Sputnik 2 (, ,
Satellite 2), or
Prosteyshiy Sputnik 2 (
PS-2, ,
Elementary Satellite 2) was the second
spacecraft launched into
Earth orbit, on 3 November 1957, and the first to carry a living animal, a
dog named
Laika. Sputnik 2 was a 4-metre (13 foot) high cone-shaped capsule with a base diameter of 2 meters (6.6 feet) that weighed around 500 kg, though it was not designed to separate from the rocket core that brought it to orbit, bringing the total mass in orbit to 7.79 tons. It contained several compartments for
radio transmitters, a
telemetry system, a programming unit, a regeneration and
temperature-control system for the cabin, and scientific instruments. A separate sealed cabin contained the dog Laika.