It is now 65 years since the launch of Sputnik 2 on November 3 1957 by the Soviet Union. It was only the second spacecraft to venture into space and followed the successful launch of Sputnik 1 one month earlier. Sputnik 1 was a small metal sphere whose only piece of equipment was a radio transmitter. Sputnik 2 was six times more massive than its predecessor and carried scientific instruments. It had a Geiger counter to measure electrically charged particles and two spectrophotometers to measure ultraviolet and x- rays. Short wave radiation is blocked by the Earth’s atmosphere from reaching the ground and can only be observed from space.
How the opacity of the atmosphere varies with wavelength – image credit Wikimedia Commons
The science team on Sputnik- 2 was headed by Sergei Vernov from Moscow state University. He had a long successful academic career and, like many Soviet scientists involved in their space programme, was virtually unknown in the West
Sergei Vernov (1910 -1982)
When Vernov and his team saw the data from Sputnik 2, they noticed significant fluctuations in the rates at which charged particles were picked up by the Geiger counter. They knew that the Sun had recently emitted a small flare, so they wrongly interpreted the fluctuations as due to the arrival of energetic solar particles.
In fact, Sputnik 2 was sampling different regions of the Earth’s magnetic field, and the fluctuations were due to the radiation belts surrounding the Earth. These later became known as the Van Allen belts, named after the American space scientist James Van Allen (1914 – 2006)
Image credit NASA
The orbit of Sputnik 2 is shown below. It reached its highest altitude (its apogee) when it was in the Southern Hemisphere. At this altitude it was well inside the inner Van Allen belt
The year 1957 was at the height of the cold war between the West and the Soviet bloc and there was very little scientific cooperation between the two sides of the divide. Had the Soviet scientists had access to the Geiger Counter data when Sputnik 2 was at the highest point of its orbit they may well have arrived at the correct conclusion . However, the data from the satellite when it was near its apogee could not be received from Soviet territory- as the satellite was below the horizon . The data was picked up by radio telescopes from Australia but, in order to prevent scientists outside the Soviet Union from making use of it, the data was encoded. Australian scientists asked the Soviets for the codes to interpret the data, but as expected the Soviets refused. In retaliation the Australians refused to pass the data they’d received across to Soviet scientists.
Had there been more cooperation between the West and the Soviets then perhaps the radiation belts surrounding the Earth would now be known as the Vernov belts.
However, Sputnik 2 is most famous for its passenger, a dog Laika who became the first living creature to venture into orbit.
Mockup of Laika in the Sputnik-2 capsule- image credit NASA
As you can see from the diagram above, it was a tight squeeze to get Laika into the capsule and for the duration of the spaceflight she would have been barely able to move. Sadly for Laika, her journey into space was always planned to be a one way ticket. Sputnik 2 was destined to burn up on its return back to Earth. In 1957 the technology for a spacecraft to return intact back to Earth from orbit did not exist. In addition, Sputnik 2 could only carry enough food, water and oxygen for Laika to survive for 7 days.
The official Soviet account was that the mission had gone to plan. Laika had survived a week in space and had been humanely killed by poisoning her seventh and final daily ration of food. This was the story which appeared in nearly all books on the early history of spaceflight written before 1990. After the fall of the Soviet Union in 1991, different accounts of the Sputnik 2 mission emerged. It was suggested that she had died much earlier in the mission from lack of oxygen, or when the cabin had overheated. This was confirmed in 2002, when Dimitri Malashenkov of the Institute for Biological Problems in Moscow stated that although she had survived the initial launch, she had died within a few hours from a combination of overheating and panic . For political reasons, the Soviets had rushed the launch of Sputnik 2 and did not have the ability in November 1957 to keep a space capsule at an even temperature.
Despite surviving for a few hours in orbit, Laika’s place in the history of space exploration is assured. The information from Sputnik-2 proved that a living organism could tolerate a substantial time in weightlessness and paved the way for later human spaceflights in the 1960s. Today there are monuments to Laika in various places in Russia.
Part of the frieze at the bottom of the massive Monument to the Conquerors of Space (Soviet Union 1964)