Back to the Future
Most of us may remember a movie by this same title. In fact there were several "Back to the Future" sequels. In the movie starring Michael J. Fox and Claudia Wells, after traveling back in time, they found that the only way to return to the future was to recreate the system and follow the same principles that led to the successful journey in the first place. One of their greatest challenges was recreating the speed and momentum needed for time travel.