KING OF GODS: The Jupiter Missile Story
Fourth in a Series Reviewing Jupiter's Place in Space
by Ed Kyle, Updated 7/09/2011
Jupiter Takes Flight
Jupiter on Trailer Offloaded from C-124
Jupiter missiles were delivered to Cape Canaverals
Skid Strip by C-124 Globemaster II air cargo transports. Upon
arrival, the missiles, which were shipped already mounted on wheeled transporters, would
be towed to Hanger R in the Cape Industrial Area for processing. There, the aft unit and
nose cone would be installed and the vehicle would be powered up for testing.
After check out, the vehicle would be towed to the
launch pad, located about 5.5 km southeast of the Hanger. At the pad, the gantry crane
would lift the R&D missile onto a relatively simple ring stand. No flame trenches or
ducts were used. Instead, a small thrust deflector fixed to the base of the ring stand
spread flames from the engine in all directions.
The ABMA launch facilities were spare and
labor-intensive compared to later pads at the Cape. Propellants were dispensed to the
missile directly from tanker trucks at the pad. Crews had to manually connect and
disconnect propellant fill lines. Photos show numerous workers at the pad during LOX
loading, vapors enveloping them, with ladders propped up against missiles to provide
worker access to fill/drain connections. Hoses ran across the concrete pad apron.
Since propellant lines fed through the gantry tower, the tower would continue to be
parked at and partially enclosing the vehicle until late in the countdown process.
Once the gantry pulled away from the missile, an
umbilical mast, or for early launches only a set of umbilical cables suspended from a
lanyard, remained to provide connections to the aft unit on top of the missile. The
lanyard would pull the cable connections free from Jupiter just after engine start was
initiated. Another umbilical connected to the base of the vehicle.
Jupiter AM-1A Prelaunch Activities. Note Technician
Working Beneath Fully Loaded Missile. LC 17/18 Towers Visible in Background.
The Army launch pads were adjacent to the U.S. Air Force
Thor pads at LC 17 and LC 18, and the U.S. Naval Research Laboratorys Project
Vanguard pad at LC 18. It was among these virtually shoulder-to-shoulder pads that the
interservice missile and space "races" played out. Thor and Jupiter battled for
first IRBM honors. Vanguard and Jupiter C raced to be first into orbit. The Army would win
The race began on January 26, 1957, when Thor 101, the first Thor, exploded at liftoff
right on its launch pad.
Jupiter flew next. Missile AM-1A (ABMA Missile 1A), equipped with an interim 61.24 tonne
force (135,000 lb) thrust S-3 engine, on autopilot rather than inertial guidance, lifted
off for the first time on March 1, 1957. The rocket rose cleanly from LC 5, pitched
properly downrange, and accelerated into the late afternoon sky. AM-1A followed its
planned trajectory until, suddenly, about 74 seconds after liftoff as it approached an
altitude of 14.6 km, it turned hard left and began breaking up.
Investigation showed that hot gases from the fuel rich turbopump exhaust had become
entrained and recirculated at the rockets base. There, the gases were ignited by the
main exhaust plume, creating excessive heat in the tail section, causing the failure.
Before the second flight, ABMA improved heat shielding at the base of the missile to
mitigate the effects of base heating. On April 26, 1957, the second Jupiter, missile
AM-1B, a functional twin of AB-1A, lifted off from LC 5. This time Jupiter flew higher
(27.2 km) and longer (93 seconds), but still failed when sloshing propellants caused loss
of flight control.
ABMA hurried to solve the slosh problem. A
railroad tank car was used to test internal baffle configurations. Baffles were soon
added to both LOX and RP-1 tanks.
Redesigned Aft Section, Circular Flame Curtain Still to be
Installed. Note Swivel Turbopump Exhaust on Right.
By the time the third Jupiter arrived at LC 5, two more
Thors had failed. Thor 102 had flown for 35 seconds in April 1957 before being
accidentally destroyed by range safety. Thor 103 had blown up on its pad when loaded with
propellant awaiting launch, with several minutes still on the countdown clock, in May. The
Air Force and its contractors were learning hard lessons that the Army team had learned
It was left to that third Jupiter missile, number AM-1, to make history on May 31, 1957
from LC 5 when it successfully flew what was essentially a full range test, traveling
2,309 kilometers (1,247 nautical miles, or 1,435 statute miles) downrange. The range was
shorter than 2,778 kilometers (1,500 nautical miles) because the missile, like the first
two Jupiters, was not equipped with a separable warhead. AM-1 was powered by a 63.05 tonne
force (139,000 pound) thrust S-3 series engine that burned for 163 seconds.
Jupiter made two more successful flights, on August 28 and October 23, 1957, from LC 26A
and B, respectively. Missile AM-2 performed the first separation of the body unit from the
thrust unit during the August test. The body unit, not equipped with a heat shield,
reached 2,704 kilometer (1,460 nautical mile) range.
An ablative heat shield nose was flown to 2,037
kilometer (1,100 nautical mile) range during the October test on missile AM-3, the first
night launch of a Jupiter missile. Again the body unit separated from the thrust
unit and a nose cone separation was not planned. AM-3 also performed an open
loop test of the ST-90 inertial guidance system.
The next two Jupiter flights failed after both suffered turbopump failures. AM-3A exploded
101 seconds after its November 26 launch from LC 26B. AM-4 lost power 117 seconds after
rising from the same pad on December 18, 1957, and fell into the Atlantic only 149
nautical miles downrange.
AM-5 at LC 26B
Jupiter flight testing paused for five months while
Rocketdyne dealt with turbopump issues and ABMA grew busy launching Explorer I and II. An
investigation found that gear box lubricant oil was breaking down in the vacuum of space.
Engineers added a check valve to a drain line to maintain positive pressure, preventing
the break down.
By the end of 1957, Jupiter had flown seven times and recorded three successes. After a
troubled start, Thor had flown nine times and, finally hitting its stride, achieved five
Jupiter AM-5 flew a successful 2,309 km (1,247 nautical mile) range flight from LC 26B on
May 18, 1958. This landmark flight was powered by a 68 tonne force (150,000 lb) thrust
S-3D engine for the first time. It also carried the first tactical nose cone, which
performed the first nose cone separation and reentry. The nose cone parachuted into the
Atlantic and was successfully recovered by the U.S. Navy, though it landed about 52 km (28
nautical miles) short of its planned target.
Jupiter AM-6B performed the first ST-90 full range inertial guidance test from LC 26B on
July 17, 1958. Again the nose cone was recovered. The precise aim of the guidance system
helped, dropping the nose cone within 2.8 km (1.5 nautical miles) of the target, which was
some 2,298 km (1,241 nautical miles) downrange.
Jupiter AM-7 flew 2,235 km (1,207 nautical miles) on August 27, 1958 from LC 26A. The
inertial guidance flight carried the first solid propellant vernier and spin motors on its
aft unit and the first live fusing system for its inert warhead. Prior flights had used a
liquid hydrogen peroxide monopropellant vernier.
Jupiter AM-9 suffered a tail fire and had to be destroyed 49 seconds after liftoff on
October 9, 1958. A pin-hole propellant leak near the thrust transducer was the likely
cause. The flight used the first active swiveled turbopump exhaust roll control and was
equipped with the first squib nozzle blow off system for terminating vernier thrust on
Liftoffs Created Sheets of Flame on the Flat Pads
1958s final Jupiter missile flight was the
NASA-supported scientific mission named Bioflight 1. Jupiter AM-13
carried a 0.5 kg squirrel monkey named Gordo, in a specially designed capsule
fit within the spinning nose cone, on the suborbital test flight from LC 26B on December
13, 1958. The missile flew to an altitude of 483 km, traveled 2,411 km (1,302 nautical
miles) downrange and came down near its target.
Unfortunately, recovery crews were unable to save
Gordo. A temporary cable between the aft unit and thrust unit had not been
removed prior to launch, causing an interaction at separation that caused the
aft unit to wobble for a moment. This may or may not have contributed to subsequent
failure of the nose cone recovery parachute deployment. Telemetry showed that
Gordo survived the 10 g of launch, eight minutes of weightlessness and 40 g of
reentry deceleration, only to perish when the nose cone impacted the Atlantic at high
AM-13 was the 12th Jupiter missile test and the 7th
success. By the end of 1958, Douglas, pushing hard on its highly prioritized U.S.
Air Force IRBM program, had launched 23 Thor missiles and scored 14 successes, along with
an additional 6 Thor-Ables, used to test reentry vehicles and to launch Pioneer probes,
with three successes. Thor had caught Jupiter through sheer expenditure of labor and
money, but Jupiter had been able to accomplish as many development milestones with half as
One week prior to Bioflight 1, a modified Jupiter,
Missile AM-11 fitted with a spinning upper stage motor cluster in place of the tactical
nose cone, lifted off from LC-5. This rocket, the first of its type named Juno
II, was not aiming for a target down the Atlantic Missile Range. It was aiming
for the Moon.
History of the Jupiter Missile System, James Grimwood,
Frances Stroud, U.S. Army Ordnance Missile Command, July 27, 1962.
Thanks to Art Lebron for First Two Images. Other
images ABMA/NASA/U.S. Air Force.
Next: Juno II