A Thor-Agena launch vehicle, ready to launch the Discoverer 37 (KH-3) spacecraft, on 13 January 1962

Thor-Agena was a series of orbital launch vehicles. The rockets used the Douglas-built Thor first stage and the Lockheed-built Agena second stages. They are thus cousins of the more-famous Thor-Deltas, which founded the Delta rocket family. The first attempted launch of a Thor-Agena was in January 1959. The first successful launch was on 28 February 1959, launching Discoverer 1. It was the first two-stage rocket to place a satellite into orbit.


Among other uses, the clandestine CORONA program used Thor-Agenas from June 1959 until January 1968 to launch United States military reconnaissance satellites operated by the CIA. During this program, Thor-Agena launch vehicles were used in 145 launch attempts [1] now known to have been part of satellite surveillance programs.

Also, Alouette 1, Canada's first satellite, was launched on a Thor-Agena-B.


  • 16 launches between 21 January 1959 and 13 September 1960.
  • The Discoverer 14 satellite used in the CORONA spy satellite program was launched by a Thor-Agena-A. On 19 August 1960 usable photographic film from the satellite was recovered by a Fairchild C-119 Flying Boxcar recovery aircraft. This was the first successful recovery of film from an orbiting satellite and the first mid-air recovery of an object returning from Earth orbit.[2]
  • First successful launch: 12 November 1960 with Discoverer 17.
  • Last launch: 15 May 1966 with Nimbus 2.
  • First launch: 28 June 1962.
  • Last launch: 17 January 1968.


  1. ^ Day, Dwayne; Logsdon, John; Latell, Brian (1998). Eye in the Sky: The Story of the Corona Spy Satellites. Smithsonian Institution Press. pp. 236–245. OCLC 36783934.
  2. ^ "Discoverer-14 1960-010A". NASA. 14 May 2020. Retrieved 6 January 2021. This article incorporates text from this source, which is in the public domain.