The number of miles required to reach outer space depends on whom is asked: the space industry lists 62 miles; NASA sets the boundary at 76 miles. Others place the marker at an astronomical 13 million miles.
Determining the boundary of outer space is fraught with scientific and political issues. The 62-mile boundary adopted by the Federation Aeronautique Internationale (FAI) is the point at which the atmosphere is so thin that commercial aircraft can no longer operate. The issue of overflight rights for satellites, however, has prevented the United States from recognizing this limit. NASA uses 76 miles, the point at which space shuttles switch from thrusters to maneuvering with air surfaces when returning to earth. At 13 million miles, Earth's gravity loses it dominance.