Leave things alone and pretty soon Earth will have real space travel.
We have no plans for space travel - at the moment.
During the 1950s, space travel became a reality for the first time in history.
But the section on space travel was three million years old.
They asked if any of those nations had space travel.
What we have developed is a form of space travel.
You can figure who that would be, and what use they'd make of space travel!
Technology has come forward enough to allow things such as the internet, space travel and television.
Space travel was right for the culture we knew - or maybe it wasn't.
Ten years from now, commercial space travel will be a reality.