In November 3, 1957, the Soviet Union attempted to repeat its own success by launching the second orbital spacecraft in human history, Sputnik 2 - so named after its predecessor, Sputnik, which had been launched just a month before, drawing attention from around the world. Sputnik 2 had a first of its own: there was a dog, Laika, aboard, which scientists hoped to keep alive for ten days until the fragile little craft re-entered Earth's atmosphere. Ultimately this mission failed, although there were some positive side effects for science, including the detection of the Van Allen radiation belt.
When the Soviet government realized that Sputnik-1 had captivated not only its own public but the Western countries as well, it rushed into production a second spacecraft, Sputnik-2, intended to pick up where its predecessor had left off. While hastily arranged, not all components of the mission were mere afterthoughts. Special instruments would take measurements of X-ray and ultraviolet radiation in orbit. In addition, and more significantly, the craft would take a life form into space. This decision to include a dog was intended to confirm to doubters in the astronautic community that living beings could, indeed, survive in space; it had the additional effect of handing the Soviet government a ready-made explanation of how the vehicle was much more advanced than its immediate predecessor, Sputnik-1. Three dogs were chosen for the purpose, including a rescued stray, Laika, who was ultimately selected as the test subject.
Early spacecraft - even those which carried human beings into orbit several years later - were small and clumsy machines compared to today's (admittedly aging) designs. Sputnik 2 was 12 feet long and 6 feet wide, a volume large enough to contain several measuring instruments as well as the specially sealed compartment housing Laika. After its launch into orbit, aboard a converted R-7 intercontinental ballistic missile (the same type used to launch the original Sputnik the previous month), Soviet scientists hoped to operate the craft in orbit for ten days, during which they would continually monitor Laika's body functions. Since no provision had been made for a survivable landing capsule, Laika's fate was already sealed; indeed, the same scientists had included poison-laced food to kill the dog rather than force her to undergo the terror of burning up in re-entry.
This was not to be. The spacecraft's insulation was torn during launch; worse, its internal heating controls malfunctioned. Rather than survive in good health for over a week, Laika perished from heat exhaustion within a matter of hours. (The manner of her death was not publicly announced at the time and revealed by scientists only after the collapse of the Soviet Union). Scattered protests followed by groups who argued that the Soviet decision to send a dog to certain death in orbit constituted animal cruelty.
Despite Laika's fate, Sputnik-2 survived to circle the Earth 2000 times. For the first six days, its onboard batteries powered the instruments, allowing various scientific observations - and, in the process, detecting the Van Allen radiation belt, although this data would not be properly processed until after the belt's discovery had already been formally credited to the American Explorer satellites. Afterward, however, the batteries exhausted, the craft was abandoned to drift in orbit. In April 1958, Sputnik-2's orbit decayed and it plummeted into the atmosphere, burning up, in April 1958. By that time, the Soviet program had moved on to Sputnik-3, and now faced competition for its monopoly over Earth orbit in the form of the first successful American space program, Explorer.