Near space

As the high atmosphere those higher areas of the Earth's atmosphere are called, where the air density and the air pressure drops below a technically largely meaningless amount.

• All air layers above the tropopause - for example, from the point of view of classical meteorology or of gliding
• The thermal and ionosphere - eg due to reflections in the process of telemetry or radio navigation, or direct electrodynamic interactions and other nichtgravitativen perturbations on Earth satellites
• The exosphere - for example, aspects of solar-terrestrial interactions ( solar wind, geomagnetic field ) and the magnetosphere

As a "free atmosphere ", however, those layers of air called that are higher than the Peplopause, or have more than 2 km distance from the ground. Beyond this base layer can be neglected for many meteorological effects, the influence of bottom friction.

In the early days of space travel, the density of the terrestrial upper atmosphere has been greatly underestimated, thereby braking the first earth satellite was much stronger than expected and the planned service life was to set optimistic. On average, the atmosphere above about 200 km orbital altitude was about 7 times denser than expected from previous research.

In the interplanetary space - eg flights to Mars - or for re-entry and return of a probe to Earth the upper atmosphere of planets can be used to brake the missile. These non -hazardous orbital maneuvers of aerobraking but must be dosed very precisely.