The first human-made object to touch the moon was Luna-2, a USSR spacecraft launched in 1959. As the first spacecraft to reach the surface of another astronomical object, Luna-2 holds an important place in history. For the first time, people could interact with the moon rather than simply observing it (as Luna-2 left a small crater on the moon).

Let's see how the first ever mission to the moon worked.

The Luna-2 Spacecraft prior to launch
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Reaching the Moon

The moon is only about one quarter of the size of Earth, but actually reaching it is no small feat. After getting off of the ground and into space (a feat that requires a large rocket to begin with), a vehicle must accelerate to a speed faster than that required to orbit the Earth by a large measure. Then, the spacecraft must survive a trip through both Van Allen belts, which are rings of very high energy radiation trapped in the magnetic field of Earth. These belts can destroy unprotected electronics via ionizing radiation dose. Finally, after 400,000 kilometers, a spacecraft can reach the moon.

But attempting to reach the surface is another matter entirely. After arriving at the moon, the spacecraft must slow down into an orbit around the moon before descending to the surface. The moon has no significant atmosphere, so in order to prevent crashing into a rock at several kilometers per second, a spacecraft must still slow down after de-orbiting, using only rocket thrusters to come to a stop on the lunar surface. The moon isn't a small object by any means, and such still has significant gravity, which results in significant speed gained that must be eliminated via propulsion before landing.

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In fact, landing on the moon itself is such a challenge that the first spacecraft to travel to the moon did not even attempt to land: Instead, this vehicle (Luna-2) simply crashed into the surface at a high speed. This maneuver completely destroyed the spacecraft and the corresponding upper rocket stage but still provided valuable data on the way down, and served as the first ever mission the moon.

Luna-2

The Luna-2 spacecraft was a follow-up to the Luna-1 impactor mission, which was a similar spacecraft that had missed the moon and traveled into an orbit around the sun, where it remains to this day. Previous Luna missions had been destroyed in launch vehicle failures.

Like Luna-1, Luna-2 was a mostly sphere-shaped spacecraft. It contained several scientific instruments, including various radiation sensors and a magnetometer, a device that can measure magnetic fields. It also had several external antennas onboard, allowing it to send electromagnetic signals back to Earth all the way until impact with the lunar surface.

Artist rendition of Luna-2 just before impact
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There was no nuclear reactor/battery or solar cells onboard. This spacecraft was powered only by batteries that could not be recharged - not that they needed to be recharged, since the spacecraft hit the moon in less than 2 days. Luna-2 also had no onboard thrusters or any other kind of propulsion. As such, it had no way of slowing down its rapid descent onto the moon once it detached from its carrier rocket stage.

Luna-2 also carried an interesting payload sometimes called an "artificial comet". Once on a trajectory to the moon, Luna-2 (as Luna-1 had) released a large cloud of sodium gas. What was essentially a small bomb detonated onboard Luna-2, vaporizing sodium metal and creating a large gas cloud that spread out the back of the spacecraft. This gas cloud then reflected sunlight back to Earth, producing a large sunlit cloud several hundred kilometers across that could be seen from Earth.

Luna-2 Gas Cloud as seen from Earth. This allowed observers to track the spacecraft with ordinary telescopes alongside radio transmissions.
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If you were in southern California or Arizona a few days before this past Christmas, you saw something like this as a SpaceX Falcon-9 rocket took off from Vandenberg Air Force Base. Los Angeles and San Diego were already in the dark as the sun had set, but the rocket several dozen kilometers up was still above the sunset, causing the massive amount of gas exhaust to become illuminated and light up the night sky.

This rocket launch was visible throughout a large portion of the far southwest US about a month ago. This effect with the lit-up gas being extremely visible is very close to what Luna-2 did. I had the privilege of accidentally seeing this launch light up the sky while driving through some farms.
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Luna-2 Mission Highlights

On September 12th, 1959, the 400 kilogram Luna-2 took off from Kazakhstan (then part of the USSR) onboard a Vostok rocket. The Vostok rocket was derived from the R-7 intercontinental ballistic missile (meant to carry nuclear payloads), and a modified version of this vehicle later carried Yuri Gagarin into orbit on the first manned spaceflight.

The R-7 ICBM was the original basis for the orbital rockets that carried the first Soviet spacecraft
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This rocket shown launched Yuri Gagarin into space as the first human in orbit, and is very similar to the vehicle that launched Luna-2
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Because the spacecraft had no onboard propulsion, there was no need to enter a temporary parking orbit around Earth. Luna-2 never orbited the planet: Instead, it was sent on a direct transfer to the moon, following a hyperbolic trajectory that would have led it on an escape trajectory from Earth if the moon hadn't violently interfered.

On an extremely fast transfer trajectory, Luna-2 sped towards the moon along with its detached upper rocket stage, sending transmissions that could be received on Earth. Onboard radiation sensors verified that presence of the previously observed Van Allen radiation belts. These belts are full of high-energy electrons and protons revolving around the earth via the ambient magnetic field, which can cause damage to spacecraft electronics if not mitigated. The onboard magnetometer also showed the lack of a significant lunar magnetic field.

After 36 hours, Luna-2 achieved what no previous spacecraft had achieved and struck the surface of the moon, travelling several kilometers per second upon impact. Needless to say, not much of the vehicle survived, and radio transmissions immediately ceased. The last signal was received when the spacecraft was only about 50 kilometers above the surface - just a few seconds from direct impact. About half an hour later, Luna-2's upper stage (which had been placed in a very similar trajectory as a consequence of sending Luna-2 to the moon) also impacted the moon in a different spot. The end result of the mission was two new craters in the lunar surface.

This partial map of the moon shows several landing sites, including the impact site of Luna-2
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Luna-2 was quickly followed by Luna-3, which took the first ever pictures of the far side of the moon, the first time anyone had ever seen that part of the surface. To follow was the rest of the space race: the first people in space, several lunar landers, interplanetary missions, and the eventual Apollo landings, arguably the pinnacle of space exploration.

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Luna-2 stood out to me as the first manmade object to touch the surface of another world. Even if it was just an impactor, I find it incredible that this kind of thing could be done in the late-1950s without the advanced computers, solar panels, and sensors modern spacecraft rely on. This spacecraft holds a very important place in the history of space exploration.

I hope you learned something new about Luna-2. Let me know if you have any questions or comments, or if I got something wrong.

Thanks for reading!

Sources for additional reading:
Zarya Luna-2 Page
NASA Luna-2 Page
Luna-2 Wikipedia Entry
History Today Luna-2 Article