PGM-19 Jupiter

Jupiter traces its history ultimately to the PGM-11 Redstone missile, the US's first nuclear ballistic missile. While it was entering service, Wernher von Braun's Army Ballistic Missile Agency (ABMA) team at Redstone Arsenal began to consider an upgraded version using the LR89 rocket engine being developed by Rocketdyne for the Air Force's Atlas missile project. Using the LR89 and adding a second stage would allow the new design to reach 1,000 nautical miles (1,900 km; 1,200 mi),[1] a dramatic improvement over the Redstone's roughly 200 miles (320 km).

As Rocketdyne continued working on the LR89, it appeared that it could be improved to increase thrust over the promised 120,000 pounds-force (530,000 N). In 1954, the Army asked Rocketdyne to provide a similar design with a thrust of 135,000 pounds-force (600,000 N).[2] During this same period, the weight of nuclear warheads was rapidly falling, and by combining this engine with a warhead of 2,000 pounds (910 kg) they could build a single-stage missile able to reach 1,500–1,700 miles (2,400–2,700 km) while being significantly less complicated and easier to handle in the field than a two-stage model. This engine was continually upgraded, ultimately reaching 150,000 pounds-force (670,000 N).[1] This last model, known to the Army as the NAA-150-200, became much better known by its Rocketdyne model number, S-3.[3]

Admiral Arleigh Burke is credited with breaking the Navy out of its moribund ways, and pressing for development of the SLBM.

Around the same time, the US Navy was looking for ways to join the nuclear club, and had been focusing mostly on cruise missiles and similar systems. Some consideration had been given to the use of ballistic missiles on ships, but Admiral Hyman Rickover, "father" of the nuclear submarine, was skeptical that this could be done, and was worried it would take up funding needed elsewhere.[4] Another skeptic of missiles was the Chief of Naval Operations, Robert B. Carney.[5]

Lower-ranking Navy officials became increasingly interested when the Army and Air Force began serious development of their long-range missiles. In an attempt to bypass high-ranking Navy officials, who remained uninterested in the concept, the Navy liaison to the Killian Committee championed the cause. The Committee took up the concept, and in September 1955 released a report calling for the development of a sea-based missile system.[5]

The Navy's interest in missiles had been greatly increased with the August 1955 appointment of Admiral Arleigh Burke to replace Carney. Burke was convinced the Navy had to get into the missile field as rapidly as possible, and was well aware that the Air Force would oppose any such endeavor. Instead, he approached the Army, and found that the proposed Jupiter fit the range goals needed by the Navy.[5]

The issue of who would be given the go-ahead to build an IRBM by this time had reached the Joint Chiefs of Staff (JCS), who proved unable to reach a decision. This forced the Secretary of Defense Charles Erwin Wilson to move ahead without an official recommendation from the military. He saw the Navy interest as a reasonable argument to continue the Army project in any event, and on 8 November 1955 approved both programs. The Air Force would develop IRBM No. 1, or SM-75 (for "strategic missile"), the Army would develop their design as IRBM No. 2 or SM-78. The Navy would develop systems to launch the Army missile from ships and, later, submarines.[5][6] BuShips completed a conceptual design that would take a Maritime Administration type C4-S-1a hull and convert it into a Jupiter missile launch ship, which was given the hull symbols YAG-58 then EAG-155; the conversion would later be canceled.[7]

The requirement for shipboard storage and launching dictated the size and shape of the Jupiter. The original Army design was 92 feet (28 m) long and 95 inches (2,400 mm) in diameter. The Navy stated they were not interested in anything longer than 50 feet (15 m). The ABMA team responded by increasing the diameter to 105 inches (2,700 mm). This precluded it from being carried aboard contemporary cargo aircraft, limiting it to sea and road. Even with this change, they were unable to reduce its length enough to suit the Navy. They suggested that they begin with a 60 foot (18 m) long version and then scale it down as improvements in the engines were worked into the design. This was rejected, and after briefly considering a 55 foot (17 m) version, finally settled on the 58 foot (18 m) version.[8]

On 2 December 1955, the secretaries of the Army and Navy publicly announced the dual Army–Navy program to create a land- and sea-based MRBM. In April 1956, as part of a widespread effort to assign names to various missile projects, the Army's effort was given the name "Jupiter" and the Air Force's became "Thor".[1]

Redstone provided an accuracy of 300 metres (980 ft) at its maximum range, which, when combined with its large warhead, allowed it to attack hard targets like protected airbases, bridges, command and control sites, as well as other strategic targets like railway marshaling yards and pre-attack concentration areas. This was in keeping with the Army's view of nuclear weapons, which was in effect more powerful artillery. They saw the weapons as part of a large-scale battle in Europe, in which both sides would use nuclear weapons during a limited war that did not include the use of strategic weapons on each other's cities. In that case, "if wars were to be kept limited, such weapons would have to be capable of hitting only tactical targets." This approach saw the support of a number of influential theorists, notably Henry Kissinger, and was seized on as a uniquely Army mission.[9]

The original goal for the new longer-range design was to match Redstone's accuracy at the Jupiter's much-extended range. That is, if Redstone could reach 300 m at 200 miles, the new design would provide a circular error probable on the order of 7 kilometres (4.3 mi). As development continued, it became clear the ABMA team, under the direction of Fritz Mueller, could improve on that. This led to a period in which "The Army would lay down a particular accuracy, and wait for our arguments whether it was possible. We had to promise a lot, but were fortunate."[10]

This process ultimately delivered a superior design intended to provide 0.5 miles (0.80 km) accuracy at the full range, an order of magnitude better than Redstone and four times better than the best INS designs being used by the Air Force. The system was so accurate that a number of observers expressed their skepticism about the Army's goals, with the WSEG suggesting they were hopelessly optimistic.[10]

The Air Force was dead set against Jupiter. They argued that nuclear weapons were not simply new artillery, and that their employment would immediately trigger a response that might result in a strategic exchange. This would especially be true if the Army launched a long-range weapon like Jupiter, which could reach cities in the Soviet Union and could not immediately be distinguished as attacking a military or civilian target. They suggested that any such launch would trigger a strategic response, and as such, the Army should not be given any long-range weapons.[10]

However, as von Braun's team went from success to success, and with Atlas still years from operational deployment, it was clear that Jupiter represented a threat to the Air Force's desired hegemony over strategic forces. This led to them starting their own MRBM program Thor, in spite of having repeatedly dismissed the medium-range role in the past.[11] The fighting between the Army and Air Force grew through 1955 and 1956 until practically every missile system the Army was involved in was being attacked in the press.[12]

The Navy's Polaris had range similar to Jupiter.

The Navy was concerned from the start about Jupiter's cryogenic propellants, but at the time there was no other option. Given the size and weight of contemporary nuclear weapons, only a large liquid-fuel rocket engine provided the energy needed to meet the Navy's range goal of launching from safe areas in the Atlantic Ocean. They justified the risk thus:

We were prepared to take the chance that we might lose a submarine or two through accidental explosions. But, then, there are some of us who enjoy, or at lease [sic] are acclimated to, the idea of risking our lives."[13]

All of this changed radically in the summer of 1956, when Project Nobska brought together leading scientists to consider antisubmarine warfare. As part of this workshop, Edward Teller stated that by 1963 a 1 megaton warhead would be reduced to only 600 pounds (270 kg).[14] Rocketry experts at the same meeting suggested that an intermediate-range weapon carrying one of these weapons could be built using solid propellant. Even in this case, the missile would be much smaller than Jupiter; Jupiter was expected to weigh 160,000 pounds (73,000 kg), while estimates of a solid-fuel missile with similar range were closer to 30,000 pounds (14,000 kg), along with a similar reduction in size which was of paramount importance to a submarine design.[15]

The Navy announced their desire to develop their own missile that summer, initially under the name Jupiter-S. After intensive follow-up studies, the Navy withdrew from the Jupiter program in December 1956. This was officially announced by the Army in January 1957.[16] In its place, the Navy began development of what was then known as the Fleet Ballistic Missile Program, and the missile was later renamed Polaris, their first submarine-launched ballistic missile (SLBM).[17] Rickover, one of the few remaining skeptics, was won over by pointing out that a properly designed submarine was needed specifically for this role, and he would be called upon to produce it. Rickover was from that point on a staunch ally of the program.[18]

Secretary of Defence Neil McElroy visits the Jupiter prototype assembly line at ABMA. ABMA built the test articles, while Chrysler built the production models.

On 4 October 1957, the Soviets successfully launched Sputnik I from their R-7 Semyorka ICBM. The US was aware of these efforts and had already talked to the press about it, suggesting that if the Soviets launched a satellite first it would be no big deal.[19] To their surprise, the press exploded in rage over the affair. Having spent over a decade working on similar missiles, like Atlas, the fact that the Soviets could beat them was a serious blow, and prompted a deep review of the ongoing programs.[20]

One problem noted from the start was that the internecine fighting between the Army and Air Force was leading to significant duplication of effort, with little to show for it. The Department of Defense responded by creating the Advanced Research Projects Agency (ARPA), whose initial mission was to look over all of the ongoing projects and select ones based solely on their technical merits.[21]

At the same time, the fighting had begun to have negative political effects. In a 26 November 1956 memorandum, recently appointed US Secretary of Defense Charles Erwin Wilson attempted to end the fighting. His solution was to limit the Army to weapons with 200-mile (320 km) range, and those involved in surface-to-air defense to only 100 miles (160 km).[22] The memo also placed limits on Army air operations, severely limiting the weight of the aircraft it was allowed to operate. To some degree this simply formalized what had largely already been the case in practice, but Jupiter fell outside the range limits and the Army was forced to hand them to the Air Force.[23]

The Air Force, of course, had no interest in taking over a weapon system they had long argued was not needed. However, ARPA's studies clearly showed it was an excellent system, and as it was ready to enter production, any Air Force thoughts about canceling it were immediately quashed. New orders for 32 prototypes and 62 operational missiles were soon placed, bringing the total number of Jupiters to be built to 94. The first, hand-built at ABMA, would be delivered by the end of FY57, and the first production models from Chrysler's Michigan Ordnance Missile Plant near Warren, Michigan between FY58 and FY61.[21]

A primary complaint about Jupiter was that the design's shorter range placed it within relatively easy striking distance of Soviet weapons, both missiles and aircraft. Thor, based in the UK, would likely have more warning of an impending attack.[lower-alpha 1] This is precisely the reason that the Army spent considerable effort on making Jupiter mobile, in order to make surprise attacks difficult without prior aerial reconnaissance missions.[10]

However, in November 1958, the Air Force decided Jupiter would be launched from fixed emplacements. Army General Maxwell Taylor argued this was done deliberately, noting that:

...a mobile missile needs Army-type troops to move, emplace, protect and fire it... a decision to organize mobile ballistic missile units would in logic have led to transferring the operational use of the weapon back to the Army – where it should have been all the time.[10]

To offset the possibility of air attack, the systems were upgraded to allow a launch within 15 minutes of a launch order.[21]

In 1954 Test Laboratory director Karl Heimburg began construction of the Static Test Stand for Redstone testing. This was still under construction when it was re-purposed for Jupiter, and finally completed in January 1957.[25] A Jupiter was installed in the stand that month, and fired for the first time on 12 February 1957. This almost ended in disaster when a small explosion went off in the liquid oxygen (LOX) pump, and as the missile sat there the LOX boiled off and threatened to burst the tanks. The day was saved when the foreman, Paul Kennedy, ran to the missile and connected a pressure line to drain the oxygen buildup in the tank. The problem was later traced to the lubricant used in the pump, which tended to burst into flames in contact with LOX. A new lubricant was introduced, along with a series of changes to the test stand to help retain control in these situations.[26]

Kurt Debus had led the construction of launch pads for Redstone missiles at Cape Canaveral, Florida, building the twin LC-5 and LC-6 pads about 500 feet (150 m) apart with a common blockhouse located 300 feet (91 m) away between the two. Redstone testing moved to these pads from the smaller LC-4 on 20 April 1955, with the launch of the seventh Redstone from LC-6. Envisioning an extended test program, a second set of similar pads began construction in 1956, LC-26 A and B; the only major difference was the blockhouse was located slightly further away, about 400 feet (120 m). In late 1957 a set of parallel railway tracks running just east of the pads was added, allowing an A-frame gantry to be rolled to any of the four pads.[27]

Jupiters were delivered to the Cape strapped to wheeled trailers and flown to the Cape's "Skid Strip" on C-124s. They were then moved to Hangar R at the Cape Industrial Area where the nose cone was mated with the missile, and electrical checkout was performed. It was then moved on the trailer to the pads, about 3.5 miles (5.6 km) south, where they were lifted to vertical by a crane on the movable gantry. Just to the north of the launch area was the Air Force's LC-17 for Thor, and LC-18 used for Thor and the Navy's Vanguard. After the Army's head start, the Air Force had since caught up and attempted its first Thor launch on 26 January 1957, which ended with the missile exploding on the launch pad.[28]

Jupiter test flights commenced with the launch of AM-1A (ABMA Missile 1A) on 1 March 1957 from LC-5. This missile was equipped with the lower-thrust interim engine. The vehicle performed well until past 50 seconds into launch when control started to fail, leading to breakup at T+73 seconds. It was deduced that turbopump exhaust was sucked up by the partial vacuum in the area behind the missile and began to burn in the tail section. The heat burned through the control wiring, so extra insulation was added there on future flights. An identical AM-1B was quickly readied and launched on 26 April. AM-1B's flight went entirely according to plan up to T+70 seconds when the missile started becoming unstable in flight and finally broke up at T+93 seconds. The failure was deduced to have been the result of propellant slosh due to bending modes induced by the steering maneuvers needed to perform the flight trajectory. The solution to this problem involved testing several types of baffles in a Jupiter center section until discovering a suitable type for both the LOX and fuel tanks.[28]

The third Jupiter, also numbered AM-1, was quickly equipped with the baffles and launched on 31 May, slightly over a month after AM-1B, traveling a full 1,247 nautical miles (2,309 km; 1,435 mi) downrange. This version had a slightly improved S-3 engine with 139,000 pounds-force (620,000 N) thrust. AM-2 flew from LC-26A on 28 August, and successfully tested the separation of the rocket body from the reentry vehicle section before splashing down at 1,460 nautical miles (2,700 km; 1,680 mi). AM-3 flew from LC-26B on 23 October, including the ablative heat shield and the new ST-90 INS. This test flew a planned distance of 1,100 nautical miles (2,000 km; 1,300 mi).[28]

AM-3A launched on 26 November and all went according to plan until T+101 seconds when engine thrust abruptly terminated. The missile broke up at T+232 seconds. On 18 December, AM-4 lost thrust T+117 seconds and fell into the ocean 149 nautical miles (276 km; 171 mi) downrange. These failures were traced to an inadequate turbopump design that resulted in a string of failures in the Jupiter, Thor, and Atlas programs, all of which used a variant of the same Rocketdyne engine. Testing then paused for five months while Rocketdyne came up with a number of fixes and the Army retrofitted all its Jupiters with the redesigned pumps.[28] In spite of these failures, Jupiter was declared operational on 15 January 1958.

Taking the time to also fully rate the engine to 150,000 lbf, the new engine was first flown on AM-5 on 18 May 1958 from LC-26B, reaching a planned 1,247 nautical miles (2,309 km; 1,435 mi). AM-5 also carried the real nose cone design, which separated from the rocket body, spun up the warhead, and separated to allow the warhead to continue on its own. The warhead section was equipped with a parachute and was recovered by the Navy some 28 nautical miles (52 km; 32 mi) from its predicted splashdown point.[28]

AM-6B included both the production nose cone and the ST-90 INS during its launch from LC-26B on 17 July 1958. This time the Navy recovered it only 1.5 nautical miles (2.8 km; 1.7 mi) from its planned splash down point 1,241 nautical miles (2,298 km; 1,428 mi) downrange. AM-7 flew 1,207 nautical miles (2,235 km; 1,389 mi) on 27 August, testing a new solid fuel rocket for spinup, replacing the older hydrogen peroxide model. AM-9 was launched on 10 October, the first Jupiter to carry the fully functional turbine exhaust roll control system. The flight failed however; a pinhole leak in the thrust transducer area started a thrust section fire and loss of vehicle control. The Range Safety Officer destroyed the missile at T+49 seconds. [28]

Afterwards, there was only one more failure in the Jupiter program, AM-23 on 15 September 1959, which developed a leak in a nitrogen bottle that led to depressurization of the RP-1 tank and almost immediate loss of control at liftoff. The missile wobbled from side to side and the RP-1 tank began to break apart starting at T+7 seconds. The Jupiter flipped upside down, dumping out the contents of the RP-1 tank, followed by total vehicle breakup at T+13 seconds, just before the Range Safety Officer could issue the flight termination command. Flying debris struck and damaged a Juno II on the adjacent LC-5. This particular launch was carrying a biological nose cone with mice and other specimens (which did not survive).[29]

Through the early 1960s, a number of Jupiters were launched by the forces of other countries, as well as the Air Force, as part of ongoing combat training. The last launch of this sort was by the Italian Air Force, CM-106, which took place from LC-26B on 23 January 1963.[30]

Jupiter AM-18 pre-launch

Able and Baker, the first two primates who survived space travel aboard Jupiter AM-18.

Jupiter missiles were used in a series of suborbital biological test flights. On 13 December 1958, Jupiter AM-13 was launched from Cape Canaveral, Florida with a Navy-trained South American squirrel monkey named Gordo on board. The nose cone recovery parachute failed to operate and Gordo did not survive the flight. Telemetry data sent back during the flight showed that the monkey survived the 10 g (100 m/s²) of launch, eight minutes of weightlessness and 40 g (390 m/s²) of reentry at 10,000 mph (4.5 km/s). The nose cone sank 1,302 nautical miles (2,411 km) downrange from Cape Canaveral and was not recovered.

Another biological flight was launched on 28 May 1959. Aboard Jupiter AM-18 were a seven-pound (3.2 kg) American-born rhesus monkey, Able, and an 11-ounce (310 g) South American squirrel monkey, Baker. The monkeys rode in the nose cone of the missile to an altitude of 300 miles (480 km) and a distance of 1,500 miles (2,400 km) down the Atlantic Missile Range from Cape Canaveral.[31] They withstood accelerations of 38 g and were weightless for about nine minutes. A top speed of 10,000 mph (4.5 km/s) was reached during their 16-minute flight.

After splashdown the Jupiter nosecone carrying Able and Baker was recovered by the seagoing tug USS Kiowa (ATF-72). The monkeys survived the flight in good condition. Able died four days after the flight from a reaction to anesthesia while undergoing surgery to remove an infected medical electrode. Baker lived for many years after the flight, finally succumbing to kidney failure on 29 November 1984 at the United States Space and Rocket Center in Huntsville, Alabama.

United States

Redstone Arsenal, Huntsville, Alabama 34°37′58.11″N 86°39′56.40″W

White Sands Missile Range, New Mexico 32°52′47.45″N 106°20′43.64″W

Republic of Italy

Deployment locations for Jupiter missiles in Italy from 1961 to 1963

Headquarters: Gioia del Colle Air Base, the launch sites (built in a triangular configuration) were in the direct vicinity of the villages Acquaviva delle Fonti, Altamura (two sites), Gioia del Colle, Gravina in Puglia, Laterza, Mottola, Spinazzola, Irsina and Matera.

Training Pad 40°47′6.74″N 16°55′33.5″E

Squadron 1

Site 1 40°44′24.59″N 16°55′58.83″E

Site 3 40°35′42.00″N 16°51′33.00″E

Site 4 40°48′47.05″N 16°22′53.08″E

Site 5 40°45′32.75″N 16°22′53.08″E

Site 7 40°57′43.98″N 16°10′54.66″E

Squadron 2

Site 2 40°40′42.00″N 17°6′12.03″E

Site 6 40°58′6.10″N 16°30′22.73″E

Site 8 40°42′14.98″N 16°8′28.42″E

Site 9 40°55′23.40″N 16°48′28.54″E

Site 10 40°34′59.77″N 16°35′43.26″E

Turkish Republic

Headquarters: Çiğli Air Base

Training Pad 38°31′17.32″N 27°1′3.89″E

Site 1 38°42′26.68″N 26°53′4.13″E

Site 2 38°42′23.76″N 27°53′57.66″E

Site 3 38°50′37.66″N 27°02′55.58″E

Site 4 38°44′15.13″N 27°24′51.46″E

Site 5 38°47′30.73″N 27°42′28.94″E

Juno II launch vehicle derived from Jupiter IRBM mobile missile.

The Juno II was a four-stage rocket derived from the Jupiter IRBM. It was used for 10 satellite launches, six of which failed. It launched Pioneer 3 (a partial success), Pioneer 4, Explorer 7, Explorer 8, and Explorer 11.

• Juno II total length: 24.0 m
• Orbit payload to 200 km: 41 kg
• Escape velocity payload: 6 kg
• First launch date: 6 December 1958
• Last launch date: 24 May 1961

• Bilstein, Roger (1996). "Stages to Saturn". NASA History Office.
• Healy, Roy (18 December 1958). Development of the Rocket Engine for the Jupiter Missile (PDF) (Technical report). Rocketdyne.
• Kyle, Ed (14 August 2011). "King of Gods: The Jupiter Missile Story". Space Launch Report.
• Mackenzie, Donald (1993). Inventing Accuracy, a Historical Sociology of Nuclear Missile Guidance. MIT Press.
• Neufeld, Jacob (1990). The development of ballistic missiles in the United States Air Force 1945–1960. DIANE Publishing. ISBN 9781428992993.
• Walker, James; Bernstein, Lewis; Lang, Sharon (2003). Seize the High Ground: The U. S. Army in Space and Missile Defense. Washington, D.C.: Center of Military History. ISBN 9780160723087. OCLC 57711369. Retrieved 13 May 2013.