Whenever the idea of establishing a colony off-world comes to mind the first place many think of is Mars. Primarily this is due to Mars being the most similar of all the other planets to ours, having an atmosphere and land features that look very similar to some of our own. However that’s where the likeness ends as its lack of magnetic field has meant that its atmosphere has been stripped bar to a thin layer of carbon dioxide, taking all of the surface water along with it. Thus whilst it would seem like the best candidate for humans to establish themselves elsewhere in this solar system there are other potential sites that have distinct advantages over what Mars can provide.
One surprisingly good candidate for a potential human colony is Mercury. Now initially this would seem like a pretty bad idea as its surface temperatures regularly exceed several hundred degrees celsius and the only atmosphere to speak of is a tenuous layer is mostly made up of solar wind and vaporized surface material. However it’s close proximity to the sun gives it access to abundant solar power, orders of magnitude more than what is available on the surface of Mars. Considering that power is probably one of the biggest limiting factors for a colony and the size it can grow this advantage could prove invaluable, so long as the initial challenges could be overcome.
Probably the biggest thing that Mercury has going against it is the time it would take to get a mission there. Whilst we’ve got craft today capable of covering the distance in under 40 days or so its tight orbit around our sun makes it incredibly difficult to get into orbit with it. It’s not so much that it’s hard to do, more that the time typically required to transit to there with an approach that will get you into orbit takes on the order of years, not days. This would mean the development of systems to support humans for a sustained period in space which would open up other alternative locations for a human colony.
Interestingly such systems could be used to establish a colony on Venus, although not the type you’d think of. Whilst Venus’ surface is a hellish place where it rains metal it would be quite possible to create cloud cities that float around an area that’s much more hospitable to humans. Indeed the pressure at 50KM above the surface is the same as Earths and thanks to the dense, mostly carbon dioxide atmosphere a lifting gas that’s simply breathing air has a lifting power of 50 times that of helium on earth. The protections required then are far less strenuous than those required to get to Mercury initially and the dangers posed by the atmosphere are far less severe than that of a harsh vacuum.
Past these planets though are options start to get limited as whilst many moons of the gas giants of the outer solar system have an abundance of things like water or other useful materials they’re typically quite harsh environments, either being flooded with ionizing radiation or lacking any kind of atmosphere without the benefit of having high amounts of light to take advantage of. They’re essentially equivalent to space itself in that regard and whilst I love the idea of large human colonies in space there’s really no substitute for colonizing another planet.
For what its worth we’re likely going to see a Mars colony within our lifetimes, one that will likely be limited to a few one way pioneers or entrepreneurs looking to take advantage of the first new frontier in a century. The other options, whilst being only slightly more fantastical than that of a Mars colony, aren’t likely to happen any time soon as there needs to be much more ground broken in engineering terms before they become viable. Regardless of where it happens a human colony off our planet is fast becoming a necessity if we want to ensure the human race doesn’t have a single point of failure in our own planet.
Life on Earth evolved in a never ending battle to be the most well adapted species to its environment. Consequently it can be said that the life forms that evolved here on Earth are specialist biological machines with certain requirements that must be met in order for them to thrive. It then comes as no surprise that entire species can be wiped out by small changes to their environment as their specific adaptations no longer provide them the advantage that they require. However there’s one particular pressure that all life has evolved with that, at least for most life, will never change: gravity.
Many biological processes rely on gravity in order to function correctly and for the longest time it was thought that no life that evolved here on Earth could survive a zero/microgravity environment for long. Indeed medical doctors back on the Mercury program were very sure that the second their astronauts went into orbit their vision would blur, rendering them incapable of performing any tasks. The truth of the matter is whilst we’re designed to work well in our standard 1G environment our bodies can cope quite well with microgravity environments for extended periods of time, provided certain precautions are taken.
What’s truly fascinating to watch though is how other creatures function without the aide of a constant gravitic pull. Indeed quite a lot of science done aboard the International Space Station has been centred around studying these effects on varying levels of creatures and some have produced very interesting results. For example spiders sent up to the ISS don’t spin webs like their Earth bound relatives do, they instead weave what looks like a tangled mess all over their environment. It would seem that their sense of direction heavily relies on figuring out which was is down and absent that their webs lose their usual symmetry.
Other animal species seem to adapt rapidly to the loss of gravity’s unrelenting effects. Mummichogs, a type of small fish, appear to be quite hardy little creatures in microgravity environments. They suffer some initial confusion but after a short while they appear to be quite capable of swimming perfectly well in microgravity. Ants too seem to adapt rapidly to the loss of gravity with their nests taking on an almost surreal structure that is not like anything you’ll see on Earth. The habitat that NASA designed to take ants into space is also quite incredible being a clear blue gel that contains everything the ants need to survive both the trip up and life aboard the space station.
Incredibly some species appear to be better suited to microgravity than the regular 1G environment on Earth. C. Elegans, a type of unsegmented worm, not only adapted to life in space but showed a marked increase in life span over their earth bound cousins. The cause appears to be a down-regulation of certain genes associated with muscle ageing which in turn leads to a longer life. Whether the same genes could be down-regulated in humans is definitely an area for investigation but as everyone knows us humans are far more complicated beasts than the simple C. Elegan.
Indeed whilst muscle atrophy is one of the biggest problems facing astronauts who spend a long time in space there are several more concerns that also need to be addressed. Unlike the C. Elegan we humans have an internal skeleton and absent the effects of gravity it tends to deteriorate in much the same way as it does in bed ridden patients and people with osteoporosis. Additionally whilst the ISS is still within the protective magnetic field of Earth it’s still subject to much higher levels of radiation than what we get here on Earth which poses significant health risks over the long term. There’s also a whole swath of things that don’t quite work as intended (burping in microgravity is fraught with danger) which we’re still working on solutions for but suffice to say if we’re ever going to colonize space reproducing the effects of gravity is going to be one of the most critically required technologies.
It’s not often that we get the opportunity to effectively remove a unyielding constant and then study how much it influenced the development of life here on Earth. This is one of the reasons why space based research is so important, it gives us clues and insights into how dependent our biological processes are on certain key variables. Otherwise we’d figure that gravity was simply a requirement for life when now we know that life can survive, and even thrive, in its absence.
I don’t pretend to be all up on American politics, I look to much more intelligent people than I for understanding of those matters, but if there’s one thing that I know inside and out its space and the industry that surrounds it in the USA. As it’s campaign time now in the USA presidential hopefuls turn to high rhetoric and sweeping promises in order to win votes for their elections and the space program is not immune to this. Indeed it seems that NASA is most often used as a rhetorical tool that ends up under-delivering on its promises, mostly because those promises aren’t backed up with the appropriate funding.
Jumping back a presidency you can see why this was so, with George Bush’s vision for space exploration that had us returning to the moon by 2020. Instead of adding additional funding to complete those goals and all of those already set out for NASA much of the vision was funded out of cancelling other projects, like the Shuttle and their involvement with the International Space Station. What this resulted in was a program that was under-funded and ultimately impinged heavily on NASA’s ability to conduct many of their other core directives. The VSE was then replaced by the Obama administration which had a larger focus on building core space exploration infrastructure whilst out-sourcing rudimentary activities to the private sector, a much better direction for NASA to head in.
Newt Gingrich, current candidate for the Republican nomination, made some sweeping statements about how he’d reform NASA and see Bush’s original vision achieved. He would see a permanent moon base by 2020, a good chunk of NASA’s budget allocated for private incentives and a culling of some of the bureaucracy. They’re ambitious goals, especially considering that Bush made similar ones almost a decade prior that are no where close to being achieved. Still there are some good ideas contained within his vision, but a whole lot more that just show a total lack of understanding.
As always Neil deGrasse Tyson does a much better job of tearing it down than I ever could:
Neil hits on a point that I’ve long held true: NASA should be charged with advancing space frontiers and the private sector should be tasked with the things that are now routine. We’re already seeing that kind of industry develop what with companies like SpaceX gearing up to resupply the ISS with several others developing along the same lines. This is where the private industry does well but it does not do well in pushing the frontier forward. That’s an inherently risky venture, one that’s very unlikely to be undertaken by any private agency. Advancing the frontier is the realm of the government and NASA is the agency to do it.
Where I do agree with Newt though is the slimming down of the NASA bureaucracy. Much of the costs incurred by the Shuttle program was the standing army of people it had, not the actual launches themselves. The original plan of launching often, up to 50 missions per year, would have drastically reduced the impact this standing army had on the cost per launch of the Shuttle. With the cancellation of the shuttle program much of that will have already been cut but NASA is still quite a large agency. How that would be achieved is left as an exercise to the reader.
Extraordinary ideas require extraordinary amounts of support and whilst I’d love to believe that Gingrich would follow through with this idea I’ve seen how ideas like this have panned out in the past. Thankfully, with or without Gingrich’s interference, the private space industry is setting itself up as being a viable replacement for the rudimentary activities that NASA needs not bother themselves with any more. What I’d like to see now is Obama’s vision for NASA has changed since he cancelled constellation and whether or not he falls victim to the same high rhetoric trap of over-promising and then not support the vision.