Tank on the MoonDuring the 1960s, the United States and the Soviet Union were engaged in a feverish competition to be the first to set foot on the moon.

We know who won this race, but less about a secret chapter. The Soviets many not have sent a man to the moon, but they successfully guided two small robots by remote control from the earth.

For 16 months between 1970 and 1973, these Lunokhods traveled more than thirty miles over the moon's surface.

With the declassification of the former USSR space archives, along with recollections by several of the key participants in the Lunokhod program, the true story of the Russian lunar robots can finally be told.

Watch the full documentary now