Thor-Agena

A Thor-Agena launch vehicle, ready to launch the Discoverer 37 (KH-3) spacecraft, 13 January 1962
Function	Expendable launch system
Country of origin	United States
Size
Height	Thor-Agena A: 28 m (92 ft) Thor-Agena B: 31 m (102 ft) Thor-Agena D: 31 m (102 ft)
Diameter	2.44 m (8 ft 0 in)
Mass	Thor-Agena A: 53,130 kg (117,130 lb) Thor-Agena B: 56,507 kg (124,577 lb) Thor-Agena D: 56,507 kg (124,577 lb)
Stages	2
Launch history
Status	Retired
Launch sites	Vandenberg Air Force Base
Total launches	145
First flight	21 January 1959
Last flight	17 January 1968
[edit on Wikidata]

Thor-Agena was a series of orbital launch vehicles.^[1] The launch vehicles 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 launch vehicle to place a satellite into orbit.