Star Trek: Voyager: Season 5, Episode 6

5 - 6: Timeless

Voyager uses new quantum slipstream technology in an attempt to return home, but a miscalculation by Kim causes the ship to crash into an ice planet. Fifteen years later, the sole survivors, Chakotay and Kim, have resigned from Starfleet and attempt to alter history to save the ship from disaster before Starfleet can stop them. They steal the Delta Flyer to send a message back in time and avert the catastrophe. However, Captain Geordi LaForge is determined to stop them at all costs.