In 2286, while patrolling Sector 5, Neutral Zone, the Saratoga encountered a probe of unknown origin on a direct course to Earth. As the crew attempted to make contact, however, the ship was neutralized by the probe, the transmissions of which were being carried on an amplification wave of enormous power, impacting on all ship's systems. The ship's power was subsequently restored when the probe left Earth. (Star Trek IV: The Voyage Home)
The Saratoga was a reuse of the USS Reliant studio model built for Star Trek II: The Wrath of Khan, relabeled with a new registry. In the first edition of the Star Trek Encyclopedia, the Saratoga was identified as having either the registry number NCC-1937 on page 289 or NCC-1867 in the ship list on page 321. In subsequent editions, the registry in the ship list was changed to NCC-1937. On page 334 of the second volume of the fourth edition, the registry for this ship in the ship list had been changed to its correct registry. Yet, the registry in the main entry, in the same book on page 250, was still given as NCC-1937.
The bridge of the Saratoga was the reuse of the Grissom bridge from Star Trek III: The Search for Spock, which was in fact a reuse of the Enterprise bridge. (The bridge of the Reliant was also a reuse of the bridge of the Enterprise.)
It may be reasonable to assume that the Neutral Zone that the Saratoga was patrolling was the one shared with the Klingon Empire, as it is noted by Cartwright that the probe had traveled in or near Klingon territory.
The Saratoga was notable in Star Trek history as it was the first Starfleet ship to appear on screen with a female captain. That captain was played by Madge Sinclair, who went on to play another captain, Silva La Forge, appearing in TNG: "Interface" as the captain of the USS Hera.
According to the novelization of Star Trek IV, the Saratoga and her crew are rescued shortly after the probe's departure; although the ship has been immobilized for the longest time (having encountered the probe first), her captain had managed to save herself and her crew by placing them in suspended animation.
The FASA role-playing game listed the same vessel with the registry NCC-1720, but most data from the game conflicts with filmed sources. The heavy cruiser Saratoga was also mentioned in a novel, The Kobayashi Maru.
The non-canonical Ships of Starfleet lists this USS Saratoga as a Cyane-class heavy frigate with the registry NCC-1892.