Spring Worlds -
Using Springs for Planetary, Luna and other Orbital colonisation.

by
Michael Bond, copyright, 2007

[Keys: Spring World, Springship, Mars Colony, Luna Colony, Space Colonisation, Space Station Design, Spinning Ring, EarthSpring, MoonSpring, MarsSpring]

Springships

In one of my earlier articles on the subject of deep spacecraft designs I introduced my own proposals and the new concept of "springships".

A springship utilises spinning rings (hence "springs") to provide a ship's crew with gravity and a safer living environment.  The same theme of springs will also be adopted for building this, ring, or other rotating vessels for static stations and colonies.

Now I want to introduce you to the most dramatic expression of such springs - the Spring World.

Spring Worlds ("Springs")

Whereas a Springship has at least a pair of small rings rotating within the Spring World is intended to deal with a more critical issue of space colonisation, and solve one of the core problems of colonising other worlds - how to keep space colonists healthy on a low gravity world, such as a Luna colony or a Mars colony.

Don't do it.

Instead of colonising a low gravity world I propose to construct very large springs as the principal habitat for millions, upto hundreds of millions of people.

The reason is that any colony established on a low gravity world, such as Luna or Mars colonies, will face the inevitable and irreversible (with current technology) problem of adapting to that world.  colonists born and raised on the moon or Mars, or any comparable environment, will never have experience of earth's own gravity and live.  They will not be able to return to Earth, and that's a one-way trip and potential deathtrap for such a colony.

While some advocates of colonisation enthuse endlessly about the wonders of colonisation there has to be a better way to guarantee that humans in the future do not find themselves trapped in environmental niches around the universe from which they cannot escape.

A Spring World offers this and another unique benefit - we don't have to despoil new worlds the way we have done with Earth.

Paradise Worlds

Spring Worlds allow us the opportunity to use new worlds in new ways.  Turn Mars and even the moon into paradise parkscapes, great open ranches, farms and fields, wildernesses which everyone can enjoy, gardens of eden, and leave the bulk of our civilisation orbiting far overhead, out of the way.

No more messy suburbs or other urban complexes ripping up a world's surface, except for a few to handle regular traffic, tourists, school parties, farmers and those on walkabout, the world's surface is clean and untouched by concrete, fences, borders, barriers and more.

The Spring World provides for all industry, commerce, accommodation, etc.

The Spring World is the largest possible construct.  Beginning with a location as small as the moon, a Spring World is constructed as a single ring wrapped in close orbit around the planet, planetoid or moon.

This ring rotates both on its orbit and slightly faster than its required orbital speed to provide a permanent gravity for all inhabitants through centrifugal forces.

Scale - A Luna Spring
(The MoonSpring)

A Spring World can be of any size and the more advanced our technology the greater that size will become.

Even today our current technology already shows the first potential for building Spring Worlds.

If we look up at the moon we see a relatively small orbital body, only a couple of thousand miles in diameter (2,179 miles).  This is a circumference of 6,790 miles.

With no substantial atmosphere to pose any form of aerodynamic drag a Luna Spring World (MoonSpring) could be established relatively close to the moon's surface, say a couple of hundred, or less, miles up.  If we keep it simple the circumference would be about seven thousand miles.

Too big?  Really?

Calculations are already available to suggest that space lifts from Earth to a geostationary orbit (22,240 miles) will soon be practical with existing technology or that to arise in the very near future.  Carbon filaments show the potential to support the megatons of mass needed to hold a space lift to and from Earth. A cable used as a suspension support for the MoonSpring will be less than a third the distance.

Such cable distances are already in common use - trans-ocean telephone cables - so we know for certain that our world has the manufacturing capacity today to spin and lay very long cables.  This is the beginning of a smaller, practical Spring World.

Construction

To construct a Spring World you would begin with the placement of a series of key assembly and support stations in a desired orbit.  A small Luna orbit of seven thousand miles may only need a couple of hundred construction site bases.

From these you will span the gaps with the anchor cables, just like weaving the cables of a suspension bridge, to join the stations together, permit easy cable power transfer, movement between the stations, communications, etc.

As you assemble more resources you will increase the size and complexity of the bridges between the stations, first with a couple (at least two or three for redundancy) of foundation tubes, comparable to lightweight pipelines commonly used today for oil and gas supplies around the world.

The pipes are lightweight, but offer a more secure anchorage for the stations and the second generation anchor cables, weaving them in and wrapping around the tubes, between them and beyond, to create an ever increasing web of structural strength for something that must remain safe and solid for centuries (no built-in obsolescence allowed up there).

Following the laying of the foundations the first habitat structures can begin to grow from the anchor stations. pushing larger bore corridors and internal facilities out from the stations in a manner similar to the way deep bore road and railway tunnels are built on Earth today, pushing a ring of segments out yard by yard, mile by mile.

The first spring cores may only be a few tens of feet in diameter, acting as the second generation foundations and the first generation accommodation.

The third and subsequent generations build on these techniques and enlarge the scale of the Spring core from tens of feet to hundreds of feet in diameter.

Spinning The World Ring

I've written here about construction, but there is one more key feature required for a Spring World to become fully active - it must spin faster than a station in its orbit.

A faster spin creates a centrifugal force that simulates the force of Earth's gravity as people, objects, etc., are forced outwards by the spin, while the whole structure is anchored in position by the strength of the cables and the rest of the structure - interlinked and mutually supportive structures for redundancy.

From the occupant's point of view the world they are spinning around is now above them, permanently in the "sky" directly overhead, while space beyond is below their feet.

Capacity to Build Spring Worlds

In terms of manufacturing capacity none of this is impossible for Earth's current output.  We can already create huge cables and tunnel walls, the only issue will be the technology needed to lift it all into space, and that comes from using local resources or those found free floating in space - material from the moon or from free asteroids manoeuvred into a suitable position for use.

The current rate of technological advancement suggests an increasing capacity for unit production and more efficient forms of lifting, whether through magnetic accelerators on Earth and the moon or through breakthroughs in physics leading to new forms of lifting, possibly including gravity nullification.

Certainly the first Spring World (around the moon?) will be the most difficult, as were the first pyramids, but the prospect for the future shows that we already have the core skills and only lack the will to action.

That, I am certain, will come soon enough.

A Luna Colony of 600 Million?

A Spring World will not be small, its potential is too good to ignore, and I can easily imagine a capacity for accommodation upto a hundred thousand permanent residents for each mile, with a bore diameter of at least a couple of thousand feet.  Such a Spring colony will hold about six hundred million people.

Multi-Spring Worlds

Remember, each Spring World occupies one orbit around a world.  There is no rule against placing another Spring in a higher or lower orbit, and more beyond those.

Can you imagine a world in the far future with a series of rings like those of Saturn, glowing with their own life and colours, beacons of humanity glowing protectively over green terraformed paradise worlds below?

FOOTNOTE: It was only after writing this article that I recalled the author Larry Niven's "Ringworld" novel series.  While a Springworld is similar it is intended to be a practical use of current 21st century technology on a modest scale rather than a far-future elaboration of science fiction super-science.  It's likely I was influenced subconsciously by Larry's work, but I did not intentionally set out to mimic his work.