Atlas (missile)

B-65/SM-65/CGM-16/HGM-16 Atlas

Launch of Mercury-Atlas 2 in February 1961
Function	Intercontinental Ballistic Missile (ICBM)
Manufacturer	Convair
Country of origin	United States
Size
Height	75 ft 10 in (23.11 m) 85 ft 6 in (26.06 m) in ICBM configuration
Diameter	10 ft (3.0 m)
Width	16 ft (4.9 m)
Mass	260,000 lb (117,900 kg)
Stages	1½
Associated rockets
Family	Atlas
Launch history
Status	Retired April 1965
Total launches	24
Successes	13
Failures	11
First flight	June 6, 1957
Last flight	August 24, 1959
Boosters
No. boosters	1
Engines	2
Thrust	300,000 lbf (1,300 kN) Atlas D
Total thrust	360,000 lbf (1,600 kN) Atlas D
Fuel	RP-1/LOX
First stage
Engines	1
Thrust	60,000 lbf (270 kN) Atlas D
Fuel	RP-1/LOX

The SM-65 Atlas was the first operational intercontinental ballistic missile (ICBM) developed by the United States, and the first member of the Atlas rocket family. It was built for the U.S. Air Force by Convair Division of General Dynamics at the Kearny Mesa assembly plant north of San Diego, California. Atlas became operational as an ICBM in October 1959 and was used as a first stage for satellite launch vehicles for half a century. The Atlas missile's warhead was over 100 times more powerful than the bomb dropped over Nagasaki in 1945.

An initial development contract was given to Consolidated Vultee Aircraft (Convair) on 16 January 1951 for what was then called MX-1593, but at a relatively low priority. The 1953 testing of the first dry fuel H-bomb in the Soviet Union led to the project being dramatically accelerated. The initial design completed by Convair in 1953 was larger than the missile that eventually entered service. Estimated warhead weight was lowered from 8,000 lb (3,630 kg) to 3,000 lb (1,360 kg) based on highly favorable U.S. nuclear warhead tests in early 1954, and on 14 May 1954 the Atlas program was formally given the highest national priority. A major development and test contract was awarded to Convair on 14 January 1955 for a 10-foot (3 m) diameter missile to weigh about 250,000 lb (113,400 kg). Atlas development was tightly controlled by the Air Force's Western Development Division, WDD, later part of the Air Force Ballistic Missile Division. Contracts for warhead, guidance and propulsion were handled separately by WDD. The first successful flight of a highly instrumented Atlas missile to full range occurred 28 November 1958. Atlas ICBMs were deployed operationally from 31 October 1959 to 12 April 1965.

On 18 December 1958, the launch of Atlas 10B sent the missile into orbit around the Earth (without use of an upper stage) carrying the "SCORE" (Signal Communications by Orbiting Relay Equipment) communications payload. Atlas 10B/SCORE, at 8,750 lb (3,970 kg) was the heaviest man-made object then in orbit, the first voice relay satellite, and the first man-made object in space easily visible to the naked eye due to the large, mirror-polished stainless steel tank. This was the first flight in what would be a long career for the Atlas as a satellite launcher. Many retired Atlas ICBMs would be used as launch vehicles, most with an added spin-stabilized solid rocket motor upper stage for polar orbit military payloads. Even before its military use ended in 1965, Atlas had placed four Project Mercury astronauts in orbit and was becoming the foundation for a family of successful space launch vehicles, most notably Atlas Agena and Atlas Centaur.