The Ye-1 series of soviet lunar probes were the first attempt to reach the surface of the moon. Only one of four probes was successfully launched, receiving the name Luna 1 (also Lunik 1), but missed the moon.

The 361 kg Ye-1 probes consisted of a spherical, pressurized container. Five antennae extended from one hemisphere, while instrument ports protruded from the surface of the sphere. The probes were battery powered and contained radio equipment, a tracking transmitter, a telemetry system, five different sets of scientific devices for studying interplanetary space (including a magnetometer, Geiger counter, scintillation counter, and micrometeorite detector), and other equipment.

During the flight to the moon, the upper stage of the launch vehicle released a 1 kg sodium cloud for tracking purposes.

At the end of their journey, the Ye-1 probes would crash into the Moon, delivering two metallic pennants with the Soviet coat of arms.