The Apollo Missions were a series of spaceflight missions conducted by the United States between 1961 and 1972. The goal of the Apollo program was to land humans on the Moon and bring them safely back to Earth. The most famous mission was Apollo 11, which saw Neil Armstrong become the first human to set foot on the Moon in 1969. Other notable missions included Apollo 8, which was the first mission to orbit the Moon, and Apollo 13, which was famously aborted due to an oxygen tank explosion. The term 'moonshots' is often used to refer to ambitious projects that require a great deal of effort and resources to achieve.