1992 Volume 68 Issue 6 Pages 568-576
We review the sheath which is produced around a moving object in space.The sheath in space is grouped from different point of view; one is ambient plasma density, another is potential of the object. In terms of the ambient plasma density, neutral particles collide with electrons inside the sheath in the lower ionosphere below 90km. Shape of the sheath which is formed around moving object are distorted which is totally different from stationally laboratory plasma.In the high altitude, where ambient plasma density is less than 103els/cc, the satellite is surrounded by photoelectron in the sunlight.
When we look at the sheath from the view point of the magnitude of the voltage applied to it, the sheath is divided into two groups; low voltage and high voltage regimes. Low voltage regime is a conventional satellite sheath. High voltage regime is encountered in bombardment of the spacecraft by auroral electrons under low density plasma or in electrodynamic tether system. Study about the highly biased large electrode is important for the future solar power station.