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That's what I was reading as well from places like http://spaceflightnow.com/ http://spaceflightnow.com/

• justin66 11y ago
  Here's a question. IF it's in the ISS's orbital plane and it finished its burn, so it basically had enough oomph to reach ISS with a little boost in altitude... doesn't this imply that it's travelling in a longer ellipse, with higher altitude apogee than ISS? I'm probably visualizing this wrong but it seems as though it might have the potential to pass by ISS every now and then.
  • lmm 11y ago
    > Here's a question. IF it's in the ISS's orbital plane and it finished its burn, so it basically had enough oomph to reach ISS with a little boost in altitude... doesn't this imply that it's travelling in a longer ellipse, with higher altitude apogee than ISS? It won't have completely "finished its burn" until it's docked. But I don't think it would ever have a higher apogee than the ISS, because that's just a waste of fuel. If it's just short of docking then I'd expect it to be either in a same-shaped orbit slightly lower than the ISS (i.e. almost circular) ready for a Hohmann transfer, or in an ellipse whose apogee just touches the ISS' orbit ready for a circularization burn. Even if the orbits do cross an accidental collision is extremely unlikely - the objects are very small compared to how fast they're travelling, their motion is predictable years ahead, and the Progress is at an altitude where its orbit will naturally decay in a few months if nothing is done.