A lot of people believe a space ship crossing the vastness of space is impossible, at least for man. The distance is too great for space travel, e.g. (the Voyager spacecraft traveling as fast as it does crossed the heliopause on September 12/13 and reached out to interstellar space). To reach the nearest star it will take 70,000 years. Not very encouraging for any of us waiting.
Let me put that into perspective.
SPACE THE FINAL FRONTIER
There was a time when man could not cross the oceans of the world. Man didn't even even know there was another side. If he threw a bottle in the water on one shore, it would take years to reach the other side, if it ever made it. He would have no way of knowing as it floated with the currents, if it caught one to hold onto, and didn't get eaten or broken along the way.
Someone eventually made a craft, that could withstand the raging seas, protecting him. It's debatable who that person was, but they may have been paddling a big canoe like craft, with oars and it may have taken months but they paddled on, eventually making it to the other side.
A few centuries later someone invented the sailboat, making it even easier, taking less time, now one month.
Then, someone invented a boat they called a liner and the time got less and less. A week to cross. A floating hotel.
The plane was invented. Then the jet. The Concorde. A few hours.
Now, the space station crosses the Atlantic Ocean in only 12 minutes. Imagine that!
Space travel may seem impossible today, just like it did when the first person crossed the oceans so many years ago in that oversized canoe with a paddle. The feat might have seemed like science fiction until it was conquered.
In my opinion; of course space travel will be possible in the future. Hopefully it doesn't take centuries to make that crossing into the great vastness of unknowns called; space, to a solitary planet a billion billion miles away.
We won't be around when they do.