Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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

  1. Apr 27, 2009 #1
    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 travelling 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.
     
  2. jcsd
  3. Apr 27, 2009 #2

    mgb_phys

    User Avatar
    Science Advisor
    Homework Helper

    It doesn't take any fuel to keep moving - there is nothing to stop it.
     
    Last edited: Apr 28, 2009
  4. Apr 28, 2009 #3
    At 8km/s, if you fly through the atmosphere, probably your craft will burn
     
  5. Apr 28, 2009 #4

    DaveC426913

    User Avatar
    Gold Member

    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.)
     
  6. Apr 28, 2009 #5

    DaveC426913

    User Avatar
    Gold Member

    This is not relevant.
     
  7. Apr 28, 2009 #6

    Nabeshin

    User Avatar
    Science Advisor

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: How does the Satellite manage to stay in earth's orbit?
  1. Satellite orbit (Replies: 13)

Loading...