Question

Why the orbit of artificial satellite is kept outside the earth’s atmosphere?

Answer 1

So, that its energy may not decay due to friction of the atmosphere.

Answer 2

Artificial satellites are placed in orbits outside Earth's atmosphere for several crucial reasons:

1. Atmospheric Drag: Earth's atmosphere extends to about 1,000 kilometers (620 miles) above the surface, gradually thinning out as altitude increases. Satellites in lower orbits would experience atmospheric drag, which would gradually slow them down and cause their orbits to decay, eventually leading them to re-enter and burn up in the atmosphere.

2. Stable Orbits: To maintain a stable orbit and function effectively, satellites need to be in a region where atmospheric drag is minimal or nonexistent. This allows them to remain in orbit for long periods without frequent adjustments or risk of deorbiting.

3. Effective Communication and Observation: Many satellites are designed for communication, weather monitoring, or Earth observation. Being above the atmosphere allows them to have an uninterrupted line of sight to their ground stations or targets, without atmospheric distortion or interference.

4. Temperature and Radiation: The upper atmosphere is more stable in terms of temperature and less subject to the intense heating and cooling cycles that can occur closer to the surface. Additionally, being above the atmosphere helps satellites avoid some of the effects of atmospheric radiation, although they still need to contend with cosmic radiation and solar radiation.

5. Space Environment: Certain orbits, such as geostationary orbits, are specifically chosen for their unique properties, like maintaining a fixed position relative to the Earth's surface. These orbits are well outside the atmosphere and enable the satellite to serve its purpose, such as constant communication with specific regions.