Orbital decay
From Free net encyclopedia
Orbital decay is the process of prolonged reduction in the height of a satellite’s orbit due to drag produced by an atmosphere. The drag intensifies during periods of high solar activity and sunspots, due to frequent collisions between the satellite and surrounding air molecules. The drag experienced by the object is proportional to the solar activity at the time.
A principal example of orbital decay is the Earth’s atmosphere during solar maxima (sunspots). The Earth's atmosphere causes drag up to a hundred kilometers higher than the drag during solar minimums.
Orbital drag resulting in a satellite falling onto a neighboring planet is described by the following sequence:
- Large solar activity -> Increases drag -> Orbital speed decreases -> less orbital height -> Experiences denser atmosphere -> increased heat -> usually burns on entry