Traveling through space is really difficult. Traveling to another star is damned near impossible, at least with our current technology.
It is unlikely that we will ever travel between stars at a speed faster than that of light. The speed of light in a vacuum is tops, and we aren't going any faster, ever.
Not that people haven’t given any thought to getting round this. NASA is said to be working on a warp drive that does strange things with space, but I can’t help wondering whether the forces required to warp space would not be so great that they would tear human bodies apart. Anyway, don’t dig me up to let me know they succeeded.
So if we are going to travel in space, we are going to do it at speeds slower than light. This presents many problems.
The best way to travel a long distance through space is to accelerate until you are halfway there, then decelerate for the second half. But the human body is not designed to operate at much more than one times the force of gravity (1g) on Earth’s surface so that pretty much dictates how fast you can accelerate and how long it will take you to get to another star. Of course, there is a maximum speed to which you can accelerate, if there is time for you to reach that speed (that is, if the journey is long enough). With current technology, this speed is not very high.
So it takes a long time to reach another star. And that means, you are going to be bored. Very, very bored. Even the most aggressive experiments on isolation have not locked people in a small tin can for more than a few months. Don’t think you are going to have a gym, a holodeck and a bar like Star Trek’s USS Enterprise. You’ve seen the pictures from the space station; barely standing room in any direction. You’re going to live in something like that for years. And if you don’t like the other members of the crew, it’s going to be tough to get away from them; the ship is going to get like Sartre’s dismal play ‘In Camera’.
And if you are thinking of returning to tell the family what it was like, you can forget that altogether. They’ll all be dead. It may take a long time for you to reach a star and return, but it is a lot longer on Earth. Your great-great-grandchildren may listen to you with feigned interest, but more likely, they’ll laugh at your taste in clothes and your inability to master the simplest of electronic devices. Historians aren't going to be interested for long because the time you left has been well documented. You might be able to do a weekend as a ‘living book’ at your local library.
So the trip to another star will almost certainly be a one-way trip.
And such a trip will be mind-buggeringly expensive. Too expensive for a nation. Too expensive for an entire planet.
Unless there is the incentive to mount such a trip. Nothing is too expensive if the incentive is great enough. Some have made the argument that there is no incentive, but there is always an incentive. Mankind is like that, we always find an excuse, a justification. It’s one of the first things we learn as a child and we never give up. And we've been there before. I won’t pretend that crossing the
Atlantic or sailing round the
world for a few years is the same as going to another star, but it does show
that people are prepared to leave their homes in search of something that
And the incentives would make (and probably have; When Worlds Collide, Canticle for Leibowitz, Contact) for great stories.
So, here are some good reasons to either go to another star, or send someone to another star, reasons that would justify the vast expense of building, crewing and launching an interstellar spaceship
1. Get rid of some criminals, terrorists or other undesirables. Of course, you will have to do this at regular intervals new generations produce new miscreants. A penal planet isn't an original idea. More interesting is, who is the undesirable, the one who goes or the one who stays?
2. Get rid of a disease by sending all people with the disease on the trip. The story of course, is that one person on the ship doesn’t have the disease. Or maybe, one person with the disease is left behind.
3. It might be an investment with a long-term benefit if (and it’s a big if) those on the trip send back something. Knowledge is probably the most lucrative return for such a trip. Goods would have to be expensive and light, services (for example, from the famous merchant banks of Alpha Centauri) seem a little far-fetched. The problem with this of course is that nobody invests expecting a return that far in the future. The investment would have to be Earth’s investment. Perhaps we need the knowledge to survive.
4. The trip could be funded by a religious group who want to take all their people to a new planet, either in an act of disgust with the old planet or, in search of their god, their prophet or whatever. Probably people outside the religious group would also invest in this trip, just to get rid of the ‘Holy Wullies’.
On a less serious note, it might be worth the expense just to get rid of annoying and useless people, as the Golgafrincham's did with their population in Douglas Adam's 'Restaurant at the end of the Universe'.
5. The population is reduced to an acceptable level. Such an evacuation would require a huge number of people on the trip, or many trips. Over time, it would probably require both. Eugenics without the genocide, but unless the travelers go voluntarily, probably not morally superior.
6. Discoveries and advances made while developing the interstellar ship will provide worthwhile benefits for people left on Earth. This seems the most likely option. The spin-off benefits from incremental advances in the design of the interstellar ship. However, I challenge you to make a good story from this.
7. The race is stagnating and dying. A new venture is needed to rejuvenate the species. This seems unlikely. It shows a degree of concern for future generations, that the human race has yet to muster, and certainly needs to show today, with our environment careening downhill rapidly.
8. Interstellar travel gets a lot cheaper. There are currently many initiatives under way to make spaceflight cheaper. There always will be. Perhaps someday, even the cost of interstellar flight will be brought down to a reasonable level. However, there’s probably not much of a story in documenting engineering advances that reduce costs.
Each one of these possibilities gives scope for many stories, but I’m sure there must be more. Perhaps even incentives that we can’t imagine at our current levels of society and technology.