113-460: 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
226-500: A W38 thermonuclear warhead with a yield of 3.75 Mt which was fuzed for either air burst or contact burst. The Mk 4 RV also deployed penetration aids in the form of mylar balloons 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 the bomb dropped over Nagasaki in 1945. The R-7 Semyorka
339-425: 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
452-429: A 320° loop, showering the area around the pad with flaming debris. Although only a few items were telemetered, the telemetry system failed during the prelaunch countdown anyway and film did not reveal any obvious cause of the control loss, but recovered debris discovered that the pitch gyro was either not running or the rotation speed was too low, and that 102D was still using the old Type B gyro canisters which did not have
565-439: A backup signal generated by the programmer. The missile landed within 9 miles (14 km) of the target area. On March 5, 1960, Missile 19D was undergoing a propellant loading exercise at 576-A2 at VAFB when a fuel leak started a fire on the pad that led to the explosion of the missile. The launch facility was written off due to the damage and not used again for almost 5 years. On March 8, 1960, Missile 44D launched from LC-11 on
678-495: A couple of cartwheels before the Range Safety destruct command was sent at T+26 seconds. This failure was attributed to wiring in the pitch gyro contacting the casing and shorting out the gyro motor. The guidance system rate beacon also failed at liftoff, thus it would have been impossible to transmit any discrete guidance commands to the missile had the flight continued. Atlas 74D (July 22) broke up 70 seconds into launch due to
791-458: A destructive pad fallback. The exact reason for the rough combustion was unclear, although it had occurred over a dozen times in static firing tests of the MA-2 engines. However, it was noted that the separate exhaust duct for the gas generator vent pipe had been removed from both LC-11 and LC-13 after engineers decided that it was unnecessary and impeded removal and installation of protective covers on
904-402: A failure of the pitch gyro either due to an improper motor speed setting or torquing signals. Missile 47D (September 12) lost sustainer thrust starting at T+220 seconds due to an apparent loss of helium control pressure to the gas generator. The sustainer completely shut down at T+268 seconds and the missile fell 480 miles (772 km) short of the target area. Making postflight analysis difficult
1017-560: A fuel leak and fire were suspected but launch film revealed an improperly attached insulation boot which came off at liftoff. Three Atlas Ds then successfully tested Nike-Zeus target missiles. In March, a series of operational SAC tests were carried out with minimal telemetry to reduce weight and allow the missiles to fly for as long a range as possible—five Atlas D and F flights. The first was 102D launched March 10 from 576-B3. The missile began to tumble out of control shortly after liftoff and self-destructed at T+33 seconds after having performed
1130-471: A fuel leak started. Tank pressure decreased until the intermediate bulkhead reversed at T+157 seconds and the missile exploded. This incident was similar in nature to an Atlas C failure earlier in the year and it resulted in a major investigation and redesign effort. The failure point was either the fuel staging disconnect valve or associated plumbing, and modifications were made to the disconnect valve, plumbing, booster separation system, jettison tracks, and even
1243-415: A hydraulic failure in the last few seconds of vernier solo phase and the warhead did not land on target. The missile did not carry temperature probes, but thrust section overheating was suspected. On October 7, Missile 163D exploded at T+75 seconds when the intermediate bulkhead reversed. Postflight investigation found that launch crews had loaded the helium bottles with insufficiently chilled gas, resulting in
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#17327728239051356-410: A lack of helium flow to the propellant tanks, which lost pressure during ascent. The last operational Atlas D missile test was Missile 158D on November 13. The flight was normal until T+112 seconds when sustainer hydraulic pressure began dropping, followed by missile explosion five seconds later. Because this was the program finale, Convair did not perform a full postflight investigation and the cause of
1469-514: 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
1582-566: A loss of fuel flow and pressure that caused the B-2 engine to operate at only 65% thrust. Due to the imbalanced thrust, the Atlas lifted at a slanted angle, which also prevented one of the launcher hold-down arms from retracting properly. Subsequent film review showed that no apparent damage to the missile resulted from either the launcher release or the propellant explosion. The flight control system managed to retain missile stability until T+26 seconds when
1695-637: 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 at Vandenberg AFB , California, under
1808-562: 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. Eight flights of Atlas A occurred during
1921-538: A probable LOX leak. Missile 14D launched from LC-13 on August 11, at which point the Air Force somewhat reluctantly declared the Atlas to be operational as a missile system. On September 9, Missile 12D launched from Vandenberg Air Force Base, marking the first Atlas flight from the West Coast. Eight more D-series ICBM tests were conducted in 1959, as well as two space launches using Atlas D vehicles. Although assorted minor failures and hardware bugs affected these flights,
2034-422: A row followed, some of which tested Nike-Zeus target missiles. On October 2, Missile 4D failed when the vernier engines shut down at T+33 seconds due to an inadvertent closure of the propellant valves. The propellant feed system sent all of the propellant intended for the verniers into the sustainer engine, which was overpressurized beyond its structure limits. The sustainer shut down at T+181 seconds, likely due to
2147-491: A rupture from the excessive pressure level, and the missile fell an estimated 2,300 miles (3,700 km) short of its target. Roll control had been maintained by the booster engines following vernier shutdown, then lost after BECO. Three more Atlas D flights during the year were successful. After the high degree of success achieved in 1962, the flight record of the D-series took a turn for the worse in 1963. The first flight of
2260-491: A sheared retaining bolt in the bell crank pulley system in the right launcher arm. Once again, all other systems in the Atlas functioned well and there were no problems not directly attributable to the launcher malfunction. The flight of 7D resulted in improved maintenance procedures for the launcher equipment at CCAS and use of higher heat steel in the bell crank retaining bolts. Atlas 5D lifted from LC-13 on June 6. The flight went perfectly until booster separation, at which point
2373-536: A sustainer hydraulic failure following BECO and premature engine shutdown, the latter experienced high thrust section temperatures beginning at T+45 seconds, loss of sustainer gimbaling control at T+135 seconds, loss of vernier control at T+195 seconds, and propulsion system shutdown starting at T+233 seconds. Impact occurred east of Hawaii, about 2,300 miles (3,700 km) downrange. Six Atlas Ds were launched in 1967, five ABRES tests and one OV launch. All were successful and Missile 94D, launched from 576-B2 on November 7,
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#17327728239052486-518: 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,
2599-704: The Cold War and intelligence showing the Soviet Union was 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 Soviet R-7 Semyorka in August gave the program new urgency, leading to
2712-579: The Minuteman , 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-derived launch vehicles served a long history as launchers. Even before its ICBM 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 . Mergers led to
2825-516: The "stripped" SAC tests. Missile performance was nominal until T+76 seconds when thrust section temperatures began rising. Pitch stability was lost at T+103 seconds and sustainer hydraulic control failed at T+149 seconds. BECO occurred on time at T+135 seconds, and impact occurred approximately 390 miles (627 km) downrange. This flight resulted in improved installation and stitching for the engine insulation boots. D-series operational tests were suspended for two months while efforts were made to correct
2938-405: 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
3051-403: The Atlas D was originally the G.E. Mk 2 "heat sink" re-entry vehicle (RV) with a W49 thermonuclear weapon , combined weight 3,700 lb (1,680 kg) and yield of 1.44 megatons (Mt). The W-49 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 a W-38 thermonuclear bomb with a yield of 3.75 Mt which
3164-542: 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 at OSTF-2 , Vandenberg AFB Launch Complex 576 and Vandenberg AFB Space Launch Complex 3. Strategic Air Command deployed 13 operational Atlas ICBM squadrons between 1959 and 1962. Each of
3277-401: 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
3390-688: 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 from Cape Canaveral Air Force Station , at either Launch Complex 12 or Launch Complex 14 . The Convair X-12 / SM-65B
3503-536: 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 General Thomas 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
SM-65D Atlas - Misplaced Pages Continue
3616-505: The Cape. This missile utilized a dry start method without any hold-down time at liftoff with no apparent ill effects and all airborne systems performed well aside from an unexplained decrease in B-1 and sustainer thrust a few seconds before BECO. This was attributed to a probable fuel line obstruction. Cameras mounted on the nose cone photographed the spent Atlas after capsule separation. Atlas 90D,
3729-597: The D-series had the full-up Rocketdyne MA-2 propulsion system with 360,000 pounds-force (1,600 kN) of thrust versus the 250,000 pounds-force (1,100 kN) of thrust in the Atlas B/C's engines. 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. The Atlas D testing program began with
3842-480: The OV (Orbiting Vehicle) flights, which were a series of experimental scientific pods. The first attempt using Atlas 172D miscarried when an incorrectly set sustainer PU valve caused fuel depletion and premature SECO. The guidance system did not issue the separation command to the pods, which remained attached to the sustainer section as it reentered the atmosphere and burned up. The second attempt, using Missile 68D on May 28,
3955-492: The Soviet R-5 first 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 called vernier rockets . These provided fine adjustment of velocity and steering after
4068-613: The Spin Motor Rotation Detection System (SMRD). The SMRD had been conceived back in 1958 after the first Atlas B failed in flight due to an inoperative yaw gyro, but was not phased into Atlas vehicles until 1961. Missile 102D had not been upgraded to the newer Type D gyros which had the SMRD, and a quick examination of the Atlas inventory at VAFB found two more missiles with Type B gyros. They were replaced with spare Type D canisters from Project Mercury. After
4181-399: The West Coast hit a series of snags in the following months as well when IOC testing began. Atlas 25D had flown successfully on April 22 from 576B-1, a coffin silo, after delays following the postflight findings from 51D and 48D. The next attempt was 23D on May 6. Following a normal liftoff, control began to fail the moment the pitch and roll sequence began at T+21 seconds. The missile performed
4294-693: The acquisition of the Atlas Centaur line by the United Launch Alliance . Today ULA supports the larger Atlas V , which combines the Centaur upper stage with a new booster. Until 1995, many retired Atlas ICBMs were refurbished and combined with upper stages to launch satellites. 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
4407-485: The attempted launch, then resumed around 45 seconds. At 60 seconds, the Atlas was completely destroyed when the propellant tanks exploded. Postflight analysis of the back-to-back failures found that in each case, the missile had fallen victim to rough combustion in one booster engine, which destroyed the LOX injector head (the injector damage on 51D was more extensive than 48D) and started a thrust section fire. In both missiles,
4520-467: The award of an Army Air Forces research contract to Convair for 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. This MX-774 project was named for the Atlas of Greek mythology and the contractor's parent Atlas Corporation . At the time, the smallest atomic warheads were all larger than the maximum theoretical payloads of
4633-418: The back-to-back pad explosions, it was decided to go back to using a wet start (inert fluid in the engine tubes) on the Atlas rather than the failed experiment of a dry start to ensure smoother engine startup. Atlas 56D (launched on May 20) was the first East Coast launch following 48D and it incorporated the modifications to the launch facilities along with cameras mounted on both launcher heads to look down into
SM-65D Atlas - Misplaced Pages Continue
4746-460: 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 and verniers would operate by themselves. Booster staging took place at roughly two minutes into launch, although
4859-486: The brief flight and the LOX fill/drain valve malfunction was attributed to a breakdown of the butterfly actuator shaft, possibly during the Pre-Flight Readiness Firing a few weeks earlier, so Atlas vehicles starting with Missile 26D would use an actuator made of steel rather than aluminum. The leakage from the fuel fill/drain valve was traced to an improper procedure during the prelaunch countdown and
4972-422: The early years. After watching Atlas Serial 7D explode shortly after its nighttime launch , Mercury astronaut Gus Grissom remarked "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
5085-501: 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 360,000 lb f (1,600 kN ) 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
5198-503: 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 weight balloon 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
5311-601: The final R&D flight of a D-series missile, launched successfully from LC-12 on January 23, 1961. Four operational Atlas D flights from VAFB during the year were successful and the first three flights of 1962 also went without a hitch. Atlas 52D launched from 576-B3 at VAFB on February 21, 1962. Abnormal thrust section temperatures occurred early in the flight, and the sustainer and verniers shut down starting at T+49 seconds. The booster engines experienced thrust decay at T+58 seconds followed by complete loss of thrust at T+68 seconds, and missile breakup five seconds later. This failure
5424-620: The first dry engine start since 48D, as well as the first test of the Mercury ASIS system. The flight was largely successful however an open circuit resulted in the programmer not receiving the VECO discrete from the guidance system at the intended T+300 seconds. A backup command from the programmer performed VECO eight seconds later, consequently the RV landed 18 miles (28 km) further downrange than intended. The next flight, Missile 27D on June 28,
5537-476: The first handful of Atlas E flights as well as space launches. The final test of 1959, Missile 40D on December 19, utilized a "dry" start method (no inert fluid in the engine tubes). This experiment worked without any apparent problems. The first four Atlas flights of 1960, three CCAS and one VAFB launch, were largely successful. On 6D, several malfunctions of the ground guidance system occurred—spurious yaw commands were sent at T+175 seconds and ground guidance lock on
5650-551: 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 its strategic bombers as its primary force and considered Atlas as
5763-573: The first test of the AIG (All Inertial Guidance System) and experienced a 90° roll transient at liftoff. The AIG managed to correct this problem and the missile completed a successful 3,000 miles (4,800 km) lob downrange. With this string of successful Atlas tests, program officials were lulled into a sense of security that rudely ended on March 11 when Atlas 51D lifted from LC-13. The B-1 engine suffered combustion instability which caused loss of thrust within two seconds of liftoff. An explosion ripped apart
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#17327728239055876-419: The fuel management system. When stored, the missile sat atop an elevator. If placed on alert, it was fueled with RP-1 (kerosene) liquid fuel, which could be stored inside the missile for extended periods. If a decision was made to launch, it was fueled with liquid oxygen . Once the liquid oxygen fueling was complete, the elevator raised the missile to the surface for launching. This method of storage allowed
5989-541: 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
6102-435: The hydraulic failure was not determined. One more Atlas D was flown in 1963, an ABRES RV test on December 18, successfully. On April 23, 1964, Missile 263D launched from CCAS LC-12 as part of Project FIRE , a series of suborbital tests designed to verify Apollo command module ablative heat shield material. This was the first suborbital Atlas D flown from the Cape in over three years. Five RV/ Nike-Zeus tests from VAFB during
6215-487: The insulation boots on both missile was also ruled out as a probable cause of the failures. Aside from re-installing the exhaust duct, camera coverage of the flame deflector pit at ignition would also be increased and greater efforts made to ensure that the booster engines were free of contaminants. An added backup accelerometer was added to the RCC sensors in case of a failure. Two launch facilities were now in need of repair. LC-13
6328-471: The launch of Missile 3D from LC-13 on April 14, 1959. Engine startup proceeded normally, but it quickly became apparent that the LOX fill/drain valve had not closed properly. LOX spilled around the base of the thrust section, followed by leakage from the RP-1 fill/drain valve. The propellants then mixed and exploded on the launch stand. Because of the open LOX fill/drain valve, the Atlas's propellant system suffered
6441-457: The launch, the pressure in the LOX tank exceeded the pressure in the RP-1 tank, which reversed the intermediate bulkhead. Two seconds later, the missile exploded. Film review confirmed that the hold-down pin on the right launcher arm failed to retract at liftoff and was jerked from the missile. The resultant force caused a four-inch gap in the B-2 nacelle structure which also damaged low-pressure helium lines. The hold-down pin had not retracted due to
6554-443: The launcher mechanism, all of which were possible causes of the malfunction. On July 29, Missile 11D was launched with a series of modifications designed to correct problems on previous Atlas launches. The flight was mostly successful and booster section separation was performed successfully on a D-series Atlas for the first time, but some difficulties with the hydraulic system occurred due to low engine compartment temperatures caused by
6667-501: 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 at Vandenberg AFB Operational Silo Test Facility , Vandenberg AFB Launch Complex 576 and Vandenberg AFB Space Launch Complex 3 . The SM-65F Atlas , or Atlas-F ,
6780-445: The loss of a heat shield at liftoff. As a consequence, the tank pressurization system mistakenly sensed a drop in tank pressure and began pumping helium into the tanks to raise their pressure level. Pressures in both propellant tanks began rising at T+39 seconds and the missile self-destructed when excessive LOX tank pressure ruptured the intermediate bulkhead at T+71 seconds. While attempting to launch Missile 32D from LC-12 on August 2,
6893-412: The loss of pressure to the LOX feed system ruptured propellant ducting and resulted in an explosion that caused the booster section to rip away from the missile. The Atlas sank backwards through its own trail of fire until the Range Safety destruct command was issued at T+36 seconds. The sustainer and verniers continued operating until missile destruction. All other missile systems had functioned well during
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#17327728239057006-455: 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 delivering Sputnik and Vostok into orbit. The Soyuz rocket is descended from the R-7 and remains in use today. The Convair X-11 / SM-65A Atlas / Atlas A was the first full-scale prototype of
7119-427: The missile was lost for almost two minutes. The missile continued to be unstable in flight for the first 14 seconds of vernier solo phase. Furthermore, an erroneous VECO signal was sent at T+278 seconds but the missile programmer did not act on it due to an apparent open circuit. VECO was intended to take place at T+282 seconds but did not occur for the aforementioned reason and it was instead performed 12 seconds later by
7232-414: The nacelle sections at liftoff, as well as being the first flight from LC-12 in nine months as the pad had suffered major damage in the explosion of Atlas 9C the previous September. This was followed by Atlas 45D, an Agena vehicle used to launch a MIDAS satellite. Missile 54D launched successfully from LC-11, now repaired from the explosion of 48D, on June 11. This was followed by 62D on June 22 which marked
7345-508: The needs of the mission they were performing, but when the Atlas was retired from missile service in 1965, Convair introduced a standardized Atlas vehicle (the SLV-3) for all space missions. Remaining D-series missiles were flown until 1967 for suborbital tests of reentry vehicles and a few space launches. A total of 116 D-series missiles (not including vehicles used for space launches) were flown from 1959 to 1967 with 26 failures. The warhead of
7458-423: The operational control of the 576th 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. The SM-65E Atlas , or Atlas-E , was the first 3-engine operational variant of the Atlas missile, the third engine resulting from splitting
7571-474: The other flight placed the SCORE satellite into orbit. All launches were conducted from Cape Canaveral Air Force Station , at Launch Complexes 11 , 13 and 14 . The SM-65C Atlas , or Atlas C was 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
7684-511: The overall success rate was a major improvement over the first half of the year. Missile 26D on October 29 experienced a premature shutdown of the V-1 vernier when interference from the onboard camera package caused temporary loss of ground guidance lock on the missile. Impact occurred 16 miles (26 km) short of the target point. Because of growing confidence in the Atlas, it was decided to abandon PFRF (Pre-Flight Readiness Firing) tests except for
7797-438: The pipe during ground testing. It could not be determined with certainty if the lack of an exhaust duct had anything to do with the failures, and in any case, camera coverage did not offer any evidence in support of this theory. Nonetheless, it was decided to put the exhaust duct back on the Atlas pads at CCAS in order to comply with the configuration of operational Atlas missile silos, and as a "just in case" measure. Adjustments to
7910-483: 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 to Convair on 23 January 1951 for what
8023-473: The problems experienced during the first few months of 1963. Then 198D carried out a Nike-Zeus test successfully on June 12. Two operational ICBM tests in July–August were also successful. Missile 63D on September 7 suffered a ruptured vernier hydraulic line from aerodynamic heating at T+110 seconds. The sustainer and verniers shut down just prior to BECO and the mission failed. On September 12, 84D experienced
8136-435: 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. Atlas was unusual in its use of balloon tanks for the propellants, made of very thin stainless steel with minimal or no rigid support structures, as already pioneered by
8249-416: The risk that one powerful nuclear warhead could destroy multiple launch sites. 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
8362-410: The roofs protruded above ground level. These units were: The six SM-65F Atlas squadrons 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: The Atlas F's employment was dangerous due to the flammability of
8475-431: The rough combustion cutoff sensor in the B-1 engine failed to operate. On 48D, the rough combustion did not occur in that engine and the lack of RCC cutoff was not a problem (B-1 thrust was terminated instead by the turbopump overspeed sensor). The B-2 RCC sensor operated correctly and terminated thrust before liftoff could be achieved. On 51D, it resulted in the B-1 continuing to operate until the missile lifted, resulting in
8588-522: 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,
8701-551: The successful flight of 64D on March 12, Missile 46D (March 15) failed when the sustainer hydraulic rise-off heat shield broke off. Radiated heat caused the rise-off disconnect valve to fail, resulting in loss of sustainer engine hydraulic fluid. Sustainer and vernier control failed starting at T+83 seconds, but missile stability was retained until BECO at T+137 seconds. After booster jettison, the missile became unstable in flight. SECO occurred at T+145 seconds and impact occurred approximately 500 miles (804 km) downrange. This incident
8814-653: The surface. By 1965, with the second-generation Titan II having 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 lubricant WD-40 found its first use as a corrosion-inhibiting coating for the outer skin of the Atlas missile. 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
8927-472: The sustainer RCC sensor was tripped and an automatic shutdown issued. The sustainer thrust chamber was found to have pinhole leaks in it. It was removed and swapped with a different engine, and 32D was launched successfully seven days later. After this, 66D was launched successfully on August 12 but its RV sank into the ocean and was not recovered. Five more Atlas D tests from CCAS during the year were successful, these were 76D, 79D, 71D, 55D, and 83D. Missile 79D
9040-420: The sustainer engine shut down. 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. Most multistage rockets drop both engines and fuel tanks simultaneously before firing the next stage's engines. However, when the Atlas missile was being developed, there
9153-712: The three missile variants, the Atlas D, E, and F series, were deployed and based in progressively more secure launchers. The number of Atlas intercontinental ballistic missiles in service, at the end of each year: In September 1959 the first operational Atlas ICBM squadron went on operational alert at F.E. Warren AFB , Wyoming equipped with six SM-65D Atlas missiles based in above-ground launchers. Three additional Atlas D squadrons, two near F.E. Warren AFB, Wyoming, and one at Offutt 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: The first site at Warren for
9266-423: The thrust section, followed by structural failure of the propellant tanks, causing the Atlas to fall back onto LC-13 in an enormous fireball. The Atlas went in for a repeat performance on April 8 when Missile 48D, launched from LC-11 and intended as the first closed-loop test of the AIG (All Inertial Guidance System), experienced combustion instability again, this time in the B-2 engine. The first indication of trouble
9379-407: 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 operational ICBM from 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,
9492-462: The year achieved most of their mission goals. The Atlas ICBM program concluded in early 1965, however refurbished missiles continued to be flown from VAFB for various orbital and suborbital mission for years afterward. Six successful RV/ Nike-Zeus flights were carried out using D-series missiles from January to April 1965. On May 22, the second Project FIRE test was performed from the Cape using Missile 264D. During 1965, another new program developed,
9605-551: The year, Missile 39D, lifted from 576-B2 at VABF shortly after midnight on January 25. Beginning at T+86 seconds, the V-2 vernier shut down followed by loss of B-1 engine gimbaling control, telemetry power failure, and booster thrust decay. The sustainer shut down at T+108 seconds and the boosters at T+126 seconds. The missile tumbled, broke up, and impacted about 99 miles (159 km) downrange. Telemetry data revealed abnormally high thrust section temperatures during powered flight; initially
9718-622: Was fuzed for either air burst or contact burst. The Mk 4 RV also deployed penetration aids in the form of mylar balloons 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). SM-65 Atlas 1 × Rocketdyne LR-105 sustainer 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) The SM-65 Atlas
9831-433: Was 389,000 lb f (1,730 kN). Launcher variants of the Atlas often had performance enhancements to the engines. The Atlas missiles A through D used radio guidance : the missile sent information from its inertial system to a ground station by radio, and received course correction information in return. The Atlas E and F had completely autonomous inertial guidance systems. The ground based guidance computer
9944-548: Was a key part of the missile system, until guidance computers were miniaturized enough to be installed inside the missile. Isaac L. Auerbach designed the Burroughs guidance computer for the Atlas ICBM missiles. The Burroughs guidance computer was one of the first transistor computers . It processed 24-bit data using 18-bit instructions. A total of 17 of these ground computers were delivered. These same ground computers
10057-459: Was a major loss of telemetry data at T+109 seconds caused by a power failure, consequently only 13 telemetry measurements remained active for the rest of the flight. Missile 33D (September 29) failed to stage its booster section when the staging electrical disconnect plug pulled out at T+125 seconds; it impacted 1,200 miles (1,900 km) short of the target area. 81D (October 13) failed when the LOX quick disconnect pressure sensor malfunctioned due to
10170-412: Was a near repeat of a failed Atlas-Agena launch three months earlier, and after another Atlas-Agena the following June fell victim to a hydraulic rise-off heat shield loss, the heat shield was redesigned. Check valves were installed on the hydraulic system of Atlas SLVs, although not ICBMs. Missile 193D was launched on March 16, part of the normal operational test series with full telemetry as opposed to
10283-445: Was a pressure surge in the B-2 combustion chamber, followed by unstable thrust, engine shutdown, and an explosion that started a thrust section fire. The B-1 engine then shut down, followed by the sustainer and verniers. Since the propulsion system had not attained sufficient thrust, the launcher hold-down mechanism did not release the missile, which stayed in place and burned on the pad. The thrust section fire slowed down 15 seconds after
10396-483: 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. After the solid-fuel LGM-30 Minuteman had 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
10509-742: Was an even bigger fiasco when a LOX leak during ascent resulted in a thrust section explosion two minutes into launch. Although booster jettison was performed successfully, damage from the explosion resulted in eventual sustainer shutdown and missile self-destruction. Afterwards, it was decided that suborbital flights were insufficient for the OV program and that full orbital tests were needed. There were eleven more Atlas D launches in 1965, ten ABRES/ Nike-Zeus tests and OV 1–2 on October 5. All of these were successful. Fourteen Atlas Ds were launched in 1966, these included ten ABRES and Nike-Zeus tests and two OV launches. Two flights failed. These were respectively 303D on March 4 and 208D on May 3. The former suffered
10622-461: Was completed, Convair rival Martin proposed a solution to the air-starting problem. Their Titan I missile, developed as an Atlas backup, had a conventional two stage design. 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
10735-529: Was conducted with the Mercury astronauts in attendance in order to showcase the vehicle that would take them into orbit, but 64 seconds of flight ended in another explosion, prompting Gus Grissom to remark "Are we really going to get on top of one of those things?" This failure was traced to improper separation of the right launcher hold-down pin, which damaged the B-2 nacelle structure and caused helium pressurization gas to escape during ascent. At 62 seconds into
10848-471: Was deployed in limited numbers as an ICBM due to its radio guidance while the fully operational E and F-series missiles had inertial guidance packages and a different ignition system that allowed faster engine starts. For Mercury, the Atlas D was used to launch four crewed Mercury spacecraft into low Earth orbit . The modified version of the Atlas D used for Project Mercury was designated Atlas LV-3B . Atlas Ds used for space launches were custom-built for
10961-400: 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,
11074-437: Was later used for Atlas-Able , Project Mercury , and other early spacecraft. The warhead of the Atlas D was originally the G.E. Mk 2 "heat sink" re-entry vehicle (RV) with a W49 thermonuclear weapon , combined weight 3,700 lb (1,680 kg) and yield of 1.44 megatons (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
11187-408: Was not connected to the LOX fill/drain valve problem. LC-13 sustained some damage due to the anomalous liftoff of Atlas 3D, this was quickly repaired and preparations began for the launch of Missile 5D. On May 18, Atlas 7D was prepared for a night launch of an RVX-2 reentry vehicle from LC-14, the second attempt to fly one after the launch of a C-series Atlas had miscarried two months earlier. The test
11300-467: 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
11413-504: Was originally planned to be used as the first stage of the Atlas-Able rocket, 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. The SM-65D Atlas , or Atlas D ,
11526-485: Was severely damaged by the fallback of 51D and would not be used again for six months, while damage to LC-11 was less extensive and repairs were completed in only two months. After restoration, LC-13 was converted for the Atlas E and would not host further D-series tests. Attention shifted to LC-12 where Atlas 56D flew over 9,000 miles (14,000 km) with an instrumented nose cone, impacting the Indian Ocean . After
11639-491: Was successful. Missile 60D launched July 2. The vernier start tanks were inadvertently vented and refilled several times during the flight. This resulted in depletion of control helium and decay in propulsion system performance, and so the Mark III Mod 1B reentry vehicle landed some 40 miles (64 km) short of its intended target point. An electrical short in the engine relay control box was suspected. Atlas D tests on
11752-505: Was the final Atlas D flight as ABRES testing would continue using E and F-series missiles. Most Atlas D launches were sub-orbital missile tests; however several were used for other missions, including orbital launches of crewed Mercury , and uncrewed OV1 spacecraft. Two were also used as sounding rockets as part of Project FIRE . A number were also used with upper stages, such as the RM-81 Agena , to launch satellites. The Atlas D
11865-462: 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
11978-407: Was 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 of cryogenic liquid oxygen meant that
12091-556: 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 the Convair Division of General Dynamics at an assembly plant located in Kearny Mesa , San Diego . Development dates to 1946, but over the next few years the project underwent several cancellations and re-starts. The deepening of
12204-411: 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),
12317-504: Was the last test flight from LC-14, which had otherwise been turned over to NASA for Project Mercury but the failure of Mercury-Atlas 1 in July caused a lengthy delay between flights and so LC-14 was temporarily free for use. The most notable flight in this stretch was Atlas 71D on October 13 which carried three mice and other experiments in a biological nose cone which successfully completed a 5,000-mile (8,000 km) lob downrange from LC-11 at
12430-494: Was the second prototype version, introducing the stage and a half system 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 were sub-orbital test flights of the Atlas as an Intercontinental Ballistic Missile , with five successful missions and four failures;
12543-436: 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 the Soviet Union 's 1953 Joe 4 dry fuel thermonuclear weapon test and
12656-506: 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
12769-436: Was traced to a leak in the booster engine gas generator that caused thrust section overheating and loss of engine thrust, and it occurred a mere five hours after John Glenn 's Mercury launch, driving home the point that Atlas was still far from a reliable vehicle. The next flight after 52D was Missile 134D (March 24), witnessed by President Kennedy , who was making a tour of VAFB. Eight successful Atlas D operational flights in
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