SM-65 Atlas

TheSM-65 Atlaswas the first operationalintercontinental ballistic missile(ICBM) developed by the United States and the first member of theAtlas rocket family.It was built for theU.S. Air Forceby theConvairDivision ofGeneral Dynamicsat an assembly plant located inKearny Mesa,San Diego.

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

Atlas 2E missile, San Diego Aerospace Museum
Function	Intercontinental Ballistic Missile(ICBM)
Manufacturer	Convair/General Dynamics
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
Success(es)	13
Failure(s)	11
First flight	11 June 1957
Last flight	24 August 1959
Boosters
No. boosters	1
Powered by	2
Maximum thrust	300,000 lbf (1,300 kN) Atlas D
Total thrust	360,000 lbf (1,600 kN) Atlas D
Propellant	RP-1/LOX
First stage
Powered by	1
Maximum thrust	60,000 lbf (270 kN) Atlas D
Propellant	RP-1/LOX

Convair X-11 / SM-65 Atlas
Place of origin	United States
Service history
In service	1959–1964
Used by	United States Air Force
Wars	Cold War
Production history
Manufacturer	Convair
Specifications
Mass	255,950 lb (116,100 kg) for Atlas D w/o payload, 260,000 lb (117,900 kg) for Atlas D with Mk 2/3 RV and W49 warhead, 268,000 lb (121,560 kg) for Atlas E&F with Mk 4 RV and W38 warhead
Length	75 ft 1 in (22.89 m) with Mk 2 re-entry vehicle, 82 ft 6 in (25.15 m) with Mk 3
Width	16 ft 1 in (4.90 m)
Diameter	10 ft 0 in (3.05 m)
Engine	2 ×Rocketdyne XLR-89booster rocket engines each 150,000 lbf (670 kN) sharing one turbopump (Atlas A) 1 ×Rocketdyne LR-105sustainer rocket engine, 2 × Rocketdyne XLR-89 booster rocket engines each 150,000 lbf (670 kN) sharing one turbopump (Atlas B, C) 1 × Rocketdyne LR-105 sustainer rocket engine, 2 × LR89 booster engines with independent turbopumps each 165,000 lbf (730 kN) (Atlas D, E, F, G) + 2 ×Rocketdyne LR-101vernier engineswith 1,000 lbf (4.4 kN) of thrust fed by LR-105 sustainer engine turbopump(s) (Atlas A, B, C, D, E, F, G)
Accuracy	CEP4,600 ft (1,400 m)
References

SM-65 Atlas
Service history
In service	1959–1964
Production history
Designed	1953 (XB-65)
Produced	1959–1965
No.built	350 (all versions) Peak deployment level of 129 (30 D, 27 E, 72 F).
Variants	Atlas A, B/C, D, E/F (ICBMs) SLV-3/3A/3C (NASA use)

Development dates to 1946, but over the next few years the project underwent several cancellations and re-starts. The deepening of theCold Warand intelligence showing theSoviet Unionwas working on an ICBM design led to it becoming a crash project in late 1952, along with the creation of several other missile projects to ensure one would enter service as soon as possible. The first test launch was carried out in June 1957, which failed. The first success of the SovietR-7 Semyorkain August gave the program new urgency, leading to the first successful Atlas A launch in December. Of the eight flights of the A model, only three were successful, but the later models demonstrated increasing reliability and the D model was cleared for use.

Atlas C was declared operational in September 1959. Even at that time it was considered less than ideal as it had to be fuelled immediately before launch and thus had very slow reaction times. The Air Force still saw itsstrategic bombersas its primary force and considered Atlas as a last-ditch weapon that would ensure a counterattack in the case the Soviets attempted a sneak attack on the US bomber bases. The initial versions were stored at ground level and thus subject to attack by Soviet bombers, which greatly reduced their suitability for this role. Starting with the F models they were stored in underground silos that offered some protection from air attack. New designs, especially theMinuteman,rendered Atlas obsolete and it was retired from the ICBM role by 1965.

These disadvantages had no bearing on its use for space launches, and Atlas-derivedlaunch vehiclesserved a long history as launchers. Even before its ICBM use ended in 1965, Atlas had placed fourProject Mercuryastronauts in orbit and was becoming the foundation for a family of successful space launch vehicles, most notablyAtlas AgenaandAtlas Centaur.Mergers led to the acquisition of the Atlas Centaur line by theUnited Launch Alliance.Today ULA supports the largerAtlas V,which combines theCentaur upper stagewith a new booster. Until 1995, many retired Atlas ICBMs were refurbished and combined with upper stages to launch satellites.

History

Theodore von Kármán,left, is joined by Air Force and NASA officials while inspecting two of the models used in the high velocity, high altitude wind tunnels at Arnold Air Force Base. The missiles areAGARD-Band Atlas Series-B. (1959)

Atlas was the first US ICBM and one of the first large liquid-fueled rockets. As such, its early development was quite chaotic, with plans changing rapidly as flight tests revealed issues.

Atlas began in 1946 with the award of an Army Air Forces research contract toConvairfor the study of a 1,500-to-5,000-mile (2,400 to 8,000 km) range missile that might at some future date carry a nuclear warhead. ThisMX-774project was named for theAtlasofGreek mythologyand the contractor's parentAtlas Corporation.At the time, the smallest atomic warheads were all larger than the maximum theoretical payloads of the planned long range missiles, so the contract was canceled in 1947, but the Army Air Forces allowed Convair to launch the three almost-completed research vehicles using the remaining contract funds. The three flights were only partially successful, but did show that balloon tanks and gimbaled rocket engines were valid concepts.

A second development contract was awarded toConvairon 23 January 1951 for what was then called MX-1593, with a relatively low priority.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. This, in addition to theSoviet Union's 1953Joe 4dry fuelthermonuclear weapontest and the CIA learning that the Soviet ICBM program was making progress, led to the project being dramatically accelerated. Project Atlas was assigned the highest Air Force development priority on 14 May 1954 by GeneralThomas D. White.

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.

The missile was originally designated as the XB-65 experimental bomber; in 1955 it was redesignated SM-65 ( "Strategic Missile 65" ) and, from 1962, it became CGM-16. This letter "C" stood for "coffin" or "Container", the rocket being stored in a semi-hardened container; it was prepared for launch by being raised and fueled in the open. The Atlas-F (HGM-16) was stored vertically underground, but launched after being lifted to the surface.

By 1965, with the second-generationTitan IIhaving reached operational status, the Atlas was obsolete as a missile system and had been phased out of military use. Many of the retired Atlas D, E, and F missiles were used for space launches into the 1990s.

The penetrating lubricantWD-40found its first use as a corrosion-inhibiting coating for the outer skin of the Atlas missile.

Missile details

The Atlas's complicated, unconventional design proved difficult to debug compared with rocket families such as Thor and Titan which used conventional aircraft-style structures and two stage setups and there were dozens of failed launches during the early years. After watchingAtlas Serial 7Dexplode shortly after its nighttime launch,Mercury astronautGus Grissomremarked "Are we really going to get on top of one of those things?"The numerous failures led to Atlas being dubbed an "Inter County Ballistic Missile" by missile technicians, but by 1965 most of the problems had been worked out and it was a reliable launch vehicle. Nearly every component in the Atlas managed to fail at some point during test flights, from the engine combustion chambers to the tank pressurization system to the flight control system, but Convair engineers noted with some pride that there had never been a repeat of the same failure more than three times, and every component malfunction on an Atlas flight was figured out and resolved. Some of the repeat failures were also the result of rushed launch schedules and could have been avoided. The last major design hurdle to overcome was unstable engine thrust, which caused three Atlas missiles (Serial 51D and 48D in 1960 and Serial 27E in 1961) to explode on their launching stands.

Pressure stabilized tanks

Atlas was unusual in its use ofballoon tanksfor the propellants, made of very thinstainless steelwith minimal or no rigid support structures, as already pioneered by the SovietR-5first launched in 1953.Pressure in the tanks provides the structural rigidity required for flight. An Atlas rocket would collapse under its own weight if not kept pressurized, and had to have 5 psi (34 kPa) nitrogen in the tank even when not fueled.The rocket had two small thrust chambers on the sides of the tank calledvernier rockets.These provided fine adjustment of velocity and steering after the sustainer engine shut down.

'Stage-and-a-half'

Atlas was informally classified as a "stage-and-a-half" rocket, with a central sustainer engine and set of two booster engines that were all started at launch, each drawing from a single set of propellant tanks.Mostmultistage rocketsdrop both engines and fuel tanks simultaneously before firing the next stage's engines. However, when the Atlas missile was being developed, there was doubt as to whether a rocket engine could be air-started. Therefore, the decision was made to ignite all of the Atlas' engines at launch; the booster engines would be discarded, while the sustainer continued to burn.A stage of a liquid propellant rocket normally consists of both propellant tanks and engines, so jettisoning one or more engines only is equivalent to "half a stage". At staging, the booster engines would be shut off and a series of mechanical and hydraulic mechanisms would close the plumbing lines to them. The booster section would then be released by a series of hydraulic clamps (aside from the early test model Atlas B, which used explosive bolts) and slide off the missile on two tracks. From there on, the sustainer andvernierswould operate by themselves. Booster staging took place at roughly two minutes into launch, although the exact timing could vary considerably depending on the model of Atlas as well as the particular mission being flown. This "stage-and-a-half" design was made possible by the extremely light weightballoon tanks.The tanks made up such a small percentage of the total booster weight that the mass penalty of lifting them to orbit was less than the technical and mass penalty required to throw half of them away mid-flight. However, technology advanced quickly and not long after design work on Atlas was completed, Convair rival Martin proposed a solution to the air-starting problem. TheirTitan Imissile, developed as an Atlas backup, had a conventional two stage design.

Engines

The booster engine consisted of two large thrust chambers. The Atlas A/B/C/D had a single turbopump assembly and gas generator driving both booster engines; the A/B/C had an interim engine with lower thrust while the D-series had the full-up engines delivering 303,000 pounds of thrust.On the Atlas E/F, each booster engine had a separate pump and gas generator. Later space launcher variants of the Atlas used the MA-5 propulsion system with twin turbopumps on each booster engine, driven by a common gas generator.The boosters were more powerful than the sustainer engine and did most of the lifting for the first two minutes of flight. In addition to pitch and yaw control, they could also perform roll control in the event of a vernier failure. The sustainer engine on all Atlas variants consisted of a single thrust chamber with its own turbopump and gas generator, which also powered two small pressure-fed vernier engines.The verniers provided roll control and final velocity trim. The total sea level thrust of all five thrust chambers was 360,000lb_f(1,600kN) for a standard Atlas D. Atlas E/F had 375,000 pounds of thrust. Total sea level thrust for these three-engine Atlas Es and Fs was 389,000 lb_f(1,730 kN).Launchervariants of the Atlas often had performance enhancements to the engines.

Guidance

The Atlas missiles A through D used radioguidance:the missile sent information from itsinertial systemto a ground station by radio, and received course correction information in return. The Atlas E and F had completely autonomousinertial guidancesystems.

The ground based guidance computer was a key part of the missile system, until guidance computers wereminiaturizedenough to be installed inside the missile.Isaac L. Auerbachdesigned the Burroughs guidance computer for the Atlas ICBM missiles. The Burroughs guidance computer was one of the firsttransistor computers.It processed24-bitdata using18-bitinstructions. A total of 17 of these ground computers were delivered. These same ground computers was later used forAtlas-Able,Project Mercury,and other early spacecraft.

Warhead

The warhead of the Atlas D was originally the G.E. Mk 2 "heat sink"re-entry vehicle(RV)with aW49thermonuclear weapon,combined weight 3,700 lb (1,680 kg) and yield of 1.44megatons(Mt). The W49 was later placed in a Mk 3 ablative RV, combined weight 2,420 lb (1,100 kg). The Atlas E and F had an AVCO Mk 4 RV containing aW38thermonuclear warheadwith a yield of 3.75 Mtwhich wasfuzedfor either air burst or contact burst. The Mk 4 RV also deployedpenetration aidsin the form ofmylarballoons which replicated the radar signature of the Mk 4 RV. The Mk 4 plus W-38 had a combined weight of 4,050 lb (1,840 kg). The Atlas missile's warhead was over 100 times more powerful than thebomb dropped over Nagasakiin 1945.

Comparison with R-7

TheR-7 Semyorkawas the first Soviet ICBM and similarly started all engines before launch to avoid igniting a large liquid fuel engine at high altitudes. However, the R-7 had a central sustainer section, with four boosters attached to its sides. The large side boosters required use of an expensive launch pad and prevented launching the rocket from a silo. Like the Atlas, the use ofcryogenicliquid oxygenmeant that the missile could not be kept in the state of flight readiness indefinitely and was largely useless for its intended purpose (military) and was similarly developed into a space launch vehicle, initially deliveringSputnikandVostokinto orbit. TheSoyuz rocketis descended from the R-7 and remains in use today.

Missile versions

SM-65A Atlas

Main article:SM-65A Atlas

Atlas, test number 449, Air Force Missile Test Center.

TheConvairX-11/SM-65A Atlas/Atlas Awas the first full-scale prototype of the Atlas missile, first flying on 11 June 1957.It was a test model designed to verify the structure and propulsion system, and had no sustainer engine or separable stages. The first three Atlas A launches used an early Rocketdyne engine design with conical thrust chambers and only 135,000 pounds of thrust. By the fourth Atlas test, they were replaced by an improved engine design that had bell-shaped thrust chambers and 150,000 pounds of thrust.

There were eight Atlas A test flights, conducted in 1957–58, of which four were successful. All were launched fromCape Canaveral Air Force Station,at eitherLaunch Complex 12orLaunch Complex 14.

SM-65B Atlas

Launch of an Atlas B ICBM.

Main article:SM-65B Atlas

TheConvair X-12/SM-65Bwas the second prototype version, introducing thestage and a halfsystem that was a hallmark of the Atlas rocket program. This version was the first American rocket to achieve a flight distance that could be considered intercontinental when it flew 6,325 miles (10,180 km).

The Atlas B was first flown on 19 July 1958. Of ten total flights, nine weresub-orbitaltest flights of the Atlas as anIntercontinental Ballistic Missile,with five successful missions and four failures; the other flight placed theSCORE satelliteinto orbit. All launches were conducted fromCape Canaveral Air Force Station,at Launch Complexes11,13and14.

SM-65C Atlas

Main article:SM-65C Atlas

Atlas C missile sitting on its launch pad.

TheSM-65C Atlas,orAtlas Cwas the third prototype Atlas version, a more refined model with improved, lighter-weight components. a bigger LOX tank, and a smaller fuel tank. First flown on 24 December 1958, it was the final development version. It was originally planned to be used as the first stage of theAtlas-Ablerocket, but following an explosion during a static test on 24 September 1959, this was abandoned in favor of the Atlas D.Six flights were made, all sub-orbital ballistic test flights of the Atlas, with three tests succeeding, and three failing.All launches were conducted from Cape Canaveral Air Force Station, at Launch Complex 12.

SM-65D Atlas

Main article:SM-65D Atlas

SM-65D Atlas missile 58-220, F. E. Warren AFB.

TheSM-65D Atlas,orAtlas D,was the first operational version of the Atlas missile and the basis for all Atlas space launchers, debuting in 1959.Atlas D weighed 255,950 lb (116,100 kg) (without payload) and had an empty weight of only 11,894 lb (5,395 kg); the other 95.35% was propellant. Dropping the 6,720 lb (3,048 kg) booster engine and fairing reduced the dry weight to 5,174 lb (2,347 kg), a mere 2.02% of the initial gross weight of the vehicle (still excluding payload). This very low dry weight gave Atlas D a range of up to 9,000 miles (14,500 km), or to orbit payloads without requiring an upper stage.It first flew on 14 April 1959.

To provide the United States with an interim or emergency ICBM capability, in September 1959 the Air Force deployed three SM-65D Atlas missiles on open launch pads atVandenberg AFB,California, under the operational control of the576th Strategic Missile Squadron,704th Strategic Missile Wing.Completely exposed to the elements, the three missiles were serviced by a gantry crane. One missile was on operational alert at all times.They remained on alert until 1 May 1964.

SM-65E Atlas

Main article:SM-65E Atlas

Atlas-E missile (s/n 5E), Cape Canaveral LC-11.

TheSM-65E Atlas,orAtlas-E,was the first 3-engine operational variant of the Atlas missile, the third engine resulting from splitting the two booster thrust chambers into separate engines with independent sets of turbopumps. It first flew on 11 October 1960, and was deployed as an operationalICBMfrom September 1961 until March 1965.

A major enhancement in the Atlas E was the new all-inertial system that obviated the need for ground control facilities. Since the missiles were no longer tied to a central guidance control facility, the launchers could be dispersed more widely in what was called a 1 × 9 configuration, with one missile silo located at one launch site each for the nine missiles assigned to the squadron.

Atlas-E launches were conducted from Cape Canaveral Air Force Station, at Launch Complexes 11 and 13, and Vandenberg Air Force Base atVandenberg AFB Operational Silo Test Facility,Vandenberg AFB Launch Complex 576 andVandenberg AFB Space Launch Complex 3.

SM-65F Atlas

Main article:SM-65F Atlas

Convair SM-65F Atlas 532 550 SMS Site 02 Abilene KS.

TheSM-65F Atlas,orAtlas-F,was the final operational variant of the Atlas missile. It first flew on 8 August 1961, and was deployed as an operational ICBM between September 1962 and April 1965.

The Atlas F was essentially a quick-firing version of the Atlas E, modified to be stored in a vertical position inside underground concrete and steel silos. It was nearly identical to the E version except for interfaces associated with their different basing modes (underground silo for F) and the fuel management system.When stored, the missile sat atop an elevator. If placed on alert, it was fueled withRP-1(kerosene) liquid fuel, which could be stored inside the missile for extended periods. If a decision was made to launch, it was fueled withliquid oxygen.Once the liquid oxygen fueling was complete, the elevator raised the missile to the surface for launching.

This method of storage allowed the Atlas F to be launched in about ten minutes,a saving of about five minutes over the Atlas D and Atlas E, both of which were stored horizontally and had to be raised to a vertical position before being fueled.

Atlas-F launches were conducted from Cape Canaveral Air Force Station, at Launch Complexes 11 and 13, and Vandenberg Air Force Base atOSTF-2,Vandenberg AFB Launch Complex 576 and Vandenberg AFB Space Launch Complex 3.

Operational deployment

SM-65 Atlas deployment sites: SM-65D (Red), SM-65E (Purple), SM-65F (Black)

Strategic Air Commanddeployed 13 operational Atlas ICBM squadrons between 1959 and 1962. Each of the three missile variants, the Atlas D, E, and F series, were deployed and based in progressively more secure launchers.

Service history

The number of Atlas intercontinental ballistic missiles in service, at the end of each year:

Date	CGM-16D (Atlas D)	CGM-16E (Atlas E)	HGM-16F (Atlas F)
1959	6	0	0
1960	12	0	0
1961	30	27	0
1962	30	27	72
1963	20	27	72
1964	0	0	72

Atlas-D deployment

Atlas-D ICBM launching from semi-hardened "coffin" bunker at Vandenberg AFB, California.

In September 1959 the first operational Atlas ICBM squadron went on operational alert atF.E. Warren AFB,Wyoming equipped with sixSM-65D Atlasmissiles based in above-ground launchers. Three additional Atlas D squadrons, two near F.E. Warren AFB, Wyoming, and one atOffutt AFB,Nebraska,were based in above-ground launchers that provided blast protection against over-pressures of only 5 pounds per square inch (34 kPa). These units were:

• 389th Strategic Missile Wing

Francis E. Warren AFB,Wyoming(2 September 1960 – 1 July 1964)

564th Strategic Missile Squadron(6 missiles)

565th Strategic Missile Squadron(9 missiles)

• 385th Bombardment (later Strategic Aerospace) Wing

Offutt AFB,Nebraska(30 March 1961 – 1 October 1964)

549th Strategic Missile Squadron(9 missiles)

The first site at Warren for the 564th SMS consisted of six launchers grouped together, controlled by two launch operations buildings, and clustered around a central guidance control facility. This was called the 3 × 2 configuration: two launch complexes of three missiles each constituted a squadron.

At the second Warren site for the 565th SMS and at Offutt AFB, Nebraska, for the 549th SMS, the missiles were based in a 3 x 3 configuration: three launchers and one combined guidance control/launch facility constituted a launch complex, and three complexes comprised a squadron. At these later sites the combined guidance and control facility measured 107 by 121 ft (33 by 37 m) with a partial basement. A dispersal technique of spreading the launch complexes were 20 to 30 miles (30 to 50 km) apart was also employed to reduce the risk that one powerful nuclear warhead could destroy multiple launch sites.

Atlas-E deployment

The SM-65E Atlas were based in horizontal "semi-hard" or "coffin" facilities that protected the missile against over-pressures up to 25 psi (170 kPa). In this arrangement the missile, its support facilities, and the launch operations building were housed in reinforced concrete structures that were buried underground; only the roofs protruded above ground level. These units were:

• 92nd Bombardment (later Strategic Aerospace) Wing

Fairchild Air Force Base,Washington(28 September 1961 – 17 February 1965)

567th Strategic Missile Squadron,(9 missiles)

• 21st Strategic Aerospace Division

Forbes AFB,Kansas(10 October 1961 – 4 January 1965)

548th Strategic Missile Squadron,(9 missiles)

• 389th Strategic Missile Wing

Francis E. Warren AFB,Wyoming(20 November 1961 – 4 January 1965)

566th Strategic Missile Squadron(9 missiles)

Atlas-F deployment

The sixSM-65F Atlassquadrons were the first ICBMs to be stored vertically in underground silos. Built of heavily reinforced concrete, the huge silos were designed to protect the missiles from over-pressures of up to 100 psi (690 kPa).These units were:

• 310th Bombardment (later Strategic Aerospace) Wing

Schilling AFB,Kansas(9 September 1962 – 1 February 1965)

550th Strategic Missile Squadron(12 missiles)

• 98th Strategic Aerospace Wing

Lincoln AFB,Nebraska(15 September 1962 – 10 March 1965)

551st Strategic Missile Squadron(12 missiles)

• 11th Bombardment (later Strategic Aerospace) Wing

Altus AFB,Oklahoma(9 October 1962 – 30 December 1964)

577th Strategic Missile Squadron(12 missiles)

• 96th Bombardment (later Strategic Aerospace) Wing

Dyess AFB,Texas(15 November 1962 – 1 December 1964)

578th Strategic Missile Squadron(12 missiles)

• 6th Bombardment (later Strategic Aerospace) Wing

Walker AFB,New Mexico(30 November 1962 – 5 January 1965)

579th Strategic Missile Squadron(12 missiles)

• 820th Air (later Strategic Aerospace) Division

Plattsburgh AFB,New York(20 December 1962 – 12 March 1965)

556th Strategic Missile Squadron(12 missiles)

The Atlas F's employment was dangerous due to the flammability of the stored liquid rocket fuels. Four sites and their missiles were destroyed during propellant loading exercises (known as PLXs) when liquid oxygen leaked and fires ensued. On 1 June 1963 Roswell's site 579-1 was destroyed by explosion and fire. On 13 February 1964 Roswell's site 579-5 was destroyed, and a month later on 9 March 1964 site 579-2 was also destroyed by explosion and fire. Finally, on 14 May 1964 an Altus AFB site, 577-6 in Frederick, Oklahoma, was also destroyed by explosion and fire during a PLX. Fortunately the crews all survived. None of the damaged sites were repaired or returned to service.

Retirement as an ICBM

After thesolid-fuelLGM-30 Minutemanhad become operational in early 1963, the Atlas became rapidly obsolete.By October 1964, all Atlas D missiles had been phased out, followed by the Atlas E/F in April 1965. About 350 Atlas ICBMs of all versions were built, with a peak deployment level of 129 (30 D, 27 E, 72 F). Despite its relatively short life span, Atlas served as the proving ground for many new missile technologies. Perhaps more importantly, its development spawned the organization, policies, and procedures that paved the way for all of the later ICBM programs.

After its retirement from operational ICBM service in 1965, the ICBMs were refurbished and used for close to forty years as space launch vehicle boosters.

Atlas-A to -C launch history

SM-65A (Atlas A) variant launch history

1965 graph of Atlas launches, cumulative by month with failures highlighted (pink) along with USAF Titan II and NASA use of ICBM boosters for Projects Mercury and Gemini (blue). Apollo–Saturn history and projections shown as well.

Eight flights of Atlas A occurred during the history of this variant.

(SM-65A) Date	Time (GMT)	Pad	Serial	Apogee	Outcome
1957-06-11	19:37	LC-14	4A	2 km (1.2 mi)	Failure
1957-09-25	19:57	LC-14	6A	3 km (1.9 mi)	Failure
1957-12-17	17:39	LC-14	12A	120 km (75 mi)	Success
1958-01-10	15:48	LC-12	10A	120 km (75 mi)	Success
1958-02-07	19:37	LC-14	13A	120 km (75 mi)	Failure
1958-02-20	17:46	LC-12	11A	90 km (56 mi)	Failure
1958-04-05	17:01	LC-14	15A	100 km (62 mi)	Success
1958-06-03	21:28	LC-12	16A	120 km (75 mi)	Success

SM-65B (Atlas B) variant launch history

Ten flights of Atlas B occurred during the history of this variant.

(SM-65B) Date	Time (GMT)	Pad	Serial	Apogee	Outcome	Remarks
1958-07-19	17:36	LC-11	3B	10 km (6.2 mi)	Failure
1958-08-02	22:16	LC-13	4B	900 km (560 mi)	Success
1958-08-29	04:30	LC-11	5B	900 km (560 mi)	Success
1958-09-14	05:24	LC-14	8B	900 km (560 mi)	Success
1958-09-18	21:27	LC-13	6B	100 km (62 mi)	Failure
1958-11-18	04:00	LC-11	9B	800 km (500 mi)	Failure
1958-11-29	02:27	LC-14	12B	900 km (560 mi)	Success	First full-range test flight
1958-12-18	22:02	LC-11	10B	N/A	Success	PlacedSCOREsatellite into 185 km (115 mi) x 1,484 km (922 mi) x 32.3° orbit
1959-01-16	04:00	LC-14	13B	100 km (62 mi)	Failure
1959-02-04	08:01	LC-11	11B	900 km (560 mi)	Success

SM-65C (Atlas C) variant launch history

Six flights of Atlas C occurred during the history of this variant.

(SM-65C) Date	Time (GMT)	Pad	Serial	Apogee	Outcome
1958-12-24	04:45	LC-12	3C	900 km (560 mi)	Success
1959-01-27	23:34	LC-12	4C	900 km (560 mi)	Failure
1959-02-20	05:38	LC-12	5C	100 km (62 mi)	Failure
1959-03-19	00:59	LC-12	7C	200 km (120 mi)	Failure
1959-07-21	05:22	LC-12	8C	900 km (560 mi)	Success
1959-08-24	15:53	LC-12	11C	900 km (560 mi)	Success

Survivors

• HGM-16F Atlas is on display at theNational Museum of the United States Air ForceinDayton, Ohio.For years the missile was displayed outside the museum. In 1998 it was removed from display. It was restored by the museum's restoration staff and returned to display in the museum's new Missile Silo Gallery in 2007. The stage is currently in storage at the museum.The white nose cone atop the museum's Atlas is an AVCO IV re-entry vehicle built to contain a nuclear warhead. This nose cone actually stood alert in defense of the United States, as it was initially installed on an Atlas on 2 October 1962 at a Denton Valley launch site nearClyde, Texas.
• Atlas 8A is displayed in front of theStrategic Air Command & Aerospace Museumin Ashland, Nebraska; reconfigured as an Atlas D.
• Atlas 2E is on display in front of theSan Diego Air & Space MuseumatGillespie Field,El Cajon, California.
• Atlas 2D mounted with a Mercury capsule is on display in the Rocket Garden at theKennedy Space Center Visitor Complex,Merritt Island, Florida.
• Atlas 10F is on display at theU.S. Space & Rocket Centerin Huntsville, Alabama.

Former survivor:

• Atlas 5A (56–6742) was formerly on display on the lawn in front of theCanada Science and Technology MuseuminOttawa, Ontario, Canada,but was removed in February 2015 and dismantled.

• 
  Atlas 8A,Strategic Air Command & Aerospace Museum(reconfigured as Atlas D)
• 
  Atlas 2E,San Diego Air & Space Museum,Gillespie Field
• 
  Atlas 2D,Kennedy Space Center Visitor Complex(mounted with a Mercury capsule)
• 
  Atlas 10F,U.S. Space & Rocket Center(left, on transporter)
• 
  Atlas 5A (56–6742),Canada Science and Technology Museum

Gallery

Convair XSM-65A being launched

Convair XSM-65B being launched

Atlas C missile sitting on its launch pad, 1957/58

Launch of an SM-65E Atlas

Launch of an SM-65F Atlas

See also

• Strategic Air Command

Aircraft of comparable role, configuration, and era

• Soviet R-7 (later Soyuz) family
• SM-68 Titan I
• SM-68 Titan II

Related lists

• List of military aircraft of the United States
• List of missiles

References

This article incorporatespublic domain materialfrom theAir Force Historical Research Agency

Further reading

• Gunston, Bill (1979).Illustrated Encyclopedia of the World's Rockets & Missiles.London: Salamander Books.ISBN0-517-26870-1.
• Walker, Chuck, & Powell, Joel (2005).Atlas The Ultimate Weapon.Burlington, Ontario, Canada: Apogee Books.ISBN1-894959-18-3.
• Maurer, Maurer, ed. (1982) [1969].Combat Squadrons of the Air Force, World War II(PDF)(reprint ed.). Washington, DC: Office of Air Force History.ISBN0-405-12194-6.LCCN70605402.OCLC72556.Archived(PDF)from the original on 20 December 2016.

External links

• A film clip"Atlas in Orbit. Radios Ike's Message of Peace To World, 1958/12/22 (1958)"is available for viewing at theInternet Archive
• Karel Jan Bossart, Ir.
• Atlas launch vehicle profile
• Atlas Dfrom Encyclopedia Astronautica
• Atlas ICBM Information/History
• Video of an early Atlas launch in 1960
• 1958 Video of "Atlas in Orbit" Newsreel
• Atlas ICBM Launch on 5/23/1960Video
• 556th Missile Sites
• Atlas D Booster Package Jettison (BPJ) Test Footage