Atomic Rockets


A space station is basically a spacecraft with no propulsion. Which boils down to just the habitat module and the payload.

Much like spacecraft, in a science fiction story a space station can become a character all by themselves. Examples include Babylon 5, Deep Space 9, Waystar from Andre Norton's Uncharted Stars, Supra-New York from Heinlein's Farmer in the Sky The Green Hills of Earth and Rocket Jockey, Nowhere Near from Jack Williamson's short story with the same name, Venus Equilateral from the series by George O. Smith, Thunderbird 5 from the Thunderbird TV show, Elysium from the movie of the same name. For an exhaustive list, look up Islands in the Sky: The Space Station Theme in Science Fiction Literature and The Other Side of the Sky: An Annotated Bibliography of Space Stations in Science Fiction, both by Gary Westfahl. The latter has 975 examples.

There are some science fiction stories about star systems that have no colonists living on the surface of planets. All colonists live in swarms of space station habitats. Examples include Downbelow Station by C. J. Cherryl, The Outcasts of Heaven's Belt by Joan Vinge, and the system of Glisten from the Traveller role playing game.

Oh, Werner von Braun had it all figured out in 1952. In six issues of Collier's magazine he laid out a plan to send men to Luna and Mars. First you build a space ferry as a surface to orbit cargo transport (which was the great-grandfather of the Space Shuttle). Then you use it to make a space station.

And it was going to be a beauty of a space station, too. Three decks, 250 feet in diameter, and a crew of fifty. Makes the ISS look like a tin can. This outpost in space was where the Lunar expedition fleet would be constructed.

It would pay for itself as well. Meteorologists could plot the path of storms and predict the weather with unprecedented accuracy. Radio and TV signals could be transmitted all over the globe. Not to mention observing the military activities of hostile nations.

In other words, it would be MacGuffinite.

Why was this marvel never constructed? Because some clown invented the printed circuit. Freed from the tyranny of fragile and short-lived vacuum tubes, technologists could make unmanned satellites for Meteorologists, radio and TV signals, and watching hostile militaries. Such satellites could be assembled and launched at a fraction the cost of a manned station. They also did not require constant resupply missions to keep the crew alive.

If we had followed von Braun's plan, we would have ended up with a fleet of space ferries, a titanic manned space station, a large lunar base, and men on Mars. Instead, we have four overly complicated space shuttles near the end of their operational life that have been retired, a four man space station due to be de-orbited and destroyed in 2016, and a few bits of space trash on the Lunar surface. And we haven't been back to Luna since 1972. So it goes.

Why doesn't a space station fall down? A station is in "orbit," which is a clever way to constantly fall but never hit the ground. The ground curves away just enough so that the station never strikes it.

Actually, the International Space Station is in a low enough orbit that atmospheric drag decays its orbit. Periodically, Russian resupply rockets have to boost it higher. Otherwise it would de-orbit and burn up in re-entry. Many readers of this website are too young to remember when NASA's Skylab unexpectedly fell.

Many station designs are wheel shaped, and large wheels at that. They are wheel shaped so you can spin them for artificial gravity. They are large wheels so the rotation rate can be kept low enough so the crew does not experience nausea. This is conservatively 3 RPM, though studies suggest some can acclimate themselves to tolerate up to 10 RPM. The Collier space wheel is 250 feet in diameter and spins at 3 RPM, providing about one-third gee of artificial gravity at the rim.

Station Station Problems

Air Is Not Free

Habitable planets are great! Inhabitants have quaint expressions such as "Free as Air!"

In space, there ain't no free breathing mix. Any breathable air you either brought along or are manufacturing out of local resources. Neither of which is free, or even inexpensive. Air costs money. If you want to breath, you have to pay.

With interplanetary tourists, the "air tax" is included in the fee for their tour package. People living in a space station have to pay their periodic air tax or suffer the consequences. This is why a space habitat is a particularly pure example of a hydralic state. Obey the people who control life support, or you'll find yourself suddenly trying to learn how to breath vacuum.

"Yes, the wording is such that the boycott will affect all space commerce activities carried on by the Commonwealth and its registered space facilities," Trip Sinclair observed, "even the League of Free Traders, Kevin."

"How about our Lagrangian operations?" Ursila Peri's video image wanted to know. "How can they boycott trade operations off-planet?"

"Is your air bill current, Ursila?" Trip asked her.

"Yes, but even if it wasn't, nobody out here would cut off another person's life support. If the credit line got over-extended too much for too long, we'd put the debtor on a ship home. We work together because there's a lot of nothing waiting for everybody beyond the bulkhead," she said. "They're going to have trouble enforcing tariff arrangements and trade boycotts out here, that agreement sounds exactly like something written up by a bunch of people who always have pressure around them and gravity to keep their feet on the floor. Earthworms!" She made it sound like an insult.

"Sandy, this is Jeri Hospah. Don't let his attempts at humor put you off; sometimes he means what he says. Jeri, find a sack for Sandy and issue him some chits. Then fake up some paperwork that will keep the Ell-Five people happy," Ali instructed us...

...Uncountable hours later, I awoke in the wan sleeping light of the personal compartment and was momentarily confused until I remembered where I was. I felt physically refreshed but still mentally fatigued. That's a dangerous condition in space because little things can kill a careless person.

Somebody had left a flight suit and a Remain-Over-Night kit. Jeri Hospah was either thoughtful or had a well-trained station crew. I took a sponge bath, put on the flight suit and slippers, and decided I might live if I could find breakfast.

The RON kit had a pack of chits—air, meal, water, airlock cycles—as well as an L-5 facilities directory and a visitor's card for the Free Traders' Lounge.

A note was in the kit. "Call me at 96-69-54 and I'll chit you breakfast—Jeri."

From MANNA by Lee Correy (G. Harry Stine) (1983)

(ed note: the superintendent explains the facts of life to the new voluntary exiles to Mars. Keep in mind that on Mars, the air you breath is NOT free, it has to be manufactured and you have to pay for it.)

"Hear and believe," Farr said. "Okay, chums, let me give you the facts of life. Number one. Don't try to escape. There's no place to go. If you make it outside, you'll live about fifteen seconds. There's no air out there, and your blood will boil away in your veins. It's not a pretty way to go, and I'm told it's painful as hell.

"Number two. Don't try to escape. You may think you're smart and see a way to get a p-suit. You may even be able to operate it. And then what? You can't make air, and you can't carry enough to get anywhere worth going. Running out of air's not a lot better than going out without a suit.

"Number three. Don't try to escape. Sure there's a town here, and sure there are a lot of people in it. But you'll pay for everything, and I do mean everything."

He lifted an orange disk that hung from a chain around his neck. I'd noticed that everyone except us newcomers wore one, but they weren't all the same color. "Air-tax receipt," Farr said. "Mine's orange because I'm due to have it recharged. If it turns red, that's it. Pay up or go outside. You'll need air medals, because God help you if anybody catches you in town without one."

"Why? What happens?" someone demanded.

"Outside," Farr said. "Not even a chance to pay up. Just out."

"And who's to put me out?" Kelso demanded.

Farr grinned. "Every man jack who's paid his taxes, that's who. Might take several for you, but they'll do it."

At Central Processing they charged our air tags to bright green, forty days' worth. They gave us a hundred Mars dollars, worth about half that in Federation credits. We changed our coveralls for new ones, with a choice of blue or orange.

I found a tunnel end to sleep in. They'd been digging out to expand the city, but this project was halted for lack of a labor force. Nobody bothered me. I figured I had nothing worth stealing, anyway. That turned out to be stupid: I had a charged air tag, and that would be worth my life if there was anybody around desperate enough to cut my throat for it. Nobody was, just then.

I'd been there ten days and my air tag was turning from green to yellow, It was getting time to move on. I figured another couple of days would do it.

From Birth of Fire (collected in Fires of Freedom) by Jerry Pournelle (1976)


"Lurker" is a homeless destitute person living on a space station, especially a space habitat. The person figures there are opportunities on the habitat, they spend most of their money traveling to it, when they can find no jobs the money runs out, so they have no money for a space flight ticket to somewhere else. They then move to anyplace they can find in the station, much like terrestrial homeless live under bridges. The space habitat administrators cannot afford to ship the lurkers elsewhere (there are so many of them), so the problem grows. Of course the lurkers are also preyed upon by the criminal underworld.

The term was invented by J. Michael Straczynski for his TV series Babylon 5, more accurately he adapted the term. In internet forums "lurkers" are people who read the forums but do not make posts or otherwise draw attention to themselves. Straczynski noticed this phenomenon when he was discussion the proposed TV show on GEnie, Compuserve, and Usenet back in the early 1990's. He thought the invisible forum lurkers were a good metaphor for the invisible homeless people on the Babylon 5 space station.

Three Generation Rule

Not generally recognized is the matter of Ken Burnside's Three-Generation Rule for space habitats (space stations where people live and raise new generations of children). As Rick Robinson puts it:

Ken can make authoritative correction of this, but the premise of the 3-gen rule is that the degree of social discipline needed for a space habitat to survive indefinitely is beyond the capability of "normal" human societies. The human tendency to favor short-term expediency will, over time, make the habitat ecosystem more and more precarious.

Putting it loosely, people tend to put off patching the leak in the roof till its raining.

In the Ten Worlds setting, this means that space habs tend to run down, and fail catastrophically in 1-5 generations from when they were established. The average is 3 generations, hence 3-gen rule. The one society in the 10W setting that has beaten this rule is the Library of Man, by adopting a social system that makes it seem very strange and almost "inhuman" to others.

Proviso: This applies only to habs that are socially independent, i.e., the major decisions are made locally, thus subject to local political expediency, etc. It does not apply to bases and such that are ultimately under some outside authority — the outside authority can order the leaks fixed, even if it means everyone has to work double shifts.

Rick Robinson

4) Political priorities - life path problems. Kinda getting back to the idea that each colony will need to come up with their own character, colonies would start with an archetype (not sure how to do this, but it'd be a function of looking at the initial reason for building the colony, money input and world climate/world traits) and then within that framework have random events that could happen based on planet and who colonized it. This would generate a set of planetary traits, such as idealism, pragmatism, greed, environmentalism et al that would effect the options available to the government when problems turned up. For example, a Three Generations Rule problem might be very easy for a highly pragmatic colony to deal with, while one that was high in idealism might run into problems. Yes, in a sense this is trying to ascribe in a half dozen variables a political/social culture...maybe impossible.

In John Varley's Gaea Trilogy, there are some corporations that wait for the 3-gen rule to kill a habitat. Then they swoop in, take possession, vent it to vacuum to sterilize it, and then sell it to some other idealistic group as a unique fixer-upper opportunity.

They built the Coven there. It was a cylinder seven kilometers long with a radius of two kilometers. Artificial gravity was provided by spin; night, by closing the windows.

But the days of isolation were over almost before they began. The Coven was one of the first nongovernmental groups to move into space in a big way, but they were not the last. Soon the techniques of space colonization were refined, cheapened, standardized. Construction companies began to turn them out the way Henry Ford had turned out Model T’s. They ranged in size from the merely gigantic to the Brobdingnagian.

The neighborhood began to look like Levittown, and the neighbors were odd. Just about any sizable lunatic fringe, band of separatists, or shouting society could now afford to homestead in the LaGrangians. L2 became known as Sargasso Point to the pilots who carefully avoided it; those who had to travel through it called it the Pinball Machine, and they didn’t smile.

Some of the groups couldn’t be bothered with the care and feeding of complex machinery. They expected to exist in pure pastoral squalor inside what was really just a big hollow coffee can. The developers were often happy to accommodate them, reasoning that all that expensive hardware, if installed, would only be abused. Every few years one of these colonies would come apart and fling itself and its inhabitants across the sky. More often, something would go wrong with the ecology and people would starve or suffocate. There was always someone willing to take one of the resulting hulks, sterilize it with free vacuum, and move in at a bargain price. The Earth never ran short of the alienated and the dissatisfied. The United Nations was happy to get rid of them and did not ask too many questions. It was a time of speculation-of instant fortunes and shoddy practices. Deals were made that would have shocked a Florida real estate developer.

From Wizard by John Varley

Technological Decline

A more long-term problem is that of Technological Decline. As Joan Vinge pointed out in THE OUTCASTS OF HEAVEN'S BELT: If a planetary colony falls into barbarism, everybody reverts to a non-technological agrarian society.

If an asteroid civilization falls into barbarism, everybody dies.

It takes lots of technology to run the oxygen system, airlocks, spaceships, hydroponics, nuclear reactors, and other items vital for life in space. No technology, no life. In other words, they are a Hydraulic state.

Betha saw suddenly the fatal flaw the original colonizers, already Belters, must never have considered. Without a world to hold an atmosphere, air and water -- all the fundamentals of life -- had to be processed or manufactured or they didn't exist. And without a technology capable of processing and manufacturing, in a system without an Earthlike world to retreat to, any Dark Age would mean extinction.


Station Functions

In his incredibly useful sourcebook for designing science fiction universes Star Hero, James Cambias lists some common uses for space stations:

Food-producing station
Forward base to support spacecraft. Sometimes called "staging base" if military. Generally located in a "remote" location, remote being defined as "a long distance from the home base of the supported spacecraft." (e.g., a military base can be "remote" even if it is near a huge metropolitan planet belonging to a hostile nation).
Orbital Shipyard. Closely related is Spacedock, an outer space version of drydock where spacecraft are repaired or refitted.
Space Superiority Platform
Armed military station keeping an eye on the planet it is orbiting. If a planet is balkanized, the station will watch military ground units belonging to hostile nations. If the planet is a conquered one, or the government is oppressing the inhabitants, the station will try to maintain government control and deal with revolts. In any case, read about planetary attack
Planetary Defense
Armed military station defending its planet from outside attack, orbital fortress. Note that an orbital fortress will be more heavily armed than a warship of the same mass since the fortress design can allocate the mass budget for propulsion in favor of more weapons. These will be in a close orbit to the planet they are defending.
Orbital propellant depot. Fuel refining and storage facility
Residential colony
Orbital factory or smelting plant. They can be near asteroid clusters with rich mineral deposits, or be for industries that would otherwise pollute an inhabitable planet.
Weather-monitoring station
Station monitoring the planet below. News media, military spy satellite, tracking global ocean and air traffic, remote listening post, etc.
Large solar power satellite, beaming energy to clients via microwaves
Medical isolation station, research into technologies too dangerous to experiment with on an inhabited planet (medical disease research, nanotechnology, biowarfare agents, etc.), customs quarantine stations for infected incoming passengers.
Scientific research. This can be for research that requires microgravity, or the station can be located near an interesting planet or astronomical phenomenon.
Orbital spaceport. There are more details about spaceports here

To which I would add:

Aldrin Cyclers
Cyclers are special stations in Hohmann orbits between pairs of planets. They are used as very cheap but very slow methods of interplanetary transport.
Boom towns
A "gold" strike in an asteroid belt or the establishment of a military base in a remote location may create a "boom town". The sudden appearance of large numbers of asteroid miners or enlisted people is an economic opportunity to sell them whiskey, adult entertainment, and other hard to find luxuries at inflated prices. Not to mention supplies and tools. Remember, in the California Gold Rush of 1849, it was not the miners who grew rich, instead it was the merchants who sold supplies to the miners. Civilian entrepreneurs may find it expedient to connect their ramshackle spacecraft together to make impromptu space stations. But remember that boom towns can become ghost towns quite rapidly.
Can be general hospitals, hospitals specializing in treating victims of spacecraft disasters, and geriatric hospitals using microgravity to prolong the lives of the elderly.
Short or long term living quarters for people. Generally includes restaurants of various quality.
A sort of combination of Space Superiority Platform and Planetary Defense. The idea is that the station is to prevent anything from entering or leaving the planet it is orbiting. A planet might be invested, meaning that the planet is under siege from whoever owns the space station. The station does not want planetary inhabitants escaping, nor does it want blockade runners entering. A planet might be interdicted because they contain something very dangerous (Xenomorphs, thionite, the City on the Edge of Forever, replicators, or 100% lethal plagues). Or the planet might be interdicted because it has something very valuable and the station owner does not want poachers sneaking in and stealing any.
Macrolife is sort of a cross between a huge habitat and a generation star ship. These are traditionally hollowed-out asteroids.
Pirate Haven
Space pirates need infrastructure (fences for pirated loot, fuel and reaction mass, ship repairs, R&R for the crew). A hidden space station can act as a Pirate Haven and cater to these needs.
Ship Docks
Short or long term storage of spacecraft.
Sky Watch
Monitors the entire sky from their location, keeping track of trajectories of known spacecraft and spotting the appearance of unauthorized spacecraft. And other important events, such as unexpected nuclear explosions. Space traffic controllers want to know trajectories of spacecraft. Orbit Guard wants to know about alterations in asteroid orbit both authorized and unauthorized. Military wants to know about enemy battle fleets. Merchant princes want to know about hostile privateers and space pirates. There will be several such stations located in widely separated parts of the solar system, for determining distance by triangulation and to make it harder for spacecraft to hide behind objects.
Space Traffic Controllers
Outer space equivalent of terrestrial air traffic controllers. Monitors and controls the flight plans of local spacecraft. Generally only needed in "crowded" areas,such as the orbital space around inhabited planets.
Space Tug Services
Groups of space tugs for hire, to move spacecraft, cargo, or other massive objects.
Tax Haven / Data Haven
These are tax shelters used by the wealthy and by corporations. They typically orbit a the planet a corporation is based on, just beyond territorial limits. More details here.
Crew Hiring
Employment services where spacecraft captains can hire crewmembers.
Transport Nexus
A Transport Nexus is a crossroad spaceport for passengers, a port of entry, an orbital warehouses where valuable minerals from asteroid mines are stored and trade goods transshipped, or a "trade-town". Will include related services, such as hotels and stevedore/longshoremen.

Naturally a given space station could have several functions.

Mr. Cambias goes on to note that stations can occupy a variety of orbits. Low planetary orbit just above the planet's atmosphere. High planetary orbit at thousands of kilometers. Geosynchronous / Geostationary planetary orbit at an altitude where the orbital period equals one planetary day (useful for communication, observation, powersat, and meteorology). Stellar orbit where the station orbits the local star instead of orbiting a planet. And Trojan orbits where the station occupies a Lagrange point (beloved of L5 colonies)

The size of a station has many terms, none of which are defined. In arbitrary order of size the terms include Beacon (like an interstellar lighthouse), Outpost, Station, Base, and Colony.

Hive of scum and villainy

Approach space stations from the bottom up, however, in a Firefly or cyberpunk manner, and you'll get a very different view of them — shady orbital stations where you can get just about anything you want... for a price. It's the perfect nexus for organized crime, given a station's importance to inter-planetary commerce and transport. Plus, in a setting with a Balkanized earth, there will likely be no serious push to police the space station in the first place unless it's run by one country alone, and in that case, I wouldn't be surprised if that country extorts anyone else who uses their spaceport.

If you want to expand on the Western analogies that are found so often in SF, then the station would be a railhead like the sort cattle-drivers used to send their cows to, with the associated markets of extortion and dens of ill-repute that go hand-in-hand with such a locale.

Ferrard Carson in a comment
Station cultures

Various sorts of space stations can exist, with different parameters leading to different societies.

High throughput ports (like the ones at the ends of Skyhook orbital elevators) will have lots of facilities for the "sailors" and "longshoremen" (they may be facilities for semi-automated or teleoperated systems), as well as maintained crews and port officials. Lots of money and valuable change hands, so corruption and crime may be rampant.

A naval support base built on a NEO will be a totally different environment; the crew and contractors will be operating under a code of service discipline, but dealing with boredom and an irregular work load.

Most asteroids will probably have very limited transportation facilities (a cycler might be by once a decade or so), unless they strike it rich, in which case they might end up like Dubai, with lots of money to import luxury goods. Otherwise, the transport is one way outbound as ices and minerals flow down the mass driver.

Given the low population density and the difficulty of surviving in hostile alien environments, most places will be like an apartment block, with everyone and everything sealed inside for protection and shelter. Expansion will probably be by driving tunnels to resource or energy nexus points and building another apartment block there, so most story settings will be quite urbanized, at least until large open Island 3 type colonies can be economically built.

Top down= navy bases and scientific research facilities. These are built for a specific purpose, and generally have little economic rational behind them, although military bases may develop garrison towns and eventually grow into larger settlements (especially when the military rational passes). If the military reason for the base fades away without any compelling economic rational to replace it, it is usually abandoned (think of Hadrian's Wall, the Maginot line or old ICBM silos).

Bottom up= trading ports, crossroads, tollgates and locks, marketplaces. They start small but their economic usefulness attracts more people and more activity, in a positive feedback loop leading to towns and cities.

There is also devolution, the port cities of the Hanse are no longer economic powerhouses, and I can see Luna going the way of Detroit after it becomes more economical to harvest 3He from the atmosphere of gas giants (the Pearson elevator to L1 is a minor tourist attraction, and L2 is a brownfield of abandoned mass catchers in parking orbits. Only criminal gangs and Libertarian squatters make their homes in and around Luna).

Of course lots of compound scenarios can exist as well; an occupying power builds a fort overlooking a captured port, or the squatters become the nexus for urban renewal because they (insert "x" here)...

Thucydides in a comment

Mr. Blue:

Some station societies would form in a very organic fashion.

Let's say there's a big rush to mine (X) in the asteroid belt and a lot of independent prospectors head out to strike it rich.

Bill figures he can make a fortune selling space suits, mining tools and the like, so he loads up a freighter and sets up shop. Sally also had the idea of setting up a hydroponic farm/ yeast vat/ and restaurant, and also headed that way. As it's a pain for a miner to make two different stops, Bill and Sally decide to dock their freighters (man, there is no way to say that without sounding dirty) and maybe even set up an extra hab for a hotel...

Pretty soon, as word gets round, other enterprising individuals begin to connect. Bits and pieces are added- an empty fuel tanker as a bar, a repair yard, or even an official buyer for (X)- sure, he doesn't pay as much, but it's a lot better that flying it to Mars yourself. And other services begin to set up shop.

Then, Billstown becomes an interplanetary destination in it's own right. After all, where else on the 'Belt can one get their ship fixed, pick up some spare hands, have a good meal and a drink, and, um, visit the Seamstresses (hem hem).

Of course, once the mining runs out (or whatever else), the boomtown becomes a ghost town. Any spaceworthy ships will be flown off, everything else may be left behind, or salvaged.

But, if the location is good enough, this random jumble of habs, freighters, and other items can become something better...

(ed note: in Terry Pratchett's marvelous Diskworld series of satirical fantasy novels, the "Seamstresses" was an euphemism for the local brothel)

From comments to Transport Nexus
Space Traffic Controllers

"Da. Engagement zones are expanded," Omer explains "United States, Europa, Bahia, all announce new requiremen five days ago.

"Sounds like transition-to-war conditions."

"Maybe. Commonwealth ships have had some problems. Some body soon maybe make a 'mistake' with a Commonwealth ship” Omer pointed out. "Or we get clearance that is wrong and take us into engagement zone. So I got from Kevin Graham new data showing positions of all orbiting objects and load into computer I will make sure clearance and trajectory do not lead us into danger."

Twenty minutes before noon, clearance came over the up-link Omer checked it and gave me a thumbs-up. I accepted it. We made a straightforward departure with the catapult slinging the Tomahok into the air at a one-gee goose. I climbed out according to flight plan and watched while the air-breathers transitioned I scram-jet mode and finally lipped-over when the mains ignited at 60 kilometers. I wasn't particularly looking for anything happen at that point because we were still in international space over the Indian Ocean.

The Tomahok was handed-off from Madras Center to Orient Center as we ascended through a hundred kilometers, expected something to happen then. It did.

"Tomahok, this is LEO Orient Center. Amended clearance."

It came on the up-link. Omer shook his head. "Bojemoi!" exploded. "Reject it!"

"LEO Orient Center, this is Tomahok. Negative the amended clearance, sir."

"Tomahok, what's your reason for refusal?"

"What's your reason for issuing this amended clearance, sir?"

"AmSpace Command request through LEO Canambah Center."

"The amended clearance takes us into the engagement zone of Gran Bahia estacao baixo doze."

"Tomahok, stand by. ... Tomahok, amended clearance: De-orbit for Woomera landing. We can't get you through."

I knew what to do, and I let it all hang out. "LEO Orient Center, Tomahok. Negative the amended clearance. We are initiating no-clearance flight under I-A-R Regulation ninety-one- point-eight. We'll take her up to Ell-Five as filed under our responsibility to detect and avoid."

Omer reached over and clapped me on the right shoulder.

There must have been consternation in LEO Orient Center because it took several seconds for the traffic coordinator to acknowledge. "Uh, Tomahok, Center, roger! Service is terminated. Proceed on your own responsibility. Retain your current beacon code."

I acknowledged and told Omer, "Get ready to thread the needle, Russkie! Let's see if we're good enough to make Ell-Five before somebody burns us with a hell-beamer!"

There I was, flat on my back at 30,000 meters, nothing between me and the ground but a thin regulation.

I'd invoked a seldom-used International Aerospace Regulation that harked back to Earth's oceans where a ship captain was an absolute monarch responsible for himself, his ship, and everything in it. It had been carried into the air by a rule that made the; "pilot-in-command" solely responsible for the safety and operation of his aircraft and everything in it, regardless of what traffic coordinators on the ground told him.

In effect, I'd told the space traffic people I'd fly without their help. Avoiding an engagement zone isn't difficult if you know where it is. Space is mostly empty.

The various STC Centers would continue tracking our beacon to keep other spacecraft clear of us. Military trackers would do the same in case we broached their engagement zones, which would mean trouble for the Tomahok.

I'd waived clearance while still under ascent thrust on our original trajectory to a 200-kilometer parking orbit. Our delta-vee margin was excellent

"Russkie, I hope the League data's good," I told Omer. "Display our current flight path and the projected positions and engagement zones of other sky junk."

"Blinking blips aren't in League data," Omer reported. The Kazakh became laconic when he was under pressure, probably because he was thinking in Russian and mentally translating into aerospace English with adrenalin pumping.

I studied the display. A blinking blip indicated a polar orbiting satellite. In parking orbit, we'd broach its engagement zone.

"There's our problem," I pointed out. "AmSpace Command recon bird. That's why the amended clearance. We'll burn out of parking orbit to miss him. What are the options?"

Omer punched the keypad. A series of trajectories came on the display. "Take high delta-vee option. It will be obvious we're avoiding the reconsat."

"But we may run into trouble with this one, Omer," I said, indicating another target with my finger. "It's displaying no code. What is it?"

Omer queried the computer. "Not in League data. Unknown."

"It's got to be registered! I'll query Center for identification."

"Let it be for now. We handle when time comes," the Mad Russian Space Jockey suggested. "We take problems one at a time. Sandy, get us in parking orbit and watch engagement zones. I work on vector for transfer orbit to Ell-Five."

Our burn out of parking orbit came as re-programmed. While, we were under thrust, we got a sensor alarm. "Targeting lidar!" I snapped. "Aerospace Force has seen us closing on the reconsat,"

"We go laser-hard," Omer said, reaching for the switch.

"Negative!" I snapped. "They'll see it, interpret it as a countermeasure, and try to burn us." I indicated another target on the display. "That's annotated as an unspecified military satellite; it's a ten megawatt hell-beamer."

"Hokay, so we do a little tsig-tsag! Give me controls!"

I did and continued to check displayed targets. Omer called out his actions. “Tsang plus-x ten meters per sec."

I got a surface temperature warning signal. "Warning shot without a call. That's not SOP!" The Aerospace Force tapped the data stream from the world STC net and they knew we were the unarmed Tomahok out of Vamori-Free.

"Maybe you got wrong freq. We did not broach engagement zone of reconsat, and now they see us burn into new trajectory. So we are out of hard place under rock for now. You fly now."

Low earth orbit zone is tricky to work in. Velocities and closing rates are high. There isn't much time to detect, track, make decisions, and maneuver. It's full of sensitive earth-oriented reconsats that are automated and passive. They can't defend themselves or maneuver. Even though such unmanned skyapies are considered to be expendable scouts, my former colleagues were sensitive about them. Everyone knew where everyone else's were, and nobody bothered them for fear of retaliation. Fortunately, sensitive satellites advertised themselves with "no trespassing" signals.

Hell-beamers were another matter. They were unmanned with auto defenses. Unless they spotted the proper beacon password— which we didn't have—they'd shoot at anything that broached their engagement zones. We had to stay clear of those. We'd been lucky once.

Some that looked like hell-beamers weren't; they were decoys or legitimate R&D space telescopes. The sensor signatures were the same. If you wanted to find out if one was indeed a hell-beamer, you had to make a hands-on inspection which was very risky not only because of the auto-defenses but also because some of them were booby-trapped.

Nobody liked the hell-beamers, especially the League of Free Traders. But the low-powered ones in LEO were no threat to people on the ground. And nobody had been burned in space by them, so they were tolerated as a necessary evil.

Think of Earth as being at the bottom of a funnel-shaped well whose walls become less steep as you climb away from Earth.

Paint the walls of the funnel in zones of different colors to represent the various space traffic control center jurisdictions. The ones nearest Earth at the bottom of the funnel are controlled from national centers that are, you hope, in communication with one another and swapping data. The ones further out are watched by seven other centers located in GEO. And the ones in the nearly-flat upper part of the funnel are four in number centered on L-4, the Moon, L-5, and a huge "uncontrolled sector" stretching around lunar orbit from 30-degrees ahead of L-4 to 30-degrees behind L-5 where there wasn't anything then.

Now spin the funnel so the bottom part representing a distance up to 50,000 kilometers goes around once in 24 hours. Spin the top part from 50,000 kilometers altitude out to a half-million kilometers at the lunar rate of 29.5 days.

Located on the walls of this madly turning multi-colored funnel are marbles spinning around its surface fast enough so they don't fall down the funnel. Some of them are deadly marbles; come close and you'll burn. Others are big and fragile, but massive enough to destroy your ship if you hit one. Still others are ships like your own, plying space for fun, profit, or military purposes. An unknown number of the last are capable of whanging you with various and sundry weapons.

Your mission: without coming afoul of any of this, get to the flat tableland on top, then locate and dock to a group of fly-specks called L-5.

Try it on your computer. Good luck.

We'd run a gauntlet of low-orbit facilities and were coming up on geosynchronous orbit. Although we were several degrees above equatorial GEO where most of the civilian facilities were, we had to get through the web of military satellites in inclined geosynchronous orbit, weaving paths around the planet like a ball of yarn.

Omer asked the computer to enhance the very weak returns from these stealthed facilities. We were going to come close to some Japanese and European targets, but not within their engagement zones unless they'd changed them and we didn't know it.

From Manna by Lee Correy (G. Harry Stine) 1983 ]

Space Habitat

The thought occured to some people (most notably Gerard O'Neill) that if the delta-V cost for traveling up and down a planet's gravity well is so expensive, the expense can be avoided if you simply live in space inside a titanic space station. The classic "L5 Colony" was about 32 km long, and held 10,000 inhabitants. Such a colony could earn its keep by harvesting solar energy or with other more shady revenue streams. A quick Google search on "L5 Colony" will reveal a wealth of details. And if you stick an engine on the end, you have a Generation Ship

It sounds very utopian, and it is.

Now, in a Rocketpunk future, when space stations are dotted over the entire solar system (or even the entire galaxy), they might start out as being just a tiny habitat functioning as a Transport Nexus. Yes, they may start as glorified airplane terminals, but they can become more than that. Space stations near research sites can become college towns, ones near mining sites can become mining towns. Then along will come people willing to import and sell things to the inhabitants, and suddenly you've got a city. Think about the TV show Babylon 5, about a space station at the intersection of interstellar transport routes between several star nations. Started as an outer space bus terminal, but grew to become a center of trade and diplomacy.

If the space city has its own revenue stream, it can go even further, and become an independent city state or station-republic. At some point they will be growing fast enough to justify investing in the construction of a full sized L5 colony.

But remember what Thucydides said above about devolution. If the space city's revenue stream dries up, the city becomes a slum, or even a ghost town. Especially if the space city is a boom town, there to supply a fine selection of expensive vices to the local asteroid gold strike or orbit guard military base. If the strike dries up or the base is relocated, the space city will die.

Space habitats appear in science fiction in the Mobile Suit Gundam Wing animes, C. J. Cherryh's Alliance-Union novels, Alexis Gilliland's Rosinante trilogy, George Zebrowski's Macrolife, John Varley's Gaea Trilogy, Sir Arthur C. Clarke's Rendezvous with Rama, and the tv series Babylon 5.

One problem is that you cannot make a small O'Neill cylinder as a pilot project to gain the expertise to build a full size one, due to the nausea caused by the Coriolis effect. Your first one has to be full sized.

A space colony is a particularly pure example of a hydralic state. If citizens make the powers-that-be (defined as "the people who control life support) angry, said citizens will suddenly find themselves trying to breath vacuum. Obey or die. The way to avoid this is with massively redundant life support infrastructure, in an attempt to decentralize control. Of course this only means you do not have to obey the space colony boss, just obey the boss of the segment you live in.

In C.J. Cherryh's Alliance-Union universe, none of the interstellar colonies are actually on an extrasolar planet. Instead they are space habitats in orbit around various lifeless planets (with the exception of Pell). The glaring unanswered question is if you are not going to be using the extrasolar planets, why did you go to the insane expense of using slower-than-light technology to create space habitats in other stellar systems? It would have been about a million times cheaper to just build the habitats somewhere in our own solar system.

If one is colonizing other stellar systems with slower-than-light starships, mass is at a premium. The expense of delta-Ving every microgram up to insterstellar velocities then braking to a halt means you won't be able to carry much of anything. It requires much lower mass to carry the needs for a colony on a human-habitable planet as compared to carrying the industrial machinery required to construct kilometer-long L5 colonies. In fact, such a colony ship might not even carry full grown colonists.

Naturally if you postulate FTL starships, all bets are off. Then it simply becomes a matter of transport costs.

This may or may not boil down to Space Habitats initially being unique to Terra's solar system.

Mos Eisley Space Station


The problem with a space station as Mos Eisley is simple. Who's providing the air? A lawless space station sounds good, but it's going to run into an extreme form of the "Three Generations Rule" from Attack Vector: Tactical. Either air will be ignored and everyone dies, or it will be the major point of conflict. No space station can survive without a single controlling power that runs the life support. The same applies to any other form of space habitat.

Neon Sequitur:

The 'Mos Eisley' concept may not work for an entire functional space station, but it makes a bit more sense if all or part of a station is considered 'written off'. Babylon 5 had a slum sector, which the station management considered not worth cleaning up. This conveniently allowed the writer(s) to have both a strong central authority on B5 as well as part of the station which resembled Mos Eisley.

In Transhuman Space, the Three Generations Rule rule might be considered a blessing when it comes to squatters in abandoned habitats. It saves the Powers That Be the expense of evicting them, or even deciding who's responsible for doing so. It's a given the life support will fail eventually. Until that happens, however, it's sort of a temporary 'tent city' version of Mos Eisley. (And that sounds like yet another pile of story ideas....)


There's no reason that this can't be worked into the plot. Our own human nations are not immortal. Our corporations can be consumed or die of incompetence. Just because Rome was not eternal did not mean it could not exist for the span it did. The vast majority of seeds do not become trees but that does not mean a forest cannot be.

Any properly vast station would have hundreds of sectors with redundant life support and power generation systems. If we imagine the station as an island in space, consider Hispaniola. On one side we have a functioning states, the Dominican Republic. On the other side we have Haiti, a dysfunctional mess. Same island, same resources, different results.

I could imagine a very interesting setting on a vast station that is suffering from the collapse of unified control. Some sectors are properly maintained and society is functioning as it should. Other sectors are in poor maintenance. Some of the common areas are completely out of maintenance, possibly open to hard vacuum. Perhaps the functioning side lacks the resources to fix the broken areas, maybe lack the manpower.

You have a story of resource depletion and civil war on Easter Island. A relatively advanced primitive society tore itself apart, likely over religion and politics. Imagine if you had a dozen islands within sight of each other, some of them maintaining social order while others descend into cannibalism and anarchy.

So as far as your Mos Eisley station example, a small one would be operated by one pirate king, the same way pirate settlements in the Carribean were founded by notable individuals. His house, his rules. Visitors pay rent. He provides the power, air, and food. For larger pirate settlements, each faction would maintain their own area. You wouldn't see chaotic evil pirates running these places, they'd be pragmatic amoral. These would be the guys you could trust in the sense that you know they are rational and have reputations to maintain in the community. You might get knifed in the back if no one is to be the wiser but they're not going to cheat you openly in a way that would harm their reputations. Get known as a cheat and no other pirate will risk doing business, savvy?

The rationale for a pirate haven like this is fairly obvious. Pirates can't get their ships worked on in legitimate yards. They need a place to handle repairs too big for the hands onboard. They need a place for R&R, can't exactly stretch your legs in places where the cops are. Ships can refit and recrew here. And there's also the need to fence stolen goods. Here pirate cargo gets traded to "honest" merchantmen and can get back on the open market.

Now any number of things can happen to jeopardize the viability of such a pirate haven and that's where the stories get interesting.


In our hypothetical space station, however, why would people who are keeping their sections in good shape provide for those who don't. Any earth analogy can only be taken so far, as we can managed to get all we need to live pretty much on our own here. The same is not true of a station, and if a sector is in chaos, the life support is going to get neglected, and that's going to lead to a crash very quickly. Atomic rockets points out that a space colony very much resembles a hydraulic empire. It simply can't be anarchy. There might be some parts that are seedy, but I doubt an entire station will be a lawless area, or even most of it. The pirate lord described is plausible, however.


Ah, good question. That's just it — it wouldn't be a hydraulic empire. For a large station, I'm imagining it being more like a condo. Stations have sections and sections are controlled by some form of polity, a faction. All the equipment necessary for survival is contained within that section. Each section beyond that is also self-supporting, just like owners in a condo -- the owner pays the note on his mortgage and nobody else in the community needs to help him on that. Of course, condos have areas of common responsibility and expense. When the organization becomes dysfunctional, that sort of stuff deteriorates. And then you can end up with the situation of individual units held onto by owners as the rest of the neighborhood deteriorates.

Now you may ask "Why would a station be built with so much redundancy in the first place?" And that would be precisely to avoid the situation of a hydraulic empire as you state. Say three factions come together to build a trading station in neutral territory. The expense is greater than any individual power can afford so they split the cost. The station is constructed. Each faction has territory on the station that they own in the clear. Furthermore, those sections are self-supporting for all essentials because they wish to avoid the chance of anyone cutting them off from the station's grid. But because there are common needs of the station, all three pay towards the maintenance of the structure and what elements cannot be easily triplicated. On paper this operations company may be considered independent and neutral with personnel drawn from all three factions or maybe from third parties. But you can well imagine how things on such a station could become dysfunctional in time.

From comments to Transport Nexus

Asteroid Bubble

Larry Niven popularized the "asteroid bubble" technique of creating a huge space habitat. Andrew Love notes that if the asteroid is made of stone, once you start to spin it for artificial gravity it will immediately fly into pieces. As he puts it "there are no stone suspension bridges". Stone is heavy and weak, particularly in tension. A 100 meter external radius asteroid made of granite and spun up to 1 gee would put the granite under stresses about twice the expected strength of granite.

You will note that Larry Niven specifies a asteroid composed of nickle-iron.

The next step up in size is the hollow planetoid. I got my designs from a book of scientific speculation, Islands in Space, by Dandrige M. Cole and Donald W. Cox.

STEP ONE: Construct a giant solar mirror. Formed under zero gravity conditions, it need be nothing more than an Echo balloon sprayed with something to harden it, then cut in half and silvered on the inside. It would be fragile as a butterfly, and huge.

STEP TWO: Pick a planetoid. Ideally, we need an elongated chunk of nickel-iron, perhaps one mile in diameter and two miles long.

STEP THREE: Bore a hole down the long axis.

STEP FOUR: Charge the hole with tanks of water. Plug the openings, and weld the plugs, using the solar mirror.

STEP FIVE: Set the planetoid spinning slowly on its axis. As it spins, bathe the entire mass in the concentrated sunlight from the solar mirror. Gradually the flying iron mountain would be heated to melting all over its surface. Then the heat would creep inward, until the object is almost entirely molten.

STEP SIX: The axis would be the last part to reach melting point. At that point the water tanks explode. The pressure blows the planetoid up into an iron balloon some ten miles in diameter and twenty miles long, if everybody has done their jobs right.

The hollow world is now ready for tenants. Except that certain things have to be moved in: air, water, soil, living things. It should be possible to set up a closed ecology. Cole and Cox suggested setting up the solar mirror at one end and using it to reflect sunlight back and forth along the long axis. We might prefer to use fusion power, if we’ve got it.

Naturally we spin the thing for gravity.

Living in such an inside-out world would be odd in some respects. The whole landscape is overhead. Our sky is farms and houses and so forth. If we came to space to see the stars, we’ll have to go down into the basement.

We get our choice of gravity and weather. Weather is easy. We give the asteroid a slight equatorial bulge, to get a circular central lake. We shade the endpoints of the asteroid from the sun, so that it’s always raining there, and the water runs downhill to the central lake. If we keep the gravity low enough, we should be able to fly with an appropriate set of muscle-powered wings; and the closer we get to the axis, the easier it becomes. (Of course, if we get too close the wax melts and the wings come apart…)

From Bigger than Worlds by Larry Niven (1974)

Confinement Asteroid is unique.

Early explorers had run across a roughly cylindrical block of solid nickel-iron two miles long by a mile thick, orbiting not far from Ceres. They had marked its path and dubbed it S-2376.

Those who came sixty years ago were workmen with a plan. They drilled a hole down the asteroid’s axis, filled it with plastic bags of water, and closed both ends. Solid fuel jets spun S-2376 on its axis. As it spun, solar mirrors bathed it in light, slowly melted it from the surface to the center. When the water finished exploding, and the rock had cooled, the workmen had a cylindrical nickel-iron bubble twelve miles long by six in diameter.

It had been expensive already. Now it was more so. They rotated the bubble to provide half a gee of gravity, filled it with air and with tons of expensive water covered the interior with a mixture of pulverized stony meteorite material and garbage seeded with select bacteria. A fusion tube was run down the axis, three miles up from everywhere: a very special fusion tube, made permeable to certain wavelengths of light. A gentle bulge in the middle created the wedding-ring lake which now girdles the little inside-out world. Sunshades a mile across were set to guard the poles from light, so that snow could condense there, fall of its own weight, melt, and run in rivers to the lake.

The project took a quarter of a century to complete.

Thirty-five years ago Confinement freed the Belt of its most important tie to Earth. Women cannot have children in free fall. Confinement, with two hundred square miles of usable land, could house one hundred thousand in comfort; and one day it will. But the population of the Belt is only eight hundred thousand; Confinement’s score hovers around twenty thousand, mostly women, mostly transient, mostly pregnant.

From World of Ptavvs by Larry Niven ()

Space Superiority Platform

Many early SF stories fret about the military advantage an armed space station confer upon the owning nation. Heinlein says trying to fight a space station (or orbiting spacecraft) from the ground is akin to a man at the bottom of a well conducting a rock-throwing fight with somebody at the top. One power-crazed dictator with a nuclear bomb armed station could rule the world! Space faring nations would need space scouts for defense.

But most experts nowadays say that turns out not to be the case. A nation can threaten another with nuclear annihilation far more cheaply with a few ICBMs, no station is required. And while ground launching sites can hide in rugged terrain, a space station can hide nowhere. Pretty much the entire facing hemisphere can attack the station with missiles, laser weapons, and propaganda.

Phil Shanton points out that you don't need a huge missile to destroy an orbiting space station, either. In 1979, the U.S. Air Force awarded a contract to the Vought company to develop an anti-satellite missile. It was not a huge missile from a large launch site. It was a relatively small missile launched by an F-15 Eagle interceptor in a zoom-climb. Vought developed the ASM-135 Anti-Satellite Missile (ASAT), and on 13 September 1985 it successfully destroyed the solar observatory satellite "P78-1". This means that an evil-dictator world-dominator nuke-station not only has to worry about every ground launch site, but also every single fighter aircraft.

It has also been modeled that the U.S. Navy could take out a satellite with a Standard Missile 3.

Things are different, of course if the situation is an extraplanetary fleet that remotely bombs the planet to destroy all the infrastructure. The fleet can construct a space superiority platform while the planet is struggling to rebuild its industrial base. Then the platform can bomb any planetary site that is getting too advanced in rebuilding. This is known as "not letting the weeds grow too tall.


Space Logistics Base

James Snead has written a few paper about space infrastructure. Most interesting is Architecting Rapid Growth in Space Logistics Capabilities (PDF file). On page 23 he gives an example of an orbiting space logistics base, including a space dock. Refer to that document for larger versions of the images below.

...the space logistics base’s functions are: (1) housing for travelers and operating crews; (2) emergency care; (3) in-space assembly, maintenance, and repair; and (4) materiel handling and storage.

The example space logistics base consists of four elements. At the top in Fig. 10 is the mission module providing the primary base control facility, emergency medical support, and crew and visitor quarters. The personnel quarters are located inside core propellant tanks that are retained from the SHS used to launch the mission module. The overall length of the mission module and propellant tanks is approximately 76 m (250 ft). Solar arrays and waste heat radiators (shown cut-away in Fig. 10) are mounted on a framework surrounding the mission module to provide additional radiation and micrometeoroid protection.

The second element consists of twin space hangars. These serve as airlocks for receiving spaceplanes and provide a pressurized work bay for conducting on-orbit maintenance of satellites and space platforms.

As shown in Fig. 11, the space hangar consists of a structural cylindrical shell 10 m (33 ft) in diameter, a forward pressure bulkhead containing the primary pressure doors, and an aft spherical work bay. These elements, which define the primary structure, would be manufactured as a single unit and launched as the payload of an SHS. The large, nonpressurized, space debris protection doors would be temporarily mounted inside the hangar for launch and then demounted and installed during the final assembly of the hangar at the LEO construction site. All of the other hangar components would be sized for transport to orbit in the cargo module of the RLVs and then taken through the hangar’s primary pressure doors for installation.

Future logistics supportability is a key feature of this hangar design. The size, weight, location, and access of the internal hangar components enables them to be inspected, repaired, and replaced without affecting the primary structural / pressure integrity of the hangar. With the exception of the space debris protection doors, this would be done inside the hangar when it is pressurized. The ISS-type airlock and space debris protection doors, although mounted externally, would be demounted and brought into the hangar for inspection, maintenance, and repair. For the repair of the primary pressure doors, they would be demounted and taken into the spherical work bay or the other hangar for servicing.

The hangar’s design enables both pressurized and unpressurized hangar operations to be undertaken simultaneously. When the main hangar deck is depressurized to receive cargo or spaceplanes, for example, pressurized maintenance operations would continue inside the 9.8 m (32 ft) diameter spherical work bay and the 2.8 m (9 ft ) diameter x 4.3 m (14 ft ) work compartments arranged along the top of the hangar.

Hangar operations in support of the passenger spaceplanes, as shown in Fig. 12, highlight the improvement in on-orbit logistics support enabled by the large hangars. After entry into and repressurization of the hangar, the passengers would disembark from the spaceplane. Support technicians, working in the hangar’s shirtsleeve environment, would inspect the spaceplane and, in particular, the thermal protection system for any damage to ensure that it is ready for its return to the Earth. While at the space base, the spaceplane would remain in the hangar to protect it from micrometeoroid or space debris damage. Minor repairs to the spaceplane could also be undertaken to ensure flight safety.

The third element is the air storage system. The prominent parts of this system are the large air storage tanks that are the reused core propellant tanks from the two SHS used to launch the twin space hangars. Besides storing air from the hangars, this system also: manages the oxygen, carbon dioxide, and moisture levels; removes toxic gases, vapors, and particulates; and, controls the temperature and circulation of the air within the hangar and its compartments.

The fourth and final element is the space dock. It would be constructed from structural truss segments assembled within the space hangars using components transported to orbit in the RLVs. The space dock would provide the ability to assembly and support large space logistics facilities, such as the space hotels and large manned spacecraft described in the following. It could also used to store materiel and as a mount for additional solar arrays.

The space hangars and space dock would enable traditional logistics operations of maintenance, assembly, and resupply to be routinely conducted in Earth orbit. This is an enabling capability necessary to become spacefaring and achieve mastery of operations in space.

The space logistics base would have approximately 20 personnel assigned. The tour of duty would be 90 days with half of the crew rotating every 45 days. Crew rotation and base resupply would require approximately 32 RLV missions per year per base with 8 spaceplane missions and 24 cargo missions. This would provide approximately 12,000 kg (26,000 lb) of expendables and spares per person per year. At $37M per mission, a ROM estimate of the annual transportation support cost per base would be approximately $1.2B.

While the LEO space logistics base would have sufficient housing capacity to support the 20 assigned personnel and a modest number of transient visitors, it would not be a primary housing facility. Since people cannot simply pitch a tent and “camp out” in space, establishing early permanent housing facilities is an important and enabling element of opening the space frontier to expanded human operations. The architecture of the Shuttle-derived heavy spacelifter and the LEO space logistics base was selected so that the first large space housing complexes, referred to as space hotels, could be constructed using the same space logistics base modules.

A composite illustration of the design, assembly, and deployment of the example space hotel is shown in Fig. 13. This hotel design is configured as a hub and spoke design with a long central hub and opposing sets of spokes attached to the central hub module. This configuration makes it possible to use variants of the space base’s mission modules and space hangars as the primary elements of the space hotel’s design.

Element 1, in Fig. 13, shows the start of the hotel assembly sequence. The central hub module, shown with the SHS’s core propellant tanks still attached, is being positioned at the space logistics base’s space dock. The central hub module would be a version of the mission module used in the space logistics base. Its design would include 12 docking ports around its circumference for attaching the spokes.

Element 2 shows the completed hub and one attached spoke. Two space hangars are located at the ends of the hub and the first spoke is shown attached to the central hub module. In assembling the hub, the core propellant tanks from the two SHS missions used to launch the hangars would be incorporated into the hub to provide additional pressurized volume. This approach would be also used for the spokes. Each spoke would consist of a generalpurpose mission module with the SHS’s core propellant tanks reused for additional pressurized volume. As with the mission module on the space logistics base, the spokes would be surrounded by solar arrays and waste heat radiators. This is what provides their “boxy” appearance.

Element 3 shows the completed 100-person space hotel with two pairs of spokes on opposing sides of the hub. This is the baseline space hotel configuration. Seven SHS missions would be required to launch the hub and spoke modules for the baseline hotel. One additional SHS cargo mission would be used for the solar arrays and waste heat radiators.

This design enables the hotel to be expanded to 6, 8, 10, or 12 spokes. Each spoke would require one additional SHS mission. The 12-spoke configuration would accommodate up to approximately 300 people. Each additional spoke would be tailored to provide a specific capability, such as research and development facilities, tourist quarters, office space, retail space, etc.

Element 4 shows the completed space hotel after being released from the space dock. It also shows how the hotel would rotate about the long axis of the hub to produce modest levels of artificial gravity in the spokes. At about two revolutions per minute, a Mars gravity level is achieved at the ends of the spokes. This use of artificial gravity enables the spokes to be organized into floors (Element 5 in Fig. 13). Each spoke would contain 18 floors with 14 of these available for general use and the remaining 4 floors used for storage and equipment. The spokes would be 8.4 m (27.5 ft) in diameter. This would provide a useful floor area of approximately 42 m2 (450 ft2) per floor. The total available floor area in the baseline configuration would be 2,340 m2 (25,200 ft2). The 12-spoke configuration, having 192 floors total, would have 3 times this floor area—7,026 m2 (75,600 ft2) or about 23 m2 (250 ft2) per person.

An estimate can be made of the number of guests visiting the hotel each year. Assuming a 3:1 ratio of guests to staff, approximately 76 guests would be staying each night in the baseline configuration and 228 guests in the full configuration. With one third of the useful floors configured as guest cabins, two cabins to a floor, each cabin would have a useful area of approximately 21 m2 (225 ft2).* With an average stay of one week, approximately 4,000 guests and 12,000 guests would visit the 4- and 12-spoke hotels each year, respectively.

If each passenger spaceplane carries 10 guests, approximately 400 and 1,200 RLV flights would be required each year. With an additional 25% required for staff transport and resupply, the 4-spoke hotel would require about 10 flights per week and the 12-spoke hotel would require about 30 flights per week. If the RLVs could achieve a one-week turnaround time, and allowing for one in five RLVs being in depot for maintenance, 12 RLVs would be required to support the 4-spoke hotel and 36 RLVs for the 12-spoke hotel.†

At the $37M per flight cost discussed previously for first generation RLVs, the per passenger transportation cost would be approximately $3.7M. With this transportation cost structure, a sustainable space tourism or space business market may not be possible. However, if a second generation RLV could reduce this cost by a factor of 10 to $0.37M per passenger, as an example, then an initial market demand for the baseline hotel may develop and be sustainable. In such case, the annual transportation revenue for the baseline hotel would be $3.7M x 500 = $1.9B and the 12-spoke hotel would be $5.6B.‡ This improvement in transportation costs would also yield a savings of 90%—approximately $1B per year—in the transportation costs to support the LEO space logistics bases. Human space exploration missions would also realize a significant cost reduction.

While developing a conceptual design of a space hotel would appear premature at this early stage of considering the architecture of an initial space logistics infrastructure, several important conclusions emerge that indicate otherwise:

1) Careful selection of the initial space logistics architecture can also establish the industrial capability to build the first space hotels necessary to enable the expansion of human enterprises in space.

2) A commercially successful space hotel will require second generation RLVs to lower further the cost of transportation to orbit.

3) In order for these second generation RLVs to be ready when the first space hotel is completed, the technology research investment would need to begin concurrently with the start of the detailed design of the initial space logistics systems. Conversely, for private investment to seriously consider building the first hotels, significant science and technology progress in developing the second generation RLVs must be demonstrated by the time the initial hotel construction contracts are made.

4) The benefits of reduced space transportation costs will also substantially lower the cost of operation of the initial elements of the space logistics infrastructure, leading to a likely increase in demand for more in-space logistics services.

5) Space hotels and second-generation RLVs may become an important new aerospace product for the American aerospace industry, establishing American leadership in this new and growing field of human astronautical technologies.

6) It is not unrealistic to expect, with the building of an integrated space logistics infrastructure, that hundreds of people could be living and working in space by 2020, growing to thousands of people by 2040 with many of these living in the first permanent orbiting space settlements.

* A standard cabin on the new Queen Mary 2 cruise ship has an area of 18 m2 (194 ft2). A premium cabin has an area of 23 m2 (248 ft2).

† Launch sites for these RLVs would be distributed around the world. This would allow operations at the space hotel to run 24 hours per day since there is no day and night in LEO.

‡ This further reduction could come about through the introduction of a spiral version of the first-generation RLVs where improvements to the high maintenance cost subsystems, e.g., engines, could substantially reduce the recurring costs. Another approach would be development of entirely new RLV configurations—perhaps a single-stage configuration—that would also result in a substantial reduction in recurring costs per passenger through subsystem design improvements and the ability to carry more passengers per trip. A key issue in both approaches is the amortization of the development and production costs. High flight rates, probably dependent on space tourism, would be required to yield an overall transportation cost sufficiently low to enable profitable commercial operations.

NASA Space Station: Key to the Future

This is from a 1971 brochure from NASA called Space Station: Key to the Future, as documented by David Portree. The station is cylindrical with a diameter of ten meters. The station is somewhat extravagant, down to the wood panelling on the crew quarters.

Quick Assembly

This clever design solves the problem of how to quickly assemble a wheel space station, with one tiny little drawback. You see, there is a reason that wheel space stations are shaped like, well, wheels and not like hexagons.

The amount of centrifugal gravity experienced is determined by the distance from the axis of rotation (the greater the distance, the stronger the gravity). So if you want the amount of gravity to be the same, the station has to be a circle.

Now, look at the image below. The segment labeled "SPACE STATION RIGID MODULE" is one of the hexagonal sides. The green lines lead to the axis of rotation (i.e., that is the direction of "up". Note the little dark men figures, they feel like they are standing upright). And the red lines are lines of equal gravity. You will note that they do not align with the module.

In the module, centrifugal gravity will be weakest at the center of the module, and strongest at the ends where it joins with the neighbor modules. Even though the module is straight, the gravity will feel like it is a hill. If you place a marble on the deck in the center, it will roll "downhill" to one of the edges.

As you see, the designers tried to compensate for this by angling the decks, but it really doesn't work very well.


Somewhat more elaborate in conception is the 94 ft wheel-shaped satellite prepared by two design engineers of the Lockheed Missile Division. This celestial laboratory for a crew of 10 weighs 400 tons, and is intended to orbit at a height of 500 miles. Each pre-fabricated section is 10 ft in diameter and 20 ft long, fitted with airlocks, and weighs 10 tons delivered into orbit. Powerful 3-man "astro-tugs" would round up the orbiting packages and couple them up. The entire operation should not take more than a month. The whole design has been investigated in exceptional detail, and is complete with nuclear power reactor and propulsion unit for changing orbit, astronomical telescopes, computer room, space-medical laboratory, airlocks for access, etc. All gravitational worries would be relieved by rotating the vehicle about its hub, which would remain stationary for observational purposes.

The Lockheed space station made an apperance on the 1959 TV show Men into Space. I have not seen this show, but from what I've read it was astonishingly scientifically accurate. Certainly more accurate than most anything from TV or movies in the last couple of decades. Thanks to Drake Grey for bringing this to my attention.

Herman Potocnik Design

This is from those innocent days before the discovery of nuclear power. The station uses solar power in the form of mercury boilers, since these were also the days before the discovery of the photoelectric effect.

Smith and Ross Design

Station desgined by R.A.Smith and H.E.Ross (circa 1940). Again, the station is powered by mercury boilers. The telescope uses a coelostat to counteract the spin of the station. The antenna support arm is de-spun to allow a spacecraft to dock, then is spun up to allow the air-lock module to mate with the station habitat module.

Fortress on a Skyhook


High Crusade

Apparently the artist who did the book cover had seen this old Soviet space station design. I have not been able to discover any details about the station, except that the model is apparently hanging in some Russian museum.