When we think of space exploration, many of us think about interstellar travel.  That’s travel from one star to another.  The logical choice for a first try would be to send a manned probe to the Alpha Centauri system, or to Proxima Centauri, since these are the closest stars to ours.  After all, Proxima Centauri is only 4.24 light years from the sun, and when you’re used to dealing with distances in the millions of light years, 4.24 sounds doable.  It sounds easy.

NOAA image, Alpha Centauri

Let’s stop a minute and think about that.  We’re currently at the stage of sending unmanned probes into space for interplanetary exploration, and if we were to continue with it, we might be ready to send a manned probe to Mars in a few years.  We know that we are approaching the level where that will be possible, so why not interstellar travel?

First off, because of the distance to be covered, a manned interstellar craft would have to be generational.  That means that YOU won’t make it to the next star, but your descendants (born on the trip) might get there.  We’re no where near capable of traveling at, or close to, the speed of light.  Just the fuel needed to make the trip is unbelievable.  In fact, at our current technology (even projecting a bit into the future), it would take 100 times the energy output of the entire planet to fuel a voyage to Proxima Centauri.  We just don’t have the resources available on this planet.  But let’s pretend we’ve discovered a great, new source of energy which allows us to make the trip, plus maintain life on the ship, plus lets us slow down as we reach our target.  Are we getting there?

No.  Look at Voyager I for a minute; it’s currently traveling the fastest of any space craft out there, and it wouldn’t even reach Proxima Centauri for another 72,000 years.  Granted, we could do better than Voyager now, with our current technology; but not so you would really notice a difference.  If we could build a generational ship capable of making the trip (and manage to solve the other myriad physical, social, and psychological problems), think of how many generations it would take to make the trip.  With that much time in space, and the unfortunately restricted gene pool, would we even recognize what would eventually crawl off that ship?  Let’s face it; that would cause some definite speciation… and speciation is the process by which new species are formed.  You can’t argue with that; it’s just the way it works.

Many scientists now believe that we will be forever restricted to our own solar system.  That interstellar travel will be forever beyond our reach.  Somehow, I don’t think so.  The entire history of our species has been spent beating our heads aggressively against brick walls.  I think we’ll get there some day.  Our species never has known when to quit.  If we stopped picking at a problem just because it was “impossible”, we’d still be floating around in the primordial ooze.

We’ll get there.

I'm sorry, I couldn't resist. This reminds me so much of Homo sapiens