“There is No Planet B”: The Impossible Problems of Generation Ships

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.


Subscribe to this thread