With the launch of the first artificial Earth satellites, scientists gained the ability to study outer space—previously inaccessible to them—through direct measurements. But these were only the first steps within a very tiny region of the solar system...
And above the horizon, the Moon shone brightly—familiar to everyone since childhood. With the invention of telescopes, it became closer to people, who discovered “seas,” mountains, and craters on it. But only one side of the Moon—always facing the Earth—was visible. The far side remained a “mystery behind seven seals.” In fact, even the nature of the Moon’s surface caused fierce debates. Some scientists believed the Moon was covered with a thick layer of dust, several meters deep. Others argued that it consisted of rocks somewhat similar to terrestrial tuffs. During one of these discussions, S. P. Korolev took a piece of paper and wrote decisively: “The Moon is solid,” signing it. He gave the paper as a keepsake to a proponent of the “lunar dust” theory.
Of course, only space probes could resolve such speculative disputes.
With the creation in the Soviet Union of a powerful launch vehicle capable of placing spacecraft into Earth orbit, the specialists led by S. P. Korolev naturally desired to reach the Moon. But to do this, the capabilities of the rocket had to be expanded—to give it new qualities. To place a satellite into Earth orbit, a speed of about 8 km/s—the so-called first cosmic velocity—is sufficient. But to escape Earth’s gravity, this speed must be increased to 11.2 km/s.
So, first of all, the launch vehicle’s power had to be increased. This challenge was solved by adding an extra stage to the rocket. At the same time, the design bureau of S. P. Korolev developed the first spacecraft for exploring the Moon.
On January 2, 1959, the first-ever launch toward the Moon took place. “Luna 1,” or as journalists dubbed it, “Dream,” passed close to the Moon and became the first artificial satellite of the Sun in history. During the flight, scientific instruments conducted measurements in outer space (from Earth to the Moon’s orbit), which were transmitted back to Earth via a radio telemetry system. Interestingly, the probe's flight could also be observed visually—a special device mounted on the final stage of the launch vehicle (which followed almost the same trajectory as the separated probe) released a sodium cloud at an altitude of about 100,000 km. This artificial comet was seen by people in many countries.
On September 12, 1959, the automatic station “Luna 2” was launched toward our planet’s satellite. Two days later, it reached the Moon and delivered a pennant bearing the emblem of the USSR to its surface. For the first time, a path had been laid from Earth to the Moon, and the eternal calm of another celestial body was disturbed.
“Luna 1” and “Luna 2” were not very complex in design. They were intended to solve specific tasks: testing and verifying the accuracy of launching spacecraft onto interplanetary trajectories, checking the feasibility of maintaining radio communication over long distances, and exploring the properties of space between the Earth and the Moon and near the Moon. During their flights, the magnetic fields of Earth and the Moon, radiation belts, cosmic rays, and meteoric particles were studied.
The automatic interplanetary station “Luna-3” was fundamentally new. For the first time, an automatic space probe was equipped with an orientation system, and solar panels were used as a power source for the instruments. The AMS (automatic interplanetary station) was also equipped with a photo-television device.
The new station was tasked with flying around the Moon, “looking” at its far side and photographing it, and then transmitting the images from space upon its return to Earth. That’s why the orientation system was installed. It included optical sensors that could “see” the Sun and the Moon, and orientation thrusters that kept the station in a strictly defined position, directing the lens of the photo-television device toward the surface of the Moon’s far side.
The photo-television device itself was unusual. It was not just a camera, but also a developing system and a transmitter (through the onboard radio link) of the processed images.
The solar panel configuration was also unique. The thing is, along the entire flight trajectory—except during the photography segment—the station wasn’t oriented toward the Sun. At the same time, to complete its mission, its chemical batteries required constant recharging. After complex calculations that took into account the overall design of the AMS and the thermal regulation requirements, an optimal shape for the solar panels was chosen. It allowed the generation of nearly equal current regardless of the station’s position relative to the Sun.
The launch of “Luna-3” on October 4, 1959, was a salute to the second anniversary of the start of the space age. On October 7, the automatic interplanetary station photographed the far side of the Moon from a distance of 60,000 km and transmitted a series of photographs to Earth, where scientists eagerly awaited them. Of course, today these images leave much to be desired. But they were the first. After decoding them, specialists obtained unique scientific data. The images showed both previously unseen areas of the Moon’s far side and a small region of already known terrain. This made it possible to correlate the previously unknown features of the lunar surface with known ones and thus determine their coordinates. It turned out that the far side of the Moon, unlike the near side, had few “seas” and was dominated by mountainous regions.
As a result of the first flights to the Moon, it was established that it lacks a magnetic field and radiation belts. Measurements of the overall cosmic radiation flux, carried out along the flight path and near the Moon, provided new data on cosmic rays and particles, as well as on micrometeoroids in open space. This information made it possible to move on to the creation of even more complex and more advanced space probes.
MARINA MARCHENKO, engineer
Depicted in the inset are the automatic interplanetary stations “Luna-1,” “Luna-2,” and “Luna-3.” The diagram shows the structure of the automatic interplanetary station “Luna-3.” The numbers indicate: 1. Window for photographic devices. 2. Scientific research instruments. 3. Thermal shields. 4. Solar panel sections. 5. Louvers for the thermal regulation system. 6. Antenna. 7. Solar sensor. 8. Orientation system thruster.