I'm thinking speculatively. NASA is doing experiment with ion thrust tech. Assuming, that inside the next 5 years, we could create a probe which would take on the order of 30 to 50 years to reach Alpha Centauri: What problems would it have?
ie: Is the biggest challenge going to be communications back to Earth? Maybe a small probe can't transmit a strong enough signal (especially since we'd be essentially looking straight at the star, from our point of view) ?
Or Maybe the challenge in transmitting is really the targetting, to keep the Antenna pinpointed on Earth?
Or would there be problems with powering the probe over a 50 year journey (at which point we'd really want it to have several years left of usable lifetime) ?
Or is there problems with space probes, outgassing or other gradual losses which would cause the device to decay after 50 years of vaccum?
Do the long-lasting Voyager probes help answer any of these issues? I know they are MUCH closer to earth than what I'm talking about, but at least they are still alive and transmitting...
This is a speculative question, so I hope it is allowed by the forum rules. I'd like to think about how such problems can be overcome -- but first I really need to know what the problems might be. So I'm looking for thoughts or info...
EDIT: perhaps I was optimistic. if a 50 yrs travel time is not practical, even with a long duration thrust like ion drive, then feel free to posit a longer flight time.