Star Trek: 10 Starships That Went Missing

5. USS Hera

At the time it was reported missing, the USS Hera was commanded by Captain Siliva La Forge. Its disappearance became connected with the loss of a second starship, the USS Raman. While engaged in a rescue mission for the latter in the atmosphere of Marijne VII, Geordi La Forge believed he had discovered his mother - 300 light years from her last known location.

Though his hopes of finding his mother were soon dashed, one of La Forge's theories was, in essence, correct. The Hera's chief engineer experimented with the warp coils on this Nebula-class ship. La Forge believed that the trionic initiators in those coils created a subspace funnel, displacing the ship. According to David A. McIntee's novel Indistinguisable From Magic, the Hera fell into a natural quantum slipstream, emerging in deep space. 

In 2383. the Challenger, under the command of then-Captain Geordi La Forge, discovered the ship with survivors. According to Star Trek Online, it was finally destroyed in 2409 by Orion Pirates.