Photo by Eric Long, Smithsonian National Air and Space Museum	Milestone: First Artificial Satellite
	Date of Milestone: October 4, 1957
	Spacecraft: Sputnik 1
	Mission Operated by: USSR
	Spacecraft Location: Smithsonian Institution, National Air and Space Museum, Milestones of Flight Gallery

On October 4, 1957, the Soviet Union sent into orbit Sputnik 1, the first artificial satellite in history. Then a month later, an even larger and heavier satellite, Sputnik 2, carried the dog Laika into orbit.

Sputnik’s  launch came as an unnerving surprise to the United States. The space age had dawned and America’s Cold War rival suddenly appeared technologically superior.

The first U.S. effort to launch a satellite failed when its Vanguard rocket exploded during lift-off. Finally on January 31, 1958, a Jupiter-C rocket sent Explorer 1 into orbit. The space race was underway.

Design Features (in comparison to Explorer 1):

Sputnik 1	Explorer 1

• More than twice the size of a basketball, Sputnik was larger and heavier than Explorer. Only the striped section of Explorer contained the payload; the rear half was a solid-fuel rocket motor.
• Sputnik’s sphere was polished to a high sheen to aid in tracking by telescope. Explorer’s light and dark stripes helped control its temperature.
• Despite Sputnik’s streamlined appearance, it tumbled while in orbit. Explorer spun about its long axis, which extended its four flexible antennas.
• Sputnik contained two radio transmitters, which sent back the “beep-beep-beep” heard round the world. Explorer contained a cosmic ray detector, radio transmitter, and temperature and micrometeoroid sensors.

People:

Sergei P. Korolëv headed the design bureau that created the U.S.S.R.’s first intercontinental ballistic missile and Sputnik. He was adamant about making the satellite appear impressive, declaring, “This ball will be exhibited in museums!”

More Information:

• Learn more about Explorer 1
• Learn more about the U.S.-Soviet competition in space in the Space Race exhibition (Gallery 114).