The Luna ProgramThe Luna program comprised 49 Soviet probe launches targeted toward the Moon, from 1959 to 1976. It had a high failure rate--24 of the 49 missions either failed to launch properly, or failed to escape Earth orbit, and of the remaining 25, many crashed into the Moon, missed the Moon, or had other significant hardware and/or control failures--and was ultimately upstaged by NASA's Apollo 11 manned Moon landing, but did achieve some noteworthy firsts in space exploration, and some interesting catastrophic failures! I also love the bulky, busy Soviet space designs. Soviet space probes were typically pressurized, unlike NASA probes, which were usually left open to vacuum. Just to highlight some of the missions:
(All images from NASA unless stated otherwise)
Luna 1 (1959)
A ground control error caused this tiny 361 kg probe (similar in design to Luna 2, below) to miss the Moon by 5,900 km. It then drifted off and became the first man-made object to orbit the Sun (see end of this article for more). It was also the first human craft to achieve escape velocity!
Luna 2 (1959)

Similar in design to Luna 1, but with 29 additional kg of instruments, including some of those nifty antennae. Luna 2 was the first man-made instrument to hit the Moon. A smashing success! After this milestone, later missions would focus on orbiting or landing safely on the Moon.
Luna 3 (1959)

Even smaller (278.5 kg) but much more sophisticated, Luna 3 flew past the Moon, getting the first images of the dark side of the Moon, a world never before seen by humans! You can see a lot of these nice old Soviet space program Moon photos
here.
Luna 4 (1963)

Missed the Moon by over 8000 km and ended up in Earth orbit. 1,422 kg--look at all that gear! This design would be used through Luna 9.
Luna 5 (1965)
Had a gyroscope problem, couldn't fire its thruster correctly, and thus inadvertently crashed into the Moon, raising a 220x80 km debris cloud for about ten minutes, visible from Earth observatories.
Luna 6 (1965)
Controller error prevented the engine from switching off, so it over-fired in its retro phase and missed the Moon by 161,000 km, drifting into solar orbit.
Luna 7 (1965)
Seemed to be doing well and was braking for a soft landing, but lost control (the astronavigation system's camera had been set at the wrong angle, so it lost sight of Earth, one of its reference points) and crashed into the Moon's surface.
Luna 8 (1965)
Was doing even better, and deployed air bags for landing, but one popped on a mounting bracket (a down side of having all that exposed gear, I suppose!). The ruptured air jetted the craft into a spin, and it crashed into the Moon's surface. So close! Darn air bags.
Luna 9 (1966)
The first successful Moon landing--or landing on anything other than Earth, for that matter! The landing capsule deployed like this on the lunar surface

(isn't that cool-looking???) and sent back the first photos from the Moon's surface. For some reason, the Soviets didn't release the images right away; a British observatory was able to pick up the data signal, noticed it was the same signal type used by newspapers for transmitting news photos, and so simply "downloaded" the images themselves and published them ahead of the Soviets! Scooped!
Luna 10 (1966)

This ugly 1,582 kg probe became the first artificial satellite of a non-Earth body, going into lunar orbit and taking lots of sensor readings and stuff.
Luna 11 (1966)

This sweet-looking 1,640 kg probe also went into lunar orbit. It had a TV camera set to take lots of pictures, but couldn't point it at the Moon due to a "foreign object" lodged in one of the attitude control thrusters! (Banana? :p) Luna 12 completed the photo-taking mission successfully.
Luna 15 (1969)

This ugly 5,600 kg behemoth launched three days before Apollo 11, but the astronauts beat it to the Moon. As they were preparing for take off from the Moon to return to Earth, Luna 15 was going in for landing, but contact was abruptly lost near the calculated landing altitude; they think it probably smashed into an unforeseen mountain. My theory: Apollo 11 astronauts shot it down with robo death rays! The follow-up mission, Luna 16, successfully landed on the Moon, scooped up some Moon dust, and launched a capsule of it back to Earth--but this dirt exchange had already been scooped by the Apollo 11 return. Luna 18, the same type of sample return craft, would crash in 1971, probably also into a mountain; the official Soviet comment was "the lunar landing in the complex mountainous conditions proved to be unfavorable." :o
Luna 17 (1970)

This successful craft consisted of a rover mounted on top of a lunar lander; on landing, the remote-controlled rover deployed, driving 10.5 km over 11 days. Here's a TV image it took, looking back at its lander, with the ramps deployed:

image from Jerward (
source)
Here's the "Lunokhod" rover: check out those hamster wheels (it was actually powered by solar cells, though)!

In 1973, the roughly identical Luna 21 Lunokhod rover lasted much longer--some 140+ days; its mission only ended because it accidentally rolled into a crater and got its solar panels covered by dust, and thus lost power.
Luna 23 (1974)

Had a drill to get a deeper soil sample, but apparently the instrument was damaged somehow in the landing, and it couldn't get anything.