The Pioneer class was a Federation starship class, a tier 1 utility cruiser/frigate in Starfleet service in the mid-23rd century. The USS Pioneer was the prototype of the Pioneer-class and designed to undertake missions usually carried out by larger vessels but for shorter durations due to the frigate's limited crew complement and size. Still, the Pioneer and its sister ships were often found on the Klingon and Romulan frontlines. Ships of this class were smaller than a Constitution-class heavy cruiser. Tier 1 ships required for a commanding officer to be ranked lieutenant or higher. (STO video game: Agents of Yesterday)