Lieutenant Commander Data was a Soong-type android, the first and only such being to ever enter Starfleet. Data was created some time in the 2330s and was killed in 2379, sacrificing himself to save the crew of the USS Enterprise-E. (TNG: "The Measure Of A Man", "Datalore", "Silicon Avatar", "Conundrum", "Inheritance"; Star Trek Generations; Star Trek Nemesis)