[exmarine]

Don't count on such space travel. Do you know what a speck of space dust will do to a spacecraft at extreme speeds, or thousands of specks (or larger pieces) over years? Star Trek is fiction. Such a spacecraft would be battered to pieces. Space is a dangerous place.

[RightWhale]

Such a spacecraft would be battered to pieces.

Space is kind of empty. But there are dust particles and very tenuous gases out there. Suppose a spaceship the size of the Space Shuttle were moving between the sun and Alpha Cent at, say 1/2 c so the trip would take 10 years. What are the odds it would make it all the way without hitting something that would turn it to instant debris? 1 in 10? 99 in 100?

[Junior]

I've seen conjecture on using an electromagnetic "screen" to deflect such particles from the path of vessels travelling at far slower speeds within the Solar System (~40 km per second). Such a system would probably work at near relativistic speeds...

[KevinDavis]

There are some dangers here on Earth also...