Transit - friznit/Unofficial-BDB-Wiki GitHub Wiki

Transit spacecraft were developed for updating the inertial navigation systems on board US Navy Polaris submarines. Most Transit satellites were launched with two or more piggyback payloads, such as Injun or Grab/Solrad/Poppy. Transit-O (Oscar) featured a SOOS dual payload adapter (Stacked Oscars On Scout) and remained operational until it was superseded by GPS.