To err is human, but it's a real problem when it happens on a space mission. Over the years there have been several missions that didn't go well. The phrase "Houston, we have a problem." is well known for a reason. With so much engineering, math, physics and yes, even politics involved in making a space mission work, it's no surprise that some of them failed in big ways.
One of them, the Luna 16 from the Former Soviet Union, crashed into a mountain on the moon. The reason it was an epic fail? It happened just days before the Apollo 11 launch that brought Neil Armstrong and Buzz Aldrin to the moon. Check out this video to hear more about space missions that missed the mark.