What is Sputnik II?

Launched in 1957, Sputnik 2 was the second artificial satellite to be put into Earth orbit and the first satellite to carry a living passenger, a dog named Laika (a Russian word meaning "barker").

Sputnik 2 launched on a modified version of the booster used for Sputnik 1 and entered low Earth orbit on Nov. 3, 1957. According to NASA, part of the orbiter's nosecone failed to properly detach, resulting in the failure of the on-board climate system. Temperatures inside the craft rose to over 40 degrees Celsius, probably contributing to the death of its canine occupant, who survived about two days instead of the planned 10.