Space 14: A Quick Trip to the Technology Gift Shop
(continued from here; yes I did a bit of georgelucasing; original of that last post was way too long, sorry)
Technology Requirements/Assumptions
Given that we won't have Warp Drive/etc, what are we actually going to need/have in order to be able to get places? Or, rather, what's the best we're going to be able to do, sticking to known or at-least-vaguely-likely physics? Are we completely screwed when it comes to getting out to the stars, or is there a way to make it work? I think there is, but it's not going to be pretty, and we have to think big.
Let's start with my wish list, which I'll admit is still a bit ridiculous. To some extent it's really more of a best case scenario and it's also biased towards making the calculations easier (cf. all of the places where I'll be assuming 100% or near-100% efficiency).
To be sure, trying to predict where technology is actually going to be, say, a thousand years from now is at best risky; we have no idea when the next thousand-year dark age is going to set us back (I remain appalled that Archimedes came within a hair's breadth of inventing calculus, that Ptolemy pretty much did invent Fourier series, that the 2nd century Romans really were on the verge of industrialization, that if it weren't for the 3rd century collapse, we might have had all sorts of things 1500 years earlier).
On the other hand, these aren't predictions so much as stuff we're going to need eventually and we'll get it whenever we get it. Unless we truly are screwed.
But, at least, everything on this list is (IMHO) way more plausible than what everybody assumes we're going to have that I was complaining about before:
- Antimatter fuel cell: Picture your basic fuel cell: hydrogen and oxygen combine, but peaceably, so that instead of getting blown up we generate electricity (or heat, or light, or something else we need).
Now imagine the same thing with matter and antimatter, with minimal extra mechanism/mass so as to boost the overall efficiency as high as we can. No, I have no clue how to make this work. But if you want near-total conversion of mass into energy, this is clearly the way to go. Everything we'll ever do that comes under the heading of Energy Storage will be striving towards something like this. And there really ought to be a way to make it work. It's no less absurd than getting fusion power to work.
Note carefully that this is merely storage; once you use up all of the antimatter - at which point the cell will only have a very small fraction of its original mass, SF writers and stage directors please take note - you have to send it somewhere to get recharged, e.g., using
- Solar power satellites done right: Pretty much every power generation method we have is solar power plus some number of levels of indirection - yes, even fusion power, because that's just trying to do solar power without using gravity, which is a really stupid way to do solar power - so let's just cut out all of the middlemen. Make something with a big-ass collection panel that can survive being in close to the sun, have it suck up energy and split out some antimatter. Put a whole lot of them into an orbit shuttling between the solar corona and, say, behind Mercury, where there'll be this handy charging station where people can drop their empty cells off.
To put some actual numbers on this, if we have the satellites grazing the sun (1 million km out), that gives us 2kg/km² of energy (i.e., 1kg of matter and 1kg of antimatter for every square kilometer of panel) generated on each flyby, the orbit taking 30 days. Meaning if we can actually do a square kilometer of solar panel (sure, why not?), and then we make one to two million of these (they'll be about 17km apart at the top end of the orbit, so there's plenty of room for this) that's one arriving at Mercury with 2kg of energy every 2 seconds for a total production of 86,400 kg/day. And there are lots more orbits available if we need them (this is all trivial compared with what the Dyson Sphere folks want to do).
But remember this number because it's essentially our income. We'll get back to this when it comes time to talk about expenses.
And, in case anyone was wondering, a typical 21st-century human civilization stuck on a single planet - judging from our sample size of 1 - seems get by on about 15 to 20 kg/day (which is really a hell of a lot when you think about it).
Note that setting up this energy-capture infrastructure will be the first order of business for any exploration probe reaching a new star system.
- Best possible rocket/directed-energy-weapon: We've discussed this before. Big-ass laser sends out a beam of light/microwaves/whatever that can be entirely focused onto a small target thousands (or millions?) of kilometers away. If we want to be totally eco-friendly, we'll even pick a frequency that's completely harmless to wildlife and humans lacking dental work who might be getting in the way, all while still providing a 200% kick to anything with the right metallic coating, including the
- Best possible solar sail/reflector: Extremely lightweight, totally reflective, micrometeoroid-tolerant, blah-blah-blah. There will be some engineering tradeoff to determine the size (i.e., the smaller we make it the more accurate the rocket/laser thing has to be, and the more energy density it has to withstand, but the less vulnerable it'll be), which I'll leave the engineers to figure out.
Yes, we're going to need a bit of materials science magic for this. I'm sure 1000 years of research will come up with something useful.
- Better software:
We always want better software. I suspect there will ultimately be a whole lot of software issues.
But, presumably, if we can imagine building a self-driving car (hahahaha), building a self-driving star-system explorer, something that can show up in a new system, survey everything that matters, build energy and asteroid mining infrastructure, identify viable terraforming candidates and get to work on them, and make a few copies of itself to send to other systems,… that should be child's play.
In fact, I suspect this will be subject to far fewer safety regulations than self-driving cars will be, since, assuming we can at least forbid any of the descendant probes heading towards Earth, we'll know for certain that there won't be any humans in its path.
At least, initially.
(and now we finally go places)
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