Replica Sputnik I Satellite, 1957.

Sputnik I launched from the Soviet Union on the 4th October 1957. It spent three months orbiting around Earth at 18,000mph (29,000kph). The satellite had a radio transmitter on board which beeped at regular intervals and anyone with a radio could tune into it as it zoomed overhead.

Sputnik I heralded the start of the space race between the USSR and the United States. The launch in particular was impressive. Sputnik I weighed a hefty 184 pounds and was heavier than anything the US was attempting to develop at the time. This meant that the rocket that launched the satellite was incredibly powerful. Americans perceived a growing technological gap between the two countries. The United States poured money into its space programme to try and catch up.

America finally launched its first satellite in January 1958, the Explorer. Despite the tensions of the Cold War, the launch of Sputnik and the space race led to technological developments in space travel that allowed humans to land on the Moon, developed the Space Shuttle programme and put space stations in Earth's orbit.

Sputnik I launched from the Soviet Union on the 4th October 1957. It spent three months orbiting around Earth at 18,000mph (29,000kph). The satellite had a radio transmitter on board which beeped at regular intervals and anyone with a radio could tune into it as it zoomed overhead.

Sputnik I heralded the start of the space race between the USSR and the United States. The launch in particular was impressive. Sputnik I weighed a hefty 184 pounds and was heavier than anything the US was attempting to develop at the time. This meant that the rocket that launched the satellite was incredibly powerful. Americans perceived a growing technological gap between the two countries. The United States poured money into its space programme to try and catch up.

America finally launched its first satellite in January 1958, the Explorer. Despite the tensions of the Cold War, the launch of Sputnik and the space race led to technological developments in space travel that allowed humans to land on the Moon, developed the Space Shuttle programme and put space stations in Earth's orbit.

Sputnik I launched from the Soviet Union on the 4th October 1957. It spent three months orbiting around Earth at 18,000mph (29,000kph). The satellite had a radio transmitter on board which beeped at regular intervals and anyone with a radio could tune into it as it zoomed overhead.

Sputnik I heralded the start of the space race between the USSR and the United States. The launch in particular was impressive. Sputnik I weighed a hefty 184 pounds and was heavier than anything the US was attempting to develop at the time. This meant that the rocket that launched the satellite was incredibly powerful. Americans perceived a growing technological gap between the two countries. The United States poured money into its space programme to try and catch up.

America finally launched its first satellite in January 1958, the Explorer. Despite the tensions of the Cold War, the launch of Sputnik and the space race led to technological developments in space travel that allowed humans to land on the Moon, developed the Space Shuttle programme and put space stations in Earth's orbit.

Sputnik I launched from the Soviet Union on the 4th October 1957. It spent three months orbiting around Earth at 18,000mph (29,000kph). The satellite had a radio transmitter on board which beeped at regular intervals and anyone with a radio could tune into it as it zoomed overhead.

Sputnik I heralded the start of the space race between the USSR and the United States. The launch in particular was impressive. Sputnik I weighed a hefty 184 pounds and was heavier than anything the US was attempting to develop at the time. This meant that the rocket that launched the satellite was incredibly powerful. Americans perceived a growing technological gap between the two countries. The United States poured money into its space programme to try and catch up.

America finally launched its first satellite in January 1958, the Explorer. Despite the tensions of the Cold War, the launch of Sputnik and the space race led to technological developments in space travel that allowed humans to land on the Moon, developed the Space Shuttle programme and put space stations in Earth's orbit.

Sputnik I launched from the Soviet Union on the 4th October 1957. It spent three months orbiting around Earth at 18,000mph (29,000kph). The satellite had a radio transmitter on board which beeped at regular intervals and anyone with a radio could tune into it as it zoomed overhead.

Sputnik I heralded the start of the space race between the USSR and the United States. The launch in particular was impressive. Sputnik I weighed a hefty 184 pounds and was heavier than anything the US was attempting to develop at the time. This meant that the rocket that launched the satellite was incredibly powerful. Americans perceived a growing technological gap between the two countries. The United States poured money into its space programme to try and catch up.

America finally launched its first satellite in January 1958, the Explorer. Despite the tensions of the Cold War, the launch of Sputnik and the space race led to technological developments in space travel that allowed humans to land on the Moon, developed the Space Shuttle programme and put space stations in Earth's orbit.

Sputnik I launched from the Soviet Union on the 4th October 1957. It spent three months orbiting around Earth at 18,000mph (29,000kph). The satellite had a radio transmitter on board which beeped at regular intervals and anyone with a radio could tune into it as it zoomed overhead.

Sputnik I heralded the start of the space race between the USSR and the United States. The launch in particular was impressive. Sputnik I weighed a hefty 184 pounds and was heavier than anything the US was attempting to develop at the time. This meant that the rocket that launched the satellite was incredibly powerful. Americans perceived a growing technological gap between the two countries. The United States poured money into its space programme to try and catch up.

America finally launched its first satellite in January 1958, the Explorer. Despite the tensions of the Cold War, the launch of Sputnik and the space race led to technological developments in space travel that allowed humans to land on the Moon, developed the Space Shuttle programme and put space stations in Earth's orbit.

Sputnik I launched from the Soviet Union on the 4th October 1957. It spent three months orbiting around Earth at 18,000mph (29,000kph). The satellite had a radio transmitter on board which beeped at regular intervals and anyone with a radio could tune into it as it zoomed overhead.

Sputnik I heralded the start of the space race between the USSR and the United States. The launch in particular was impressive. Sputnik I weighed a hefty 184 pounds and was heavier than anything the US was attempting to develop at the time. This meant that the rocket that launched the satellite was incredibly powerful. Americans perceived a growing technological gap between the two countries. The United States poured money into its space programme to try and catch up.

America finally launched its first satellite in January 1958, the Explorer. Despite the tensions of the Cold War, the launch of Sputnik and the space race led to technological developments in space travel that allowed humans to land on the Moon, developed the Space Shuttle programme and put space stations in Earth's orbit.

Sputnik I launched from the Soviet Union on the 4th October 1957. It spent three months orbiting around Earth at 18,000mph (29,000kph). The satellite had a radio transmitter on board which beeped at regular intervals and anyone with a radio could tune into it as it zoomed overhead.

Sputnik I heralded the start of the space race between the USSR and the United States. The launch in particular was impressive. Sputnik I weighed a hefty 184 pounds and was heavier than anything the US was attempting to develop at the time. This meant that the rocket that launched the satellite was incredibly powerful. Americans perceived a growing technological gap between the two countries. The United States poured money into its space programme to try and catch up.

America finally launched its first satellite in January 1958, the Explorer. Despite the tensions of the Cold War, the launch of Sputnik and the space race led to technological developments in space travel that allowed humans to land on the Moon, developed the Space Shuttle programme and put space stations in Earth's orbit.

Sputnik I launched from the Soviet Union on the 4th October 1957. It spent three months orbiting around Earth at 18,000mph (29,000kph). The satellite had a radio transmitter on board which beeped at regular intervals and anyone with a radio could tune into it as it zoomed overhead.

Sputnik I heralded the start of the space race between the USSR and the United States. The launch in particular was impressive. Sputnik I weighed a hefty 184 pounds and was heavier than anything the US was attempting to develop at the time. This meant that the rocket that launched the satellite was incredibly powerful. Americans perceived a growing technological gap between the two countries. The United States poured money into its space programme to try and catch up.

America finally launched its first satellite in January 1958, the Explorer. Despite the tensions of the Cold War, the launch of Sputnik and the space race led to technological developments in space travel that allowed humans to land on the Moon, developed the Space Shuttle programme and put space stations in Earth's orbit.

Sputnik I launched from the Soviet Union on the 4th October 1957. It spent three months orbiting around Earth at 18,000mph (29,000kph). The satellite had a radio transmitter on board which beeped at regular intervals and anyone with a radio could tune into it as it zoomed overhead.

Sputnik I heralded the start of the space race between the USSR and the United States. The launch in particular was impressive. Sputnik I weighed a hefty 184 pounds and was heavier than anything the US was attempting to develop at the time. This meant that the rocket that launched the satellite was incredibly powerful. Americans perceived a growing technological gap between the two countries. The United States poured money into its space programme to try and catch up.

America finally launched its first satellite in January 1958, the Explorer. Despite the tensions of the Cold War, the launch of Sputnik and the space race led to technological developments in space travel that allowed humans to land on the Moon, developed the Space Shuttle programme and put space stations in Earth's orbit.

Sputnik I launched from the Soviet Union on the 4th October 1957. It spent three months orbiting around Earth at 18,000mph (29,000kph). The satellite had a radio transmitter on board which beeped at regular intervals and anyone with a radio could tune into it as it zoomed overhead.

Sputnik I heralded the start of the space race between the USSR and the United States. The launch in particular was impressive. Sputnik I weighed a hefty 184 pounds and was heavier than anything the US was attempting to develop at the time. This meant that the rocket that launched the satellite was incredibly powerful. Americans perceived a growing technological gap between the two countries. The United States poured money into its space programme to try and catch up.

America finally launched its first satellite in January 1958, the Explorer. Despite the tensions of the Cold War, the launch of Sputnik and the space race led to technological developments in space travel that allowed humans to land on the Moon, developed the Space Shuttle programme and put space stations in Earth's orbit.

Sputnik I launched from the Soviet Union on the 4th October 1957. It spent three months orbiting around Earth at 18,000mph (29,000kph). The satellite had a radio transmitter on board which beeped at regular intervals and anyone with a radio could tune into it as it zoomed overhead.

Sputnik I heralded the start of the space race between the USSR and the United States. The launch in particular was impressive. Sputnik I weighed a hefty 184 pounds and was heavier than anything the US was attempting to develop at the time. This meant that the rocket that launched the satellite was incredibly powerful. Americans perceived a growing technological gap between the two countries. The United States poured money into its space programme to try and catch up.

America finally launched its first satellite in January 1958, the Explorer. Despite the tensions of the Cold War, the launch of Sputnik and the space race led to technological developments in space travel that allowed humans to land on the Moon, developed the Space Shuttle programme and put space stations in Earth's orbit.

Sputnik I launched from the Soviet Union on the 4th October 1957. It spent three months orbiting around Earth at 18,000mph (29,000kph). The satellite had a radio transmitter on board which beeped at regular intervals and anyone with a radio could tune into it as it zoomed overhead.

Sputnik I heralded the start of the space race between the USSR and the United States. The launch in particular was impressive. Sputnik I weighed a hefty 184 pounds and was heavier than anything the US was attempting to develop at the time. This meant that the rocket that launched the satellite was incredibly powerful. Americans perceived a growing technological gap between the two countries. The United States poured money into its space programme to try and catch up.

America finally launched its first satellite in January 1958, the Explorer. Despite the tensions of the Cold War, the launch of Sputnik and the space race led to technological developments in space travel that allowed humans to land on the Moon, developed the Space Shuttle programme and put space stations in Earth's orbit.