Short answers, pulled from the story.
Laika died from overheating during the fourth orbit of her flight on the 3rd of November 1957. The central "Block A" core of Sputnik 2 failed to separate as planned, which disrupted the thermal control system and caused the cabin temperature to rise to 40 degrees Celsius. The true cause was not publicly confirmed until scientist Dimitri Malashenkov revealed it at the World Space Congress in Houston, Texas, in October 2002.
No. Laika's survival was never expected because the technology to re-enter the atmosphere had not yet been developed at the time of her launch. Soviet scientists had planned to euthanise her with poisoned food, but she died from overheating before that could happen.
Laika was a stray mongrel found wandering the streets of Moscow. Soviet scientists specifically chose Moscow strays because they believed such animals had already developed resilience to extreme cold and hunger. She was approximately three years old and weighed around 5 kilograms.
Before launch, Laika's heart rate was 103 beats per minute; it surged to 240 beats per minute during peak acceleration. After three hours of weightlessness, her pulse settled back to 102 beats per minute, though the recovery took three times longer than in ground tests, indicating significant stress. Early telemetry showed she was agitated but still eating before signals ceased approximately five to seven hours into the flight.
The mission triggered widespread protests in Western countries. In the United Kingdom, the National Canine Defence League called for a minute's silence for each day Laika remained in space, and the RSPCA received protests before Radio Moscow finished announcing the launch. Demonstrators gathered outside the United Nations in New York. In 1998, Oleg Gazenko, one of the scientists who prepared Laika for the mission, stated: "We did not learn enough from this mission to justify the death of the dog."
A statue at Star City, the Russian Cosmonaut training facility, was created in 1997 and depicts Laika with her ears erect. The Monument to the Conquerors of Space in Moscow, built in 1964, also includes her. A third monument was unveiled on the 11th of April 2008 at the Moscow military research facility that prepared her flight. Tributes in popular culture include the 2007 graphic novel Laika by Nick Abadzis, which won multiple Eisner Awards, and a 2025 Eurovision-competing song by Norwegian singer Emmy titled "Laika Party."