My goal is to generate a plausible means of interstellar travel without using FTL technology while supporting round trip travel time to nearby stars within a human lifespan (measured by the life of the humans left on earth).
At present, I'm contemplating a multi-stage process:
- Beginning with a probe of small mass, accelerated at a reasonable fraction of 1g, possibly using a solar sail and laser propulsion.
- Once around the target solar system (having slowed in transit sufficiently to orbit the target star), it has independent capabilities to locate and navigate to small asteroids, harvest resources, and manufacturer devices of modest size.
- Communicating with earth, the probe will employ designs arriving from earth to create tools/machines larger and more capable than itself, bootstrapping a manufacturing hub. Those machines will use the probe as an intermediary or communicate with earth directly.
- Once an environment/insulated biome/space station has been created that can support human life, the probe or another machine will accept patterns for human consciousness. The premise here is that, while most of the human body can be replicated without requiring the greatest accuracy, the component of the human brain that maintains consciousness must be replicated in exacting detail (to the extent that copying the pattern destroys the original) to maintain a semblance of identity.
This strategy avoids the challenge of attempting to corral and transmit the specification of an entire human (which in some estimates would require over 10^40 bits*). The fiction here is that we can efficiently extract and compress the pattern of an individual by looking at only a few ounces of brain matter distributed through the frontal lobe and cerebral cortex. The remaining brain can be copied at a much lower resolution while the body can be generated by off-the-rack plans. The other half of this fiction is that it is infeasible to create that spark of human consciousness using the same off-the-rack process used to create the body -- identity in the story would change radically without this stipulation.
In order to fulfill the 2nd half of this fiction, there would have to be some sort of no-cloning aspect to the technology (entanglement?). Otherwise, you'd be able to create an army of the same individual at the target site.
What sorts of challenges haven't I considered in this future world? Where are the plausibility issues?
The "Messenger Line" comes from the practice of using a light weight string from bows to reach between ships, dragging increasingly heavy rope to support the transfer of cargo.
I suspect that the heavy lifting of communication would be done from earth and that the transmission power of a probe that made it to Barnard's Star would be limited. Also, having a single, small probe capable of navigating around a solar system with a chance of sensing small asteroids sounds unrealistic. Perhaps a swarm of a thousand or a million probes whose paths are scatter shot around the system stands a more reasonable chance of sensing an asteroid of suitable composition.
Does this premise already exist in science fiction?
*[see Teleportation: will it ever be a possibility @ the Guardian]