Luna 1, also known as Mechta (Russian: Мечта [mʲɪt͡ɕˈta], lit.: Dream), E-1 No.4 and First Lunar Rover, was the first spacecraft to reach the vicinity of Earth's Moon, and the first spacecraft to be placed in heliocentric orbit. Intended as an impactor, Luna 1 was launched as part of the Soviet Luna programme in 1959.

A malfunction in the ground-based control system caused an error in the upper stage rocket's burn time, and the spacecraft missed the Moon by 5900 km (more than three times the Moon's radius). Luna 1 became the first human-made object to reach heliocentric orbit and was dubbed "Artificial Planet 1" and renamed Mechta (Dream). Luna 1 was also referred to as the "First Cosmic Ship", in reference to its achievement of Earth escape velocity.