The last panel I went to at Norwescon 44 completed the circle by bringing it back to interstellar travel. This one was about the technical details of how to get there, specifically looking at the concepts of the generation ship vs. hypersleep (“suspended animation”). From the program guide:
Hypersleep vs. Generation Ships
Even if faster-than-light interstellar travel isn’t possible, we’re still going, right? Or someone will. Humans are like that. But how? The two most popular notions are hypersleep (also known as suspended animation, the idea we’ll just take a nap until we get there) and generation ships (self-contained, self-supporting ecosystems like a huge sealed-glass garden). How would you prefer to go?
Peter N. Glaskowsky (M), Michael “Tinker” Pearce, Dr. Sean Robinson
Hypersleep
The main problem with any kind of suspended animation scheme is that the technology doesn’t exist for it (yet). There has been some progress, though. Apparently, doctors have successfully brought back people who have been brain dead for up to two hours. There may be a theoretical limit for that sort of thing, though, and the limit is likely measured in hours, not days, and definitely not decades.
There are other animals that hibernate, and we might learn from them, but one problem is that hibernation doesn’t stop aging. So, spending 80 years in hibernation, even if it could be done, still means you wake up 80 years later, and all you’ve accomplished is losing most of your life.
Freezing, by the way, destroys pretty much every cell in your body. Mummification actually preserves the body better than cryogenically freezing it does. And it doesn’t preserve it anywhere near the point where it might get brought back to life.
Generation Ship
A “generation ship”, for those not familiar with the term, is a large space ship designed to take multiple generations to get to its destinations. The ones who arrive might be the great grand-children of the ones who left.
Ethics
A generation ship is ethically fraught. You are dooming some generations to life aboard the ship, with no purpose other than keeping the ship running and reproducing enough so that people at the other end of the journey can have a life on a new planet.
Then again, children never get to choose where they grow up, or the circumstances of their life, or the options that are open to them.
But on Earth, there are a lot more possibilities for change. On a ship, choices will be significantly more constrained.
Logistics
You would need gravity of some sort. Rotational gravity is the easiest to do – just build the ship in a huge cylinder and spin it up. It is possible, though difficult, to do this while accelerating. (Most likely, what you’d need to do in a generation ship is accelerate for a while, then coast for a few generations while spinning, then decelerate (i.e., accelerate in the opposite direction)).
Support from Earth is possible. They could send out small shipments that could accelerate far faster than a manned ship could, and these could get even better as more efficient propulsion methods are created.
Your ship doesn’t really need a full ecosphere to keep the colonists (or their ancestors) alive, just enough to make food and recycle air and water. Pretty much everything will need to be recycled.
Story Ideas
- Hypersleep is great for a group of people waking up after some problem, partway through the journey, in an unknown environment.
- On a generation ship, all jobs needed to maintain the ship will need to be filled, and there is a limited number of people to fill them. What to do if there is a role that nobody wants to fill? Or what if there are more people than there are jobs? Would capitalism be possible, or would the constraints of the ship force a purely communist model on the inhabitants?
- Related to that, the skills needed when arriving aren’t the same skills needed along the way. How are those skills taught? Even if you leave with people who know what to do to colonize a new planet, and they teach subsequent generations, you will arrive with people who’ve known nothing but life aboard the ship, and who have learned all the skills they know from people who have never practiced them themselves and are only familiar with them theoretically.
- This is a good argument for having a complete ecology aboard the ship that requires constant effort on the part of the passengers to keep alive.
- A lot of the skills – engineering and the like – will be still used along the way as well as at the new planet.
- It can take years to become good at something. How hard is it when starting from scratch, with nobody around who has practical experience in doing it?
- A generation ship will likely only have enough fuel to stop once. So, once it’s launched (or, once it’s finished accelerating up to its cruising speed), it’s committed. It can’t come back.
- If it’s a multi-level spinning circle, the gravity will change based on how close to the hub you are. Might a stratification of society evolve based around this change?
Story Recs
Various things brought up by the panelists and audience. I haven’t seen/read most of these (yet).
2016 movie “Passengers”. Crew is in hypersleep until one of them wakes up.
Star Trek: Voyager episode The Disease – the crew encounters a generation ship.
Ascension – miniseries about a generation ship, deals with some of the psychology and ethics. “At some point in early adulthood, you realize you’ve met everyone you’re ever going to meet, and gone everywhere you’re ever going to go.”
Aurora by Kim Stanley Robinson
Birthdate to the World by Ursula K. LeGuin
Six Wakes by Mur Lafferty. A ship traveling between the stars is the ultimate locked room mystery.
Miscellanea
With current technology, we could possibly build one that could reach the nearest stars within 80 years or so – a single human lifetime.