Aries

Here are some images of my kit bash of the 1/1000 scale Hermes/Monoceros sub type U.S.S. Aries N.C.C. 602. Built from the Polar Lights 1/1000 scale TOS U.S.S. Enterprise kit.
From Memory Beta"
The Hermes-class was a type of Federation starship in service in the 23rd century, and is classified as a scout ship. (ST reference: Star Fleet Technical Manual)

Built on the Saladin-class hull, the Hermes-class was designed to be the electronic eyes and ears of the fleet, using its long-range sensors and scanners to search much farther than other ships could.

The large number of special sensors made this ship particularly effective on scientific missions, though these came at the cost of no torpedo armament and a reduced phaser suite.

(From the instruction manual for the video game Starfleet Command, itself taken from the original Star Fleet Battles source material).

These ships were eventually replaced by the more specialized Oberth-class science vessels for survey missions, and superceeded on long-range mapping cruises by more modern sensor technology embarked on standard starships.

Existing ships of the class were uprated beginning in 2271 to make use of new technology and capabilities that were developed for the uprated Constitution-class. This greatly increased the performance longevity of the class, carrying them into the 2300's.

The class was retired in the early part of the 24th century, but a handful of the vessels were uprated once again to face the threats of the Dominion and Borg in 2373 in a desperate move by the Federation to field numbers against the twin threats.