The Constitution-class starships, which were also known as Starship-class1 or Class I Heavy Cruisers, were the premier front-line Starfleet vessels of the United Federation of Planets during the war.. They were designed for long duration missions with minimal outside support and are best known for their celebrated missions of galactic exploration and diplomacy which typically lasted up to five years.The original configuration and refit variants of this class influenced starship design significantly, and accelerated the standardization of the fleet.
Celebrated members of the class included the USS Enterprise and the USS Enterprise-A—two of the most venerated starships in Federation history, having risen to prominence under the captaincy of James T. Kirk.
The largest and most elaborate vessel class Starfleet had yet fielded, with an unprecedented fourteen research labs each, ships of the Constitution-class became the most extensive mobile research platforms ever deployed by the Federation, and were responsible for expanding known space by thousands of cubic parsecs. The class utilized a greater level of modularity, which allowed for incremental changes to configuration -- so flexible that it became standard starship design practice. As other classes began to employ such modularity, Fleet design became increasingly more uniform.