This Month in Physics History

Courtesy of NASA Sergei Korolev

October, 1957: Soviets launch first artificial satellite into Earth orbit

Fifty years ago, on October 4, 1957, the Soviet Union launched Sputnik, the first man-made satellite, shocking the American public and beginning the Space Age.
 
People had been dreaming of space travel for some time before the launch of Sputnik. In 1903 Russian rocket scientist Konstantin Tsiolkovsky showed mathematically that an artificial satellite was feasible, though the US paid little attention to his work. Rocketry developed over the next several decades, and the idea of spaceflight captured the public’s imagination.

In 1952, the International Council of Scientific Unions decided to establish the International Geophysical Year. The IGY was scheduled for 18 months from July 1957 to December 1958, chosen because solar activity would be at a high point during that time period. The “year” would be a sort of extravaganza of geophysical science, with many scientific studies planned.

As part of the IGY, ICSU called for Earth orbiting satellites to carry out scientific experiments during the year. In July 1955, the White House announced plans for the first satellite and called for proposals. In September, the Naval Research Lab’s Vanguard satellite was chosen. The Soviet Union also announced plans to launch an IGY satellite.

The Russian satellite effort was led by Sergei Korolev, though his name was kept secret until after his death in 1966. Korolev was born in 1907, and trained at university to become an aerospace engineer. In the 1930s he worked on developing long range missiles. In 1938, he was arrested on trumped-up charges and sent to prison; he spent the next few years in several forced labor camps, including one of the most dreaded in the gulag. During WWII he and other engineers were sent to prison design camps, where imprisoned engineers designed rockets for military use. After the war Korolev was released from prison and continued work on long range ballistic missiles.

In 1953, Korolev began work on the R7, the first intercontinental ballistic missile, which he successfully tested in August 1957. The powerful rocket was capable of launching satellites weighing more than a ton into orbit. The planned scientific payload (which later became Sputnik III) was not yet ready, but Korolev, hearing plans for Vanguard, was determined to beat the Americans into space, so he decided to proceed with the launch of a smaller satellite with no scientific instruments. The Soviets originally hoped to schedule the launch for September 17, the 100th anniversary of the birth of Tsiolkovsky; they were able to put their first satellite into orbit a just few weeks later.

Launched on October 4, 1957, Sputnik I was a shiny aluminum alloy sphere about the size of a beach ball. It weighed 184 pounds, much heavier than America’s planned Vanguard satellite. Sputnik, whose name comes from the Russian for “traveling companion,” orbited Earth once every 96 minutes, flying in an elliptical path that reached 141.7 miles from Earth at its closest approach, and 588 miles away at its farthest point. Amateur radio operators could easily pick up the signals it constantly sent out at 20 and 40 MHz. It continued circling the globe until January 1958.

The small beeping ball was enough to terrify the American public, which was taken by surprise by the satellite’s launch. US scientists tracked its course, and its signals were broadcast on radio and television. The satellite could even be seen from Earth with binoculars as it flew overhead. The public was afraid that since the Soviets could launch a satellite into space, then they could also launch missiles with nuclear warheads that could reach the US. Some people even believed that the satellite was spying on us, or that its meaningless beeps were actually some sort of code. President Eisenhower tried to calm the country, but his words were seen as a sign of unconcern, which angered the public even more.

Responding to the public panic that the Russians had beaten us into space, the Defense Department approved another satellite, Explorer, in addition to the Vanguard mission. About two months after the first Sputnik launch, the US, in a hurry to prove our own capabilities, attempted to launch Vanguard, but it exploded on the launch pad.

Finally, on January 31, 1958, the US made it into space with the successful launch of satellite Explorer I. Explorer I made one of the most important scientific discoveries of the international geophysical year, the Van Allen radiation belts, and the discovery was soon confirmed by Explorer-III, launched on March 26, 1958. On March 17, 1958, the Vanguard I satellite was launched. It weighed only about 3 pounds, and was about the size of a grapefruit.

Less than a month after the first Sputnik launch, the Soviet Union launched a second Sputnik satellite, this time carrying the first living passenger in space, a dog named Laika. This was followed by the May 15, 1958 launch of Sputnik III, which carried a variety of scientific instruments. The Russians went on to send the first human into orbit, on April 12, 1961. 

There are now thousands of man-made satellites orbiting Earth. Following Sputnik, fears that the US was losing the space race led to a drive to improve American scientific and engineering capabilities. The US government poured more funding into science, science education was emphasized in schools, and more people went into science and engineering careers. This October, we commemorate the 50th anniversary of Sputnik, and fifty years of scientific and technological innovation in the Space Age.