The new Class, consisting of 13 spaceships, was developed specifically for scientific investigations and research in unknown areas of the Galaxy. Diverse scientific laboratories were located in the saucer section which turned the Enterprise into a mobile research platform. In spite of this, the heavy cruiser was well-armed, as it and its crew of 430 people were alone way outside the Federation space during the missions - and in addition, as part of the United Federation of Planets, they were obliged to protect its sphere of influence against aggressors.
During the 5-year mission starting in 2265 under the command of Captain James T. Kirk and First Officer Spock from the planet Vulcan, the Enterprise therefore "explored strange new worlds", seeking out "new life and new civilizations", and boldly going "where no man has gone before". During this time they made many initial contacts, some involving armed conflict with alien species.