SM-65D Atlas

Atlas D (SM-65D)

Launch sequence of an Atlas D ICBM test, April 22, 1960
Function	ICBM Expendable launch system
Manufacturer	Convair
Country of origin	United States
Launch history
Status	Retired
Launch sites	LC-11, 12, 13 & 14, CCAFS LC-576, VAFB
Total launches	135
Successes	103
Failures	32
First flight	April 14, 1959
Last flight	November 7, 1967

The SM-65D Atlas, or Atlas D, was the first operational version of the U.S. Atlas missile. Atlas D was first used as an intercontinental ballistic missile (ICBM) to deliver a nuclear weapon payload on a suborbital trajectory. It was later developed as a launch vehicle to carry a payload to low Earth orbit on its own, and later to geosynchronous orbit, to the Moon, Venus, or Mars with the Agena or Centaur upper stage.

Atlas D was launched from Cape Canaveral Air Force Station, at Launch Complexes 11, 12, 13 and 14, and Vandenberg Air Force Base at Launch Complex 576.

The fully operational D-series Atlas was similar to the R&D model Atlas B and C, but incorporated a number of design changes implemented as a result of lessons learned during test flights. In addition, the D-series had the full-up Rocketdyne MA-2 propulsion system with 360,000 pounds of thrust versus the 275,000 pounds of thrust in the Atlas B/C's engines. The B and C series had a common pump assembly feeding both booster engines, but the Atlas D had separate pumps on each engine, both still driven by a common gas generator. Operational Atlas D missiles retained radio ground guidance aside from a few R&D launches which tested the inertial guidance system designed for the Atlas E/F, and the Atlas D would be the basis for most space launcher variants of Atlas.