This is the second part of a series on the First Race to the Moon. The first part, covering events up to November 1958, is “The First Race to the Moon: Getting Off the Ground”.

As the first full calendar year of the Space Age was winding down, American and Soviet teams were pushing hard to be the first to reach the Moon. Between August and November of 1958, the two countries had made a total of five attempts to launch lunar probes. The two Soviet attempts were unsuccessful due to problems with their newly developed Moon rocket, the 8K72, which was based on the new R-7 ICBM. The first three American probes, originally part of a USAF effort to send spacecraft into lunar orbit but was transferred to NASA in October 1958, at best only made it into ballistic trajectories that brought them nowhere near their target. While these three USAF-sponsored lunar probes were unsuccessful, NASA hoped that the last pair of Pioneer probes developed by teams at JPL (Jet Propulsion Laboratory) under William Pickering and ABMA (Army Ballistic Missile Agency) under Wernher von Braun would fare much better.

The ABMA/JPL Pioneers

The project which would launch the second round of American probes towards the Moon had its origin in a proposal by the JPL and ABMA (parts of which would later become NASA’s Marshall Space Flight Center) to launch a pair of small space probes on escape trajectories using a modified version of ABMA’s Jupiter IRBM during the International Geophysical Year – a cooperative international scientific study of the Earth and its interaction with the Sun running from July 1957 to December 1958. JPL and ABMA were already involved in a number of cooperative space-related programs at this time including one that culminated in the launch of America’s first satellite, Explorer 1, on January 31, 1958 using a highly modified Redstone rocket known as the Juno I launch vehicle (see “Explorer 1: America’s First Satellite”). After the launch of the Soviet Union’s first two Sputnik satellites in the fall of 1957 (see “Sputnik: The Launch of the Space Age” and “Sputnik 2: The First Animal in Orbit”), development of a pair of lunar probes using what would become the Juno II launch vehicle started in November 1957 under the codename “Red Socks”.

For the first stage of the Juno II launch vehicle, Jupiter’s RP-1 and LOX tanks retained their original 2.67 meter diameter but were lengthened by a total of 0.92 meters making the rocket 16.84 meters long. This prolonged the burn time of the 668 kilonewton thrust Rocketdyne S3D engine by 20 seconds to a total of 182 seconds. Mounted on top of the modified Jupiter first stage under an aerodynamic shroud was the “high speed assembly” consisting of an instrument compartment and a three-stage solid rocket cluster developed by JPL and similar to that used on ABMA’s Juno I rocket. This cluster of rocket motors was a spin-stabilized tub of 11 scaled-down JPL Sergeant rockets with seven used for the second stage, three for the third and a single motor for the fourth stage. Modifications of this cluster from the version used on the Juno I and earlier Jupiter-C used for high speed reentry tests included filling the third and fourth stages with a higher performance propellant and changing the original stainless steel casing of the fourth stage to a lighter weight titanium casing. The Juno II was designed to place 43 kilograms of payload in a 480-kilometer high Earth orbit or up to 7 kilograms of useful payload on a direct ascent escape trajectory.

On March 27, 1958 President Eisenhower approved a plan for the Defense Department’s new Advance Research Projects Agency (ARPA) to launch a series of five missions to the Moon over the following year as part of “Operation Mona” with the hope of beating the Soviet Union to the Moon. The first missions were a USAF proposal to use their Thor-Able rocket, which had been originally developed for high speed reentry tests, to launch three probes with the ambitious goal of orbiting the Moon. Following these missions, the more modest ABMA-JPL lunar probes would be launched on lunar flyby missions.

On May 2, 1958 ABMA officially contracted JPL to develop and build four of the tiny lunar probes of which two would be launched on missions designated “Juno IIA” and “Juno IIA-Prime”. With a mass of just 6.67 kilograms each (which would qualify them as “nanosatellites” by today’s definition), the probes were a 23-centimeter wide cone with an 8-centimeter spike antenna on the top. They were 51 centimeters long with an exterior housing constructed of gold-washed fiberglass. The exterior was gold plated and striped with paint for passive thermal control. The electrically conductive gold plating on the cone also served as an unsymmetrical dipole antenna element in conjunction with the spike antenna. At the squat cylindrical base of the probe was a despin mechanism consisting of two 1.5-meter long weighted wires. A hydraulic timer would release the wires ten hours after launch. As the wires unwound, the payload’s spin rate would decrease from 400 to 11 revolutions per minute. Located inside the probe was a 500-gram UHF transmitter operating at a frequency of 960 MHz with an effective power of 180 milliwatts. The power supply for the transmitter and instruments consisted of a set of eighteen mercury cells.

Tracking of the probes would be performed using a facility employing a 3-meter antenna in Mayaguez, Puerto Rico during the early phases of the mission. As the probe receded farther from the Earth, a 26-meter antenna at the new Deep Space Instrumentation Facility known as the “Goldstone Station” at Camp Irwin in California’s Mojave Desert would be used. This latter facility would become the basis of the Deep Space Tracking Network that would communicate with NASA’s lunar and planetary spacecraft for decades to come. The probe’s coordinates, Doppler velocity and telemetry data would be channeled directly from these tracking stations to JPL in Pasadena, California for reduction and analysis.

Originally these JPL-built lunar probes were to carry a tiny 35 mm photographic package capable of obtaining a single photograph of the Moon’s far side during a lunar flyby. A photoelectric triggering device would trip the camera’s shutter when the Moon was in the detector’s field of view and closer than 32,000 kilometers. The photograph would then be developed and scanned. By September of 1958, the design of this system had been finalized and parts of it were under development testing. But with the discovery of the Van Allen radiation belts surrounding the Earth by the first Explorer satellites during 1958, the JPL Moon probes’ primary instrument was changed to a pair of Geiger-Mueller tubes to obtain data on the radiation environment between the Earth and Moon. The original photoelectric triggering device along with the despin mechanism (needed to slow the probe’s rotation in order to allow photography) were retained as engineering tests for future systems.

With the new instrument, the mission of this probe was also changed. Instead of a close flyby, the probe was now intended to impact the lunar surface 33 hours and 45 minutes after launch when the Moon was best positioned to be seen by the Goldstone tracking station. But given the inherent inaccuracy of direct ascent trajectories, the relatively crude nature of the Juno II solid rockets and the guidance system, as well as the lack of any course correction capability, the JPL-ABMA probes would be lucky to make it anywhere near the Moon never mind hit it. Nonetheless, at this early stage of space exploration a lunar flyby was just as valuable scientifically as a direct hit. September of 1958 was initially set as the tentative launch date for their first ABMA-JPL Moon shot. With luck the ARPA-sponsored Moon probes, in addition to providing valuable IGY data, would get America ahead of the Soviet Union in the Space Race.

The December 1958 Launches

With this last Pioneer orbiter flight launched in November, NASA’s lunar hopes turned to the pair of smaller ABMA-developed Pioneer flyby probes which would be ready to launch in December. Trajectory requirements to reach the Moon while the probe was in view of the Goldstone station dictated a 50-minute launch window on December 6 followed by daily 80-minute windows on December 7 through 12. But the different trajectory requirements of this probe dictated a launch window that opened two days after the next Soviet E-1 launch attempt on what was then the world’s largest rocket, the 8K72 (see “The Largest Launch Vehicles Through History“). Fortunately, the Soviet commission charged with finding the reason for the first two 8K72 launch failures were able to trace the source of the problem. While the longitudinal vibrations during powered ascent called “pogo” had been largely eliminated from the two-stage R-7 variants, it was discovered that the addition of the new Blok E third stage raised the rocket’s center of gravity in such a way to make the problem reappear. A simple baffle was introduced in the boosters’ oxidizer pipeline to eliminate the effect and Korolev’s team was ready to try for the Moon again.

Despite the growing pains experienced during the first 8K72 launches and lagging development of its larger sister Moon rocket, the 8K73, Chief Designer Sergei Korolev’s team of engineers at OKB-1 (Experimental Design Bureau 1 – the forerunner of today’s RKK Energia) were quickly climbing the learning curve enabling them to build more reliable and higher performance machines based on the adaptable R-7 ICBM. One such change was to load the Blok E third stage of the 8K72 with a denser grade of kerosene than RG-1 grade used by the core and boosters thus increasing the stage’s fuel mass. These and other refinements now allowed the 8K72 to loft over 360 kilograms into a direct ascent, 34-hour long trajectory towards a lunar impact. Over the coming months these enhancements would doom the increasingly redundant and troubled 8K73 development program.

Originally limited to an estimated mass of 170 kilograms, the E-1 probe nicknamed “Lunik” by its builders at OKB-1 (a moniker that was later applied by the West to all early Soviet lunar probes) could now afford to gain some weight. The E-1 was a 1.2 meter in diameter, polished aluminum-alloy sphere with a pressurized interior designed to maintain a temperature of 20° C. It contained all the sensitive electronic equipment including the transmitter, instruments, and batteries to power it all. Data would be transmitted at preprogrammed intervals in order to extend the battery life to about 60 hours.

Its suite of scientific instruments included a magnetometer mounted on a meter-long boom, a piezoelectric micrometeorite detector and devices to detect and characterize various types of cosmic radiation including versions of an instrument which had been flown earlier in Earth orbit on Sputnik 3 launched in May of 1958 (see “Sputnik 3: The First Orbiting Geophysical Laboratory”). The E-1 also carried a pair of spheres, one 15 and the other 9 centimeters in diameter, composed of small medallions bearing the coat of arms of the Soviet Union. The spheres were designed to shatter on impact spreading the medallions across the impact site to commemorate the historical achievement. The fattened E-1 weighed in at about 192 kilograms.

Instead of wasting the unused payload capability of the 8K72, it was decided that the Blok E escape stage would carry another 169 kilograms of scientific and radio-equipment to supplement Lunik’s measurements. Included was a package to vaporize one kilogram of sodium to produce a short-lived artificial comet on the way to the Moon. Originally suggested by Soviet astronomer Iosef Shklovsky, this experiment would yield interesting insights into Earth’s outer magnetosphere and serve as a tracking aid.

The next 8K72, serial number B1-5, lifted off carrying E-1 No. 3 at 21:18:44 Moscow Time (18:18:44 GMT) on December 4, 1958 from Area 1 of NIIP-5 test range (Scientific Research Test Range No. 5 – today known as the Baikonur Cosmodrome) near the town of Tyuratum in Soviet Kazakhstan. Unlike the first two flights, this time the rocket flew flawlessly through to the dropping of its four boosters. The pogo problem had finally been solved. But 245 seconds after launch as the core was still firing, thrust in its RD-108 engine dropped to 70% and then quit altogether. A failure in the engine’s turbopump had brought the Soviet’s third attempt to reach the Moon to a premature end.

While rumors of this and other launch failures circulated for years, details would remain secret until the fall of the Soviet Union 34 years later. In the meantime, engineers at OKB-1 would have to prepare another E-1 probe and 8K72 launch vehicle for a fourth attempt near the New Year. But before then, NASA’s next Pioneer probe would get its chance to reach the Moon first.

Meanwhile back in the US, preparations were proceeding for the launch of the first of the ABMA-JPL lunar probes designated the Juno IIA mission. With the Jupiter Round AM-11 already on its launch pedestal at Launch Complex 5 (LC-5) at Cape Canaveral, the high-speed assembly was added to the stack at 8:00 AM EST on December 1. With the final pre-launch testing completed, the countdown was started at T-9 hours at 12:40 PM EST on December 5. Including 185 minutes of built in hold time in the countdown, launch was expected at just before 12:45 AM EST.

The Juno IIA mission lifted off from LC-5 at 12:44:52.3 AM EST (05:44:52.3 GMT) on December 6, 1958 – just four seconds after the optimum launch time in its 50-minute launch window. While at first the launch of what was designated Pioneer 3 looked good, a review of the telemetry showed that the Jupiter booster had cut-off 3.7 seconds too early due to a failure in the propellant tank depletion sensors resulting in a 382 meter per second velocity shortfall at the ignition of the high speed assembly. Minor dispersions during the burns of the upper three stages resulted in a trajectory with Pioneer 3 travelling 1.1° lower and 4.6° farther south than planned. As a result, Pioneer 3 had failed to reach escape velocity just like its USAF predecessors. Telemetry from Pioneer 3 also indicated that its despin mechanism failed to operate at 15:30:00 GMT as intended leaving the probe spinning at the rate of 415 rpm instead of the slower 11 rpm.

Pioneer 3 reached a peak altitude of only 102,300 kilometers before it arced back to Earth and burned up over what was then French Equatorial Africa 38 hours and 6 minutes after launch. Despite the failure, Pioneer 3 still made useful measurements that confirmed the extent of Earth’s Van Allen radiation belt and discovered a second belt between 16,000 and 64,000 kilometers above the Earth. While scientifically important, it still did not make up for the fact that yet another American spacecraft failed to reach the Moon.

With the failure of Pioneer 3 to reach the Moon, two additional probes – serial numbers 3 and 4 which were flight spares from the original Juno IIA mission – were modified and prepared so that one could be launched on the Juno IIA-Prime mission.

Success… Sort of

As the end of December approached, Korolev and his team pushed hard to make their next launch attempt to the Moon on New Year’s Day 1959. Preparations proved difficult as the temperatures on the snow-covered steppes of Soviet Kazakhstan dropped to -30° C and the launch crews were pushed almost to exhaustion. As the world rang in 1959, 8K72 serial number B1-5 was finally rolled out onto its pad at Area 1 at the NIIP-5 test range. Under the rocket’s nose was 361.3 kilograms of payload including the E-1 No. 4 Lunik probe. At 19:41:21 Moscow Time (16:41:21 GMT) on January 2, the giant 8K72 Moon rocket lifted off in the Soviets’ fourth attempt to reach the Moon. Unlike the previous flights, this time the first two stages did not suffer any major malfunctions allowing the Blok E stage to push its cargo towards the Moon.

Initial tracking of the probe and its escape stage indicated that everything worked and that escape velocity had been achieved for the first time leading to the Soviet designation of “the First Cosmic Ship”. Lunik, now officially named “Mechta” (Russian for “Dream” but, starting in 1963, this mission was retroactively designated “Luna 1”), was on its way to the Moon. Eight hours after launch at an altitude of about 120,000 kilometers over the Indian Ocean, the spent Blok E released a fluorescent cloud of sodium vapor that expanded to 650 kilometers across in five minutes before disappearing from sight. Visible from most of the Eastern Hemisphere, this spectacle was proof that the Soviets were on the way to the Moon.

Despite the initial flurry of excitement, careful tracking indicated that the Blok E escape stage had been misprogrammed imparting slightly too much speed causing the probe to miss the Moon. On January 4 some 34 hours after launch, Luna 1 passed within 6,000 kilometers of the Moon. Even though it failed to hit the Moon as intended, the probe’s instruments worked perfectly and returned useful data on the cis-lunar environment for the first time. The Soviet press, however, trumpeted the flight as a total success with the first close pass by the Moon.

Luna 1 was tracked until 62 hours after its launch on January 5, 1959. At a range of about 597,000 kilometers, the probe’s batteries finally gave out ending a less than successful but very fruitful mission. The now silent First Cosmic Ship continued on in a 0.978 by 1.318 AU (146.4 by 197.2 million kilometer) solar orbit with a period of 449.5 days to become the first “manmade planet” to orbit the Sun (although aluminum pellets launched from an American Aerobee sounding rocket in October 1957 might be claimed as being the first objects launched into solar orbit – see “Fritz Zwicky’s Solar Orbiting Pellets”). The partial success of Luna’s mission provided enough fuel for the Soviet propaganda machine to allow Korolev the time he needed to analyze the mission’s results and plan the next step. In the meantime, another apparent space first for the Soviet Union along with the immense size of the payload weighed heavily on an increasingly nervous West.

America’s Reply

The success of the Soviet Luna probe had an incredible impact on NASA. Under increasing pressure, the Juno IIA-Prime mission just had to succeed. Modifications were made by von Braun’s ABMA team to Jupiter Round AM-14 to be used on this flight to prevent a recurrence of the propellant depletion sensor issue experienced during the Pioneer 3 launch. The high speed assembly for this launch was essentially identical to its predecessor and included extra instrumentation to study the trajectory dispersion issue. Except for some additional lead shielding on one of the Geiger-Muller tubes and other modifications to improve the performance of the telemetry system, the 6.08-kilogram probe for the Juno IIA-Prime mission was identical to Pioneer 3.

The high speed assembly for the Juno IIA-Prime mission arrived at Cape Canaveral on January 21, 1959. Modifications and testing of the upper stages were completed on February 18 and were subsequently stacked atop of its Jupiter booster at LC-5 for further prelaunch testing. The primary payload, serial number 3, arrived at Cape Canaveral on February 9 with the backup payload, serial number 4, arriving three days later. Because of issues uncovered with the communications system on No. 3, No. 4 was selected on February 26 as the payload to be launched for this mission. There were daily launch windows available for the Juno IIA-Prime mission running from February 28 to March 4.

The first launch opportunity started at 9:00 PM EST on February 28, 1959 but the attempt was cancelled because of predictions of a low ceiling and low visibility which would violate a Cape-wide range safety requirement of a ceiling above 60 meters and minimum visibility of 6.4 kilometers for any launch. Preparations for payload no. 4 were completed on March 1 and it was mounted on the top of the final stage of the Juno II at about 2:00 PM EST. The countdown proceeded to the T-20 minute mark when problems were encountered trying to switch the payload to internal power prior to liftoff. With the problem being investigated, the countdown was recycled at the T-5 minute mark to T-30 minutes for a second launch attempt. When the problem was found to be with the payload, the launch was scrubbed and the fourth stage with the probe attached were removed from the launch vehicle. It was discovered that the attempt to power up payload No. 4 had damaged some internal components forcing engineers to substitute No. 3 despite the unexplained minor shift in frequency in its communications system.

The countdown for the next launch attempt started at 12:06 PM EST on March 2, 1959. The countdown proceeded without any major problems until a hold at the T-2 minute mark to adjust the count for a 12:10:50 AM EST launch. At 12:10:56.7 AM EST (05:10:56.7 GMT) on March 3, Pioneer 4 finally lifted off the pad at LC-5 with the slight delay caused by the unexpectedly slow action of a couple of propellant valves in the Jupiter. At 276.6 seconds after launch, telemetry showed that Pioneer 4 had separated from its fourth stage following the successful firing of all stages.

A slightly longer than planned burn of the second stage along with a nearly nominal performance of the other stages guaranteed this time that the 11,079 meter-per-second velocity of Pioneer 4 had surpassed escape velocity 80 meters per second. But calculations based on early tracking of the receding probe quickly showed that this excess velocity and the inevitable aiming errors (amounting to 4.5° too low in elevation angle and 1.3° too far south) conspired to place Pioneer 4 on a trajectory that would not pass within 32,000 kilometers of the Moon (or hopefully impact it!) as planned. Instead it would pass ahead of and below the Moon at a distance of 60,000 kilometers or around 35 lunar radii – a wide miss by any measure.

At about 22:11 GMT on March 4, 41½ hours after launch, Pioneer 4 passed the Moon and continued to relay its measurements back to the 26-meter tracking antenna at the Goldstone Station. After 82 hours of operation, the probe’s batteries were finally exhausted at 15:40 GMT on March 6 as Pioneer 4 passed a range of 655,000 kilometers on its way into solar orbit – a new long distance communications record at the time. Engineers were confident that they could have tracked Pioneer 4 out to a range of 1.1 million kilometers if the batteries had not given out. Pioneer 4 entered a 0.98 by 1.13 AU (147 by 169 million kilometer) orbit with a period of 398 days where it remains today. Although it was quite small and failed to beat the Soviet Union to the Moon, Pioneer 4 was a much needed success. Unfortunately, it would be another 5½ years before the next NASA lunar mission succeeded with the flight of Ranger 7 (see “The Mission of Ranger 7”).

The First Lunar Impact

Even though the flight of Luna 1 had generated a lot of propaganda, the goal of actually hitting the Moon was still unachieved. After a five-month hiatus to study the results of the Luna 1 mission, Korolev and his team were ready to try again. The next probe would be a modified version of the original probe designated E-1A with improvements made to the instruments and the antenna housing.

The first of these improved probes, E-1A No. 5, was set to be launched on 8K72 serial number I1-7 on June 16, 1959. Because the fuel tanks of the Blok E escape stage were mistakenly filled with a lighter grade of kerosene than specified, the launch was postponed while the tanks were emptied and flushed. At 11:08:00 Moscow Time (08:08:00 GMT) on June 18, the Soviet Union’s fifth attempt to impact the Moon lifted off from NIIP-5. But unlike the previous launch, this ascent would not pass without incident. About 153 seconds into the mission, the gyrohorizon in the rocket’s guidance system failed. Unable to sense its attitude, the uncontrolled rocket and its payload were destroyed by range safety.

After a short review to determine the cause of the failure and correct it, 8K72 serial number I1-7A was rolled out onto the pad for an attempt to launch 390.2 kilograms of payload including the E-1A No. 6 probe on September 9, 1959. This attempt was timed to take place just before Khrushchev’s tour of the United States which was set to start on September 15. A successful mission would give the Soviet Premier a valuable propaganda tool. But the first attempt was aborted a half a second before liftoff when the core’s engine failed to attain full thrust. The rocket was removed from the pad and its payload was quickly transferred to a backup launch vehicle. At 09:39:42 Moscow Time (06:39:42 GMT) on September 12, 8K72 serial number I1-7B successfully lifted off and finally sent a second Soviet probe towards the Moon.

Radio tracking and sightings of the sodium vapor cloud released by the escape stage six hours after launch at a distance of 156,000 kilometers confirmed that the “Second Cosmic Rocket” had not only escaped the Earth but was on course for a lunar impact. At 21:02:23 GMT on September 13, 1959 what would later become known as Luna 2 impacted the Moon at about 30° north latitude on the lunar prime meridian near the crater Archimedes at a speed of 3.3 kilometers per second. The silent Blok E escape stage followed 30 minutes later. Data returned by Luna’s instruments found no evidence of the Moon having a magnetic field or radiation belts like the Earth. While observations by Eastern Bloc astronomers of a dust cloud kicked up by the impact were unconfirmed by their counterparts in the West, the radio dish at Jodrell Bank tracked the Luna 2 as it accelerated towards the surface independently confirming the historical feat. The Soviet Union had another space first.

The importance of this near-bullseye shot was not lost on leaders in the West. Not only were the Soviet Union the first to hit the Moon, they obviously had the technology needed to hit any target near (and presumably on) the Earth. But with this new milestone attained, Korolev quickly turned to beat the Americans again to the next goal: Securing the first images of the unseen far side of the Moon.

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Related Videos

This is a short NASA documentary about the Pioneer 4 mission.

Here is a Universal Newsreel about the Luna 2 mission:

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Related Reading

“The First Race to the Moon: Getting Off the Ground”, Drew Ex Machina, November 8, 2018 [Post]

General References

M. Eimer, A.R. Hibbs and R. Stevens, “Tracking the Moon Probes”, in Space Research: Proceedings of the First International Space Science Symposium, edited by Hilde Kallmann Bijl, Interscience Publishers, pp. 518-531, 1960

Brian Harvey, Soviet and Russian Lunar Exploration, Springer-Praxis, 2007

Wesley T. Huntress and Mikhail Ya. Marov, Soviet Robots in the Solar System: Mission Technologies and Discoveries, Springer-Praxis, 2011

Nicholas Johnson, Handbook of Soviet Lunar and Planetary Exploration, Univelt, 1979

Conrad S. Josias, “Radiation Instrumentation Electronics for the Pioneers III and IV Space Probes”, Proceedings of the IRE, Vol. 48, No. 4, pp. 735-743, April 1960

William H. Pickering, “History of the Juno Cluster System”, in Astronautical Engineering and Science, edited by Ernst Stuhlinger, Frederick I. Ordway III, Jerry C. McCall, and George C. Bucher, McGraw-Hill Book Co., pp. 203-214, 1963

Asif Siddiqi, “First to the Moon”, Journal of the British Interplanetary Society, Vol. 51, No. 6, pp. 231-238, June 1998

Timothy Varfolomeyev, “Soviet Rocketry that Conquered Space Part 2: Space Rockets for Lunar Probes”, Spaceflight, Vol. 38, No. 2, pp. 49-52, February 1996

Timothy Varfolomeyev, “Soviet Rocketry that Conquered Space Part 3: Lunar Launchings for Impact and Photography”, Spaceflight, Vol. 38, No. 6, pp. 206-208, June 1996

Allen E. Wolfe, “Juno Final Report Volume II Juno II: Space Probes”, JPL Technical Report No. 32-31, September 12, 1961

The Moon Probe Pioneer IV, NASA-JPL, c1959