The Thor DSV-2U or Thor LV-2F Star-37XE Star-37S-ISS was an American expendable launch system used to launch five DMSP weather satellites between 1976 and 1980. It was a member of the Thor family of rockets, and a derivative of the Thor DSV-2. The first stage was a Thor missile in the DM-19 configuration. A was used as the second stage, and the third stage was a Star-37S-ISS. All five launches were conducted from Space Launch Complex 10W at the Vandenberg Air Force Base. The final launch on July 15, 1980 (UTC) of a DMSP 5D satellite failed.