Sputnik 2 was the second spacecraft launched into space by the Soviet Union on November 3, 1957, following the successful launch of Sputnik 1 one month earlier. Unlike the small metal sphere of Sputnik 1, which carried only a radio transmitter, Sputnik 2 was six times more massive and carried scientific instruments, making it the first spacecraft capable of conducting scientific measurements in orbit. Sputnik 2 is most famously known for carrying Laika, a female dog and the first living creature to travel to space.[2]