The Nirvash Class Exploration Cruiser was a post Excelsior Design that was created to operated as an efficient and long ranged explorer, the design would prove extremely reliable. Featuring a number of upgraded phaser batteries, a large number of back-up systems, a secondary impulse engine for if/when the primary was either disabled or non functioning, a small emergency nacelle stored in pieces for those rare occasions when both nacelles were non-operable, and enough supplies for the ships small crew to conduct decade long missions. A Nirvash class Exp. Cruiser typically had a standard crew size of 150, though it could safely operate with twice that number or as little as 50. The USS Nirvash herself would conduct a number of exploration missions, the ship would conduct several decade long exploration/diplomatic missions deep into Tholian Space where it was under constant 'escort' by several Tholian warships at all times and where all discoveries were shared with the Tholians no matter how small said discoveries may have been. The Nirvash would end up being the one of few Federation vessel to make repeated trips into Tholian space and would be one of even fewer to leave Tholian space unharmed, it became the first ship to host a number of semi-permanent Tholian crew members during these voyages into Tholian space. During the Dominion War the USS Nirvash was deep in Tholian space and would not reemerge from Tholian space until 2381, where the crew discovered that they had missed out on an entire war. The Nirvash would continue its missions into Tholian Space for many years to come, though in 2385 the ship recieved a update to various systems and its arsenal. The USS Nirvash would set out for Tholian Space once in 2389 to resume its exploration of Tholian space in yet another decade long mission.

I was listening to this throughout the process of creating the USS Nirvash, https://www.youtube.com/watch?v=firyf8SCJWc