The Venture was presumed lost in 2192, only a few years before the rest of the Daedalus class ships were withdrawn from active service. However, she had not been destroyed, and instead had been swept into deep space by an intense subspace storm. The Venture returned to Federation space in 2205, having made first contact with the Medusans, and acquired thousands of terraquads of data on previously-uncharted areas.
First contact with the Medusans had unfortunately robbed the Venture's executive officer of his sanity, but over the course of their interaction, the ship's chief medical officer, Dr. Herman Brandt developed a type of visor that made communication with the noncorporeal beings safe. (USS Venture Sourcebook)