Inter-stellar travel

Since the administration is setting aside manned space flight for now, maybe we should set our sights on something bigger and longer term. What would it take to send a probe to a planet in another solar system and receive data back from it? Astronomers have discovered all these extra-solar planets and it seems like mankind should really send something off to one.

If space exploration is being done for human knowledge and all mankind, why not send off an interstellar probe that would visit another solar system EVEN IF the journey spans 3 to 5 human generations. People don't forget things that happened generations ago. So how 'bout planting a seed that will yield a quantum leap in human knowledge 100-150 years from now?

There was one idea that perhaps a near-term achievable interstellar probe could use a very small probe accelerated to high velocity with a light sail or magnetohydrodynamic ion sail. Dunno enough to judge feasibility.

The launch power would come from massive solar power stations at about the orbit of Mercury. The solar power stations would drive enormous lasers which would track the out-going probe for months or years constantly accelerating it out of the system. That way the probe wouldn't need onboard reaction mass or propulsive power, and could be accelerated to a pretty decent velocity.

Unless robotics gets awfully dern fancy, that plan would imply at least a few folks out there mining asteroids and building massive solar-powered laser stations. A pretty far-fetched task for a nation that soon can't even afford to shuttle astronauts to low earth orbit;