Luna 2: The First Successful Spacecraft

Besides stars and constellations, we like to watch videos and hear stories about spacecraft and space probes as they bring us out of this planet, even only in our thoughts.

Luna 2 was the first successful spacecraft that reached the Moon’s surface and the first human-made object contacted with another celestial body. It is actually the 6th of the Soviet Union’s Luna program spacecraft launched to the Moon. It was initially named Second Soviet Cosmic Rocket and called by the contemporary media as Lunik 2.

About Luna 2 spacecraft

It was a sphere-shaped spacecraft with five antennae extended from one hemisphere. There are instrument ports that protruded from the sphere’s surface. September 12-13, 1959 were historical dates for the Soviet Union and the world, as Luna 8K72 s/n I1-7B rocket was launched and followed a direct path to the Moon.

There were radio transmitters used to send telemetry information to the Earth, and the spacecraft released sodium gas cloud for visual tracking and observation to track its activity and movement. The Moon’s east of Mare Imbrium near the Aristides, Archimedes, and Autolycus craters was impacted by the spacecraft on September 13, 1959.

Luna rocket upper stage

To conduct various tests while on its way to the Moon, Luna 2 carried five instruments of different types. The scintillation counters used to measure any ionizing radiation, the Cherenkov radiation detectors to measure electromagnetic radiation from charged particles. The Geiger Counter’s primary purpose was to determine the electron spectrum of the Van Allen radiation belt. The spacecraft has three STS-5 gas-discharge counters attached to the outside of an airtight container. And lastly, a three-component fluxgate magnetometer like Luna 1’s but with dynamic range reduced by a factor of 4 to ±750 gammas to make the quantization uncertainty into ±12 gammas. Silver-zinc and mercury-oxide batteries power the probe’s instrumentation.

There were Soviet pennants on the probe and the Luna 2 rocket. The surfaces of the two sphere-shaped pennants in the probe were covered by 72 pentagonal elements with a pattern like that of the later used by association footballs. There was an explosive charge at the center, designed to shatter the sphere, to send pentagonal shields in all directions.

Titanium alloy was used for each pentagonal element; the center regular pentagon featured Soviet Union’s State Emblem with the Cyrillic letters СССР (“USSR”) engraved below and was surrounded by five non-regular pentagons which were each engraved with СССР СЕНТЯБРЬ 1959 (“USSR SEPTEMBER 1959”). The third pennant was similar engravings on aluminum strips, embossed on the Luna 2 rocket’s last stage.

The Mission

The primary objectives of the Luna 2 mission include the measurement of the temperature and pressure inside the vehicle, the study of the gas components of interplanetary matter and the Sun’s corpuscular radiation, measurement of the Earth’s and the Moon’s magnetic fields, the study of space’s meteoric particles, and the study of the distribution of heavy nuclei in primary cosmic radiation: and the study cosmic rays other properties.

What happened to Luna 1?

If Luna 2 succeeded in its mission, then there was Luna 1. But what has happened to Luna 1?

Although Luna 1 was the first artificial object to reach the Earth’s escape velocity on January 2, 1959, it separated from its 1472 kg carrier rocket’s third stage. The third stage is 5.2 m long and 2.4 m in diameter.

replica of Luna 1 exhibited in the "Kosmos" pavilion

Luna 1 was launched from Site 1/5 at the Baikonur Cosmodrome at 16:41 GMT by a Luna 8K72 rocket. The first three stages operated nominally, but the engineers did not trust automated systems to control the engine burns, so they used a radio to communicate to the rocket. Unfortunately, the signal to stop firing the engine Block E stage was sent too late and caused Luna 1 to impart an extra 175 m/s.

Consequently, on January 4, 1959, the spacecraft passed within 5,995–6,400 kilometers (3,725–3,977 mi) of the Moon’s surface. After its 34-hour flight, Luna 1 became the first human-made object to leave Earth’s orbit on January 6.

Luna 1 has a battery designed for a minimum of 40 hours flight, but it lasted for 62 hours and ran out of power on January 5, 1959, when it was 597,000 kilometers (371,000 mi) from Earth, making it impossible to track further. Meanwhile, if you want to know more about the moon and its shadows, click the given link.