Jupiter on Trailer Offloaded from C-124

Jupiter missiles were delivered to Cape Canaveral’s “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 Laboratory’s 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 both races.

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 rocket’s 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 years before.

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.

Missile 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 successes.

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 command.

Jupiter Liftoffs Created Sheets of Flame on the Flat Pads

1958’s 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 speed.

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 many flights.

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.

Author:

by Ed Kyle, Updated 7/09/2011