The first stage was a
Thor missile in the
DSV-2A (MB-3-II) configuration, and the second stage was the
Delta D (
AJ-10-118D), which was derived from the earlier
Delta. The baseline Delta C used an
Altair-2 (X-258) 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. == Launches ==