Discoverer 23Thor DM-21 Agena-BUnited States Air Force Launch Status Success Sat ยท Apr 8th, 1961 2:21 PM EST LocationSpace Launch Complex 1EVandenberg AFB, CA, USA83 rockets have launched from Vandenberg AFB, CA, USA. RocketThor DM-21 Agena-BThor-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. AgencyUnited States Air ForceType: Government Abbreviation: USAFCountry: USA View Rocket Launch Schedule