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How will Space Travel and Space Commerce be conducted when the best propulsion systems are constant acceleration, slower than light, drives?

by Roger Bourke White Jr., copyright 1997, August 2002, updated with ownership section Jan 2003

Chapter Two: The ramifications of these calculations

Even with constant acceleration technology, the galaxy is a big place, and it takes a long time to move around it.

In the planetary perspective, constant acceleration travel is still too slow to be of interest. But from the space ship perspective, it may be sustainable.

The question becomes: is it possible to sustain commerce with such big travel times involved? We can look for some historical precedents in our Earthly experience.

The most similar period here on Earth is the economic trade between Europe and the Orient, and Europe and the Americas, in the 1500's to 1700's. In that era sailing ships traveled from Europe to the America's in about 30 days, and to the Orient in about a year.

This model says that two years of travel is about the limit for which trade makes sense: a ship can travel about 60 days for commodity raw materials (dried fish and wood from North America) and about two years for specialty items (spices and silks from China). When travel times took longer than that, trade was pretty small in quantity.

The gross profits also have to be gigantic by modern standards. A history professor who studied the spice trade in that era told me the margin was about 3,000% on spices.

Two societies: Planetary and Space Ship

Because of the enormous differences in time flow between those staying at home and those traveling, mankind will break up into two distinct societies: those who are living on planets, and those who are living in space ships. Further, planets will have little to do with each other directly -- they are just too far apart! How much of interest can an Alpha Centurian say to an Earthling, when the turnaround time for a message is eight years? There will be many things at first, but without "current events" to sustain it, that flow will dwindle to a trickle. The planetary people will count on the space ship people to handle much of their interstellar affairs.

This means that interstellar space ships used for commerce will be city-size affairs because they must sustain a complete and self-viable community. There is no "going back home" for a spacer, so he or she must bring his or her home with them -- all of it -- the home and the community that sustains the home.

These commerce ships will approach each solar system they enter as a stranger. Because of the differences in time flow -- except on the shortest journeys -- all the planetary people that they did business with previously will have aged enormously. They may be dead, their children may be dead, their civilization may be dead... even the species may have been superseded.

Mixing Genetics and Space Travel

We don't have FTL technology, but we do have genetic engineering. How can genetics affect space travel?

From the spaceship frame of reference acceleration is important, so the higher the acceleration that can be sustained, the shorter the travel times become.

Mankind is well-adapted to one G acceleration, and not well adapted to much more than that.

It should be possible to engineer a "dwarf" race of humans with robust limbs and circulation systems. This race could feel comfortable in a two G environment, perhaps a bit more.

And more is possible... If a body is buoyed up by floating in water, then even more G's can be sustained. I propose "porpoise people". These are genetically modified people, or cetaceans, who spend their time swimming. I suspect these people should be able to sustain up to five G's, or so. The limiting factor may be overcoming the high pressure side effects of high-G, and simply getting air into these beings' lungs.

Once an organism is floating in water, higher G forces start acting like higher pressure. So organisms that are well adapted to living deep in our earthly seas may provide sources for even higher G-adapted beings. I propose "squid people" as the ultimate high-G organisms that can come from an Earthly origin. They could perhaps be comfortable at ten G's.

Beyond carbon-based life, we can turn to silicon-based life: robots of some nature. These may be good to about 20 G's.

The Mixed Bag of Space Ships

As space commerce becomes well established among many worlds, I envision a mix of all these kinds of ships and races. The one G "space liners" will carry tourists and colonists who aren't in a hurry. These will be crewed by a mix of planetary humans and dwarfs. Next up will be the pure dwarf-crewed liners that travel at two G. Passengers and cargo won't do much while they are traveling on a two-G ship, but they will get to their destination more quickly... and so on up the line. The silicon-based ships will arrive at distant locations almost as quickly as light itself, but the kinds of cargo that can survive 20 G acceleration for several years will be limited.

The Pace of doing things

Space commerce in an STL - based world system will not be as fast-paced as in a "warp" world system, and commercial encounters will often be one-shot affairs.

As a spaceship flies into a solar system, it will be attempting to determine at what tech level the planetary civilizations are currently at. They could be advanced, or they could have blown themselves back into the Stone Age. The spaceship will also be trying to determine what it has on board that will be interesting trade articles for the inhabitants.

The planetary inhabitants will, likewise, see the ship coming in as a time to see new novelties, and to dust off and assemble the best that the planet has to offer.

Both sides are concerned that the other will "defect", rather than "cooperate." (The terms defect and cooperate are used here in reference to The Prisoner's Dilemma). And, because these trading sessions are essentially one-time affairs, there is a lot of incentive to defect. The situation will resemble a 1600's European sailing ship docking off a Polynesian island to trade with the natives, or an Ancient Greek trader plying his wares with the barbarians on the Dalmatian coast.

Interstellar Conquest

Interstellar conquest makes no sense in this world-view. There is nothing that one planet can do to another over such distances and time. Intrastellar war -- war between planets and colonies within a single solar system -- can be sustained meaningfully.

Piracy can also be sustained -- a space commerce ship may take over a planet, or vice versa, for a while.

The concept of ownership

Concepts of ownership and accounting will have to change when compared to how things are done on Earth. Consider a cargo being taken by a jet pilot from London to Hong Kong. Does the jet pilot own the cargo he is carrying? Does he own the plane he is flying? It's not likely. On Earth, ownership has long been separated from operation, and, thanks to insurance, from risk. This ability to separate ownership, operation and risk has been enormously important to making commerce profitable.

Now consider the case of the interstellar space ship hauling commercial cargo. Keeping in mind that it will take decades to millennia in the planetary time reference for a space ship to make it's journeys. Is the spaceship likely to be owned by someone other than the crew? Is the cargo likely to be owned by someone other than the crew? This "model" of having the ship and the cargo both owned by the crew dates back to perhaps to the ancient Greek merchants who between harvests took a ship of good up the Dalmatian Coast to trade with the barbarians... if this model ever existed at all.

Why is this concept of who owns the ship and the cargo important?

It's important because it raises the question of who's going to pay for building an interstellar commercial space craft? Is some "mother planet" going to pay for building the city-size commercial spacecraft? If it is, it will be doing so out of pure altruism because the return on the investment will be decades to centuries in the future. The mother planet will only see a return on it's investment when the craft comes back with it's cargo hold full of interstellar exotics. Further it will take a lot of trust on the part of those investors on the mother planet because what law is going to enforce that the ship come back? Under these harsh circumstances, how often will a planet feel like "mothering" a star ship?

If planets are not going to see profit in building starships, how about other starships? Because all starships will have their clocks slowed by relativistic travel, the time problem is not so severe, but because starships will be traveling to many different places, the distance problem will become worse. Even in ship-to-ship frame of reference, the problem of how to pay back the investment in building an interstellar ship will remain formidable.

A possible solution: piracy

It may be possible that most spaceships are built by a mixture of spaceship and planetary resources, but not in a straightforward or legal fashion. It may be that a common tactic for building a new ship is that a technologically advanced "mother ship" militarily conquers a well populated primitive world, and forces the world to build a new "daughter" starship. The mother space ship is, in effect, a pirate, who temporarily takes over the planet, and devotes the planet's resources to the ship building task. When the new ship is complete, both ships leave, and the planet recovers its independence. The mother ship has invested time and intellectual resource, the subdued world has provided labor and materiel.

But piracy is not an efficient way of manufacturing things. So, until a commercially regular and trustworthy way of building interstellar ships is devised, the building and financing of ships and cargos will be a severe bottleneck in the growth of interstellar commerce. 


And there you have it: the outline of a world system based on STL, constant acceleration propulsion technology. It's a world in which stellar systems don't interact directly with each other, but count on "space ship society" to interact with them.

The space ship society is distinct from the planetary societies. The space ship will be a community unto itself, and, using genetic engineering, it can become a widely diverse bunch of humanity. Spacers can be planetary humanoids, dwarf people, porpoise people, squid people or cyborgs.

The interactions between spaceships and planets are essentially one-time interactions. Even if a space ship is making regular stops at a solar system, planetary time passes so quickly that the space people will meet with different planetary people each time they come.

The building of interstellar ships will be financially difficult long after the technological problems are solved because there is no way to get a direct return on investment. And this difficulty will "rate limit" the growth of interstellar commerce until the difficulties in financing ships and ships' cargos are solved.

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