3 ms·

> 1) it’s not true, and it becomes less true over time. Gravitational perturbations change the orbital planes of the debris. I can't imagine gravitational pert

> 1) it’s not true, and it becomes less true over time. Gravitational perturbations change the orbital planes of the debris. I can't imagine gravitational perturbations in LEO are going to significantly alter eccentricity. I'm trying to find some data that supports this, will report back.

GlenTheMachine 7y ago
Well, to be clear, when I say "gravitational perturbations" I don't mean GRAVITATIONAL perturbations ;) I mean any terms other than the strict 2-body problem dynamics: gravitational perturbations, third body gravitational effects, solar pressure, atmospheric drag, especially acting on non-spherical bodies, etc. See: https://www.researchgate.net/publication/292745544_Perturbations_in_orbital_elements_of_a_low_earth_orbiting_satellite https://www.researchgate.net/publication/292745544_Perturbat...
- mumblemumble 7y ago
  So, my imagination is lacking, so let me make sure I've got this right: The main gravitational perturbation you're thinking of isn't interaction with other small satellites or Earth's varying density; a bigger effect is going to be because the Moon, which is also moving relative to everything else is also a part of the equation. Out of curiosity, wouldn't atmospheric drag have a circularizing effect on eccentric orbits? I'd have guessed that, since drag is greatest when the satellite is at its perigee, it's going to have a much larger relative effect on the apogee.
  - GlenTheMachine 7y ago
    I am making no claim about what effects would be bigger (other than atmospheric drag, which is always the biggest effect in LEO). All I’m saying is that in general, all those nonlinear effects we tend to ignore, when integrated over long periods of time, tend to make orbits change their eccentricity and inclination, and that makes them more of a collision hazard because the relative velocity is higher than it would be if they were in more similar orbits to the thing they collide with.

GlenTheMachine 7y ago

Well, to be clear, when I say "gravitational perturbations" I don't mean GRAVITATIONAL perturbations ;) I mean any terms other than the strict 2-body problem dynamics: gravitational perturbations, third body gravitational effects, solar pressure, atmospheric drag, especially acting on non-spherical bodies, etc. See: https://www.researchgate.net/publication/292745544_Perturbations_in_orbital_elements_of_a_low_earth_orbiting_satellite https://www.researchgate.net/publication/292745544_Perturbat...

mumblemumble 7y ago
So, my imagination is lacking, so let me make sure I've got this right: The main gravitational perturbation you're thinking of isn't interaction with other small satellites or Earth's varying density; a bigger effect is going to be because the Moon, which is also moving relative to everything else is also a part of the equation. Out of curiosity, wouldn't atmospheric drag have a circularizing effect on eccentric orbits? I'd have guessed that, since drag is greatest when the satellite is at its perigee, it's going to have a much larger relative effect on the apogee.
- GlenTheMachine 7y ago
  I am making no claim about what effects would be bigger (other than atmospheric drag, which is always the biggest effect in LEO). All I’m saying is that in general, all those nonlinear effects we tend to ignore, when integrated over long periods of time, tend to make orbits change their eccentricity and inclination, and that makes them more of a collision hazard because the relative velocity is higher than it would be if they were in more similar orbits to the thing they collide with.