Near space is the region of Earth's atmosphere that lies between 65,000 and 325,000-350,000 feet (20 to 100 km) above sea level, above where a commercial airliner flies but below the realm of an orbiting satellite.
Near space is the region of Earth's atmosphere that lies between 65,000 and 325,000-350,000 feet (20 to 100 km) above sea level, encompassing the stratosphere, mesosphere, and thermosphere. A more understandable definition would be above where a commercial airliner flies but below the realm of an orbiting satellite.