Star Trek: 10 Starships That Went Missing

6. USS Valiant

Though it wasn't the first sister-ship of the USS Defiant, the USS Valiant was unique among its class. As a Starfleet Academy training vessel, it was several steps up from the old Constitution-II class USS Republic. Crewed by Red Squad, the elite group of cadets, and a handful of commissioned officers, it took off out into the galaxy - just as the Dominion War broke out.

In the first week, the ship found itself caught behind enemy lines. As with so many other ships in the fleet, it was classed as missing. Starfleet simply didn't have the resources to commit to a rescue mission. 

The ship may have been lost, but it was far from lost in space. The newly-minted field officers, led by Captain Tim Waters, conducted deep space reconnaissance, eventually discovering the dreaded Jem'hadar Battleship. Twice the size of a Galaxy-class ship and three times as powerful, this new warship would prove deadly to Federation forces.

The Valiant undertook an ill-advised mission to attack this ship. It was a death sentence for all but one of the crew and its two guests. The Valiant and most of her escape pods were destroyed by the Dominion ship, bringing her tale to a tragic yet avoidable end.