Sputnik 2

In 1955, engineer Mikhail Tikhonravov created a proposal for "Object D", a satellite massing to , about a fourth of which would be devoted to scientific instruments. 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. Work began on the project in February with a launch date of latter 1957, in time for the International Geophysical Year. The design was finalized on 24 July. By the end of 1956, it had become clear that neither the complicated Object D nor the 8A91 satellite launch vehicle version of the R-7 ICBM under development to launch it would be finished in time for a 1957 launch. Thus, in December 1956, OKB-1 head Sergei Korolev proposed the development of two simpler satellites: PS, Prosteishy Sputnik, or Primitive Satellite. The two PS satellites would be simple spheres massing and equipped solely with a radio antenna. The project was approved by the government on 25 January 1957. 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. With only three weeks to prepare, OKB-1 had to scramble to assemble a new satellite. While PS-2 had been built, it was just a ball, identical to PS-1. Fortunately, the R-5A sounding rocket had recently been used to launch a series of suborbital missions carrying dogs as payloads. 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. Upon reaching orbit, the final stage or Blok A would detach from the satellite. No provision was made for the dog's recovery. ==Spacecraft==

Sputnik 2 was a cone-shaped capsule with a base diameter of that weighed around , though it was not designed to separate from the rocket core that brought it to orbit, bringing the total mass in orbit to . Passenger Laika ("Barker"), formerly Kudryavka (Little Curly), was the part-Samoyed terrier chosen to fly in Sputnik 2. Accordingly, Sputnik 2 carried two spectrophotometers, one for measuring solar ultraviolet rays and one for measuring X-rays. 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. Korolev agreed, but as there was no more room on the satellite proper, the instrument was mounted on the Blok A and given its own battery and telemetry frequency. Engineering and biological data were transmitted using the Tral_D telemetry system, which would transmit data to Earth for 15 minutes of each orbit. ==Launch preparations==

Sputnik 2's launch vehicle, the R-7 ICBM (also known by the system's GRAU index 8K71) was modified for the PS-2 satellite launch and designated 8K71PS. 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. Laika was put in the payload container mid-day 31 October, and that night, the payload was attached to the rocket. The container was heated via an external tube against the cold temperatures at the launch site. ==Mission==

postage stamp "Спутник-2" Sputnik 2 was launched at 02:30:42 UTC on 3 November 1957 from LC-1 of the NIIP-5 Test Range via Sputnik 8K71PS rocket (the same pad and rocket that launched Sputnik 1) The sensors showed her heart rate was 103 beats/min before launch and increased to 240 beats/min during the early acceleration. 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. 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 day. In October 2002, Dimitri Malashenkov, one of the scientists behind the Sputnik2 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." Because of the size of Sputnik 2 and its attached Blok A, the spacecraft was easy to track optically. In its last orbits, the combined body tumbled end over end, flashing brightly before it was incinerated over the north Atlantic after circling the Earth 2,370 times over the course of 162 days. == Results==

Geopolitical impact Massing , Sputnik 2 marked a dramatic leap in orbital mass over Sputnik 1 It was clear now that the Soviets had missiles far superior to any in the American arsenal, 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. Animal rights groups at the time called on members of the public to protest at Soviet embassies. Others demonstrated outside the United Nations in New York. Laboratory researchers in the U.S. offered some support for the Soviets, at least before the news of Laika's death. Experimental data The cosmic ray detector transmitted for one week, going silent on 9 November when its battery was exhausted. 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. Per two articles in the Soviet newspaper Pravda, the particle flux increased with altitude as well. It is likely that Sputnik 2 was detecting the lower levels of the Van Allen Belt when it reached the apogee of its orbit. However, because Sputnik 2 telemetry could only be received when it was flying over the Soviet Union, the data set was insufficient to draw conclusions, particularly as, most of the time, Sputnik 2 traveled below the Belt. Thus, the Soviet Union missed out on its chance to get credit for the scientific discovery, which ultimately went to James Van Allen of the State University of Iowa, whose experiments on Explorer 1 and Explorer 3 first mapped the radiation belts that now bear his name. As for the ultraviolet and X-ray photometers, they were calibrated such that they were oversaturated by orbital radiation, returning no usable data. ==Surviving examples==

A USSR-built engineering model of the R-7 Sputnik 8K71PS (Sputnik II) is located at the Cosmosphere space museum in Hutchinson, Kansas, United States. The museum also has a flight-ready backup of the Sputnik 1, as well as replicas of the first two American satellites, Explorer 1 and Vanguard 1. A replica of Sputnik 2 is located at the Memorial Museum of Cosmonautics in Moscow. ==See also==