Sending Humanity to the Stars?

From an article in the Daily Galaxy , I was reading about a theme that runs through science fiction - sending humanity to the stars.  Of course once you let this cat out of the bag, you find that there are more questions than answers and all of them good.  But really there are the three most important and therefor the most troubling.  Where would you send humanity to first, exactly what would you send and the multi-pronged question how long would it take.

First to save space you can't send people.  DNA and self replicating robots would keep the payload fairly small.  But most of the job to build more machinery to grow and nurture the new life falls on robotics much more advanced than we have today.  So where would you send humanities's "ark"?   The Daily Galaxy article really drops back to basics in it's choice, to the target that was always the darling child destination when I was younger and that was Alpha Centauri our nearest stellar neighbor is only four light-years distant.  Alpha Centauri A is the same type of star as our Sun and may well have planets in the habitable zone.

But the "closeness" is relative.  With the present engine tech it would take our "seed ship" 80,000 years to arrive at the Centauri system.  Even with some of the promising technology for thrust such as the ion drive, it will still take a vast amount of time to move even to, for all intents and purposes, next door.

arrow in pic at top of page, shows the Centauri a system

read the complete Daily Galaxy article