Discoverer 23Thor DM-21 Agena-B United States Air Force Launch Status Success Sat ยท Apr 8th, 1961 2:21 PM EST Location Space Launch Complex 1E Vandenberg AFB, CA, USA 83 launches have been at this location. Rocket Thor DM-21 Agena-B Length: meters Diameter: meters First Launched: January 18, 2021 Thor-Agena was a series of orbital launch vehicles. The Thor DM-21 Agena-B rocket has been launched a total of 17 times with 11 successful and 6 failed launches. Agency United States Air Force Type: Government Abbreviation: USAF Administration: Founded: Launchers: Spacecraft: Country: USA View Rocket Launch Schedule