<P> The exact time of the liftoff varies from source to source and is mentioned as 05: 30: 42 Moscow Time or 07: 22 Moscow Time . </P> <P> At peak acceleration Laika's respiration increased to between three and four times the pre-launch rate . The sensors showed her heart rate was 103 beats / min before launch and increased to 240 beats / min during the early acceleration . After reaching orbit, Sputnik 2's nose cone was jettisoned successfully; however the "Block A" core did not separate as planned, preventing the thermal control system from operating correctly . Some of the thermal insulation tore loose, raising the cabin temperature to 40 ° C (104 ° F). After three hours of weightlessness, Laika's pulse rate had settled back to 102 beats / min, three times longer than it had taken during earlier ground tests, an indication of the stress she was under . The early telemetry indicated that Laika was agitated but eating her food . After approximately five to seven hours into the flight, no further signs of life were received from the spacecraft . </P> <P> The Soviet scientists had planned to euthanise Laika with a poisoned serving of food . For many years, the Soviet Union gave conflicting statements that she had died either from asphyxia, when the batteries failed, or that she had been euthanised . Many rumours circulated about the exact manner of her death . In 1999, several Russian sources reported that Laika had died when the cabin overheated on the fourth orbit . In October 2002, Dimitri Malashenkov, one of the scientists behind the Sputnik 2 mission, revealed that Laika had died by the fourth circuit of flight from overheating . According to a paper he presented to the World Space Congress in Houston, Texas, "It turned out that it was practically impossible to create a reliable temperature control system in such limited time constraints ." </P> <P> Over five months later, after 2,570 orbits, Sputnik 2--including Laika's remains--disintegrated during re-entry on 14 April 1958 . </P>

Laika the dog is the first animal in space