Luna 9 Makes the First Successful Lunar Soft Landing Summary

  • Last updated on November 10, 2022

The Soviet spacecraft Luna 9 became the first human-made object to soft-land on another celestial body. Luna also returned photographs from the Moon’s surface.

Summary of Event

The Soviet lunar landing attempts were initiated in January, 1963, with the unsuccessful launching of a lunar soft-landing spacecraft. Six more failures would follow over the next three years before Luna 9 made the first successful soft landing on another planet. The chief designers were G. N. Babakin, Valentin Glushko, A. M. Isayev, Sergei Korolev, and Mikhail Ryazanski. The principal investigator was A. I. Lebedinsky. Luna program Space program, Soviet;Luna program Lunar landings [kw]Luna 9 Makes the First Successful Lunar Soft Landing (Jan. 31-Feb. 6, 1966) [kw]Soft Landing, Luna 9 Makes the First Successful Lunar (Jan. 31-Feb. 6, 1966) Luna program Space program, Soviet;Luna program Lunar landings [g]Europe;Jan. 31-Feb. 6, 1966: Luna 9 Makes the First Successful Lunar Soft Landing[08810] [g]Soviet Union;Jan. 31-Feb. 6, 1966: Luna 9 Makes the First Successful Lunar Soft Landing[08810] [c]Space and aviation;Jan. 31-Feb. 6, 1966: Luna 9 Makes the First Successful Lunar Soft Landing[08810] [c]Astronomy;Jan. 31-Feb. 6, 1966: Luna 9 Makes the First Successful Lunar Soft Landing[08810] [c]Science and technology;Jan. 31-Feb. 6, 1966: Luna 9 Makes the First Successful Lunar Soft Landing[08810] Babakin, G. N. Glushko, Valentin Isayev, A. M. Korolev, Sergei Lebedinsky, A. I. Ryazanski, Mikhail

Luna 9 was launched at 11:42, Greenwich mean time(GMT) on January 31, 1966, by a three-stage A-2e booster from the Baikonur Cosmodrome at Tyuratam (now in Kazakhstan). The 43-meter-tall, 509,840-kilogram thrust booster placed Luna 9 into a temporary 169-by-219-kilometer Earth parking orbit. Before completing its first orbit, the third stage reignited and propelled Luna 9 into a translunar trajectory. Because Luna 9 would not enter Earth’s shadow during the long cruise to the Moon, the spacecraft was slowly rolled at a rate of 4 degrees per second to distribute evenly the heat from the direct solar radiation.

The 1,583-kilogram, 2.7-meter-long Luna 9 spacecraft consisted of three basic sections. The upper portion was a 58-centimeter-diameter, 100-kilogram spherical landing capsule carrying a television camera and radiation detector. Below this was a 1-meter-diameter cylindrical compartment containing the control and communications equipment. The bottom portion of the spacecraft housed a 45.5-kilonewton-thrust KTDU-5A mid-course correction and retro-rocket engine. Fuel, weighing 800 kilograms, was stored in a 90-centimeter spherical nitric acid tank and a doughnut-shaped aluminum hydrazine tank above the engine.

The spacecraft’s initial trajectory would have resulted in a 9,600-kilometer miss of the Moon. On February 1, while still 233,000 kilometers from its target, Luna 9 performed a course correction with a 71.2-meter-per-second velocity change to ensure a lunar impact.

The Soviet technique for landing a spacecraft on the Moon involved aiming at the western edge of the Moon. This was done so the motion of the Moon’s orbit would intercept the descending spacecraft along a line with the local lunar vertical. This simple technique limited Soviet landers to an area near 64 degrees west along the lunar equator and eliminated the need for canceling horizontal velocity as well.

On February 3, while the spacecraft was still 8,300 kilometers from the Moon, Luna 9 assumed a vertical attitude in relation to the Moon in preparation for landing an hour later. At this point, lunar gravity was accelerating the spacecraft toward the Moon at a speed increasing by 1.3 meters per second each second. After seventy-nine hours of flight and at an attitude of 75 kilometers, a radar altimeter operating at 93 megahertz triggered the ignition of the retro-rocket for a forty-six-second burn. Simultaneously, 300 kilograms of equipment no longer needed was jettisoned to lighten the spacecraft. The retro-rocket slowed the spacecraft from a 2.6-kilometer-per-second descent speed to about 25 meters per second just above the surface. The Pulkovo Observatory in Leningrad filmed the high-speed impact of the discarded Luna 9 equipment as it struck the Moon’s surface. As the spacecraft approached the Moon over Oceanus Procellarum Oceanus Procellarum , a proximity sensor mounted on an extended arm detected the lunar surface. This signaled shutdown of the rocket motor and ejected the shock resistant landing capsule off to one side, away from the area swept by the rocket blast. The capsule was weighted on one side to roll into an upright position.

Luna 9’s spherical landing capsule.

(NASA)

Landing occurred at 18:45:30 GMT on February 3. Touchdown occurred in the western area of the Moon known as the Ocean of Storms. The craft landed halfway up the inner slope of a small 25-meter-diameter crater near the large crater Reiner shortly after local sunrise. Immediately after landing, the upper half of the lander’s shell split open into four spring-loaded petals that stabilized the capsule in an upright position. Four minutes and ten seconds after landing, four 75-centimeter antenna rods and an 8-centimeter-diameter television apparatus turret popped up from the lander, and radio contact was established.

The lander’s television, a simple 1.5-kilogram facsimile system requiring only 2.5 watts of power, quickly began to scan the surrounding lunar details. Panoramic photographs of the local terrain were taken from a height of 60 centimeters and showed the horizon about 1.5 kilometers away. The camera system was designed to be tilted 16 degrees. This tilt allowed the panoramic view to vary from 11 degrees above to 18 degrees below the horizon and allowed close-ups of near objects as well as views toward the horizon. The rotating camera turret used a nodding mirror to scan 360 degrees and took one hundred minutes to complete a panorama. Each panorama was made of eight exposures, each having a resolution of four lines per millimeter on a picture 2.5 centimeters by 2.75 centimeters. The system had a sharpness about twice that of commercial broadcast television, achieving a resolution one-third that of the human eye. This allowed nearby objects as small as 2 millimeters to be imaged.

The first historic panoramic photograph from the lunar surface was transmitted by Luna 9 to Earth between 01:50, and 03:37 GMT on February 4. A second panorama was transmitted ten hours later, between 14:00, and 16:54 GMT. A third panorama was sent the next day between 20:37, and 22:55 GMT on February 5. The elevation of the Sun changed from seven to thirteen degrees, then to twenty-seven degrees between the three exposures. This changed the shadow relief between each panorama, allowing further study of lunar surface details. Between the first and second panoramas, the landing capsule shifted slightly as it settled into the lunar soil. This settling changed the tilt of the imaging system from 16.5 to 22.5 degrees and moved the camera’s perspective approximately the distance between two human eyes. This fortuitous accident then allowed stereoscopic study of nearby objects.

Luna 9’s periods of activity were limited to when the Moon was in line of sight with the Soviet Deep Space Communication Center’s antenna at Yevpatoria, in the Crimea. To conserve the lander’s batteries, the craft was shut down when it was not in range of the tracking station. When Luna 9 was active on the surface, live signals from the lander were played over Moscow radio and television. The signals sounded like the slow ticking of a grandfather clock through the hiss of radio static.

On February 6, the Soviets announced that contact with Luna 9 had concluded after a total of eight hours and five minutes of communication with the craft over three days. Nevertheless, two days later, Luna 9 surprised Western observers by transmitting three more poor-quality photographs. Higher than expected battery reserves had allowed the Soviets to exercise the lander one more time before power depletion.

The historic first soft landing on the Moon by Luna 9 was the first direct evidence that piloted lunar exploration was possible. Luna 9 showed that the feared, deep layers of soft, unstable, spacecraft-swallowing dust predicted by astronomer Thomas Gold did not exist and that the Moon’s surface was capable of supporting a spacecraft.

Significance

The importance of the first soft landing by a spacecraft on another planet must be examined not only from a scientific standpoint but also for its place in political history. In the 1960’s, the Soviet Union and the United States were in a scientific as well as a political Cold War. The race between the two nations to reach the Moon first was very much a matter of national pride and prestige for the United States and a continuous source of pro-Communist propaganda for the Soviets.

Any mention of Soviet attempts to reach the Moon in the 1960’s brings images of Soviet premier Nikita S. Khrushchev Khrushchev, Nikita S. [p]Khrushchev, Nikita S.;space program gloating about the success of his space spectaculars while the early American space efforts floundered. Khrushchev professed a theme that equated Soviet success in space with socialist superiority on Earth. Although Khrushchev had been removed from power sixteen months before the Luna 9 landing, his space legacy was still a driving force in the competition between the United States and the Soviet Union to reach the Moon first. Indeed, when Luna 9 made its historic landing, Soviet newspapers featured the headline, “The Moon Speaks Russian.”

Scientifically, Luna 9’s single most important discovery was that the lunar surface was strong enough to support a spacecraft. The successful lunar landing ended a decade-long debate between leading lunar experts about whether the Moon’s surface was covered with a fine layer of fluffy dust many meters deep, which would swallow any craft trying to land on it. The fact that Luna 9 rested firmly on a solid lunar surface was welcome news to planners in the U.S. Apollo piloted Moon landing project. The Luna 9 data contributed to the American decision to abandon experimental designs for a six-legged lander and concentrate on the lighter, four-legged design eventually used.

The historic first photographs from the surface of another planet became embroiled in international intrigue. The Soviets did not release the lunar photographs immediately. During the Soviet delay, scientists at the Jodrell Bank radio telescope in England intercepted the signals from Luna 9. Technicians discovered that when the Luna’s signals were fed into a standard news wire service photograph facsimile machine, pictures of the lunar surface were produced. Not knowing the true scale of the lunar views as transmitted by Luna 9’s photographic apparatus, the English versions of the lunar photographs were distorted vertically by a factor of 2.5. This had the effect of making all lunar features appear sharper and more jagged than they really were. This distortion misled some experts into declaring that snowshoelike devices would be needed to walk on the Moon and American equipment would have to be modified prior to a piloted landing.

The Soviets were incensed by what they called the English piracy of their Luna 9 photographs. While the unauthorized release of the distorted Luna photographs by the English annoyed the Soviets, however, it gave worldwide credibility to the Soviet achievement at a time when many doubted that the Soviets had really succeeded in landing on the Moon. After several days, properly scaled Soviet versions of the Luna 9 panoramas were released by Moscow. These views showed the lunar surface to be a rough-textured surface, covered with rocks and boulders of various sizes, but smooth enough to be easily traversed by a visiting astronaut.

Luna 9’s only other instrument—an SBM-10 radiation detector—showed the average radiation dosage on the lunar surface was 30 millirads per day, a dose safe for human exploration of the Moon. It was deduced further that this radiation was primarily cosmic rays, while some of it was radiation from lunar material induced by cosmic rays. Luna program Space program, Soviet;Luna program Lunar landings

Further Reading
  • citation-type="booksimple"

    xlink:type="simple">Gatland, Kenneth. Robot Explorers. London: Macmillan, 1972. A chronology of Soviet and American lunar and planetary space exploration programs. Contains numerous color illustrations providing insights into the design and functions of American and Soviet lunar and planetary spacecraft. Descriptive narrative provides details and results of all Soviet and American lunar and planetary exploration spacecraft and their missions. Suitable for general readers.
  • citation-type="booksimple"

    xlink:type="simple">Hartmann, William K. Moons and Planets. 5th ed. Belmont, Calif.: Brooks/Cole, 2005. Provides detailed information about all objects in the solar system. Suitable on three separate levels: high school students, general readers, and college undergraduates studying planetary geology.
  • citation-type="booksimple"

    xlink:type="simple">McDougall, Walter A. The Heavens and the Earth: A Political History of the Space Age. 2d ed. Baltimore: Johns Hopkins University Press, 1997. A political history of the space age. A well-researched and heavily footnoted historical text that describes and analyzes the decisions by the leaders of both the United States and the Soviet Union and their effects on their respective space programs.
  • citation-type="booksimple"

    xlink:type="simple">Scott, David, and Alexei Leonov. Two Sides of the Moon: Our Story of the Cold War Space Race. New York: Simon & Schuster, 2004. A personal account of the space race between the Soviet Union and the United States by two major players in the programs of their respective countries.
  • citation-type="booksimple"

    xlink:type="simple">Short, Nicholas M. Planetary Geology. Englewood Cliffs, N.J.: Prentice Hall, 1975. Summarizes the accomplishments and scientific results of both American and Soviet lunar and planetary space programs. Stresses the chemical nature of the Moon and inner planets, their geological similarities and differences, and their origins. College-level reading, illustrated with many diagrams and photographs.
  • citation-type="booksimple"

    xlink:type="simple">Smolders, Peter L. Soviets in Space: The Story of the Salyut and the Soviet Approach to Present and Future Space Travel. Translated by Marian Powell. New York: Taplinger, 1974. A well-illustrated narrative on all aspects of the Soviet space program. Suitable for general readers; concentrates on the successful portions of the Soviet space program as they were reported by the Soviet Union. Contains numerous diagrams and photographs illustrating the technical details of Soviet spacecraft and their missions.
  • citation-type="booksimple"

    xlink:type="simple">Stoiko, Michael. Soviet Rocketry. New York: Holt, Rinehart and Winston, 1970. An overview of the Soviet space program, tracing the evolution of Soviet rocket development and satellite technology. Speculates on future Soviet space activities. Nontechnical narrative suitable for general readers.
  • citation-type="booksimple"

    xlink:type="simple">Turnill, Reginald. The Observer’s Spaceflight Directory. London: Frederick Warne, 1978. A lavishly illustrated summary of spaceflight activities by all nations. Lists chronologies of major piloted and unpiloted space missions. Technical narrative describes worldwide space activities by nation and program, providing details of spacecraft, mission summaries, and program results. Suitable for readers at the high school and college level.
  • citation-type="booksimple"

    xlink:type="simple">U.S. Congress. Senate Committee on Commerce, Science, and Transportation. Manned Space Programs and Space Life Sciences. Part 2 in Soviet Space Programs, 1976-80. Washington, D.C.: General Printing Office, 1984. Comprehensive descriptions of all phases of unpiloted Soviet space programs. Provides a detailed overview of the technical development of Soviet unpiloted space activities, scientific investigations and results, and the political effects of Soviet space activities. The standard general reference for data on Soviet space programs.
  • citation-type="booksimple"

    xlink:type="simple">Wilson, Andrew. Solar System Log. London: Jane’s, 1987. A compilation of piloted and unpiloted lunar and planetary space flights up to mid-1985 by all spacefaring nations. A well-illustrated chronology of the history, spacecraft, mission, and discoveries of all deep-space exploration missions.

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