Planets: Who Needs 'Em?

Sailor, I agree. But then I'm an Asteroid /Comet man myself. BTW, you COULD just hollow out large asteroids, mount engines and use them if you didn't want to build so pretty.
Victor

From: sailor.barsoom
Sent: Thursday, September 16, 2010 4:48 PM
To: spacesettlers@yahoogroups.com
Subject: [spacesettlers] Planets: Who Needs 'Em?

Here is something I just posted in the Science Fiction Community at Amazon. It runs just under twelve hundred words. http://tinyurl.com/2wkfbzs

In much of science fiction, people use space ships to travel from one planet to another. This usually involves faster-than-light travel, but sometimes involves long voyages of decades or even centuries. On these longer trips the crew might be kept in suspended animation, the ship may travel so close to the speed of light that the crew only experiences a few months in the century or more of travel time, or the ship may be designed to sustain generations of people, from womb to tomb, and it is the great-great-great-grandchildren of the original crew who finally make it to that planet.

In this later case, this ship is what is called a "generation ship" and the journey will usually be one of colonization. The inhabitants of the ship (it hardly makes sense to call them "crew" anymore) will be excited to have finally arrived at this new world, this new home. They will descend from the only home they or anyone they've known has known for generations to hew out a new habitat from this wild, dangerous, untamed planet.

Why? The ship has everything needed to sustain life, or the fifth generation (or more) removed from the original colonists wouldn't be doing anything. Unless the ship is a dreadful place to live, like being in prison or something, why bother with that planet?

And why should the ship be a dreadful place to live? Who would design it to be unpleasant? Would you condemn yourself, and your children, and your grandchildren, and (you get the idea) to lives their entire lives in some space-borne Alcatraz? No, of course you wouldn't. So the ship is probably a fairly pleasant place to live, and has all that you need.

Now, the argument can be made that even a very large generation ship is only so big, and that the planet is needed so that your population can grow beyond the few thousand aboard. But why? Those few thousand have been enough for generations, or it wouldn't be a generation ship.

Consider also that a ship designed to hold generations of people can be pretty freaking big. It has to be big, to carry enough population to avoid severe inbreeding. With today's materials, they could be ten or twenty Km in diameter and dozens of Km long. That's without carbon nanotubes or some special unobtanium material. With nanotubes, they can be two thousand Km across, though that may be a bit much for a ship intended to make a long journey.

Finally, now that you have arrived at the new planet, you have the resources of a solar system at your disposal. You can build more ships. A dozen more, until the population grows, and then you have the manpower to build hundreds, and then thousands. You can build ships bigger than were practical when you needed to move star-to-star. However spartan your generation ship was, you can now build world-ships. From a few asteroids and comets, you can build so many world-ships that you actually have more living space than that planet you were so excited about has to offer.

Now let's look at that planet. How Earthlike is it, really? In many stories, the answer is "not very." The gravity might be high, there might be radiation storms, the air isn't quite right, and there are often hostile life forms or even a native population who doesn't want you around. This all makes for exciting storytelling, but why would you endure all that if a better alternative is available? An alternative which can provide more living space and more comfortable conditions?

A new, unexplored planet, simply because it is new and unexplored (and so honking BIG) will offer a call to adventure which will be irresistible to some. A few of those explorers may even decide they want to live there, fierce, indigestible wildlife and all. But most will be happy to stay in their more civilized world-ships.

An argument could be made that such ships are fragile, compared to a planet. This is true, but aside from the Pellucidar of Edgar Rice Burroughs, people don't live in a planet's interior. They live on the planet's surface. I'll say it right out: there is nothing that will destroy a well-designed world-ship that will not also destroy a city on the surface of a planet. Just because the planet under your feet survives doesn't mean that you will. The only way a planet-bound city would be more disaster-proof than a world-ship is if it were dug in beneath a few hundred metres of solid rock. But you wouldn't make every city the equivalent of Cheyenne Mountain unless you were expecting the equivalent of nukes to hit your cities. If the planet is so dangerous that every city has to be a nuke-proof NORAD-esque bunker then why are you settling there? Aren't there any nicer planets available? In some stories, the answer is no, there are no nicer planets available. They've all been taken, or Earth is uniquely hospitable, or something like that. Thus an even stronger reason to give up planets and build thousands of ships.

The advantage of being able to build underground is somewhat offset by the fact that a world-ship can move. Finally, keep in mind that even something that destroys a planet can't kill a civilization spread throughout a solar system. A civilization on a planet is one planet-cracker away from extinction. A civilization of seven trillion spread throughout a solar system can have 99.9% of its population wiped out, and still have more survivors than the population of Earth today.

And think of all the solar systems available! If you want to settle a planet, you have to find a planet. And not just any planet: it has to be the right size, the right mass, the right composition, the right distance from its star. It has to be Earthlike from the start or able to be terraformed within a few generations (else what's the point?). How common are systems with planets like that? But almost any star will have asteroids and comets. Thus, almost any star will support world-ships just fine.

I think that the generation ship story, in which thousands of people are born, grow up, live, and die, generation after generation, over the course of a few hundred years aboard a huge vessel able to provide the necessities of life, just to set up camp on an inhospitable ball of rock, is obsolete. It can be an enjoyable story, in the same way that all those Tarzan stories where the ape-man finds one lost city after another in the African interior can be enjoyable. But nobody will buy a dozen or more lost civilizations anywhere on the surface of the Earth today, and I'm not buying the generation ship to settle a planet idea anymore.