Interstellar Probes

[Jovus]

We either invent FTL and get there faster than any conventional probes could, or civilization collapses before any such probe is in position to transmit data anyway.

At least, that's my prediction.

[1of6Billion]

Any Interstellar probe will definitely be a New Horizons style mission. Zip by and take as much data as possible.

[More Boosters]

On 01.12.2015 21:18:43, fairytalefox said:

The only more or less plausible way to communicate with the probe I can think of is to manipulate the star's light. A planet-size mirror, or a cloud of vapor, something like that. My point is, we have to either use an existing extremely powerful source of radiation or create our own one.

Yes, it's far beyond our current or near future technologies, just like the probe itself.

Or maybe we can just refuel the probe and return it back home. Somehow. ISRU or whatnot.

Not that we can be sure or that it is likely but as far as we know there are no planets in the star systems close to us so we'd bet on small moons with ISRU-usable stuff.

Edited December 8, 2015 by More Boosters

[wumpus]

Getting the probe to Alpha Centauri is pretty straightforward: aim it there and wait.  Use an ion engine and keep firing prograde until free of Earth, then free of the Sun (and pointed to Alpha Centauri).  Difficulty: you probably want to replace the Xeon with Argon (they are both noble gasses to avoid fouling the system, but Argon is more common than CO2, while Xeon is unbelievably rare.  Unfortunately Argon will make your engine much less efficient, but you can bring along plenty of "fuel".  Second difficulty: you will likely want something other than the Pu isotope currently used it space, the half-life won't get you that far out of the solar system.  You will also likely want another [low power] RTG with a long-lived isotope for communication along the way and possibly getting there.

Slowing down is the kicker.  You can either flyby way faster than New Horizons ever did (well, you are flying through an entire solar system, but at relativistic speeds) or spend nearly half the trip slowing down.  My guess is that this just isn't an option.  The reason is that you have to start so you have roughly equal burns accelerating and decelerating,  and designing a RTG with multi-century lifespan isn't going to happen (by the time solar works, you already left the system).

Six year latency (three each way) means that you can pretty take as much time as you like to encode your signals.  Current tech (ignoring the "last for centuries" requirement) should be able to hit Shannon levels (the mathematically ideal levels) of error correcting codes given that the time it takes to compute them isn't an issue.  On the other hand, that latency means that all your assumptions had better be right (locating Sol, aiming the laser or whatnot at it and blasting the message away) had better work as even with centuries to wait you only get a fixed number of communications/responses.

Don't ask me about "last for centuries in 3K and vacuum".  I'd like to say that in interstellar space there won't be the nasty radiation, but if you want to get there at all you will be bombarded by particles traveling at [your] relativistic speed (this might mean that you have to do the [nearly impossible] slowdown manuever or have more "Alpha Cent wind" [see solar wind] than you can handle [at .1C].  This might be nearly impossible, but presumably *somebody* knows something about how most of the things [semiconductors, NTR parts [the isotopes are straightforward, but the other stuff?] and robotics [may all the gods help you with the servos].

This all assumes that *somebody* will remain in contact with it for 400 years.  Presumably, that means that using 400 year old technology wouldn't be a problem (I've hammered a rail road tie in a blacksmith demo myself, as long as the tech keeps getting used it isn't a problem).  While it seems weird that you would have to maintain a 400 year old protocol with 400 year old algorithms, don't be surprised if there are bits and pieces of TCP/IP 1.x still lying around then.