Re: Re: What Did I See?

From: George Roberts (
Date: Mon Jun 21 2010 - 20:16:52 UTC

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    > Heavens-Above has it at 109 miles perigee (176 km) so it should be nearing it's end-of-life within the next few weeks?
    Orbital mechanics are weird.  When you "instantly" speed up an object in earth orbit it makes the far side of the orbit farther from 
    the earth.  When you slow down an object in orbit at perigee, it doesn't affect the next perigee pass much but instead lowers 
    apogee.  This is often called "circularization" as the elliptical orbit is moving towards a circle. What you would expect is a lower 
    apogee each pass which means the satellite will move slightly slower each perigee pass.  In fact slower by the exact amount it was 
    slowed on the previous pass.  In reality it is more complicated because the slowing doesn't occur only at perigee but in a longer 
    So knowing nothing about this object's orbit I will say: no, it shouldn't be nearing it's end-of-life until the orbit is much more 
    circular.  I could be quite wrong!
    - George Roberts
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