Launch of a Delta D with Intelsat I
FunctionExpendable launch system
Country of originUnited States
Launch history
Launch sitesCape Canaveral LC-17
Total launches2
First flight19 August 1964
Last flight6 April 1965

The Delta D, Thrust Augmented Delta or Thor-Delta D was an American expendable launch system used to launch two communications satellites in 1964 and 1965. It was derived from the Delta C, and was a member of the Delta family of rockets.

The three-stage core vehicle was essentially the same as the Delta C. The first stage was a Thor missile in the DSV-2A configuration, and the second stage was the Delta-D, which was derived from the earlier Delta-A. An Altair-2 SRM was used as a third stage. The main difference between the Delta C and Delta D was the presence of three Castor-1 solid rocket boosters, clustered around the first stage.

Both Delta D launches were conducted from Cape Canaveral Air Force Station Launch Complex 17A. The first, on 19 August 1964, carried Syncom 3, the first satellite in a geostationary orbit. The last, on 6 April 1965, carried the first commercial communications satellite, Intelsat I. [1][2]


  1. ^ Wade, Mark. "Delta". Archived from the original on 2008-07-24.
  2. ^ Krebs, Gunter. "Thor Family". Gunter's Space Page. Archived from the original on 2007-08-06. Retrieved 2021-12-21.