What is the distance from ground level to outer space?

1 Answer
Feb 4, 2016

100 km


If you above the surface of the Earth at an altitude of 100 km one is considered to be in space according to the Fédération Aéronautique Internationale (FAI). It is referred to as the Kármán line.

The height of this imaginary boundary was calculated by the aeronautical scientist Theodore von Karman. He indicated that conventional vehicles would have insufficient aerodynamic lift to stay aloft once they reached this altitude. They will need to travel faster than their orbital velocity.

If you travel above this line you would be classified as an astronaut. This International boundary is also used for
world records and treaties.

In comparison a modern passenger airliner can cruise at around 40000 ft above sea level ie approximately 12 km. The International Space Station is at an altitude of 400 km.