4 October 1957 – Sputnik 1

Despite the somewhat difficult relations between Russia and the West in the last few years, it is worth looking back 65 years to October 1957 and the launch of the first artificial satellite Sputnik 1. This historic event, which caught many in the West by complete surprise, was the beginning of the space age. To mark it I have re-blogged my post from 2017 on this topic.

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Nearly sixty-five years ago , on 4 October 1957, the Soviet Union launched the first artificial satellite, Sputnik 1, into orbit around the Earth. This date was the beginning of the space age. On every day since there have been artificial satellites around the Earth. Now, in late 2022, there are over 6000 active satellites in orbit (source https://www.ucsusa.org/resources/satellite-database) and many times that number of defunct ones.

Sputnik 1 image credit NASA

Sputnik 1 consisted of a shiny metal sphere, 58.5 cm in diameter, made out of an aluminium alloy. Attached to the sphere were four radio aerials. Unlike later satellites, Sputnik 1 carried no scientific instruments and wasn’t fitted with any TV cameras to take pictures. It had no solar cells to generate electricity and was powered by three non-rechargeable batteries. Its only piece of equipment was a radio transmitter, which transmitted regular pulses on two different frequencies: 20 MHz and 40 MHz. Anybody with a short wave receiver tuned to either of these frequencies could pick up Sputnik’s signal as it passed overhead. Despite its small size, it was also possible to view the satellite just after sunset or just before sunrise through binoculars. It appeared as a faint rapidly moving point of light just about visible to the naked eye. The booster rocket, which at 26 metres longs was much larger than Sputnik, also remained in orbit. Being so large it was roughly as bright as the brightest stars and so was easy to spot.

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The end of the mission

Because Sputnik 1 had no power source such as solar cells to generate electricity, the batteries on board could not be recharged. After 22 days the spacecraft ran out of power and ceased transmitting, although it still remained in orbit and could be observed from Earth.

Sputnik 1 was placed in an elliptical orbit.  When it was closest to Earth (perigee) – it was 215 km in altitude and when it was at its its furthest (apogee) it was 939 km in altitude.

215 km is high enough to be classed as space, at this altitude there are still significant traces of the Earth’s atmosphere. Every time Sputnik 1 dipped into the lower part of its orbit, these thin traces of atmosphere slowed down the spacecraft, moving at 28,000 km/h, by friction.  This process,known as orbital-decay, caused Sputnik 1 to lose energy and move slightly closer to Earth. On 4 Jan 1958 Sputnik 1 had dropped down to an altitude of 150 km. At this point the traces of atmosphere slowed the spacecraft down to a speed at which it could no longer remain in orbit. Sputnik 1  then fell back to Earth, frictional heating causing it to burn up in the process.

Laika and Sputnik 2

On 3 November 1957, one month after the launch of Sputnik 1, the Soviets launched another spacecraft, Sputnik 2. Sputnik 2 was much larger than its predecessor and had instruments to measure electrically charged particles, x-rays and ultraviolet emissions from the Sun. It also carried a passenger – a female dog called Laika, who became the first living creature to go 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 was barely able to move. Sadly for Laika, it was a one way ticket. Sputnik 2 was placed into a similar elliptical orbit as Sputnik 1 and, like Sputnik 1, it was destined to burn up on its return back to Earth. In 1957 the technology for a spacecraft to return safely 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.

After the Sputnik-2 mission the official Soviet account was that 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 (Whitehouse 2002).  For political reasons, the Soviets had rushed the launch of Sputnik 2  and did not have the ability in November 1957 to keep the small 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.

Laika surrounded by other pioneers of early Soviet space exploration

For more on Sputnik 2, please visit https://explainingscience.org/2022/11/04/sputnik-2/

American Reaction

The year 1957 was during the cold war between the Eastern bloc – the Soviet Union and its allies – and the West. Before the launch of Sputnik, most people in America took for granted their country’s technological superiority. America had been the first country to develop the atomic bomb, led the way in computing and electronics and, in the years following the end of World War II, had been ahead of the Soviets in missile development. So most people naturally assumed that America would be the first country to place a satellite into orbit.

Front page of the New York Times from 5 October 1957- the day after the launch of Sputnik 1.

The launch of Sputnik 1 caught many in America by surprise and led a lot of people in America to fear that Soviet technology had not only caught up with but also overtaken that of America. Many were fearful of the potential military implications of the launch. If the Soviets had built a rocket which was powerful enough to launch a satellite into orbit, then the same rocket could be be used to attack America with nuclear weapons. For this reason, the period of time immediately after the Sputnik launch is often known as the “Sputnik Crisis”.

The Sputnik Crisis led to a big increase in US government funding for high technology industries such as missile defence. In February 1958, 4 months after the launch, president Dwight Eisenhower authorised the formation of the Advanced Research Projects Agency, later renamed the Defense Advanced Research Projects Agency (DARPA), within the Department of Defense  to develop emerging technologies such as missile defence for the U.S. military.

Dwight Eisenhower – Image credit Wikimedia commons

As well as the formation of DARPA, the Sputnik Crisis also led directly to the passing of the National Aeronautics and Space Act and the creation of the National Aeronautics and Space Administration (NASA), a civilian-led organisation concerned with America’s non-military efforts in space exploration

Vanguard 

The launch of Sputnik 2 caused widespread fear amongst many in the US government, who felt that the US was falling further behind the Soviets. This fear was compounded when the Americans attempted to launch their first satellite into orbit Vanguard Test Vehicle 3 (TV3) on 6 December 1957. The launch  was shown live on television all over the United States, but it proved to to be a PR disaster. Two seconds after lift off, the engines failed, the rocket fell back to the launch pad and the fuel tanks ruptured which caused the rocket to explode in a massive fireball.

Despite the failure of Vanguard, the Americans successfully launched Explorer 1 into orbit in February 1958, marking the start of the space race between the two great world superpowers.  . The impetus of the space race led the to the Soviets putting the first human into space in April 1961, and the Americans putting the first person on the Moon, in July 1969. I’ll talk about the early days of the space race in my next post.

Reference

Whitehouse, D (2002) First dog in space died within hours, Available at:http://news.bbc.co.uk/1/hi/sci/tech/2367681.stm (Accessed: 15 September 2022).