Maybe it’s due to the political landscape and the upcoming US elections… maybe it’s because of an uncertainty in the future of our ecological state, or a concern that an unexpected meteor could end civilization as we know it… maybe it’s just because people want a fresh start… but it’s become an opportune time for scientists, SF fans and everyone else to discuss the possibilities of living in space.

A lot of people have envisioned living in orbiting satellites, either writing novels (like myself), commissioning studies on how to actually do it, or just creating cool artwork about them.  The idea is to live more lightly upon the land by putting the populations into a controlled environment off Earth, and incidentally, to give people a haven from environmental disasters.  A quick search on Space Habitats will turn up an incredible variety of studies and art, with many different styles of satellites imagined.  It’s interesting to compare them to the satellites I envisioned in Verdant Agenda and Verdant Pioneers, and note the similarities and differences.

When I first saw Spacehab’s Kalpana One Space Settlement (below left), I realized it had a lot of similarities to my conception of the city-satellites in my novels, most notably the very popular idea of rotating the main structure to simulate a standard Earth gravity on the interior, making sure residents would not suffer the debilitating effects of low- or no-gravity (0-gee) on the human body.

Kalpana One interiorSpacehab’s art also features a central column, running from pole to pole, providing light to the satellite interior.  I agree with Spacehab that this is a better idea than the other popular concept of opening mirrors to direct light through massive glass panes to the satellite’s interior: The Sun is simply too intense to give direct (even reflected) access to the interior of a satellite; between the raw energy and the radiation from the Sun’s glare, the interior would be an irradiated hell in no time.  Shielding the interior from direct sunlight makes much more sense, and the exterior can be fitted with solar cells to capture all that energy pretty efficiently.  And the light pole can be varied in intensity to simulate the natural day and night cycles of Earth, to which all Earth life is strongly accustomed.

A significant difference between Spacehab’s design and my concept is the overall length of the satellite: Whereas they envision a can shape, not much longer than it is in diameter, the satellites in the Verdant series are kilometers long, presenting a distinct cylindrical shape.  They are more similar in size and shape to the satellites envisioned by Gerard O’Neill’s concepts in The High Frontier.  The Verdant satellites are supposed to equal the land mass of a small country, or at least a megacity or two.  It would be large enough to require the use of public transportation to cover its significant distances from pole to pole.

satellite interiorThe bulk of living in a Verdant satellite takes place on the interior of the outer hull, the main floor.  To my satellites I added terraced structures at the north pole, a ring of levels designed to rotate independently of the main floor at certain rates to simulate 1-gee at the lower levels, a fraction of a gee at mid-levels (for those recovering from health issues where a lessened gravity would aid healing), and 0-gee close to the hub (for handling of heavy cargo, and for experimentation and manufacturing that would benefit from 0-gee).  Most of the satellite’s control and administrative offices are in this ring of buildings.

In order to maximize space for the populace, I assumed very few would have free-standing private homes, and instead would live in flats of various sizes in common buildings on the main floor.  Verdant features an abundance of natural areas, woods and parks, sports fields and lakes, a preponderance of green and open public areas that will encourage outdoor activities and take the edge off of living in a giant cylinder in space.  The trees and other greenery will also contribute to the cleaning of the atmosphere, scrubbing carbon dioxide and adding oxygen to the air, as well as providing natural fragrance and supporting some wildlife (including the insects and small critters that help maintain plant life by their activities).

Kalpana One Space Settlement exteriorA great deal of spaceship traffic would travel through the hub, taking advantage of 0-gee to move large ships and heavy cargo.  Due to the greater size and requisite population, however, the hub could not handle all of the ship traffic and cargo; so I devised a system of scaffolds around the outer hull, designed to move along the hull counter to the satellite’s rotation on tracks, allowing them to capture ships at 0-gee; then the scaffolds would slow on their tracks to match the satellite’s rotation, bringing the ships up to the same 1-gee of the interior, and transfer the ships into docking bays in sub-floors along the outer hull.  Being docked at 1-gee would make it easier for passengers to debark and board at normal gravity, and more maneuverable cargo could be loaded by hand.  And when ships were ready to depart, they could be taken outside just as they were taken in, or could simply “drop” out of the bay, using the boost from centrifugal force to start them on the way home.

I envisioned Verdant and its sister satellites to be fully independent territories, filled with administrators, residents and businesspeople, trading with businesses on Earth for the essentials and incidentals required for a comfortable life.  Verdant was designed to feel as real as possible, so the events in the story would have a real impact for the reader.  The detail I put into Verdant Agenda and Verdant Pioneers provided that realism.