Lunar Impact

The NASA History of Project Ranger

R. Cargill Hall, Paul Dickson

• Publisher: Dover Publications
• Year: 2013
• ISBN:
  9780486139715
• Topic: Physical Sciences
• Subtopic: Astronomy & Astrophysics

America's first successful attempt at unmanned lunar exploration, Project Ranger culminated in close-up television images of the moon's surface. Sponsored by NASA and executed by the Jet Propulsion Lab, the project ran from 1959 to 1965 and produced management techniques, flight operating procedures, and technology employed by later space missions.
This official NASA publication presents the complete history of the nine Project Ranger missions. Author R. Cargill Hall, the historian of the Jet Propulsion Laboratory, offers an authoritative account of the evolution and operations of the continuing program of unmanned exploration of deep space. More than 100 photographs depict key personnel and illustrate rockets and a range of other equipment. Nine helpful appendixes feature a fascinating array of source documents.

Part I

THE ORIGINAL RANGER

Chapter One

THE ORIGINS OF RANGER

“FROM what they say they have put one small ball in the air,” President Dwight D. Eisenhower declared at his news conference on October 9, 1957, adding, “at this moment you [don‘t] have to fear the intelligence aspects of this.”¹ But despite the Presidential assurance, the Soviet satellite, Sputnik 1, launched a few days earlier as part of the world-wide scientific program of the International Geophysical Year,² had shattered confidence in American technical preeminence. In the wake of the Soviet triumph, many Americans concluded that the United States must undertake a vigorous space program of its own.

A MOON FLIGHT PROPOSAL

Shortly after the launch of Sputnik 1, William H. Pickering,³ the Director of the Jet Propulsion Laboratory in Pasadena, California, advanced a novel idea. The Soviet Union had merely hurled a satellite into orbit around the earth. Pickering, along with a number of his staff at the Laboratory, wanted the United States to meet the Russian space challenge by sending a spacecraft to the moon.

The Jet Propulsion Laboratory, or JPL, had been pursuing exotic projects in its field for years. Begun in 1936 under the auspices of the Guggenheim Aeronautical Laboratory of the California Institute of Technology, it had originated as a student rocket research project when the scientific community generally regarded rockets as an indulgence best left to students. In 1940 the Caltech rocket experimenters acquired an Army Air Corps contract and built facilities in northwestern Pasadena, at the foot of the San Gabriel Mountains in the Arroyo Seco wash. There they developed the first solid- and liquid-propellant rocket motors for jet-assisted takeoff of military aircraft. The enterprise was reorganized and named the Jet Propulsion Laboratory when, in 1944, after the advent of the German V-2 rocket, U.S. Army Ordnance awarded Caltech a contract to develop tactical ballistic missiles.⁴

Continuing to work for the Army into the 1950s, JPL engineers and scientists designed and developed the liquid-propellant WAC Corporal sounding rocket, the Corporal tactical missile, and the solid-propellant Sergeant tactical missile system. The Laboratory also pioneered in the development of radio telemetry and of various radio and inertial guidance systems for the Army’s Redstone rocket arsenal in Huntsville, Alabama, where the director of research was Wernher von Braun. All the while, JPL, whose facilities were owned by the government, remained an Army establishment under the contract management of Caltech. Its posture and atmosphere were free-wheeling, academic, and innovative. By 1957 Director Pickering, a professor on the Institute faculty, presided over a considerable laboratory complex nestled in the Arroyo Seco and populated by some 2,000 employees.

Like the Laboratory, Pickering, too, had come a long way from his beginnings—the small fishing village of Havelock, New Zealand, where he had attended the same primary school as the famed pioneer in nuclear physics, Ernest Rutherford. Displaying an aptitude for mathematics and science, Pickering was sent to high school in Wellington, the capital of New Zealand, where he built and operated wireless sets and performed extracurricular chemistry experiments in a classmate’s cellar. Lured to Caltech in 1929 by an uncle in Los Angeles, he embarked on a career in electrical engineering, but by 1936 emerged with a Ph.D. in physics and an appointment to the Caltech faculty. Applying his capabilities in electrical engineering to one of the central research subjects in the physics of the day, he joined Robert A. Millikan and H. Victor Neher in research on the absorption properties of primary cosmic rays using instrumented balloon sondes.

During World War II Pickering organized and taught electronics courses at Caltech for military personnel, which brought him into contact with the Radiation Laboratory at MIT, including its director, the physicist Lee A. DuBridge. In 1944 he went out to JPL to design and develop telemetering and instrumentation equipment for the long-range missiles. When DuBridge was named the new president of Caltech in 1946, Pickering was busy perfecting the telemetry system to be used in the Laboratory’s rocket research vehicles.⁵ He preferred to work at the forefront of applied engineering research and development. Appointed the Director of JPL in 1954, he began turning that preference into Laboratory policy (Figure 1 ). By the time of Sputnik, JPL was equipped to contribute to the nation’s first response to the Soviet space challenge: the orbiting of the Explorer 1 satellite. Pickering’s laboratory supplied the solid-propellant upper stages of the launch rocket, furnished the space-to-ground communications equipment and instrumentation for the satellite, and helped integrate into it the radiation monitoring experiment of James Van Allen.

But Pickering, spare, intense, reserved, and in a quiet way implacable, was determined to mount a JPL program of lunar flights. To his mind, and to DuBridge’s, such flights were an appropriate entrant in the emerging Soviet-American space race. Like rockets a generation before, lunar flights might once have been a subject fit only for science fiction, but now they were on the reachable frontier of engineering science, exactly the frontier where Pickering wanted JPL to be. Using the technology available, the United States could launch a simple, spin-stabilized vehicle, similar to the Explorer satellite in design, on reasonably short notice, possibly as early as June 1958. Three weeks after the launch of Sputnik 1, Pickering, with DuBridge’s support, had ready a JPL moon flight proposal. Designated “Project Red Socks,” the proposal declared it “imperative” for the nation to “regain its stature in the eyes of the world by producing a significant technological advance over the Soviet Union” in rocketry and space flight. Pickering wanted the Department of Defense to approve JPL’s embarking immediately on a series of nine rocket flights to the moon.⁶

Fig. 1. JPL Director William Pickering in 1954

Pickering and DuBridge got nowhere with their Red Socks lunar proposal in the Defense Department⁷ until early 1958, when it came under the consideration of the new Advanced Research Projects Agency, or ARPA, whose responsibilities temporarily included the direction of all U.S. space projects. The new ARPA director and former General Electric Company executive, Roy Johnson, was eager “to surpass the Soviet Union in any way possible,”⁸ and he could choose to do it from a host of unsolicited flight proposals. In fact, “after we had been in business a short time,” his deputy Rear Admiral John E. Clark recalled, “it seemed to me that everybody in the country had come in with a proposal except Fanny Farmer Candy, and I expected them at any minute.”⁹ Because the Soviet Union had not yet launched a rocket to the moon, an unmanned lunar program appeared to be the most promising approach to “beat the Russians” in space.

With the President’s approval, on March 27, 1958, Secretary of Defense Neil McElroy announced that ARPA’s space program would advance space flight technology and “determine our capability of exploring space in the vicinity of the moon, to obtain useful data concerning the moon, and to provide a close look at the moon.”¹⁰ Conducted as part of the United States contribution to the International Geophysical Year, the lunar project would consist of three Air Force launches using modified Thor ballistic missiles with liquid-propellant Vanguard upper stages, followed by two Army launches using modified Jupiter-C missiles and JPL solid-propellant upper stages. JPL was to design the Army’s lunar probe and arrange for the necessary instrumentation and tracking. ARPA directed the Air Force to launch its lunar probes “as soon as possible consistent with the requirement that a minimal amount of useful data concerning the moon be obtained.”¹¹

THE FIRST LUNAR FLIGHTS

The ARPA lunar program approved in March 1958, generally known as the “Pioneer program,” offered five flight opportunities, three for the Air Force and two for the Army. Space Technology Laboratories, the West Coast-based contract manager of the Air Force ballistic missile program, which was assigned responsibility for the technical direction of the Air Force lunar missions, also furnished the spacecraft. Shaped like two truncated cones back-to-back (Figure 2), the fiberglass lunar probe, 74 centimeters (29 inches) in diameter and 46 centimeters (18 inches) long, carried 17.5 kilograms (39 pounds) of scientific instruments, battery power, transmitter and antenna, and a retrorocket system designed to slow the vehicle into lunar orbit.

In keeping with the original ARPA requirements, this spacecraft also supported a small facsimile television system. But engineers at the Space Technology Laboratories had barely completed the spacecraft design in June 1958 when the discovery of the first Van Allen radiation belt stimulated scientists to issue urgent requests for more, improved experiments to measure charged particles in near-earth space. Though retaining the television camera, the firm’s researchers directed the rest of the scientific instrumentation toward fields and particles in space: a magnetometer to measure the magnetic fields of the earth and moon, and a micrometeoroid impact counter to survey the flux and energy of micrometeoroids between these two bodies. To obtain more information on the distribution of radiation in space, they installed a Van Allen-supplied ion chamber on flight two, and augmented it with a proportional counter from the University of Chicago on the third flight.¹² The final report summarized the extent of this thoroughgoing change: “To the maximum extent possible, within the weight and power restrictions, experiments were designed to obtain scientific measurement of the environment in cislunar space.”¹³

Fig. 2. STL Pioneer Lunar Probe (Courtesy TRW)

The first lunar flight of the Air Force Thor-Able launch vehicle rose from Cape Canaveral on August 17 and ended 77 seconds later in a pyrotechnic display above the beach. This “catastrophic failure,” the investigative report declared, was caused when a turbo pump bearing seized in the main-stage rocket engine.¹⁴ The embarrassing flight went officially unnamed by the Air Force, though informally it became known as “Pioneer O.” After corrective measures had been taken with the main-stage engine, the Air Force launched the second vehicle on October 11, 1958. This time a guidance system error caused an early shutdown of the second-stage engine. Upon completion of burning of the third-stage engine, the velocity attained was less than that required to escape the earth’s gravity. The spacecraft separated properly from its third-stage rocket and continued to ascend to an altitude of 115,000 kilometers (71,700 miles), about one-third the distance to the moon, before falling back to be incinerated in the earth’s upper atmosphere.

This second flight, promptly christened Pioneer 1, though of course precluding photography of the moon, did yield good scientific data from the magnetometer and micrometeoroid detector. The ionization chamber measuring radiation intensity developed a leak; much of its radiation information, at first unintelligible, was subsequently unscrambled and recovered.¹⁵ The last flight in the Air Force series, Pioneer 2, followed on November 8. The third-stage engine failed to ignite, and the vehicle rose only 1,550 kilometers (963 miles) before falling back to earth. It returned no significant experimental data.¹⁶

While the Air Force lunar flights were underway, JPL completed design of the Army’s lunar probe, which would also separate from its fourth-stage rocket, and of the necessary instrumentation and tracking facilities. The JPL design called for a cone-shaped, fiberglass instrument package, 51 centimeters (20 inches) long and 25.5 centimeters (10 inches) in diameter at its base (Figure 3).¹⁷ The scientific experiment consisted of a small camera weighing 1.5 kilograms (3.3 pounds), capable of photographing the moon. The lunar image on 35-millimeter film was to be developed by a wet process, scanned by optical means, transmitted from the spacecraft via telemetry code, and reconstructed on earth by facsimile methods at a ground receiving station. Snapped at closest approach, 24,000 kilometers (15,000 miles) from the moon’s surface, the picture would provide a resolution of 32 kilometers (20 miles).¹⁸ Flight plans called for the first of the Army-NASA lunar probes to carry and test a special shutter-trigger mechanism: photoelectric cells would “see” the moon at a preset distance, and trip the shutter. The second flight would then carry the complete camera on a looping trajectory around the moon, with the aim of returning one good photograph of the far side. On the first of these two probes, two Geiger-Muller tubes furnished by Van Allen to measure charged radiation particles in space were added in place of the camera.

Data returned by United States IGY satellites Explorers 1, 3, and 4, meantime, revealed more details of the high-intensity radiation surrounding the earth. In the absence of heavy shielding, such radiation could fog the film in the photographic experiment planned for the Army lunar probe. Consequently, the Army canceled the camera experiment and, in August 1958, JPL began to develop a small, lightweight, slow-scan television camera and magnetic-tape recording and transmission system, all of which were to be functionally insensitive to radiation in space, in time for flight in early 1959.¹⁹

On December 6, 1958, the Army launched the ...