Sputnik 2 carried Laika into space sixty-six years ago today. She was kept inside the cramped capsule for three full days prior to her launch from the Baikonur Cosmodrome. She died on her fourth low orbit around the Earth, roughly seven hours into the flight.

During the launch, surgically attached sensors recorded Laika's pulse as being three times its normal rate. She was breathing four times faster than she should have been. Due to the continuous trauma she was experiencing, both rates decreased only slightly over the next few hours. The temperature inside the capsule rose steadily. At the five hour mark, as the capsule thermometers rose above 90°F, her vital signs began to fail. Two hours later, she was dead.

Laika's corpse orbited the Earth some 2,570 times before disintegrating in the Earth's atmosphere on April 14, 1958.