USSR 1957 Sputnik 1

On October 4, 1957, the Soviet Union launched the world's first artificial satellite, Sputnik 1, signaling the beginning of the Space Race. Sputnik 1 supplied scientists with valuable information regarding the characteristics and ion density of the Earth's upper atmosphere, as well as insights into radio frequency behavior in space, which helped determine if astronauts could maintain communication with a base on Earth.

This cover was produced by KNIGA. It features a Moscow postmark dated October 4, 1957; however, the postmark was backdated because the successful launch of Sputnik 1 was not publicly announced until later.
Photo: A replica of Sputnik 1 on display at an exhibition.
The successful development of large rockets during World War II spurred interest in artificial satellite research in the late 1940s, primarily in the United States and the Soviet Union. The space age is often regarded as having commenced with the launch of Sputnik 1 by the USSR in October 1957.

Photo Top: The orbital trajectory of Sputnik 1, the first artificial satellite in the world. Bottom: An image of Sputnik 1 in orbit.
This cover features an unofficial Moscow M-127 postmark dated October 4, 1957.
Photo: A map of the United States displaying the anticipated orbital trajectory of Sputnik 1.
This is a First Day Cover featuring the Sputnik 1 stamp, designed by Ye. Gundobin. The stamp, notable for its indigo color, was issued on November 4, 1957, to commemorate the launch of the world’s first artificial satellite.
An overprinted Sputnik 1 stamp in a bright blue color was released on December 28, 1957.
Photo: An image depicting the cross-section of the Sputnik 1 satellite.
This above covers were produced by KNIGA, featuring stamps of Sputnik 1. The Moscow postmark dated October 4, 1957, is backdated because the successful launch of Sputnik 1 was not made public until after it had taken place.
(Reference from Sputnik 1)