From: snidely.too@gmail.com   
      
   Snidely noted that:   
   > JF Mezei asserted that:   
   >> Sanity check:   
   >>   
   >> If there were no atmosphere/drag, a satellite at 163km that is going at   
   >> 28,080kmh and reduces it speed by 1kmh, would simply drop in altitude   
   >> and now be at a lower orbit, correct?   
   >>   
   >> Theoretically, it could progressively reduce its speed and drop in   
   >> altitude and end up going 28,440km in a orbit 100m above surface. Correct?   
   >>   
   >>   
   >> Now, let bring is a purely theoretical chinese boosters called CZ-5B   
   >> that is uncontrolled in a 163*301km orbit and bring back atmosphere.   
   >>   
   >> With every perigee having a bit of drag how is the orbit changed? Is   
   >> only Apogee loweree? Both are changed equally? or does Apogee lose more   
   >> altitide than perigee with tendency to circularize?   
   >>   
   >> If it circularizes, is it correct to state that the length of time spent   
   >> at/near perigee altitude (and thus getung drag) increases?   
   >>   
   >> Since in an elliptical orbit, the object goes faster than required at   
   >> perigee (hence having enough "oumph" to climb back up to apogee), I am   
   >> curious at how the object eventually comes to a point where  drag lasts   
   >> long enough to bleed enough speed to turn off orbital mechanics and turn   
   >> on ballustic re-entry.   
   >>   
   >> Is there a magic altitude below which atmpsphere is instantly much more   
   >> dense, so the minute perigee drops below that altitude, it bleeds too   
   >> much speed to climb out of altitude that has drag and it is sayonara?   
   >>   
   >> Or is re-entry much more subtle and gradual?   
   >   
   > The rule of thumb is that to raise one extremum of the orbit, you do the burn   
   > at the other extremum.  Atmospheric drag at perigee is the equivalent of a   
   > retrograde burn, so I'd expect apogee to be lowered.   
   >   
   > As for the speed, remember that drag increases with speed.  It's a nice   
   > differential equation to figure out the relative, um, impacts of short-fast   
   > drag events vs long-slow drag events.  You can probably do it quickly in   
   > Wolfram, but I'm not a Wolfram user.   
   >   
   > The CZ-58 booster's perigee is well below the orbit of the ISS, but IIRC from   
   > shuttle days the apogee is still within the bounds of measurable drag.   You   
   > might also consider the orbit of the Falcon 9 2nd stage recently retrieved   
   > near Seattle; I suspect it was a lower apogee, especially since it was a   
   > Starlink launch.  Hmmm, I see shell 1 is being loaded at 550 km/340 mi, but I   
   > haven't yet found the 2nd stage apogee; maybe I'll replay some of the launch   
   > videos and scan the telemetry display.   
      
   Today's launch was orbiting at 208 km at T+22 and 293 km at T+65   
   (deploy).   
      
   /dps   
      
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   The presence of this syntax results from the fact that SQLite is really   
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