In Part I of this essay, I lamented the fact that humans haven't ventured beyond Earth orbit, and our permanent presence in space amounts to only a handful of people at a time. Will humans ever colonize space on a large scale?
Space is a harsh environment, which means that any permanent colonies must have a very good reason for existing. Let's look at the possible reasons for having people in space -- through our old friends Greed, Fear, and Conviction.
Greed
This is potentially the most powerful draw. If there's money to be made, or some other practical benefit to be had, people will go immense distances and put up with horrible conditions. What can be gained in space? Well, everything in the Universe is either energy, matter, or information.
Energy: Space enthusiasts have been dreaming about pulling energy from the skies since the 1920s. German rocket pioneer Hermann Oberth imagined using a giant orbital mirror to light cities and croplands, even warming northern tracts to lengthen the growing season. In the 1970s, visionaries like Peter Glaser devised the solar "powersat": giant solar generators, as big as Manhattan Island, floating in geosynchronous orbit.
The big problem with generating power in space is getting it down to Earth where people want to use it. You can't really run a power cable to orbit -- at least, not unless you're willing to build a space elevator, which increases the whole cost of the project to literally astronomical levels. So powersat designers came up with the idea of using microwave beams to transmit power down to the surface.
And that's the sticky bit. Any device which can deliver large quantities of energy at a distance can be used as a weapon, which gives the whole powersat project major political implications -- would the United States be comfortable if China had giant microwave beam emitters overhead? Would China be comfortable if the U.S. had them? Would anyone be comfortable if North Korea had them?
There's also the environmental objection. Irrational opposition to nuclear power plants has prevented any new plants from being built in the U.S. for thirty years. Imagine how the same activists would react to the idea of shooting beams of microwaves from space. (And to be fair, the receiving stations would be large, not very pretty, and unusable for any other purpose.) I'm afraid the combination of political and environmental hurdles are likely to keep powersats a strictly theoretical concept for decades to come.
Matter: This is an old staple of science fiction -- mining colonies on the Moon, asteroids, or other worlds. In fiction, they're often depicted as the California Gold Rush with spacesuits. Crusty lone prospectors cruise the asteroid belt looking for rich lodes, heartless mining companies oppress the workers in the mines of Io, and conditions are always ripe for a conflict.
And it's true, there is a lot of raw material floating around in space. The question is, would it be worth going up there to get any of it? Because as it happens, there's a large celestial body rich in minerals right here -- the Earth. We're standing (or sitting) atop a giant ball of metal and silicon compounds, oozing with carbon compounds. So for any substance, looking for it off-Earth has to be cheaper and easier than getting it on Earth. And given the expense of launching people into space and keeping them alive, that means space resources must be things which are simply unavailable on Earth.
As it happens, there is one substance which may fit that description: Helium-3. It's an isotope of helium which could potentially fuel nuclear fusion powerplants. You fuse a helium-3 atom and a deuterium atom to get helium-4 and a proton plus energy, or you fuse two helium-3 atoms and get a helium-4, two protons, and more energy. Helium itself is quite rare on Earth (the only deposits of any commercial viability are in the gas fields of northern Texas), and only a tiny proportion of that helium is He-3. Helium-3 can also be produced from tritium (an isotope of hydrogen)
However: the Sun gives off helium-3, and particles of it stream outward with the solar wind. The surface of airless bodies like the Moon capture stray helium atoms (though again, in tiny proportions). Meanwhile, out past Mars the giant planets are composed almost entirely of hydrogen and helium. "Scoopships" could skim helium from their upper atmospheres, and carry it to processors which would extract the helium-3.
Could helium-3 be the "gold" for a Gold Rush model of space colonization? Possibly -- it depends on whether making He-3 from tritium on Earth is more expensive or unsafe than scooping it from Saturn's cloud tops.
Information: Right now, nearly all human activity in space is concerned with the collecting of information. Unless something like helium mining becomes common, space will remain the preserve of scientists. Which brings us right back to the question of whether humans or robots do a better job.
But there's another form of information-gathering: tourism. Space tourism has been the Holy Grail of private launch operations for several years now. The reasoning is that if millions of people each year spend thousands of dollars to go on ocean cruises, maybe thousands of people will pay millions of dollars to vacation in space. So far a handful of people have actually done it: if you have $30 million to spare, the Russian Space Agency will happily launch you on a joyride to the International Space Station. Private space lines like Virgin Galactic are hoping to bring down the cost by increasing traffic, putting it in the range of the merely rich, rather than the super-rich.
Right now space tourism is the only form of commercial-based human space exploration which has shown any viability, but it's also the most modest in scope. Most space tourism operations envision orbital flights only -- possibly to a private space station hotel for extended visits. Nobody's talking about vacations on Mars.
In Part III we will look at Fear and Conviction as motives for space colonization, and postulate some futures.
Recent Comments