Kim Stanley Robinson’s recent piece in Scientific American marks the second time he’s written in as many months about the viability of generation ships as mankind prepares to explore the stars. That’s not surprising, considering that Robinson’s new book Aurora (which was published in July 2015) tracks a massive generation ship and its seven or so generations of humans as they make their way to the Tau Ceti system (“only” 12 light-years away) to start a new human colony. What’s interesting about his two pieces are that they’re both pragmatic verging on pessimistic: He lists so many biological, psychological, and sociological barriers and complications that readers—of these articles, at least—will be convinced to stay firmly put.
In both pieces (the first published in Boing Boing late last year), Robinson comes to the same conclusion: “There is no Planet B.” For all that generation ship stories have been a long-enduring subgenre of science fiction, the deck is stacked against us in a myriad of ways: Getting to a habitable planet will take generations. The humans who keep a generation ship running are most likely not the same ones who will see their new home. Keeping an ark—because it’s so much more than a mere ship—running is filled with so many variables involving radiation exposure, social systems, and the fragility of the human mind and spirit. With each point, Robinson returns to the notion that Earth is our only home.
And yet, we can’t stop looking upward and projecting ourselves—in thought, if nothing else—outward to other systems. So, let’s look at each of his obstacles, because you can bet there’s been a generation ship story that addresses (if not also tries to solve) it.
The ark itself must be:
- Big enough to support ecology… Most important, Robinson says, is a fully recycling ecosystem. Not surprisingly, he addresses this in Aurora: The generation ship is made up of twenty-four biomes recreating different areas of Earth, and carries about two thousand passengers.
- …but small enough to travel at quick speeds. This limits the humans’ exposure to cosmic radiation (Space.com put together this neat infographic explaining just how huge a problem radiation is to space flight.) and minimizes breakdowns in the ark itself. But when Aurora opens, the ship’s chief engineer and de facto leader, Devi, is finding more problems than she has time to fix. Most of them couldn’t have been anticipated by those who created the ships on Earth, understandably, but it’s the latter generations who must bear that responsibility. Which brings us into the most vital part of the ark…
Culture of the ship:
- More than one generation is needed to keep the ship going. Rather than busy themselves with the effort it takes to raise unique people, generation ship crews should just take a page from George Zebrowski’s Macrolife and clone everyone! Or you can go the route of Beth Revis’ unsettling but oh-so-compelling Across the Universe, in which 100 VIPs from Earth are cryogenically frozen on the generation ship Godspeed. Multiple generations spool out during Godspeed‘s voyage, but their real purpose is to ensure that these cryo-pods stay perfectly preserved. Once unfrozen, these Earthlings will be the first to step onto their new planet.
- Enforced reproduction to maintain population control. You can make this very clear, like on the Syfy miniseries Ascension, which made reproduction a privilege handed out through computer algorithms and annual fertility festivals. Or you can go the route of Across the Universe‘s Elders, who pump pheromones into the air and water, and establish mating seasons.
- Mandatory jobs. In addition to strictly controlling breeding, Rob Grant’s farcical book Colony sees crew members inheriting their parents’ jobs on the ship… which goes about as well as you would expect, with later generations developing personal beliefs that distance them from their duties to an alarming degree.
- The establishment of a totalitarian state. Most of the stories try this, and it never works out well—especially when there’s a murder, as in David Ramirez’s The Forever Watch, and the totalitarian state is trying to cover it up. James P. Hogan’s Voyage from Yesteryear, in particular, shows what happens when a generation ship full of an authoritarian regime tries to rein in the Chironian branch of humans who have created their own society on a distant planet.
- Psychology of enclosed spaces. A Million Suns, the sequel to Revis’ Across the Universe, addresses the chaos and depression of realizing that neither you nor your children will ever see anything but the inside of a ship. Long before that, Robert A. Heinlein took this notion to the ultimate extreme with Orphans of the Sky, in which the remaining survivors on generation ship Vanguard believe that the ship is the entire universe.
- Untrustworthy AI. This isn’t in Robinson’s argument, but it’s a useful point. If we trust an artificial intelligence with anything concerning our fate, and it evolves as we evolve over the generations, the power dynamic will undoubtedly shift. Just ask the crew members in Pamela Sargent’s Earthseed.
Getting to a new planet:
- The rights of preexisting life. If the planet is “alive,” Robinson says, humans will have to learn how to exist with any preexisting lifeforms, in ways that will likely range from innocuous to fatal. We’re talking anything from the prions (essentially “bad” proteins that cause neural degeneration) in Aurora to pterodactyl-like creatures in the conclusion to Revis’ trilogy, Shades of Earth.
- The struggle to terraform. This will take centuries, and will require that the ark, after getting its crew to the planet, continue to function as a shelter and ecosystem. And if your planet has no sun, like the unfortunately-named Eden in Dark Eden, your generation ship will become a strange place—part prison, part home base as you wait for a rescue from Earth that may never come.
So, yeah, there are a lot of barriers to generation ships even getting in the sky, let alone to colonizing a new planet. But we’ll keep writing and reading these stories, because they hold up a mirror to what we need to fix about our own society before we can contemplate starting over on a new world. Personally, I hope we’re still able to make generation ships a reality, even if I’m long-dead when it happens. While Robinson’s first piece on Boing Boing makes it sound like there is absolutely no alternate planet for us, his conclusion in Scientific American is more hopeful, or at least conditional:
The preparation itself is a multi-century project, and one that relies crucially on its first step succeeding, which is the creation of a sustainable long-term civilization on Earth. This achievement is the necessary, although not sufficient, precondition for any success in interstellar voyaging. If we don’t create sustainability on our own world, there is no Planet B.
Gregory Benford on Centauri Dreams has criticised KSR’s “implausible plot fixes” in Aurora: http://www.centauri-dreams.org/?p=33736
If you can build and maintain a generation ship, why do you care about finding a habitable planet at the other end?
And why would a society the size of a small village turn into a totalitarian state? I would think that with such a small population the real problem would be trying to maintain the skill base needed to run the ship.
For another example, I would look at the recent game, Xenoblade chronicles x. Sure, they have a lot of luck on their end, but the way they survive the trek is interesting, as well as how they deal with their new home.
have the skill set to maintain a ship is great. but your going to need parts replace things that great broken. watch the 1st season of The 100. they had skill set but the space station was falling apart.
I liked Non-stop but I should read Heinlein’s book, also.
It is quite possible to build a habitat or starship with respectable radiation shielding comparable to that on the earth’s surface. The radiation shielding of the earth is limited mainly by our atmosphere. The thinnest is straight up, at sea level that is 14.7 lb mass per square inch at sea level. However a whole lot of inhabited places are way above sea level and so have much less thick shielding.
If you look at the lowest radiation shielding on earth you can find inhabited places at altitudes such that you have less than half that mass per square inch straight up.
Then you can realize that the larger the ship, the more volume it will enclose for the same shielding thickness. Basic cube square law.
The idea that starships or long term space habitats are “impossible” is flatly wrong
Well, I feel better now. (Not really.)
But certainly, that final quote is a great one. Uncertainty about the future of this planet may be one of the prime motivations in looking for someplace else, but unless we start doing a much better job here and now, we aren’t likely to get the chance to try.
@7 Apart from the headline, which is hyperbolic by virtue of being a headline, the first use of the word “impossible” in this article was your comment. Who exactly are you arguing with?
Also, calling something “flatly wrong” works better if you know what you’re talking about. We’re protected from radiation by Earth’s magnetic field, not by the atmosphere. An example of this is provided in the awesome image below.
#9 – Amusing. You should follow your own adage about knowing what you are talking about.
Magnetic shields only work against charged particle radiation, they don’t work at all against energetic light radiation such as gamma rays, as was mentioned in the article as a problem issue in long-term survival in space, which is true. Magnetic fields work badly against cosmic rays which are charged particles traveling at relitivistic speeds (near light speed), but these are rare. Thrown off by energetic distant events in the universe, supernova and the like.
Aside from that, one can stop charged particles with much lighter physical shielding than our heavy atmosphere. The threat of charged particle radiation is how it would damage the chemistry of the earth’s atmosphere.
The article talks about the impossibility of habitats and generation star ships – “With each point, Robinson returns to the notion that Earth is our only home.” Which is nonsensical, as if humans should never have left Africa.
Exiles trilogy by Bova. The first book hasn’t aged well, but the other two are very good.
Pournelle and Niven’s Legacy of Heorot is set on a planet after the ship gets there and is pretty good. The sequels are not particularly good.
Someone peed in Robinson’s Cheerios lately. I know who I’m not letting on MY generation ship, Mr. Grumpypants.
12# as If I would board a generation ship Max Field Gardner had anything to do with!
Harrrumph!!
Generation ship actual staff is a small set of “workers” to maintain the ships operation during the “flight”
Probably AI or remote controlled robots with a few human workers selected/grown to oversee operations and repair.
The majority of ship itself will carry’s embryos of humans and animals that will be born on the planet as conditions
permit. This keeps ships actual resources are kept a bare minimum, with most of the ships resources used for
ship maintenance and power. Once a habitable planet is found the first group of human embryos will allowed to mature
either on the planet or in orbit, depending on the planetary condition. The ship at that point will be cannibalized/converted
for colonization purposes. The first group probably only be a hundred personnel. Followed later by larger groups.
Okay, first somebody is going to have to raise those embryos and educate them so maybe you should have more adult crew to train them. That said why not a shift system, so many years/months awake so many in hibernation so nobody spends their whole life on a ship – maybe not even years depending on how many in the crew and how long the voyage.
@14, @15,
This is presuming that a reliable hibernation system can be created
I think the technological problems of a generation ship have barely started to be examined, but I think they pale besides the sociological problems. You’ve got a multi-generation ship. The original crew has all died; their children have all died; what you have left is their senescent grandchildren, middle-aged great-grandchildren, and mature great-great-grandchildren. They’ve kept their home functioning for well over a century. They get to their destination.
And don’t want to leave home to go onto some weird place where they have to live in mud huts.
Very Good Point Swampyankee!
@16/swampyankee: That’s what happens in Ursula Le Guin’s novella Paradises Lost. The people eventually split up. A minority, called Outsiders, colonises the planet, the majority, the Voyagers, go on with the ship.
@18
I’ve read at least one book where that split occurred and a major plot point was dividing the resources: the settlers couldn’t survive without equipment the people who wanted to stay on the ship also needed.
I feel a visceral rage at KSR’s argument’s, disagree strongly with many of them, and loved Aurora and am grateful he made the points he did.
So much of today’s SF is dystopian. Although things have not gone well on earth, and the ship and her people have a hard time of it, Aurora tells a story of a believable future with people who have hopes and dreams, people who struggle as we might. Robinson wrote it with a provocative agenda. Great. He got us thinking, imagining, wondering. Arguing.
My wife says a movie was a waste of time if we come out of the theater and all we have to say is, “Where do you want to eat?” So it is with a book. I only have time for a finite number of books in my remaining years. I like the books I read to make me think.
“Rather than busy themselves with the effort it takes to raise unique people, generation ship crews should just take a page from George Zebrowski’s Macrolife and clone everyone!”
That doesn’t make any sense. Clones have to be raised just like anyone else. Unless you have memory transfer technology, but that’s a huge game changer. I’ve always seen generation ships as the minimal tech (despite the large size needed) approach to interstellar travel: no AI, no hibernation/suspension, no relativistic high speeds, just a big habitat trundling along. You need very good recycling and fission power, probably with breeder reactors, both of which strike me as “we can probably do it with at most one Manhattan Project of engineering research” whereas the others are “may not be possible” (human coldsleep, sub-stellar fusion power) or “may be possible but with arbitrarily high difficulty” (AI).
Cloning (without memory magic) *could* help the genetic diversity problem, though you’d still want a big sperm and egg bank, and might make it more likely that the next generation likes their roles (since you’d reduce the genetic difference between them and the generation that chose to be crew in the first place.)
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Both Earth’s magnetic field and Earth’s atmosphere protect us from radiation. At sea level there are 10 tons of air above each square meter. That’s a lot of shielding. If you used rock the ship would need about 3 meters of outer wall thickness for a similar effect; if ice, 10 meters; iron, 1 meter. (Ignoring some different effects of light vs. heavy nuclei.)
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Parts: most authors don’t try to tell a story where everything goes right (Ken MacLeod’s _Learning the World_ might be the best example, and IIRC that’s more a ship of immortals who have one generation of kids near the end), but I’d expect that to not be a problem. You’d have multiple spare parts for everything, plus some raw material and as much fabrication capability as you could squeeze in. You’d have calculated the expected failure rate of each part over the journey, then added some buffer for redundancy.
Well, ideally. There’s always the chance corruption and cost-cutting, like sub-standard construction today. Or a very expensive tomb for your political prisoners.
@10
Leaving a continent is hardly the same as leaving the entire planet.
The only thing even vaguely akin to an interstellar journey would be the longer jumps across oceans, but even the incredible Polynesian voyages are orders of magnitude easier, with their level of technology, than would an interstellar voyage be with foreseeable levels of technology.
For one thing, they didn’t have to worry about maintaining a complex culture for multiple generations in a fragile environment. They also failed at it at least once, most famously in Rapa Nui (completely deforesting one’s homeland when a major protein source is fish is not exactly a success).