to everyone, not just highly trained astronauts.
We welcome the interest of individuals or institutions that might be able to
contribute to the stability issues.
WHAT DOES WORK
The large superconducting current loops can be constructed with existing technology. Engineering
design of a superconducting current installation that includes all the necessary features and is
already about 1KM in diameter were developed for energy storage of peaking electrical current in
an Electric Power Research Institute study entitled,"Conceptual Design and Cost of a
Superconducting Magnetic Energy Storage Plant", EPRI-EM-3457, April, 1984. The design was not
put into practice because of concerns over magnetic fields in the air and surroundings of the
current coil. (This would of course be a problem with its use to form a space city, but the benefits
would be enough to make it imperative to find a suitable location.)
Microwave power beaming, to supply the electrical current to the levitated coil is also a technology
that is relatively well developed.
The large superconducting current loops can be constructed with existing technology. Engineering
design of a superconducting current installation that includes all the necessary features and is
already about 1KM in diameter were developed for energy storage of peaking electrical current in
an Electric Power Research Institute study entitled,"Conceptual Design and Cost of a
Superconducting Magnetic Energy Storage Plant", EPRI-EM-3457, April, 1984. The design was not
put into practice because of concerns over magnetic fields in the air and surroundings of the
current coil. (This would of course be a problem with its use to form a space city, but the benefits
would be enough to make it imperative to find a suitable location.)
Microwave power beaming, to supply the electrical current to the levitated coil is also a technology
that is relatively well developed.
MAGNETIC ENERGY STORAGE CURRENT LOOPS
Detailed engineering studies were performed by General Atomic Corporation for EPRI (The Electric Power
Research Institute. The conceptual study cited above includes the following figures. There were to be 112
coils, each carrying 765,000 amperes of current in superconductors. The diameter of this coil was to be 784
meters. This is about 1/250 th of that needed for a space city.
Detailed engineering studies were performed by General Atomic Corporation for EPRI (The Electric Power
Research Institute. The conceptual study cited above includes the following figures. There were to be 112
coils, each carrying 765,000 amperes of current in superconductors. The diameter of this coil was to be 784
meters. This is about 1/250 th of that needed for a space city.
SAFETY AND REDUNDANCY ISSUES
Numerous safety issues and issues of practicality will need to be addressed.
1. Potential impact on the ozone layer
2. Meteorites, UV and Solar Radiation. (Like the space station, this city would be
exposed to all of these issues.
3. Oxygen and Material supplies. (These would be brought to the station on
heavy lift vehicles.
4. The magnetic field loops will need to be maintainable and serviceable. That
means there would need to be redundancy in current loops.
Numerous safety issues and issues of practicality will need to be addressed.
1. Potential impact on the ozone layer
2. Meteorites, UV and Solar Radiation. (Like the space station, this city would be
exposed to all of these issues.
3. Oxygen and Material supplies. (These would be brought to the station on
heavy lift vehicles.
4. The magnetic field loops will need to be maintainable and serviceable. That
means there would need to be redundancy in current loops.