If movies are to be believed, NASA interstellar flight capability is just around the corner. Unfortunately, the reality of the situation is a bit different. Most people seem to vastly underestimate the incredible distances between the stars, and for NASA to traverse these distances will require either remarkably advanced propulsion technologies or new ways of thinking about exploration.
Interstellar distances are so vast as the virtually beggar the imagination. The distance to the nearest star – Alpha Centauri – is over 25 trillion miles. That’s trillion with a T. And that’s just the nearest one.
At this moment, the fastest vehicles human beings have ever built are the Voyager unmanned spacecraft. These are traveling out of our solar system at 38,000 miles an hour.
But even if Voyager was traveling in the direction of Alpha Centauri – which it isn’t – it would take Voyager thousands of years to traverse the distance. So clearly, conventional rockets aren’t going to get the job done.