From Missiles to Space

JPL’s entry into the space program came through an alliance with the Army Ballistic Missile Agency (ABMA) on the Jupiter intermediate-range ballistic missile program. In 1955 and 1956, JPL worked with ABMA on a backup radio guidance system and the reentry test vehicle for Jupiter. The radio guidance work gave JPL the funding and opportunity to improve radio communica­tions between ground systems and flight vehicles, later evolving into JPL’s Deep Space Network. The reentry test vehicle was a spacecraft in all but name. ABMA and JPL performed reentry test flights between September 1956 and August 1957. The Army Ordnance commander, Gen. John Medaris, ordered the remaining rocket hardware to be put into storage, hoping to launch a spacecraft.34 For the moment, Medaris had to wait; the navy’s Vanguard was to launch the first U. S. spacecraft. However, the failure of Vanguard’s first test flight in December 1957 paved the way for the army.35

With public pressure building in the wake of Sputnik, President Eisenhower gave the army the green light to unleash Wernher von Braun’s ABMA team and Pickering’s engineers at JPL. Pickering seized the opportunity. By partici­pating in the space race, Pickering could return JPL to engineering research instead of the drudgery of weapon systems development. In a brief discussion immediately preceding a meeting to assign responsibilities for the orbital at­tempt, Pickering convinced Medaris to assign JPL the spacecraft and tracking network. JPL engineers quickly designed a high-speed stage, eventually des­ignated Explorer 1, consisting of clusters of Sergeant solid motors and a cylin­drical can that contained telemetry equipment and scientific experiments.36

JPL engineers used processes developed on Sergeant and the reentry test vehicle. By the summer of 1956, ABMA and JPL had tested rocket motors in small vacuum chambers to ensure that they would operate in space. Engineers expanded these tests to examine the Explorer spacecraft’s capacity to with­stand large temperature variations in a vacuum, such as it would encounter when in the Sun or in the shade of the Earth. JPL engineers replaced vac­uum tubes with transistors, repackaged electronic components, and tested the entire package with random-vibration tests. In addition, they used re­dundancy to increase the chances for success if one component failed. JPL’s ground telemetry systems were ready. When in January 1958 the ABMA’s Jupiter rose from Cape Canaveral, JPL’s Explorer 1 spacecraft and ground sys­tems functioned perfectly, returning scientific data leading to the discovery of the Van Allen radiation belts and confirming that micrometeorites were not a problem.37

ABMA and JPL followed Explorer 1 with a series of spacecraft in the Ex­plorer and Pioneer series. Because the primary goal was to compete in a prestige race with the Soviets, engineers hurriedly lashed together existing technologies to jury-rig space missions. Explorer 2-Explorer 6, Pioneer 3, and Pioneer 4 had a mixed record, with several successes and several failures. Be­cause of the urgency of the space race, neither the army nor Congress ques­tioned this record. Spacecraft failures occurred out of sight, unlike spectacu­lar rocket explosions and their unpleasant publicity. JPL engineers, used to the army mentality of firing many test rounds, thought of these early space­craft as test rounds and were not overly concerned with achieving a perfect record. They rushed into space and reverted to the earlier Corporal mentality of small project groups using informal methods.38

Despite the exploits of ABMA and JPL, the army lost its battle against the air force and the new NASA for a significant space role. On January 1, 1959, President Eisenhower transferred JPL to NASA, and the ABMA soon there­after.39

For NASA, JPL proposed a new program for lunar and planetary explo­ration known as Vega. Vega was to develop a third-stage rocket and spacecraft similar to Explorer’s high-speed stage and payload. Its spacecraft design was far more complex than Explorer’s because it needed to operate for months in transit to the Moon, Venus, or Mars. The Vega spacecraft was to feature important new technologies, including solar panels, three-axis attitude stabi­lization, and a flight computer. Just as after Corporal, when JPL managers and engineers planned the Sergeant missile as a ‘‘systems job,’’ JPL engineers and managers carefully planned for Vega, succeeding the hastily built Explorer and Pioneer spacecraft.40

JPL Director Pickering selected Clifford Cummings as Vega project direc­tor. Cummings had worked under Pickering on Corporal and Sergeant, de­veloping analytic tools. He believed that better maintenance required better analysis of training programs and costs, supply networks and logistics, test equipment, and vehicle design. Vocal and outspoken, Cummings believed that scientists and engineers could work out difficult problems through work­ing groups and a thorough test program.41

Cummings and his deputy, James Burke, organized Vega’s test program using lessons from Corporal, Sergeant, and Explorer. He and Burke planned a mockup spacecraft for structural and mechanical tests as well as an engineer­ing model for environmental and electrical tests. Only after the engineering model passed these tests would JPL build the flight spacecraft. Vega featured a new ‘‘systems test’’ that would simulate the flight sequence and events with all of the spacecraft subsystems working together. Engineers were to record test results on specialized forms for later analysis. After engineers assembled and tested the spacecraft in this manner, they would then perform the same tests in a large vacuum chamber, then in a vibration test facility, and finally at Cape Canaveral prior to launch.42

Plans for Vega did not come to fruition because NASA Administrator Keith Glennan canceled the program in December 1959 to avoid duplication of the air force’s previously secret Agena upper stage. Glennan decided to use the air force’s Atlas-Agena for NASA’s early missions instead of Vega. Never again would JPL work on the rocket designs upon which it had made its reputation. In place of Vega, JPL acquired NASA’s robotic lunar and planetary missions, which became the Ranger, Surveyor, and Mariner programs. Time spent plan­ning for Vega was not completely wasted, as its design studies and test plans carried over to Ranger.43