We could state that the only function of space is to be filled. Space colonization is ultimately the only way to proceed, but still there are some that object to the idea.
The permanent autonomous (self-sufficient) human habitation of locations outside Earth, would be an insurance against a global calamity, from a devastating war to the occurrence of a deadly plague, the collapse of the ecosphere or a deadly asteroid impact to name just a few. Our blue planet is indeed a fragile home and as technology advances and the human population grows chances increase that a global catastrophe will strike humanity as it has struck other species before. We should aim to escape being replaced as the dominant species or even becoming the last.
Space colonization has been fully achieved only in science fiction. Most people will think of space colonies as being on the Moon or Mars while others will advocate that colonies will first be built in orbit, and envision huge space stations as depicted in the literature and movies.
The location of colonization can be:
- On a planet, natural satellite, or asteroid
- In orbit around the Earth, Sun, Lagrangian point or other object
Or even a mix of the two. Humanity may find a way to transport a colony-sized population of men and women to another world, but the issue remains that each one of those people requires an amazing amount of supplies, that we here on Earth take for granted. Human space flight can be seen as prohibitively expensive, and much can be accomplished by automation and remote presence.
The issue of location and the different ways to proceed is a frequent point of contention between space colonization advocates. The way to go about colonizing outer-space has been researched and many ideas have been put forward, especially by science fiction authors, some may not even include the displacement of population from one location to another, but may consist only on a permanent remote presence, or in remotely creating "life" in situ.
Some argue that moving beyond the solar system is totally impractical in any reasonable time scale. Even so there are plans being created for that eventuality. But that should not be the primary objective, ultimately our species will be forced to do so, if not for any other reason than that our Earth and Sun have an expiration date.
The anti-space arguments have gone so far as to suggest that space colonization is a remnant of historical colonization - it is (the idea at least) a lingering desire left over from the conquest of territory on earth. Indeed most of the ideas put forward have a logical connection to the human history regarding the colonization of new lands, with the added technological limitations and advances that a new endeavor would bring today.
Some also argue that space exploration wins the hearts and minds of voters but does little else, but in fact since the Space race during the cold war this notion does not seem to stand. It could be said that the objective of colonizing space adds fuel to the patriotic dogma of conquest, and thus reinforces negative national prejudice rather than helping to unify earth and so, the pragmatic argument to 'live together on the earth we have' is a powerful one, suggesting that if even half the money of space exploration were spent for terrestrial betterment, there would be greater good for a greater number of people, at least in the short term. But should one proposition exclude the other ?
As an alternative for the future of the human race, many science fiction writers have instead focused on the realm of the 'inner-space', that is the (computer aided) exploration of the human mind and human consciousness. Perhaps one example of this trend is the popular movie The Matrix, where all the action takes place on (under the surface of) Earth, and in a computer generated reality in cyberspace. However, this form of exploration need not be exclusive to space colonization, as exemplified by Transhumanist philosophies.
Robotics and tele-presence seems a good start for the process of colonizing space but sadly after Lunokhod 1 in 1970 and 1971 with Mars 2 and 3, only recently in 1997, did we get to do it again with the Mars Pathfinder, that successfully exceeded expectations. It seems strange that a successful strategy can be moth-balled for so long, even in the International Space Station (ISS) only in 2011 was Robonaut been given a chance. It then becomes clear that there is a general administrative (and political) problem regarding mission planning in the USA. The problem with space program stall in the USSR/Russia was mainly economic in nature (leading to a political collapse), as the economic situation and political stability improves we may still be surprised.
In 2001, the space news website SPACE.com asked Freeman Dyson, J. Richard Gott and Sid Goldstein for reasons why some humans should live in space. Their respective answers were: (from http://www.space.com/missionlaunches/colonize_why_011008-1.html)
- To Spread Life and Beautify throughout the Universe
- To Ensure the Survival of Our Species
- To Make Money
- Save the Environment
- Provide entertainment value in order to distract from immediate surroundings
Louis J. Halle, formerly of the United States Department of State, wrote in Foreign Affairs (Summer 1980) that the colonization of space will protect humanity in the event of global nuclear warfare. (see http://www.foreignaffairs.org/19800601faessay8146/louis-j-halle/a-hopeful-future-for-mankind.html)
The scientist Paul Davies also supports the view that if a planetary catastrophe threatens the survival of the human species on Earth, a self-sufficient colony could "reverse-colonize" the Earth and restore human civilization.
The author and journalist William E. Burrows and the biochemist Robert Shapiro proposed a private project, the Alliance to Rescue Civilization, with the goal of establishing an off-Earth backup of human civilization.
Perhaps the most powerful justification is that colonization is employed by every successful species and civilization. Obviously, species with large, diverse habitats are less prone to extinction than those in a single niche. The Earth is a tiny fraction of the solar system, and an even smaller part of the galaxy. If life were to colonize the entire solar system via a system of tens of thousands of orbital colonies, and then send generation ships to nearby stars, it would become effectively immortal. It has been noted that life has colonized every livable niche on Earth. It would be surprising if, having developed the ability to do so, life failed to colonize the solar system.
Control of the solar system's resources will provide immense power and wealth to those who grasp it. Power and wealth are well known, effective motivators.
Sadly in the current state of affairs it is with some reason that people start to give credibility to the notion that man has never gone to the moon. The Moon landing was in 1969 and since 1972 we (humans) have never gone beyond Earth's orbit. Most of the human population alive today, did not experience the occasion in the necessary context. This will assuredly be the end of the phrase "If they can put a man in the Moon why can't they...", since it is a fact that today we can not put a man on the moon. It would take a bit more than a decade to do it again. This and the fact that "they" (the Western governments) have lost much if not all of the reputation "they" had especially in the fields of management, applied science and economics, the most important fields on such endeavors.
Some people argue that there will not be ever again the same level of effort put behind human space presence like we saw in the Apollo program. That all that effort was the result of the Cold War. Even considering the antagonism of the time, these arguments do not make sense, since at the time the US was already involved in a war, 1950-1973 Vietnam War and no one, especially the US was expecting the collapse of the USSR. It is then necessary to consider other complementary motivations, beyond propaganda and projection of power, and look to the continued benefits from that technological event, that lead to the advancement of numerous technologies.
With the decline of the USA supremacy, we are witnessing a downgrading of NASA (and even ESA), it is to be expected that the agencies will only support low cost projects and robotic programs fill that bill. China, the rising power has yet to build a space station (it has one programmed, Tiangong) so it will take some time for it to be able to step in as a leader in the field, even if China has also declared an interest in establishing a constant human presence on the moon.
Japan also was working in some advanced concepts, but the recent decline in its economy and stability seems bound to relegate it to a supporting role, much like Russia that lacks the political vision to see space as a viable investment beyond being a commercial orbital supplier, that holds much of the facilities, experience and know how that many others lack.
In the West this new reality puts the cards in the hands of the private enterprise, that seems to be only now taking form, even if at an accelerated pace. It is yet to be seen if they will pull anything more complex than the space tourism concept out of the bag. But the fact remains that private enterprise will not be able or willing to advance the space frontier, due to the risks involved and the higher costs of doing research and development in untested fields where unforeseen problems in development are typical. We can hope that space agencies and corporations will make improvements in already understood processes. Especially, they should adopt state of the art technology and quickly adapt to change. That was always a problem to monolithic government enterprises like NASA. This is reflected extremely well in the history of the Space Shuttle program. One lesson taken from the shuttle program may have been the need for in the future to include decision points to go along with programs that depend upon a number of untested techniques. Then progress is less likely chained to sub-optimum techniques because a commitment was made to them when a large program was undertaken as a whole.
The main problem with space exploration, that the USSR came to realize, especially after the USA won the race to put a human on the moon, was that there was no special benefit in the action itself, and that the further away from Earth the more costly it becomes. That is why the USSR has centered on and invested in establishing long human presence in near Earth orbit (holding that record). Note that the USSR was the first nation to put a satellite in orbit, a camera on the moon and to return to Earth the first piece of extraterrestrial soil. It did also extremely well in pioneering the exploration of other planets like Mars and Venus. It would be interesting to know what nations have spent more in space exploration so far.
The solution then seems to point to going out in small incremental steps.