Satellite Reentry: Examining Newtonian Gravity

[Jack3145]

The path of a satellite reentering the atmosphere from a very high orbit has two components, one gravitational and the other from the atmosphere. Could there be a discussion of the two separate components using Newtonian gravity with gravity as:

g = GM/r^2

that change with elevation as a function of time.

 

[Naty1]

There may also be a velocity component from the satellite's rotational velocity...anyway the atmosphere acts as a variable resistance (drag) in a direction opposite the velocity.

the complication is that air resistance and gravity vary with altitude and air resistance varies with speed...and likely with temperature as well...

Try wikipedia,
http://en.wikipedia.org/wiki/Orbital_spaceflight

and see "RE-ENTRY for a brief discussion of some practical considerations...it's not a simple theoretical situation underlying your question. For one thing, a satellite in free fall will burn up...

There are practical equations for computing air resistance...I researched some for wind force on a boat while anchored...it varied as the square of wind speed...people had computed/measured constants for different boat shapes...

 

[sir-pinski]

Yes, there can definitely be a discussion of the two separate components using Newtonian gravity. The equation g = GM/r^2 represents the gravitational force exerted on an object by a large mass, such as the Earth, where G is the gravitational constant, M is the mass of the object, and r is the distance between the object and the mass. This equation shows that as the distance between the object and the mass decreases, the force of gravity increases.

In the case of a satellite reentering the atmosphere, the gravitational force from the Earth will decrease as the satellite gets closer to the surface. This is because the distance between the satellite and the Earth's center decreases, causing the force of gravity to decrease according to the inverse square law. As the satellite continues to descend, the force of gravity will continue to decrease until it reaches the surface.

However, the atmosphere also plays a significant role in the path of a satellite reentering the atmosphere. As the satellite descends, it will encounter increasing air resistance or drag from the atmosphere. This drag force will act in the opposite direction of the satellite's motion and will increase as the satellite gets closer to the surface. This means that the satellite will experience a deceleration due to the drag force, which will also affect its path.

In summary, both the gravitational force from the Earth and the drag force from the atmosphere will have a significant impact on the path of a satellite reentering the atmosphere. While the force of gravity will decrease with decreasing distance, the drag force will increase, causing the satellite to slow down and potentially change its trajectory. This complex interaction between Newtonian gravity and atmospheric drag must be considered when analyzing the path of a satellite reentering the atmosphere.