While I don't have a degree in astronautical engineering and my knowledge of physics is just enough to explain Einstein to a ten-year old child, I believe I have figured out the mode of transportation that would bring the first astronauts to an extrasolar body like Pandora, setting of James Cameron's sci-fi movie Avatar. No, I'm not boldly predicting we're going somewhere beyond lunar orbit. I'm merely making a projection, using the lens of today's technology, to paint a picture of what I believe to be our most likely future should we manage to survive as a true spacefaring species, and not as some throwback to the Stone Age or slave of the Matrix.
I base my techno-scenario mostly on what I call the ''laziness principle''. The technology with the best chance to succeed is that which requires the least energy to produce a given amount of work. This is why we don't have flying cars, at least here on this gravity well we call Earth. We haven't yet discovered a law of anti-gravity that will allow us to park a car in the air. There are, of course, glaring exceptions to the laziness principle. A conventional chemical rocket, for example, ''works'' harder than a plane but is so far our only ticket to outer space. But this dependence on "hard-working" technology has come about only because none of the rival technologies, such as the space elevator, have gone beyond the prototype stage. The day a ten-ton satellite is pulled up rather than launched into orbit is the day that rockets become extinct as the primary means of getting off the planet.
Spaceships, once they escape a planet's gravity, appear to follow the laziness principle. However, accelerating a spacecraft and then decelerating it to speeds meaningful for interstellar travel still requires some serious investment in energy, unless the goal is to drift in space. As should be obvious from the phase-out of the Space Shuttle in favor of a capsule-based system, building a less massive spaceship helps reduce both the cost of production and the fuel for propulsion. A seeder ship bearing only embryos or DNA samples would require a fraction of the fuel needed to send a generation starship, such as the Battlestar Galactica, to its destination.
Unfortunately, the distance to the next star system can easily turn a microgram into a deadweight. In a partly speculative essay, hard sci-fi writer Charles Stross calculates the "explosive" energy budget for a single astronaut on a hypothetical trip to Proxima Centauri, comparing it to the "yield of the entire US Minuteman III ICBM force". He uses this lesson on the economics of interstellar travel to call into question any human attempt to populate the Galaxy.
Even with Moore's Law growth of personal wealth, interstellar travel appears destined to be the ultimate luxury, exclusive to Tom or Tara Trillionaire, CEO of GooSoft, the materials, genetics, biofuel, quantum computing and everything else company. Then, after blowing a fortune or the Fortune 500 on the launch infrastructure, our supernova rich exo-plorer will have to contend with the cruel reality of being a lonely astronaut for the rest of his or her life. Cue for end theme, Space Oddity, as hybrid plasma-ion rocket undocks from GooSoft orbital station.
But what if we could travel not just lighter but as light, and therefore as fast, as light itself? What if instead of launching rockets, capsules or hollowed asteroids, we could beam our astronauts to their destination?
Instead of a spaceship transporting them to the next star system, imagine sending our crew of intrepid explorers via the fastest known delivery method available, as a beam of electromagnetic radiation. Sounds familiar to a Trekkie? Ah, but the problem with the transporter is that it violates the laziness principle. Beaming, Star Trek-style, calls for nothing less than the reversal and re-reversal of Einstein's famous equation, the total conversion of matter into energy and back into something not resembling a butcher's workshop. So why go through all the trouble of de-materializing then re-materializing flesh, blood and bone (not to mention the sexy spandex) when all that matters is the stuff between the ears?
In the distant past humans could only communicate by direct sensory stimulation. Holler at me, wave the fig leaves at me, or scratch me behind the ear. And then our ancestors learned to paint pretty pictures or carve them into wood or bone. Passed on to a messenger, perhaps a rider on horseback or a marathon runner, these magical shards of the soul made long-distance, time-shifted communication possible.
Time-leap to the present. If we want a document delivered fast, we don't go to the nearest DHL or Fedex office. We turn on the computer and fire off an email. If our recipient wants a hard copy of the love letter, she can laserprint it at her place (if not, well, she can drag it to the "trash can"). All this at a fraction of the cost and the carbon footprint of a door-to-door delivery.
Time-leap to the future. Instead of writing down, typing or tapping our sweet nothings into the screen of our iPuter(tm), we do the lazy thing. We lie back and jack in for a direct mind link. Sorry, honey, I can't touch you today. My teledildonics suit is borken.
Time-leap to the far future. Forget about the hassles of hibernating or exercising. All you need to make that long haul flight to Alpha Centauri is an ultraband laser beam; a brain wave reader; and an Nth generation 3D printer that can print living tissue and not just plastic. Somewhere in the Sol system, you and your group of literally "armchair" astronauts gather for a brain scanning session. The collected data is verified, compressed, and then beamed, perhaps using some quantum encoding algorithm, at the target star. Years and light years away, a space station, sent out decades or even centuries in advance, receives the transmission, prints out replacement bodies, and programs into them the minds of the crew, who "arrive" feeling as fresh as new-born babies.
Beaming a person's consciousness could be the cybernetic equivalent of email. Yes, the system calls for giant leaps in storage, processing and interface technologies, but mere hops compared to those needed to conjure up a warp drive. I'm way more hopeful of the engineers of the future perfecting the technology to upload, store, and download consciousness than any relativistic propulsion system or, even more fantastical, a faster-than-light hyperdrive system. There are already studies and experiments that demonstrate the feasibility of direct mind-to-machine interfaces, say, by translating brain waves into linguistic data. We can compare these crude, first-generation interfaces to the first electronic computers of the 1940s that have less processing power and less storage than a cheap programmable calculator today.
Given that we're in sci-fi mode already, what then if some genius manages to perfect a warp drive? That might change the physics but not the economics of the picture. It will still be cheaper to transmit data (no, I'm not referring to the Star Trek android) than transport warm bodies from star A to star B. If for some reason we can't warp the stream of data, we can always warp the thumb drive containing a "burnt" copy of it.
Of course, placing the receiving stations or hubs into orbit around the target star will still be monstrously expensive. But done correctly, this mother of all public works projects will be a one-shot (or at most two-shot, if one desires a back-up) expense, analogous to the work that must be done to enable transcontinental communication.
But, you might ask, does this exercise in high speculation have any practical point besides being the germ for a non-existent sci-fi novel?
I believe that sci-fi, even the B-movie ones, have a great influence on the development of technology. Sci-fi doesn't predict. It makes the future. If we extend the definition of sci-fi to those quaint or queer tomorrow's world documentaries that brought us the flying car and canonball rides to the Moon and continue to bring us robot nannies and butlers, then we realize how powerful the Pavlovian effect these visions have on us and, perhaps more significantly, on our children.
Buck Rogers, Captain Kirk, and maybe even Luke Skywalker brought us the Space Shuttle (and even renamed one, the sub-orbital demo unit, the Enterprise). Star Wars shaped the debate, if not the idea, about the Strategic Defense Initiative, President Ronald Reagan's still-born missile shield system. Asimov and mecha anime gave birth to Asimo and the Aibo. From the flickering screen of green terminals, William Gibson created cyberspace and condemned us to Facebook and virtual farming.
I used to belong to the "space probes suck" school of space advocates who think robotic probes are a poor substitute for landing a "real" shovel-and-pickax explorer on the surface of another planet. Not anymore. Now I think space probes are our path to the stars. As they become more sophisticated, the time will come when we can equip them not just to explore but to build in situ, converting surrounding resources into the raw materials for other machines or even synthetic organisms no different from their genetic donors.
While good and perhaps even essential for recruiting new space advocates, spaceship and especially starship science fiction have been a very bad influence on the development of space technology. Typically mixing both crew and supplies, starships are largely self-contained islands in space. The Space Shuttle reflects this mentality of having a one-size-fits-all vehicle, when for most purposes a mission is better served by launching separate spacecraft, specialized for carrying crew, cargo, and extra propellant if needed. But how underwhelmingly unromantic the Apollo capsule is compared to the Millenium Falcon! You call that overgrown barrel a spaceship? Any spaceship worthy of the name should be able to take off and land, if not under its own power, then at least under captain's control, not the calculations of some bureaucrat in mission control!
How do I see the distant future of space travel? For junkets to Titan and Europa, fast fusion rockets might be the way to go. But for voyages to Betelgeuse and Gliese 581, I'd rather wait for our Von Neumann armies to lay down the galactic tracks. Fly me to the Moon, but please fax me to Pandora.