It's obviously a one way trip, no one would expect to return home (at least, not to the same home that they left, in 2000 years, human civilization may not even exist when they return, they could return to a planet colonized by Apes... hey, they would make a great movie!).

But one-way trips have been proposed for planetary colonization as well, and there are a lot of people that would be willing to make that trip.