Sputnik 2 was the second spacecraft launched into Earth orbit, on November 3, 1957, and the first to carry a living animal in orbit - a dog, named Laika. It was a 4-meter (13 foot) high cone-shaped capsule with a base diameter of 2 meters (6.6 feet). 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. The pressurized cabin on Sputnik 2 allowed enough room for her to lie down or stand and was padded. An air regeneration system provided oxygen; food and water were dispensed in a gelatinized form. Laika was fitted with a harness, a bag to collect waste, and electrodes to monitor vital signs. Early telemetry indicated Laika was agitated but eating her food. It was believed Laika survived for only a few hours instead of the planned ten days because of the heat.
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| This cover was produced by Kniga with a backdated 3 November 1957 Moscow postmark. |
In October 2002 it was revealed by Russian sources that Laika had already died after a few hours from overheating and stress, not suffocation as is commonly believed. The mission provided scientists with the first data on the behavior of a living organism in the space environment. The orbit of Sputnik 2 decayed and it reentered Earth's atmosphere on 14 April 1958 after 162 days in orbit. The mission planners did not provide for the safe return of the spacecraft or its passenger, making Laika the first orbital casualty.
Sputnik 2 detected the Earth's outer radiation belt in the far northern latitudes, but the significance of the elevated radiation was not realized. In Australia, Professor Harry Messel intercepted the signals but the Soviets would not provide the code and the Australians would not send the data. In 1958, with Sputnik 3, they began to cooperate and confirmed the findings of the US satellites Explorer 1, 3, and 4.
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| Set of four Sputnik 2 stamps were issued. |
