The first Delta C launches with Explorer 18
|Function||Expendable launch system|
|Country of origin||United States|
|Launch sites||Cape Canaveral LC-17|
|First flight||27 November 1963|
|Last flight||22 January 1969|
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. The baseline Delta C used an Altair-2 third stage, whilst the Delta C1 had an FW-4D third stage, which provided a higher payload capacity than the Altair. It is unclear whether two or three launches were made using the C1 configuration.