Launched by the Soviet Union via a modified R-7 intercontinental ballistic missile, Sputnik 2 was a 4-metre-high (13 ft) cone-shaped capsule with a base diameter of 2 metres (6.6 ft) that weighed around 500 kilograms (1,100 lb), though it was not designed to separate from the rocket core that brought it to orbit, bringing the total mass in orbit to 7.79 tonnes (17,200 lb).

Though Laika died shortly after reaching orbit, Sputnik 2 marked another huge success for the Soviet Union in The Space Race, lofting a (for the time) huge payload, sending an animal into orbit, and, for the first time, returning scientific data from above the Earth's atmosphere for an extended period.

Upon learning that this spacecraft would outmass the announced American satellite by nearly 1,000 times, Soviet leader Nikita Khrushchev advocated for the proposal, which was approved by the government in Resolution #149-88 of 30 January 1956.

[3] Immediately following the launch, Nikita Khrushchev asked Sergei Korolev to prepare a Sputnik 2 in time for the 40th anniversary of the Bolshevik revolution in early November, just three weeks later.

[6] Details of the conversation vary, but it appears likely that Korolev suggested the idea of flying a dog, while Khrushchev emphasised the importance of the date.

Korolev simply requisitioned a payload container used for these missions and had it installed in the upper stage of its R-7 launching rocket directly beneath the PS-2 sphere.

Again, OKB-1 borrowed from the sounding rocket program, choosing from ten candidates provided by the Air Force Institute of Aviation Medicine that were already trained for suborbital missions.

[2] Both Laika and Albina had telemetry wires surgically attached to them before the flight to monitor respiration frequency, pulse, and blood pressure.

Laika was chained in place and fitted with a harness, a bag to collect waste, and electrodes to monitor vital signs.

Moreover, solar output is unpredictable and fluctuates rapidly, making sub-orbital sounding rockets inadequate for the observation task.

These instruments were provided by Professor Sergei Mandelstam of the Lebedev Institute of Physics and installed in the nose cone above the spherical PS.

In addition, Sergei Vernov, who had completed a cosmic ray detector (using Geiger counters) for Object D, demanded that the instrument his Moscow University team (including Naum Grigoriev, Alexander Chudakov, and Yuri Logachev) had built also be carried on the flight.

[3]: 163  8K71PS serial number M1-2PS arrived at the NIIP-5 Test Range, the precursor to the Baikonur Cosmodrome, on 18 October 1957 for final integration of the rocket stages and satellite payload.

After three hours of weightlessness, Laika's pulse rate had settled back to 102 beats/min,[12] three times longer than it had taken during earlier ground tests, an indication of the stress she was under.

[14] 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.

[18] In the United Kingdom, the National Canine Defence League called on all dog owners to observe a minute's silence on each day Laika remained in space, while the Royal Society for the Prevention of Cruelty to Animals (RSPCA) received protests even before Radio Moscow had finished announcing the launch.

The experiment reported unexpected results the day after launch, noting an increase in high-energy charged particles from a normal 18 pulses/sec to 72 pulses/sec at the highest latitudes of its orbit.