Star Trek Lower Decks s3 Teaser - Promo Trailer HD - STAR TREK: LOWER DECKS focuses on the support crew serving on one of Starfleet's least important ships, the U.S.S. Cerritos. Ensigns Mariner, Boimler, Rutherford and Tendi have to keep up with their duties and their social lives, often while the ship is being rocked by a multitude of sci-fi anomalies.