Traveling through time is easy. You are doing it right now sitting in your chair. Controlling how you travel through time takes more effort and some planning.
Every ten years, New Horizons travels 1/2 second backwards in time.
Faster Than Light travel (FTL) will be time travel. If FTL travel is not possible, mankind will be locked into this solar system forever. Unable to escape, our only option will be to send out our machines and artificial womb ships into the void.
Creating a machine to purposefully travel through time would create interesting and unique opportunities for traveling through space. Such a machine would need a unified field theory and machine intelligence beyond what is available.
Such a machine would enable the creation of time-dilated laboratories. Food and energy for entire planets could be produced in minutes. Mutiple life long scientific experiments could be done in a day.
Learn more about how we will get there on our Machine Intelligence page.