How does the Satellite manage to stay in earth's orbit?

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Discussion Overview

The discussion centers on the mechanics of satellites maintaining their orbits around Earth, specifically addressing the required velocity and the role of fuel in sustaining that motion. Participants explore concepts related to orbital mechanics, inertia, and the effects of atmospheric resistance.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant notes that an object needs to travel at around 8 km/s to remain in orbit and questions whether all satellites maintain this speed and how they manage fuel.
  • Another participant asserts that once in motion, a satellite does not require fuel to maintain its velocity due to the absence of air resistance in space.
  • Concerns are raised about the potential for a craft traveling at 8 km/s to burn up if it encounters the atmosphere.
  • A participant references Newton's First Law to explain that an object in motion will remain in motion unless acted upon by an external force, emphasizing the lack of air resistance in space.
  • Newton's cannonball is cited as an illustrative example of orbital mechanics and the reasons satellites do not simply fall back to Earth.

Areas of Agreement / Disagreement

Participants express varying views on the necessity of fuel for maintaining orbital velocity, with some agreeing on the principles of inertia while others raise concerns about atmospheric interactions. The discussion does not reach a consensus on these points.

Contextual Notes

Participants do not fully explore the implications of atmospheric drag at different altitudes or the specifics of fuel usage for orbital adjustments, leaving these aspects unresolved.

Who May Find This Useful

This discussion may be of interest to those studying orbital mechanics, aerospace engineering, or physics, particularly in understanding the dynamics of satellite motion and the principles of inertia.

yalgaar
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I have read that an object needs to have a velocity of around 8km/s to not fall back on Earth and to stay on orbit.

Based on the above, are all our human made sattelites constantly traveling at around 8km/s to not fall back on earth? Is so doen't it need a lot of fuel? Does it store all this fuel? I think I am missing something basic here.
 
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It doesn't take any fuel to keep moving - there is nothing to stop it.
 
Last edited:
At 8km/s, if you fly through the atmosphere, probably your craft will burn
 
yalgaar said:
I have read that an object needs to have a velocity of around 8km/s to not fall back on Earth and to stay on orbit.

Based on the above, are all our human made sattelites constantly traveling at around 8km/s to not fall back on earth? Is so doen't it need a lot of fuel? Does it store all this fuel? I think I am missing something basic here.

Newton's First Law: an object in motion will tend to stay in motion. There is no air - and therefore no air resistance - in space. Once you get the craft up to speed, it will continue on its merry way forever until it encounters something to stop or slow it (such as faint whiffs of atmosphere in low orbit.)
 
pixel01 said:
At 8km/s, if you fly through the atmosphere, probably your craft will burn
This is not relevant.
 

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