Sunday, March 15, 2009

Atlas Missile

ATLAS ICBM

Although not the war-winning weapon that some in the German high command had hoped for, the A-4/V-2 "vengeance weapon” nonetheless introduced the world at large to the ballistic missile, and the design teams and much of the actual hardware from the program helped form the basis of postwar missile development in both the U.S. and Soviet Union.

As a strategic weapon, the A-4 had several shortcomings. A one-ton warhead and a CEP measured in many thousands of feet made it very unlikely to destroy a point target, while a maximum range of less than 200 miles, while adequate for the use it saw in Europe, was far too short for a weapon that would have to strike at Soviet targets from American soil. Nonetheless, the A-4 definitely pointed the way towards the ICBM, and both the US and USSR intently searched for A-4 personnel, components, and assembled missiles in early postwar Germany. The Germans themselves had made numerous paper studies of improved V-2s and long-range weapons using derived technology, and these were snapped up as well. The American Operation Paperclip managed to bring back Werner von Braun and much of his team, and enough V-2s and associated materials to conduct test launches into the early 1950s.

Convair was working towards a heavy ballistic missile under the MX-774 project by the late 1940s, but despite the V-2's measure of success, there was no consensus that such vehicles could be evolved into intercontinental range weapons. Cruise missiles, based in the most part on conventional aircraft technology, were much lower risk, and there was also interest in so-called boost-glide vehicles that would ascend in missile fashion and then fly a more conventional trajectory towards a target. Some German research in this area had gone on during the war, and the planned A-10 ICBM would have had a winged upper stage derived from the A-4/V-2. MX-774A was an alternative design using such a configuration, but this was not pursued, as the pure ballistic approach was chosen instead.

MX-774B was to be a short-range test article generally in the A-4/V-2 class, but with significant new features such as engine nozzles that were gimbaled to provide control. And while the A-4's entire structure, airframe and warhead both, stayed together over the weapon's entire trajectory, MX-774B's nose cone was to detach after termination of the booster firing. As planned, MX-774B would not enter operational use itself, merely proving the technology for a proposed service weapon, the MX-774C Manhattan. This would have been sized to carry a large first generation fission weapon over an intercontinental range. Funding for the project was cut as part of postwar cutbacks, but three MX-774Bs were able to be launched, and although these were not wholly successful, Convair would continue to work on ICBM technology in anticipation of another program being started up eventually. The -774 did show that the weight of a missile could be drastically cut by using a lightweight, unreinforced outer skin. Although this meant that constant pressurization would be needed to keep the airframe from crumbling, it also allowed reinforcing structures to be left out, thus increasing payload and range.

The Atlas program really got its start in 1950, as the Cold War turned hot and the USAF began looking once again at the ICBM idea. Convair began work on the MX-1953 project, with early studies calling for massive missiles powered by up to seven engines. Such size was seen at the time as being necessary, since accuracy would be much poorer than bomber-dropped weapons, necessitating a physically large high-yield fission weapon to compensate. The development of deliverable megaton-yield fusion devices pointed the way towards smaller, yet more powerful nuclear weapons, and by the time that the Atlas design had been set in 1955, it was for a significantly smaller missile.

At the time of Atlas' creation, experience with missiles of this class was non-existent, and relying on a multi-stage weapon was perhaps too risky, as much work would have to be done to make the upper stages reliably ignite at altitude. Atlas was thus a “stage and a half” missile, with two boosters in fairings on the side of the core vehicle, which would have a sustainer engine. All three engines were started during liftoff, with the boosters later being jettisoned

As the US grew ever more worried about Soviet strategic advances, the Atlas program received the highest priority rating by President Eisenhower in late 1955, expediting necessary materials and manpower.

TEST MISSILES

The Atlas-As were far from being production missiles, as they were only intended to demonstrate the airframe and booster engines; lacking the core engine (which was not yet available), they were substantially lighter than production models and were intended for only short-range flights. The first attempt to launch an Atlas was on June 11, 1957 from Patrick AFB, Florida, but the missile failed at a low altitude. The Air Force had tried to keep the launch, and even the type of missile a secret, but this was hardly practical, given an open society and a launch base close to population centers. Despite the attempted cloak of secrecy, the public and media could not help but to be aware of the impending test, and the failure occurred so close to land that numerous photos were taken and published of the Atlas falling into the sea. It would be December 1957 before a successful Atlas flight would be made.

Testing of the Atlas-B began with an attempt at a three-engined flight on July 19, 1958, this ending when the vehicle exploded. On August 2 of that year a B-model successfully flew with a live sustainer. This was still not a long-range attempt, but twenty-six days later a missile fitted with radio-inertial guidance achieved a 3,000-mile flight. On the night of November 28, 1958, the Soviet lead in long-range rocketry was narrowed when the Atlas-12B flew over 6,300 miles. An entire Atlas-B was fired into orbit in December 1958 as part of Project Score, being fitted with a radio transmitter that broadcast a taped greeting from President Eisenhower, thereby pointing the way towards the era of the communications satellite. The Atlas-Cs were lightweight vehicles closer to production standard that also tested nose cones, including both heatsink and ablative designs.

ATLAS-D

Atlas-D was the first operational member of the family, being fitted with more powerful booster engines and a warload in the form of a W49 device rated at 1.44 megatons, and carried in a Mk.3 RV of ablative design. The first Atlas-D was fired in April 1959, and following a successful SAC launch on September 9 of that year, a squadron at Vandenberg with several missiles became operational.SAC had now entered the ICBM age, but the command's foothold was tenuous, as the Vandenberg missiles were but a stopgap; fired from gantries, these Ds were immensely vulnerable to conventional attack or even adverse weather, to say nothing of a nearby nuclear strike. As the USSR moved more megatonnage to increasingly accurate missiles, the need to make ICBMs more survivable led to ever “harder” basing options. Crews also had to gain experience in operating an maintaining the new weapons system, and labor difficulties snarled the construction of bases.

The gantry-launched Ds were followed by slightly more survivable examples housed in above-ground concrete “coffins”; when alerted, they would be raised to the vertical and then fueled. The “soft” coffins still provided virtually no protection from attack, but at least kept the missiles out of heavy weather. F.E. Warren AFB received two Atlas-D squadrons, while one squadron was based at Offutt AFB,

Actually using the Atlas-Ds in anger would have been a protracted affair even without the erection and fueling process, as radio-inertial guidance was used, this allowing only a single missile to be launched at a time. Atlas-Ds saw considerable use in the space launch role, and NASA used the missile as the basis for the Mercury-Atlas vehicle that first put Americans into orbit. A pair of Atlas-Ds were used as launchers for Project FIRE, which was run in 1964 to study reentry heating data on subscale models representing the shape of the Apollo Command Module. The Atlases were used to boost Antares 2 upper stages up to orbital altitudes, where their solid motors would fire, ramming the 200lb CM test articles into the atmosphere at hypersonic speed, replicating conditions that full-scale spacecraft would have to endure at the end of a mission.

Wings Models (formerly Eagle Talon) makes a 1/48 scale Atlas-D model with the option to build the kit as a Mercury Atlas.

ATLAS-E

The second operational Atlas, the SM-65E was first flown on October 11, 1960. The E-model was be the first service variant to use purely inertial guidance, although some Atlas-Ds had flown with the system for testing purposes. The payload was also different from the previous model, consisting of a more powerful 4 megaton-yield W38 warhead in a Mk.4 reentry vehicle. On July 7, 1961, an Atlas-E launched from Cape Canaveral made a record 9,050-mile flight that ended in the Indian Ocean. Although coffin basing was again used, the Atlas-E installations were somewhat harder, being rated at around 25 PSI. Fairchild AFB, Washington, Forbes AFB in Kansas, and F.E. Warren AFB in Wyoming each had a single Atlas-E squadron by the fall of 1961, with each unit having nine missiles.

ATLAS-F

The last ICBM of the Atlas family, the HGM-65F Atlas-F was first launched on August 8, 1961. The Fs would be the most survivable Atlases, as coffin basing had given way to an arrangement wherein the missile would sit in a hardened underground silo; when alerted the weapon would be fueled with oxidizer and moved aboveground for firing. Each silo was connected by a tunnel to a spherical launch control center and support installation, which was also underground.

Unlike previous Atlases, F-model testing would take place exclusively from the west coast. On August 10, 1962, an Atlas-F fired from Vandenberg had to destroyed shortly after lift-off, sending wreckage falling into the town of Betteravia, fortunately without causing any injuries.

Between September and December 1962, six units became operational with the last of the Atlases; the 550th SMS in Kansas, 551st in Nebraska, 577th at Altus AFB, Oklahoma, the 578th, the 579th at Walker AFB, New Mexico, and the 556th at Plattsburgh AFB, New York. Each squadron controlled a dozen missiles.

An Atlas-F converted to a space launch vehicle is launched from Vandenberg

Scale Models:

Anigrand Craftworks makes a 1/72 scale resin kit that can be finished as an Atlas-A/B/D.



Bibliography


magazine articles
“Atlas Burns After Launching” Aviation Week June 17, 1957 p.27 3 illustrations

“Atlas Traces Its Fall in Trail of Black Smoke” Aviation Week June 24, 1957 p.32-33 4 illustrations

“Shrouded Atlas ICBM Is Transported to Florida Test Center” Aviation Week November 11, 1957 p.34 1 illustration

“USAF Reports Successful Atlas Launching” Aviation Week December 23, 1957 p.22-23 5 illustrations

Photo: “Convair Atlas ICBM” Aviation Week December 30, 1957 cover

“Photo Shows Details of Atlas” Aviation Week January 13, 1958 p.27 1 illustration

Photo: “Atlas ICBM on Firing Pad” Aviation Week February 24, 1958 cover

“Support Complex Surrounds Atlas Missile Launch Site” Aviation Week March 17, 1958 p.22-23 6 illustrations

“Atlas Tracking Radar” Aviation Week April 28, 1958 [cover photo]

“Convair Atlas Complex at Cape Canaveral” Aviation Week June 16, 1958 p.163 1 illustration

[Photo: Atlas] Aviation Week June 16, 1958 p.189

[Photo: Atlas] U.S. News & World Report September 14, 1959 p.58

“U.S. Out Front In Missile Race?” U.S. News & World Report September 21, 1959 p.97

Photo: Atlas U.S. News & World Report September 28, 1959 p.63

Photo: Atlas U.S. News & World Report December 14, 1959 p.45

Photo: GE Mk.3 Nose Cone on Atlas. Aviation Week March 7, 1960 p.131

Photo: Convair Atlas ICBM Aviation Week March 7, 1960 p.127

“Ranges Exceeding 10,000 Miles Predicted for Atlas-E ICBM” Aviation Week March 21, 1960 p.34

Photo: “Avco Mk. IV Nose Cone” Aviation Week April 11, 1960 cover

“Avco RVX-4 Re-Entry Vehicle First Launched on Atlas 44-D” Aviation Week April 11, 1960 p.91 3 illustrations

“Atlas-51D Explodes at Cape Canaveral” Aviation Week April 25, 1960 p.82 1 illustration

“Atlas Uses Modified Nose Cone on Indian Ocean Shot” Aviation Week May 30, 1960 p.37 2 illustrations

[Photo: Atlas] Aviation Week June 20, 1960 p.139

“First Photos Show Atlas Being Fired From Coffin” Aviation Week June 27, 1960 p.35 1 illustration

Photo: “SAC Crewmen Mate GE Nose Cone to Atlas” Aviation Week July 4, 1960 cover

“Lift Trailer Used in Mating GE Re-Rentry Vehicle to Convair Atlas” Aviation Week July 4, 1960 p.48-51 13 illustrations

“Disputes May Delay 10 Atlas Complexes” Aviation Week July 18, 1960 p.31

“Atlas Launched on 7,000-mi. Flight” Aviation Week September 5, 1960 p.71 2 illustrations

Photo: “Convair Atlas At 250-mi. Altitude” Aviation Week November 14, 1960 cover

“Third Atlas Radio Guidance Site Now Operational” Aviation Week November 21, 1960 p.27 1 illustration

Photo: Atlas-E Aviation Week March 13, 1961 p.77

Photo: Atlas advertisement Aviation Week April 17, 1961 p.135

“Mk.5 Nose Cone on Atlas” Aviation Week May 15, 1961 p.28 1 illustration

“Boilerplate Atlas F” Aviation Week July 17, 1961 p.65 1 illustration

[Photo: Atlas] advertisement Aviation Week & Space Technology September 18, 1961 p.76

“Atlas ICBM Geared to Total Deployment” Aviation Week & Space Technology September 25, 1961 p.143-147 3 illustrations

“Project Fire to Study High-Speed Re-Entry” Aviation Week & Space Technology May 21, 1962 1 illustration

“Atlas-F Launched From Prototype Silo” Aviation Week & Space Technology August 6, 1962 p.35

[Photo: Atlas] advertisement Aviation Week & Space Technology July 15, 1963 p.6

[Photo: Atlas production line] advertisement Aviation Week & Space Technology July 22, 1963 p.99

[Photo: Atlas] Aviation Week & Space Technology September 16, 1963 p.99

[Photo: “Trident 1 reentry vehicle launched from Vandenberg”] Aviation Week & Space Technology June 24, 1974 cover


newspaper articles
Atlas Is Launched Successfully; ICBM Climbs on All 3 engines” The New York Times August 3, 1958 p.1 c.6

Milton Bracker “Fire on All Engines” The New York Times August 3, 1958 p.42 c.1

“Talking Satellite Heralds Era of Space Messages” The New York Times December 23, 1958 p.1

Jack Raymond “Combat Atlas Expected by Sept. 1” The New York Times July 29, 1959 p.1 1 illustration

“Atlas Hits Mark in 3,000-Mile Test” The New York Times August 29, 1958 p.4 c.5

Gladwin Hill “Atlas Declared Operational Now” The New York Times September 2, 1959

“Atlas Is Destroyed; Debris Hits Town” The New York Times August 11, 1962

“Atlas Blows Up in Its Site At New Mexico Desert Base” The New York Times March 10, 1964 p.75 c.4

Books

Photo: Atlas-D night launch. The History of the US Air Force David A. Anderton, p.165
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