The Case for Human Space Exploration

               It may surprise you to learn that Neil deGrasse Tyson, one of Earth’s most prominent advocates for extraterrestrial exploration, would be very glad to inform you of the myriad ways the universe is out to kill us all.  He has special knowledge of the many dangers that would face final-frontier explorers, yet he still wants them to go exploring.  What do he and the many other advocates of manned space exploration see in such endeavors?  Nothing short of the survival of our species.

               Homo sapiens sapiens (that means you) are currently rated an “LC” for “Least Concern” as regards to our conservation status.  Though it is true that our population’s rapid escalation makes us not too vulnerable compared to the rest of the species on our planet, there are plenty of events that could turn that state of affairs on its head.

               Our extinction could quite possibly be nigh, and the causes could be many.  Starting from the very tiny, a super-effective virus or bacterial disease could come along and make short work of contaminating all of us in today’s interconnected world.  On a larger scale, there are still enough nuclear weapons to destroy every human on the planet many times over.  Without proper mitigation, the greenhouse effect could go into runaway mode, boiling the oceans right off the face of the planet.  These extinction possibilities start and end at Earth, but we are also threatened from elsewhere.

               A large meteoroid could plunge into the depths of our Earth, ending us and many other species the way one did the dinosaurs.  A nearby (as in within our galaxy) supernova could bathe us all in its gamma radiation, causing mostly death.  It could be that there is extraterrestrial intelligence, and we get to find out when they bring their superior technologies to take our planet’s resources for their own use, leaving us dead or dying.

               I know what you’re thinking.  This sort of thing is never going to happen to me!  It is true that the probability for human extinction occurring during our lifetime via any of these methods is relatively low.  But just because it probably won’t happen to you doesn’t mean that you get to not care about it or do nothing to act against such processes.  This is the reason we (some of us, at least) attempt to mitigate our impact on the environment.  How would do we feel if that we inherited a planet on an exponential path of environmental destruction?  I could go on and on with that subject, and think I will in a later post.  The point here is basically moot, because even though the extinction methods I’ve laid out so far are possible, but not too likely, I can give you one that is both unstoppable and definite: the death throes of our sun.

               The sun is an ordinary star.  In fact, it is of the type which astronomers classify as “main sequence” stars, because that is mainly the type of stars that are.  The only thing that makes it special to us is that it is the star about which our planet revolves, and the source of energy for (most of) life on Earth.  We have been able to observe other stars in the universe just like our sun at various stages of their existence.  In gas nebulae, we see stars being born, starting to turn their hydrogen into helium.  Elsewhere, we see the aftermath of the event that will certainly be the end of any life remaining on Earth.

               When a star runs out of hydrogen to turn into helium (which is what has made the sun shine since its birth), it begins to turn into a red giant star, so named because of the color of light produced by new types of reactions within, and the dramatic increase of size.  How dramatic?  How about large enough to engulf the orbits of Mercury, Venus, and Earth.  Our planet is destined to eventually be inside the sun.  Life as we know it cannot survive on this planet forever.  What are we going to do?

               This, I think, sufficiently describes why we should venture out into space.  It’s as if we live in a house at the bottom of a valley scheduled to be flooded by the installation of the dam.  If we want to survive, we will leave that place behind and live somewhere else.  The survival of the human race and all other terrestrial life depends on colonizing out into space.  Luckily, we do have time on our side for this eventuality.  The sun won’t begin turning into a red giant star for a few more billion years.  With that time scale, the previously mentioned methods of destruction are more of a threat.

               Let’s tackle the really tough question: why should we worry about this now?  If we have billions of years to get out of here, why would we ever want to invest our resources in getting off-planet today?  Couldn’t we just wait until somebody invents faster-than-light travel and save ourselves the trouble?  This is the argument refuted famously (or maybe not so) by Andrew Kennedy’s Wait Calculation.  There is a time certain when given the constants of distance to destination and average overall growth in travel velocity, that one would not be passed by people who started out later in faster vehicles.  For an interstellar journey, the calculation comes up with this perfect time for getting to Barnard’s Star in about another millennia.

               Perhaps it is not time to begin work on interstellar travel quite yet, but when we do start, we should have a great leg-up from where we stand now.  That’s because the time to start on interplanetary travel is now.  Humans have been to the moon, and our devices have been flung to every planet and ex-planet in our solar system, and beyond.  We face a frontier.  Humans have never set foot on another planet, and we do not currently have the technology to survive such a voyage, let alone allow for a return trip.  There are a few private companies with ambitions to explore this frontier, but historically, the most successful exploration has stemmed from governing agencies’ initiatives.

               NASA has an annual budget of under $18 billion, which is under 0.5% of the federal budget.  It has been estimated that the discounted rate of return for all of NASA’s activities in its first 10 years was over 33% by its 30^th.  NASA put up arbitrary goal posts to mark progress, like sending men to the moon.  Though the economic impact of the boots actually hitting lunar dirt is nominal, the repercussions of all the new technologies that enabled such a feat are still driving economies today.  With all the new and different challenges posed by a manned mission to Mars (and back), a similarly incredible return on investment would occur today.

               The current problem is that NASA has not been pushing the frontier of human space exploration.  The challenge to figure out a way to survive long interplanetary trips has not been faced, and none of those new technologies or their byproducts have been invented yet.  And each day, we draw closer to our inevitable extinction on this planet.

               Sure, in the long run, these past few decades of not pushing the human space exploration frontier will be but a blip on the timeline, hopefully overpowered by the great activities that came before and will come after.  But as long as our species’ extinction could occur at any moment with the flip of a launch switch and a misunderstanding, it would behoove us to not have all our eggs in one basket.

               Our chance of survival as a species goes up with each new place we make home.  Nuclear winter would devastate Earth, but barring some extreme measures, Mars would go unscathed.  Spreading our footprint across the solar system acts as a sort of insurance against events that could wipe out all life at any of our homes.  The sun turning into a red giant and eventually fizzling out, however, might not be survivable within this solar system.  For that, we would have to spread out to other star systems.  Hopefully we will have a plan by then.

               All of these measures are in the interest of our species’ ultimate survival.  But are we worth it?  Should we boldly go where no one has gone before, so that generations to follow can do the same?  If we set out to colonize the entire galaxy, are we noble for allowing our children’s children a shot at life, or are we parasitic for making use of the resources we find along the way?  If we ever got to the point of having a human presence orbiting every star in the galaxy, it will be so far in the future that we probably won’t even be the same species.  We will have evolved into something different, potentially many different species.  Regardless, I think that there is much reason to pursue survival.  I believe that it is our purpose.

               In the Universe, so far as we can tell, the absence of life as we know it is the norm.  Even on our planet, throughout its roughly 4.5 billion year tenure, multicellular life has been around for just over 25% of that time.  Our species has only been in existence for only 200,000 years, or about 0.0044% of Earth’s age.  Intelligent life is not the rule, but the exception.  Newton’s second law of thermodynamics states that in a closed system, there can never be an increase of order.  That is to say that things will either stay the same or become more chaotic, unless there is an addition of energy from outside.  In the case of us, our complex physical, psychological, and cultural systems are the products of ever-increasing order.  Earth is life’s system.  Earth gets energy from the sun day and night, allowing for life to thrive and become more and more complex.  We have essentially taken energy from the sun, and transformed it into the human-ruled world we have today.  Our very being is the (allowable) exception to this fundamental law of the Universe.

               In the extreme long-run, considering the Universe as a whole as one closed system, current theories postulate the eventual heat-death of the Universe.  Eventually, there will not be enough matter to fuel stellar formation.  Eventually the last stars will die out, and the Universe will consist of nothing but stellar remnants, diffuse gasses, and radiation.  If this is the ultimate fate of the Universe, then life is a blip of insolence within this trend.

               In much of the Universe, we see this trend of ever-increasing chaos.  But in our corner, here on Earth, the mechanics of the Universe have been just so to allow the exact opposite.  We are the Universe in defiance of itself; a pinnacle of order in the sea of chaos.  It has taken us this long to arrive at this point, and our fate depends on ourselves.  Let’s make the most of it while it lasts, and make this thing called life last for as long as we can.  Let’s go exploring!