The Nova class is a Space Marine lance boat, much like the Firestorm Class Frigate in the Imperial Navy. It is a much more controversial ship however, because it does not follow the Codex Astartes. It is a pure-breed warship, it can not land troops, or transport them to other ships. It is ineffective in planetry assault also, but it is a very apt capital ship hunter. Both the Imperial Navy and Inquisition have taken issue with the class, as it encrotches on the duties of the Imperial Navy, and upsets the balance of power within the Imperium, giving too much to the Adeptus Astartes. Due to this, the Nova remains a rare sight in the fleets of the Space Marines.
It is armed with a single lance in the prow of the ship, and two small weapons batterys, just as the Firestorm does. However, its engines are much more powerful, making the Nova almost twice as fast as a cruiser of the Imperial navy. This speed and manoverability allow the Nova class to get to favourable firing positions, deliver the lance armaments bite, and withdraw before the enemy can react to bring thier guns to bare on the Nova.
The Space Marines do not name their squadrons, therefore there are no famous ones.