LUNAR IMPACT: A History of Project Ranger

Part I. The Original Ranger


In 1962 planetary scientists around, the country eagerly awaited the flights of the Block II vehicles. Rangers 3, 4, and 5 would land seismometers on the moon, analyze the chemical composition of the surface material, and transmit close-up pictures. The results could profoundly influence long–held theories concerning the moon's structure and evolution. At JPL, project engineers expectantly looked forward to demonstrating the proper functioning of Ranger's ground and space flight machinery–including the crucial midcourse correction maneuver. 1 And the upcoming Ranger flights had their national and international ramifications. Ranger 3 and her sister spacecraft were widely interpreted as "advance scouts for the manned expeditions..." as vital preliminary links in a still larger chain of lunar affairs. 2 Ranger offered the nation a chance to advance from challenger to champion in exploring the moon, the hope of restoring international confidence in the supremacy of Yankee know-how, and the opportunity to bring to an end a succession of nine humiliating American moon flight failures. 3 Americans concerned over the Soviet space lead awaited "The US. Moon Shots" of 1962.


In July 1961, JPL engineers assembled Ranger 3, the first of the Block II lunar machines. Early in November they completed system testing, calibration, and checkout of the heat-sterilized, lightweight spacecraft and its scientific instruments. On November 15, NASA accepted the vehicle. Leaving Pasadena in a specially fitted, air-conditioned van for southern Florida, Ranger 3 began its journey to the moon. It arrived at Cape Canaveral on November 20, the day after the Ranger 2 mission ended ignominiously in the earth's upper atmosphere. At the Aeronutronic Division of the Ford Motor Company in Newport Beach, California, meantime, other engineers worked double shifts in efforts to confirm the flightworthiness of the lunar seismometer capsule in time for the scheduled flight in January 1962.

Ranger 3’s lunar target had already been selected. Lighting conditions at the lunar surface were suitable for photography from a spacecraft in a near-vertical descent for a few days during the moon's third-quarter phase. In the first month of the new year, the usable days were January 22 through January 26. The seismometer, though unaffected by photometric considerations, had to be directed to a place on the moon's surface where the earth appeared high enough above the lunar horizon to permit radio contact between the tracking stations and the seismometer's transmitter. Certain locations were affected more severely by lunar libration, or rocking of the moon in its orbit, which varied the earth-moon angle, and could cause the loss of as much as half of the data from the seismorneter. In a compromise among the experimenters for both instruments, the point of impact selected was just south of the lunar equator and west of the lunar prime meridian, on the eastern rim of Oceanus Procellarum-the Ocean of Storms.

William Kirhofer and Victor Clarke in the JPL Trajectory Group worked out the lunar transfer trajectories from Agena second bum to the completion of Ranger's mission at the selected point of impact. The trajectories strictly limited the permissible time for countdowns. Ranger's launch window on each of the available days extended from 3:30 to 4:45 p.m. EST. During that period the earth would rotate into a position for the flight to begin. Sixty-six hours after launch, the earth would also be in a position for the Goldstone tracking station to view the spacecraft at lunar impact. By using variable launch azimuths and coasting times between first and second bum of the Agena in earth orbit, and by taking into account the motions and the gravitational attractions of the earth, moon, and sun, flight engineers could employ Ranger's midcourse engine to compensate for minor variations in the flight path, and thus bring the spacecraft to the moon at the specified time and location. 4

With so many conditions to be satisfied, however, just to achieve the lunar trajectories could be considered a major accomplishment. Ranger 3 was to be directed to a point in space where the moon would be three days later. If the spacecraft were to hit the moon, not to mention the target of interest to the planetary scientists, it would have to be delivered onto its ballistic path in space at an altitude of 193 kilometers (120 miles) above the earth and a velocity of 10,959 ± 7 meters per second (24,500 ± 16 miles per hour). Only slight deviations in the Agena's altitude, direction of travel, or accumulated velocity would prevent Ranger from being able to correct its flight path sufficiently to hit the moon at all (Figure 51).


Fig. 51. Lunar Launch Constraints

Agena B 6003 and Atlas 121D, the launch vehicle components that would place Ranger 3 onto its trajectory to the moon, arrived at Cape Canaveral in mid December. After inspection and tests conducted by personnel from Lockheed and General Dynamics-Astronautics, these vehicles were erected at Launch Complex 12, preparatory to the performance of integrated tests with the lunar spacecraft The entire ensemble completed the Joint Flight Acceptance Test on January 5, whereupon engineers removed the spacecraft to Hangar AE to begin final preparations for launch. 5

In the two weeks remaining before the first launch attempt, Ranger 3 was disassembled, and its components were inspected for the last time. Reassembled in the newly constructed Explosive Safe Area in Hangar AE in mid-January, the seismometer capsule and retromotor, both balanced and checked out, were installed together with Ranger's fueled midcourse engine, flight battery, and radar altimeter. After successfully completing final systems tests on January 18, engineers returned Ranger 3 to Launch Complex 12 and remounted it on the Agena. They were satisfied that the spacecraft and launch vehicle were flight ready (Figure 52).


Fig. 52. Technicians Make Final Adjustments to Ranger 3 at Cape Canaveral

Their own plans and procedures established, Ranger's experimenters were also ready. JPL Space Sciences Chief Hibbs had appointed Harold W. Washburn as the Ranger Project Scientist for the Block II missions. Washbum, the conduit between the project engineers and the experimenters, would coordinate their activities during the lunar flights. In meetings at JPL and NASA in preceding weeks, experimenters had acknowledged that closeup pictures of the moon's surface would contain the greatest popular appeal. The television experimenters, "recognizing the great interest of the public," agreed to release representative photographs to the news media immediately upon receipt. Later, after processing was completed, copies of all of the photographs were to be issued to approved lists of scientists and scientific groups. 6 Whatever the popular attraction of any pictorial returns, however, Washburn, Hibbs, and Burke evaluated the potential contribution to knowledge of each individual instrument and determined the standing each should have during flight operations. Wherever priorities could not be avoided in an emergency, they gave first preference to data from the gamma-ray spectrometer, second preference to the television camera, and third preference to the seismometer. 7

Walter Larkin's Goldstone tracking station in California had installed special equipment to receive the telemetry from the gamma-ray spectrometer and seismometer experiments. A trailer containing RCA equipment to record Ranger's television signals was also at the site and connected to the station. Eberhardt Rechtin and his team of telecommunications specialists in the Deep Space Network began to check out each of the radio tracking stations in the Deep Space Network on January 10, finishing the operational readiness tests involving all of the stations on January 19. The JPL space flight control center in Pasadena transmitted, received, and processed simulated tracking and telemetry data in the proper sequence and format. 8 The Deep Space Network was also prepared to support the project scientists and engineers.

All of Ranger 3’s preflight activities continued on schedule through January 19, when launch crews began the task of pumping kerosene fuel aboard Atlas 121D. Upon completing the fueling task, however, they discovered a leak in the bulkhead between the fuel tank and the liquid oxygen tank. While the fuel was pumped back out of the Atlas, project officials hurriedly conferred. It was launch vehicle problems all over again, only this time with Atlas instead of Agena. The situation appeared to preclude the launch of Ranger 3 during January; the Atlas would have to be returned to its hangar for repairs, and the launch postponed until late February.

Air Force and Atlas contractor personnel, however, urged another, more novel course of action. The repair, they suggested, might be made on the pad from inside the rocket-in time for a launch attempt on January 26. In any case, nothing would be lost, and a month could be saved. Burke approved the proposal. In the next few days engineers disconnected the center engine of the Atlas and lowered it into the flame pit beneath Launch Complex 12. A wooden framework was prefabricated, passed through the engine hole at the base of the Atlas fuel tank, and assembled inside the 3-meter (10-foot) diameter tank by men wearing oxygen packs and masks. Working twenty-four hours a day, the Atlas field crew removed the ruptured bulkhead and restored the launch vehicle to a flight-ready condition for the launch attempt on January 26. 9

While General Dynamics-Astronautics engineers clambered around inside the Atlas, JPL crews finished last-minute preparations for Ranger 3, still mounted inside the nose fairing high atop the Agena. They performed final sterilization between January 23 and 24, bathing the spacecraft in a toxic concentration of ethylene oxide gas for eleven hours and purging it afterward with dry nitrogen passed through a sterile filter. 10 Whenever launched and whatever the outcome, this United States machine would carry a minimum amount of earth bugs into space.

But after the ingenious repair of the Atlas and the time spent in final preparations, on January 26 only one hour and 15 minutes of the launch window remained. When the countdown began at 10:45 am EST, everyone knew that any further delay would postpone the mission.


The countdown went flawlessly. At 3:30 p.m. EST, Ranger 3 rose gracefully into a warm, sunlit Florida sky. Spectators gathered there to witness the daytime flight, and bathers on the beaches for miles around joined project engineers in shouting approval. The United States was on its way to the moon (Figure 53).


Fig. 53. Launch of Ranger 3

Yet the vehicle had not left sight before the telemetry monitors knew that something was awry. Commands generated by the Cape computer and radioed to Atlas 121D went unacknowledged-the rocket’s airborne radio guidance system had failed. The Atlas continued to ascend under control of its auto pilot, using internal program information to establish the sequence of flight events. Unable to command shutdown of the engines at the precise times, NASA and JPL officials could expect a deviation in the planned lunar trajectory. The project officers drove across the Cape to the JPL command post at Hangar AE to await further word from the tracking stations downrange, including the Department of Defense ship between Antigua and Ascension Islands. Within twenty minutes data from these stations indicated that the Agena B had separated properly and its engine had burned once, placing the vehicle in an earth parking orbit. Unable to respond to commands from the ground, however, the Atlas had flown higher and faster than planned. Like its predecessors, Ranger 3 was being accelerated into an unplanned orbit.

The crew of the mobile tracking antenna in South Africa waited to receive the values for the actual trajectory from Cape Canaveral. But communications equipment in Florida malfunctioned, preventing the transmission. Using the time of launch and planned trajectory figures, the station acquired Ranger 3 as it rose over the horizon five minutes ahead of schedule, at 3:55 p.m. EST. The Agena B had completed its second bum, although a further variation in the trajectory, later traced to an error in the Agena's flight program, had also occurred.

Within an hour, the radio tracking station at Woomera confirmed these facts. Fired into space with excessive speed, Ranger would pass ahead of and below the moon at a distance of some 32,000 kilometers (20,000 miles). This kind of miss-distance exceeded the corrective capabilities of Ranger's midcourse engine; Ranger 3 would continue into orbit around the sun. Yet Burke and other project engineers had some consolations. The spacecraft separated properly from the Agena, acquired the sun and earth, deployed its high-gain antenna, switched to solar power, and turned on the gamma-ray spectrometer experiment. Despite problems with the launch vehicle, Ranger 3 was working. Except for an unexplained drop in the signal strength of the low-gain antenna, NASA and JPL controlled an operating Ranger on a deep space trajectory. 11

Confident in this knowledge, Burke left the Cape for the West Coast. That same evening, tired and disheveled, he assumed command of the space flight operations at the JPL control center. Together with his assistant Gordon Kautz and Flight Test Director Marshall Johnson, Burke considered what they might do with a spacecraft destined to hurtle wide of the moon. The deep space trajectory of Ranger 3 might have supported the earlier experiments of sky scientists handsomely, but it was of little value to the planetary experiments actually aboard the spacecraft. Since the lunar seismometer could not be deposited on the, moon, it could never listen for a moonquake. The gamma-ray spectrometer, busily establishing the radiation background generated by the spacecraft, would be limited to measuring for sky science the gamma-ray flux in interplanetary space. Among the lunar experiments, only the television camera might be used to good effect. If Ranger 3 could be positioned properly using a terminal maneuver, pictures of the moon, including portions of the backside hidden to view ftom the earth, would be a distinct possibility.

Evaluating these and other matters, Burke, Kautz, and Wolfe decided that Ranger 3 would be used to test all of the spacecraft functions, including the midcourse and terminal maneuvers, and to obtain television pictures of the moon. Although they would have liked to launch the lunar seismometer capsule and ignite its retrorocket as a test, that course of action was not possible. The capsule system had been intentionally designed to separate from Ranger only on command from the radar altimeter. And since Ranger 3 would pass the moon at a great distance, the altimeter could not detect that celestial object and trigger the ejection. 12

A few hours later, in the early morning of January 27, the Spacecraft Command Group finished preparing the three stored commands defining Ranger's midcourse correction maneuver. Sent to Goldstone, the commands were radioed to Ranger 3 by the tracking station. The spacecraft confirmed their receipt and stored them in the register of its electronic brain, the central computer and sequencer. A final command to initiate the maneuver was transmitted at 2:00 am PST. Ranger turned through the desired angles in roll and pitch, and the midcourse rocket engine fired at the appointed moment and for the proper duration. The attitude control system then reacquired the sun and the earth, returning the spacecraft to its former attitude, and normal cruise operations resumed. Cheers and handshakes were the order of the day in the JPL control center for the first time an unmanned spacecraft had altered its course in flight upon commands from the earth (Figure 54).


Fig. 54. Ranger Block II Midcourse Maneuver Sequence

But as the sky lightened in the east above the San Gabriel Mountains, postmaneuver tracking information relayed from the Woomera and Johannesburg stations revealed Ranger 3 to be moving in a direction that was the mirror image of the one anticipated. Members of the Spacecraft Data Analysis Team pored over the available data in attempts to determine the cause of the unorthodox course change. During the period of about thirty hours remaining between the midcourse and terminal maneuvers, they analyzed the fault. A sign had been inverted between the digital maneuver code used in the ground computer at JPL and the spacecraft computer. While preflight tests had checked the magnitude and polarity of the commands, they had not checked their meaning. In any case, the flight path had been changed in such a way that Ranger would fly nearest the moon at the end of the second period during which the spacecraft was in view of the Goldstone tracking station, instead of earlier in the period as planned. That change limited the time for picture taking.

Even though headed on an erroneous course, Ranger 3 continued otherwise to perform flawlessly. Shortly after the midcourse maneuver, the gamma-ray spectrometer was extended 1.8 meters (6 feet) by its gas-actuated telescoping boom. To the delight of experimenters James Arnold and Albert Metzger, the instrument began returning data on the gamma-rays in interplanetary space. The next day, on January 28, as Ranger neared the moon, in the period termed "lunar encounter," additional commands caused the protective cover over the television camera lens to swing aside, and that instrument began to warm up.

At JPL, members of the Spacecraft Command Group prepared new coded commands for the terminal maneuver-this time with the erroneous digital sign reversed (Figure 55). At least the spacecraft could be turned so that the television camera pointed directly at the moon. Beginning at 8:29 am PST, Goldstone transmitted the commands to the spacecraft. The command to initiate the terminal maneuver followed one hour later. Ranger 3 began to pitch in the proper direction, confirming the diagnosis of a sign inversion. Midway through its prescribed turns, however, Ranger's signal strength began to waver, momentarily dropping below the threshold of the sensitive receivers at Goldstone. Ranger's high-gain antenna, which pivoted and continued to operate during this maneuver, was no longer pointing directly at the earth as it should. The spacecraft was out of control.


Fig. 55. Ranger Block 11 Terminal Maneuver Sequence

Ranger's central computer and sequencer had failed, immobilizing the earth and sun sensors. Under the control of its gyroscopes alone, the spacecraft continued to turn. Goldstone intermittently reacquired the radio signal, but its strength fluctuated greatly as Ranger 3 drifted aimlessly about its axis in space. The television camera, nevertheless, began sending back pictures as it already had been programmed to do. Because the high-gain antenna remained pointed away from the earth, the video signal was extremely weak and obscured by noise. When developed, the pictures showed that the camera system had operated; reference crosses on the lens were clearly observable, illuminated by light apparently reflected from the spacecraft superstructure. But the moon was nowhere to be seen.

Unaware at first of the true cause of Ranger's situation in space, the controllers transmitted urgent backup commands to the spacecraft. Now brainless, Ranger 3 could not process them. The unresponsive spacecraft swept past the moon six hours later at a distance of 37,000 kilometers (23,000 miles), on its way into solar orbit. Intermittent tracking continued for three more days, until January 31, when the attitude control gas ran out and the spacecraft began to tumble. The mission was over. 13


There were hardly enough hours in the succeeding weeks for engineers to accomplish all that needed doing before the launch of Ranger 4. Final system tests were completed on schedule at JPL, and on February 26 the spacecraft arrived at its Cape Canaveral hangar. There it was readied for the series of preflight tests to meet the launch period from April 21 through 26. Other members of the Project Office in Pasadena, meanwhile, undertook an investigation of the flight of Ranger 3, since the success of Ranger 4 obviously hinged on identifying and resolving the technical failures of its predecessor.

On February 8 Burke sent the preliminary findings of the postflight investigation to Oran Nicks at Headquarters. Burke itemized the malfunctions and the corrective measures to be taken for future Ranger flight. The Atlas bulkhead rupture during fueling, as well as the airborne guidance failure in flight, the breakdown in communications between Cape Canaveral and the deep space tracking stations, and the reversal of sips in the digital command codes prepared for Ranger spacecraft would be precluded by new tests and revised procedures. The exact causes of the drop in signal strength in Ranger 3 Is low-gain antenna and the failure of its central computer and sequencer during the terminal maneuver remained question marks. Attempts to duplicate these malfunctions with the Ranger proof test model in simulated flight situations proved inconclusive. Minor revisions were made to both pieces of equipment on the "basis of possible causes." New components added to Ranger's electronic brain, Nicks learned, would not be heat sterilized. 14 Heat sterilization was suspected to have contributed to the failure of the central computer and sequencer.

One further difficulty, mentioned but briefly in the preliminary findings, caused special concern to Burke and the project office. Ranger 3 had provided the first opportunity for ground controllers to compute a deep space orbit, generate commands for a midcourse maneuver, and direct the flight of a spacecraft. Although JPL personnel who served on the control teams reported administratively to Johnson and Burke for the flight operations, they worked "on loan" from the technical divisions at the Laboratory. During the flight a number of the division chiefs, anxious to know how the respective spacecraft subsystems were performing, had entered the control areas. Too often they had interfered with the flight operations by demanding time from and issuing orders to their functional subordinates-orders that conflicted with the planned flight routine. Several of the experimenters had also bypassed Ranger Project Scientist Harold Washburn to deal directly with Flight Test Director Marshall Johnson, further complicating the operations. 15

Burke and Johnson pressed for changes in procedure and in the arrangement of space inside the temporary control center in Building 125 at JPL. With the support of Laboratory leaders in the weeks preceding the launch of Ranger 4, they added glass partitions in the control center, insulating control team members from others nearby, and prepared lists of personnel authorized to be in the various control areas, with entry to be monitored by security guards. Finally, they redefined the authority and responsibilities of the various participants. The Flight Test Director, not the division chiefs, would direct the control teams and the spacecraft during a mission.

Because the spacecraft had performed well until the central computer and sequencer failed at lunar encounter, the project engineers considered the capabilities of the machine demonstrated. be next flight, they were sure, would remove all remaining doubts. Even the experimenters who had yet to realize their scientific objectives shared in that confidence. Having nearly succeeded, "we were sure," James Arnold observed, that one or both of the remaining capsule missions "would give us good data." 16 Their optimism found its way into the news media. The U.S. would shortly have pictures of the moon and more. Scientists and engineers in Pasadena "were less than disconsolate. They were pleased that most of the complex mechanisms...had functioned perfect in response to radio signals over distances of hundreds of thousands of miles." 17 Ranger 3 after all was the most sophisticated spacecraft yet launched by the United States, "as crammed with electronic tricks as a barrel of transistor radios," Time magazine enthused. 18 Another flight, or maybe two, would see America on the moon.

But not everyone shared the confidence evident among project engineers and scientists. Dissent surfaced within the engineering fraternity, particularly that segment affiliated with the aerospace industry that preferred Air Force contracting methods. The aerospace trade journal Aviation Week suggested that the Ranger system, developed for NASA "in-house" by a university-affiliated laboratory, was too ambitious and not designed conservatively enough. The flight of Ranger 3 had "greatly aggravated the continuing controversy over reliability vs performance." The NASA-JPL pursuit of "very high performance" from Ranger had been at the expense of its reliable operation. Improving the reliability of the spacecraft-by adding backup systems, for example-called for increased weight. And more weight on a spacecraft as crammed with electronic tricks as Ranger was surely impossible. 19 Ranger, the journal implied, would have been handled differently for NASA by American industry.

The implications of prior launch vehicle failures, however, and the miscalculated weight of the Ranger spacecraft that precluded redundant engineering features, were nowhere evident in the reporting. Addressing himself to these and other questions raised by the flight of Ranger 3, on February 7, JPL Director Pickering publicly summarized the results of the postflight investigation at a news conference. He explained the thinking behind the original Ranger design and sequential pattern of flights: "Because of the great complexity of the project necessarily great if we are to advance in this space flight area-three Ranger [lunar] shots were planned to achieve a mission success." Furthermore, while the most recent mission was not a complete "success, or even a moon impact, I can safely say we face the next shot...with a great deal more knowledge and confidence because of the facts learned from Ranger 3" 20 The project, Pickering assured its budding critics, was in good hands, and making excellent progress.


At Cape Canaveral in March, project engineers subjected Ranger 4 to the prescribed series of system tests. The launch vehicle, Atlas 133D/Agena B6004, began preflight tests at the same time; all of the Ranger elements moved steadily toward a flight on April 21, the first day of the prescribed lunar launch period. With minor adjustments in the lunar trajectory, the experimenters targeted Ranger 4 to rough-land its seismometer on the moon at nearly the same point as that selected for Ranger 3: just south of the lunar equator on the eastern rim of the Ocean of Storms. 21

By April 20, all of the preflight inspections and tests had been finished. 22 When Ranger 4 was placed atop the Atlas-Agena launch vehicle at Launch Complex 12, the precautions and changes adopted after the Right of Ranger 3 had been followed to the letter. The seismometer capsule sported a new saw-tooth paint pattern designed better to maintain thermal balance during its flight to the moon. Terminal sterilization of the spacecraft with ethylene-oxide gas had been completed. The tracking stations in the deep space network were checked out, and for the first time the 25-meter (84-foot) antenna at Johannesburg was equipped with a transmitter making it possible to command as well as track Ranger 4 from South Africa. Four tracking ships instead of one had been detailed to support the flight of Ranger 4, deployed from the Caribbean to Ascension bland. Once again everything was ready (Figure 56)


Fig. 56. Technicians Prepare Ranger 4 for Launch at Cape Canaveral

Air Force and NASA officials postponed the countdown on April 21 one day to permit another launch at Cape Canaveral; with fair weather forecast for April 22, Ranger's participants were eager to proceed. Around the nation, Ranger interest was again at a high pitch. In widely quoted testimony before Congress just a few weeks earlier, NASA Administrator James Webb had informed the country that the Soviet Union would continue for the time being to dominate space near the earth with its manned orbiting missions. "But for [manned] landing on the moon and return," he stated, "we are ahead of them." And "if a thousand things go right" with Ranger 4, the New York Sunday News summarily proclaimed, "the U.S. will hit the paschal moon with a spacecraft that will blaze a trail for the first American-and, hopefully, the first earthling-to follow to the moon." 23

On Saturday, April 2, Ranger officials from NASA, JPL, and the Air Force agreed to schedule the first launch attempt for Monday, April 23, having rejected the preceding day, Easter Sunday, out of regard for people’s religious sensibilities. At Cape Canaveral on Monday, clear weather and mild winds made an ideal day on which to undertake or watch a lunar flight. The countdown began in midmorning and proceeded without interruption. Under new arrangements, Ranger Program Chief Cunningham joined Burke in the JFL command post at Hangar AE. The two men remained in constant voice communication with the Air Force personnel conducting launch operations in the blockhouse at Launch Complex 12. With all checks completed, the launch sequence began at 3:50 pm EST, with the familiar puff of white smoke signaling start of the Atlas engines. Ranger 4 rose, on its way to the moon.

Tracking antennas at Cape Canaveral monitored the performance of the Atlas, the Agena, and Ranger until they passed out of sight over the horizon eight minutes after liftoff. By that time the Atlas had staged and separated from the Agena, and Agena first burn had begun. As the Agena coasted into low earth orbit over the South Atlantic, the tracking stations downrange received a steady flow of data. First returns looked good. They confirmed the start of Agena's second burn, and the normality of Ranger's vital signs. The Cape transmitted trajectory data properly to the Johannesburg tracking station in South Africa. As the Agena swung to the southeast and out of view of the antenna on Ascension Island, the picture was very bright indeed.

The mobile tracking antenna promptly located Ranger 4 as it rose over the South African horizon twenty-three minutes after launch. The Agena had completed its second burn; the spacecraft signal, however, indicated immediate, serious difficulties. Though Ranger's transponder was radiating at the 960 megacycle tracking frequency, all telemetry commutation was absent The state of health of the spacecraft could not be ascertained. Two minutes later Ranger 4 separated from the Agena and, as designed, tumbled very slowly on its lunar trajectory. The moment passed when the machine was to extend its solar panels and high-gain antenna and begin stabilizing itself But without telemetry, flight controllers lacked confirmation that these events had taken place. The fluctuating strength of the transponder signal strongly suggested that the spacecraft was still tumbling, its solar panels tucked up firmly against the superstructure and its high gain antenna still stowed over the midcourse engine beneath the spacecraft. The mission was in desperate trouble.

The station at Woomera acquired Ranger's transponder and began tracking the spacecraft as it moved out and away from the earth. These data, relayed to the JPL control center and fed into a computer, permitted an initial trajectory to be calculated. This time the near-perfect performance of the Atlas-Agena B had put Ranger 4 on a collision course with the moon even without a midcourse correction maneuver. But the spacecraft remained inoperative. Burke, who had arrived in Miami aboard an Air Force plane on his way home, approved a series of trouble-shooting commands to be sent from the Johannesburg station in an effort to fathom the spacecrafts true status. Commands to advance the telemetry, to switch the transponder signal from the low-gain antenna to the high gain antenna, to change the high-gain antenna hinge angle, and to override the Spacecraft roll control system were all quickly transmitted. All of them proved futile. At JPL the Spacecraft Data Analysis Team issued a grim prognosis: the master clock in Ranger's central computer and sequencer had stopped. Without that timer, the telemetry decommutator had ceased operating, all timed functions had failed to take place, and the vehicle could not accept and act on commands from earth. For all intents and purposes, Ranger 4 was dead. 24 At the Cape a NASA official lamented: "All we've got is an idiot with a radio signal." 25

The flawless performance of the Atlas-Agena launch vehicle made Burke's own disappointment all the more bitter. Hitting the moon with an idiot Ranger was no consolation. Burke knew there would be "nothing" for science, and little for project engineers. Even the reason for the timer failure could elude detection. Antennas at the downrange stations south of Antigua tracked only the launch vehicle; their receivers were never equipped to monitor the 960-megacycle spacecraft frequency. A six-minute and 17-second gap in coverage of spacecraft telemetry existed between the time Ranger passed out of view of the stations in the Caribbean and the time it was first picked up in South Africa. And the timer had stopped some time during that period. Every single preceding Ranger spacecraft, he recollected, had functioned in space given any opportunity at all-but not Ranger 4.

As Ranger 4 moved inexorably toward its lunar rendezvous, NASA Administrator Webb arrived in Los Angeles for a speaking engagement. Early in the morning of April 26 he flew to the Goldstone tracking station in the Mojave desert, where he joined Nicks, Pickering, Cummings, and Burke. Here, the space officials awaited word of a Luna impact and discussed the Ranger 4 mission with representatives of the press. Electrical power from the spacecraft battery had run out hours before, and Ranger's transponder had ceased to operate. Stations in the Deep Space Network continued their radio tracking nonetheless, homing on the 50-milliwatt signal produced by the tiny battery-powered transmitter in the seismometer capsule. Helping to pass the time the Goldstone station staff supplied their guests with the amplified sound of the seismometer's transmitter and closed circuit television pictures of the moon taken from earth. The transmitter's beep droned off into an inaudible hum ad the spacecraft approached the moon and accelerated under the pull of lunar gravity. The lunar pictures, provided by a camera and telephoto lens aligned through the center of one of one of the large dish antennas trained on Ranger from Goldstone, flickered silently on the monitors. During the final moments the cross-sight was centered on the moon’s leading edge and ,two minutes later, crashed out of sight of the earth on the far side of the moon.

Success had eluded the project once more. Webb told the newsman that the mission still had contributed to the "long strides forward in space" made recently by the United States. And, he added, this spacecraft was far more sophisticated than Lunik 2, which deposited a Soviet pennant on the moon in 1959. Pickering, putting the best face possible on an otherwise dismal outcome, observed that the accuracy of Ranger’s launch vehicle had been fully demonstrated. Ranger 5, he was encouraged to believe, would bring this original phase of the project to a successful conclusion before the end of the year. 26 Later that day, a formal press conference in Los Angeles, James Webb was even less restrained.

Taken in context, he explained, the flight of Ranger 4 had to be considered "an outstanding American achievement." For the first time an American spacecraft had reached the moon. The first American astronaut, Colonel John Glenn, had orbited the earth two months earlier. Just the day before, on April 25, moreover, the second Saturn rocket, the kind that would eventually convey man to the moon, had been launched in a perfect test flight from Cape Canaveral. The nation’s manned lunar program, Webb insisted, remained right on schedule. 27 The press and public seemed to agree. "Ranger 4 Hits Moon, Scores U.S. Space Feat," was a typical lead in the newspaper columns. 28 Though disappointed at the failure of Ranger’s electronic brain, The New York Times said that in this flight "the fact that the moon was reached tells much about the increased power and improved accuracy the United States has achieved in rocket technology." 29 Summing up the week’s events in space, a major West Coast paper concluded: "At last the cheers are drowning out the fears that we are ‘losing’ the space race (Figure 57). 30


Fig. 57. Red, White, and Blue Cross (copyright, Los Angeles Times; Reprinted With Permission)

But Soviet Premier Nikita Khrushchev could not resist the temptation to needle the American Space agency a little. "The Americans," he observed in a press conference of his own, have tried several times to hit the moon with their rockets. They have proclaimed for all the world to heat that they launched rockets to the moon, but they missed every time…" The Soviet pennant already deposited there, he quipped, wad getting lonesome waiting for an American companion. 31 The Soviet Premier’s well-targeted remarks were like salt in an open wound at JPL. Pickering wasted no time reacting. "On April 26, at 4:47.50 am Pacific Standard Time," he declared speaking for the Laboratory as well as for NASA, "Ranger 4 was tracked by the Goldstone receiver as it passed the leading edge of the moon. At 4:49.53 am it crashed on the moon at a lunar longitude of 229.5 degrees East and a lunar latitude of 15.5 degrees South." 32 If the Russians wished to confirm that fact, they could dispatch one of their own astronauts to the spot and investigate it first hand.

But however much space officials or the press praised Ranger at home, there were growing doubts whether the project was living up to American expectations for the space race or, for that matter, even up to expectations held for it by the project engineers and scientists themselves.

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Chapter Nine - Notes

The hyphenated numbers in parentheses at the ends of individual citations are catalog numbers of documents on file in the history archives of the JPL library.

1. Space Programs Summary No. 37-13, Volume I for the period November 1, 1961, to January 1, 1962 (Pasadena, California: Jet Propulsion Laboratory, California Institute of Technology, February 1, 1962), p. 3.

2. John Troan, "US. Plans Three Robot Moon Probes in '62," Washington Daily News, December 27, 196 1, p. 3; also last paragraph of "Masterpiece for the Moon," an editorial in The New York Times, January 19, 1962, p. 30.

3. Cf Marvin Miles, "U.S. Moon Shot May Top Russia’s," Los Angeles Times, January 14, 1962, p. F-1; prior U.S. lunar flight missions are discussed in Chapter One and Appendix B of this volume.

4. William E. Kirhofer, Post-Injection Standard Trajectory, Ranger P-34 (RA3) (JPL Engineering Planning Document 55. Pasadena, California: Jet Propulsion Laboratory, California Institute of Technology, January 5, 1962).

5. Space Programs Summary No. 37-14, Volume 11 (U) for the period January 1, 1962, to March 1, 1962 (Pasadena, California: Jet Propulsion Laboratory, California Institute of Technology, April 1, 1962), P. 5.

6. JPL Interoffice Memo from Albert Hibbs to Experimenters for the Ranger TV Mission, subject: "Dissemination of Ranger-3 Photographs," January 4, 1962 (2-1221b).

7. "Functional Specification Ranger RA-3, RA-4, and RA-5 Spacecraft Mission Objectives and Design Criteria, " in Ranger Spacecraft Design Specification Book, Spec. No. RA345-2-1 10 D (Pasadena, California: Jet Propulsion Laboratory, California Institute of Technology, December 9, 1960) (2-1095e).

8. Nicholas A. Renzetti, Tracking and Data Acquisition for Ranger Missions 1-5 (JPL TM 33-174. Pasadena, California: Jet Propulsion Laboratory, California Institute of Technology, July 1, 1964), p. 3 1.

9. It proved a valuable exercise because less than a month later the same field repair was made on the Mercury-Atlas that carried Lt. Colonel John Glenn into earth orbit aboard Friendship 7.

10. Space Programs Summary No. 37-14, Volume II (U) for the period January 1, 1962 to March 1, 1962 (Pasadena, California: Jet Propulsion Laboratory, California Institute of Technology, April 1962), p. 17.

11. Space Programs Summary No. 37-14, Volume I for the period January 1, 1962, to March 1, 1962 (Pasadena, California: Jet Propulsion Laboratory, California Institute of Technology, April 1, 1962), p. 4; Renzetti, Tracking and Data Acquisition for Ranger Missions 1-5, p. 31.

12. Space Programs Summary No. 37-14, Volume I, p. 44.

13. Ibid., pp. 3-9; Space Programs Summary No. 37-14, Volume II (U), pp. 3-4; Space Programs Summary No. 37-15, Volume VI for the period March 1, 1962, to June 1, 1962 (Pasadena, California: Jet Propulsion Laboratory, California Institute of Technology, June 30, 1962), pp. 7-9; N.A. Renzetti, Tracking and Data Acquisition for Ranger Missions 1-5, pp. 31-38; Ranger 3 Flight Final Statement, January 28, 1962 (2-2500); JPL Ranger 3 Technical Bulletins I through 4, January 29, 1962, through February 9, 1962.

14. Letter from James Burke to Oran Nicks, February 8, 1962 (2-258).

15. JPL Interoffice Memo from James Burke to Brian Sparks, subject: "Ranger Project Status Report No. 44," February 2, 1962 (2-1314); Joseph A. Beacon, Flight Operations Management, Master's Thesis researched at the University of Southern California, January 1969, pp. 38-39 (3-633).

16. Letter from James Arnold to Cargill Hall, August 9, 1973 (2-2391).

17. Gladwin Hill, " Ranger Crosses Path of the Moon; TV Attempt Fails, The New York Times, January 29, 1962, p. 1.

18. "The Disobedient Rocket," Time, February 9, 1962, pp. 67-68.

19. Evert Clark, "Ranger 9 Flight Stirs Reliability Question," Aviation Week and Space Technology, Volume 76, February 5, 1962, p. 30.

20. Quoted by Marvin Miles in "Three Causes Found for Ranger's Failure," Los Angeles Times, February 8, 1962, Part II, p. 2.

21. William E. Kirhofer, Post-Injection Standard Trajectory, Ranger P-35, (RA4) (JPL Engineering Planning Document 56. Pasadena, California: Jet Propulsion Laboratory, California Institute of Technology, April 9, 1962).

22. Space Programs Summary No. 3 7-15, Volume I, pp. 4-8.

23. Tom Allen, " Race for the Moon, " New York Sunday News, April 8, 1962; see also, for example, Dick West, "Lunar Close-ups Expected Soon," Los Angeles Times, April 22, 1962, Part H, p. 5.

24. N.A. Renzetti, Tracking and Data Acquisition for Ranger Missions 1-5, pp. 44-50; Space Programs Summary No. 37-15, Volume 1, p. 3; Space Programs Summary No. 37-15, Volume VAY, pp. 9-10; Space Flight Operations Memorandum Ranger IV (Engineering Planning Document 9 1. Pasadena, California: Jet Propulsion Laboratory, California Institute of Technology, July 5, 1962); James D. Burke, Preliminary Operations Letter Ranger 4 (JPL Reorder 62-144. Pasadena, California: Jet Propulsion Laboratory, California Institute of Technology); JPL Ranger 4 Technical Bulletins I through 3, April 24, 1962, April 25, 1962, and April 26, 1962.

25. Quoted in "Leap Toward the Moon, " Time, May 4, 1962, p. 40.

26. Bill Becker, "Ranger 4 Crashes on the Moon," The New York Times, April 27, 1962, p. 1; Lu Spehr, "Ranger 4 Strikes on Dark Side, " Pasadena Star-News, April 26, 1962, p. 1.

27. "Man on Moon by 1968, Astronaut Chief Declares," Los Angeles Herald-Examiner, April 26, 1962.

28. This headline ran in the Los Angeles Times, April 27, 1962, Part 1, p. 2.

29. "The Ranger Hits the Moon," an editorial in The New York Times, April 27, 1962, p. 34.

30. "A Week of Space Triumph," Los Angeles Times, April 29, 1962, Section C, p. 6.

31. Quoted in "Khrushchev Claims U.S. Missed Moon, but Scientists Refute Him, " Los Angeles Times, May 11, 1962, Part 1, p. 1.

32. Statement by William Pickering confirming Ranger 4 impact on the Moon (2-2412); see also, Astronautical and Aeronautical Events of 1962, Report of the National Aeronautics and Space Administration to the Committee on Science and Astronautics, U. S. House of Representatives, 88th Congress, 1st Session (Washington: Government Printing Office, June 12, 1963), p. 75.

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