What would it take to fly a piloted starship at near-light speeds a hundred years from now? NASA and DARPA are engaged in a study to see what technologies might be needed and how far they have to go to be mature enough. NASA Ames' Pete Worden, a guy always ready to think out on the edge, is one of the movers in this effort.
COMMENT: Sure, it's still going to be speculative. And sure, there are countless nearer-term concerns. But someone needs to think about the long term and the interstellar situation we could someday become.